WO2006004160A1 - Light guide member, planar lighting apparatus using the light guide member, and bar-like lighting apparatus - Google Patents

Light guide member, planar lighting apparatus using the light guide member, and bar-like lighting apparatus Download PDF

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Publication number
WO2006004160A1
WO2006004160A1 PCT/JP2005/012504 JP2005012504W WO2006004160A1 WO 2006004160 A1 WO2006004160 A1 WO 2006004160A1 JP 2005012504 W JP2005012504 W JP 2005012504W WO 2006004160 A1 WO2006004160 A1 WO 2006004160A1
Authority
WO
WIPO (PCT)
Prior art keywords
light guide
light
guide plate
shape
groove
Prior art date
Application number
PCT/JP2005/012504
Other languages
French (fr)
Japanese (ja)
Inventor
Osamu Iwasaki
Original Assignee
Fuji Photo Film Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fuji Photo Film Co., Ltd. filed Critical Fuji Photo Film Co., Ltd.
Publication of WO2006004160A1 publication Critical patent/WO2006004160A1/en

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0015—Means for improving the coupling-in of light from the light source into the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/002—Means for improving the coupling-in of light from the light source into the light guide provided on the surface of the light guide or in the bulk of it by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces
    • G02B6/0021—Means for improving the coupling-in of light from the light source into the light guide provided on the surface of the light guide or in the bulk of it by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces for housing at least a part of the light source, e.g. by forming holes or recesses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0038—Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0045—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it by shaping at least a portion of the light guide
    • G02B6/0046—Tapered light guide, e.g. wedge-shaped light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/0028—Light guide, e.g. taper
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/003—Lens or lenticular sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0055—Reflecting element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
    • G02B6/0068—Arrangements of plural sources, e.g. multi-colour light sources
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0066—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form characterised by the light source being coupled to the light guide
    • G02B6/0073—Light emitting diode [LED]

Definitions

  • the present invention relates to a light guide member, a planar illumination device using the same, and a rod illumination device.
  • the present invention relates to a light guide member used in a backlight unit, a planar illumination device using the same, and a rod-like illumination device.
  • a liquid crystal display device uses a backlight unit that illuminates the liquid crystal panel by irradiating the back side of the liquid crystal panel (LCD).
  • the backlight unit uses components such as a light source for illumination, a light guide plate that diffuses the emitted light and irradiates the liquid crystal panel, and a prism sheet and a diffusion sheet that uniformize the light emitted from the light guide plate. Composed
  • a backlight unit of a large-sized liquid crystal television is mainly used in a so-called direct type in which a light guide plate is disposed immediately above a light source for illumination (for example, Japanese Utility Model Laid-Open No. 5-4133 (hereinafter referred to as Japanese Utility Model Laid-Open No. 5-4133)). And referred to as Patent Document 1)).
  • a plurality of cold-cathode tubes, which are light sources are arranged on the back of the liquid crystal panel, and the inside is a white reflective surface to ensure a uniform light distribution and the required brightness.
  • the liquid crystal panel needs to have a thickness of about 30 mm in the vertical direction.
  • Patent Document 2 a fluorescent lamp is embedded in a groove formed in a light guide plate having a substantially rectangular shape, a reflective sheet is disposed on the back surface of the light guide plate, and the amount of transmitted light is corrected on the exit surface of the light guide plate.
  • a surface light source device (backlight unit) formed by laminating a sheet, a light diffusion plate, and a prism sheet is disclosed.
  • Patent Document 3 discloses a concave portion for arranging a light source in order to obtain a bright backlight unit that can reduce the frame thickness of the liquid crystal display device and reduce the thickness thereof and has high light utilization efficiency.
  • a light guide (light guide plate) in which the shape of the cross section parallel to the width direction is a parabolic shape with the depth direction as the main axis is disclosed.
  • the light guide plates disclosed in Patent Documents 2 and 3 are all used to reduce the thickness, size, weight, power consumption, and cost of the liquid crystal display device.
  • One or a plurality of grooves are provided in the central portion, and the rod-shaped light source is accommodated in the groove.
  • the groove portion force is also directed toward the end surface so that the plate thickness gradually decreases, and the thickness is reduced. Has achieved.
  • Patent Document 4 in order to improve the liquid crystal backlight for a large liquid crystal display surface of a wall-mounted television, a plurality of light guide plates are arranged in parallel, and a predetermined number of linear light sources are arranged between the light guide plates. It has been arranged to achieve high brightness and achieve a highly uniform large backlight.
  • a cold cathode tube is used as a light source of the knock light.
  • knock light units have been proposed that use LEDs (light-emitting diodes) as light sources instead of cold-cathode tubes.
  • LEDs light-emitting diodes
  • Patent Document 5 JP-A-9-259623
  • at least one side of a plate-shaped light guide plate is used as a light source mounting side, and an appropriate number of concave light introducing portions are provided on the light source mounting side.
  • An invention relating to an LED light source module in which an LED lamp is opposed to each of the light introducing portions is disclosed.
  • Patent Document 5 a pair of light introducing portions are placed close to the light source mounting side, and the notch into the light source mounting side on the inner side that is adjacent to each other is brought to a right angle, and the notch into the light source receiving side on the outer side is made. It is formed as a concave surface approaching parallel, and a concave reflecting surface is provided between the pair of light introducing portions.
  • Patent Document 6 discloses a plate-shaped first light guide disposed opposite to the front side of an electro-optical panel, and a first guide.
  • a second light guide extending along the side end surface of the light body, a point light source for allowing light to enter from the end of the second light guide, and a second light source from the end of the second light guide.
  • An electro-optical device including an incident region limiting unit that prevents light from entering the light guide is disclosed.
  • the second light guide a rod-shaped (rectangular) translucent resin molded product is used, and point light sources are arranged at both ends of the light guide to provide a point-like shape. The light from the light source is guided into the second light guide, and the side wall force light of the light guide is emitted.
  • Patent Document 7 discloses a light guide made of a light-transmitting material as a light source, and a dot-like shape disposed at at least one end of the light guide.
  • a planar illumination device using a light source composed of a light source is disclosed.
  • the light guide is a light guide whose cross-sectional shape decreases as the cross-sectional shape is square, circular, or point-like light source power increases, and is arranged near the side end face of the rectangular light guide plate.
  • Patent Document 1 Japanese Utility Model Publication No. 5-4133
  • Patent Document 2 Japanese Patent Laid-Open No. 9-304623
  • Patent Document 3 JP-A-10-133027
  • Patent Document 4 Japanese Patent Laid-Open No. 2001-42327
  • Patent Document 5 Japanese Patent Laid-Open No. 9-259623
  • Patent Document 6 Japanese Unexamined Patent Publication No. 2001-110223
  • Patent Document 7 Japanese Unexamined Patent Publication No. 2000-268622
  • the lighting devices disclosed in these Patent Documents 5 to 7 employ a side light system in which light from a light emitting diode is incident on one side of a substantially rectangular light guide plate, and use of light from a light source
  • a side light system in which light from a light emitting diode is incident on one side of a substantially rectangular light guide plate, and use of light from a light source
  • the present invention has been made in view of the above circumstances, and an object of the present invention is thinner than a light guide plate using a cold-cathode tube and effectively utilizes light emitted from a point light source, particularly a light-emitting diode.
  • An object of the present invention is to provide a light guide member that can be used, a planar illumination device using the same, and a rod-like illumination device used in the planar illumination device.
  • another object of the present invention is to use a light guide member capable of emitting high-luminance illumination light that is uniform and has less unevenness, a planar illumination device using the same, and a planar illumination device using the same. It is in providing the rod-shaped illuminating device.
  • Still another object of the present invention is to provide a rod-like illumination device that can be optimally used for a thin light guide plate with high color reproducibility.
  • a first aspect of the present invention is a transparent light guide member, which has a rectangular light emission surface and is located on the opposite side of the rectangular light emission surface.
  • a transparent plate-shaped first light guide having a parallel groove parallel to one side of the rectangular light exit surface on the back surface, and a transparent second light guide having a columnar outer shape accommodated in the parallel groove.
  • the light guide member comprised from a body is provided.
  • the second light guide has a cross-sectional shape substantially the same shape as the parallel groove. It is preferable that a pair of light guides having a shape in which the outer diameter decreases from one end to the other end face is configured by connecting the end faces on the smaller outer diameter side.
  • the back surface of the first light guide has a pair of inclined back surfaces that are symmetrical with respect to a plane that includes the central axis of the parallel grooves and is perpendicular to the rectangular light exit surface, and the inclined back surface.
  • the central axis partial force has one or more structures that are inclined with respect to the rectangular light exit surface such that the thickness decreases toward the end in the direction orthogonal to the one side. It is preferable that it is the shape connected by the part.
  • an exposed surface exposed from the parallel groove of the second light guide is inclined with respect to the rectangular light exit surface. It is preferable that a prism row is formed on the exposed surface of the second light guide.
  • the cross-sectional shape perpendicular to the length direction of the second light guide of the light guide member of the present invention is a triangular shape, a circular shape, a shape obtained by cutting a part of an ellipse, or a part of a parabola.
  • the shape is preferred.
  • the second light guide has a groove in which light enters from both end faces in the length direction and becomes wider and deeper toward the center of both end face forces.
  • the second light guide is also incident on one end surface force in the length direction, and the width becomes wider toward the other end surface, the end surface force on the light incident side. It is preferable that both have grooves with a deeper depth.
  • the groove of the second light guide is preferably a V-shaped or U-shaped groove.
  • a second aspect of the present invention includes the light guide member of the first aspect of the present invention and a point light source, and the light from the point light source from both end faces of the second light guide. It provides a surface illumination device that receives light.
  • the point light sources are arranged on both end faces of the second light guide body!
  • the planar illumination device of the present invention preferably further includes a light guide for guiding the light from the point light source to the end surface of the second light guide.
  • the point light source power LED is preferable.
  • a pseudo white LED or RGB-LED is more preferable.
  • a third aspect of the present invention is a rod-shaped illumination device having a point light source and a light guide that has a columnar shape and has an outer diameter force that decreases from both end faces toward the center. Then, both end forces of the light guide are provided.
  • a rod-shaped illuminating device that allows the light from the point light source to enter and emits the incident light from the side wall of the light guide.
  • the light guide includes a set of light guides having a shape that decreases in outer diameter force from one end face toward the other end face. It is preferable that the outer diameters of the light guides are small and the end surfaces are in close contact with each other.
  • a transparent light source having a rectangular light emission surface and having a parallel groove parallel to one side of the rectangular light emission surface is formed in the center of the back surface located on the opposite side of the rectangular light emission surface.
  • the light guide body has an outer shape substantially the same shape as the parallel groove of the light guide plate, and is disposed in the parallel groove.
  • side surfaces of the light guide there are side surfaces other than the side surfaces facing the side walls forming the parallel grooves of the light guide plate, and the side surfaces are flat so that light is reflected. It may be formed on a curved surface, and it is preferable that a prism row is formed on the side surface.
  • the cross-sectional shape perpendicular to the axial direction of the light guide body is a triangular shape, a circular shape, a shape obtained by cutting a part of an ellipse, or a shape of a part of a parabola.
  • a light guide for guiding the light emitted from the point light source to the end face of the light guide.
  • the point light source is more preferably a pseudo white LED or RGB-LED, which is preferably an LED.
  • the RGB-LED preferably lights up sequentially.
  • a fourth aspect of the present invention is a planar illumination device, the rod-shaped illumination device according to the third aspect of the present invention, a rectangular light exit surface, and one side of the rectangular light exit surface, A plurality of transparent light guide plates each having an inclined back surface that is inclined with respect to the rectangular light exit surface so that the plate thickness is reduced by applying force to the opposite side facing the one side;
  • the light guide plate is arranged such that the rectangular light exit surfaces form the same plane, the side surface including the one side is in contact with the side surface including the opposite side, and the inclined back surface and the side surface including the one side
  • the present invention provides a planar illumination device in which a light guide body of the rod-shaped illumination device is disposed in a formed space.
  • a fifth aspect of the present invention is a transparent light guide plate, which is positioned on the opposite side of the light emitting surface, and is parallel to one side of the light emitting surface.
  • a light guide plate having a shape in which the groove depth gradually increases and the groove width gradually increases from both end faces toward the center. is there.
  • a sixth aspect of the present invention is a transparent light guide plate, which is positioned on the opposite side of the light emitting surface with a rectangular shape and parallel to one side of the light emitting surface.
  • a light guide plate having a shape in which the groove depth gradually increases and the groove width gradually increases from one end face to the other end face. To do.
  • the back surface located on both sides of the groove is inclined with respect to the light emitting surface.
  • a seventh aspect of the present invention is a planar illumination device, which is emitted from the light guide plate according to the fifth or sixth aspect of the present invention, a point light source, and the point light source.
  • the planar lighting device has an additional light guide member for guiding the light to the portion of the end face of the light guide plate where the groove is formed.
  • an eighth aspect of the present invention is a transparent light guide plate having a rectangular light emission surface and a plate thickness from one side of the rectangular light emission surface toward the opposite side facing the one side. It will be thinner
  • an inclined back surface that is inclined with respect to the rectangular light exit surface, a side surface including the one side, a light incident surface that is perpendicular to the one side, and light incident on the inside from the light incident surface are:
  • a light guide plate having a light incident portion including an inclined surface that is reflected on a side surface including the opposite side is provided.
  • the light incident surfaces of the light incident portions are formed on both end faces perpendicular to the one side of the light guide plate, and the light incident portions It is preferable that the inclined surface is inclined toward the center from the both end surfaces.
  • the light incident surface of the light incident portion is formed on one end surface of two end surfaces perpendicular to the one side of the light guide plate, and the inclined surface of the light incident portion is the one side. It is preferable that it is inclined as it goes to the other end surface.
  • a ninth aspect of the present invention is a planar illumination device, comprising the light guide plate according to the seventh aspect of the present invention and a point light source, wherein the light from the point light source is A planar illumination device for irradiating the light incident surface of the light guide plate is provided.
  • the light guide member of the first aspect of the present invention can guide light into the inside by the second light guide and also emit light with the light emission surface force of the first light guide.
  • a point light source such as a light emitting diode (LE D) can be used, and the thickness can be reduced.
  • the outer shape of the second light guide can be processed into a shape that matches the shape of the parallel grooves of the first light guide, the uneven brightness of the parallel grooves of the first light guide is suppressed. If the outer shape of the second light guide is processed into the shape corresponding to the shape, the occurrence of uneven brightness can be reduced, and a thin light guide member can be obtained.
  • the shape of the parallel grooves of the first light guide and the outer shape of the second light guide can be freely designed in order to suppress the bright lines on the light exit surface of the first light guide.
  • a light guide member is most suitable as a light guide member used for a backlight unit of a liquid crystal panel.
  • planar illumination device uses a point light source such as a light-emitting diode capable of adjusting the used wavelength of the light source without using a cold cathode tube as the illumination light source. Therefore, it is possible to expand the color reproduction range where the color reproducibility is high and to improve the saturation.
  • a point light source such as a light-emitting diode capable of adjusting the used wavelength of the light source without using a cold cathode tube as the illumination light source. Therefore, it is possible to expand the color reproduction range where the color reproducibility is high and to improve the saturation.
  • the rod-shaped illuminating device of the third aspect of the present invention includes a double-sided force LED of a columnar light guide and the like. Since the light from the point light source can be incident and the incident light can be emitted also with the side wall force, it can be used instead of the cold cathode tube of the planar illumination device.
  • the shape of the light guide can be processed into a desired shape, it is optimal as a light source for a planar illumination device having a thin light guide plate.
  • a pseudo-white LED or RGB-LED can be used as the point light source, it is possible to expand the color reproduction range with high color reproducibility and improve the saturation.
  • the planar illuminating device uses a so-called tandem light guide plate as the light guide plate, and uses both end faces of the columnar light guide without using a cold cathode tube as the illumination light source. Since the rod-shaped illumination device according to the third aspect of the present invention in which the light of a point light source such as LED is incident and the incident light is emitted from the side wall is used, a color gamut with high color reproducibility is used. In addition to being able to increase magnification and saturation, it is also possible to reduce the thickness and weight.
  • a groove parallel to one side of the light emission surface is formed in a substantially central portion of the back surface opposite to the rectangular light emission surface. Because of the configuration, it is possible to realize a reduction in thickness and weight without having to provide a region for arranging the light source on the lower surface of the light guide plate.
  • a point light source such as an LED can be used as the light source, and the light from the point light source that is also incident on the end face force of the light guide plate is grooved. Since the light can be emitted from the rectangular light exit surface after being reflected by the wall surface constituting the light, the light utilization efficiency can be increased.
  • Such a light guide plate is also optimal as a light guide plate used in a knock light unit of a liquid crystal panel.
  • planar lighting device includes the light guide plate according to the fifth or sixth aspect of the present invention, the light use efficiency is improved, and a reduction in thickness and weight is realized.
  • a point light source such as an LED can be used, the color gamut can be expanded and the saturation can be improved.
  • the light guide plate of the eighth aspect of the present invention includes a light incident surface perpendicular to the one side including a side of the rectangular light exit surface, and light incident on the inside from the light incident surface. Is provided with a light incident part that includes an inclined surface that reflects to the side surface including the opposite side facing one side, so that the light from the point light source incident on the inside of the light guide plate is also emitted as a rectangular light. It can be projected efficiently from the surface.
  • a light guide plate does not need to be provided with a region for arranging a linear light source, and thus can be made thinner and lighter.
  • Such a light guide plate is also a liquid Ideal as a light guide plate used in crystal panel knocklight units.
  • planar lighting device of the ninth aspect of the present invention includes the light guide plate of the eighth aspect of the present invention, the apparatus can be made thinner and lighter, and Since a point light source such as an LED can be used, it is possible to expand the color gamut and improve the saturation with high color reproducibility.
  • FIG. 1A is a schematic perspective view of a liquid crystal display device using the planar illumination device of the present invention
  • FIG. 1B is a schematic cross-sectional view thereof.
  • FIG. 2A and FIG. 2B are a schematic perspective view and a schematic side view, respectively, of a rod-shaped lighting device according to the present invention.
  • FIG. 3 is a partial enlarged cross-sectional view of the lower surface of the light guide, showing a state of the prism formed on the lower surface of the light guide.
  • FIG. 4 is a diagram schematically showing how the light of an LED is guided to a light guide using a light guide.
  • FIG. 5 is a structural example of a light guide having a circular cross section perpendicular to the length direction and narrowing from the end toward the center.
  • FIG. 6A is a schematic cross-sectional view showing a state in which the light guide is housed in a light guide plate having a shape in which the cross-sectional shape of the parallel grooves is such that a part of an ellipse is removed.
  • FIG. 6A is a schematic cross-sectional view showing a state in which the light guide is housed in a light guide plate having a shape in which the cross-sectional shape of the parallel grooves is such that a part of an ellipse is removed.
  • FIGS. 7A to 7C are configuration examples of a light guide used in a bar-type lighting device of a type in which one end face force light is incident.
  • FIG. 7A has a cross-sectional shape perpendicular to the length direction.
  • Fig. 7B is a light guide when the cross-sectional shape perpendicular to the length direction is removed from a part of an ellipse, and
  • Fig. 7C is a length of the light guide. This is a light guide when the cross-sectional shape perpendicular to the direction is circular.
  • FIG. 8 is a schematic diagram showing a state in which the light guide is housed in the parallel groove of the light guide plate in which the linear shape of the portion corresponding to the wall surface defining the parallel groove is a part of a hyperbola. It is sectional drawing.
  • FIG. 9 shows a guide in which the cross-sectional shape of the parallel grooves is formed by partial forces of two circular arcs that are symmetrical with respect to the center line that passes through the center of the parallel grooves and is perpendicular to the light exit surface of the light guide plate.
  • Outline of light plate It is sectional drawing.
  • FIG. 10 shows that the cross-sectional shape of the parallel grooves is formed by partial force of two parabolas symmetrical with respect to the center line perpendicular to the light exit surface of the light guide plate through the center of the parallel grooves. It is a schematic sectional drawing of an optical plate.
  • FIG. 11 is a schematic cross-sectional view of a light guide plate in which a cross-sectional shape perpendicular to the length direction of the parallel grooves is formed with two curvilinear forces convex toward the center of the parallel grooves.
  • FIG. 12 is a schematic view of a light guide plate in which a cross-sectional shape perpendicular to the length direction of the parallel grooves is formed by a curved force combining a convex curve and a concave curve directed toward the center of the parallel grooves.
  • FIG. 13 is an example of a halftone dot pattern formed on the light exit surface side of the light guide plate.
  • FIG. 14 is a schematic cross-sectional view of a planar illumination device using a plurality of light guide plates arranged in parallel.
  • FIG. 15A is a schematic cross-sectional view showing a state in which a prism sheet is arranged between the inclined back surface of the light guide plate used in the planar lighting device of the invention and the reflection sheet
  • FIG. 15B is a reflection sheet
  • FIG. 2 is a schematic plan view of the prism sheet disposed between the light guide plate and the inclined rear surface of the light guide plate, and a schematic cross-sectional view of the prism sheet.
  • FIG. 16A is a configuration example in which a reflector is disposed on the side surface of the light guide plate
  • FIG. 16B is a configuration example in which a reflector plate is disposed on the side surface of the light guide plate when the light guide plates are disposed in parallel. It is.
  • FIG. 17A is a schematic cross-sectional view of a light guide plate used in a planar lighting device of a type in which light is incident on the light guide plate using an optical fiber.
  • FIG. It is the typical bottom view seen from.
  • FIG. 18A is a schematic cross-sectional view of a light guide plate in which a rod-shaped light guide (second light guide) is integrated in a parallel groove, and FIG. 18B shows the light guide plate on the back side. It is the typical bottom view seen from.
  • FIG. 19 is a schematic perspective view of the light guide shown in FIGS. 18A and 18B.
  • FIG. 20A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove shaped such that a part of an ellipse is removed from a cross section perpendicular to the length direction.
  • FIG. 4 is a schematic bottom view of the light guide plate as viewed from the back side.
  • FIG. 21 is a schematic perspective view of the light guide shown in FIGS. 20A and 20B.
  • FIG. 22A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a triangular cross section perpendicular to the length direction, and FIG. 22B shows the light guide plate on the back side. It is the typical bottom view seen from.
  • FIG. 23 is a schematic perspective view of a light guide used in the light guide plate shown in FIGS. 22A and 22B when light is incident only from one end face.
  • FIG. 24A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a cross section perpendicular to the length direction in which a part of an ellipse is removed.
  • 24B is a schematic bottom view of the light guide plate shown in FIG. 24A as viewed from the back side.
  • FIG. 25 is a schematic perspective view of a light guide that is accommodated in the parallel grooves of the light guide plate shown in FIGS. 24A and 24B and allows light to enter only from one end face.
  • FIG. 26A shows a surface illumination of a type in which the end face force light of the light guide plate is incident without providing the light guide (second light guide) in the parallel groove of the light guide plate (first light guide).
  • 26B is a schematic cross-sectional view of the light guide plate used in the apparatus
  • FIG. 26B is a view taken along the line B-B of the light guide plate in FIG. 26A
  • FIG. 26C is a view of the rear side force of the light guide plate shown in FIG. It is the typical bottom view.
  • FIGS. 27A to 27C are other examples of the light guide plate used in the planar lighting device that does not have the second light guide
  • FIG. 27A is a cross-sectional shape in which a part of the ellipse is removed.
  • FIG. 27B is a schematic cross-sectional view of the light guide plate formed on the back surface with a groove having a groove
  • FIG. 27B is a view taken along the line B-B of the light guide plate shown in FIG. 27A
  • FIG. It is the typical bottom view which looked at the light guide plate seen from the back side.
  • FIG. 28A is a schematic cross-sectional view of a light guide plate used in a planar lighting device of a type in which one end surface force light is incident, and the groove has a V-shaped cross-section
  • FIG. 28C is a schematic bottom view of the light guide plate shown in FIG. 28A as viewed from the back side.
  • FIG. 29A is a schematic cross-section of a U-shaped light guide plate used in a planar lighting device of the type in which one end face force light is incident and the cross-sectional shape of the groove is a part of an ellipse cut.
  • 29B is a BB line arrow view of the light guide plate shown in FIG. 29A
  • FIG. 29C is a schematic bottom view of the light guide plate shown in FIG. 29A viewed from the back side.
  • FIG. 30A is a schematic cross-sectional view of a light guide plate of a tandem planar lighting device provided with the rod-shaped lighting device of the present invention
  • FIG. 30B is a partially enlarged cross-sectional view thereof
  • FIG. FIG. 3 is a schematic bottom view of the light guide plate shown in OB as seen from the back side with the reflective film removed.
  • FIG. 31A is a schematic cross-sectional view of a plurality of light guide plates arranged in tandem, which is used in a tandem planar lighting device having a light guide body having the shape shown in FIG. 5, and FIG. FIG. 31C is a partial enlarged cross-sectional view, and FIG. 31C is a schematic bottom view of the light guide plate shown in FIG. 31B as viewed from the back side with the reflection film removed.
  • FIG. 32A is a schematic cross-sectional view of a plurality of light guide plates arranged in tandem, in which light is incident from one end portion, and FIG. 32B is a partially enlarged cross-sectional view thereof.
  • 32C is a schematic bottom view of the light guide plate shown in FIG. 32B viewed from the back side with the reflection film removed.
  • FIG. 33A is a schematic cross-sectional view of a configuration example different from FIGS. 32A to 32C of a plurality of light guide plates arranged in tandem, in which light from one end portion is incident, 33B is a partially enlarged cross-sectional view, and FIG. 33C is a schematic bottom view of the light guide plate shown in FIG. 33B as viewed from the back side with the reflection film removed.
  • FIG. 34A is a schematic cross-sectional view of a plurality of tandem light guide plates used in a planar illumination device that does not use a rod-like illumination device
  • FIG. 34B is a partially enlarged cross-sectional view thereof
  • FIG. 34C is a schematic bottom view of the light guide plate shown in FIG.
  • FIG. 35A is a schematic cross-sectional view of a configuration example different from FIGS. 34A to 34C of a plurality of light guide plates arranged in tandem used in a planar lighting device that does not use a rod-like lighting device.
  • FIG. 35B is a partially enlarged cross-sectional view thereof
  • FIG. 35C is a schematic bottom view of the light guide plate shown in FIG. 35B as viewed from the back side.
  • FIG. 1A shows a liquid crystal using the planar illumination device of the present invention (hereinafter also referred to as a knock light unit).
  • the schematic perspective view of a display apparatus is shown.
  • the liquid crystal display device 10 basically includes a planar illumination device 2 of the present invention, a liquid crystal display panel 4 disposed on the light emission surface side of the planar illumination device 2, and a drive unit 6 that drives them.
  • Have Fig. 1B shows a schematic cross-sectional view of the backlight unit.
  • the planar illumination device 2 of the present invention is used as a backlight unit of the liquid crystal display device 10, and the planar illumination device for irradiating the entire surface of the liquid crystal display panel 4 with uniform light from behind the liquid crystal display panel 4.
  • the planar illumination device 2 basically includes a rod-shaped illumination device 12, a diffusion sheet 14, prism sheets 16 and 17, a light guide plate 18, a reflector 20, and a reflection plate 22.
  • FIG. 2A and FIG. 2B show a schematic perspective view and a schematic side view of the rod-shaped lighting device 12 according to the present invention, respectively.
  • the rod-shaped lighting device 12 mainly includes a light guide 32 and a pair of light emitting diodes (LEDs) 34A and 34B as point light sources.
  • 2A and 2B is used for the light guide plate 18 having a triangular cross section of the parallel groove 18f as shown in FIGS. 1A and 1B, and the light guide plate in FIGS. 2A and 2B.
  • Each of the bodies 32 has an outer shape of a triangular prism that is accommodated in the parallel groove 18f of the light guide plate 18.
  • the light guide 32 used in the rod-shaped illuminating device 12 of the present invention has a cross-sectional shape that is substantially the same as the cross-sectional shape of the parallel grooves 18f of the light guide plate 18 when cut along a plane perpendicular to the length direction thereof. It has a similar triangular shape.
  • Each light guide 32 is formed such that the cross-sectional area gradually decreases from the both end faces 33a toward the center.
  • the surface on the side that does not face the light guide plate 18, that is, the lower surface 33b of the light guide 32 is inclined only.
  • a light guide 32 is formed.
  • the light guide 32 is configured using a pair of transparent bodies 33A and 33B.
  • Each of the transparent bodies 33A and 33B has a triangular cross section, and has a shape such that the cross-sectional area gradually decreases from one end face 33a toward the other end face 33b.
  • the light guide 32 is configured by coaxially connecting the end faces 33b on the side having a smaller cross-sectional area of each of the transparent bodies 33A and 33B so as to be in close contact with each other.
  • the LEDs 34A and 34B are respectively disposed on both end surfaces 33a of the light guide 32 as shown in FIGS. 2A and 2B.
  • the LEDs 34A and 34B are connected to the drive boot 6.
  • Light from the LEDs 34A and 34B is incident on the inside from the end faces 33a of the light guides 32A and 32B, respectively.
  • the lower surface 33b of the light guide 32 is inclined, so that a partial force of light incident from both end surfaces 33a of the light guide 32 is reflected by the lower surface 33b and directed upward in FIG. 2B.
  • the light is emitted from the side wall surface of the light guide 32 to the outside.
  • FIG. 3 partially shows a state in which the prisms 36 are formed in a row on the lower surface 33 b of the light guide 32.
  • the prism 36 is formed to extend perpendicular to the length direction of the light guide 32.
  • Each shape of the prism 36 can be any shape, and is preferably a prism having an apex angle force of 5 °.
  • a prism with an apex angle force of 5 ° when the collimated light beam is also incident on the end face force of the light guide 32, the collimated light beam is incident on the slope of the prism and is almost vertical when totally reflected. Therefore, the light quantity distribution of the light emitted from the side surface of the light guide 32 in the entire length direction of the light guide can be made more uniform.
  • the light guide 32 can be formed of a transparent resin.
  • a production method for example, a method of molding heated raw material resin by extrusion molding or injection molding, a casting polymerization method in which a monomer, an oligomer, or the like is polymerized and molded in a mold can be used.
  • the material of the light guide 18 include acrylic resin such as polycarbonate and PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), and PMMA (polymethylolene).
  • Tatalylate benzenoremetatalylate
  • MS resin other acrylic resins
  • transparent resins such as COP (cycloolefin polymer)
  • Transparent resin is mixed with fine particles to scatter light. The light emission efficiency from the side wall can be further increased.
  • the light guide 32 is composed of two transparent bodies 33A and 33B, but the light guide may be integrally formed.
  • the transparent body may be processed so that the cross-sectional area decreases from one end toward the center.
  • the shape with a smaller cross-sectional area as it goes from one end to the other end is easier to process, so two transparent bodies having such a shape are Combining the light guides together has the advantage that the manufacturing cost can be kept low.
  • the light emitting diode (LED) 34A constituting the rod-shaped lighting device 12 of the present invention can be configured using, for example, a high-intensity LED, such as an RGB-LED or a white LED. It is preferable to use it. In addition to these, incandescent and miniature bulbs can also be used.
  • RGB-LEDs When RGB-LEDs are used as the LEDs 34A and 34B, it is preferable to sequentially turn on the RGB pulses. By turning on pulses in this way, power consumption can be reduced. In this way, when R, G, and B of the RGB-LEDs are turned on sequentially, it is preferable to turn them on sequentially with AC (alternating current) lighting of several milliseconds or less. For example, these lights appear to the human eye in the same way as when the lights from the R, G, and B LEDs are integrated and lit by direct current because of their responsiveness.
  • AC alternating current
  • the LCD panel does not require an RGB filter, so the brightness is improved by a factor of about 2 compared to the case with a filter. be able to.
  • the LEDs 34A and 34B are arranged at one end as shown in FIG.
  • the light that is also emitted from the LEDs 34A and 34B may be guided to the end face of the light guide 32 using the light guides 38A and 38B.
  • the light guides arranged in the parallel grooves of the respective light guide plates are arranged.
  • Light guides, which are additional light guide members, between the end portions and the light emitting portions of the LEDs corresponding to the respective light guides 38 may be arranged so that the light of the LED enters the end of the light guide through the light guide.
  • Such a light guide 38 can be configured by combining an optical fiber and a rectangular light guide, for example. If the LED 34 is disposed near the end face of the light guide 32, the light guide 32 may be deformed or melted by the heat generated by the LED 34. By using such a light guide 38, the LED 34 generates heat. It is possible to prevent the light guide 32 from being deformed and melted by the above.
  • the rectangular light guide can be configured using a transparent resin material in the same manner as the transparent body described above.
  • what uses an optical fiber is illustrated as an example of the light guide which is this additional light guide member.
  • the light guide of the rod-shaped illumination device of the present invention is accommodated and used in the parallel groove of the light guide plate of the planar illumination device.
  • a typical cold cathode tube has a cylindrical shape, so that light emitted from the cold cathode tube can be reliably and efficiently emitted from the light guide plate.
  • the cold cathode tube had to be securely housed in the parallel groove. For this reason, it has been difficult to make the light guide plate thin.
  • the planar illumination device of the present invention the light guide body of the rod-like illumination device is processed so that it has substantially the same outer shape as the parallel groove of the light guide plate. The entire planar lighting device can be made thin without relying on it.
  • the shape of the parallel groove of the light guide plate By changing, generation of bright lines immediately above the parallel grooves can be suppressed. Therefore, by processing the outer shape of the light guide 32 of the rod-like lighting device 12 in accordance with the shape of the parallel grooves 18f of the light guide plate 18, the generation of bright lines on the light exit surface 18a of the light guide plate 18 is suppressed. Thus, it is possible to configure a planar illumination device that is thinner than when a conventional cold cathode tube is used.
  • Fig. 5 shows an example of a light guide having a circular cross section perpendicular to the length direction and narrowing from the end toward the center.
  • the light guide 52 shown in FIG. 5 is configured by connecting a pair of transparent frustoconical transparent bodies 53A and 53B so that the end faces with small cross sections are in close contact with each other.
  • Such a light guide 52 has, for example, a semicircular cross section perpendicular to the length direction. It is used for a light guide plate having a parallel groove.
  • the light guide having the shape shown in FIG. 5 converts a point light source typified by an LED or the like into a rod light source by the rod light guide, and the rod light guide is placed in a recess of the flat light guide. By embedding, it becomes possible to convert the bar-shaped illumination into a planar illumination and use it as a liquid crystal knock light unit.
  • FIGS. 6A to 6C show further different configuration examples of the light guide of the rod-shaped lighting device.
  • FIG. 6A is a schematic cross-sectional view showing a state in which the light guide 62 is accommodated in the light guide plate 18 having a shape in which the cross-sectional shape of the parallel groove 18f is a part of the ellipse is removed.
  • FIG. FIG. 6C is a schematic perspective view of the light guide 62.
  • the light guide 62 has a shape in which a cross-sectional shape perpendicular to the length direction is obtained by removing a part of an ellipse.
  • the light guide 62 also includes two transparent bodies 63A and 63B force.
  • the transparent bodies 63A and 63B have such a shape that is obtained by cutting the elliptic cylinder at a plane having a predetermined angle with respect to the central axis and perpendicular to the long axis of the ellipse.
  • the light guide body 62 is configured by connecting the end faces having the smaller cross-sectional areas of the transparent bodies 63A and 63B. As shown in FIG. 6A, the light guide 62 having such a shape is accommodated in the parallel groove 18f of the light guide plate 18 in which the cross-sectional shape of the parallel groove 18f is formed as a part of an ellipse. Used. Then, as shown in FIG.
  • the reflector 22 is disposed below the inclined surface of the light guide plate 18, and the reflector 20 is disposed so as to close the parallel groove 18f in a state where the light guide 62 is accommodated in the parallel groove 18f. Is done.
  • a prism can be formed on the lower surface.
  • the light guide having the shape shown in FIGS. 6A to 6C converts a point light source typified by an LED into a linear light source by using a rod-shaped light guide. It can be used as an alternative light source for CCFL (Cold Cathode Fluorescent Lamp) used as a linear light source.
  • CCFL Cold Cathode Fluorescent Lamp
  • the light guides shown in FIG. 5 and FIGS. 6A to 6C may be configured as an integral force formed by connecting two transparent bodies.
  • the present invention is not limited to this.
  • bar lighting The shape of the light guide constituting the device is not limited to the above example, and can be changed to various shapes according to the shape of the parallel grooves of the light guide plate which constitutes the planar illumination device described later.
  • an LED light source if a single LED light source can secure a sufficient amount of light, an LED light source is arranged only on one end surface of the light guide 32, and the light from the LED light source is configured to be incident only on that end surface. Also good.
  • the light guide 32 is configured by combining two transparent bodies, a single transparent member having a shape capable of irradiating light substantially uniformly in the parallel groove of the light guide plate is used. If configured, ...
  • FIGS. 7A, 7B, and 7C examples of the configuration of the rod-shaped illumination device that makes the light of one end surface force LED light source of the light guide formed using one transparent member incident are shown in FIGS. 7A, 7B, and 7C, respectively.
  • FIGS. 7A, 7B, and 7C examples of the configuration of the rod-shaped illumination device that makes the light of one end surface force LED light source of the light guide formed using one transparent member incident are shown in FIGS. 7A, 7B, and 7C, respectively.
  • FIGS. 7A, 7B, and 7C examples of the configuration of the rod-shaped illumination device that makes the light of one end surface force LED light source of the light guide formed using one transparent member incident are shown in FIGS. 7A, 7B, and 7C, respectively.
  • the left side of the drawing is a schematic side view of the light guide
  • the right side of the drawing is a schematic view of a cross section perpendicular to the length direction of the light guide.
  • the light guide 74 of the rod-shaped illumination device shown in FIG. 7A has a triangular cross-sectional shape in a direction perpendicular to the length direction, and one end face (referred to as a large-diameter side end face) on which light from the LED 34 enters 74
  • the cross-sectional area gradually decreases from b toward the other end face (referred to as the end face on the small diameter side) 74c.
  • the lower surface 74a of the light guide 74 is formed so as to incline upward from the large diameter side end surface 74b of the light guide 74 toward the small diameter side end surface 74c.
  • a prism row is formed on the lower surface 74 a of the light guide 74.
  • the light from the LED 34 incident from the large-diameter end surface 74b of the light guide 74 is reflected by the prism row on the lower surface 74a, and then the side force of the light guide 74 is external. To exit.
  • the light guide 76 of the rod-shaped illuminating device shown in FIG. 7B has a shape in which a cross-sectional shape in a direction perpendicular to the length direction is a part of an ellipse, and LED light is emitted from the light guide 76.
  • the cross-sectional area gradually decreases from the incident large-diameter side end surface 76b toward the small-diameter side end surface 76c.
  • Such a light guide 76 can be obtained, for example, by cutting a transparent elliptic cylinder at a predetermined angle with respect to its central axis and a plane perpendicular to the major axis of the ellipse. . Even in the light guide 76 having such a structure, a prism row can be formed on the lower surface 76a.
  • the light guide 78 of the rod-shaped lighting device shown in FIG. 7C has a direction perpendicular to the length direction.
  • the cross-sectional shape is circular, and the shape gradually becomes thinner from the large-diameter side end surface 78b on which the LED light is incident toward the other small-diameter side end surface 78c. That is, the light guide of the rod-shaped lighting device shown in the figure has an elongated truncated cone shape (cone shape). Even when the light guide 78 having such a structure is used, the LED light incident from the large-diameter end face 78b can be emitted from the side face of the light guide 78.
  • the light guide of the rod-like illumination device that makes the light of the LED light source incident from one end face has been described.
  • the shape of such a light guide is not limited to the above shape, and the light guide If the incident light can be emitted from the side surface of the light guide, it can be formed into an arbitrary shape.
  • the light guide plate 18 will be described. As shown in FIG. 1B, the light guide plate 18 is formed in parallel to the one side on both sides of the rectangular light emitting surface 18a, a pair of thick portions 18b parallel to one side thereof, and the thick portion 18b.
  • the thin-walled end 18c and the thick-walled portion 18b are thinned toward the thin-walled end portions 18c on both sides in the direction perpendicular to the one side, and the inclined back-surface portion 18e and the thick-walled portion are formed.
  • 18 b has a parallel groove 18 f formed in parallel to the one side for accommodating the light guide 32. That is, the light guide plate 18 is a plate-like member having a rectangular outer shape on the surface, and is formed of a transparent resin.
  • the light exit surface 18a of the light guide plate 18 is flat, and the surface on the opposite side is inclined with respect to the light exit surface 18a so that the plate thickness becomes thinner toward the one side.
  • the light guide plate 18 has a pair of inclined back surfaces 18d including the central axis of the parallel grooves 18f and symmetric with respect to a plane perpendicular to the light exit surface 18a.
  • the oblique rear surfaces 18d are inclined with respect to the light exit surface 18a so that the thickness decreases toward the thin end portions 18c on both sides.
  • 1A and 1B corresponds to the first light guide of the light guide member according to the present invention, and the light guide housed in the parallel groove of the light guide plate of the light guide member according to the present invention. Corresponds to the second light guide.
  • the light guide plate 18 having the structure shown in FIG. 1B, out of the light emitted from the light guide arranged in the parallel groove 18f, the light whose wall force of the parallel groove 18f is also incident on the inside of the light guide plate 18 is After being reflected by the back surface 18d of the light guide plate 18, it is emitted from the light exit surface 18a. At this time, some light may leak from the inclined back surface 18d of the light guide plate 18. However, the leaked light is reflected by the reflection sheet 18 formed on the inclined back surface 18d side of the light guide plate 18. The light again enters the light guide plate 18 and exits from the light exit surface 18a.
  • the light guide plate 18 is formed by, for example, a method in which heated raw material resin is molded by extrusion molding or injection molding, a casting polymerization method in which monomers, oligomers, and the like are molded in a mold. Can be used.
  • the material of the light guide plate 18 include acrylic resin such as polycarbonate and PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), PMMA (polymethyl). Metatalylate), benzyl metatalylate, MS resin, other acrylic resins, or transparent resins such as COP (cycloolefin polymer) can be used.
  • the transparent resin may be mixed with fine particles for scattering light, whereby the light emission efficiency from the light exit surface can be further increased.
  • the cross-sectional shape of the parallel groove is a partial line corresponding to the wall surface of the light guide plate that defines the parallel groove when the parallel groove is cut along a plane perpendicular to its length direction. And a shape formed by a straight line connecting both ends of the partial line.
  • a cross section obtained by cutting a parallel groove along a plane perpendicular to its length direction is simply referred to as a cross section of a parallel groove.
  • the parallel grooves 18f of the light guide plate 18 in FIGS. 1A and 1B are formed so that the cross-sectional shape thereof is a triangular shape.
  • the force of the parallel groove 18f is triangular.
  • the cross-sectional shape of the parallel groove 18f is symmetric with respect to the center line perpendicular to the light emission surface of the light guide plate 18f through the deepest part or center of the parallel groove 18f, and the light emission surface 18a. Any shape can be used as long as it becomes thinner. For example, as shown in FIG. 8 and FIGS.
  • the parallel groove 18f when the parallel groove 18f is cut along a plane perpendicular to its length direction, it corresponds to the wall surface of the light guide plate 18 that defines the parallel groove 18f.
  • the line shape of the portion to be formed can be a shape of a part of a hyperbola or a part of an ellipse.
  • the line shape corresponding to the wall surface of the light guide plate that defines the parallel grooves may be a suspended line shape.
  • the parallel groove in the cross section of the parallel groove, when the line shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f is a part of a hyperbola, the parallel groove
  • the cross section of the light guide 72 accommodated in the 18f can also be processed into a shape substantially the same as the cross section of the parallel groove 18f. That is, in the cross section of the light guide 72, the side wall of the light guide 72 is formed so that the linear shape of the portion corresponding to the side surface of the light guide 72 becomes a part of a hyperbola.
  • the parallel groove can be formed in such a shape that a portion corresponding to the deepest portion of the parallel groove becomes a cusp in the cross section of the parallel groove. That is, in the cross section of the parallel groove, the line shape of the portion corresponding to the deepest portion of the parallel groove has one sharp intersection that intersects each other, and is perpendicular to the light exit surface of the light guide plate through the center of the parallel groove. It is also possible to create partial forces that are two curves or straight lines that are symmetrical about the centerline. In the present invention, even if the cross-sectional shape of the parallel groove of the light guide plate is any of the above shapes, the light exit surface force of the light guide plate can be emitted uniformly.
  • the line shape of the portion corresponding to the wall surface of the light guide plate that defines the parallel groove has one sharp intersection that intersects each other, and the center of the parallel groove 18f
  • An example is shown in which the partial force of two curves symmetric with respect to the center line perpendicular to the light exit surface of the light guide plate is shown.
  • the light guide plate 50 shown in FIG. 9 is a case where two curves 54a and 54b symmetric with respect to the center line X passing through the center of the parallel groove and perpendicular to the light exit surface 50a of the light guide plate 50 are arcs. In this case, as shown in FIG.
  • the center position of the arc 54a corresponding to one side wall forming the parallel groove 18f is different from the center position of the arc 54b corresponding to the other side wall. .
  • the portion 56 where the arc-shaped side walls meet has a sharp shape as shown in FIG.
  • the side wall of the light guide 57 accommodated in the parallel groove 18f is shown in FIG. As shown, it can be processed in a shape corresponding to the shape of the parallel groove 18f.
  • the linear shape of the portion corresponding to the wall surface of the light guide plate that defines the parallel grooves in the cross section of the parallel grooves has one sharp intersection where they intersect each other.
  • Another example is shown in the case of partial force of two curves symmetric with respect to the center line perpendicular to the light exit surface of the light guide plate.
  • the light guide plate 60 shown in FIG. 10 is a case where two curves 64a and 64b which are symmetrical with respect to the center line X passing through the center of the parallel groove 18f and perpendicular to the light exit surface of the light guide plate are parabolas.
  • the side wall of the parallel groove 18f is formed so that the focal point of the parabola 64a that forms one side wall of the parallel groove 18f is different from the focal point of the parabola 64b that forms the other side wall 22b. .
  • the line shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f in the cross section of the parallel groove is formed from two curves 64a and 64b that intersect at an intersection 66.
  • the angle ⁇ between the tangent line at the intersection (point) 66 of the curve 64a corresponding to one side wall of the parallel groove 18f and the tangent line at the intersection point 64 of the curve 64b corresponding to the other side wall is 90 degrees or less is preferable, and 60 degrees or less is even more preferable.
  • FIGS. 11 the linear shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f in the cross section of the parallel groove is formed from two curves 73a and 73b that are convex toward the center of the parallel groove 18f.
  • FIG. 11 the linear shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f in the cross section of the parallel groove is formed from two curves 73a and 73b that are convex toward the center of the parallel groove 18f.
  • the line shape of the portion corresponding to the wall surface of the light guide plate that defines the parallel groove 18f in the cross section of the parallel groove is a convex curve that is directed toward the center of the parallel groove 18f.
  • This is an example of the light guide plate 80 in which a curved force combining 82a and 82b and concave curves 84a and 84b is also formed.
  • the light guide plates 70 and 80 having the parallel grooves having the cross-sectional shapes as shown in FIGS. 11 and 12 can also emit light with sufficient light emission surface strength while suppressing generation of bright lines.
  • the linear shape of the portion corresponding to the deepest part in the cross section of the parallel groove can be made convex or concave curved or linear by directing toward the center of the parallel groove, and combinations thereof. It may be.
  • These curves are not limited to the illustrated arc, but may be part of a curve such as an ellipse, parabola, or hyperbola that is convex or concave toward the center of the parallel grooves. That's fine.
  • the curve constituting the parallel groove is at the center of the parallel groove.
  • the curve is preferably a curve that can be approximated by a 10th-order function as long as it is part of a curved line such as a circle, ellipse, parabola, or hyperbola, convex or concave.
  • the light guide housed in the parallel groove of the light guide plate is not shown, but when the parallel groove of the light guide plate is changed to various shapes as shown in FIG.
  • the light guide housed in the parallel groove can also be processed into a shape corresponding to the shape of the parallel groove.
  • the density of the halftone dot is high at a certain center line X, and as it is directed toward both sides (perpendicular to the center line) from the center line X.
  • a halftone dot pattern 92 that gradually decreases the density of halftone dots may be formed on the light exit surface 18a of the light guide plate 18, for example, by printing.
  • a thin sheet on which the halftone dot pattern is formed may be laminated on the light emitting surface.
  • the shape of the halftone dots can be any shape, such as a rectangle, a circle, or an ellipse, and the density of the halftone dots can be appropriately selected according to the intensity and spread of the bright lines.
  • a portion corresponding to the halftone dot pattern may be roughened as a sanded surface. Such a rubbing surface may be formed at the deepest part or the side wall of the parallel groove of the light guide plate.
  • the cross-sectional shape of the wall surface portion constituting the parallel groove 18f of the light guide plate 18 is triangular (V-shaped), that is, directly above the light source 12, that is, The relative illuminance at the center of the rectangular light exit surface 18a is reduced.
  • the cross-sectional shape of such a parallel groove is a triangle
  • the apex (deepest part) of the parallel groove is flattened with a predetermined width or a curved surface having a relatively small radius of curvature, so that It is preferable to make the illuminance uniform.
  • the illuminance on the light exit surface of the light guide plate can be optimally adjusted and made uniform simply by designing the cross-sectional shape of the deepest portion of the parallel groove of the light guide plate to be the shape described above. it can.
  • the light guide body of the rod-shaped lighting device accommodated in the parallel groove is processed so as to have the same or similar shape as the above-described shape. Is desirable.
  • the cross-sectional shape at the portion of the symmetry plane s where the rear surfaces intersect is not only a chamfered flat shape or a rounded circular shape, but also an elliptical shape.
  • the intersecting portion is a sand rubbing surface, whereby the peak value of illuminance or luminance on the light exit surface can be reduced.
  • the peak value of the illuminance at the first portion of the light exit surface 18a of the light guide plate 18 is the light exit surface of the light guide plate 18.
  • the tip of the parallel groove 18f of the light guide plate 18 is tapered so that the average value of the illuminance of the second part 18a is 3 times or less, more preferably 2 times or less.
  • the peak value force of the illuminance of the first portion of the light exit surface 18a of the light guide plate 18 is set to be not more than three times the average value of the illuminance of the second portion of the light exit surface 18a of the light guide plate 18.
  • the shape of the light guide plate of the present invention has been described above.
  • the light guide plate having the above-described shape is connected to a plurality of light guide plates 18 such that end surfaces thereof are in close contact with each other, as shown in FIG.
  • it can be configured as a light guide member having a large light exit surface.
  • the light guides provided in the parallel grooves of a certain light guide plate 18 are arranged.
  • a part of the light emitted from the body 32 is reflected by the inclined surface inside the light guide plate 18 and then reaches the end surface of the light guide plate 18 and the end surface force of the adjacent light guide plate connected to the end surface Incident inside the adjacent light guide plate .
  • the light of the light guide force arranged on the adjacent light guide plate can also be used. Therefore, the light emission efficiency can be increased.
  • the inclination of the back surface of the light guide with respect to the light exit surface at the connection portion of the adjacent light guide plates becomes zero (0). It is possible to further suppress the occurrence of bright lines in the portion corresponding to the end surface of the light exit surface of the light guide plate, that is, the connecting portion.
  • planar illumination device having a large-sized light irradiation surface in which the light amount distribution of the light beam emitted from the light exit surface is uniform and the generation of bright lines is suppressed is obtained.
  • Such a planar illumination device having a large-size light irradiation surface can be applied to a liquid crystal display device having a large-size display screen, particularly for a wall-mounted liquid crystal display device such as a wall-mounted television. Is optimal.
  • the back surface of the light guide plate is formed as a flat surface.
  • a shape represented by a tenth order function may be used.
  • each coefficient of the tenth-order function may be determined so that light emitted from the light guide body accommodated in the parallel groove of the light guide plate is emitted from all of the one light guide plate. It may be determined that when light guide plates are connected, all light is emitted from a plurality of light guide plates.
  • Diffusion sheet 14 is made of, for example, PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), PMMA (polymethylol methacrylate), penzino methacrylate methacrylate, MS resin, other acrylic resins, Alternatively, it is formed by imparting light diffusibility to a flat plate member made of an optically transparent resin such as COP (cycloolefin polymer).
  • the method is not particularly limited.
  • the surface of the flat plate member is subjected to surface roughening by fine unevenness processing or polishing (hereinafter, the surface on which these are applied is referred to as “sand-rubbed surface”) to impart diffusibility.
  • pigments such as silica, titanium oxide, zinc oxide, etc. that scatter light on the surface, or beads such as resin glass, zirconium oxide, etc. can be applied together with a binder, It is formed by kneading the aforementioned pigment and beads that scatter light.
  • the diffusion sheet 14 a mat type or coating type diffusion sheet can be used as the diffusion sheet 14.
  • the diffusion sheet 14 it is also preferable to use a film-like member having a thickness of 500 ⁇ m or less that uses the above-mentioned material and imparts light diffusibility.
  • the diffusion sheet 14 is disposed at a predetermined distance from the light exit surface 18a of the light guide plate 18.
  • the distance depends on the light amount distribution from the light exit surface 18a of the light guide plate 18. Can be changed as appropriate.
  • the diffusion sheet 14 is separating the diffusion sheet 14 from the light exit surface 18a of the light guide plate 18 by a predetermined interval, light emitted from the light exit surface 18a of the light guide plate 18 is transmitted between the light exit surface 18a and the diffusion sheet 14. It is further mixed (mixed). Thereby, the illuminance of the light that passes through the diffusion sheet 14 and illuminates the liquid crystal display panel 4 can be made more uniform.
  • a method of separating the diffusion sheet 14 from the light exit surface 18a of the light guide plate 18 by a predetermined distance for example, a method of providing a spacer between the diffusion sheet 14 and the light guide plate 18 can be used.
  • the light exit surface 18a of the light guide plate 18 corresponding to the parallel groove 18f is obtained depending on the cross-sectional shape of the parallel grooves 18f of the light guide plate 18. It is not necessary to sufficiently reduce the peak value of illuminance at the same time, and a gap is provided between the diffusion sheet 14 and the light exit surface 18a of the light guide plate 18 to reduce the illumination light emitted from the diffusion sheet 14.
  • the illuminance distribution may be uniform.
  • the prism sheets 16 and 17 are transparent sheets formed by arranging a plurality of prisms in parallel, and improve the light condensing property of the light emitted from the light exit surface 18a of the light guide plate 18 to improve the brightness. can do.
  • One of the prism sheets 16 and 17 is arranged so that the extending direction of the prism row is parallel to the parallel groove 18f of the light guide plate 18, and the other is vertical. It is arranged so that. That is, the prism sheets 16 and 17 are arranged such that the extending directions of the prism rows are perpendicular to each other.
  • the prism sheet 16 is arranged so that the apex angle of the prism faces the light exit surface 18 a of the light guide plate 18.
  • the arrangement order of the prism sheets 16 and 17 is such that a prism sheet 16 having a prism extending in a direction parallel to the parallel groove of the light guide plate is arranged immediately above the light guide plate, and on the prism sheet 16, A prism sheet having prisms extending in a direction perpendicular to the parallel grooves 18f of the light guide plate 18 may be disposed, or vice versa.
  • a prism sheet is used instead of the prism sheet.
  • a sheet in which optical elements similar to prisms are regularly arranged may be used instead of the prism sheet.
  • a sheet that regularly includes optical elements such as a lens effect, such as a lenticular lens, a concave lens, a convex lens, and a pyramid type, can be used instead of the prism sheet.
  • FIGS. 15A and 15B it is preferable that a prism sheet 19 is also provided between the reflection sheet 22 and the inclined back surface 18d.
  • 15A is a schematic cross-sectional view showing a state in which the prism sheet 19 is disposed between the reflection sheet 22 and the inclined back surface 18d of the light guide plate 18.
  • FIG. 15B is an inclination of the reflection sheet 22 and the light guide plate 18.
  • FIG. 4 is a schematic plan view of the prism sheet 19 disposed between the back surface 18d and the light guide plate side, and a schematic cross-sectional view of the prism sheet 19.
  • the prism sheet 19 provided between the reflection sheet 22 and the inclined rear surface 18d of the light guide plate 18 is arranged so that the extending direction of the prism 19a is perpendicular to the parallel groove 18f of the light guide plate 18, and the prism 19 It is preferable to arrange so that the apex angle of 19a faces the inclined rear surface 18d of the light guide plate 18.
  • An optical element having a lens effect that may be an optical element having an effect similar to that of a prism sheet, such as an optical element such as a lenticular lens, a concave lens, a convex lens, or a pyramid type.
  • An optical element having an effect similar to that of a prism sheet such as an optical element such as a lenticular lens, a concave lens, a convex lens, or a pyramid type.
  • a sheet in which elements are regularly arranged may be provided.
  • the prism sheets 16 and 17, more preferably the prism sheet 19, are used.
  • the prism sheet 19 is unnecessary, and either one or both of the prism sheets 16 and 17 may not be used. Expensive prism By reducing the number of sheets used or stopping the use of prism sheets, the cost of the apparatus can be reduced.
  • the reflection sheet 22 is used to reflect light leaking from the back surface (the lower surface in the figure) of the light guide plate 18 and to make it incident on the light guide plate 18 again. Can be improved.
  • the reflection sheet 22 is formed so as to cover the lower surface (inclined surface) of the light guide plate 18.
  • the reflector 20 is provided behind the light guide 32 so as to close the parallel grooves 18 f of the light guide plate 18.
  • the reflector 20 reflects light from the lower surface of the light guide 32, and the side wall surface force of the parallel grooves 18 f of the light guide plate 18 can also make the light incident.
  • the reflection sheet 22 may be formed of any material as long as it can reflect light leaking from the back surface (the lower surface in the figure) of the light guide plate 18.
  • PET or PP A resin sheet in which voids are formed by kneading and stretching the filler in (polypropylene) and the like to increase the reflectance, a sheet having a mirror surface formed by aluminum vapor deposition on the surface of a transparent or white resin sheet as described above, It can be formed of a metal foil such as aluminum or a resin sheet carrying the metal foil, or a metal thin plate having sufficient reflectivity on the surface.
  • the reflector 20 can be formed of, for example, the same material as that of the reflection sheet, that is, a resin material, a metal foil, or a metal plate that gives the surface sufficient reflectivity.
  • FIG. 14 a mode has been described in which a plurality of independent light guide plates are connected to form a large light guide unit.
  • two or more guides are used. It is preferable to integrally mold the light plate.
  • a light guide unit when a light guide unit is configured by connecting a plurality of light guide plates, light is transmitted from the end surface portion of one light guide plate to the other light guide plate.
  • light scattering may occur at the end face.
  • Multiple light guide plates are integrated with each other In the light guide unit thus formed, such light scattering does not occur at the end face portion, so that it is possible to further increase the light use efficiency even with light source power.
  • a reflector 24 may be disposed on the side surface of the light guide plate 18 as shown in FIG. 16A. Further, as described above, when a plurality of light guide plates 18 are arranged, as shown in FIG. 16B, the reflector 24 should be arranged on the side surface of the light guide plate 18 arranged on the outermost side. By disposing such a reflection plate 24 on the side surface, light leakage from the side surface of the light guide plate 24 can be prevented, and the light utilization efficiency can be further enhanced.
  • the reflection plate 24 can be formed using the same material as the above-described reflection sheet and reflector. Further, in the above embodiment, the rod-like illumination device and the planar illumination device of the present invention are used for illuminating the liquid crystal display device, but can also be used as illumination devices such as ceiling illumination and wall illumination. .
  • FIG. 17A shows a schematic cross-sectional view of the light guide plate 18 constituting such a planar illumination device
  • FIG. 17B shows a schematic bottom view of the light guide plate 18 in which the back side force is also seen.
  • light guides 86 made of a transparent material are provided in contact with the respective wall surfaces (inclined surfaces) 18g constituting the parallel grooves 18f of the light guide plate 18.
  • the light guide 86 is a thin plate-like transparent body, and the surface 86a is formed in a curved surface shape.
  • FIG. 17A shows a schematic cross-sectional view of the light guide plate 18 constituting such a planar illumination device
  • FIG. 17B shows a schematic bottom view of the light guide plate 18 in which the back side force is also seen.
  • light guides 86 made of a transparent material are provided in contact with the respective wall surfaces (inclined surfaces) 18g constituting the parallel grooves 18f of the light guide plate 18.
  • the light guide 86 is a thin plate-like transparent body, and the surface
  • the light guide 86 is formed so that only the thickness gradually decreases with a constant width toward the center.
  • six optical fibers 88 are arranged on the end face 86b of the light guide 86, respectively.
  • the optical fiber 88 is connected to an LED (not shown).
  • the curved surface 86a of the light guide 86 is inclined with respect to the optical axis of light incident from the end face 86b of the light guide 86. is doing. Therefore, the light that has entered straight from the end face 86 b of the light guide 86 is reflected on the curved surface inside the light guide 86 and travels toward the inclined face 18 g of the parallel groove 18 f of the light guide plate 18. The light then enters the light guide plate 18 and is reflected by the inclined back surface 18d, and then exits from the light exit surface 18a.
  • the planar illumination device having such a structure is composed of a combination of a light guide that becomes a linear light source that sequentially raises incident light rays and a light guide that spreads the light rays emitted from the light guide force on a plane. Irradiation can be made more uniform.
  • FIG. 18A shows a schematic cross-sectional view of the light guide plate 18 in which the light guide 94 is incorporated in the parallel groove 18f
  • FIG. 18B shows a schematic bottom view of the light guide plate 18 viewed from the back side.
  • FIG. 19 shows a schematic perspective view of such a light guide 94.
  • light is incident from both end faces 94a of the light guide 94 using the optical fiber 88.
  • the light guide 94 has a V-shaped groove (hereinafter referred to as a V-shaped groove) in one of the three side surfaces (bottom surface) 94b. It has a groove 94c.
  • the depth of the V-shaped groove 94c of the lower surface 94b of the light guide 94 becomes deeper according to the directional force at the center, and the width in the direction perpendicular to the lengthwise direction becomes gradually wider toward the center. It has the shape which becomes.
  • a V-shaped groove 95c is formed such that the groove width increases in the length direction from one end face 95a to the other end face 95c, and the groove depth increases.
  • the two transparent bodies 95A and 95B can be configured by closely connecting the end surfaces 95d on the wide groove side. Further, a prism is formed on the wall surface 94e constituting the V-shaped groove 94c of the light guide 94.
  • each optical fiber 88 is connected to an LED (not shown), and the light emitted from the LED can irradiate the end face 94a of the light guide 94. Since the wall surface forming the V-shaped groove 94c of the light guide 94 is inclined with respect to the optical axis of the incident light, the light fino that has entered the light guide 94 from the end face 94a of the light guide 94 is used. The light reaches the wall surface of the V-shaped groove 94c of the light guide 94 and is reflected by the prism formed on the wall surface. The light reflected by the prism of the light guide 94 is incident from the parallel groove 18f of the light guide plate 18, reflected by the inclined rear surface 18d of the light guide plate 18, and then emitted from the light exit surface 18a of the light guide plate 18.
  • FIG. 20A and FIG. 20B show a configuration example of such a light guide plate.
  • FIG. 20A is a schematic cross-sectional view of the light guide plate in which the second light guide is accommodated in the parallel grooves
  • FIG. 20B is a schematic bottom view of the light guide plate in which the back side force is also viewed.
  • FIG. 21 shows a schematic perspective view of the light guide 96 accommodated in such a light guide plate 90.
  • the light guide plate 90 used in the planar illumination device has a parallel groove 90f having a shape in which a section perpendicular to the length direction is removed from an ellipse.
  • the light guide 96 has an outer shape substantially the same as that of the parallel groove 90f so that the light guide 96 is integrally accommodated in the parallel groove 90f of the light guide plate 90.
  • the lower surface 96b of the light guide 96 is formed with a U-shaped groove 96c having a cross-sectional shape perpendicular to the length direction in which a part of an ellipse is removed.
  • the U-shaped groove 96c has a groove depth that gradually increases in the lengthwise direction, and the end faces of the two transparent bodies 97A and 97B on which the groove width is widened are in close contact with each other. Connected.
  • the light guide 96 is disposed in the parallel groove 90f of the light guide plate 90 so that the curved surface thereof is in close contact with the wall surface of the parallel groove 90f of the light guide plate 90.
  • optical fibers 88 are arranged on both end faces 96a of the light guide 96, respectively.
  • the optical fiber 88 can allow light emitted from an LED (not shown) to enter the light guide 96 from the end face 96a of the light guide 96.
  • the incident light is reflected by the wall surface of the U-shaped groove 96c, The light enters the light guide plate 90 through the parallel grooves 90 f of the light guide plate 90. The light is then reflected from the inclined back surface of the light guide plate 90 and then emitted from the light exit surface.
  • FIG. 18A, FIG. 18B, FIG. 20A and FIG. 20B a surface illumination device of a type in which light from an optical fiber is incident from both end faces of a rod-shaped light guide is shown. It is also possible to construct a surface illumination device of a type in which light is incident only on the end face of the light.
  • 22A, 22B, 24A, and 24B show schematic configuration diagrams of a light guide plate (first light guide) used in such a planar illumination device.
  • FIG. 22A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a triangular cross section perpendicular to the length direction, similar to the light guide plate 18 shown in FIGS. 18A and 18B.
  • FIG. 22A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a triangular cross section perpendicular to the length direction, similar to the light guide plate 18 shown in FIGS
  • 21B is a schematic bottom view of the light guide plate as viewed from the rear side.
  • only the one end face 98a is accommodated in the parallel groove of the light guide plate 18 as described above.
  • the schematic perspective view of the light guide 98 in the case of entering is shown.
  • the light guide 98 in the case where light is incident only from one end surface 98a is widened and deepened as it is directed from the end surface 98a on the light incident side to the other end surface 98d.
  • a V-shaped groove 98c is formed on the lower surface 98b so as to be deep.
  • a prism row can be formed on the wall surface forming the V-shaped groove of the light guide 98 like the light guide described above.
  • An optical fiber 88 is disposed on the end face 98a side of the light guide 98 having the smaller cross-sectional area of the V-shaped groove 98c.
  • FIGS. 24A and 24B the light guide plate 90 in which the light guide is housed in the parallel grooves 90f each having a cross-section perpendicular to the length direction with a part of an ellipse removed.
  • a schematic cross-sectional view and a schematic bottom view of the light guide plate 90 viewed from the back side are shown.
  • FIG. 25 shows a schematic perspective view of the light guide 99 that is accommodated in the parallel groove 90f of the light guide plate 90 and in which force light is incident only on one end face.
  • the light guide 90 in the case where light is incident only from one end surface 99a has a width that increases from the end surface 99a on the light incident side toward the other end surface 99d and has a depth.
  • a U-shaped groove 99c is formed on the lower surface 99b so as to be deeper.
  • the U-shaped groove 99c of the light guide plate 90 is formed such that a cross-sectional shape perpendicular to the length direction is a shape obtained by removing a part of an ellipse.
  • a prism row can be formed on the wall surface of the U-shaped groove 99c of the light guide 99.
  • FIG. 26A shows a schematic cross-sectional view of the light guide plate 102 used in the planar lighting device
  • FIG. 26B shows a BB line arrow view
  • FIG. 26C shows FIG.
  • a schematic bottom view showing the rear side force of the light guide plate shown in 6A is shown.
  • a V-shaped groove 102c is formed at a substantially central portion between the inclined back surfaces 102b of the light guide plate 102 so as to gradually deepen from the end surface 102 to the center according to the directional force.
  • a prism array is formed on the wall surface that forms the V-shaped groove 102c, and the prism array can reflect the light incident on the end face force of the light guide plate 102 in a direction perpendicular to the incident direction. .
  • the light reflected by the prism array reaches the inclined back surface 102b, is reflected by the inclined back surface 102b, and exits from the light exit surface 102a.
  • FIGS. 27A to 27C as another configuration example of the light guide plate used in the planar lighting device having no second light guide, it has a cross-sectional shape in which a part of an ellipse is removed.
  • a schematic cross-sectional view of the light guide plate 104 in which the groove is formed on the back surface, a BB line arrow view thereof, and a schematic bottom view of the light guide plate 104 viewed from the back side are shown.
  • a groove 104c having a U-shaped cross section perpendicular to the length direction is formed at the substantially central portion of the inclined rear surface 104b, gradually increasing in depth from the end surface 104d to the center. Is formed.
  • a prism array is formed on the wall surface of the groove. As described above, the prism row can reflect the light incident from the end face 104d of the light guide plate 104 in a direction perpendicular to the incident direction.
  • FIG. 28A shows a schematic cross-sectional view of a light guide plate having a V-shaped groove cross-section
  • FIG. 28B shows a view taken along the line B-B of the light guide plate shown in FIG. 28A, and FIG.
  • FIG. 28A A schematic bottom view of the light guide plate shown in FIG. 28A viewed from the back side is shown.
  • 29A, 29B, and 29C show a schematic cross-sectional view of the light guide plate in the case of a U-shape obtained by cutting a part of an ellipse, a BB line arrow view, and a schematic bottom view. showed that.
  • prism walls are formed on the wall surfaces of the grooves 106c and 108c to reflect light incident from the end faces 106d and 108d in a direction substantially perpendicular to the incident direction.
  • the wall surfaces constituting the grooves 106c and 108c are inclined with respect to the optical axis of the incident light incident from the end faces 106d and 108d by the optical fiber 88. Therefore, the incident light is reflected by the prism row formed on the wall surface, is reflected by the inclined rear surfaces 106b and 108b of the light guide plates 106 and 108, and then exits from the light exit surfaces 106a and 108a.
  • 30A, 30B, and 30C are a schematic cross-sectional view of a light guide plate of a tandem type planar lighting device including the rod-shaped lighting device of the present invention, a partially enlarged cross-sectional view thereof, and the light guide plate as a reflective film. Shows a schematic bottom view seen from the back side with the
  • the tandem planar illumination device 210 includes a plurality of light guide plates 120 having a wedge-shaped cross section, a rod-like illumination device 122, and a reflection film 124.
  • the rod-shaped illumination device 122 includes a rod-shaped light guide 130, an optical fiber 132, and a collimator 134 as shown in FIGS. 30B and 30C.
  • the light guide 130 of the rod-shaped illuminating device 122 is disposed so as to face the side wall surface 120b on the thick side of the light guide plate 120. As shown in FIG.
  • the light guide 130 is formed with a curved surface on the side facing the thick side wall surface 120b of the light guide plate 120, and light can be emitted from the curved surface side.
  • the surface 130b on the side opposite to the curved surface side of the light guide 130 is an inclined surface that inclines toward the curved surface side according to the direction force from the end surface to the center.
  • the reflection film 124 is provided so as to cover the inclined back surface 120c of the light guide plate 120 and the light guide 130 of the rod-like lighting device 122.
  • One end of the optical fiber 132 is connected to a light source (not shown), and the other end is disposed on the end surface 130a side of the light guide body 130 constituting the rod-shaped illuminating device 122.
  • a collimator 134 is provided between the end face 130 a of the light guide 130 and the optical fiber 132.
  • FIGS. 31A to 31C A schematic configuration of a tandem planar illumination device 220 using such a bar illumination device is shown in FIGS. 31A to 31C, respectively.
  • FIG. 31A is a schematic cross-sectional view of a plurality of light guide plates arranged in tandem
  • FIG. 31B is a partial enlarged cross-sectional view thereof
  • FIG. 31C is a light guide plate shown in FIG. 31B except for a reflective film.
  • a light guide 52 having a circular cross-sectional shape perpendicular to the length direction and gradually narrowing from both end faces toward the center is used as the light guide of the rod-shaped illumination device 126.
  • the planar illumination device 220 can also be configured by using the rod-like illumination device 126 having such a light guide 52.
  • FIG. 32A to FIG. 32C show a configuration example of such a planar illumination device 230.
  • FIG. 32A is a schematic cross-sectional view of the tandem light guide plate 120 that constitutes the planar lighting device 230
  • FIG. 32B is a partially enlarged cross-sectional view thereof
  • FIG. 32C is a lead view shown in FIG. 32B.
  • the rod-shaped illuminating device 128 in which light is incident also on one end portion has a light guide 140, an optical fiber 132, and a collimator 134.
  • the light guide 140 of the type that makes light incident from one end face 140a gradually tapers from the end face 140a on the light incident side toward the other end face 140c.
  • the shape is as follows.
  • the light guide 140 has a substantially semicircular cross section perpendicular to the length direction, the side facing the side wall surface on the thick side of the light guide plate is formed as a curved surface, and the opposite surface 140b. Is formed flat.
  • the flat surface 140b of the light guide 140 is inclined with respect to the side wall surface on the thick side of the light guide plate.
  • planar illumination device having such a structure, light is also incident only on one end of the light guide of the planar illumination device, so that the structure of the planar illumination device can be simplified. Miniaturization And low cost can be realized.
  • FIGS. 33A to 33C show another schematic configuration of a planar illumination device using a rod-like illumination device of a type in which one end force light of a light guide is incident.
  • FIG. 33A is a schematic cross-sectional view of a plurality of tandem light guide plates constituting the planar lighting device 240
  • FIG. 33B is a partially enlarged cross-sectional view thereof
  • FIG. 33C is shown in FIG. 33B.
  • FIG. 5 is a schematic bottom view of the light guide plate as viewed from the back side.
  • the cone-shaped light guide 78 shown in FIG. 7C is used V
  • the LED 34 is arranged on the end face (large diameter end face!
  • the rod-shaped illumination device 129 using such a cone-shaped light guide 78 can emit light from the side surface 78c of the light guide 78 as described above.
  • a planar illumination device can be configured.
  • FIG. 34A to FIG. 34C show a configuration example of such a planar illumination device 250.
  • 34A is a schematic cross-sectional view of a plurality of light guide plates 150 arranged in tandem
  • FIG. 34B is a partial enlarged cross-sectional view thereof
  • FIG. 34C is a view of the light guide plate 150 shown in FIG. 34B from the back side. It is a schematic bottom view.
  • the planar illumination device in this embodiment includes a light guide plate 140, a reflection film 124, an optical fiber 132, and a collimator 134, as shown in FIG. 34B.
  • the light guide plate 150 has a wedge-shaped cross section, and the upper surface is a light emitting surface 150a.
  • an incident portion 150b for guiding light to the inside of the light guide 150 is formed on the thick side of the light guide plate 150.
  • the plurality of light guide plates 150 are arranged to be connected to each other such that the light emission surfaces of the light guide plates 150 are flush with each other, and the thin-walled tip portions of the other light guides partially overlap the upper surface of the incident portion 150b.
  • the side wall surface 150c of the incident portion 150b of the light guide plate 150 is formed in a shape inclined with respect to the side wall surface 150d located on the opposite side.
  • the side wall surface 150c of the incident portion 150b in the direction in which the plurality of light guide plates are arranged in tandem is perpendicular to the vertical light incident surface of the incident portion 150b (the surface on the side having the wedge-shaped cross section of the light guide plate) 150e. It is formed to be slanted rather than being formed. Further, the inclined side wall surface 150c of the incident portion 150b A prism row is formed in! RU
  • an optical fiber 132 is disposed on the light incident surface 150e of the incident portion 150 of the light guide plate 150.
  • the optical fiber 132 can irradiate the light incident surface 150e of the incident portion 150b of the light guide plate 150 with light from an LED (not shown).
  • a collimator 134 is provided between the light emitting side end of the optical fiber 132 and the light incident surface 150e of the incident portion 150b of the light guide plate 150.
  • the side wall surface 150c of the incident portion 150b is formed so as to be inclined with respect to the light incident surface 150e as described above, and therefore, the light incident surface 150e via the collimator 134 is formed.
  • Incident light from the optical fiber 132 incident perpendicularly to the light beam is reflected to the thin wall side by the prism array formed on the inclined side wall surface 150c, and then further reflected on the inclined back surface 150f of the light guide plate 150 to obtain a light exit surface. Emits from 150a.
  • FIG. 35A to FIG. 35C show configuration examples of the light guide plate 160 of the planar illumination device 260 when light is incident from both end faces 160e.
  • FIG. 35A is a schematic cross-sectional view of a plurality of light guide plates 160 arranged in tandem
  • FIG. 35B is a partially enlarged cross-sectional view thereof
  • FIG. 35C is a view of the light guide plate 160 shown in FIG. 35B from the back side. It is the typical bottom view seen.
  • the reflective film is removed to show the structure in an easy-to-understand manner.
  • the light guide plate 160 is formed such that the side wall surface 160c of the incident portion 160b is inclined toward the thin wall side surface 160d according to the directional force toward the center.
  • prism rows are formed on the side wall surface 160c of the inclined incident portion 160b in the same manner as described above.
  • optical fibers 132 are disposed on both light incident surfaces 160e of the incident portion 160b, and a collimator 134 is provided between the end of the optical fiber 132 and the light incident surface 160e of the light incident portion 160b. Has been placed.
  • the light incident from the light incident surface 160b is reflected toward the thin wall side by the prism row on the side wall surface 160c of the incident portion 160b and then the inclined back surface 160f of the light guide plate 160. Then, the light is further reflected and emitted from the light exit surface 160a.
  • the planar lighting device has a configuration in which a plurality of light guide plates are arranged in tandem, but the light guide plates may be integrally formed as one member.
  • the grooves have V-shaped and U-shaped shapes.
  • the shape can be any shape such as, but not limited to, a circle, a parabola, and a hyperbola.
  • the light guide member and the light guide plate of the present invention can effectively use light emitted from a point light source, particularly a light emitting diode, and use a cold cathode tube. It can be made thinner and lighter than the light guide plate, and the occurrence of unevenness and uneven brightness can be reduced.
  • a light guide member and a light guide plate are optimal as a light guide member and a light guide plate used for a knock light unit of a liquid crystal panel.
  • the planar illumination device of the present invention uses the light guide member or the light guide plate, the use wavelength of the light source can be adjusted without using a cold cathode tube as the illumination light source.
  • the light source can be used, the color reproduction range with high color reproducibility can be expanded, the saturation can be improved, and the thickness and weight can be reduced.
  • the bar-shaped illuminating device of the present invention allows the light from a point light source such as a double-sided force LED of a columnar light guide to be incident and emits the incident light with a sidewall force. It can be used in place of the cold cathode tube of the lighting device.
  • a point light source such as a double-sided force LED of a columnar light guide
  • the shape of the light guide can be processed into a desired shape, it is optimal as a light source for a planar illumination device having a thin light guide plate.
  • a pseudo white LED or RGB-LED can be used as the point light source, it is possible to expand the color reproduction range and improve the saturation with high color reproducibility.
  • the planar illumination device of the present invention uses a so-called tandem light guide plate as the light guide plate, and uses the above bar illumination device without using a cold cathode tube as the illumination light source. It is possible to expand the color reproduction range with high actuality and improve the saturation, and to reduce the thickness and weight.

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Abstract

A light guide member, a planar lighting apparatus using the light guide member, and a bar-like lighting apparatus. The light guide member comprises a transparent plate-like first light guide body having a rectangular light emitting surface and in which a parallel groove positioned parallel with one side of the light emitting surface is formed in a rear surface positioned on the opposite side of the rectangular light emitting surface and a transparent second light guide body stored in the parallel groove and formed in a columnar outside shape. The planar lighting apparatus comprises the light guide member and a spot light source. A light from the spot light source is led therein from both end faces of the second light guide body. The bar-like lighting apparatus comprises the spot light source and the light guide body formed in a columnar shape and having an outer diameter gradually reduced from the both end faces toward the center thereof. The light of the spot light source is led into the bar-like lighting apparatus from both ends of the light guide device, and the incident light is allowed to outgo from the side walls of the light guide body.

Description

明 細 書  Specification
導光部材及びそれを用いた面状照明装置並びに棒状照明装置 技術分野  TECHNICAL FIELD The present invention relates to a light guide member, a planar illumination device using the same, and a rod illumination device.
[0001] 本発明は、バックライトユニットに用いられる導光部材及びそれを用いた面状照明 装置並びに棒状照明装置に関する。  The present invention relates to a light guide member used in a backlight unit, a planar illumination device using the same, and a rod-like illumination device.
背景技術  Background art
[0002] 液晶表示装置には、液晶パネル (LCD)の裏面側力 光を照射し、液晶パネルを 照明するバックライトユニットが用いられている。バックライトユニットは、照明用の光源 、この光源力 出射した光を拡散して液晶パネルを照射する導光板、導光板から放 射される光を均一化するプリズムシートや拡散シートなどの部品を用いて構成される  A liquid crystal display device uses a backlight unit that illuminates the liquid crystal panel by irradiating the back side of the liquid crystal panel (LCD). The backlight unit uses components such as a light source for illumination, a light guide plate that diffuses the emitted light and irradiates the liquid crystal panel, and a prism sheet and a diffusion sheet that uniformize the light emitted from the light guide plate. Composed
[0003] 現在、大型の液晶テレビのバックライトユニットは、照明用の光源の直上に導光板を 配置した、いわゆる直下型と呼ばれる方式が主流である（例えば、実開平 5— 4133 号公報 (以下、特許文献 1という）参照)。本方式は、光源である冷陰極管を液晶パネ ルの背面に複数本配置し、内部を白色の反射面として均一な光量分布と必要な輝 度を確保している。し力しながら、本方式において光量分布を均一にするためには、 原理的には、液晶パネルに垂直方向の厚みが 30mm程度必要である。 [0003] Currently, a backlight unit of a large-sized liquid crystal television is mainly used in a so-called direct type in which a light guide plate is disposed immediately above a light source for illumination (for example, Japanese Utility Model Laid-Open No. 5-4133 (hereinafter referred to as Japanese Utility Model Laid-Open No. 5-4133)). And referred to as Patent Document 1)). In this method, a plurality of cold-cathode tubes, which are light sources, are arranged on the back of the liquid crystal panel, and the inside is a white reflective surface to ensure a uniform light distribution and the required brightness. However, in order to make the light intensity distribution uniform in this method, in principle, the liquid crystal panel needs to have a thickness of about 30 mm in the vertical direction.
[0004] 近年、液晶表示装置の薄型化、低消費電力化、大型化が要望されているが、上述 した直下型のバックライトユニットでは、導光板の厚さを 10mm以下の厚みにすると光 量ムラが発生するため、薄型化には限界があった。このような液晶表示装置の薄型 ィ匕、低消費電力化、大型化を実現するために種々の形状の導光板が提案されてい る（特開平 9— 304623号公報、特開平 10— 133027号公報及び特開 2001— 423 27号公報 (以下、それぞれ特許文献 2、特許文献 3及び特許文献 4という）参照)。  [0004] In recent years, there has been a demand for thinner, lower power consumption, and larger liquid crystal display devices. However, in the above-described direct-type backlight unit, when the thickness of the light guide plate is 10 mm or less, the amount of light is reduced. Since unevenness occurs, there is a limit to reducing the thickness. In order to realize such a thin liquid crystal display device with low power consumption and large size, various shapes of light guide plates have been proposed (Japanese Patent Laid-Open Nos. 9-304623 and 10-133027). And JP-A-2001-42327 (referred to as Patent Document 2, Patent Document 3, and Patent Document 4, respectively).
[0005] 例えば、特許文献 2には、略長方形形状を有する導光板に形成される溝に蛍光ラ ンプを埋め込み、導光板の背面に反射シートを配置し、導光板の出射面に透過光量 補正シート、光拡散板、プリズムシートを積層することで形成される面光源装置 (バッ クライトユニット）が開示されている。 [0006] また、特許文献 3には、液晶表示装置の額縁を狭くし、厚みを薄くすることができ、 光利用効率がよく明るいバックライトユニットを得るために、光源を配置するための凹 部の幅方向に平行な断面の形状が、深さ方向を主軸とする放物線形状である導光 体 (導光板)が開示されて ヽる。 [0005] For example, in Patent Document 2, a fluorescent lamp is embedded in a groove formed in a light guide plate having a substantially rectangular shape, a reflective sheet is disposed on the back surface of the light guide plate, and the amount of transmitted light is corrected on the exit surface of the light guide plate. A surface light source device (backlight unit) formed by laminating a sheet, a light diffusion plate, and a prism sheet is disclosed. [0006] Further, Patent Document 3 discloses a concave portion for arranging a light source in order to obtain a bright backlight unit that can reduce the frame thickness of the liquid crystal display device and reduce the thickness thereof and has high light utilization efficiency. A light guide (light guide plate) in which the shape of the cross section parallel to the width direction is a parabolic shape with the depth direction as the main axis is disclosed.
[0007] 特許文献 2及び 3に開示された導光板は、液晶表示装置の薄型化、小型軽量化、 低消費電力化、低コストィ匕などのいくつかを図るためのものである力 いずれもその 中央部に 1つまたは複数の溝が設けられ、その溝に棒状光源を収納する構成とされ 、好ましくは、溝部力も端面に向力つて板厚が次第に薄くなるように形成されおり、薄 型化を達成している。  [0007] The light guide plates disclosed in Patent Documents 2 and 3 are all used to reduce the thickness, size, weight, power consumption, and cost of the liquid crystal display device. One or a plurality of grooves are provided in the central portion, and the rod-shaped light source is accommodated in the groove. Preferably, the groove portion force is also directed toward the end surface so that the plate thickness gradually decreases, and the thickness is reduced. Has achieved.
[0008] また、特許文献 4では、液晶バックライトを壁掛けテレビの大型液晶表示面用に改 良する為に、複数の導光板を並列に配置し、導光板間に所定数の線状光源を配置 して高輝度にして高均一の大型の背面照明を実現している。  [0008] Also, in Patent Document 4, in order to improve the liquid crystal backlight for a large liquid crystal display surface of a wall-mounted television, a plurality of light guide plates are arranged in parallel, and a predetermined number of linear light sources are arranged between the light guide plates. It has been arranged to achieve high brightness and achieve a highly uniform large backlight.
[0009] ところで、上記特許文献 1〜4に開示の液晶表示装置においては、ノ ックライトュ- ットの光源として冷陰極管を使用している。近年、冷陰極管の代わりに LED (発光ダ ィオード）を光源として用いるノ ックライトユニットが提案されている。例えば、特開平 9 — 259623号公報（以下、特許文献 5という）には、板状の導光板の少なくとも一辺を 光源取付辺とし、この光源取付辺に凹面状の光導入部を適宜数設け、この光導入部 のそれぞれに LEDランプを対畤させて成る LED光源モジュールに関する発明が開 示されている。特許文献 5では、光源取付辺に、光導入部の一対を、お互いが隣り合 う側である内側部の光源取付辺への切込みを直角に近付け、外側部の光源取込辺 への切込みを平行に近付けた凹面状として形成し、一対の光導入部間には凹面状 とした反射面を設けている。  Meanwhile, in the liquid crystal display devices disclosed in Patent Documents 1 to 4, a cold cathode tube is used as a light source of the knock light. In recent years, knock light units have been proposed that use LEDs (light-emitting diodes) as light sources instead of cold-cathode tubes. For example, in JP-A-9-259623 (hereinafter referred to as Patent Document 5), at least one side of a plate-shaped light guide plate is used as a light source mounting side, and an appropriate number of concave light introducing portions are provided on the light source mounting side. An invention relating to an LED light source module in which an LED lamp is opposed to each of the light introducing portions is disclosed. In Patent Document 5, a pair of light introducing portions are placed close to the light source mounting side, and the notch into the light source mounting side on the inner side that is adjacent to each other is brought to a right angle, and the notch into the light source receiving side on the outer side is made. It is formed as a concave surface approaching parallel, and a concave reflecting surface is provided between the pair of light introducing portions.
[0010] また、特開 2001— 110223号公報（以下、特許文献 6という）には、電気光学パネ ルの前面側に対向配置された板状の第 1の導光体と、第 1の導光体の側端面に沿つ て伸びた第 2の導光体と、第 2の導光体の端部から光を入射させる点状光源と、第 2 の導光体の端部から第 2の導光体への光の入射を妨げる入射領域制限手段を備え る電気光学装置が開示されている。ここでは、第 2の導光体として、棒状 (角柱)の透 光性の榭脂成形品を用いており、この導光体の両端部に点状光源を配置して、点状 光源の光を第 2の導光体の内部に導き、導光体の側壁力 光を出射させている。 [0010] In addition, Japanese Patent Laid-Open No. 2001-110223 (hereinafter referred to as Patent Document 6) discloses a plate-shaped first light guide disposed opposite to the front side of an electro-optical panel, and a first guide. A second light guide extending along the side end surface of the light body, a point light source for allowing light to enter from the end of the second light guide, and a second light source from the end of the second light guide. An electro-optical device including an incident region limiting unit that prevents light from entering the light guide is disclosed. Here, as the second light guide, a rod-shaped (rectangular) translucent resin molded product is used, and point light sources are arranged at both ends of the light guide to provide a point-like shape. The light from the light source is guided into the second light guide, and the side wall force light of the light guide is emitted.
[0011] また、特開 2000— 268622号公報（以下、特許文献 7という）には、光源として、透 光性材料から成る導光体と、導光体の少なくとも一端部に配置される点状光源とで構 成される光源を用いた面状照明装置が開示されている。導光体は、その断面形状が 四角形、円形、点状光源力 遠ざ力るに従って断面積が減少する導光体であり、矩 形状の導光板の側端面付近に配置されて 、る。 [0011] Further, Japanese Patent Laid-Open No. 2000-268622 (hereinafter referred to as Patent Document 7) discloses a light guide made of a light-transmitting material as a light source, and a dot-like shape disposed at at least one end of the light guide. A planar illumination device using a light source composed of a light source is disclosed. The light guide is a light guide whose cross-sectional shape decreases as the cross-sectional shape is square, circular, or point-like light source power increases, and is arranged near the side end face of the rectangular light guide plate.
特許文献 1 :実開平 5— 4133号公報  Patent Document 1: Japanese Utility Model Publication No. 5-4133
特許文献 2：特開平 9 - 304623号公報  Patent Document 2: Japanese Patent Laid-Open No. 9-304623
特許文献 3 :特開平 10— 133027号公報  Patent Document 3: JP-A-10-133027
特許文献 4:特開 2001— 42327号公報  Patent Document 4: Japanese Patent Laid-Open No. 2001-42327
特許文献 5：特開平 9 - 259623号公報  Patent Document 5: Japanese Patent Laid-Open No. 9-259623
特許文献 6：特開 2001— 110223号公報  Patent Document 6: Japanese Unexamined Patent Publication No. 2001-110223
特許文献 7：特開 2000 - 268622号公報  Patent Document 7: Japanese Unexamined Patent Publication No. 2000-268622
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0012] これら特許文献 5〜7に開示されている照明装置は、略矩形状の導光板の一方の 側面力 発光ダイオードの光を入射させるサイドライト方式を採用しており、光源の光 の利用において、その光量や分布の制御に難点がある。 [0012] The lighting devices disclosed in these Patent Documents 5 to 7 employ a side light system in which light from a light emitting diode is incident on one side of a substantially rectangular light guide plate, and use of light from a light source However, there is a difficulty in controlling the light quantity and distribution.
また、特許文献 2〜4に開示されているような、導光板に形成された溝に冷陰極管 を収容するタイプの導光板では、導光板の厚みを薄くしてしまうと、溝に配置された 冷陰極管の直上における輝度が強くなつてしまい、輝度むらが顕著になるため、薄型 ィ匕には限界がある。  Further, in the light guide plate of the type in which the cold cathode tube is accommodated in the groove formed in the light guide plate as disclosed in Patent Documents 2 to 4, if the thickness of the light guide plate is reduced, the light guide plate is disposed in the groove. Since the luminance directly above the cold cathode tube becomes strong and the luminance unevenness becomes remarkable, there is a limit to the thin panel.
[0013] 本発明は、上記実情に鑑みてなされたものであり、本発明の目的は、冷陰極管を 用いた導光板よりも薄型で、点状光源、特に発光ダイオードが発する光を有効に利 用することができる導光部材及びそれを用いた面状照明装置、その面状照明装置に 用いられる棒状照明装置を提供することにある。  The present invention has been made in view of the above circumstances, and an object of the present invention is thinner than a light guide plate using a cold-cathode tube and effectively utilizes light emitted from a point light source, particularly a light-emitting diode. An object of the present invention is to provide a light guide member that can be used, a planar illumination device using the same, and a rod-like illumination device used in the planar illumination device.
[0014] また、本発明の別の目的は、均一でむらが少なぐ高輝度の照明光を出射すること ができる導光部材及びそれを用いた面状照明装置並びにその面状照明装置に用い られる棒状照明装置を提供することにある。 [0014] Further, another object of the present invention is to use a light guide member capable of emitting high-luminance illumination light that is uniform and has less unevenness, a planar illumination device using the same, and a planar illumination device using the same. It is in providing the rod-shaped illuminating device.
[0015] また、本発明の更に別の目的は、色再現性が高ぐ薄型の導光板に最適に用いる ことができる棒状照明装置を提供することにある。  [0015] Still another object of the present invention is to provide a rod-like illumination device that can be optimally used for a thin light guide plate with high color reproducibility.
課題を解決するための手段  Means for solving the problem
[0016] 上記目的を達成するために、本発明の第 1の態様は、透明な導光部材であって、 矩形状光射出面を有し、前記矩形状光射出面と反対側に位置する背面に前記矩形 状光射出面の一辺に平行な平行溝が形成された透明な板状の第 1導光体と、前記 平行溝内に収容される柱状の外形を有する透明な第 2導光体とから構成される導光 部材を提供するものである。  [0016] In order to achieve the above object, a first aspect of the present invention is a transparent light guide member, which has a rectangular light emission surface and is located on the opposite side of the rectangular light emission surface. A transparent plate-shaped first light guide having a parallel groove parallel to one side of the rectangular light exit surface on the back surface, and a transparent second light guide having a columnar outer shape accommodated in the parallel groove. The light guide member comprised from a body is provided.
[0017] 本発明の第 1の態様の導光部材において、前記第 2導光体は、前記平行溝と略同 形状の断面形状を有して構成されていることが好ましぐ一方の端面から他方の端面 に向かうに従って外径が小さくなる形状を有する 1組の導光体を、その外径の小さい 側の端面同士を接続することによって構成されて 、ることが好ま 、。  [0017] In the light guide member according to the first aspect of the present invention, it is preferable that the second light guide has a cross-sectional shape substantially the same shape as the parallel groove. It is preferable that a pair of light guides having a shape in which the outer diameter decreases from one end to the other end face is configured by connecting the end faces on the smaller outer diameter side.
[0018] また、前記第 1導光体の背面は、前記平行溝の中心軸を含み前記矩形状光射出 面に垂直な面に対して対称な 1対の傾斜背面を有し、前記傾斜背面は、それぞれ、 前記中心軸部分力 前記一辺に直交する方向の端部に向かうに従って肉厚が薄く なるように前記矩形状光射出面に対して傾斜している単数もしくは複数の構造が前 記薄肉部で連結された形状であることが好ましい。  [0018] The back surface of the first light guide has a pair of inclined back surfaces that are symmetrical with respect to a plane that includes the central axis of the parallel grooves and is perpendicular to the rectangular light exit surface, and the inclined back surface. The central axis partial force has one or more structures that are inclined with respect to the rectangular light exit surface such that the thickness decreases toward the end in the direction orthogonal to the one side. It is preferable that it is the shape connected by the part.
[0019] また、本発明の導光部材においては、前記第 2導光体の前記平行溝から露出する 露出面が、前記矩形状光射出面に対して傾斜していることが好ましぐ前記第 2導光 体の前記露出面にプリズム列が形成されていることが好ましい。  In the light guide member of the present invention, it is preferable that an exposed surface exposed from the parallel groove of the second light guide is inclined with respect to the rectangular light exit surface. It is preferable that a prism row is formed on the exposed surface of the second light guide.
[0020] また、本発明の導光部材の前記第 2導光体の長さ方向に垂直な断面形状が、三角 形状、円形状、楕円の一部を切断した形状、又は放物線の一部の形状であることが 好ましい。  [0020] The cross-sectional shape perpendicular to the length direction of the second light guide of the light guide member of the present invention is a triangular shape, a circular shape, a shape obtained by cutting a part of an ellipse, or a part of a parabola. The shape is preferred.
[0021] また、前記第 2導光体は、長さ方向における両方の端面から光が入射され、前記両 方の端面力 中央に向かうに従って幅が広くなるとともに深さが深くなる溝を有するこ とが好ましい。または、前記第 2導光体は、長さ方向における一方の端面力も光が入 射され、光が入射する側の前記端面力 他方の端面に向かうに従って幅が広くなると ともに深さが深くなる溝を有することが好ましい。この場合において、前記第 2導光体 の前記溝は V字状または U字状の溝であることが好ましい。 [0021] Further, the second light guide has a groove in which light enters from both end faces in the length direction and becomes wider and deeper toward the center of both end face forces. Are preferred. Alternatively, when the second light guide is also incident on one end surface force in the length direction, and the width becomes wider toward the other end surface, the end surface force on the light incident side. It is preferable that both have grooves with a deeper depth. In this case, the groove of the second light guide is preferably a V-shaped or U-shaped groove.
[0022] 本発明の第 2の態様は、本発明の第 1の態様の導光部材と、点状光源とを有し、前 記第 2導光体の両端面から前記点状光源からの光が入光される面状照明装置を提 供するものである。 [0022] A second aspect of the present invention includes the light guide member of the first aspect of the present invention and a point light source, and the light from the point light source from both end faces of the second light guide. It provides a surface illumination device that receives light.
[0023] 本発明の面状照明装置において、前記点状光源が前記第 2導光体の両端面に配 置されて!、ることが好まし!/、。  [0023] In the planar illumination device of the present invention, it is preferable that the point light sources are arranged on both end faces of the second light guide body!
[0024] また、本発明の面状照明装置は、更に、前記点状光源の光を前記第 2導光体の端 面に導くためのライトガイドを有することが好ましい。  [0024] The planar illumination device of the present invention preferably further includes a light guide for guiding the light from the point light source to the end surface of the second light guide.
[0025] 本発明の面状照明装置においては、前記点状光源力LEDであることが好ましぐ 擬似白色 LED又は RGB— LEDであることがより好ましい。  In the planar lighting device of the present invention, the point light source power LED is preferable. A pseudo white LED or RGB-LED is more preferable.
[0026] 本発明の第 3の態様は、棒状照明装置であって、点状光源と、柱状の形状を有し、 両端面から中央に向かうに従って外径力 、さくなる導光体とを有し、前記導光体の両 端力 前記点状光源の光を入射させて、その入射した光を前記導光体の側壁から出 射する棒状照明装置を提供するものである。  [0026] A third aspect of the present invention is a rod-shaped illumination device having a point light source and a light guide that has a columnar shape and has an outer diameter force that decreases from both end faces toward the center. Then, both end forces of the light guide are provided. A rod-shaped illuminating device that allows the light from the point light source to enter and emits the incident light from the side wall of the light guide.
[0027] 本発明の第 3の態様の棒状照明装置において、前記導光体は、一方の端面から他 方の端面に向かうに従って外径力 、さくなる形状を有する一組の導光体を、それら 導光体の外径の小さ 、端面同士が互 、に密着して構成されて 、ることが好ま 、。  [0027] In the rod-shaped illuminating device according to the third aspect of the present invention, the light guide includes a set of light guides having a shape that decreases in outer diameter force from one end face toward the other end face. It is preferable that the outer diameters of the light guides are small and the end surfaces are in close contact with each other.
[0028] また、矩形状光射出面を有し、前記矩形状光射出面と反対側に位置する背面の中 央部分に前記矩形状光射出面の一辺に平行な平行溝が形成された透明な導光板 を有する面状照明装置に用いられ、前記導光体が、前記導光板の平行溝と略同形 状の外形を有し、かつ前記平行溝内に配置されることが好ましい。  [0028] In addition, a transparent light source having a rectangular light emission surface and having a parallel groove parallel to one side of the rectangular light emission surface is formed in the center of the back surface located on the opposite side of the rectangular light emission surface. Preferably, the light guide body has an outer shape substantially the same shape as the parallel groove of the light guide plate, and is disposed in the parallel groove.
[0029] また、前記導光体の側面のうち、前記導光板の前記平行溝を形成する側壁と対向 する側面以外の側面があり、この側面は光の反射が行われるように面が平坦面や曲 面に形成されて ヽても良く、当該側面にプリズム列が形成されて ヽることが好ま ヽ。  [0029] Further, of the side surfaces of the light guide, there are side surfaces other than the side surfaces facing the side walls forming the parallel grooves of the light guide plate, and the side surfaces are flat so that light is reflected. It may be formed on a curved surface, and it is preferable that a prism row is formed on the side surface.
[0030] 前記導光体の軸方向に垂直な断面形状が、三角形状、円形状、楕円の一部を切 断した形状、又は放物線の一部の形状であることが好ま U、。  [0030] It is preferable that the cross-sectional shape perpendicular to the axial direction of the light guide body is a triangular shape, a circular shape, a shape obtained by cutting a part of an ellipse, or a shape of a part of a parabola.
[0031] また、更に、前記点状光源が発する光を前記導光体の端面に導くためのライトガイ ドを備えることが好ましい。また、前記点状光源が、 LEDであることが好ましぐ擬似 白色 LED又は RGB— LEDであることがより好ましい。また、前記 RGB— LEDは、順 次パルス点灯することが好まし 、。 [0031] Further, a light guide for guiding the light emitted from the point light source to the end face of the light guide. Preferably. The point light source is more preferably a pseudo white LED or RGB-LED, which is preferably an LED. In addition, the RGB-LED preferably lights up sequentially.
[0032] 本発明の第 4の態様は、面状照明装置であって、本発明の第 3の態様の棒状照明 装置と、矩形状光射出面と、前記矩形状光射出面の一辺から、当該一辺に向かい合 う対辺に向力つて板厚が薄くなるように、前記矩形状光射出面に対して傾斜する傾 斜背面とを有する複数の透明な導光板とを有し、前記複数の導光板は、前記矩形状 光射出面が同一平面を形成するとともに、前記一辺を含む側面が、前記対辺を含む 側面と接するように配列されており、前記傾斜背面と前記一辺を含む側面とによって 形成される空間に、前記棒状照明装置の導光体が配置されている面状照明装置を 提供するものである。  [0032] A fourth aspect of the present invention is a planar illumination device, the rod-shaped illumination device according to the third aspect of the present invention, a rectangular light exit surface, and one side of the rectangular light exit surface, A plurality of transparent light guide plates each having an inclined back surface that is inclined with respect to the rectangular light exit surface so that the plate thickness is reduced by applying force to the opposite side facing the one side; The light guide plate is arranged such that the rectangular light exit surfaces form the same plane, the side surface including the one side is in contact with the side surface including the opposite side, and the inclined back surface and the side surface including the one side The present invention provides a planar illumination device in which a light guide body of the rod-shaped illumination device is disposed in a formed space.
[0033] また、本発明の第 5の態様は、透明な導光板であって、矩形状の光射出面と、前記 光射出面と反対側に位置し、前記光射出面の一辺に平行な溝が略中央に形成され ている背面とを有し、前記溝は、両方の端面から中央に向かうに従って次第に溝深さ が深くなるとともに溝幅が広くなる形状を有する導光板を提供するものである。  [0033] Further, a fifth aspect of the present invention is a transparent light guide plate, which is positioned on the opposite side of the light emitting surface, and is parallel to one side of the light emitting surface. A light guide plate having a shape in which the groove depth gradually increases and the groove width gradually increases from both end faces toward the center. is there.
[0034] また、本発明の第 6の態様は、透明な導光板であって、矩形状の光射出面と、前記 光射出面と反対側に位置し、前記光射出面の一辺に平行な溝が略中央に形成され ている背面とを有し、前記溝は、一方の端面から他方の端面に向かうに従って次第 に溝深さが深くなるとともに溝幅が広くなる形状を有する導光板を提供するものであ る。  [0034] Further, a sixth aspect of the present invention is a transparent light guide plate, which is positioned on the opposite side of the light emitting surface with a rectangular shape and parallel to one side of the light emitting surface. A light guide plate having a shape in which the groove depth gradually increases and the groove width gradually increases from one end face to the other end face. To do.
[0035] 本発明の第 5及び第 6の態様の導光板において、前記溝を挟んで両側に位置する 前記背面は、前記光射出面に対して傾斜していることが好ましい。  In the light guide plates of the fifth and sixth aspects of the present invention, it is preferable that the back surface located on both sides of the groove is inclined with respect to the light emitting surface.
[0036] また、本発明の第 7の態様は、面状照明装置であって、本発明の第 5又は第 6の態 様の導光板と、点状光源と、前記点状光源で発せられた光を前記導光板の端面の 前記溝が形成されている部分に導くための追加の導光部材とを有する面状照明装 置を提供するものである。  [0036] Further, a seventh aspect of the present invention is a planar illumination device, which is emitted from the light guide plate according to the fifth or sixth aspect of the present invention, a point light source, and the point light source. The planar lighting device has an additional light guide member for guiding the light to the portion of the end face of the light guide plate where the groove is formed.
[0037] また、本発明の第 8の態様は、透明な導光板であって、矩形状光射出面と、前記矩 形状光射出面の一辺から、当該一辺に向かい合う対辺に向かって板厚が薄くなるよ うに、前記矩形状光射出面に対して傾斜する傾斜背面と、前記一辺を含む側面に形 成され、前記一辺に垂直な光入射面、及び、当該光入射面から内部に入射する光を 、前記対辺を含む側面側に反射させる傾斜面を含む光入射部とを有する導光板を 提供するものである。 [0037] Further, an eighth aspect of the present invention is a transparent light guide plate having a rectangular light emission surface and a plate thickness from one side of the rectangular light emission surface toward the opposite side facing the one side. It will be thinner In other words, an inclined back surface that is inclined with respect to the rectangular light exit surface, a side surface including the one side, a light incident surface that is perpendicular to the one side, and light incident on the inside from the light incident surface are: A light guide plate having a light incident portion including an inclined surface that is reflected on a side surface including the opposite side is provided.
[0038] 本発明の第 8の態様の導光板においては、前記光入射部の前記光入射面は、前 記導光板の前記一辺に垂直な両方の端面に形成されており、前記光入射部の前記 傾斜面は、前記両方の端面から中央に向かうに従って傾斜して 、ることが好ま 、。 または、前記光入射部の前記光入射面は、前記導光板の前記一辺に垂直な 2つの 端面のうちの一方の端面に形成されており、前記光入射部の前記傾斜面は、前記一 方の端面力 他方の端面に向かうに従って傾斜していることが好ましい。  [0038] In the light guide plate of the eighth aspect of the present invention, the light incident surfaces of the light incident portions are formed on both end faces perpendicular to the one side of the light guide plate, and the light incident portions It is preferable that the inclined surface is inclined toward the center from the both end surfaces. Alternatively, the light incident surface of the light incident portion is formed on one end surface of two end surfaces perpendicular to the one side of the light guide plate, and the inclined surface of the light incident portion is the one side. It is preferable that it is inclined as it goes to the other end surface.
[0039] また、本発明の第 9の態様は、面状照明装置であって、本発明の第 7の態様の導光 板と、点状光源とを備え、前記点状光源の光を前記導光板の前記光入射面に照射 する面状照明装置を提供するものである。  [0039] Further, a ninth aspect of the present invention is a planar illumination device, comprising the light guide plate according to the seventh aspect of the present invention and a point light source, wherein the light from the point light source is A planar illumination device for irradiating the light incident surface of the light guide plate is provided.
発明の効果  The invention's effect
[0040] 本発明の第 1の態様の導光部材は、第 2導光体により内部に光を導いて第 1導光 体の光射出面力も光を出射することができ、冷陰極管の代わりに発光ダイオード (LE D)などの点状光源を用いることができ、薄型化することができる。また、第 2導光体の 外形を、第 1導光体の平行溝の形状に合わせた形状に加工することができるので、 第 1導光体の平行溝を輝度むらが抑制されるような形状にするとともに、第 2導光体 の外形を、それに応じた外形に加工すれば、輝度むらの発生を低減することができ、 かつ薄型の導光部材とすることができる。すなわち、第 1導光体の光射出面における 輝線を抑制するために、第 1導光体の平行溝の形状と、第 2導光体の外形を自由に 設計することができる。このような導光部材は、液晶パネルのバックライトユニットに用 V、られる導光部材として最適である。  [0040] The light guide member of the first aspect of the present invention can guide light into the inside by the second light guide and also emit light with the light emission surface force of the first light guide. Instead, a point light source such as a light emitting diode (LE D) can be used, and the thickness can be reduced. In addition, since the outer shape of the second light guide can be processed into a shape that matches the shape of the parallel grooves of the first light guide, the uneven brightness of the parallel grooves of the first light guide is suppressed. If the outer shape of the second light guide is processed into the shape corresponding to the shape, the occurrence of uneven brightness can be reduced, and a thin light guide member can be obtained. That is, the shape of the parallel grooves of the first light guide and the outer shape of the second light guide can be freely designed in order to suppress the bright lines on the light exit surface of the first light guide. Such a light guide member is most suitable as a light guide member used for a backlight unit of a liquid crystal panel.
[0041] また、本発明の第 2の態様の面状照明装置は、照明用光源として冷陰極管を用い ずに、光源の使用波長の調整が可能である発光ダイオードなどの点状光源を用いて いるので、色再現性が高ぐ色再現域の拡大、彩度の向上を図ることができる。  [0041] In addition, the planar illumination device according to the second aspect of the present invention uses a point light source such as a light-emitting diode capable of adjusting the used wavelength of the light source without using a cold cathode tube as the illumination light source. Therefore, it is possible to expand the color reproduction range where the color reproducibility is high and to improve the saturation.
[0042] 本発明の第 3の態様の棒状照明装置は、柱状の導光体の両端面力 LEDなどの 点状光源の光を入射させて、その入射光を側壁力も出射することができるので、面状 照明装置の冷陰極管の代わりに用いることができる。特に、導光体の形状を所望の 形状に加工することができるので、薄型の導光板を有する面状照明装置の光源とし て最適である。更に、点状光源として擬似白色 LED又は RGB— LEDを用いることが できるので、色再現性が高ぐ色再現域の拡大、彩度の向上を図ることができる。 [0042] The rod-shaped illuminating device of the third aspect of the present invention includes a double-sided force LED of a columnar light guide and the like. Since the light from the point light source can be incident and the incident light can be emitted also with the side wall force, it can be used instead of the cold cathode tube of the planar illumination device. In particular, since the shape of the light guide can be processed into a desired shape, it is optimal as a light source for a planar illumination device having a thin light guide plate. Furthermore, since a pseudo-white LED or RGB-LED can be used as the point light source, it is possible to expand the color reproduction range with high color reproducibility and improve the saturation.
[0043] 本発明の第 4の態様の面状照明装置は、導光板としていわゆるタンデム型の導光 板を用い、照明用光源として冷陰極管を用いずに、柱状の導光体の両端面から LE Dなどの点状光源の光を入射させて、その入射光を側壁から出射する本発明の第 3 の態様の棒状照明装置を用いているので、色再現性が高ぐ色再現域の拡大、彩度 の向上を図ることができるとともに、薄型化及び軽量ィ匕を図ることができる。  [0043] The planar illuminating device according to the fourth aspect of the present invention uses a so-called tandem light guide plate as the light guide plate, and uses both end faces of the columnar light guide without using a cold cathode tube as the illumination light source. Since the rod-shaped illumination device according to the third aspect of the present invention in which the light of a point light source such as LED is incident and the incident light is emitted from the side wall is used, a color gamut with high color reproducibility is used. In addition to being able to increase magnification and saturation, it is also possible to reduce the thickness and weight.
[0044] また、本発明の第 5及び第 6の態様の導光板は、矩形状の光射出面と反対側の背 面の略中央部分に、光射出面の一辺に平行な溝を形成した構成であるので、導光 板の下面に光源を配置するための領域を設ける必要が無ぐ薄型化及び軽量ィ匕を 実現することができる。また、本発明の第 5及び第 6の態様の導光板によれば、光源と して LEDなどの点状光源を用いることができ、導光板の端面力も入射する点状光源 の光を、溝を構成する壁面で反射させた後、矩形状の光射出面から出射させること ができるので、光の利用効率を高めることができる。このような導光板も液晶パネルの ノ ックライトユニットに用いられる導光板として最適である。  [0044] Further, in the light guide plate according to the fifth and sixth aspects of the present invention, a groove parallel to one side of the light emission surface is formed in a substantially central portion of the back surface opposite to the rectangular light emission surface. Because of the configuration, it is possible to realize a reduction in thickness and weight without having to provide a region for arranging the light source on the lower surface of the light guide plate. Further, according to the light guide plate of the fifth and sixth aspects of the present invention, a point light source such as an LED can be used as the light source, and the light from the point light source that is also incident on the end face force of the light guide plate is grooved. Since the light can be emitted from the rectangular light exit surface after being reflected by the wall surface constituting the light, the light utilization efficiency can be increased. Such a light guide plate is also optimal as a light guide plate used in a knock light unit of a liquid crystal panel.
[0045] 本発明の第 7の態様の面状照明装置は、本発明の第 5又は第 6の態様の導光板を 備えるので、光の利用効率が高められ、薄型化及び軽量化を実現することができ、ま た、 LEDなどの点状光源を用いることができるので色再現性が高ぐ色再現域の拡 大、彩度の向上を図ることができる。  [0045] Since the planar lighting device according to the seventh aspect of the present invention includes the light guide plate according to the fifth or sixth aspect of the present invention, the light use efficiency is improved, and a reduction in thickness and weight is realized. In addition, since a point light source such as an LED can be used, the color gamut can be expanded and the saturation can be improved.
[0046] また、本発明の第 8の態様の導光板は、矩形状光射出面の一辺を含む側面に、そ の一辺に垂直な光入射面と、その光入射面から内部に入射する光を、一辺に向かい 合う対辺を含む側面側に反射させる傾斜面を含む光入射部を設けているので、光入 射面力も導光板の内部に入射した点状光源の光を、矩形状光射出面から効率よく出 射させることができる。このような導光板は、線状の光源を配置するための領域を設け る必要が無いので薄型化及び軽量ィ匕することができる。このような導光板もまた、液 晶パネルのノ ックライトユニットに用いられる導光板として最適である。 [0046] Further, the light guide plate of the eighth aspect of the present invention includes a light incident surface perpendicular to the one side including a side of the rectangular light exit surface, and light incident on the inside from the light incident surface. Is provided with a light incident part that includes an inclined surface that reflects to the side surface including the opposite side facing one side, so that the light from the point light source incident on the inside of the light guide plate is also emitted as a rectangular light. It can be projected efficiently from the surface. Such a light guide plate does not need to be provided with a region for arranging a linear light source, and thus can be made thinner and lighter. Such a light guide plate is also a liquid Ideal as a light guide plate used in crystal panel knocklight units.
[0047] また、本発明の第 9の態様の面状照明装置は、本発明の第 8の態様の導光板を備 えるので、装置の薄型化及び軽量ィ匕を実現することができ、また、 LEDなどの点状光 源を用いることができるので色再現性が高ぐ色再現域の拡大、彩度の向上を図るこ とがでさる。  [0047] Further, since the planar lighting device of the ninth aspect of the present invention includes the light guide plate of the eighth aspect of the present invention, the apparatus can be made thinner and lighter, and Since a point light source such as an LED can be used, it is possible to expand the color gamut and improve the saturation with high color reproducibility.
図面の簡単な説明  Brief Description of Drawings
[0048] [図 1]図 1Aは、本発明の面状照明装置を用いた液晶表示装置の概略斜視図であり， 図 1Bは、その概略断面図である。  FIG. 1A is a schematic perspective view of a liquid crystal display device using the planar illumination device of the present invention, and FIG. 1B is a schematic cross-sectional view thereof.
[図 2]図 2A及び図 2Bは、それぞれ、本発明に従う棒状照明装置の概略斜視図及び 概略側面図である。  FIG. 2A and FIG. 2B are a schematic perspective view and a schematic side view, respectively, of a rod-shaped lighting device according to the present invention.
[図 3]図 3は、導光体の下面の部分拡大断面図であり、導光体の下面に形成されてい るプリズムの様子を示す図である。  FIG. 3 is a partial enlarged cross-sectional view of the lower surface of the light guide, showing a state of the prism formed on the lower surface of the light guide.
[図 4]図 4は、ライトガイドを用いて LEDの光を導光体に導く様子を模式的に示した図 である。  [FIG. 4] FIG. 4 is a diagram schematically showing how the light of an LED is guided to a light guide using a light guide.
[図 5]図 5は、長さ方向に垂直な断面が円形で、端部から中央に向かって細くなる形 状の導光体の構成例である。  FIG. 5 is a structural example of a light guide having a circular cross section perpendicular to the length direction and narrowing from the end toward the center.
[図 6]図 6Aは、平行溝の断面形状が楕円の一部を取り除いたような形状を有する導 光板に導光体が収容されている様子の概略断面図であり、図 6B及び図 6Cは、それ ぞれ、その導光体の概略側面図及び概略斜視図である。  [FIG. 6] FIG. 6A is a schematic cross-sectional view showing a state in which the light guide is housed in a light guide plate having a shape in which the cross-sectional shape of the parallel grooves is such that a part of an ellipse is removed. These are a schematic side view and a schematic perspective view of the light guide, respectively.
[図 7]図 7A〜図 7Cは、一方の端面力 光を入射させるタイプの棒状照明装置に用 いられる導光体の構成例であり、図 7Aは、長さ方向に垂直な断面形状が三角形状 の場合の導光体であり、図 7Bは、長さ方向に垂直な断面形状が楕円の一部と取り除 いたような形状の場合の導光体であり、図 7Cは、長さ方向に垂直な断面形状が円形 の場合の導光体である。  [FIG. 7] FIGS. 7A to 7C are configuration examples of a light guide used in a bar-type lighting device of a type in which one end face force light is incident. FIG. 7A has a cross-sectional shape perpendicular to the length direction. Fig. 7B is a light guide when the cross-sectional shape perpendicular to the length direction is removed from a part of an ellipse, and Fig. 7C is a length of the light guide. This is a light guide when the cross-sectional shape perpendicular to the direction is circular.
[図 8]図 8は、平行溝を画成する壁面に相当する部分の線形状が双曲線の一部であ るような導光板の平行溝に導光体が収容されている様子を示す概略断面図である。  [FIG. 8] FIG. 8 is a schematic diagram showing a state in which the light guide is housed in the parallel groove of the light guide plate in which the linear shape of the portion corresponding to the wall surface defining the parallel groove is a part of a hyperbola. It is sectional drawing.
[図 9]図 9は、平行溝の断面形状が、平行溝の中心を通り導光板の光射出面に垂直 な中心線に対して対称な 2つの円弧曲線の一部力 形成されている導光板の概略 断面図である。 [FIG. 9] FIG. 9 shows a guide in which the cross-sectional shape of the parallel grooves is formed by partial forces of two circular arcs that are symmetrical with respect to the center line that passes through the center of the parallel grooves and is perpendicular to the light exit surface of the light guide plate. Outline of light plate It is sectional drawing.
[図 10]図 10は、平行溝の断面形状が、平行溝の中心を通り導光板の光射出面に垂 直な中心線に対して対称な 2つの放物線の一部力 形成されている導光板の概略 断面図である。  [FIG. 10] FIG. 10 shows that the cross-sectional shape of the parallel grooves is formed by partial force of two parabolas symmetrical with respect to the center line perpendicular to the light exit surface of the light guide plate through the center of the parallel grooves. It is a schematic sectional drawing of an optical plate.
[図 11]図 11は、平行溝の長さ方向に垂直な断面形状が、平行溝の中心に向力つて 凸の 2つの曲線力 形成されている導光板の概略断面図である。  [FIG. 11] FIG. 11 is a schematic cross-sectional view of a light guide plate in which a cross-sectional shape perpendicular to the length direction of the parallel grooves is formed with two curvilinear forces convex toward the center of the parallel grooves.
[図 12]図 12は、平行溝の長さ方向に垂直な断面形状が、平行溝の中心に向力つて 凸の曲線と凹の曲線を組み合わせた曲線力 形成されて 、る導光板の概略断面図 である。  [FIG. 12] FIG. 12 is a schematic view of a light guide plate in which a cross-sectional shape perpendicular to the length direction of the parallel grooves is formed by a curved force combining a convex curve and a concave curve directed toward the center of the parallel grooves. FIG.
[図 13]図 13は、導光板の光射出面側に形成される網点パターンの例である。  FIG. 13 is an example of a halftone dot pattern formed on the light exit surface side of the light guide plate.
[図 14]図 14は、複数並列して配置された導光板を用いた面状照明装置の概略断面 図である。  FIG. 14 is a schematic cross-sectional view of a planar illumination device using a plurality of light guide plates arranged in parallel.
圆 15]図 15Aは、発明の面状照明装置に用いられる導光板の傾斜背面と反射シート との間にプリズムシートが配置されている様子を示す概略断面図であり、図 15Bは、 反射シートと導光板の傾斜背面との間に配置されて 、るプリズムシートを導光板側か ら見た概略平面図、及び、そのプリズムシートの概略横断面図である。 15] FIG. 15A is a schematic cross-sectional view showing a state in which a prism sheet is arranged between the inclined back surface of the light guide plate used in the planar lighting device of the invention and the reflection sheet, and FIG. 15B is a reflection sheet. FIG. 2 is a schematic plan view of the prism sheet disposed between the light guide plate and the inclined rear surface of the light guide plate, and a schematic cross-sectional view of the prism sheet.
[図 16]図 16Aは、導光板の側面に反射板を配置した構成例であり、図 16Bは、導光 板を並列して配置したときに導光板の側面に反射板を配置した構成例である。 FIG. 16A is a configuration example in which a reflector is disposed on the side surface of the light guide plate, and FIG. 16B is a configuration example in which a reflector plate is disposed on the side surface of the light guide plate when the light guide plates are disposed in parallel. It is.
[図 17]図 17Aは、光ファイバを用いて導光板に光を入射させるタイプの面状照明装 置に用いられる導光板の模式的断面図である、図 17Bは、その導光板を背面側から 見た模式的下面図である。 FIG. 17A is a schematic cross-sectional view of a light guide plate used in a planar lighting device of a type in which light is incident on the light guide plate using an optical fiber. FIG. It is the typical bottom view seen from.
[図 18]図 18Aは、棒状の導光体 (第 2導光体)が平行溝に一体的に組み込まれた導 光板の模式的断面図であり、図 18Bは、その導光板を背面側から見た模式的下面 図である。  FIG. 18A is a schematic cross-sectional view of a light guide plate in which a rod-shaped light guide (second light guide) is integrated in a parallel groove, and FIG. 18B shows the light guide plate on the back side. It is the typical bottom view seen from.
[図 19]図 18Aおよび図 18Bに示した導光体の模式的斜視図である。  FIG. 19 is a schematic perspective view of the light guide shown in FIGS. 18A and 18B.
[図 20]図 20Aは、長さ方向に垂直な断面が楕円の一部を取り除いたような形状の平 行溝に導光体が収容された導光板の模式的断面図であり、図 20Bは、その導光板を 背面側から見た模式的下面図である。 [図 21]図 20Aおよび図 20Bに示した導光体の模式的斜視図である。 [FIG. 20] FIG. 20A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove shaped such that a part of an ellipse is removed from a cross section perpendicular to the length direction. FIG. 4 is a schematic bottom view of the light guide plate as viewed from the back side. FIG. 21 is a schematic perspective view of the light guide shown in FIGS. 20A and 20B.
[図 22]図 22Aは、長さ方向に垂直な断面が三角形状の平行溝に導光体が収容され ている導光板の模式的断面図であり、図 22Bは、その導光板を背面側から見た模式 的下面図である。 FIG. 22A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a triangular cross section perpendicular to the length direction, and FIG. 22B shows the light guide plate on the back side. It is the typical bottom view seen from.
[図 23]図 22A及び図 22Bに示した導光板に用いられ、一方の端面のみから光を入 射させる場合の導光体の模式的斜視図である。  FIG. 23 is a schematic perspective view of a light guide used in the light guide plate shown in FIGS. 22A and 22B when light is incident only from one end face.
[図 24]図 24Aは、長さ方向に垂直な断面が楕円の一部を取り除いたような形状の平 行溝に導光体が収容されている導光板の模式的断面図であり、図 24Bは、図 24Aに 示す導光板を背面側から見た模式的下面図である。  [FIG. 24] FIG. 24A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a cross section perpendicular to the length direction in which a part of an ellipse is removed. 24B is a schematic bottom view of the light guide plate shown in FIG. 24A as viewed from the back side.
[図 25]図 24A及び図 24Bに示した導光板の平行溝に収容され、一方の端面のみか ら光を入射させる導光体の模式的斜視図を示した。  FIG. 25 is a schematic perspective view of a light guide that is accommodated in the parallel grooves of the light guide plate shown in FIGS. 24A and 24B and allows light to enter only from one end face.
[図 26]図 26Aは、導光板 (第 1導光体)の平行溝に導光体 (第 2導光体)を設けずに、 導光板の端面力 光を入射させるタイプの面状照明装置に用いられる導光板の模式 的断面図であり、図 26Bは、図 26Aの導光板の B— B線矢視図であり、図 26Cは、図 26Aに示した導光板を背面側力も見た模式的下面図である。  [FIG. 26] FIG. 26A shows a surface illumination of a type in which the end face force light of the light guide plate is incident without providing the light guide (second light guide) in the parallel groove of the light guide plate (first light guide). 26B is a schematic cross-sectional view of the light guide plate used in the apparatus, FIG. 26B is a view taken along the line B-B of the light guide plate in FIG. 26A, and FIG. 26C is a view of the rear side force of the light guide plate shown in FIG. It is the typical bottom view.
圆 27]図 27A〜図 27Cは、第 2導光体を有しない面状照明装置に用いられる導光板 の別の構成例であり、図 27Aは、楕円の一部を取り除いたような断面形状を有する溝 が背面に形成された導光板の模式的断面図であり、図 27Bは、図 27Aに示した導光 板の B— B線矢視図であり、図 27Cは、図 27Aに示した導光板を背面側から見た模 式的下面図である。 27] FIGS. 27A to 27C are other examples of the light guide plate used in the planar lighting device that does not have the second light guide, and FIG. 27A is a cross-sectional shape in which a part of the ellipse is removed. FIG. 27B is a schematic cross-sectional view of the light guide plate formed on the back surface with a groove having a groove, FIG. 27B is a view taken along the line B-B of the light guide plate shown in FIG. 27A, and FIG. It is the typical bottom view which looked at the light guide plate seen from the back side.
[図 28]図 28Aは、一方の端面力 光を入射させるタイプの面状照明装置に用いられ 、溝の断面形状が V字状の導光板の模式的断面図であり、図 28Bは、図 28Aに示し た導光板の B— B線矢視図であり、図 28Cは、図 28Aに示した導光板を背面側から 見た模式的下面図である。  [FIG. 28] FIG. 28A is a schematic cross-sectional view of a light guide plate used in a planar lighting device of a type in which one end surface force light is incident, and the groove has a V-shaped cross-section, and FIG. FIG. 28C is a schematic bottom view of the light guide plate shown in FIG. 28A as viewed from the back side.
[図 29]図 29Aは、一方の端面力 光を入射させるタイプの面状照明装置に用いられ 、溝の断面形状が楕円の一部を切断したような U字状の導光板の模式的断面図であ り、図 29Bは、図 29Aに示した導光板の B—B線矢視図であり、図 29Cは、図 29Aに 示した導光板を背面側から見た模式的下面図である。 [図 30]図 30Aは、本発明の棒状照明装置を備えたタンデム方式の面状照明装置の 導光板の概略断面図であり、図 30Bは、その部分拡大断面図であり、図 30Cは、図 3 OBに示した導光板を、反射フィルムを取り除いた状態で背面側から見た模式的下面 図である。 [FIG. 29] FIG. 29A is a schematic cross-section of a U-shaped light guide plate used in a planar lighting device of the type in which one end face force light is incident and the cross-sectional shape of the groove is a part of an ellipse cut. 29B is a BB line arrow view of the light guide plate shown in FIG. 29A, and FIG. 29C is a schematic bottom view of the light guide plate shown in FIG. 29A viewed from the back side. . FIG. 30A is a schematic cross-sectional view of a light guide plate of a tandem planar lighting device provided with the rod-shaped lighting device of the present invention, FIG. 30B is a partially enlarged cross-sectional view thereof, and FIG. FIG. 3 is a schematic bottom view of the light guide plate shown in OB as seen from the back side with the reflective film removed.
[図 31]図 31Aは、図 5に示した形状の導光体を有するタンデム方式の面状照明装置 に用いられ、タンデム配置された複数の導光板の概略断面図であり、図 31Bは、その 部分拡大断面図であり、図 31Cは、図 31Bに示した導光板を、反射フィルムを除いた 状態で背面側から見た模式的下面図である。  FIG. 31A is a schematic cross-sectional view of a plurality of light guide plates arranged in tandem, which is used in a tandem planar lighting device having a light guide body having the shape shown in FIG. 5, and FIG. FIG. 31C is a partial enlarged cross-sectional view, and FIG. 31C is a schematic bottom view of the light guide plate shown in FIG. 31B as viewed from the back side with the reflection film removed.
[図 32]図 32Aは、一方の端部カゝら光が入射される、タンデム配置された複数の導光 板の概略断面図であり、図 32Bは、その部分拡大断面図であり、図 32Cは、図 32B に示した導光板を、反射フィルムを除 、た状態で背面側から見た模式的下面図であ る。  FIG. 32A is a schematic cross-sectional view of a plurality of light guide plates arranged in tandem, in which light is incident from one end portion, and FIG. 32B is a partially enlarged cross-sectional view thereof. 32C is a schematic bottom view of the light guide plate shown in FIG. 32B viewed from the back side with the reflection film removed.
[図 33]図 33Aは、一方の端部カゝら光が入射される、タンデム配置された複数の導光 板の図 32A〜図 32Cとは別の構成例の概略断面図であり、図 33Bは、その部分拡 大断面図であり、図 33Cは、図 33Bに示した導光板を、反射フィルムを除いた状態で 背面側から見た模式的下面図である。  FIG. 33A is a schematic cross-sectional view of a configuration example different from FIGS. 32A to 32C of a plurality of light guide plates arranged in tandem, in which light from one end portion is incident, 33B is a partially enlarged cross-sectional view, and FIG. 33C is a schematic bottom view of the light guide plate shown in FIG. 33B as viewed from the back side with the reflection film removed.
[図 34]図 34Aは、棒状照明装置を用いない面状照明装置に用いられる、タンデム配 置された複数の導光板の模式的断面図であり、図 34Bは、その部分拡大断面図であ り、図 34Cは、図 34Bに示した導光板を背面側力も見た模式的下面図である。  FIG. 34A is a schematic cross-sectional view of a plurality of tandem light guide plates used in a planar illumination device that does not use a rod-like illumination device, and FIG. 34B is a partially enlarged cross-sectional view thereof. FIG. 34C is a schematic bottom view of the light guide plate shown in FIG.
[図 35]図 35Aは、棒状照明装置を用いない面状照明装置に用いられる、タンデム配 置された複数の導光板の図 34A〜図 34Cとは別の構成例の模式的断面図であり、 図 35Bは、その部分拡大断面図であり、図 35Cは、図 35Bに示した導光板を背面側 から見た模式的下面図である。  FIG. 35A is a schematic cross-sectional view of a configuration example different from FIGS. 34A to 34C of a plurality of light guide plates arranged in tandem used in a planar lighting device that does not use a rod-like lighting device. FIG. 35B is a partially enlarged cross-sectional view thereof, and FIG. 35C is a schematic bottom view of the light guide plate shown in FIG. 35B as viewed from the back side.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0049] 以下、本発明の導光部材と、それを用いる面状照明装置、液晶表示装置及び本発 明の棒状照明装置について、添付の図面に示される好適な態様を基に、詳細に説 明する。 [0049] Hereinafter, the light guide member of the present invention, the planar illumination device using the same, the liquid crystal display device, and the rod-shaped illumination device of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings. Light up.
[0050] 図 1Aに、本発明の面状照明装置 (以下、ノ ックライトユニットともいう）を用いた液晶 表示装置の概略斜視図を示す。液晶表示装置 10は、基本的に、本発明の面状照明 装置 2と、この面状照明装置 2の光射出面側に配置される液晶表示パネル 4と、それ らを駆動する駆動ユニット 6とを有する。図 1Bには、バックライトユニットの概略断面図 を示した。本発明の面状照明装置 2は、液晶表示装置 10のバックライトユニットとして 用いられ、液晶表示パネル 4の背後から、液晶表示パネル 4の全面に均一な光を照 射するための面状照明装置であり、液晶表示パネル 4の画像表示面と略同一の光射 出面 (発光面)を有する。面状照明装置 2は、基本的には、棒状照明装置 12と、拡散 シート 14と、プリズムシート 16及び 17と、導光板 18と、リフレクタ 20と、反射板 22とを 備える。 [0050] FIG. 1A shows a liquid crystal using the planar illumination device of the present invention (hereinafter also referred to as a knock light unit). The schematic perspective view of a display apparatus is shown. The liquid crystal display device 10 basically includes a planar illumination device 2 of the present invention, a liquid crystal display panel 4 disposed on the light emission surface side of the planar illumination device 2, and a drive unit 6 that drives them. Have Fig. 1B shows a schematic cross-sectional view of the backlight unit. The planar illumination device 2 of the present invention is used as a backlight unit of the liquid crystal display device 10, and the planar illumination device for irradiating the entire surface of the liquid crystal display panel 4 with uniform light from behind the liquid crystal display panel 4. And has a light emission surface (light emission surface) substantially the same as the image display surface of the liquid crystal display panel 4. The planar illumination device 2 basically includes a rod-shaped illumination device 12, a diffusion sheet 14, prism sheets 16 and 17, a light guide plate 18, a reflector 20, and a reflection plate 22.
[0051] まず、図 1A及び図 1Bに示した面状照明装置 2に用いられている本発明の棒状照 明装置 12について説明する。図 2A及び図 2Bに、それぞれ、本発明に従う棒状照明 装置 12の概略斜視図及び概略側面図を示す。  [0051] First, the rod-like illumination device 12 of the present invention used in the planar illumination device 2 shown in Figs. 1A and 1B will be described. FIG. 2A and FIG. 2B show a schematic perspective view and a schematic side view of the rod-shaped lighting device 12 according to the present invention, respectively.
[0052] 棒状照明装置 12は、図 2A及び図 2Bに示すように、導光体 32と、点状光源として の一組の発光ダイオード（LED) 34A、 34Bとを主に有する。図 2A及び図 2Bに示し た棒状照明装置 12は、図 1A及び図 1Bに示すような平行溝 18fの断面が三角形状 の導光板 18に用いられるものであり、図 2A及び図 2Bにおける導光体 32は、それぞ れ、導光板 18の平行溝 18fに収容されるような三角柱状の外形を有する。すなわち、 本発明の棒状照明装置 12に用いられる導光体 32は、その長さ方向に垂直な面で切 断したときの断面形状が、導光板 18の平行溝 18fの断面形状と略同形又は相似形 の三角形形状を有している。また、それぞれの導光体 32は、両端面 33aから中央に 向かうに従って次第に断面積が小さくなるように形成されている。ここでは、導光体 3 2が導光板 18の平行溝 18fに収容された場合に、導光板 18と対面しない側の面、す なわち、導光体 32の下面 33bのみを傾斜するように、導光体 32が構成されている。 また、導光体 32は、図示例では、 1組の透明体 33A及び 33Bを用いて構成されて いる。それぞれの透明体 33A及び 33Bは、その断面が三角形状で、一方の端面 33 aから他方の端面 33bに向かうに従って断面積が次第に小さくなるような形状を有す る。また、それぞれの透明体 33A及び 33Bの断面積の小さい側の端面 33b同士が 互 ヽに密着するように同軸に連結されて導光体 32が構成されて ヽる。 [0053] 棒状照明装置 12において、 LED34A及び 34Bは、図 2A及び図 2Bに示すように、 導光体 32の両端面 33aにそれぞれ配置される。 LED34A及び 34Bは、駆動ュ-ッ ト 6と接続されている。 LED34A及び 34Bからの光は、それぞれ、導光体 32A及び 3 2Bの端面 33aから内部に入射される。前述したように導光体 32の下面 33bは傾斜し ており、これにより、導光体 32の両端面 33aから入射した光の一部力 下面 33bで反 射して図 2B中上方に向力うとともに、下面 33b以外の側面で屈折した後、導光体 32 の側壁面から外部に出射する。 [0052] As shown in FIGS. 2A and 2B, the rod-shaped lighting device 12 mainly includes a light guide 32 and a pair of light emitting diodes (LEDs) 34A and 34B as point light sources. 2A and 2B is used for the light guide plate 18 having a triangular cross section of the parallel groove 18f as shown in FIGS. 1A and 1B, and the light guide plate in FIGS. 2A and 2B. Each of the bodies 32 has an outer shape of a triangular prism that is accommodated in the parallel groove 18f of the light guide plate 18. That is, the light guide 32 used in the rod-shaped illuminating device 12 of the present invention has a cross-sectional shape that is substantially the same as the cross-sectional shape of the parallel grooves 18f of the light guide plate 18 when cut along a plane perpendicular to the length direction thereof. It has a similar triangular shape. Each light guide 32 is formed such that the cross-sectional area gradually decreases from the both end faces 33a toward the center. Here, when the light guide 32 is accommodated in the parallel groove 18f of the light guide plate 18, the surface on the side that does not face the light guide plate 18, that is, the lower surface 33b of the light guide 32 is inclined only. A light guide 32 is formed. In the illustrated example, the light guide 32 is configured using a pair of transparent bodies 33A and 33B. Each of the transparent bodies 33A and 33B has a triangular cross section, and has a shape such that the cross-sectional area gradually decreases from one end face 33a toward the other end face 33b. Further, the light guide 32 is configured by coaxially connecting the end faces 33b on the side having a smaller cross-sectional area of each of the transparent bodies 33A and 33B so as to be in close contact with each other. [0053] In the rod-shaped lighting device 12, the LEDs 34A and 34B are respectively disposed on both end surfaces 33a of the light guide 32 as shown in FIGS. 2A and 2B. The LEDs 34A and 34B are connected to the drive boot 6. Light from the LEDs 34A and 34B is incident on the inside from the end faces 33a of the light guides 32A and 32B, respectively. As described above, the lower surface 33b of the light guide 32 is inclined, so that a partial force of light incident from both end surfaces 33a of the light guide 32 is reflected by the lower surface 33b and directed upward in FIG. 2B. In addition, after being refracted on the side surface other than the lower surface 33b, the light is emitted from the side wall surface of the light guide 32 to the outside.
[0054] ここで、図 2A及び図 2Bに示す導光体 32においては、その下面 33bにプリズム列 が形成されることが好ましい。図 3に、導光体 32の下面 33bにプリズム 36が列状に形 成されている様子を部分的に示した。図 3に示すように、プリズム 36は、導光体 32の 長さ方向に対して垂直に延在して形成される。このようなプリズム 36の列を導光体 32 の下面 33bに形成することにより、導光体 32の端面力もコリメートされた光束を入射さ せたときに、そのコリメートされた光束力 順次導光体の全長方向に対し、ほぼ垂直 に立ち上がるので、導光体 32の側面から出射する光の該導光体全長方向における 光量分布を均一にすることができる。また、プリズム 36のそれぞれの形状は任意の形 状にすることができ、頂角力 5° のプリズムであることが好ましい。頂角力 5° のプリ ズムとすることにより、導光体 32の端面力もコリメートされた光束を入射させたときに、 そのコリメートされた光束がプリズムの斜面に入射し、全反射した際にほぼ垂直に立 ち上がるので、導光体 32の側面から出射する光の該導光体全長方向における光量 分布をより一層均一にすることができる。  Here, in the light guide 32 shown in FIGS. 2A and 2B, a prism row is preferably formed on the lower surface 33b. FIG. 3 partially shows a state in which the prisms 36 are formed in a row on the lower surface 33 b of the light guide 32. As shown in FIG. 3, the prism 36 is formed to extend perpendicular to the length direction of the light guide 32. By forming such a row of prisms 36 on the lower surface 33b of the light guide 32, the collimated light flux is sequentially applied to the collimated light when the end face force of the light guide 32 is also collimated. Therefore, the light quantity distribution of the light emitted from the side surface of the light guide 32 in the light guide full length direction can be made uniform. Each shape of the prism 36 can be any shape, and is preferably a prism having an apex angle force of 5 °. By adopting a prism with an apex angle force of 5 °, when the collimated light beam is also incident on the end face force of the light guide 32, the collimated light beam is incident on the slope of the prism and is almost vertical when totally reflected. Therefore, the light quantity distribution of the light emitted from the side surface of the light guide 32 in the entire length direction of the light guide can be made more uniform.
[0055] 導光体 32は、透明な榭脂から形成することができる。また、製造方法としては、例え ば、加熱した原料榭脂を、押し出し成形や射出成形によって成形する方法、型中で モノマー、オリゴマー等を重合させて成形する注形重合法等を用いることができる。 導光体 18の材料としては、例えば、ポリカーボネートや PMMA (ポリメチルメタクリレ ート）などのアクリル系榭脂、 PET (ポリエチレンテレフタレート）、 PP (ポリプロピレン） 、 PC (ポリカーボネート）、 PMMA (ポリメチノレメタタリレート）、ベンジノレメタタリレート や MS榭脂、その他のアクリル系榭脂、あるいは COP (シクロォレフィンポリマー）など の透明榭脂を用いることができる。透明樹脂には、光を散乱させるための微粒子を混 入させても良ぐこれにより側壁からの光の出射効率を一層高めることができる。 [0055] The light guide 32 can be formed of a transparent resin. In addition, as a production method, for example, a method of molding heated raw material resin by extrusion molding or injection molding, a casting polymerization method in which a monomer, an oligomer, or the like is polymerized and molded in a mold can be used. . Examples of the material of the light guide 18 include acrylic resin such as polycarbonate and PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), and PMMA (polymethylolene). Tatalylate), benzenoremetatalylate, MS resin, other acrylic resins, or transparent resins such as COP (cycloolefin polymer) can be used. Transparent resin is mixed with fine particles to scatter light. The light emission efficiency from the side wall can be further increased.
[0056] なお、ここでは、図 2A及び図 2Bに示すように、導光体 32を 2つの透明体 33A及び 33Bから構成したが、一体で導光体を構成しても良い。導光体 32を一つの部材で構 成する場合は、一方の端部から中央に向かうに従って断面積が小さくなるように透明 体を加工すればよい。図示例のように、一方の端部から他方の端部に向かうに従つ て断面積が小さくなるような形状のほうが、加工が容易であるので、このような形状を 有する 2つの透明体を連結して導光体を構成したほうが、製造コストを低く抑えること ができるという利点がある。  [0056] Here, as shown in FIGS. 2A and 2B, the light guide 32 is composed of two transparent bodies 33A and 33B, but the light guide may be integrally formed. When the light guide 32 is composed of one member, the transparent body may be processed so that the cross-sectional area decreases from one end toward the center. As shown in the example in the figure, the shape with a smaller cross-sectional area as it goes from one end to the other end is easier to process, so two transparent bodies having such a shape are Combining the light guides together has the advantage that the manufacturing cost can be kept low.
[0057] 図 2A及び図 2Bにおいて、本発明の棒状照明装置 12を構成する発光ダイオード（ LED) 34Aは、例えば、高輝度 LEDを用いて構成することができ、 RGB— LEDや白 色 LEDを用いて構成することが好ましい。これら以外にも白熱灯や豆電球も用い得 る。  In FIG. 2A and FIG. 2B, the light emitting diode (LED) 34A constituting the rod-shaped lighting device 12 of the present invention can be configured using, for example, a high-intensity LED, such as an RGB-LED or a white LED. It is preferable to use it. In addition to these, incandescent and miniature bulbs can also be used.
LED34A及び 34Bとして RGB— LEDを用いる場合は、 RGBを順次パルス点灯す ることが好ましい。このようにパルス点灯させることにより、消費電力を低減することが できる。このように RGB— LEDの R、 G、 Bのそれぞれの LEDを順次点灯させる場合 においては、数 msec以下の AC (交流）点灯で順次点灯させることが好ましぐこのよ うな周期で点灯させれば、それら光は、人間の目には、その応答性から、 R、 G及び B のそれぞれの LEDからの光が積分されて、直流点灯させた場合と同じように見える。 更に、このように順次点灯させれば、液晶パネルのバックライトとして利用した際に、 液晶パネルに RGBのフィルタが必要なくなるので、フィルタのある場合に比較して約 2倍程度に輝度を向上させることができる。  When RGB-LEDs are used as the LEDs 34A and 34B, it is preferable to sequentially turn on the RGB pulses. By turning on pulses in this way, power consumption can be reduced. In this way, when R, G, and B of the RGB-LEDs are turned on sequentially, it is preferable to turn them on sequentially with AC (alternating current) lighting of several milliseconds or less. For example, these lights appear to the human eye in the same way as when the lights from the R, G, and B LEDs are integrated and lit by direct current because of their responsiveness. Furthermore, if it is turned on sequentially in this way, when it is used as a backlight for a liquid crystal panel, the LCD panel does not require an RGB filter, so the brightness is improved by a factor of about 2 compared to the case with a filter. be able to.
[0058] 図 2A及び図 2Bに示した棒状照明装置 12においては、 LED34A及び 34Bを導光 体 32の両端面 33aに配置した構成にした力 図 4に示すように、 LED34A及び 34B を一箇所にまとめて配置し、それぞれの LED34A及び 34B力も発せられた光を、ラ イトガイド 38A及び 38Bを用いて導光体 32の端面に導いてもよい。例えば、図 4に示 したように、複数の導光板を配置して光射出面を大きくして面状照明装置を構成した 場合に、それぞれの導光板の平行溝に配置される導光体の端部と、それぞれの導光 体に対応する LEDの光出射部との間にそれぞれ追加の導光部材であるライトガイド 38を配置し、 LEDの光を、ライトガイドを介して導光体の端部に入光させるように構 成しても良い。 [0058] In the rod-like lighting device 12 shown in FIGS. 2A and 2B, the LEDs 34A and 34B are arranged at one end as shown in FIG. Alternatively, the light that is also emitted from the LEDs 34A and 34B may be guided to the end face of the light guide 32 using the light guides 38A and 38B. For example, as shown in FIG. 4, when a planar illumination device is configured by arranging a plurality of light guide plates to increase the light emission surface, the light guides arranged in the parallel grooves of the respective light guide plates are arranged. Light guides, which are additional light guide members, between the end portions and the light emitting portions of the LEDs corresponding to the respective light guides 38 may be arranged so that the light of the LED enters the end of the light guide through the light guide.
このようなライトガイド 38は、例えば、光ファイバと矩形導光路を組み合わせて構成 することができる。 LED34を導光体 32の端面近傍に配置した場合は、 LED34の発 熱により導光体 32が変形したり、溶融する恐れがあるが、このようなライトガイド 38を 用いることにより、 LED34の発熱による導光体 32の変形及び溶融を防止することが できる。ここで、矩形導光路は、上述した透明体と同様に、透明な榭脂材料を用いて 構成することができる。なお、以降の構成例については、この追加の導光部材である ライトガイドの例として光ファイバを用いたものを例示する。  Such a light guide 38 can be configured by combining an optical fiber and a rectangular light guide, for example. If the LED 34 is disposed near the end face of the light guide 32, the light guide 32 may be deformed or melted by the heat generated by the LED 34. By using such a light guide 38, the LED 34 generates heat. It is possible to prevent the light guide 32 from being deformed and melted by the above. Here, the rectangular light guide can be configured using a transparent resin material in the same manner as the transparent body described above. In addition, about the subsequent structural example, what uses an optical fiber is illustrated as an example of the light guide which is this additional light guide member.
[0059] 以上説明したように、本発明の棒状照明装置の導光体は、面状照明装置の導光板 の平行溝に収容されて利用される。従来の冷陰極管を用いた面状照明装置の場合 は、典型的な冷陰極管は円柱状の形状を有していたため、冷陰極管から放射される 光を確実に且つ効率よく導光板の内部に取り込むために、冷陰極管を平行溝に確 実に収容しなければならな力つた。このため、導光板を薄型にするのが困難であった 。し力しながら、本発明の面状照明装置は、導光板の平行溝の外形と略同じ外形に なるように、棒状照明装置の導光体を加工しているので、使用する光源の外形に依 存することなく面状照明装置全体を薄型化することができる。  [0059] As described above, the light guide of the rod-shaped illumination device of the present invention is accommodated and used in the parallel groove of the light guide plate of the planar illumination device. In the case of a conventional planar lighting device using a cold cathode tube, a typical cold cathode tube has a cylindrical shape, so that light emitted from the cold cathode tube can be reliably and efficiently emitted from the light guide plate. In order to capture the inside, the cold cathode tube had to be securely housed in the parallel groove. For this reason, it has been difficult to make the light guide plate thin. However, in the planar illumination device of the present invention, the light guide body of the rod-like illumination device is processed so that it has substantially the same outer shape as the parallel groove of the light guide plate. The entire planar lighting device can be made thin without relying on it.
[0060] 本発明者の知見によれば、図 1 A及び図 1Bに示すような平行溝を光入光部とする 導光板を用いた面状照明装置においては、導光板の平行溝の形状を変更すること によって平行溝の直上における輝線の発生を抑制することができる。それゆえ、導光 板 18の平行溝 18fの形状に合わせて棒状照明装置 12の導光体 32の外形を加工す ることにより、導光板 18の光射出面 18aにおける輝線の発生を抑制しつつ、従来の 冷陰極管を用いた場合よりも更に薄型化した面状照明装置を構成することができる。  According to the knowledge of the present inventor, in a planar illumination device using a light guide plate having a parallel groove as shown in FIGS. 1A and 1B as a light incident portion, the shape of the parallel groove of the light guide plate By changing, generation of bright lines immediately above the parallel grooves can be suppressed. Therefore, by processing the outer shape of the light guide 32 of the rod-like lighting device 12 in accordance with the shape of the parallel grooves 18f of the light guide plate 18, the generation of bright lines on the light exit surface 18a of the light guide plate 18 is suppressed. Thus, it is possible to configure a planar illumination device that is thinner than when a conventional cold cathode tube is used.
[0061] つぎに、棒状照明装置の導光体の上記実施形態とは異なる構成例について説明 する。図 5には、長さ方向に垂直な断面が円形で、端部から中央に向かって細くなる 形状の導光体の例を示した。図 5に示した導光体 52は、 1組の透明な円錐台状の透 明体 53A及び 53Bを、その断面の小さな端面同士が互いに密着するように連結して 構成されている。このような導光体 52は、例えば、長さ方向に垂直な断面が半円形 状の平行溝を有する導光板に用いられる。 Next, a configuration example different from that of the above-described embodiment of the light guide body of the rod-shaped lighting device will be described. Fig. 5 shows an example of a light guide having a circular cross section perpendicular to the length direction and narrowing from the end toward the center. The light guide 52 shown in FIG. 5 is configured by connecting a pair of transparent frustoconical transparent bodies 53A and 53B so that the end faces with small cross sections are in close contact with each other. Such a light guide 52 has, for example, a semicircular cross section perpendicular to the length direction. It is used for a light guide plate having a parallel groove.
図 5に示した形状を有する導光体は、 LEDなどに代表される点状光源を前記棒状 導光体により棒状光源に変換し、前記平板状導光体の凹部に前記棒状導光体を埋 め込むことにより、棒状照明を面状照明に変換し、液晶ノ ックライトユニットとして用い ることが可能になる。  The light guide having the shape shown in FIG. 5 converts a point light source typified by an LED or the like into a rod light source by the rod light guide, and the rod light guide is placed in a recess of the flat light guide. By embedding, it becomes possible to convert the bar-shaped illumination into a planar illumination and use it as a liquid crystal knock light unit.
[0062] また、図 6A〜図 6Cには、棒状照明装置の導光体の更に異なる構成例を示した。  [0062] Further, FIGS. 6A to 6C show further different configuration examples of the light guide of the rod-shaped lighting device.
図 6Aは、平行溝 18fの断面形状が楕円の一部を取り除いたような形状を有する導光 板 18に導光体 62が収容されている様子の概略断面図であり、図 6Bは、その導光体 62の概略側面図、図 6Cは、導光体 62の概略斜視図である。図 6B及び図 6Cに示 すように、導光体 62は、長さ方向に対して垂直な断面の形状が、楕円の一部を取り 除いたような形状を有している。導光体 62は、 2つの透明体 63A及び 63B力も構成 されている。透明体 63A及び 63Bは、楕円柱を、その中心軸に対して所定の角度を 有し且つ楕円の長軸に対して垂直な平面で切断することにより得られるような形状を 有する。このような透明体 63A及び 63Bの断面積の小さい方の端面同士を連結する ことによって導光体 62が構成されている。このような形状の導光体 62は、図 6Aに示 すように、平行溝 18fの断面形状が楕円形の一部で形成されている導光板 18の平 行溝 18fに収容された形態で用いられる。そして、図 6Aに示すように、導光板 18の 傾斜面の下方に反射板 22が配置され、平行溝 18fに導光体 62を収容した状態で、 平行溝 18fを塞ぐようにリフレクタ 20が配置される。図 6A〜図 6Cに示した導光体に おいては、下面にプリズムを形成することもできる。  FIG. 6A is a schematic cross-sectional view showing a state in which the light guide 62 is accommodated in the light guide plate 18 having a shape in which the cross-sectional shape of the parallel groove 18f is a part of the ellipse is removed. FIG. FIG. 6C is a schematic perspective view of the light guide 62. FIG. As shown in FIG. 6B and FIG. 6C, the light guide 62 has a shape in which a cross-sectional shape perpendicular to the length direction is obtained by removing a part of an ellipse. The light guide 62 also includes two transparent bodies 63A and 63B force. The transparent bodies 63A and 63B have such a shape that is obtained by cutting the elliptic cylinder at a plane having a predetermined angle with respect to the central axis and perpendicular to the long axis of the ellipse. The light guide body 62 is configured by connecting the end faces having the smaller cross-sectional areas of the transparent bodies 63A and 63B. As shown in FIG. 6A, the light guide 62 having such a shape is accommodated in the parallel groove 18f of the light guide plate 18 in which the cross-sectional shape of the parallel groove 18f is formed as a part of an ellipse. Used. Then, as shown in FIG. 6A, the reflector 22 is disposed below the inclined surface of the light guide plate 18, and the reflector 20 is disposed so as to close the parallel groove 18f in a state where the light guide 62 is accommodated in the parallel groove 18f. Is done. In the light guide shown in FIGS. 6A to 6C, a prism can be formed on the lower surface.
[0063] 図 6A〜図 6Cに示した形状を有する導光体は、 LEDに代表される点状光源を、棒 状導光体を用いることにより線状光源に変換し、液晶バックライトユニットの線状光源 として用いられている CCFL (Cold Cathode Fluorescent Lamp：冷陰極管放電灯）の 代替光源として用いることが可能になる。  [0063] The light guide having the shape shown in FIGS. 6A to 6C converts a point light source typified by an LED into a linear light source by using a rod-shaped light guide. It can be used as an alternative light source for CCFL (Cold Cathode Fluorescent Lamp) used as a linear light source.
図 5及び図 6A〜図 6Cに示した導光体は、 2つの透明体を連結することにより構成 されている力 一体として構成されていても良い。  The light guides shown in FIG. 5 and FIGS. 6A to 6C may be configured as an integral force formed by connecting two transparent bodies.
[0064] 以上、図 1A及び図 1Bに示す面状照明装置 2に用いられる本発明の棒状照明装 置 12について詳細に説明した力 本発明はこれに限定されない。例えば、棒状照明 装置を構成する導光体の形状は、上記例に限定されず、面状照明装置を構成する 後述する導光板の平行溝の形状に応じて種々の形状に変更することができる。 また、 1つの LED光源でも十分に光量を確保できる場合は、導光体 32の一方の端 面にのみ LED光源を配置し、その端面のみ力 LED光源の光を入射するように構 成しても良い。この場合は、導光体 32を 2つの透明体を組み合わせて構成するので はなぐ導光板の平行溝内を略一様に光照射することができるような形状の 1つの透 明部材を用いて構成すればょ 、。 [0064] As described above, the force described in detail for the bar-shaped lighting device 12 of the present invention used in the planar lighting device 2 shown in Figs. 1A and 1B. The present invention is not limited to this. For example, bar lighting The shape of the light guide constituting the device is not limited to the above example, and can be changed to various shapes according to the shape of the parallel grooves of the light guide plate which constitutes the planar illumination device described later. In addition, if a single LED light source can secure a sufficient amount of light, an LED light source is arranged only on one end surface of the light guide 32, and the light from the LED light source is configured to be incident only on that end surface. Also good. In this case, since the light guide 32 is configured by combining two transparent bodies, a single transparent member having a shape capable of irradiating light substantially uniformly in the parallel groove of the light guide plate is used. If configured, ...
[0065] このように、 1つの透明部材を用いて形成された導光体の一方の端面力 LED光 源の光を入射させる棒状照明装置の構成例を図 7A、図 7B及び図 7Cにそれぞれ示 した。図 7A〜図 7Cに示した各図において、紙面左側の図は導光体の模式的側面 図であり、紙面右側の図は導光体の長さ方向に垂直な断面の模式図である。 [0065] In this manner, examples of the configuration of the rod-shaped illumination device that makes the light of one end surface force LED light source of the light guide formed using one transparent member incident are shown in FIGS. 7A, 7B, and 7C, respectively. Indicated. 7A to 7C, the left side of the drawing is a schematic side view of the light guide, and the right side of the drawing is a schematic view of a cross section perpendicular to the length direction of the light guide.
図 7Aに示した棒状照明装置の導光体 74は、長さ方向に対して垂直な方向の断面 形状が三角形状であり、 LED34の光が入射する一方の端面 (大径側端面という） 74 bから他方の端面 (小径側端面という） 74cに向かうに従って、断面積が次第に小さく なる構造を有する。図示例では、導光体 74の大径側端面 74bから小径側端面 74c に向力 方向にぉ 、て、導光体 74の下面 74aが上方に向力つて傾斜するように形成 されている。また、この導光体 74の下面 74aにはプリズム列が形成されている。このよ うな構造を有する導光体 74においては、導光体 74の大径側端面 74bから入射する LED34からの光は、下面 74aのプリズム列において反射した後、導光体 74の側面 力 外部に出射する。  The light guide 74 of the rod-shaped illumination device shown in FIG. 7A has a triangular cross-sectional shape in a direction perpendicular to the length direction, and one end face (referred to as a large-diameter side end face) on which light from the LED 34 enters 74 The cross-sectional area gradually decreases from b toward the other end face (referred to as the end face on the small diameter side) 74c. In the illustrated example, the lower surface 74a of the light guide 74 is formed so as to incline upward from the large diameter side end surface 74b of the light guide 74 toward the small diameter side end surface 74c. A prism row is formed on the lower surface 74 a of the light guide 74. In the light guide 74 having such a structure, the light from the LED 34 incident from the large-diameter end surface 74b of the light guide 74 is reflected by the prism row on the lower surface 74a, and then the side force of the light guide 74 is external. To exit.
[0066] また、図 7Bに示した棒状照明装置の導光体 76は、長さ方向に対して垂直な方向 の断面形状が楕円の一部を取り除いたような形状を有し、 LED光が入射する大径側 端面 76bから小径側端面 76cに向かうに従って、断面積が次第に小さくなる構造を 有する。このような導光体 76は、例えば、透明な楕円柱を、その中心軸に対して所定 の角度を有し、且つ、楕円の長軸に対して垂直な平面で切断することによって得られ る。このような構造を有する導光体 76においても、その下面 76aにプリズム列を形成 することができる。  [0066] In addition, the light guide 76 of the rod-shaped illuminating device shown in FIG. 7B has a shape in which a cross-sectional shape in a direction perpendicular to the length direction is a part of an ellipse, and LED light is emitted from the light guide 76. The cross-sectional area gradually decreases from the incident large-diameter side end surface 76b toward the small-diameter side end surface 76c. Such a light guide 76 can be obtained, for example, by cutting a transparent elliptic cylinder at a predetermined angle with respect to its central axis and a plane perpendicular to the major axis of the ellipse. . Even in the light guide 76 having such a structure, a prism row can be formed on the lower surface 76a.
[0067] また、図 7Cに示した棒状照明装置の導光体 78は、長さ方向に対して垂直な方向 の断面形状が円形で、 LED光が入射する大径側端面 78bから他方の小径側端面 7 8cに向かうに従って、次第に細くなる形状を有する。すなわち、図に示した棒状照明 装置の導光体は、細長い円錐台形状 (コーン形状)を有している。このような構造の 導光体 78を用いた場合も、大径側端面 78bから入射した LED光を、導光体 78の側 面から出射させることができる。 [0067] In addition, the light guide 78 of the rod-shaped lighting device shown in FIG. 7C has a direction perpendicular to the length direction. The cross-sectional shape is circular, and the shape gradually becomes thinner from the large-diameter side end surface 78b on which the LED light is incident toward the other small-diameter side end surface 78c. That is, the light guide of the rod-shaped lighting device shown in the figure has an elongated truncated cone shape (cone shape). Even when the light guide 78 having such a structure is used, the LED light incident from the large-diameter end face 78b can be emitted from the side face of the light guide 78.
[0068] 図 7A〜図 7Cに示した導光体 74、 76及び 78においては、大径側端面 74b、 76b 及び 78bのみ力も LED光を入射させるため、それら導光体 74、 76及び 78の内部を 通過した LEDからの光の一部力 その反対側の小径側端面 74c、 76c及び 78cに到 達することになる。このような LEDからの光を、その小径側端面 74c、 76c及び 78cに おいて反射させて、再度導光体の内部に入射させるために、その端面 74c、 76c及 び 78cを鏡面にカ卩ェしたり、小径側端面 74c、 76c及び 78cを覆うような反射板を設 けてもよい。 [0068] In the light guides 74, 76, and 78 shown in FIGS. 7A to 7C, only the large-diameter-side end faces 74b, 76b, and 78b cause the LED light to enter, so that the light guides 74, 76, and 78 The partial force of the light from the LED that has passed through the inside reaches the opposite end face 74c, 76c and 78c on the small diameter side. In order to reflect light from such an LED on the small-diameter side end faces 74c, 76c and 78c and to make it enter the light guide again, the end faces 74c, 76c and 78c are mirrored. Or a reflecting plate that covers the small-diameter side end faces 74c, 76c, and 78c.
[0069] 以上、一方の端面から LED光源の光を入射させる棒状照明装置の導光体につい て説明したが、そのような導光体の形状としては、上記形状に限定されず、導光体の 端面力 入射した光を導光体の側面から出射させることができれば任意の形状にす ることがでさる。  As described above, the light guide of the rod-like illumination device that makes the light of the LED light source incident from one end face has been described. However, the shape of such a light guide is not limited to the above shape, and the light guide If the incident light can be emitted from the side surface of the light guide, it can be formed into an arbitrary shape.
[0070] つぎに、この面状照明装置 2に用いられる構成部品のうち、上記棒状照明装置以 外の構成部品について図 1 A及び図 1Bを参照して詳細に説明する。  [0070] Next, among the components used in the planar illumination device 2, components other than the rod illumination device will be described in detail with reference to FIGS. 1A and 1B.
まず、導光板 18について説明する。図 1Bに示すように、導光板 18は、矩形状の光 射出面 18aと、その一辺に平行な一対の厚肉部 18bと、この厚肉部 18bの両側に前 記一辺に平行に形成される薄肉端部 18cと、厚肉部 18bから前記一辺に直交する方 向に両側の薄肉端部 18cに向かって肉厚が薄くなり、傾斜背面 18dを形成する傾斜 背面部 18eと、肉厚部 18bに前記一辺に平行に形成される、導光体 32を収納するた めの平行溝 18fとを有する。すなわち、導光板 18は、表面の外形形状が矩形状の板 状部材であり、透明榭脂により形成されている。導光板 18の光射出面 18aは平坦で あり、その反対側の面が、一方の辺に向力うにしたがって板厚が薄くなるように、光射 出面 18aに対して傾斜している。このように、導光板 18は、平行溝 18fの中心軸を含 み且つ光射出面 18aに垂直な面に対して対称な 1対の傾斜背面 18dを有し、この傾 斜背面 18dは、それぞれ、両側の薄肉端部 18cに向かうに従って肉厚が薄くなるよう に光射出面 18aに対して傾斜している。 First, the light guide plate 18 will be described. As shown in FIG. 1B, the light guide plate 18 is formed in parallel to the one side on both sides of the rectangular light emitting surface 18a, a pair of thick portions 18b parallel to one side thereof, and the thick portion 18b. The thin-walled end 18c and the thick-walled portion 18b are thinned toward the thin-walled end portions 18c on both sides in the direction perpendicular to the one side, and the inclined back-surface portion 18e and the thick-walled portion are formed. 18 b has a parallel groove 18 f formed in parallel to the one side for accommodating the light guide 32. That is, the light guide plate 18 is a plate-like member having a rectangular outer shape on the surface, and is formed of a transparent resin. The light exit surface 18a of the light guide plate 18 is flat, and the surface on the opposite side is inclined with respect to the light exit surface 18a so that the plate thickness becomes thinner toward the one side. Thus, the light guide plate 18 has a pair of inclined back surfaces 18d including the central axis of the parallel grooves 18f and symmetric with respect to a plane perpendicular to the light exit surface 18a. The oblique rear surfaces 18d are inclined with respect to the light exit surface 18a so that the thickness decreases toward the thin end portions 18c on both sides.
図 1A及び図 1Bに示す導光板 18は、本発明に従う導光部材の第 1導光体に相当 し、また、導光板の平行溝に収容される導光体が本発明に従う導光部材の第 2導光 体に相当する。  1A and 1B corresponds to the first light guide of the light guide member according to the present invention, and the light guide housed in the parallel groove of the light guide plate of the light guide member according to the present invention. Corresponds to the second light guide.
[0071] 図 1Bに示す構造を有する導光板 18において、その平行溝 18fに配置された導光 体から出射する光のうち、平行溝 18fの壁面力も導光板 18の内部に入射した光は、 導光板 18の背面 18dで反射した後、光射出面 18aから出射する。このとき、導光板 1 8の傾斜背面 18dから一部の光が漏出する場合もあるが、その漏出した光は、導光 板 18の傾斜背面 18d側に形成された反射シート 18で反射して再び導光板 18の内 部に入射し、光射出面 18aから出射する。  In the light guide plate 18 having the structure shown in FIG. 1B, out of the light emitted from the light guide arranged in the parallel groove 18f, the light whose wall force of the parallel groove 18f is also incident on the inside of the light guide plate 18 is After being reflected by the back surface 18d of the light guide plate 18, it is emitted from the light exit surface 18a. At this time, some light may leak from the inclined back surface 18d of the light guide plate 18. However, the leaked light is reflected by the reflection sheet 18 formed on the inclined back surface 18d side of the light guide plate 18. The light again enters the light guide plate 18 and exits from the light exit surface 18a.
[0072] 本発明において、導光板 18は、例えば、加熱した原料榭脂を、押し出し成形や射 出成形によって成形する方法、型中でモノマー、オリゴマー等を重合させて成形する 注形重合法等を用いて製造することができる。導光板 18の材料としては、例えば、ポ リカーボネートや PMMA (ポリメチルメタタリレート）などのアクリル系榭脂、 PET (ポリ エチレンテレフタレート）、 PP (ポリプロピレン）、 PC (ポリカーボネート）、 PMMA (ポリ メチルメタタリレート）、ベンジルメタタリレートや MS榭脂、その他のアクリル系榭脂、あ るいは COP (シクロォレフィンポリマー）などの透明榭脂を用いることができる。透明榭 脂には、光を散乱させるための微粒子を混入させても良ぐこれにより光射出面から の光の出射効率を一層高めることができる。  [0072] In the present invention, the light guide plate 18 is formed by, for example, a method in which heated raw material resin is molded by extrusion molding or injection molding, a casting polymerization method in which monomers, oligomers, and the like are molded in a mold. Can be used. Examples of the material of the light guide plate 18 include acrylic resin such as polycarbonate and PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), PMMA (polymethyl). Metatalylate), benzyl metatalylate, MS resin, other acrylic resins, or transparent resins such as COP (cycloolefin polymer) can be used. The transparent resin may be mixed with fine particles for scattering light, whereby the light emission efficiency from the light exit surface can be further increased.
[0073] ここで、導光板 18の平行溝 18fの好ましい断面形状について詳細に説明する。な お、本発明において、平行溝の断面形状とは、平行溝を、その長さ方向に垂直な面 で切断したときに、平行溝を画成する導光板の壁面に相当する部分の部分線と、そ の部分線の両端を結ぶ直線とによって形成される形状を意味する。また、以下の説 明において、平行溝を、その長さ方向に垂直な面で切断したときの断面を、単に平 行溝の断面という。  Here, a preferable cross-sectional shape of the parallel grooves 18f of the light guide plate 18 will be described in detail. In the present invention, the cross-sectional shape of the parallel groove is a partial line corresponding to the wall surface of the light guide plate that defines the parallel groove when the parallel groove is cut along a plane perpendicular to its length direction. And a shape formed by a straight line connecting both ends of the partial line. In the following description, a cross section obtained by cutting a parallel groove along a plane perpendicular to its length direction is simply referred to as a cross section of a parallel groove.
[0074] 図 1A及び図 1Bにおける導光板 18の平行溝 18fは、その断面形状が三角形状に なるように形成されている。ここでは、平行溝 18fの断面形状を三角形状とした力 本 発明においては、平行溝 18fの断面形状は、当該平行溝 18fの最深部又は中心を 通って導光板 18fの、光射出面に垂直な中心線に対して対称であって、光射出面 1 8aに向力つて細くなるような形状であればよい。例えば、図 8及び前述した図 6A〜図 6Cに示すように、平行溝 18fを、その長さ方向に垂直な面で切断したときに、平行溝 18fを画成する導光板 18の壁面に相当する部分の線形状が、双曲線の一部又は楕 円の一部の形状になるように形成することができる。或いは、平行溝を画成する導光 板の壁面に相当する部分の線形状は懸垂線形状でも良 、。 [0074] The parallel grooves 18f of the light guide plate 18 in FIGS. 1A and 1B are formed so that the cross-sectional shape thereof is a triangular shape. In this example, the force of the parallel groove 18f is triangular. In the invention, the cross-sectional shape of the parallel groove 18f is symmetric with respect to the center line perpendicular to the light emission surface of the light guide plate 18f through the deepest part or center of the parallel groove 18f, and the light emission surface 18a. Any shape can be used as long as it becomes thinner. For example, as shown in FIG. 8 and FIGS. 6A to 6C described above, when the parallel groove 18f is cut along a plane perpendicular to its length direction, it corresponds to the wall surface of the light guide plate 18 that defines the parallel groove 18f. The line shape of the portion to be formed can be a shape of a part of a hyperbola or a part of an ellipse. Alternatively, the line shape corresponding to the wall surface of the light guide plate that defines the parallel grooves may be a suspended line shape.
[0075] 図 8に示したように、平行溝の断面において、平行溝 18fを画成する導光板 18の壁 面に相当する部分の線形状が双曲線の一部である場合には、平行溝 18fに収容さ れる導光体 72の断面も平行溝 18fの断面と略同一の形状に加工され得る。すなわち 、導光体 72の断面において、導光体 72の側面に相当する部分の線形状が双曲線 の一部となるように、導光体 72の側壁が形成される。  [0075] As shown in FIG. 8, in the cross section of the parallel groove, when the line shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f is a part of a hyperbola, the parallel groove The cross section of the light guide 72 accommodated in the 18f can also be processed into a shape substantially the same as the cross section of the parallel groove 18f. That is, in the cross section of the light guide 72, the side wall of the light guide 72 is formed so that the linear shape of the portion corresponding to the side surface of the light guide 72 becomes a part of a hyperbola.
[0076] また、本発明においては、平行溝の断面において、平行溝の最深部に相当する部 分が尖点となるような形状に平行溝を構成することもできる。すなわち、平行溝の断 面において、平行溝の最深部に相当する部分の線形状が、互いに交わる先鋭な 1つ の交点を有する、平行溝の中心を通って導光板の光射出面に垂直な中心線に対し て対称な 2つの曲線又は直線の一部力も形成することができる。本発明においては、 導光板の平行溝の断面形状が、上記いずれの形状であっても、導光板の光射出面 力も均一な光を出射させることができる。  [0076] Further, in the present invention, the parallel groove can be formed in such a shape that a portion corresponding to the deepest portion of the parallel groove becomes a cusp in the cross section of the parallel groove. That is, in the cross section of the parallel groove, the line shape of the portion corresponding to the deepest portion of the parallel groove has one sharp intersection that intersects each other, and is perpendicular to the light exit surface of the light guide plate through the center of the parallel groove. It is also possible to create partial forces that are two curves or straight lines that are symmetrical about the centerline. In the present invention, even if the cross-sectional shape of the parallel groove of the light guide plate is any of the above shapes, the light exit surface force of the light guide plate can be emitted uniformly.
[0077] 図 9には、平行溝の断面において、平行溝を画成する導光板の壁面に相当する部 分の線形状が、互いに交わる先鋭な 1つの交点を有し、平行溝 18fの中心を通って 導光板の光射出面に垂直な中心線に対して対称な 2つの曲線の一部力 なる場合 の一例を示した。図 9に示した導光板 50は、平行溝の中心を通って導光板 50の光 射出面 50aに垂直な中心線 Xに対して対称な 2つの曲線 54a及び 54bが円弧の場合 である。この場合は、図 9に示すように、平行溝 18fを形成する一方の側壁に対応す る円弧 54aの中心の位置と他方の側壁に対応する円弧 54bの中心の位置が異なる ように形成される。これにより円弧状の両側壁が交わる部分 56は、図 9に示すように 尖った形状となる。この場合、平行溝 18fに収容される導光体 57の側壁は、同図に 示したように、平行溝 18fの形状に応じた形状で加工され得る。 [0077] In FIG. 9, in the cross section of the parallel groove, the line shape of the portion corresponding to the wall surface of the light guide plate that defines the parallel groove has one sharp intersection that intersects each other, and the center of the parallel groove 18f An example is shown in which the partial force of two curves symmetric with respect to the center line perpendicular to the light exit surface of the light guide plate is shown. The light guide plate 50 shown in FIG. 9 is a case where two curves 54a and 54b symmetric with respect to the center line X passing through the center of the parallel groove and perpendicular to the light exit surface 50a of the light guide plate 50 are arcs. In this case, as shown in FIG. 9, the center position of the arc 54a corresponding to one side wall forming the parallel groove 18f is different from the center position of the arc 54b corresponding to the other side wall. . As a result, the portion 56 where the arc-shaped side walls meet has a sharp shape as shown in FIG. In this case, the side wall of the light guide 57 accommodated in the parallel groove 18f is shown in FIG. As shown, it can be processed in a shape corresponding to the shape of the parallel groove 18f.
[0078] また、図 10には、平行溝の断面において平行溝を画成する導光板の壁面に相当 する部分の線形状が、互いに交わる先鋭な 1つの交点を有する、平行溝の中心を通 つて導光板の光射出面に垂直な中心線に対して対称な 2つの曲線の一部力 なる 場合の更に別の例を示した。図 10に示した導光板 60は、平行溝 18fの中心を通つ て導光板の光射出面に垂直な中心線 Xに対して対称な 2つの曲線 64a及び 64bが 放物線の場合である。図 10においては、平行溝 18fの一方の側壁を形成する放物 線 64aの焦点と、他方の側壁 22bを形成する放物線 64bの焦点とが互いに異なるよう に、平行溝 18fの側壁が形成される。  [0078] Also, in FIG. 10, the linear shape of the portion corresponding to the wall surface of the light guide plate that defines the parallel grooves in the cross section of the parallel grooves has one sharp intersection where they intersect each other. Thus, another example is shown in the case of partial force of two curves symmetric with respect to the center line perpendicular to the light exit surface of the light guide plate. The light guide plate 60 shown in FIG. 10 is a case where two curves 64a and 64b which are symmetrical with respect to the center line X passing through the center of the parallel groove 18f and perpendicular to the light exit surface of the light guide plate are parabolas. In FIG. 10, the side wall of the parallel groove 18f is formed so that the focal point of the parabola 64a that forms one side wall of the parallel groove 18f is different from the focal point of the parabola 64b that forms the other side wall 22b. .
[0079] 図 10に示すように、平行溝の断面において当該平行溝 18fを画成する導光板 18 の壁面に相当する部分の線形状が、交点 66で交わる 2つの曲線 64a及び 64bから 形成される場合においては、平行溝 18fの一方の側壁に対応する曲線 64aの、交点 (尖点） 66における接線と、他方の側壁に対応する曲線 64bの、交点 64における接 線が互いになす角 Θは、 90度以下が好ましぐ 60度以下がより一層好ましい。  As shown in FIG. 10, the line shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f in the cross section of the parallel groove is formed from two curves 64a and 64b that intersect at an intersection 66. In this case, the angle Θ between the tangent line at the intersection (point) 66 of the curve 64a corresponding to one side wall of the parallel groove 18f and the tangent line at the intersection point 64 of the curve 64b corresponding to the other side wall is 90 degrees or less is preferable, and 60 degrees or less is even more preferable.
[0080] 以上、平行溝の断面において当該平行溝を画成する導光板の壁面に相当する部 分の線形状が、平行溝の中心に向かって凹形状の導光板の例を示したが、これらと は異なる本発明の導光板の別の態様を図 11及び図 12に示す。図 11は、平行溝の 断面における平行溝 18fを画成する導光板 18の壁面に相当する部分の線形状が、 平行溝 18fの中心に向力つて凸の 2つの曲線 73a及び 73bから形成される導光板 70 の例であり、図 12は、平行溝の断面における平行溝 18fを画成する導光板の壁面に 相当する部分の線形状が、平行溝 18fの中心に向力つて凸の曲線 82a及び 82bと凹 の曲線 84a及び 84bを組み合わせた曲線力も形成される導光板 80の例である。図 1 1及び図 12に示したような断面形状の平行溝を有する導光板 70及び 80も、輝線の 発生を抑制しつつ光射出面力 十分な照度の光を出射することができる。  [0080] The example of the light guide plate in which the line shape corresponding to the wall surface of the light guide plate that defines the parallel groove in the cross section of the parallel groove is concave toward the center of the parallel groove has been described above. Another embodiment of the light guide plate of the present invention different from these is shown in FIGS. In FIG. 11, the linear shape of the portion corresponding to the wall surface of the light guide plate 18 that defines the parallel groove 18f in the cross section of the parallel groove is formed from two curves 73a and 73b that are convex toward the center of the parallel groove 18f. FIG. 12 shows an example of the light guide plate 70, and the line shape of the portion corresponding to the wall surface of the light guide plate that defines the parallel groove 18f in the cross section of the parallel groove is a convex curve that is directed toward the center of the parallel groove 18f. This is an example of the light guide plate 80 in which a curved force combining 82a and 82b and concave curves 84a and 84b is also formed. The light guide plates 70 and 80 having the parallel grooves having the cross-sectional shapes as shown in FIGS. 11 and 12 can also emit light with sufficient light emission surface strength while suppressing generation of bright lines.
[0081] このように、平行溝の断面における最深部に相当する部分の線形状は、平行溝の 中心に向力つて凸若しくは凹の曲線状又は直線状にすることができ、それらの組み 合わせであってもよい。これらの曲線は、図示例の円弧に限定されず、平行溝の中 心に向力つて凸または凹の、楕円、放物線、または双曲線などの曲線の一部であれ ばよい。また、本発明においては、平行溝の断面において、平行溝の最深部に対応 する部分の形状が、後述するように先細化されていれば、平行溝を構成する曲線は 、平行溝の中心に向力つて凸または凹の、円、楕円、放物線、または双曲線などの曲 線の一部であれば良ぐ 10次の関数によって近似できる曲線であることが好ましい。 [0081] Thus, the linear shape of the portion corresponding to the deepest part in the cross section of the parallel groove can be made convex or concave curved or linear by directing toward the center of the parallel groove, and combinations thereof. It may be. These curves are not limited to the illustrated arc, but may be part of a curve such as an ellipse, parabola, or hyperbola that is convex or concave toward the center of the parallel grooves. That's fine. In the present invention, in the cross section of the parallel groove, if the shape of the portion corresponding to the deepest part of the parallel groove is tapered as described later, the curve constituting the parallel groove is at the center of the parallel groove. The curve is preferably a curve that can be approximated by a 10th-order function as long as it is part of a curved line such as a circle, ellipse, parabola, or hyperbola, convex or concave.
[0082] 図 10〜13においては、導光板の平行溝に収容される導光体を図示していないが 、同図に示すように導光板の平行溝を種々の形状に変更した場合は、その平行溝に 収容される導光体も平行溝の形状に応じた形状に加工することができる。 10 to 13, the light guide housed in the parallel groove of the light guide plate is not shown, but when the parallel groove of the light guide plate is changed to various shapes as shown in FIG. The light guide housed in the parallel groove can also be processed into a shape corresponding to the shape of the parallel groove.
[0083] 本発明の導光板においては、図 13に示すように、ある中心線 Xにおいて網点の密 度が高くその中心線 Xから両側（中心線に対して垂直方向）に向力うにしたがって次 第に網点の密度が低くなるような網点パターン 92を導光板 18の光射出面 18aに、例 えば、印刷により形成してもよい。このような網点パターン 92を、網点パターンの中心 線 Xが導光板 18の平行溝の中心線に対応する位置と一致するように、導光板 18の 光射出面 18aに形成することにより、導光板 18の光射出面 18aにおける輝線の発生 やムラを抑制することができる。また、網点パターン 92を導光板 18に印刷する代わり に、網点パターンが形成された薄いシートを光射出面上に積層しても良い。網点の 形状は、矩形、円形、楕円形などを任意の形状にすることができ、網点の密度は、輝 線の強さや広がりに応じて適宜選択することができる。また、このような網点パターン を印刷により形成する代わりに、網点パターンに対応する部分を砂擦り面として荒ら してもよい。このような砂擦り面は、導光板の平行溝の最深部や側壁に形成してもよ い。 In the light guide plate of the present invention, as shown in FIG. 13, the density of the halftone dot is high at a certain center line X, and as it is directed toward both sides (perpendicular to the center line) from the center line X. A halftone dot pattern 92 that gradually decreases the density of halftone dots may be formed on the light exit surface 18a of the light guide plate 18, for example, by printing. By forming such a halftone dot pattern 92 on the light exit surface 18a of the light guide plate 18 so that the center line X of the halftone dot pattern coincides with the position corresponding to the center line of the parallel groove of the light guide plate 18, Generation and unevenness of bright lines on the light exit surface 18a of the light guide plate 18 can be suppressed. Further, instead of printing the halftone dot pattern 92 on the light guide plate 18, a thin sheet on which the halftone dot pattern is formed may be laminated on the light emitting surface. The shape of the halftone dots can be any shape, such as a rectangle, a circle, or an ellipse, and the density of the halftone dots can be appropriately selected according to the intensity and spread of the bright lines. Further, instead of forming such a halftone dot pattern by printing, a portion corresponding to the halftone dot pattern may be roughened as a sanded surface. Such a rubbing surface may be formed at the deepest part or the side wall of the parallel groove of the light guide plate.
[0084] また、本発明者の知見によれば、導光板 18の平行溝 18fを構成する壁面部分の断 面形状が三角形状 (V字状)の導光板においては、光源 12の直上、すなわち、矩形 状光射出面 18aの中心部分の相対照度が低くなる。このような平行溝の断面形状が 三角形状の場合は、平行溝の頂点 (最深部)を所定の幅で平坦にするか、比較的曲 率半径の小さな曲面にすることによって、光射出面における照度を均一化することが 好ましい。本発明においては、導光板の平行溝の最深部の断面形状を上述したよう な形状になるように設計するだけで、導光板の光射出面における照度を最適に調整 して均一化することができる。 また、このように平行溝の最深部を上述の形状にした場合は、平行溝に収容される 棒状照明装置の導光体も、上述の形状と同一又は相似の形状になるように加工する ことが望ましい。 [0084] Further, according to the knowledge of the present inventor, in the light guide plate in which the cross-sectional shape of the wall surface portion constituting the parallel groove 18f of the light guide plate 18 is triangular (V-shaped), that is, directly above the light source 12, that is, The relative illuminance at the center of the rectangular light exit surface 18a is reduced. When the cross-sectional shape of such a parallel groove is a triangle, the apex (deepest part) of the parallel groove is flattened with a predetermined width or a curved surface having a relatively small radius of curvature, so that It is preferable to make the illuminance uniform. In the present invention, the illuminance on the light exit surface of the light guide plate can be optimally adjusted and made uniform simply by designing the cross-sectional shape of the deepest portion of the parallel groove of the light guide plate to be the shape described above. it can. In addition, when the deepest part of the parallel groove is formed in the above-described shape, the light guide body of the rod-shaped lighting device accommodated in the parallel groove is processed so as to have the same or similar shape as the above-described shape. Is desirable.
なお、本発明では、対称面 sにおいて背面が交差する部分における断面形状、す なわち平行溝の先端部分の断面形状が、面取りされた平坦状、もしくは、丸められた 円形状のみならず、楕円形状、放物線状、または双曲線状であっても良いのはもち ろんである。さらに、これに加え、その交差部分を砂擦り面とすることが好ましぐこれ により、光射出面における照度又は輝度のピーク値を低減することができる。  In the present invention, the cross-sectional shape at the portion of the symmetry plane s where the rear surfaces intersect, that is, the cross-sectional shape at the tip of the parallel groove is not only a chamfered flat shape or a rounded circular shape, but also an elliptical shape. Of course, it may be in the form of a shape, parabola, or hyperbola. Further, in addition to this, it is preferable that the intersecting portion is a sand rubbing surface, whereby the peak value of illuminance or luminance on the light exit surface can be reduced.
[0085] また、本発明の導光板においては、導光板の光射出面における照度分布において 、導光板 18の光射出面 18aの第 1部分の照度のピーク値が、導光板 18の光射出面 18aの第 2部分の照度の平均値の 3倍以下、より好ましくは、 2倍以下となるように、導 光板 18の平行溝 18fの先端形状の先細化を行う。ここで、導光板 18の光射出面 18a の第 1部分の照度のピーク値力 導光板 18の光射出面 18aの第 2部分の照度の平 均値の 3倍以下となるようにするのは、導光板 18の光射出面 18aから射出された照 明光の照度分布が、従来より均一化されるからであり、その結果、導光板 18の光射 出面 18aから射出された照明光の拡散 (ミキシングなど)をそれほど十分に行う必要 がなぐ拡散効率のあまり高くない低コストの拡散シート 14の使用が可能となり、また 使用枚数を減らすことができ、また、高価なプリズムシート 16、 17および 19自体の使 用を止めることができ、あるいは、拡散効率のあまり高くない低コストのプリズムシート 16、 17および 19の使用が可能となったり、使用枚数を減らすことができるからである  In the light guide plate of the present invention, in the illuminance distribution on the light exit surface of the light guide plate, the peak value of the illuminance at the first portion of the light exit surface 18a of the light guide plate 18 is the light exit surface of the light guide plate 18. The tip of the parallel groove 18f of the light guide plate 18 is tapered so that the average value of the illuminance of the second part 18a is 3 times or less, more preferably 2 times or less. Here, the peak value force of the illuminance of the first portion of the light exit surface 18a of the light guide plate 18 is set to be not more than three times the average value of the illuminance of the second portion of the light exit surface 18a of the light guide plate 18. This is because the illuminance distribution of the illumination light emitted from the light exit surface 18a of the light guide plate 18 is made more uniform than before, and as a result, the diffusion of the illumination light emitted from the light exit surface 18a of the light guide plate 18 ( It is possible to use a low-cost diffusion sheet 14 with a low diffusion efficiency that does not need to be mixed sufficiently, and the number of sheets used can be reduced, and the expensive prism sheets 16, 17 and 19 themselves This is because the use of low-cost prism sheets 16, 17 and 19 with low diffusion efficiency can be used, and the number of sheets used can be reduced.
[0086] 以上、本発明の導光板の形状について説明したが、上述した形状の導光板は、図 14に示すように、複数個の導光板 18をその端面同士が互いに密接するように接続さ れて、大きな光射出面を有する導光部材として構成され得る。このように複数の導光 板 18を、それらすベての光射出面 18aが同一平面を構成するように並列して配置し た場合は、ある導光板 18の平行溝に設けられた導光体 32から出射した光の一部が 、その導光板 18の内部の傾斜面で反射された後、その導光板 18の端面に到達され て、その端面と接続する隣の導光板の端面力 当該隣の導光板の内部に入射される 。このように複数個の導光板を、それらの光射出面が同一平面を構成するように並列 して配置すれば、隣に位置する導光板に配置された導光体力 の光をも利用するこ とができるので、光の出射効率を高めることができる。そして、更には、導光体を連結 したときに、隣接する導光板の接続部における導光体の背面の光射出面に対する傾 きが零 (0)になるように構成することにより、それら連結された導光板の光射出面の端 面に対応する部分、すなわち連結部分において、輝線が発生することを一層抑制す ることがでさる。 [0086] The shape of the light guide plate of the present invention has been described above. The light guide plate having the above-described shape is connected to a plurality of light guide plates 18 such that end surfaces thereof are in close contact with each other, as shown in FIG. Thus, it can be configured as a light guide member having a large light exit surface. In this way, when a plurality of light guide plates 18 are arranged in parallel so that all the light exit surfaces 18a constitute the same plane, the light guides provided in the parallel grooves of a certain light guide plate 18 are arranged. A part of the light emitted from the body 32 is reflected by the inclined surface inside the light guide plate 18 and then reaches the end surface of the light guide plate 18 and the end surface force of the adjacent light guide plate connected to the end surface Incident inside the adjacent light guide plate . In this way, if a plurality of light guide plates are arranged in parallel so that their light exit surfaces constitute the same plane, the light of the light guide force arranged on the adjacent light guide plate can also be used. Therefore, the light emission efficiency can be increased. In addition, when the light guides are connected, the inclination of the back surface of the light guide with respect to the light exit surface at the connection portion of the adjacent light guide plates becomes zero (0). It is possible to further suppress the occurrence of bright lines in the portion corresponding to the end surface of the light exit surface of the light guide plate, that is, the connecting portion.
導光板をこのように複数並べて配置することにより、光射出面から出射する光束の 光量分布が均一で、輝線の発生が抑制された大サイズの光照射面を有する面状照 明装置とすることができる。そして、このような大サイズの光照射面を有する面状照明 装置は、大サイズの表示画面を有する液晶表示装置に適用することができ、特に、 壁掛けテレビなどの壁掛けタイプの液晶表示装置用に最適である。  By arranging a plurality of light guide plates side by side in this manner, a planar illumination device having a large-sized light irradiation surface in which the light amount distribution of the light beam emitted from the light exit surface is uniform and the generation of bright lines is suppressed is obtained. Can do. Such a planar illumination device having a large-size light irradiation surface can be applied to a liquid crystal display device having a large-size display screen, particularly for a wall-mounted liquid crystal display device such as a wall-mounted television. Is optimal.
[0087] 以上の説明においては、導光板の背面を平坦な面で形成したが、これには限定さ れず、例えば、 10次関数で表わされる形状にしても良い。この場合は、 10次関数の 各係数は、導光板の平行溝に収容される導光体力 出射する光が、その 1つの導光 板からすべて出射するように決定してもよ 、し、複数個の導光板を連結したときに、 複数の導光板からすべて出射するように決定しても良 、。  In the above description, the back surface of the light guide plate is formed as a flat surface. However, the present invention is not limited to this. For example, a shape represented by a tenth order function may be used. In this case, each coefficient of the tenth-order function may be determined so that light emitted from the light guide body accommodated in the parallel groove of the light guide plate is emitted from all of the one light guide plate. It may be determined that when light guide plates are connected, all light is emitted from a plurality of light guide plates.
[0088] 以上、本発明の面状照明装置を構成する導光板について説明した。次に、図 1A 及び図 1Bに示した面状照明装置 2の拡散シート 14について説明する。拡散シート 1 4は、導光板 18の光射出面 18aから出射する光を拡散して均一化するために用いら れる。拡散シート 14は、例えば、 PET (ポリエチレンテレフタレート）、 PP (ポリプロピレ ン）、 PC (ポリカーボネート）、 PMMA (ポリメチノレメタタリレート）、ペンジノレメタクリレー トゃ MS榭脂、その他のアクリル系榭脂、あるいは COP (シクロォレフィンポリマー）の ような光学的に透明な榭脂からなる平板状部材に光拡散性を付与して形成される。 その方法は特に限定されないが、例えば、上記平板状部材の表面に微細凹凸加工 や研磨による表面粗化 (以降これらを施した面を「砂擦り面」という。）を施して拡散性 を付与したり、表面に光を散乱させるシリカ、酸化チタン、酸化亜鉛等の顔料もしくは 榭脂ゃガラス、ジルコユア等のビーズ類をバインダとともに塗工したり、上記の榭脂中 に光を散乱させる前述の顔料、ビーズ類を混練することで形成される。本発明におい て、拡散シート 14としては、マットタイプやコーティングタイプの拡散シートを用いるこ とがでさる。 [0088] The light guide plate constituting the planar lighting device of the present invention has been described above. Next, the diffusion sheet 14 of the planar lighting device 2 shown in FIGS. 1A and 1B will be described. The diffusion sheet 14 is used to diffuse and make uniform the light emitted from the light exit surface 18a of the light guide plate 18. Diffusion sheet 14 is made of, for example, PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), PMMA (polymethylol methacrylate), penzino methacrylate methacrylate, MS resin, other acrylic resins, Alternatively, it is formed by imparting light diffusibility to a flat plate member made of an optically transparent resin such as COP (cycloolefin polymer). The method is not particularly limited. For example, the surface of the flat plate member is subjected to surface roughening by fine unevenness processing or polishing (hereinafter, the surface on which these are applied is referred to as “sand-rubbed surface”) to impart diffusibility. In addition, pigments such as silica, titanium oxide, zinc oxide, etc. that scatter light on the surface, or beads such as resin glass, zirconium oxide, etc. can be applied together with a binder, It is formed by kneading the aforementioned pigment and beads that scatter light. In the present invention, as the diffusion sheet 14, a mat type or coating type diffusion sheet can be used.
本発明において、拡散シート 14としては、上記の素材を用い、かつ、光拡散性を付 与した厚み 500 μ m以下のフィルム状部材を用いることも好まし 、。  In the present invention, as the diffusion sheet 14, it is also preferable to use a film-like member having a thickness of 500 μm or less that uses the above-mentioned material and imparts light diffusibility.
[0089] また、拡散シート 14は、導光板 18の光射出面 18aから所定の距離だけ離して配置 されることが好ましぐその距離は導光板 18の光射出面 18aからの光量分布に応じて 適宜変更し得る。このように拡散シート 14を導光板 18の光射出面 18aから所定の間 隔だけ離すことにより、導光板 18の光射出面 18aから射出する光が、光射出面 18aと 拡散シート 14の間で更にミキシング (混合)される。これにより、拡散シート 14を透過 して液晶表示パネル 4を照明する光の照度を、より一層均一化することができる。拡 散シート 14を導光板 18の光射出面 18aから所定の間隔だけ離す方法としては、例 えば、拡散シート 14と導光板 18との間にスぺーサを設ける方法を用いることができる [0089] Further, it is preferable that the diffusion sheet 14 is disposed at a predetermined distance from the light exit surface 18a of the light guide plate 18. The distance depends on the light amount distribution from the light exit surface 18a of the light guide plate 18. Can be changed as appropriate. Thus, by separating the diffusion sheet 14 from the light exit surface 18a of the light guide plate 18 by a predetermined interval, light emitted from the light exit surface 18a of the light guide plate 18 is transmitted between the light exit surface 18a and the diffusion sheet 14. It is further mixed (mixed). Thereby, the illuminance of the light that passes through the diffusion sheet 14 and illuminates the liquid crystal display panel 4 can be made more uniform. As a method of separating the diffusion sheet 14 from the light exit surface 18a of the light guide plate 18 by a predetermined distance, for example, a method of providing a spacer between the diffusion sheet 14 and the light guide plate 18 can be used.
[0090] 特に、面状照明装置 2の厚みを少し厚くしてもよい場合には、導光板 18の平行溝 1 8fの断面形状によって、平行溝 18fに相当する導光板 18の光射出面 18aにおける 照度のピーク値を十分に低減する必要はなぐ部分的に低減するとともに拡散シート 14と導光板 18の光射出面 18aとの間に間隙を設けて、拡散シート 14から射出される 照明光を照度分布を均一にしても良い。また、導光板 18の平行溝 18fの断面形状の 改良（平行溝の先端部分の先細化）に限界があり、平行溝 18fに相当する導光板 18 の光射出面 18aにおける照度のピーク値を完全に低減できない場合や十分に低減 できない場合にも、拡散シート 14と導光板 18の光射出面 18aとの間に間隙を設けて 、拡散シート 14から射出される照明光の照度分布を均一にしても良い。 [0090] In particular, when the thickness of the planar illumination device 2 may be slightly increased, the light exit surface 18a of the light guide plate 18 corresponding to the parallel groove 18f is obtained depending on the cross-sectional shape of the parallel grooves 18f of the light guide plate 18. It is not necessary to sufficiently reduce the peak value of illuminance at the same time, and a gap is provided between the diffusion sheet 14 and the light exit surface 18a of the light guide plate 18 to reduce the illumination light emitted from the diffusion sheet 14. The illuminance distribution may be uniform. In addition, there is a limit to the improvement of the cross-sectional shape of the parallel groove 18f of the light guide plate 18 (tapering of the tip of the parallel groove), and the peak value of illuminance on the light exit surface 18a of the light guide plate 18 corresponding to the parallel groove 18f is completely Even when it cannot be reduced to a sufficient level or when it cannot be sufficiently reduced, a gap is provided between the diffusion sheet 14 and the light exit surface 18a of the light guide plate 18 so that the illuminance distribution of the illumination light emitted from the diffusion sheet 14 is uniform. Also good.
[0091] 次に、図 1A及び図 1Bに示す面状照明装置のプリズムシートについて説明する。プ リズムシート 16及び 17は、複数のプリズムを平行に配列させることにより形成された 透明なシートであり、導光板 18の光射出面 18aから出射する光の集光性を高めて輝 度を改善することができる。プリズムシート 16及び 17の一方は、そのプリズム列の延 在する方向が導光板 18の平行溝 18fと平行になるように配置され、他方は垂直にな るように配置されている。すなわち、プリズムシート 16及び 17は、プリズム列の延在す る方向が互いに垂直になるように配置されている。また、プリズムシート 16は、プリズ ムの頂角が導光板 18の光射出面 18aと対向するように配置される。ここで、プリズム シート 16及び 17の配置順序は、導光板の直上に、導光板の平行溝と平行な方向に 延在するプリズムを有するプリズムシート 16を配置し、そのプリズムシート 16の上に、 導光板 18の平行溝 18fと垂直な方向に延在するプリズムを有するプリズムシートを配 置しても良ぐまた、その逆でも良い。 Next, the prism sheet of the planar lighting device shown in FIGS. 1A and 1B will be described. The prism sheets 16 and 17 are transparent sheets formed by arranging a plurality of prisms in parallel, and improve the light condensing property of the light emitted from the light exit surface 18a of the light guide plate 18 to improve the brightness. can do. One of the prism sheets 16 and 17 is arranged so that the extending direction of the prism row is parallel to the parallel groove 18f of the light guide plate 18, and the other is vertical. It is arranged so that. That is, the prism sheets 16 and 17 are arranged such that the extending directions of the prism rows are perpendicular to each other. The prism sheet 16 is arranged so that the apex angle of the prism faces the light exit surface 18 a of the light guide plate 18. Here, the arrangement order of the prism sheets 16 and 17 is such that a prism sheet 16 having a prism extending in a direction parallel to the parallel groove of the light guide plate is arranged immediately above the light guide plate, and on the prism sheet 16, A prism sheet having prisms extending in a direction perpendicular to the parallel grooves 18f of the light guide plate 18 may be disposed, or vice versa.
[0092] また、図示例では、プリズムシートを用いたが、プリズムシートの代わりに、プリズム に類する光学素子が規則的に配置されたシートを用いても良い。また、レンズ効果を 有する素子、例えば、レンチキュラーレンズ、凹レンズ、凸レンズ、ピラミッド型などの 光学素子を規則的に備えるシートをプリズムシートの代わりに用いることもできる。  In the illustrated example, a prism sheet is used. However, instead of the prism sheet, a sheet in which optical elements similar to prisms are regularly arranged may be used. In addition, a sheet that regularly includes optical elements such as a lens effect, such as a lenticular lens, a concave lens, a convex lens, and a pyramid type, can be used instead of the prism sheet.
[0093] 本発明においては、更に、図 15A及び図 15Bに示すように、反射シート 22と傾斜 背面 18dとの間にもプリズムシート 19を設けることが好ましい。図 15Aは、反射シート 22と導光板 18の傾斜背面 18dとの間にプリズムシート 19が配置されている様子を示 す概略断面図であり、図 15Bは、反射シート 22と導光板 18の傾斜背面 18dとの間に 配置されているプリズムシート 19を導光板側から見たときの概略平面図及びそのプリ ズムシート 19の概略横断面図である。反射シート 22と導光板 18の傾斜背面 18dとの 間に設けられるプリズムシート 19は、プリズム 19aの延在する方向が導光板 18の平 行溝 18fと垂直になるように配置されるとともに、プリズム 19aの頂角が導光板 18の傾 斜背面 18dと対向するように配置することが好ま 、。  In the present invention, as shown in FIGS. 15A and 15B, it is preferable that a prism sheet 19 is also provided between the reflection sheet 22 and the inclined back surface 18d. 15A is a schematic cross-sectional view showing a state in which the prism sheet 19 is disposed between the reflection sheet 22 and the inclined back surface 18d of the light guide plate 18. FIG. 15B is an inclination of the reflection sheet 22 and the light guide plate 18. FIG. 4 is a schematic plan view of the prism sheet 19 disposed between the back surface 18d and the light guide plate side, and a schematic cross-sectional view of the prism sheet 19. FIG. The prism sheet 19 provided between the reflection sheet 22 and the inclined rear surface 18d of the light guide plate 18 is arranged so that the extending direction of the prism 19a is perpendicular to the parallel groove 18f of the light guide plate 18, and the prism 19 It is preferable to arrange so that the apex angle of 19a faces the inclined rear surface 18d of the light guide plate 18.
[0094] ここではプリズムシートを用いた力 プリズムシートと同様の効果を有する光学素子 を用いても良ぐレンズ効果を有する光学素子、例えば、レンチキュラーレンズ、凹レ ンズ、凸レンズ、ピラミッド型などの光学素子が規則的に配置されたシートを設けても 良い。  [0094] Here, the force using a prism sheet. An optical element having a lens effect that may be an optical element having an effect similar to that of a prism sheet, such as an optical element such as a lenticular lens, a concave lens, a convex lens, or a pyramid type. A sheet in which elements are regularly arranged may be provided.
なお、図示例においては、プリズムシート 16および 17、さらに好ましくはプリズムシ ート 19を用いているが、導光板 18の平行溝 18fによる光射出面 18aにおける照度が より均一化されている場合には、プリズムシート 19はもちろん不要であるし、プリズム シート 16および 17のどちらか一方、または両方を用いなくても良い。高価なプリズム シートの使用枚数を減らし、あるいは、プリズムシートの使用をやめることにより、装置 コストを低減させることができる。 In the illustrated example, the prism sheets 16 and 17, more preferably the prism sheet 19, are used. However, when the illuminance on the light exit surface 18a by the parallel grooves 18f of the light guide plate 18 is made more uniform. Of course, the prism sheet 19 is unnecessary, and either one or both of the prism sheets 16 and 17 may not be used. Expensive prism By reducing the number of sheets used or stopping the use of prism sheets, the cost of the apparatus can be reduced.
[0095] つぎに、図 1A及び図 1Bに示す面状照明装置 2の反射シートについて説明する。  Next, the reflection sheet of the planar illumination device 2 shown in FIGS. 1A and 1B will be described.
図 1A及び図 1Bにおいて、反射シート 22は、導光板 18の背面（図中、下面)から漏 洩する光を反射して、再び導光板 18に入射させるために用いられ、光の利用効率を 向上させることができる。反射シート 22は、導光板 18の下面 (傾斜面）を覆うように形 成される。リフレクタ 20は、導光板 18の平行溝 18fを塞ぐように導光体 32の背後に設 けられる。リフレクタ 20は、導光体 32の下面から光を反射して、導光板 18の平行溝 1 8fの側壁面力も光を入射させることができる。  In FIG. 1A and FIG. 1B, the reflection sheet 22 is used to reflect light leaking from the back surface (the lower surface in the figure) of the light guide plate 18 and to make it incident on the light guide plate 18 again. Can be improved. The reflection sheet 22 is formed so as to cover the lower surface (inclined surface) of the light guide plate 18. The reflector 20 is provided behind the light guide 32 so as to close the parallel grooves 18 f of the light guide plate 18. The reflector 20 reflects light from the lower surface of the light guide 32, and the side wall surface force of the parallel grooves 18 f of the light guide plate 18 can also make the light incident.
[0096] 反射シート 22は、導光板 18の背面（図中、下面)から漏洩する光を反射することが できるのであれば、どのような材料で形成されてもよぐ例えば、 PETや PP (ポリプロ ピレン)等にフィラーを混練後延伸することによりボイドを形成して反射率を高めた榭 脂シート、透明もしくは上記のような白色の榭脂シート表面にアルミ蒸着などで鏡面 を形成したシート、アルミ等の金属箔もしくは金属箔を担持した榭脂シート、あるいは 表面に十分な反射性を有する金属薄板により形成することができる。また、リフレクタ 20は、例えば、上記反射シートと同じ素材、すなわち、表面に十分な反射性を付与 した榭脂素材、金属箔もしくは金属板により形成することができる。  [0096] The reflection sheet 22 may be formed of any material as long as it can reflect light leaking from the back surface (the lower surface in the figure) of the light guide plate 18. For example, PET or PP ( A resin sheet in which voids are formed by kneading and stretching the filler in (polypropylene) and the like to increase the reflectance, a sheet having a mirror surface formed by aluminum vapor deposition on the surface of a transparent or white resin sheet as described above, It can be formed of a metal foil such as aluminum or a resin sheet carrying the metal foil, or a metal thin plate having sufficient reflectivity on the surface. Further, the reflector 20 can be formed of, for example, the same material as that of the reflection sheet, that is, a resin material, a metal foil, or a metal plate that gives the surface sufficient reflectivity.
[0097] ここで、図 14においては、独立した複数個の導光板を連結して大型の導光ユニット を形成した形態について説明したが、出射光の均一性を高める上では 2個以上の導 光板を一体に成形することが好ましい。特に、製造効率の観点からは、必要な画面 サイズに相当する導光板を形成するのに必要な数の本発明の導光ユニットを一体で 成形することが好ましい。このような構成にすることにより、一枚の導光板で、光射出 面から出射する光束の光量分布が均一で、輝線の発生が抑制された大サイズの光 照射面を有する薄型の面状照明装置を実現することができる。また、このような一体 の導光板は、例えば、押出成形法を用いて容易に製造することができる。  Here, in FIG. 14, a mode has been described in which a plurality of independent light guide plates are connected to form a large light guide unit. However, in order to improve the uniformity of emitted light, two or more guides are used. It is preferable to integrally mold the light plate. In particular, from the viewpoint of manufacturing efficiency, it is preferable to integrally form the number of light guide units of the present invention necessary for forming a light guide plate corresponding to a required screen size. With such a configuration, a thin planar illumination having a large-size light irradiation surface in which the distribution of the amount of light emitted from the light exit surface is uniform and the generation of bright lines is suppressed with a single light guide plate. An apparatus can be realized. Moreover, such an integrated light guide plate can be easily manufactured using, for example, an extrusion molding method.
[0098] また、図 14に示したように、導光板を複数連結して導光ユニットを構成した場合は、 一方の導光板の端面部から他方の導光板に向力つて光が透過する際に、その端面 部において光の散乱などが生じる恐れがある。し力しながら、複数の導光板が一体と なって成形された導光ユニットにおいては、そのような端面部での光の散乱は発生し ないので、光源力もの光の利用効率を更に高めることができる。 [0098] As shown in FIG. 14, when a light guide unit is configured by connecting a plurality of light guide plates, light is transmitted from the end surface portion of one light guide plate to the other light guide plate. In addition, light scattering may occur at the end face. Multiple light guide plates are integrated with each other In the light guide unit thus formed, such light scattering does not occur at the end face portion, so that it is possible to further increase the light use efficiency even with light source power.
[0099] また、導光板の側面の面積などを考慮して、図 16Aに示すように、導光板 18の側 面に反射板 24を配置してもよい。また、上述したように、導光板 18を複数配置する場 合には、図 16Bに示すように、最も外側に配置される導光板 18の側面に反射板 24 を配置すればょ 、。このような反射板 24を側面に配置することで導光板 24の側面か らの光の漏出を防止することができ、光利用効率を一層高めることができる。反射板 2 4は、前述した反射シートやリフレクタと同様な材料を用いて形成することができる。 また、上記実施形態では、本発明の棒状照明装置及び面状照明装置を、液晶表 示装置を照明するために用いたが、天井照明や壁面照明などの照明装置としても利 用することができる。  [0099] In consideration of the area of the side surface of the light guide plate and the like, a reflector 24 may be disposed on the side surface of the light guide plate 18 as shown in FIG. 16A. Further, as described above, when a plurality of light guide plates 18 are arranged, as shown in FIG. 16B, the reflector 24 should be arranged on the side surface of the light guide plate 18 arranged on the outermost side. By disposing such a reflection plate 24 on the side surface, light leakage from the side surface of the light guide plate 24 can be prevented, and the light utilization efficiency can be further enhanced. The reflection plate 24 can be formed using the same material as the above-described reflection sheet and reflector. Further, in the above embodiment, the rod-like illumination device and the planar illumination device of the present invention are used for illuminating the liquid crystal display device, but can also be used as illumination devices such as ceiling illumination and wall illumination. .
[0100] ここで、本発明に従う面状照明装置の上記例とは異なる構成例について図面を参 照しながら説明する。  Here, a configuration example different from the above example of the planar illumination device according to the present invention will be described with reference to the drawings.
まず、光ファイバを用いて導光板に光を入射させるタイプの面状照明装置について 説明する。図 17Aに、そのような面状照明装置を構成する導光板 18の模式的断面 図を示し、図 17Bにその導光板 18を背面側力も見た模式的下面図を示した。図 17 Aに示すように、導光板 18の平行溝 18fを構成するそれぞれの壁面 (傾斜面） 18gに 接して、透明材料で形成された導光体 86が設けられている。導光体 86は、薄い板状 の透明体であり、表面 86aが曲面状に形成されている。また、導光体 86は、図 17A に示すように、中央に向かうに従って一定の幅のまま厚さだけが次第に薄くなるように 形成されている。導光体 86の端面 86bには、それぞれ、図 17Bに示すように 6つの 光ファイバ 88が配置されている。また、光ファイバ 88は、図示しない LEDと接続され ている。  First, a planar illumination device of a type in which light is incident on a light guide plate using an optical fiber will be described. FIG. 17A shows a schematic cross-sectional view of the light guide plate 18 constituting such a planar illumination device, and FIG. 17B shows a schematic bottom view of the light guide plate 18 in which the back side force is also seen. As shown in FIG. 17A, light guides 86 made of a transparent material are provided in contact with the respective wall surfaces (inclined surfaces) 18g constituting the parallel grooves 18f of the light guide plate 18. The light guide 86 is a thin plate-like transparent body, and the surface 86a is formed in a curved surface shape. In addition, as shown in FIG. 17A, the light guide 86 is formed so that only the thickness gradually decreases with a constant width toward the center. As shown in FIG. 17B, six optical fibers 88 are arranged on the end face 86b of the light guide 86, respectively. The optical fiber 88 is connected to an LED (not shown).
[0101] 導光体 86は、長さ方向に厚さが次第に薄くなつているため、導光体 86の曲面 86a は、導光体 86の端面 86bから入射する光の光軸に対して傾斜している。したがって、 導光体 86の端面 86bから内部に直進して入射した光は、導光体 86の内部の曲面に おいて反射し、導光板 18の平行溝 18fの傾斜面 18g側に向かう。そして、導光板 18 の内部に入射し、傾斜背面 18dで反射した後、光射出面 18aから出射する。 このような構造を有する面状照明装置は、入射した光線を順次立ち上げる線状光 源となる導光体と該導光体力 出射した光線を平面に広げる導光体の組み合わせか らなるため出射光をより均一にすることが可能となる。 [0101] Since the light guide 86 is gradually thinner in the length direction, the curved surface 86a of the light guide 86 is inclined with respect to the optical axis of light incident from the end face 86b of the light guide 86. is doing. Therefore, the light that has entered straight from the end face 86 b of the light guide 86 is reflected on the curved surface inside the light guide 86 and travels toward the inclined face 18 g of the parallel groove 18 f of the light guide plate 18. The light then enters the light guide plate 18 and is reflected by the inclined back surface 18d, and then exits from the light exit surface 18a. The planar illumination device having such a structure is composed of a combination of a light guide that becomes a linear light source that sequentially raises incident light rays and a light guide that spreads the light rays emitted from the light guide force on a plane. Irradiation can be made more uniform.
[0102] つぎに、本発明に従う面状照明装置として、図 1A及び図 1Bに示した導光板 (第 1 導光体） 18の平行溝 18fに、棒状の導光体 (第 2導光体)を一体になるように組み込 んだ面状照明装置について説明する。図 18Aに、導光体 94が平行溝 18fに組み込 まれた導光板 18の模式的断面図を示し、図 18Bに、その導光板 18を背面側から見 た模式的下面図を示した。また、図 19には、このような導光体 94の模式的斜視図を 示した。図 18A及び図 18Bに示した面状照明装置においては、導光体 94の両方の 端面 94aから光ファイバ 88を用いて光を入射させる。  [0102] Next, as a planar illumination device according to the present invention, a rod-shaped light guide (second light guide) is formed in the parallel grooves 18f of the light guide plate (first light guide) 18 shown in FIGS. 1A and 1B. ) Will be described. FIG. 18A shows a schematic cross-sectional view of the light guide plate 18 in which the light guide 94 is incorporated in the parallel groove 18f, and FIG. 18B shows a schematic bottom view of the light guide plate 18 viewed from the back side. FIG. 19 shows a schematic perspective view of such a light guide 94. In the planar illumination device shown in FIGS. 18A and 18B, light is incident from both end faces 94a of the light guide 94 using the optical fiber 88.
[0103] 導光体 94は、図 19に示すように、 3つの側面のうちの一つの側面（下面） 94bに、 長さ方向に垂直な断面における形状が V字状の溝 (以下 V字溝と 、う） 94cを有して いる。導光体 94の下面 94bの V字溝 94cは、その深さが、中央に向力 に従って次 第に深くなり、また、長さ方向に垂直な方向の幅が、中央に向かうに従って次第に広 くなる形状を有している。このような導光体 94は、長さ方向において、一方の端面 95 aから他方の端面 95cに向かうに従って溝幅が広くなり、溝深さが深くなるような V字 溝 95cが形成されている 2つの透明体 95A及び 95Bの溝幅の広い側の端面 95d同 士を密着させて接続することによって構成することができる。また、導光体 94の V字 溝 94cを構成する壁面 94eにはプリズムが形成されている。  [0103] As shown in FIG. 19, the light guide 94 has a V-shaped groove (hereinafter referred to as a V-shaped groove) in one of the three side surfaces (bottom surface) 94b. It has a groove 94c. The depth of the V-shaped groove 94c of the lower surface 94b of the light guide 94 becomes deeper according to the directional force at the center, and the width in the direction perpendicular to the lengthwise direction becomes gradually wider toward the center. It has the shape which becomes. In such a light guide 94, a V-shaped groove 95c is formed such that the groove width increases in the length direction from one end face 95a to the other end face 95c, and the groove depth increases. The two transparent bodies 95A and 95B can be configured by closely connecting the end surfaces 95d on the wide groove side. Further, a prism is formed on the wall surface 94e constituting the V-shaped groove 94c of the light guide 94.
[0104] 図 18Bに示すように、導光体 94の両端面 94aには、それぞれ、 6つの光ファイバ 88 が配置されている。それぞれの光ファイバ 88は、図示しない LEDと接続されており、 その LEDで発せられた光を導光体 94の端面 94aに照射することができる。導光体 9 4の V字溝 94cを構成する壁面は、入射光の光軸に対して傾斜しているので、導光体 94の端面 94aから導光体 94の内部に入射した光ファイノからの光は、導光体 94の V字溝 94cの壁面に到達し、その壁面に形成されたプリズムよって反射する。導光体 94のプリズムで反射した光は、導光板 18の平行溝 18fから入射し、導光板 18の傾斜 背面 18dで反射した後、導光板 18の光射出面 18aから出射する。  As shown in FIG. 18B, six optical fibers 88 are arranged on both end faces 94a of the light guide 94, respectively. Each optical fiber 88 is connected to an LED (not shown), and the light emitted from the LED can irradiate the end face 94a of the light guide 94. Since the wall surface forming the V-shaped groove 94c of the light guide 94 is inclined with respect to the optical axis of the incident light, the light fino that has entered the light guide 94 from the end face 94a of the light guide 94 is used. The light reaches the wall surface of the V-shaped groove 94c of the light guide 94 and is reflected by the prism formed on the wall surface. The light reflected by the prism of the light guide 94 is incident from the parallel groove 18f of the light guide plate 18, reflected by the inclined rear surface 18d of the light guide plate 18, and then emitted from the light exit surface 18a of the light guide plate 18.
[0105] つぎに、本発明の面状照明装置に用いられる導光板の別の構成例として、長さ方 向に垂直な断面が楕円の一部を取り除いた形状の平行溝が形成され、その平行溝 に、導光体を収容した導光板について説明する。図 20A及び図 20Bに、そのような 導光板の構成例を示した。図 20Aは、平行溝に第 2導光体が収容された導光板の模 式的断面図であり、図 20Bは、その導光板を背面側力も見た模式的下面図である。 また、図 21には、そのような導光板 90に収容される導光体 96の模式的斜視図を示し た。図 19Aに示すように、面状照明装置に用いられる導光板 90は、長さ方向に垂直 な断面が楕円の一部を取り除いた形状の平行溝 90fが形成されている。導光体 96は 、導光板 90の平行溝 90fに一体的に収容されるように、その外形が平行溝 90fと略 同様の形状で形成されている。また、導光体 96の下面 96bには、長さ方向に垂直な 断面形状が、楕円の一部を取り除いたような U字状の溝 96cが形成されている。この U字溝 96cは、長さ方向に次第に溝深さが深くなるとともに、溝幅が広くなるような溝 が形成された 2つの透明体 97A及び 97Bの溝幅の広い側の端面同士を密着させて 接続されている。導光体 96は、その曲面が、導光板 90の平行溝 90fの壁面と密着す るように導光板 90の平行溝 90f内に配置されて 、る。 Next, as another configuration example of the light guide plate used in the planar lighting device of the present invention, the length direction A description will be given of a light guide plate in which a parallel groove having a shape in which a section perpendicular to the direction is removed from an ellipse is formed and a light guide is accommodated in the parallel groove. FIG. 20A and FIG. 20B show a configuration example of such a light guide plate. FIG. 20A is a schematic cross-sectional view of the light guide plate in which the second light guide is accommodated in the parallel grooves, and FIG. 20B is a schematic bottom view of the light guide plate in which the back side force is also viewed. FIG. 21 shows a schematic perspective view of the light guide 96 accommodated in such a light guide plate 90. As shown in FIG. 19A, the light guide plate 90 used in the planar illumination device has a parallel groove 90f having a shape in which a section perpendicular to the length direction is removed from an ellipse. The light guide 96 has an outer shape substantially the same as that of the parallel groove 90f so that the light guide 96 is integrally accommodated in the parallel groove 90f of the light guide plate 90. In addition, the lower surface 96b of the light guide 96 is formed with a U-shaped groove 96c having a cross-sectional shape perpendicular to the length direction in which a part of an ellipse is removed. The U-shaped groove 96c has a groove depth that gradually increases in the lengthwise direction, and the end faces of the two transparent bodies 97A and 97B on which the groove width is widened are in close contact with each other. Connected. The light guide 96 is disposed in the parallel groove 90f of the light guide plate 90 so that the curved surface thereof is in close contact with the wall surface of the parallel groove 90f of the light guide plate 90.
[0106] 導光体 96の両方の端面 96aには、 6本の光ファイバ 88がそれぞれ配置されている 。光ファイバ 88は、図示しない LEDから発せられた光を導光体 96の端面 96aから導 光体 96の内部に入射させることができる。このような構造を有する導光体 96は、 U字 溝 96cを構成する壁面が入射光の光軸に対して傾斜して ヽるので、入射光は U字溝 96cの壁面で反射した後、導光板 90の平行溝 90fを介して導光板 90の内部に入射 する。そして、導光板 90の傾斜背面において反射した後、光射出面から出射する。  [0106] Six optical fibers 88 are arranged on both end faces 96a of the light guide 96, respectively. The optical fiber 88 can allow light emitted from an LED (not shown) to enter the light guide 96 from the end face 96a of the light guide 96. In the light guide 96 having such a structure, since the wall surface constituting the U-shaped groove 96c is inclined with respect to the optical axis of the incident light, the incident light is reflected by the wall surface of the U-shaped groove 96c, The light enters the light guide plate 90 through the parallel grooves 90 f of the light guide plate 90. The light is then reflected from the inclined back surface of the light guide plate 90 and then emitted from the light exit surface.
[0107] 図 18A、図 18B、図 20A及び図 20Bでは、棒状の導光体の両端面から光ファイバ の光を入射させるタイプの面状照明装置を示したが、棒状の導光体の一方の端面の み力も光を入射させるタイプの面状照明装置を構成することもできる。図 22A、図 22 B及び図 24A、図 24Bに、そのような面状照明装置に用いられる導光板 (第 1導光体 )の概略構成図を示した。図 22Aは、図 18A及び図 18Bに示した導光板 18と同様に 、長さ方向に垂直な断面が三角形状の平行溝に導光体が収容されている導光板の 模式的断面図であり、図 21Bは、その導光板を背面側力 見た模式的下面図である 。図 23には、このような導光板 18の平行溝に収容され、一方の端面 98aのみ力 光 を入射させる場合の導光体 98の模式的斜視図を示した。一方の端面 98aのみから 光を入射させる場合の導光体 98は、図 23に示すように、光を入射させる側の端面 9 8aから他方の端面 98dに向力うに従って幅が広がり、且つ深さが深くなるような V字 状の溝 98cを下面 98bに有する。また、このような導光体 98の V字状の溝を構成する 壁面には、前述した導光体と同様に、プリズム列を形成することができる。導光体 98 の V字溝 98cの断面積の小さい側の端面 98a側には光ファイバ 88が配置される。導 光体 98をこのような構造で形成することにより、導光体 98の端面 98aに配置された光 ファイバからの光は、導光体 98の V字溝 98cの壁面のプリズム列において反射して 導光板 18の平行溝 18fから内部に入射し、導光板 18の傾斜背面 18dで反射した後 、光射出面 18aから出射する。 In FIG. 18A, FIG. 18B, FIG. 20A and FIG. 20B, a surface illumination device of a type in which light from an optical fiber is incident from both end faces of a rod-shaped light guide is shown. It is also possible to construct a surface illumination device of a type in which light is incident only on the end face of the light. 22A, 22B, 24A, and 24B show schematic configuration diagrams of a light guide plate (first light guide) used in such a planar illumination device. FIG. 22A is a schematic cross-sectional view of a light guide plate in which a light guide is housed in a parallel groove having a triangular cross section perpendicular to the length direction, similar to the light guide plate 18 shown in FIGS. 18A and 18B. FIG. 21B is a schematic bottom view of the light guide plate as viewed from the rear side. In FIG. 23, only the one end face 98a is accommodated in the parallel groove of the light guide plate 18 as described above. The schematic perspective view of the light guide 98 in the case of entering is shown. As shown in FIG. 23, the light guide 98 in the case where light is incident only from one end surface 98a is widened and deepened as it is directed from the end surface 98a on the light incident side to the other end surface 98d. A V-shaped groove 98c is formed on the lower surface 98b so as to be deep. Further, a prism row can be formed on the wall surface forming the V-shaped groove of the light guide 98 like the light guide described above. An optical fiber 88 is disposed on the end face 98a side of the light guide 98 having the smaller cross-sectional area of the V-shaped groove 98c. By forming the light guide 98 with such a structure, the light from the optical fiber arranged on the end face 98a of the light guide 98 is reflected by the prism row on the wall surface of the V-shaped groove 98c of the light guide 98. Then, the light enters from the parallel groove 18f of the light guide plate 18 and is reflected by the inclined back surface 18d of the light guide plate 18, and then exits from the light exit surface 18a.
[0108] また、図 24A及び図 24Bには、それぞれ、長さ方向に垂直な断面が楕円の一部を 取り除いたような形状の平行溝 90fに導光体が収容されている導光板 90の模式的断 面図と、その導光板 90を背面側から見た模式的下面図を示した。また、図 25には、 そのような導光板 90の平行溝 90fに収容され、一方の端面のみ力 光を入射させる 導光体 99の模式的斜視図を示した。図 25に示すように、一方の端面 99aのみから 光を入射させる場合の導光体 90は、光を入射させる側の端面 99aから他方の端面 9 9dに向かうに従って幅が広がり、且つ、深さが深くなるような U字状の溝 99cを下面 9 9bに有する。図示例では、導光板 90の U字溝 99cは、長さ方向に垂直な断面形状 が楕円の一部を取り除いたような形状になるように形成されている。また、導光体 99 の U字溝 99cの壁面にはプリズム列を形成することができる。導光体 99をこのような 構造で形成することにより、導光体 99の端面 99aに配置された光ファイバ 88からの 光を、導光体 99の V字溝 99cの壁面のプリズム列において反射させて導光板 90の 内部に入射させ、導光板 90の傾斜背面 90dで反射させた後、光射出面 90aから出 射させることができる。 [0108] Also, in FIGS. 24A and 24B, the light guide plate 90 in which the light guide is housed in the parallel grooves 90f each having a cross-section perpendicular to the length direction with a part of an ellipse removed. A schematic cross-sectional view and a schematic bottom view of the light guide plate 90 viewed from the back side are shown. FIG. 25 shows a schematic perspective view of the light guide 99 that is accommodated in the parallel groove 90f of the light guide plate 90 and in which force light is incident only on one end face. As shown in FIG. 25, the light guide 90 in the case where light is incident only from one end surface 99a has a width that increases from the end surface 99a on the light incident side toward the other end surface 99d and has a depth. A U-shaped groove 99c is formed on the lower surface 99b so as to be deeper. In the illustrated example, the U-shaped groove 99c of the light guide plate 90 is formed such that a cross-sectional shape perpendicular to the length direction is a shape obtained by removing a part of an ellipse. A prism row can be formed on the wall surface of the U-shaped groove 99c of the light guide 99. By forming the light guide 99 with such a structure, the light from the optical fiber 88 arranged on the end face 99a of the light guide 99 is reflected by the prism row on the wall surface of the V-shaped groove 99c of the light guide 99. The light is incident on the inside of the light guide plate 90, reflected by the inclined back surface 90d of the light guide plate 90, and then emitted from the light exit surface 90a.
[0109] つぎに、本発明に従う面状照明装置の更に別の構成例として、導光板 (第 1導光体 )の平行溝に導光体 (第 2導光体)を設けずに、導光板の端面から光を入射させるタ イブの面状照明装置について説明する。図 26Aに、面状照明装置に用いられる導 光板 102の模式的断面図を示し、図 26Bに、 B— B線矢視図を示し、図 26Cに、図 2 6Aに示した導光板を背面側力 見た模式的下面図を示した。導光板 102の傾斜背 面 102bの間の略中央部分には、端面 102から中央に向力 に従って徐々に深くな るような V字状の溝 102cが形成されている。 V字溝 102cを構成する壁面にはプリズ ム列が形成されており、プリズム列は、導光板 102の端面力も入射した光を、その入 射方向に対して垂直な方向に反射させることができる。プリズム列で反射した光は、 傾斜背面 102bに達し、その傾斜背面 102bで反射されて光射出面 102aから出射す る。 Next, as still another configuration example of the planar lighting device according to the present invention, a light guide (second light guide) is not provided in the parallel groove of the light guide plate (first light guide), and the light is guided. The type of planar illumination device that makes light incident from the end face of the optical plate will be described. FIG. 26A shows a schematic cross-sectional view of the light guide plate 102 used in the planar lighting device, FIG. 26B shows a BB line arrow view, FIG. 26C shows FIG. A schematic bottom view showing the rear side force of the light guide plate shown in 6A is shown. A V-shaped groove 102c is formed at a substantially central portion between the inclined back surfaces 102b of the light guide plate 102 so as to gradually deepen from the end surface 102 to the center according to the directional force. A prism array is formed on the wall surface that forms the V-shaped groove 102c, and the prism array can reflect the light incident on the end face force of the light guide plate 102 in a direction perpendicular to the incident direction. . The light reflected by the prism array reaches the inclined back surface 102b, is reflected by the inclined back surface 102b, and exits from the light exit surface 102a.
[0110] また、図 27A〜図 27Cには、第 2導光体を有しない面状照明装置に用いられる導 光板の別の構成例として、楕円の一部を取り除いたような断面形状を有する溝が背 面に形成された導光板 104の模式的断面図と、その B— B線矢視図と、その導光板 1 04を背面側から見た模式的下面図をそれぞれ示した。図 27A〜図 27Cに示すよう に、傾斜背面 104bの略中央部分に、端面 104dから中央に向力 に従って徐々に深 くなるとともに、長さ方向に垂直な断面形状が U字状の溝 104cが形成されている。ま た、溝の壁面にはプリズム列が形成されている。プリズム列は、上述したように、導光 板 104の端面 104dから入射した光を、その入射方向に対して垂直な方向に反射さ せることができる。  [0110] Further, in FIGS. 27A to 27C, as another configuration example of the light guide plate used in the planar lighting device having no second light guide, it has a cross-sectional shape in which a part of an ellipse is removed. A schematic cross-sectional view of the light guide plate 104 in which the groove is formed on the back surface, a BB line arrow view thereof, and a schematic bottom view of the light guide plate 104 viewed from the back side are shown. As shown in FIGS. 27A to 27C, a groove 104c having a U-shaped cross section perpendicular to the length direction is formed at the substantially central portion of the inclined rear surface 104b, gradually increasing in depth from the end surface 104d to the center. Is formed. A prism array is formed on the wall surface of the groove. As described above, the prism row can reflect the light incident from the end face 104d of the light guide plate 104 in a direction perpendicular to the incident direction.
[0111] 上記例では、導光板の両方の端面力 光を入射させるタイプの面状照明装置に用 いられる導光板の構成例を示したが、つぎに、一方の端面力 光を入射させるタイプ の面状照明装置に用いられる導光板の構成例について説明する。一方の端面から 光を入射させる場合の導光板は、光入射側の一方の端面から他方の端面に向かう に従って深くなるような溝が、傾斜背面の間の略中央部分に形成される。図 28Aに は、溝の断面形状が V字状の導光板の模式的断面図を、図 28Bには、図 28Aに示 した導光板の B— B線矢視図を、図 28Cには、図 28Aに示した導光板を背面側から 見た模式的下面図をそれぞれ示した。また、図 29A、図 29B及び図 29Cには、楕円 の一部を切断したような U字状の場合の導光板の模式的断面図と、 B— B線矢視図 と、模式的下面図を示した。これらの導光板 106、 108において、溝 106c、 108cの 壁面には、端面 106d、 108dから入射する光を、その入射方向に対して略垂直な方 向に反射させるためのプリズム列を形成することができる。図 28A及び図 28B並びに 図 29A及び図 29Bに示した何れの導光板 106、 108も、光ファイバ 88により端面 10 6d、 108dから入射する入射光の光軸に対して、溝 106c、 108cを構成する壁面が 傾斜しているので、入射光はその壁面に形成されているプリズム列によって反射し、 導光板 106、 108の傾斜背面 106b、 108bで反射した後、光射出面 106a、 108aか ら出射することになる。 [0111] In the above example, the configuration example of the light guide plate used in the planar illumination device of the type in which both end face force lights of the light guide plate are incident is shown. Next, the type in which one end face force light is incident is shown. A configuration example of a light guide plate used in the planar illumination device will be described. In the light guide plate in which light is incident from one end face, a groove that becomes deeper from one end face on the light incident side toward the other end face is formed at a substantially central portion between the inclined rear faces. 28A shows a schematic cross-sectional view of a light guide plate having a V-shaped groove cross-section, FIG. 28B shows a view taken along the line B-B of the light guide plate shown in FIG. 28A, and FIG. A schematic bottom view of the light guide plate shown in FIG. 28A viewed from the back side is shown. 29A, 29B, and 29C show a schematic cross-sectional view of the light guide plate in the case of a U-shape obtained by cutting a part of an ellipse, a BB line arrow view, and a schematic bottom view. showed that. In these light guide plates 106 and 108, prism walls are formed on the wall surfaces of the grooves 106c and 108c to reflect light incident from the end faces 106d and 108d in a direction substantially perpendicular to the incident direction. Can do. 28A and 28B and In any of the light guide plates 106 and 108 shown in FIGS. 29A and 29B, the wall surfaces constituting the grooves 106c and 108c are inclined with respect to the optical axis of the incident light incident from the end faces 106d and 108d by the optical fiber 88. Therefore, the incident light is reflected by the prism row formed on the wall surface, is reflected by the inclined rear surfaces 106b and 108b of the light guide plates 106 and 108, and then exits from the light exit surfaces 106a and 108a.
[0112] つぎに、本発明の棒状照明装置をタンデム方式に従う面状照明装置に用いた例に ついて説明する。図 30A、図 30B及び図 30Cに、本発明の棒状照明装置を備えた タンデム方式の面状照明装置の導光板の概略断面図と、その部分拡大断面図と、そ の導光板を、反射フィルムを取り除いた状態で背面側から見た模式的下面図を示す  [0112] Next, an example in which the bar lighting device of the present invention is used in a planar lighting device according to a tandem method will be described. 30A, 30B, and 30C are a schematic cross-sectional view of a light guide plate of a tandem type planar lighting device including the rod-shaped lighting device of the present invention, a partially enlarged cross-sectional view thereof, and the light guide plate as a reflective film. Shows a schematic bottom view seen from the back side with the
[0113] タンデム方式の面状照明装置 210は、図 30Bに示すように、断面がくさび型の複数 の導光板 120と、棒状照明装置 122と、反射フィルム 124とを有する。また、棒状照 明装置 122は、図 30B及び図 30Cに示すように、棒状の導光体 130、光ファイバ 13 2及びコリメータ 134を有する。棒状照明装置 122の導光体 130は、導光板 120の肉 厚側の側壁面 120bに対面するように配置される。導光体 130は、図 30Bに示すよう に、導光板 120の肉厚側の側壁面 120bと対面する側が曲面で形成されており、この 曲面側から光を出射することができる。一方、図 30Cに示すように、導光体 130の曲 面側とは反対の側の面 130bは、端面から中央に向力 に従って、曲面側に向かって 傾斜するような傾斜面になっている。また、反射フィルム 124は、導光板 120の傾斜 背面 120cと、棒状照明装置 122の導光体 130を覆うように設けられている。 [0113] As shown in FIG. 30B, the tandem planar illumination device 210 includes a plurality of light guide plates 120 having a wedge-shaped cross section, a rod-like illumination device 122, and a reflection film 124. Moreover, the rod-shaped illumination device 122 includes a rod-shaped light guide 130, an optical fiber 132, and a collimator 134 as shown in FIGS. 30B and 30C. The light guide 130 of the rod-shaped illuminating device 122 is disposed so as to face the side wall surface 120b on the thick side of the light guide plate 120. As shown in FIG. 30B, the light guide 130 is formed with a curved surface on the side facing the thick side wall surface 120b of the light guide plate 120, and light can be emitted from the curved surface side. On the other hand, as shown in FIG. 30C, the surface 130b on the side opposite to the curved surface side of the light guide 130 is an inclined surface that inclines toward the curved surface side according to the direction force from the end surface to the center. . Further, the reflection film 124 is provided so as to cover the inclined back surface 120c of the light guide plate 120 and the light guide 130 of the rod-like lighting device 122.
[0114] 光ファイバ 132の一方の端部は、図示しない光源と接続されており、他方の端部は 、棒状照明装置 122を構成する導光体 130の端面 130a側に配置される。導光体 13 0の端面 130aと光ファイバ 132の間にはコリメータ 134が設けられている。  [0114] One end of the optical fiber 132 is connected to a light source (not shown), and the other end is disposed on the end surface 130a side of the light guide body 130 constituting the rod-shaped illuminating device 122. A collimator 134 is provided between the end face 130 a of the light guide 130 and the optical fiber 132.
図 30A〜図 30Cにそれぞれ示したタンデム方式に従う面状照明装置において、光 ファイバ 132を通じて導光体 130の両端面 130aから入射した光は、ほぼ直進して導 光体 130の傾斜面 130bに達する。そして、この傾斜面 130bおいて反射して曲面側 に向かい、その曲面力も導光板 120の肉厚側の側壁面 120bに入射する。導光板 12 0の側壁面 120bから入射した光は、傾斜背面 120cにお 、て反射して光射出面 120 aから出射する。 In the planar illumination device according to the tandem method shown in FIGS. 30A to 30C, light incident from both end faces 130a of the light guide 130 through the optical fiber 132 travels almost straight and reaches the inclined surface 130b of the light guide 130. . Then, the light is reflected on the inclined surface 130 b and travels toward the curved surface side, and the curved surface force also enters the side wall surface 120 b on the thick side of the light guide plate 120. The light incident from the side wall surface 120b of the light guide plate 120 is reflected by the inclined rear surface 120c to be the light exit surface 120. Ejects from a.
[0115] ここでは、面状照明装置に用いる棒状照明装置として、図 30B及び図 30Cに示し たような導光体を有する棒状照明装置を用いたが、前述した図 5に示した形状の導 光体 (第 2導光体) 52を有する棒状照明装置を用いることもできる。そのような棒状照 明装置を用 、たタンデム方式の面状照明装置 220の概略構成を図 31 A〜図 31 Cに それぞれ示した。図 31Aは、タンデム配置された複数の導光板の概略断面図であり 、図 31Bは、その部分拡大断面図であり、図 31Cは、図 31Bに示した導光板を、反 射フィルムを除いた状態で背面側力も見た模式的下面図である。図示例では、棒状 照明装置 126の導光体として、長さ方向に垂直な断面の形状が円形で、両端面から 中央に向かうに従って次第に細くなる形状の導光体 52を用いて 、る。このような導光 体 52を有する棒状照明装置 126を用いても面状照明装置 220を構成することができ る。  [0115] Here, as the rod-shaped illumination device used in the planar illumination device, a rod-shaped illumination device having a light guide as shown in FIGS. 30B and 30C was used. However, the guide having the shape shown in FIG. 5 described above was used. A rod-shaped illuminating device having a light body (second light guide) 52 can also be used. A schematic configuration of a tandem planar illumination device 220 using such a bar illumination device is shown in FIGS. 31A to 31C, respectively. FIG. 31A is a schematic cross-sectional view of a plurality of light guide plates arranged in tandem, FIG. 31B is a partial enlarged cross-sectional view thereof, and FIG. 31C is a light guide plate shown in FIG. 31B except for a reflective film. It is the typical bottom view which looked at back side force in the state. In the illustrated example, a light guide 52 having a circular cross-sectional shape perpendicular to the length direction and gradually narrowing from both end faces toward the center is used as the light guide of the rod-shaped illumination device 126. The planar illumination device 220 can also be configured by using the rod-like illumination device 126 having such a light guide 52.
[0116] 以上、導光体の両方の端面力 光を入射させるタイプの棒状照明装置を用いた面 状照明装置の構成について説明した。つぎに、導光体の一方の端部から光を入射さ せるタイプの棒状照明装置を用いたタンデム方式の面状照明装置の構成例につい て説明する。図 32A〜図 32Cに、そのような面状照明装置 230の構成例を示した。 図 32Aは、面状照明装置 230を構成する、タンデム配置された導光板 120の模式的 断面図であり、図 32Bは、その部分拡大断面図であり、図 32Cは、図 32Bに示した導 光板 140を背面側から見た模式的下面図である。一方の端部力も光を入射させるタ イブの棒状照明装置 128は、図 32Cに示すように、導光体 140と、光ファイバ 132と、 コリメータ 134とを有する。棒状照明装置 128を構成一方の端面 140aから光を入射 させるタイプの導光体 140は、図 32Cに示すように、光が入射する側の端面 140aか ら他方の端面 140cに向かうに従って次第に先細になる形状を有する。図示例では、 導光体 140は、長さ方向に垂直な断面が略半円状であり、導光板の肉厚側の側壁 面に対面する側は曲面に形成され、その反対側の面 140bが平坦に形成されている 。導光体 140の平坦面 140bは、導光板の肉厚側の側壁面に対して傾斜している。  [0116] The configuration of the planar illumination device using the rod-shaped illumination device of the type in which both end face force lights of the light guide are incident has been described above. Next, a configuration example of a tandem type planar illumination device using a rod-like illumination device of a type in which light enters from one end of the light guide will be described. FIG. 32A to FIG. 32C show a configuration example of such a planar illumination device 230. FIG. 32A is a schematic cross-sectional view of the tandem light guide plate 120 that constitutes the planar lighting device 230, FIG. 32B is a partially enlarged cross-sectional view thereof, and FIG. 32C is a lead view shown in FIG. 32B. FIG. 6 is a schematic bottom view of the optical plate 140 as seen from the back side. As shown in FIG. 32C, the rod-shaped illuminating device 128 in which light is incident also on one end portion has a light guide 140, an optical fiber 132, and a collimator 134. As shown in FIG. 32C, the light guide 140 of the type that makes light incident from one end face 140a gradually tapers from the end face 140a on the light incident side toward the other end face 140c. The shape is as follows. In the illustrated example, the light guide 140 has a substantially semicircular cross section perpendicular to the length direction, the side facing the side wall surface on the thick side of the light guide plate is formed as a curved surface, and the opposite surface 140b. Is formed flat. The flat surface 140b of the light guide 140 is inclined with respect to the side wall surface on the thick side of the light guide plate.
[0117] このような構造の面状照明装置においては、面状照明装置の導光体の一方の端部 のみ力も光を入射させるので、面状照明装置の構造を簡単にすることができ、小型化 と低コストィ匕を実現することができる。 [0117] In the planar illumination device having such a structure, light is also incident only on one end of the light guide of the planar illumination device, so that the structure of the planar illumination device can be simplified. Miniaturization And low cost can be realized.
[0118] また、図 33A〜図 33Cには、導光体の一方の端部力 光を入射させるタイプの棒 状照明装置を用いた面状照明装置の別の概略構成を示した。図 33Aは、面状照明 装置 240を構成する、タンデム配置された複数の導光板の模式的断面図であり、図 33Bは、その部分拡大断面図であり、図 33Cは、図 33Bに示した導光板を背面側か ら見た模式的下面図である。図示例では、図 7Cに示したコーン型の導光体 78を用 V、、その導光体 78の直径の大き 、側の端面（大径端面と!/、う） 78aに LED34を配置 した構成である。このようなコーン型の導光体 78を用いた棒状照明装置 129は、前 述したように、導光体 78の側面 78cから光を出射することができる。このような棒状照 明装置 129の導光体 78を、図 33Cに示すように、導光板 120の肉厚側の端面 120b の近傍に配置することによって面状照明装置を構成することができる。  [0118] FIGS. 33A to 33C show another schematic configuration of a planar illumination device using a rod-like illumination device of a type in which one end force light of a light guide is incident. FIG. 33A is a schematic cross-sectional view of a plurality of tandem light guide plates constituting the planar lighting device 240, FIG. 33B is a partially enlarged cross-sectional view thereof, and FIG. 33C is shown in FIG. 33B. FIG. 5 is a schematic bottom view of the light guide plate as viewed from the back side. In the illustrated example, the cone-shaped light guide 78 shown in FIG. 7C is used V, and the LED 34 is arranged on the end face (large diameter end face! /, U) 78a of the light guide 78 with a large diameter. It is a configuration. The rod-shaped illumination device 129 using such a cone-shaped light guide 78 can emit light from the side surface 78c of the light guide 78 as described above. By arranging such a light guide 78 of the rod-shaped illumination device 129 in the vicinity of the end surface 120b on the thick side of the light guide plate 120 as shown in FIG. 33C, a planar illumination device can be configured.
[0119] 以上、棒状照明装置を用いたタンデム型の面状照明装置について説明したが、つ ぎに、このような棒状照明装置を用いないタンデム型の面状照明装置について説明 する。図 34A〜図 34Cに、そのような面状照明装置 250の構成例を示した。図 34A は、タンデム配置された複数の導光板 150の模式的断面図であり、図 34Bは、その 部分拡大断面図であり、図 34Cは、図 34Bに示した導光板 150を背面側から見た模 式的下面図である。本実施形態における面状照明装置は、図 34Bに示すように、導 光板 140と、反射フィルム 124と、光ファイバ 132と、コリメータ 134とを有している。  [0119] The tandem planar illumination device using the rod-shaped illumination device has been described above. Next, a tandem planar illumination device that does not use such a rod-shaped illumination device will be described. FIG. 34A to FIG. 34C show a configuration example of such a planar illumination device 250. 34A is a schematic cross-sectional view of a plurality of light guide plates 150 arranged in tandem, FIG. 34B is a partial enlarged cross-sectional view thereof, and FIG. 34C is a view of the light guide plate 150 shown in FIG. 34B from the back side. It is a schematic bottom view. The planar illumination device in this embodiment includes a light guide plate 140, a reflection film 124, an optical fiber 132, and a collimator 134, as shown in FIG. 34B.
[0120] 導光板 150は、断面がくさび型の形状を有しており、上面が光射出面 150aである。  [0120] The light guide plate 150 has a wedge-shaped cross section, and the upper surface is a light emitting surface 150a.
また、図 34Bに示すように、導光板 150の肉厚側に、光を導光体 150の内部に導くた めの入射部 150bが形成されている。複数の導光板 150は、互いの光射出面が面一 になり、入射部 150bの上面に、他の導光体の薄肉側の先端部分が部分的に重なる ように互いに連結されて配置される。また、導光板 150の入射部 150bの側壁面 150 cは、図 34B及び図 34Cに示すように、その反対側に位置する側壁面 150dに対して 傾斜した形状で形成されている。すなわち、複数の導光板をタンデム配置した方向 における入射部 150bの側壁面 150cが、入射部 150bの垂直な光入射面 (導光板の くさび型の断面形状を有する側の面） 150eに対して垂直に形成されているのではな ぐ斜めになるように形成されている。また、この入射部 150bの傾斜した側壁面 150c にはプリズム列が形成されて！、る。 Further, as shown in FIG. 34B, an incident portion 150b for guiding light to the inside of the light guide 150 is formed on the thick side of the light guide plate 150. The plurality of light guide plates 150 are arranged to be connected to each other such that the light emission surfaces of the light guide plates 150 are flush with each other, and the thin-walled tip portions of the other light guides partially overlap the upper surface of the incident portion 150b. . Further, as shown in FIGS. 34B and 34C, the side wall surface 150c of the incident portion 150b of the light guide plate 150 is formed in a shape inclined with respect to the side wall surface 150d located on the opposite side. That is, the side wall surface 150c of the incident portion 150b in the direction in which the plurality of light guide plates are arranged in tandem is perpendicular to the vertical light incident surface of the incident portion 150b (the surface on the side having the wedge-shaped cross section of the light guide plate) 150e. It is formed to be slanted rather than being formed. Further, the inclined side wall surface 150c of the incident portion 150b A prism row is formed in! RU
[0121] また、導光板 150の入射部 150の光入射面 150eには、図 34B及び図 34Cに示す ように、光ファイバ 132が配置されている。光ファイバ 132は、図示しない LEDからの 光を導光板 150の入射部 150bの光入射面 150eに照射することができる。光フアイ バ 132の光出射側の端部と、導光板 150の入射部 150bの光入射面 150eとの間に はコリメータ 134が設けられている。  Further, as shown in FIGS. 34B and 34C, an optical fiber 132 is disposed on the light incident surface 150e of the incident portion 150 of the light guide plate 150. FIG. The optical fiber 132 can irradiate the light incident surface 150e of the incident portion 150b of the light guide plate 150 with light from an LED (not shown). A collimator 134 is provided between the light emitting side end of the optical fiber 132 and the light incident surface 150e of the incident portion 150b of the light guide plate 150.
[0122] 上記構造を有する導光板 150は、上述したように入射部 150bの側壁面 150cが光 入射面 150eに対して傾斜して形成されて ヽるので、コリメータ 134を介して光入射面 150eに垂直に入射した光ファイバ 132からの入射光は、傾斜した側壁面 150cに形 成されているプリズム列によって薄肉側に反射した後、導光板 150の傾斜背面 150f で更に反射し、光射出面 150aから出射する。  [0122] In the light guide plate 150 having the above-described structure, the side wall surface 150c of the incident portion 150b is formed so as to be inclined with respect to the light incident surface 150e as described above, and therefore, the light incident surface 150e via the collimator 134 is formed. Incident light from the optical fiber 132 incident perpendicularly to the light beam is reflected to the thin wall side by the prism array formed on the inclined side wall surface 150c, and then further reflected on the inclined back surface 150f of the light guide plate 150 to obtain a light exit surface. Emits from 150a.
[0123] 以上、棒状照明装置を用いないタンデム型の面状照明装置の構成例として、導光 板の片側力 光を入射させるタイプの例について説明した。つぎに、導光板の両方 の端面力も光を入射させる場合の構成例について説明する。図 35A〜図 35Cに、両 方の端面 160eから光を入射させる場合の面状照明装置 260の導光板 160の構成 例を示した。図 35Aは、タンデム配置された複数の導光板 160の模式的断面図であ り、図 35Bは、その部分拡大断面図であり、図 35Cは、図 35Bに示した導光板 160を 背面側から見た模式的下面図である。なお、図 35Cでは、構造をわかりやすく示す ために反射フィルムを除 、て 、る。  As described above, the example of the type in which the one-sided force light of the light guide plate is incident has been described as the configuration example of the tandem planar illumination device that does not use the rod-like illumination device. Next, a configuration example in which light is incident on both end face forces of the light guide plate will be described. FIG. 35A to FIG. 35C show configuration examples of the light guide plate 160 of the planar illumination device 260 when light is incident from both end faces 160e. FIG. 35A is a schematic cross-sectional view of a plurality of light guide plates 160 arranged in tandem, FIG. 35B is a partially enlarged cross-sectional view thereof, and FIG. 35C is a view of the light guide plate 160 shown in FIG. 35B from the back side. It is the typical bottom view seen. In FIG. 35C, the reflective film is removed to show the structure in an easy-to-understand manner.
[0124] 導光板 160は、図 35B及び図 35Cに示すように、入射部 160bの側壁面 160cが中 央に向力 に従って、薄肉側の側壁面 160dに向力つて傾斜するように形成されてい る。また、傾斜した入射部 160bの側壁面 160cには、上記と同様に、プリズム列が形 成されている。また、図示例においては、入射部 160bの両方の光入射面 160eに光 ファイバ 132が配置され、光ファイバ 132の端部と光入射部 160bの光入射面 160eと の間にはコリメータ 134がそれぞれ配置されている。このような構造の導光板 160も 同様に、光入射面 160bから入射した光は、入射部 160bの側壁面 160cのプリズム 列によって薄肉側に向力つて反射した後、導光板 160の傾斜背面 160fにおいて更 に反射して、光射出面 160aから出射する。 [0125] 以上、本発明の導光部材、それを用いる面状照明装置、本発明の棒状照明装置 及び液晶表示装置について説明したが、本発明は上記実施態様に限定はされず、 本発明の主旨を逸脱しな 、範囲にぉ 、て、各種の改良や変更をしてもよ!、のはもち ろんである。 [0124] As shown in FIGS. 35B and 35C, the light guide plate 160 is formed such that the side wall surface 160c of the incident portion 160b is inclined toward the thin wall side surface 160d according to the directional force toward the center. The In addition, prism rows are formed on the side wall surface 160c of the inclined incident portion 160b in the same manner as described above. In the illustrated example, optical fibers 132 are disposed on both light incident surfaces 160e of the incident portion 160b, and a collimator 134 is provided between the end of the optical fiber 132 and the light incident surface 160e of the light incident portion 160b. Has been placed. Similarly, in the light guide plate 160 having such a structure, the light incident from the light incident surface 160b is reflected toward the thin wall side by the prism row on the side wall surface 160c of the incident portion 160b and then the inclined back surface 160f of the light guide plate 160. Then, the light is further reflected and emitted from the light exit surface 160a. [0125] Although the light guide member of the present invention, the planar illumination device using the light guide member, the rod-shaped illumination device of the present invention, and the liquid crystal display device have been described above, the present invention is not limited to the above-described embodiments. It goes without saying that various improvements and changes may be made without departing from the spirit of the invention!
例えば、上記実施の形態のタンデム方式に従う面状照明装置においては、複数の 導光板をタンデム配置した構成にしたが、導光板を 1つの部材として一体で形成して ちょい。  For example, the planar lighting device according to the tandem method of the above embodiment has a configuration in which a plurality of light guide plates are arranged in tandem, but the light guide plates may be integrally formed as one member.
また、図 18A、図 18B及び図 20A、図 20Bにおいては、導光板の平行溝に収容さ れる導光体として、溝の形状が V字状及び U字状の形状を示したが、これに限定され ず、円形、放物線、双曲線などの任意の形状にすることができる。  In FIGS. 18A, 18B, 20A, and 20B, as the light guides accommodated in the parallel grooves of the light guide plate, the grooves have V-shaped and U-shaped shapes. The shape can be any shape such as, but not limited to, a circle, a parabola, and a hyperbola.
産業上の利用可能性  Industrial applicability
[0126] 以上、詳細に説明したように、本発明の導光部材および導光板は、点状光源、特に 発光ダイオードが発する光を有効に利用することができ、かつ、冷陰極管を用いた導 光板よりも薄型化や軽量ィ匕することができ、さら〖こ、輝度むらの発生を低減することが できる。このような導光部材および導光板は、液晶パネルのノ ックライトユニットに用 V、られる導光部材および導光板として最適である。  [0126] As described above in detail, the light guide member and the light guide plate of the present invention can effectively use light emitted from a point light source, particularly a light emitting diode, and use a cold cathode tube. It can be made thinner and lighter than the light guide plate, and the occurrence of unevenness and uneven brightness can be reduced. Such a light guide member and a light guide plate are optimal as a light guide member and a light guide plate used for a knock light unit of a liquid crystal panel.
また、本発明の面状照明装置は、上記導光部材または上記導光板を用いるので、 照明用光源として冷陰極管を用いずに、光源の使用波長の調整が可能である発光 ダイオードなどの点状光源を用いることができ、色再現性が高ぐ色再現域の拡大、 彩度の向上を図ることができるとともに、薄型化及び軽量ィ匕を図ることができる。  In addition, since the planar illumination device of the present invention uses the light guide member or the light guide plate, the use wavelength of the light source can be adjusted without using a cold cathode tube as the illumination light source. The light source can be used, the color reproduction range with high color reproducibility can be expanded, the saturation can be improved, and the thickness and weight can be reduced.
[0127] さらに、本発明の棒状照明装置は、柱状の導光体の両端面力 LEDなどの点状光 源の光を入射させて、その入射光を側壁力 出射することができるので、面状照明装 置の冷陰極管の代わりに用いることができる。特に、導光体の形状を所望の形状に 加工することができるので、薄型の導光板を有する面状照明装置の光源として最適 である。更に、点状光源として擬似白色 LED又は RGB— LEDを用いることができる ので、色再現性が高ぐ色再現域の拡大、彩度の向上を図ることができる。  [0127] Furthermore, the bar-shaped illuminating device of the present invention allows the light from a point light source such as a double-sided force LED of a columnar light guide to be incident and emits the incident light with a sidewall force. It can be used in place of the cold cathode tube of the lighting device. In particular, since the shape of the light guide can be processed into a desired shape, it is optimal as a light source for a planar illumination device having a thin light guide plate. Furthermore, since a pseudo white LED or RGB-LED can be used as the point light source, it is possible to expand the color reproduction range and improve the saturation with high color reproducibility.
本発明の面状照明装置は、導光板としていわゆるタンデム型の導光板を用い、照 明用光源として冷陰極管を用いずに、上記の棒状照明装置を用いているので、色再 現性が高ぐ色再現域の拡大、彩度の向上を図ることができるとともに、薄型化及び 軽量ィ匕を図ることができる。 The planar illumination device of the present invention uses a so-called tandem light guide plate as the light guide plate, and uses the above bar illumination device without using a cold cathode tube as the illumination light source. It is possible to expand the color reproduction range with high actuality and improve the saturation, and to reduce the thickness and weight.

Claims

請求の範囲 The scope of the claims
[1] 透明な導光部材であって、  [1] A transparent light guide member,
矩形状光射出面を有し、前記矩形状光射出面と反対側に位置する背面に前記矩 形状光射出面の一辺に平行な平行溝が形成された透明な板状の第 1導光体と、 前記平行溝内に収容される柱状の外形を有する透明な第 2導光体とから構成され る導光部材。  A transparent plate-shaped first light guide having a rectangular light exit surface and having a parallel groove parallel to one side of the rectangular light exit surface on a back surface opposite to the rectangular light exit surface And a transparent second light guide having a columnar outer shape housed in the parallel groove.
[2] 前記第 2導光体は、前記平行溝と略同形状の断面形状を有して構成されて!、る請 求項 1に記載の導光部材。  [2] The light guide member according to claim 1, wherein the second light guide has a cross-sectional shape substantially the same as the parallel groove.
[3] 前記第 2導光体は、一方の端面力 他方の端面に向かうに従って外径力 S小さくなる 形状を有する 1組の導光体を、その外径の小さい側の端面同士を接続した形状を有 して構成されている請求項 1又は 2に記載の導光部材。  [3] The second light guide has a shape in which the outer diameter force S decreases toward one end face force toward the other end face, and a pair of light guides having the outer diameter side connected to each other. The light guide member according to claim 1 or 2, wherein the light guide member has a shape.
[4] 前記第 1導光体の背面は、前記平行溝の中心軸を含み前記矩形状光射出面に垂 直な面に対して対称な 1対の傾斜背面を有し、前記傾斜背面は、それぞれ、前記中 心軸部分力 前記一辺に直交する方向の端部に向かうに従って肉厚が薄くなるよう に前記矩形状光射出面に対して傾斜している単数もしくは複数の構造が前記薄肉 部で連結された形状である請求項 1〜3のいずれか一項に記載の導光部材。  [4] The back surface of the first light guide has a pair of inclined back surfaces that include a central axis of the parallel grooves and are symmetrical with respect to a surface perpendicular to the rectangular light exit surface. Each of the thin-walled portions includes one or more structures that are inclined with respect to the rectangular light exit surface so that the thickness decreases toward the end in the direction orthogonal to the one side. The light guide member according to any one of claims 1 to 3, wherein the light guide member has a shape connected with each other.
[5] 前記第 2導光体の前記平行溝から露出する露出面が、前記矩形状光射出面に対 して傾斜して 、る請求項 1〜4の 、ずれか一項に記載の導光部材。  [5] The guide according to any one of claims 1 to 4, wherein an exposed surface exposed from the parallel groove of the second light guide is inclined with respect to the rectangular light exit surface. Light member.
[6] 前記第 2導光体の前記露出面にプリズム列が形成されている請求項 5に記載の導 光部材。  6. The light guide member according to claim 5, wherein a prism row is formed on the exposed surface of the second light guide.
[7] 前記第 2導光体の長さ方向に垂直な断面形状が、三角形状、円形状、楕円の一部 を切断した形状、又は放物線の一部の形状である請求項 1〜6のいずれか一項に記 載の導光部材。  7. The cross-sectional shape perpendicular to the length direction of the second light guide is a triangle, a circle, a shape obtained by cutting a part of an ellipse, or a shape of a part of a parabola. The light guide member as described in any one of Claims.
[8] 前記第 2導光体は、長さ方向における両方の端面から光が入射され、前記両方の 端面から中央に向かうに従って幅が広くなるとともに深さが深くなる溝を有する請求 項 1〜7のいずれか一項に記載の導光部材。  [8] The second light guide has a groove in which light is incident from both end faces in the length direction and becomes wider and deeper from the both end faces toward the center. 8. The light guide member according to any one of 7.
[9] 前記第 2導光体は、長さ方向における一方の端面力 光が入射され、光が入射す る側の前記端面力 他方の端面に向かうに従って幅が広くなるとともに深さが深くな る溝を有する請求項 8に記載の導光部材。 [9] The second light guide is incident on one end surface force light in the length direction, and becomes wider and deeper toward the other end surface of the end surface force on the light incident side. The light guide member according to claim 8, further comprising a groove.
[10] 前記第 2導光体の前記溝は V字状または U字状の溝である請求項 8又は 9に記載 の導光部材。 10. The light guide member according to claim 8, wherein the groove of the second light guide is a V-shaped or U-shaped groove.
[11] 請求項 1〜10のいずれか一項に記載の導光部材と、  [11] The light guide member according to any one of claims 1 to 10,
点状光源とを有し、  A point light source,
前記第 2導光体の両端面から前記点状光源からの光が入光される面状照明装置。  A planar illumination device in which light from the point light source enters from both end faces of the second light guide.
[12] 前記点状光源が前記第 2導光体の両端面に配置されている請求項 11に記載の面 状照明装置。 12. The planar illumination device according to claim 11, wherein the point light source is disposed on both end faces of the second light guide.
[13] 更に、前記点状光源からの光を前記第 2導光体の端面に導くためのライトガイドを 有する請求項 11に記載の面状照明装置。  13. The planar illumination device according to claim 11, further comprising a light guide for guiding light from the point light source to an end surface of the second light guide.
[14] 前記点状光源が、 LEDである請求項 11〜13のいずれか一項に記載の面状照明 装置。 [14] The planar illumination device according to any one of [11] to [13], wherein the point light source is an LED.
[15] 前記 LEDが、擬似白色 LED又は RGB— LEDである請求項 14に記載の面状照明 装置。  15. The planar lighting device according to claim 14, wherein the LED is a pseudo white LED or an RGB-LED.
[16] 棒状照明装置であって、  [16] A bar lighting device,
点状光源と、  A point light source;
柱状の形状を有し、両端面力 中央に向かうに従って外径が小さくなる導光体とを 有し、  A light guide having a columnar shape and having an outer diameter that decreases toward the center of the force at both end faces;
前記導光体の両端から前記点状光源の光を入射させて、その入射した光を前記導 光体の側壁から出射する棒状照明装置。  A rod-shaped illuminating device in which light from the point light source is incident from both ends of the light guide and the incident light is emitted from a side wall of the light guide.
[17] 前記導光体は、一方の端面力 他方の端面に向かうに従って外径力 、さくなる形 状を有する一組の導光体を、それら導光体の外径の小さい端面同士が互いに密着 して構成されている請求項 16に記載の棒状照明装置。 [17] The light guide includes a pair of light guides having a shape in which the outer diameter force decreases toward one end face force toward the other end face. 17. The rod-shaped lighting device according to claim 16, wherein the lighting device is in close contact.
[18] 矩形状光射出面を有し、前記矩形状光射出面と反対側に位置する背面の中央部 分に前記矩形状光射出面の一辺に平行な平行溝が形成された透明な導光板を有 する面状照明装置に用いられ、 [18] A transparent guide having a rectangular light exit surface, and having a parallel groove formed parallel to one side of the rectangular light exit surface at the center of the back surface located on the opposite side of the rectangular light exit surface. Used for planar lighting devices with light plates,
前記導光体が、前記導光板の平行溝と略同形状の外形を有し、かつ前記平行溝 内に配置される請求項 16又は 17に記載の棒状照明装置。 The rod-shaped illumination device according to claim 16 or 17, wherein the light guide has an outer shape substantially the same shape as a parallel groove of the light guide plate, and is disposed in the parallel groove.
[19] 前記導光体の側面のうち、前記導光板の前記平行溝を形成する側壁と対向する側 面以外の側面にプリズム列が形成されている請求項 18に記載の棒状照明装置。 19. The rod-shaped illuminating device according to claim 18, wherein a prism row is formed on a side surface of the light guide body other than a side surface facing the side wall forming the parallel groove of the light guide plate.
[20] 前記導光体の軸方向に垂直な断面形状が、三角形状、円形状、楕円の一部を切 断した形状、又は放物線の一部の形状である請求項 16〜19のいずれか一項に記 載の棒状照明装置。  [20] The cross-sectional shape perpendicular to the axial direction of the light guide is a triangular shape, a circular shape, a shape obtained by cutting a part of an ellipse, or a shape of a part of a parabola. The bar-shaped lighting device described in one item.
[21] 更に、前記点状光源が発する光を前記導光体の端面に導くためのライトガイドを備 える請求項 16〜20のいずれか一項に記載の棒状照明装置。  21. The rod-shaped illuminating device according to any one of claims 16 to 20, further comprising a light guide for guiding light emitted from the point light source to an end face of the light guide.
[22] 前記点状光源が、 LEDである請求項 16〜21のいずれか一項に記載の棒状照明 装置。 [22] The rod-shaped lighting device according to any one of claims 16 to 21, wherein the point light source is an LED.
[23] 前記 LEDが、擬似白色 LED又は RGB— LEDである請求項 22に記載の棒状照明 装置。  23. The rod-shaped lighting device according to claim 22, wherein the LED is a pseudo white LED or an RGB-LED.
[24] 前記 RGB— LEDは、順次パルス点灯する請求項 23に記載の棒状照明装置。  24. The rod-shaped lighting device according to claim 23, wherein the RGB-LEDs are sequentially pulse-lit.
[25] 面状照明装置であって、 [25] A planar lighting device,
請求項 16〜24のいずれか一項に記載の棒状照明装置と、  A rod-shaped lighting device according to any one of claims 16 to 24,
矩形状光射出面と、前記矩形状光射出面の一辺から、当該一辺に向かい合う対辺 に向力つて板厚が薄くなるように、前記矩形状光射出面に対して傾斜する傾斜背面 とを有する複数の透明な導光板とを有し、  A rectangular light emitting surface, and an inclined back surface that is inclined with respect to the rectangular light emitting surface so that the plate thickness is reduced from one side of the rectangular light emitting surface toward the opposite side facing the one side. A plurality of transparent light guide plates,
前記複数の導光板は、前記矩形状光射出面が同一平面を形成するとともに、前記 一辺を含む側面が、前記対辺を含む側面と接するように配列されており、  The plurality of light guide plates are arranged such that the rectangular light exit surfaces form the same plane, and a side surface including the one side is in contact with a side surface including the opposite side,
前記傾斜背面と前記一辺を含む側面とによって形成される空間に、前記棒状照明 装置の導光体が配置されている面状照明装置。  A planar illumination device in which a light guide of the rod-shaped illumination device is disposed in a space formed by the inclined back surface and a side surface including the one side.
[26] 透明な導光板であって、 [26] A transparent light guide plate,
矩形状の光射出面と、  A rectangular light exit surface;
前記光射出面と反対側に位置し、前記光射出面の一辺に平行な溝が略中央に形 成されている背面とを有し、  A back surface that is located on the opposite side of the light exit surface and that has a groove formed substantially in the center and parallel to one side of the light exit surface;
前記溝は、両方の端面力 中央に向かうに従って次第に溝深さが深くなるとともに 溝幅が広くなる形状を有する導光板。  The light guide plate has a shape in which the groove has a groove depth that gradually increases as the depth toward the center of both end face forces increases.
[27] 透明な導光板であって、 矩形状の光射出面と、 [27] A transparent light guide plate, A rectangular light exit surface;
前記光射出面と反対側に位置し、前記光射出面の一辺に平行な溝が略中央に形 成されている背面とを有し、  A back surface that is located on the opposite side of the light exit surface and that has a groove formed substantially in the center and parallel to one side of the light exit surface;
前記溝は、一方の端面力 他方の端面に向かうに従って次第に溝深さが深くなると ともに溝幅が広くなる形状を有する導光板。  The groove has a shape in which the groove depth gradually increases and the groove width becomes wider toward one end face force toward the other end face.
[28] 前記溝を挟んで両側に位置する前記背面は、前記光射出面に対して傾斜している 請求項 26又は 27に記載の導光板。  [28] The light guide plate according to claim 26 or 27, wherein the back surfaces located on both sides of the groove are inclined with respect to the light exit surface.
[29] 面状照明装置であって、 [29] A planar lighting device,
請求項 26〜28のいずれか一項に記載の導光板と、  The light guide plate according to any one of claims 26 to 28;
点状光源と、  A point light source;
前記点状光源で発せられた光を前記導光板の端面の前記溝が形成されている部 分に導くための追加の導光部材とを有する面状照明装置。  A planar illumination device comprising: an additional light guide member for guiding light emitted from the point light source to a portion of the end surface of the light guide plate where the groove is formed.
[30] 透明な導光板であって、 [30] A transparent light guide plate,
矩形状光射出面と、前記矩形状光射出面の一辺から、当該一辺に向かい合う対辺 に向力つて板厚が薄くなるように、前記矩形状光射出面に対して傾斜する傾斜背面 と、  A rectangular light emitting surface, and an inclined back surface that is inclined with respect to the rectangular light emitting surface so that the plate thickness is reduced from one side of the rectangular light emitting surface toward the opposite side facing the one side;
前記一辺を含む側面に形成され、前記一辺に垂直な光入射面、及び、当該光入 射面から内部に入射する光を、前記対辺を含む側面側に反射させる傾斜面を含む 光入射部とを有する導光板。  A light incident portion including a light incident surface that is formed on a side surface including the one side and is perpendicular to the one side, and an inclined surface that reflects light incident on the inside from the light incident surface toward the side surface including the opposite side; A light guide plate.
[31] 前記光入射部の前記光入射面は、前記導光板の前記一辺に垂直な両方の端面に 形成されており、前記光入射部の前記傾斜面は、前記両方の端面から中央に向かう に従って傾斜している請求項 30に記載の導光板。 [31] The light incident surface of the light incident portion is formed on both end surfaces perpendicular to the one side of the light guide plate, and the inclined surface of the light incident portion is directed from the both end surfaces toward the center. The light guide plate according to claim 30, wherein the light guide plate is inclined according to the following.
[32] 前記光入射部の前記光入射面は、前記導光板の前記一辺に垂直な 2つの端面の うちの一方の端面に形成されており、前記光入射部の前記傾斜面は、前記一方の端 面力 他方の端面に向かうに従って傾斜している請求項 30に記載の導光板。 [32] The light incident surface of the light incident portion is formed on one end surface of two end surfaces perpendicular to the one side of the light guide plate, and the inclined surface of the light incident portion is the one of the one end surfaces. The light guide plate according to claim 30, wherein the light guide plate is inclined toward the other end surface.
[33] 面状照明装置であって、 [33] a surface illumination device comprising:
請求項 30〜32のいずれか一項に記載の導光板と、  A light guide plate according to any one of claims 30 to 32;
点状光源とを備え、 前記点状光源の光を前記導光板の前記光入射面に照射する面状照明装置。 A point light source, A planar illumination device that irradiates the light incident surface of the light guide plate with light from the point light source.
PCT/JP2005/012504 2004-07-07 2005-07-06 Light guide member, planar lighting apparatus using the light guide member, and bar-like lighting apparatus WO2006004160A1 (en)

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