WO2006054654A1 - Light guide plate - Google Patents
Light guide plate Download PDFInfo
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- WO2006054654A1 WO2006054654A1 PCT/JP2005/021139 JP2005021139W WO2006054654A1 WO 2006054654 A1 WO2006054654 A1 WO 2006054654A1 JP 2005021139 W JP2005021139 W JP 2005021139W WO 2006054654 A1 WO2006054654 A1 WO 2006054654A1
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- WIPO (PCT)
- Prior art keywords
- guide plate
- light guide
- light
- plate according
- angle
- Prior art date
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133524—Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
-
- 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
- G02B6/0036—2-D arrangement of prisms, protrusions, indentations or roughened surfaces
-
- 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
- G02B6/0056—Means for improving the coupling-out of light from the light guide for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
-
- 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
- G02B6/0058—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide
- G02B6/0061—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide to provide homogeneous light output intensity
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133504—Diffusing, scattering, diffracting elements
Definitions
- the present invention relates to a light guide plate used in a backlight device that irradiates a liquid crystal display element or the like from the back and a backlight device including a powerful light guide plate.
- a light guide plate that guides light emitted from a light source to a liquid crystal display device
- a knock light device that includes the light guide plate and illuminates the liquid crystal display device from the back side.
- FIG. 1 is a schematic diagram showing an external appearance of the liquid crystal display device 10.
- 1 is a light guide plate
- 2 is a light source
- 3 is an exit surface
- 4 is a reflection surface
- 5 is an entrance surface
- 6 is a deflection pattern element
- 7 is a liquid crystal
- 8 is a reflector
- 9 is an optical sheet
- 11 is a holder.
- 12 are rays
- 13 is the observer's viewpoint.
- the backlight device 14 is a state where the liquid crystal panel is removed from the liquid crystal display device 10.
- the light guide plate 1 also has a transparent material force such as PMMA or polycarbonate, and has a substantially plate-like flat shape.
- One side surface is defined as an incident surface 5, and a deflection pattern is formed on the reflecting surface 4 by a plurality of deflection pattern elements 6 in order to reflect or deflect the light incident from the incident surface 5 toward the exit surface 3.
- the light guide plate 1 is disposed below the liquid crystal panel 7 and is disposed such that the light exit surface 3 of the light guide plate 1 and the lower surface of the liquid crystal panel 7 face each other.
- the light beam 12 emitted from the light source 2 enters the light guide plate 1 from the incident surface 5, travels inside the light guide plate, and rises in the direction of the output surface 3 by the deflection pattern element 6 formed on the reflection surface 4.
- the light exits from the exit surface 3.
- the light guide plate 1 that emits light incident from the incident surface 5 on the side surface from the output surface 3 on the main surface is referred to as a side edge method, and is widely used in mobile phones and the like (for example, Japanese Patent No. 3151830). Issue).
- a hologram obtained by exposing a photosensitive film through a rectangular opening having a diffuser to form a large number of speckles at random (for example, US Pat. No. 5,365). No. 354 and U.S. Pat.No. 5,534,386. See).
- the speckle has a substantially elliptical shape, and the major and minor axes of the ellipse have a relationship of Fourier transform with the short and long sides of the rectangular opening.
- the laser light is scattered by each speckle and reproduces the rectangular opening used for the exposure.
- incident light can be diffused anisotropically.
- the deflection pattern element is generally a dodd pattern 15 as shown in FIG. 2 (a).
- the deflection pattern element is an independent almost circular pattern, the light reflected by the deflection pattern element is not emitted in a certain direction as shown in Fig. 2 (b). There was a problem that it was difficult to increase
- a light guide plate provided with a substantially V-shaped deflection pattern element as shown in FIG. 3 (a) has become mainstream.
- This V-shaped grooved deflection element is generally provided so that the direction of the V-shaped groove is parallel to the incident surface as shown in the top view of FIG.
- FIG. 5 (b) is a side view of FIG. 5 (a) viewed from the direction of the light source 2.
- FIG. 5 (b) is a side view of FIG. 5 (a) viewed from the direction of the light source 2.
- FIG. 5 (b) Light from the light source 2 enters the light guide plate 1 from the incident surface 5.
- the reflection groove is a straight line as in the conventional light guide plate, among the light beams emitted from the light source 2, the light beam 12a becomes a light beam locus deflected in the front direction by the prism film 10 disposed on the upper surface.
- the light beam 12b (oblique light) is largely deflected by the linear reflecting surface, and the ray trajectory force that can be deflected in the front direction by the prism film 10 is also released, so that a portion with a small amount of light emission is generated. Was observed in the dark.
- the present invention has been proposed in view of the above-described circumstances, and brightness brightness / darkness in the vicinity of an incident surface is proposed. It is an object of the present invention to provide a backlight device including a light guide plate that prevents the occurrence of light and a powerful light guide plate.
- both the light rays 12a and 12b can be easily guided in the front direction by the deflection of the prism film disposed on the upper surface. It is possible to prevent brightness contrast in the vicinity of the incident surface, which is a difficult point.
- An embodiment of the present invention is a plate-shaped light guide plate having an incident surface on a side surface and an output surface on an upper surface or a lower surface, and a plurality of light guide plates on the output surface or the surface facing the output surface.
- a deflection pattern element is arranged, and the deflection pattern element has a quadrangular pyramid shape integrally formed on the light guide plate with four surface forces other than the bottom surface of the quadrangular pyramid.
- the area of each of the first surface and the second surface is 20 times or more of the area of each of the adjacent third surface and the fourth surface, and the inclination angles of the first surface and the second surface are The angle is 0.5-3 ° with respect to the exit surface.
- the pattern element has a quadrangular pyramid shape depressed in the light guide plate! / ⁇ .
- the pitch P of the substantially square pyramid deflection pattern elements is constant s.
- the pitch P of the substantially square pyramid deflection pattern elements is indefinite s.
- the pattern element preferably has a quadrangular pyramid bottom surface that is a parallelogram.
- angles ⁇ and ⁇ formed by the sides of the parallelogram are incident surfaces.
- the 0 and the 0 are the same angle.
- the parallelogram is formed by forming a straight line with one side of the parallelogram adjacent to each other among the four sides.
- each of the parallelograms forms a straight line with one side of the adjacent parallelogram.
- the pitch of a straight line group that forms an angle of 0 with the light incident surface P (1), P (2), ⁇ m (m) in order from the surface side, and the straight line group that forms an angle of ⁇ with the incident surface is a straight line group that forms an angle of 0 with the light incident surface P (1), P (2), ⁇ m (m) in order from the surface side, and the straight line group that forms an angle of ⁇ with the incident surface.
- P (n) is preferably all the same value.
- the numerical value of P (n) is preferably set by a random number.
- the intermediate value of the ⁇ and the ⁇ is 30 to 30 respectively.
- the range of the random number is the intermediate value ⁇ 15% or
- a ridge line formed from the first surface and the second surface
- the angle formed by the normal line of the incident surface is preferably within ⁇ 40 °.
- the deflection pattern element is formed on a surface facing the emission surface, and another optical element is formed on the emission surface.
- the other optical element is preferably an optical element having a function of diffusing or condensing emitted light.
- the other optical element has anisotropic diffusibility.
- another embodiment of the present invention is preferably a backlight device including the light guide plate and a liquid crystal display device.
- the light guide plate according to the present invention is a plate-shaped light guide plate having an incident surface on a side surface and an output surface on an upper surface or a lower surface, and a general light guide plate on a surface facing the output surface.
- Deflection pattern elements of roughly quadrangular pyramids formed in a decreasing direction with respect to the wall thickness are arranged adjacent to each other, and the shape of the quadrangular pyramid is formed integrally with the light guide plate except for the bottom surface of the quadrangular pyramid.
- the first and second surfaces are the surfaces of the other third or fourth surface, respectively.
- the ridgeline of the first and second surfaces is orthogonal to the incident surface, and the inclination angle of the first and second surfaces with respect to the exit surface is in the range of 0.5 to 3 degrees.
- the first and second surfaces have approximately the same area, and the third and fourth surfaces have approximately the same area.
- the approximate area means within ⁇ 10% of the intermediate value of the two areas.
- a surface relief hologram is integrally formed on the exit surface side.
- the pitch of the deflection pattern elements having a substantially quadrangular pyramid is constant.
- the pitch of the deflecting pattern elements having a substantially quadrangular pyramid is indefinite.
- the surface relief hologram has a plurality of linear random speckle regions that are long in a direction orthogonal to the incident surface.
- the light diffusing characteristic of the surface relief hologram has a half-value angle of 30 to 70 degrees in the direction parallel to the incident surface, and is irregularly diffused at a half-value angle of 0.5 to 3 degrees in the orthogonal direction. .
- a knocklight device includes the light guide plate having the above-described configuration.
- FIG. 1 is a conceptual diagram showing a conventional light guide plate.
- FIG. 2 is a diagram showing how the conventional light guide plate and backlight device are used.
- FIG. 3 is a conceptual diagram showing a dod pattern deflection pattern element used in a conventional light guide plate.
- FIG. 4 shows a conventional light guide plate with a V-shaped reflection groove.
- FIG. 5 is a diagram in which a prism film is arranged on the upper surface of a conventional light guide plate.
- FIG. 6 is a conceptual diagram for explaining the difference in brightness of a conventional light guide plate.
- FIG. 7 is a conceptual diagram illustrating the light guide plate of the present invention, (a) is a top view of the light guide plate, (b) is a front view of the light guide plate, and (c) is a perspective view of the light guide plate. It is.
- FIG. 8 shows a light guide plate of a type in which a deflection pattern element is recessed.
- FIG. 9 shows a light guide plate of a type in which a deflection pattern element is projected.
- FIG. 10 shows a conventional light guide plate including a straight V-shaped reflection groove method and a deflection pattern element. It is a conceptual diagram.
- FIG. 11 shows a light guide plate of the present invention.
- FIG. 12 is a conceptual diagram showing the operation of the first surface of the light guide plate of the present invention.
- FIG. 13 is a diagram for explaining an interval between deflection pattern elements of the light guide plate of the present invention.
- FIG. 14 is an enlarged view showing details of a hologram formed on the exit surface.
- FIG. 15 is a top view showing a third embodiment of the light guide plate of the present invention.
- FIG. 16 is an enlarged view showing details of a hologram formed on the exit surface.
- FIG. 17 is a schematic view showing an example of a backlight device using the light guide plate of the present invention.
- FIG. 18 is a diagram for explaining the action of a hologram.
- FIG. 19 is a diagram showing an intensity distribution of emitted light.
- FIG. 20 is a view showing a part of a backlight device (or a surface light source device) having a light guide plate and an optical sheet.
- FIG. 21 is a diagram showing an intensity distribution of outgoing light.
- FIG. 22 is a diagram showing a part of the knocklight device.
- the xyz Cartesian coordinate system is set in the figure. That is, the X axis and the y axis are set along the two sides of the upper or lower surface of the light guide plate, and the incident direction of light from the light source is the X axis, and the direction perpendicular thereto is the y axis. Also set the z-axis in the normal direction of the exit surface. Also, the positive and negative directions of the z axis are referred to as up and down.
- FIG. 6 is a perspective view showing a first embodiment of the light guide plate of the present invention.
- FIG. 6 shows one form of arrangement of a light emitting diode (LED), an optical sheet (prism sheet) 6 and a liquid crystal 7 as the light source 2.
- the light guide plate 1 is a plate having a substantially rectangular upper surface and lower surface.
- the material constituting the light guide plate 1 is not particularly limited as long as it is a transparent material having a certain refractive index. Examples thereof include PMMA, polyolefin, polycarbonate, and the like.
- the size of the light guide plate 1 varies depending on the application. For large applications such as 12 or 14-inch displays, 182.9 X 243.8 mm to 213.4 X 284.5 mm, 3 or 8 inch displays, etc. 45.7 X 81.0 mm to 121.9 X 162.6 mm for medium-sized applications, 1 or 2.8 15.2 X 20.3 mm to 42.7 X 56.9 mm for small applications such as 8-inch displays It is about the size.
- the thickness is usually from 0.04 mm to 56.9 mm.
- the incident surface 5 is provided on one side surface of the light guide plate, and the light from the light source 2 is efficiently incident on the light guide plate 1.
- the incident surface 5 is often a flat surface, but a number of fine hairline grooves may be formed as shown in FIG. Such rubbing is preferable in that it is possible to improve luminance unevenness at the incident portion.
- the processing to be formed on the incident surface 5 is not limited to the hairline groove, and conventionally known processing can be performed as necessary.
- FIG. 7 is a drawing showing one shape of the deflection pattern element 17. Further, in FIG. 7, FIG. 7 (a) is a perspective view of the deflection pattern element 17, FIG. 7 (b) is a Vllb-Vllb cross-sectional view, and FIG. 7 (c) is a VIIc-VIIc cross-sectional view. .
- the first and second surfaces 17a and 17b having a large area of the deflection pattern element 17 are mainly used as reflection surfaces for guiding incident light in the direction of the exit surface 3 of the light guide plate 1.
- the first and second surfaces 17a and 17b having a large area are preferably 20 times or more the area of the other third and fourth surfaces, respectively.
- the first and second surfaces 17a and 17b preferably have approximately the same area, and the third and fourth surfaces 17c and 17d preferably have approximately the same area.
- the reflection surface 4 on which the deflection pattern element 17 as in the present embodiment is formed increases the light utilization efficiency of the light guide plate 1 with high efficiency in reflecting incident light in the direction of the emission surface 3.
- the quadrangular pyramid deflection pattern element 17 has a ridge line 18 between the first surface 17a and the second surface 17b. Are arranged so as to face the direction orthogonal to the X-axis direction (X-axis direction).
- the inclination angles of the first surface and the second surface are the inclinations of the third surface and the fourth surface, respectively. Smaller than the corner.
- the first surface and the second surfaces 17a and 17b having a large area of the deflection pattern element 17 are mainly used as reflecting surfaces for guiding the incident light in the direction of the exit surface 3 of the light guide plate 1.
- the first surface 17a and the second surface 17b having a large area are 10 times or more the area of the other third surface and the fourth surface, respectively, and preferably 15 times or more. More preferably.
- the adjacent first surface 17a and second surface 17b have approximately the same area
- the adjacent third surface 17c and fourth surface 17d also have approximately the same area.
- the approximate area means that the difference in area is within twice.
- the light guide plate of the present invention has a deflection pattern having four surface forces other than the bottom surface of the quadrangular pyramid.
- there are two methods for forming four surfaces other than the bottom of the quadrangular pyramid that is, there are two types of such light guide plates.
- One method is to flip the square pyramid in Fig. 7 (a) and press it against the light guide plate to form a deflection pattern. In this way, it is possible to obtain a light guide plate having a shape as shown in FIG. 8 in which a quadrangular pyramid shape in FIG.
- the other is a method of arranging a large number of quadrangular pyramid shapes in FIG. 7 (a) as they are on the light guide plate. In this way, a light guide plate having the shape shown in FIG. 9 can be obtained.
- the first surface 17a and the second surface 17b having a large area are arranged so as to face the direction of the light source, so that the light having the light source power can be deflected in the direction of the emission surface.
- a light guide plate in which a quadrangular pyramid shape is recessed (d-signed) in the light guide plate is advantageous in terms of ease of manufacturing and optical characteristics.
- the light guide plate 1 on which the deflection pattern element 17 as in the present embodiment is formed increases the efficiency of light utilization as a result of the high efficiency of reflecting incident light in the direction of the observer.
- FIG. 10 is a top view of the light guide plate according to the first embodiment of the present invention.
- the quadrangular pyramid deflection pattern element 17 has a ridge line 18 between the first surface 17a and the second surface 17b. Are arranged so as to face a direction (x-axis direction) orthogonal to the incident surface 5. In this way, since the ridge line 18 is aligned in the direction orthogonal to the incident surface 5 (X-axis direction), the outwardly extending shape (square shape) of each deflection pattern element 17 The shape of the bottom of the cone is a rhombus.
- the left-side pitch of the light guide plate 1 (the pitch of the straight line group that forms an angle of 0 with the light incident surface)
- P is expressed as P (1), ⁇ (2), ... ⁇ ( ⁇ ), all ⁇ are equally spaced,
- P (m, n) If the deflection pattern element that also forms the nth pitch force is expressed as P (m, n), P (m, n) has a rhombus shape regardless of the number of m and n.
- the interval between adjacent deflection pattern elements 17 is constant.
- the value of Ps is preferably 30 to 500 m force S, more preferably 100 to 200 / ⁇ ⁇ force S, and further preferably 120 to 160 / ⁇ ⁇ .
- the distance a between the exit surface 3 and the reflection surface 4 of the light guide plate 1 a is preferably 0.3 to 3.
- Omm force S more preferably 0.35 to 0.8 mm force S, and 0. 4 ⁇ 0.8mm force especially preferred! / ⁇ .
- angles (0 and 0) formed by the rhomboid sides of the deflection pattern element and the y-axis are
- FIG. 11 is a cross-sectional view showing a part of the XI-XI cross section of FIG.
- the deflection pattern element 17 has first and second surfaces 17a and 17b and third and fourth surfaces 17c and 17d, which are substantially quadrangular pyramidal reflecting surfaces facing the light source,
- the first surface 17a and the second surface 17b have a predetermined angle ⁇ (inclination angle) with respect to a surface parallel to the emission surface 3.
- ⁇ inclination angle
- the angle formed with the normal can be reduced.
- the gradually raised light is emitted from the emission surface 3 when the angle formed with the normal line of the emission surface 3 is smaller than the critical angle. That is, the light incident on the incident surface 5 of the light guide plate 1 from the light source 2 repeats total reflection at the output surface 3 and the reflection surface 4 until the angle formed with the normal line of the output surface 3 reaches a critical angle, while the light guide plate 1 Go inside.
- the angle a1 formed by the first and second surfaces 17a, 17b and the surface parallel to the emission surface 3 needs to be smaller than the inclination angle oc2 of the third surface and the fourth surface.
- ⁇ is smaller, the light gradually rises due to reflection from the first and second surfaces 17a and 17b, and the exit angle of the exit light from the exit surface 3 (the normal between the exit surface and the exit light). Is always almost equal to the critical angle. Therefore, the directions of light emitted from the emission surface 3 are aligned.
- the angle ⁇ (inclination angle) between the first and second surfaces 17a, 17b and the plane parallel to the exit surface 3 is preferably 0.5 to 3 degrees. The degree is more preferable.
- the angle between the third and fourth surfaces 17c, 17d and the plane parallel to the exit surface 3 (inclination angle between the third surface and the fourth surface) ⁇ 2 has little or no reflection effect. In order to avoid this, it is preferable to make it as large as possible. However, 90 degrees or less is preferable from the viewpoint of facilitating die cutting when the light guide plate 1 described later is formed. In order to achieve the above balance, ⁇ 2 is preferably 50 to 90 degrees, more preferably 55 to 87 degrees.
- the interval Ps between the adjacent deflection pattern elements 17 is constant as shown in FIG.
- the value of Ps is particularly preferably 120 to 160 / ⁇ ⁇ , more preferably 30 to 500 111, more preferably 100 to 200 m.
- the distance a (light guide plate thickness) between the exit surface 3 and the reflection surface 4 of the light guide plate 1 is preferably 0.3 to 3. Omm, and more preferably 0.35 to 0.8 mm. 4 to 0.8 mm is particularly preferable.
- FIG. 13 shows a method for making Ps random.
- FIG. 13 is a plan view of the light guide plate 1 that has been processed so that Ps is random and the reflection surface 4 side force is seen.
- the range of random numbers is preferably within ⁇ 15% of the above intermediate value or within ⁇ 20 / ⁇ .
- the angle formed between the square side of the deflection pattern element and the y-axis is not particularly limited, but it is preferably 0 to 60 ° or more preferably 5 to 40 ° in terms of light utilization efficiency. ⁇ 20 ° is particularly preferred.
- the angle between the sides of the parallelogram and the y-axis is 10 °
- the intermediate value of P and P is 140 / ⁇ ⁇
- each deflection pattern element is 236 to 316 m in the y-axis direction and 41 to 56 m in the x-axis direction.
- the angle ⁇ of the ridgeline is in the range of ⁇ 39.01 ° from the X axis.
- the angle of this ridge is preferably within ⁇ 40 °. In this way, it is expected that moire can be eliminated or reduced because each deflection pattern element shape has abundant randomness.
- the parallelogram (or rhombus) on the bottom of the quadrangular pyramid of the deflection pattern element is such that each of the four sides forms a straight line with one side of the adjacent parallelogram.
- one feature of the light guide plate of the present invention is that a large number of deflection pattern elements shown in FIG. 7 (a) are arranged. Since a light guide plate capable of providing a light device can be obtained, it is not always necessary to arrange as described above. In other words, by slightly shifting the parallelogram, as shown in Fig. 15, only two parallel sides of one side of the parallelogram or rhomboid force form a straight line with one side of the adjacent parallelogram. You may make it become. Such a form is difficult to manufacture as compared to the first and second embodiments, but on the other hand, “shift” gives randomness to the arrangement of the deflection pattern elements, improves appearance, eliminates moire, etc. It is also possible to obtain the effect.
- the polarization pattern element in order to eliminate the dark part near the light source, is a parallelogram or rhombus.
- the deflection pattern element must be a parallelogram or rhombus. There may be no.
- the reflecting groove itself is a force that is a straight line in a direction parallel to the X axis or the y axis.
- an anisotropic diffusion pattern having anisotropy is formed on the exit surface 3.
- This anisotropic diffusion pattern has a light diffusion characteristic of half of 30 to 70 degrees in a direction parallel to the incident surface. More preferably, it is a value angle, and is irregularly diffused at a half-value angle of 0.5 to 3 degrees in the orthogonal direction.
- a hologram is formed as the anisotropic diffusion pattern, and it is particularly preferable that this hologram is a surface relief hologram (in order to distinguish it from a three-dimensionally formed hologram). Called surface relief hologram). In this way, it has a plurality of long and linear random speckle regions in a direction perpendicular to the incident surface.
- the backlight device using the light guide plate of the present invention is as shown in FIG.
- the deflection pattern element 17 of the light guide plate may be provided on the exit surface 3.
- the appearance near the light source 2 tends to be improved, and the luminance tends to be improved. Because, preferred.
- Whether the deflection pattern element 17 is provided on the reflection surface 4 side as in the first embodiment, or whether the deflection pattern element 17 is provided on the emission surface 3 side as in the fourth embodiment, can be freely selected depending on the application. You can choose. For example, when the deflection pattern element 17 is provided on the exit surface 3 side, the appearance near the light source 2 is improved. On the other hand, depending on the prism sheet 6 used, a pattern like water bubbles is observed between the prism sheet 6 and the light guide plate 1. It may be done. On the other hand, in the first embodiment, the brightness and appearance are slightly inferior to those in the fourth embodiment, but since the deflection pattern element 17 is not formed on the exit surface, another processing is performed on the exit surface. Can be applied.
- the exit surface can be roughened to reduce the unevenness of the exit light or to reduce moire.
- the same rough surface processing can also be performed in the fourth embodiment, but the rough surface is arranged at a position farther than the observer's force, so that the effect is improved as compared with the first embodiment. Is inferior.
- an anisotropic diffusion pattern having anisotropy is formed on the surface where the deflection pattern element 17 is not formed. More preferably, the diffusion characteristic is a half-value angle of 30 to 70 degrees in the direction parallel to the incident surface, and an irregular diffusion with a half-value angle of 0.5 to 3 degrees in the orthogonal direction.
- a hologram is formed as the anisotropic diffusion pattern, and it is particularly preferable that this hologram is a surface relief hologram (in order to distinguish it from a three-dimensionally formed hologram). Called surface relief hologram). In this way, it has a plurality of long and linear random speckle regions in a direction perpendicular to the incident surface.
- FIG. 18 and 19 are enlarged views showing details of the hologram 100 formed on the exit surface 3.
- FIG. 18 is an enlarged view of the hologram enlarged 200 times, and FIG. It is an enlarged view.
- FIG. 18 when the hologram is magnified to about 200 times, a large number of linear random speckles or random speckle regions extending in a direction perpendicular to the incident surface 4 (for example, other speckle regions) (Region having higher (or lower) transmittance) than the region (random grooves or irregularities) 100a.
- the random speckle 100a has a random shape and a position that is not constant throughout the hologram.
- the linear speckle 100a causes the light incident on the hologram to be diffused strongly in the direction parallel to the incident surface 5 and weak in the orthogonal direction.
- the diffusion ratio of the diffusivity in the direction parallel to and perpendicular to the incident surface 5 is determined by the major and minor axis dimensions of the speckle.
- the hologram has a function as a diffuser.
- FIG. 20 is a diagram for explaining the operation of the hologram.
- FIG. 20 (a) is a top view showing the angle dependence of the intensity of the light emitted from the points Pl and P2 on the exit surface 3 of the light guide plate 1.
- FIG. 20 (b) is a perspective view showing a three-dimensional intensity distribution of light emitted from the point P2 on the exit surface 3 of the light guide plate 1.
- Points PI, P2 force on the exit surface 3 of the light guide plate 1
- the emitted light is parallel to the entrance surface 5 as shown by ellipses El, E2 by the hologram 100 formed on the exit surface 3.
- the diffusion is strong in the direction and weak in the orthogonal direction.
- FIG. 21 shows the intensity distribution of the emitted light.
- FIG. 21 (a) shows the intensity distribution of the emitted light in the ⁇ direction
- FIG. 21 (b) shows the intensity distribution of the emitted light in the r direction.
- the half-width ⁇ of the diffusion angle ⁇ in the ⁇ direction is strongly diffused in the parallel direction ⁇ compared to the incident surface 5 and the orthogonal direction r, and the diffusion angle ⁇ in the r direction Than half width of ⁇
- the half-value width ⁇ in the r direction is preferably 0.5 ⁇ ⁇ 3 degrees, more preferably 1 ⁇ ⁇ 2 degrees.
- the half-width ⁇ in the ⁇ direction is preferably 30 to 70 degrees, more preferably 45 to 65 degrees.
- the hologram Due to the anisotropic diffusion action of the hologram, a uniform intensity distribution of the emitted light in the 0 direction is realized in the light guide plate 1. In particular, the appearance of bright lines in the light emitted from the exit surface 3 is prevented.
- FIG. 22 is a diagram showing a part of a backlight device (or a surface light source device) having a light guide plate and an optical sheet.
- the light emitted from the light exit surface 3 of the light guide plate 1 is light L having components with small angles ⁇ 1, ⁇ 2 formed by the light exit surface 3.
- the optical sheet 10 has a flat upper surface (10A)
- Light L, L which has a prism-shaped lower surface (10B) and has a small angle with the light exit surface 3 of the light guide plate 1,
- optical sheet are not particularly limited as long as they have a general prism structure.
- examples thereof include M065HS (Mitsubishi Rayon), M168YS (Mitsubishi Rayon), and ⁇ - ⁇ (3 ⁇ ). These can be used singly or in combination of two or more or two or more.
- the backlight device (or surface light source device) can be used as a backlight in a liquid crystal display device such as a mobile phone or an electronic notebook.
- the light source may be a single-chip LED, a 2-chip LED, or a multi-chip LED as long as it is a point light source.
Abstract
Description
Claims
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004-336478 | 2004-11-19 | ||
JP2004336478 | 2004-11-19 | ||
JP2005-228081 | 2005-08-05 | ||
JP2005228081 | 2005-08-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2006054654A1 true WO2006054654A1 (en) | 2006-05-26 |
Family
ID=36407192
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2005/021139 WO2006054654A1 (en) | 2004-11-19 | 2005-11-17 | Light guide plate |
Country Status (3)
Country | Link |
---|---|
KR (1) | KR20070059213A (en) |
TW (1) | TW200622445A (en) |
WO (1) | WO2006054654A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1876388A1 (en) * | 2006-07-04 | 2008-01-09 | Samsung SDI Co., Ltd. | Light guide member and backlight unit including light guide member |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1020125A (en) * | 1996-06-28 | 1998-01-23 | Nitto Denko Corp | Surface light source device and liquid crystal display device |
JP2003066235A (en) * | 2001-08-27 | 2003-03-05 | Sanyo Electric Co Ltd | Light transmission plate and surface light source device using the same |
JP2003098356A (en) * | 2001-09-20 | 2003-04-03 | Pioneer Electronic Corp | Light transmission plate |
JP2004111384A (en) * | 2002-08-30 | 2004-04-08 | Hitachi Chem Co Ltd | Light guide plate and backlight device |
-
2005
- 2005-11-17 KR KR1020077010876A patent/KR20070059213A/en not_active Application Discontinuation
- 2005-11-17 WO PCT/JP2005/021139 patent/WO2006054654A1/en active Application Filing
- 2005-11-18 TW TW094140576A patent/TW200622445A/en unknown
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1020125A (en) * | 1996-06-28 | 1998-01-23 | Nitto Denko Corp | Surface light source device and liquid crystal display device |
JP2003066235A (en) * | 2001-08-27 | 2003-03-05 | Sanyo Electric Co Ltd | Light transmission plate and surface light source device using the same |
JP2003098356A (en) * | 2001-09-20 | 2003-04-03 | Pioneer Electronic Corp | Light transmission plate |
JP2004111384A (en) * | 2002-08-30 | 2004-04-08 | Hitachi Chem Co Ltd | Light guide plate and backlight device |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1876388A1 (en) * | 2006-07-04 | 2008-01-09 | Samsung SDI Co., Ltd. | Light guide member and backlight unit including light guide member |
US7568827B2 (en) | 2006-07-04 | 2009-08-04 | Samsung Mobile Display Co., Ltd. | Light guide member and backlight unit including light guide member |
Also Published As
Publication number | Publication date |
---|---|
TW200622445A (en) | 2006-07-01 |
KR20070059213A (en) | 2007-06-11 |
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