WO2010095305A1 - 照明装置、面光源装置、および、液晶表示装置 - Google Patents
照明装置、面光源装置、および、液晶表示装置 Download PDFInfo
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- WO2010095305A1 WO2010095305A1 PCT/JP2009/066940 JP2009066940W WO2010095305A1 WO 2010095305 A1 WO2010095305 A1 WO 2010095305A1 JP 2009066940 W JP2009066940 W JP 2009066940W WO 2010095305 A1 WO2010095305 A1 WO 2010095305A1
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- light
- light guide
- light source
- reflection sheet
- liquid crystal
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- 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
- G02B6/0033—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
- G02B6/0075—Arrangements of multiple light guides
- G02B6/0078—Side-by-side arrangements, e.g. for large area displays
- G02B6/008—Side-by-side arrangements, e.g. for large area displays of the partially overlapping type
-
- 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
Definitions
- the present invention relates to an illumination device used as a backlight of a liquid crystal display device, a surface light source device, and a liquid crystal display device including the surface light source device.
- liquid crystal display devices which are rapidly spreading in place of cathode ray tubes (CRT), are widely used in liquid crystal televisions, monitors, mobile phones and the like, taking advantage of their energy-saving, thin, and lightweight features.
- improvement of an illuminating device (so-called backlight) disposed behind the liquid crystal display device can be mentioned.
- Backlights which are lighting devices, are mainly classified into side light types (also called edge light types) and direct types.
- the sidelight type has a configuration in which a light guide plate is provided behind the liquid crystal display panel and a light source is provided at an end of the light guide plate. Light emitted from the light source is reflected by the light guide plate and indirectly irradiates the liquid crystal display panel indirectly. With this structure, it is possible to realize a lighting device that is low in luminance but thin. For this reason, sidelight type lighting devices are mainly used in small and medium liquid crystal displays such as mobile phones and notebook computers.
- the direct type lighting device arranges a plurality of light sources behind the liquid crystal display panel and directly irradiates the liquid crystal display panel. Therefore, it is easy to obtain high brightness even on a large screen, and it is mainly used in large liquid crystal displays of 20 inches or more.
- the current direct type illumination device has a thickness of about 20 mm to 40 mm, which is an obstacle to further thinning the display.
- Aiming for further thinning with large liquid crystal displays can be solved by reducing the distance between the light source and the liquid crystal display panel, but in that case, if the number of light sources is not increased, the brightness uniformity of the lighting device can be obtained. Can not. On the other hand, increasing the number of light sources increases the cost. Therefore, it is desired to develop a lighting device that is thin and excellent in luminance uniformity without increasing the number of light sources.
- Patent Document 1 As shown in FIG. 9, a plurality of elongated rod-like fluorescent lamps L1, L2, and L3 are used as a primary light source, and a plurality of light guide blocks BL1, BL2, and BL3 are partially provided. A light guide block arranged so as to overlap with a so-called tandem is disclosed.
- the light guide block BL1 is supplied with primary light from the primary light source L1, and the other primary light sources L2 and L3 are disposed in recesses formed near the front ends of the light guide blocks BL1 and BL2. In this configuration, primary light is supplied to the blocks BL2 and BL3.
- the overlapping portions of the adjacent light guide blocks are formed by tongue-shaped overlapping portions 117a, 117b, 127a, 127b and strip-shaped overlapping portions 117c, 127c.
- the use of the superposition structure can prevent insufficient luminance that tends to appear in the vicinity of the electrodes because the electrodes exist at both ends of the primary light sources L2 and L3. Yes.
- FIG. 10 (a) is a side view of a conventional tandem illumination device 201
- FIG. 10 (b) is a front view of the conventional tandem illumination device 201 as viewed from the exit surface side.
- a plurality of LED light sources 203 that are point light sources are used as primary light sources
- the illumination device 201 includes: A plurality of light guides 202 each having a light emitting part 202b having an emission surface 202c and a light guiding part 202a for guiding light from the LED light source 203 to the light emitting part 202b are provided.
- the plurality of light guides 202 are arranged such that the light emitting part 202b of the other light guide 202 adjacent to the one light guide 202 rides on the light guide 202a of one light guide 202. ing.
- the light guide 202 reflects light leaking from the upper and lower surfaces of the light guide 202a of the light guide 202 or the lower surface of the light emitting part 202b, and returns the light to the light guide 202 again.
- a reflection sheet 204 that improves the light utilization efficiency is provided.
- a part of the reflective sheet 204 rides on the upper surface of the light guide portion 202 a of one light guide 202 and the one light guide 202.
- the other light guide 202 is disposed so as to be sandwiched between the lower surface of the light emitting portion 202b of the other light guide 202, and one end of the reflection sheet 204 is one end of the light guide 202 on the light source 203 side.
- a lighting device for a large liquid crystal display can be thinned.
- Japanese Patent Publication Japanese Patent Laid-Open No. 11-288611 (published Oct. 19, 1999)”
- the local dimming technique is a technique in which each of the point light sources is independently controlled and the luminance of the light emitting surface of the lighting apparatus is partially controlled in an illumination apparatus having a plurality of point light sources such as LED light sources. is there.
- a point light source such as an LED light source
- it has the advantage that the local dimming technique can be easily realized, but more uniform light can be emitted from the entire light exit surface of the light guide.
- it is necessary to provide a light guide unit for guiding the light emitted from the LED light source to the light emitting unit while sufficiently diffusing the light emitted from the LED light source in the light guide, in addition to the light emitting unit having the emission surface.
- the light guide section needs to guide the light emitted from the LED light source to the light emitting section without loss. By eliminating the loss of light, a lighting device with high light utilization efficiency can be realized.
- the light guide unit in order to eliminate the loss of light, it is necessary that light incident on the light guide from the light source repeats total reflection in the light guide unit and is guided to the light emitting unit.
- FIG. 11 is a plan view showing a schematic configuration of the light guide 202 provided in the conventional tandem illumination device 201.
- the light that enters the light guide 202 from the air layer outside the light guide 202 provided with the LED light source 203 falls within the critical angle ⁇ according to Snell's law.
- the refractive index n2 of the material layer 206 is expressed by the following formula (1). n2 ⁇
- n1 1.49. Therefore, in order to satisfy the total reflection condition, the material layer 206 satisfies n2 ⁇ 1.10. I should be satisfied.
- n1 1.59. Therefore, in order to satisfy the total reflection condition, the material layer 206 only needs to satisfy n2 ⁇ 1.236.
- the light guide 202 is configured so that the light guide 202 satisfies the total reflection condition using the example in which the material layer 206 is formed on the left and right surfaces of the light guide 202.
- the refractive index n2 of the material layer 206 has been described, since the light emitted from the LED light source 203 spreads radially, the above-described material layer 206 is formed even when the material layer 206 is formed on the upper and lower surfaces of the light guide 202.
- the refractive index n2 of the material layer 206 for the light guide 202 to satisfy the total reflection condition is the same.
- the reflection sheet 204 is provided so as to be in close contact with or in contact with the upper and lower surfaces of the light guide 202 a of the light guide 202. Yes. That is, the material layer 206 is a reflective sheet 204.
- the reflection sheet 204 made of a plastic film such as a PET film having a refractive index substantially equal to the refractive index of the light guide 202 is provided at the boundary between the upper and lower surfaces of the light guide 202 a of the light guide 202. ing.
- the light guide 202 and the reflection sheet 204 have almost no difference in refractive index. Therefore, the light incident on the light guide 202 is a boundary between the upper and lower surfaces of the light guide 202 a and the reflection sheet 204. The light is not totally reflected on the surface, but is guided to the light emitting unit 202b by reflection by the reflection sheet 204.
- the present invention has been made in view of the above problems, and an object thereof is to provide a lighting device that is thin, has high light utilization efficiency, and can realize local dimming.
- the lighting device of the present invention includes a plurality of combinations of a point light source and a light guide that diffuses light from the light source to emit light
- the light guide includes: Each has a light emitting part having an emission surface and a light guide part for guiding the light from the light source to the light emitting part, and the light guide part of one light guide member has the other adjacent to the one light guide member.
- a reflection sheet is provided on the facing surface facing the light exit surface of the light guide so as to cover the facing surface, At least one of the reflection sheet and the light guide part of the light guide is provided with a protrusion so that a gap is formed in at least a part between the light guide part and the reflection sheet.
- PC polycarbonate
- PMMA polymethyl methacrylate
- At least one of the reflection sheet and the light guide portion of the light guide has a protruding portion so that a gap is formed in at least a part of a portion where the light guide portion and the reflection sheet are in contact with each other. Is provided.
- the protrusion can provide a gap in at least a portion between the light guide and the reflective sheet that are provided in contact with each other.
- the air gap is an air layer having a refractive index of 1
- the refractive index of at least a part between the light guide unit and the reflection sheet is higher than the refractive index of the light guide.
- the light guide section in the area where the gap is provided (area where the air layer is in contact), the light guide is relative to the normal line of the upper and lower surfaces of the light guide section. Since all light incident at an incident angle exceeding the total reflection critical angle determined by the material constituting the body is totally reflected, it is possible to improve the light utilization efficiency.
- the illuminating device of the present invention includes, in the reflection sheet, a light guide portion of one light guide, and a light emitting portion of the other light guide adjacent to the light guide disposed so as to run on the light guide. It is preferable that the region sandwiched between is at least a double-sided reflection sheet.
- the total reflection critical angle is less than the normal to the upper surface of the light guide unit. Light incident at an incident angle and leaked without being reflected on the upper surface of the light guide unit can be reflected by the double-sided reflection sheet and returned to the light guide unit. Therefore, the light utilization efficiency can be further improved.
- the total reflection critical angle is determined by the material constituting the light guide.
- the protrusion is provided so that a contact area with the light guide is less than a contact area with the reflection sheet.
- the said projection part is formed from the same material as the said light guide or the said reflection sheet with a comparatively high refractive index, by making a projection part into the above shapes, The light leaking from the light guide can be suppressed. Therefore, an illumination device with high light use efficiency can be realized.
- the protrusion is formed of a light transmissive material.
- the protrusion is made of a light-transmitting material, light loss due to light absorption or the like can be suppressed in the protrusion. Therefore, an illumination device with high light use efficiency can be realized.
- the protrusion is provided on the reflection sheet.
- the said projection part is provided in the said reflection sheet side, the light which leaks from the said light guide part can be suppressed, and an illuminating device with high utilization efficiency of light is implement
- the protrusion is provided so as to be located in a region where the light of the point light source of the light guide is not irradiated.
- the phrase “the protrusion is provided so as to be located in a region where the light of the point light source of the light guide part is not irradiated” means that the protrusion is on the light guide part side or the reflection side. Even if it is provided on either side of the sheet, when a plurality of light guides are arranged in tandem, the protrusions are in areas where light from the point light source in the light guide part of the light guides is not irradiated. Means to be located.
- the projection is irradiated with the light from the point light source of the light guide unit, regardless of whether the projection is provided on the light guide unit side or the reflection sheet side. Since the light is leaked from the light guide portion due to the influence of the protrusions, an illumination device with high light use efficiency can be realized.
- the reflection sheet is bonded to the light guide by an adhesive portion.
- a surface light source device of the present invention is characterized by including the illumination device and an optical member provided on a light emitting surface of the illumination device.
- the optical member is, for example, a diffusing plate having a thickness of about 2 to 3 mm disposed at a location about several mm away from the lighting device.
- the thickness of the optical member and the distance from the illumination device are not limited to the above.
- Multiple function optical sheets may be laminated.
- the thicknesses and configurations described above are illustrative and are not limited thereto.
- the liquid crystal display device of the present invention is characterized by including the surface light source device as a backlight in order to solve the above problems.
- the surface light source device is provided as a backlight, it is possible to realize a thin liquid crystal display device with good display quality.
- the illuminating device of the present invention includes at least one of the reflection sheet provided so as to cover the facing surface facing the emission surface of the light guide and the light guide portion of the light guide.
- the protrusion is provided so that a gap is formed in at least a portion between the light guide and the reflection sheet.
- the surface light source device of the present invention is provided with an optical member on the light emitting surface of the illumination device.
- the liquid crystal display device of the present invention includes the surface light source device as a backlight as described above.
- the surface light source device as a backlight, it is possible to realize a thin liquid crystal display device with good display quality.
- FIG. 1 It is a side view of the illuminating device with which the liquid crystal display device of one embodiment of this invention was equipped. It is a perspective view of the illuminating device of FIG. It is a side view which shows schematic structure of the liquid crystal display device of one embodiment of this invention. It is the elements on larger scale of the illuminating device of FIG. It is a figure which shows another example which provides a projection part in a reflective sheet in the illuminating device with which the liquid crystal display device of one embodiment of this invention was equipped. It is a figure which shows an example of the reflective sheet which has a projection part in the illuminating device with which the liquid crystal display device of one embodiment of this invention was equipped, (a) is an example of the reflective sheet provided in the lower surface of a light guide part.
- (B) shows an example of the reflective sheet provided on the lower surface of the light emitting part
- (c) shows an example of the reflective sheet provided on the lower surface of the light guide.
- the projection part was provided in the light guide part of the light guide.
- the illuminating device is a illuminating device that is thin, has high light utilization efficiency, and can realize local dimming.
- the surface light source device is a surface light source device that is thin, has high light utilization efficiency, can realize local dimming, and has improved luminance uniformity.
- the liquid crystal display device is a thin liquid crystal display device having good display quality by including the surface light source device as a backlight.
- FIG. 3 is a side view showing a schematic configuration of the liquid crystal display device 51 according to the embodiment of the present invention.
- the liquid crystal display device 51 includes a liquid crystal display panel 21 and a surface light source device 41 including a lighting device 31 as a backlight that emits light toward the liquid crystal display panel 21.
- the lighting device 31 includes a plurality of combinations of the light guide 1 and the point light source 2.
- the light guide 1 includes a light guide portion 1a and a light emitting portion 1b.
- the light guide portion 1a guides light from the point light source 2 to the light emitting portion 1b, and the light emitting portion 1b faces the light exiting surface 1c. Make it emit light.
- FIG. 2 is a perspective view of the lighting device 31.
- the lighting device 31 has a plurality of the light guides 1 arranged adjacent to each other, and a plurality of light emitting surfaces 1 c can form a large light emitting surface 7 that is flush with the surface.
- Each light guide 1 has a shape such that the light emitting part 1b of the other light guide 1 adjacent to the one light guide 1 can be placed on the light guide 1a of one light guide 1. Is configured.
- a reflection sheet 3 described later in detail is provided as shown in FIG.
- the projection part 4 is provided in the said reflection sheet 3 so that a space
- the surface light source device 41 (backlight) further includes a substrate 5 that supports the illumination device 31 and an optical member 6 disposed behind the liquid crystal display panel 21 (on the side opposite to the display surface). Yes.
- the back surface of the optical member 6 is an irradiation target surface of light emitted from the emission surface 1c.
- FIG. 1 is a side view of a lighting device 31 provided in a liquid crystal display device 51 according to an embodiment of the present invention.
- the protrusion 4 is formed on the reflective sheet 3 so that a gap is formed in at least a part of a portion where the light guide unit 1 a and the reflective sheet 3 are in contact with each other. Is provided.
- the protrusion 4 can provide a gap in at least a portion between the light guide 1a and the reflection sheet 3 provided so as to be in contact with each other.
- the air gap is an air layer having a refractive index of 1, according to the above configuration, the refractive index of the light guide 1 is at least partially between the light guide portion 1a and the reflection sheet 3.
- An air layer having a large refractive index can be provided.
- the normal line of the upper and lower surfaces of the light guide portion 1a is Since all the light incident at an incident angle exceeding the total reflection critical angle determined by the material constituting the light guide 1 is totally reflected, the light utilization efficiency can be improved.
- the illumination device 31 that is thin, has high light utilization efficiency, and can realize local dimming.
- the projection 4 is provided on the reflection sheet 3 in order to realize a lighting device with high light utilization efficiency.
- the projection 4 is at least the reflection sheet 3. And any one of the light guide part 1a of the light guide 1 may be provided.
- FIG. 4 is a partially enlarged view of the lighting device 31 shown in FIG.
- the protrusion 4 is provided such that the contact area with the light guide 1 a is less than the contact area with the reflection sheet 3. It is preferable.
- the contact area between the reflection sheet 3 and the protrusions 4 is the formation area of each protrusion 4 on the surface of the reflection sheet 3. It means the area.
- the protrusion 4 has, for example, a fine concavo-convex shape, a protrusion, or a columnar shape at a portion that touches the light guide 1 a of the light guide 1.
- the protrusion 4 has a minimum size that can provide a gap in at least a part of a portion where the light guide portion 1a and the reflection sheet 3 are in contact with each other. This is preferable for realizing a lighting device with high utilization efficiency.
- the shape of the protrusion 4 is a conical shape that reduces the contact area with the light guide portion 1a.
- the present invention is not limited to this. Any shape may be used as long as the contact area with the light guide portion 1a is small.
- the reflection sheet 3 is integrally molded by embossing, and the projections 4 are provided on the reflection sheet 3.
- the present invention is not limited to this.
- a method of forming the sheet at the same time as the formation of the sheet by injection molding, molding by a mold, embossing or the like can be used. That is, a known method can be appropriately used as long as the method can provide the protrusion 4 on the reflective sheet 3.
- the protrusion 4 is provided in a region where the light from the point light source 2 of the light guide 1a is not transmitted.
- the light guide unit 202a is not irradiated with light, and there is a dark and shadow region R1. That is, the light from the light source 203 is not irradiated to the wide-angle region R1 than the light irradiated with the critical angle ⁇ from the right end or the left end of the light source 203.
- the light guide unit 1a is not irradiated with light corresponding to the region R1 in FIG. To do.
- this projection part 4 is the said dotted
- the protrusion 4 is preferably formed of a light transmissive material.
- the protrusion 4 may be formed of a light transmissive material in order to prevent light from being blocked. Thereby, the amount of light blocked by the protrusion 4 can be reduced.
- Examples of the light transmissive material include, but are not limited to, a transparent resin such as acrylic or polycarbonate.
- the protrusion 4 is made of a light-transmitting material, light loss due to light absorption or the like can be suppressed in the protrusion 4. Therefore, the lighting device 31 with high light use efficiency can be realized.
- the reflective sheet 3 is preferably bonded to the light guide 1 by an adhesive portion 8.
- the position shift of the said reflection sheet 3 can be suppressed, and the said light guide 1 is combined.
- the workability at the time can be improved.
- the adhesive portion 8 is, for example, a double-sided tape or an adhesive paste, and the adhesive portion 8 is preferably a transparent material in order to realize the lighting device 31 with high light utilization efficiency.
- FIG. 5 is a view showing still another example in which the projection 4 is provided on the reflection sheet 3.
- the reflection having the protrusions 4 on both the upper and lower surfaces of the light guide 1a in order to realize the illumination device 31 with high light utilization efficiency, the reflection having the protrusions 4 on both the upper and lower surfaces of the light guide 1a.
- the configuration in which the sheet 3 is provided is used, as illustrated in FIG. 5, the configuration in which the reflective sheet 3 having the protrusions 4 is provided only on the upper surface of the light guide portion 1 a is used. You can also Moreover, although not shown in figure, the structure by which the reflective sheet 3 which has the said projection part 4 is provided only in the lower surface of the said light guide part 1a can also be used.
- the reflection sheet 3 described above is provided on the opposite side of the light guide body 1 from the surface having the emission surface 1 c so as to individually cover the opposite surface. At the same time, the light that passes through the opposite surface of each of the light guides 1 is reflected and returned to the light guide 1, thereby improving the light use efficiency of each light guide 1. ing. More specifically, the reflection sheet 3 is made of a material constituting the light guide 1 with respect to the normal of the surface opposite to the surface having the exit surface 1c of each light guide 1. By making the incident light below the determined total reflection critical angle, the light that passes through the light guide 1 is reflected and returned to the light guide 1.
- the region sandwiched between the light emitter 1b of the light body 1 is preferably at least a double-sided reflection sheet.
- the total reflection critical angle with respect to the normal line of the upper surface of the said light guide part 1a The incident light with an incident angle lower than the above and reflected from the upper surface of the light guide unit 1a without being reflected can be reflected by the double-sided reflection sheet and returned to the light guide unit 1a. Therefore, the light utilization efficiency can be further improved.
- the reflection sheet 3 either a regular reflection sheet on which a highly reflective substance such as silver or aluminum is vapor-deposited or a white reflection sheet having diffuse reflection is used, or a reflection obtained by superimposing the two reflection sheets. Sheets can be used.
- the PET-based white reflective sheet can be broadly classified according to its configuration.
- a type in which white inorganic particles are added to PET a type in which a resin incompatible with PET (such as an olefin-based resin) is added to PET, carbon dioxide gas in a PET sheet, etc.
- a resin incompatible with PET such as an olefin-based resin
- carbon dioxide gas in a PET sheet etc.
- types that are impregnated and foamed There are types that are impregnated and foamed, and any type may be used.
- a diffuse reflection layer can be easily formed. Diffuse reflection due to fine unevenness can more effectively suppress the occurrence of luminance unevenness on the exit surface 1c.
- Examples of the method for providing irregularities on the specular reflection sheet include a method of forming the sheet simultaneously with the formation of the sheet by injection molding, molding with a mold, embossing, or the like.
- other examples include a method of subjecting the surface of the regular reflection sheet to prism processing, dot processing, or rough surface treatment with a laser or the like.
- the double-sided reflective sheet 3 may be used as it is, or the single-sided reflective sheets are bonded together using a commercially available adhesive (glue) or the like. Can also be used.
- a PET-based white reflective sheet is used as the reflective sheet 3, and a double-sided reflective sheet is used.
- FIG. 6 is a view showing an example of the reflection sheet 3 having the protrusions 4.
- FIG. 6 shows an example of the reflective sheet provided on the lower surface of the light guide portion 1a.
- FIG. 6 shows an example of the reflection sheet provided on the lower surface of the light emitting unit 1b.
- FIG. 6 shows an example of the reflective sheet provided on the lower surface of the light guide 1.
- each light guide 1 By using a reflection sheet as illustrated in FIG. 6C, it is only necessary to provide each light guide 1 with one reflection sheet, so that workability can be improved. On the other hand, when a reflective sheet as shown in FIGS. 6A and 6B is used, it is necessary to provide each light guide 1 with two reflective sheets.
- the substrate 5 is used for disposing the point light source 2 and is preferably white in order to improve luminance.
- a driver for controlling lighting of each LED constituting the point light source 2 is not shown on the back side (surface opposite to the surface on which the point light source 2 is mounted) side of the substrate 5.
- the driver is mounted on the same substrate 5 together with the LEDs.
- the optical member 6 is composed of at least a diffusion plate that diffuses received light to improve the uniformity of brightness, and is preferably configured by combining a composite functional optical member with the diffusion plate.
- the composite functional optical member has a plurality of optical functions selected from various optical functions including diffusion, refraction, condensing, and polarization.
- a diffuser plate having a thickness of about 2 to 3 mm arranged at a location separated from the illumination device 31 by about several mm can be adopted.
- the thickness of the diffusion plate and the distance from the illumination device 31 are not limited to the above.
- the diffuser plate is disposed to face the light emitting surface at a predetermined distance from the light emitting surface so as to cover the entire light emitting surface formed by connecting the plurality of light emitting surfaces 1c.
- the diffusion plate diffuses light emitted from the light emitting surface.
- the surface light source device 41 for example, a diffusion sheet of about several hundred ⁇ m, a prism sheet, or a polarizing reflection sheet is provided on the upper surface of the diffusion plate so as to ensure even better luminance and luminance uniformity.
- a multi-function optical member such as may be laminated. The thicknesses and configurations described above are illustrative and are not limited thereto.
- the composite functional optical member is constituted by a plurality of stacked sheets, and uniformizes and collects the light emitted from the emission surface 1c of the light guide 1 and irradiates the liquid crystal display panel 21. .
- the composite functional optical member includes a diffusion sheet that collects and scatters light, a lens sheet that collects light and improves the luminance in the front direction (the direction of the liquid crystal display panel 21), and one of the lights.
- a polarization reflection sheet that improves the luminance of the liquid crystal display device 51 by reflecting one of the polarization components and transmitting the other polarization component can be applied. These are preferably used in appropriate combination depending on the price and performance of the liquid crystal display device 51.
- the optical member 6 is provided on the light emitting surface of the illumination device 31 in the surface light source device 41 provided in the liquid crystal display device 51 of the present embodiment.
- the surface light source device 41 that is thin, has high light utilization efficiency, can realize local dimming, and has improved luminance uniformity.
- the liquid crystal display device 51 of the present embodiment includes the surface light source device 41 as a backlight.
- the surface light source device 41 is provided as a backlight, it is possible to realize a thin liquid crystal display device 51 with good display quality.
- the light guide 1 is configured so that the light incident from the incident surface 1 d facing the point light source 2 is efficiently emitted from the emission surface 1 c. It is necessary to minimize the loss of light in the light guide portion 1a.
- the incident light is guided in the light guide portion 1a while satisfying the total reflection condition, thereby maintaining the light quantity. It is the structure which can do.
- the exit surface 1c is provided substantially in parallel with the optical member 6 described above, so that the illumination device 31 of the present invention is combined with the optical member 6 to obtain a uniform surface.
- the distance from the emitting surface 1c to the optical member 6 can be easily made constant, so that optical design for uniform surface light emission is facilitated. Benefits can be created.
- the exit surface 1 c It is not parallel to the surface opposite to the surface 1c.
- the shape of the light emitting portion 1b is formed so as to become narrower as the distance from the point light source 2 increases, that is, the surface on the opposite side asymptotically approaches the emission surface 1c.
- the light guided through the light guide 1 gradually loses its total reflection condition as it goes away from the point light source 2, and exits from the exit surface 1c. Will be.
- the surface (light exit surface 1c) or the back surface of the light emitting unit 1b is subjected to processing (fine unevenness processing) or processing for emitting the guided light.
- processing method and processing method include prism processing, texture processing, and printing processing, but are not particularly limited, and known methods can be used as appropriate.
- the light guide 1 may be formed of a transparent resin such as polycarbonate (PC) or polymethyl methacrylate (PMMA), but is not limited thereto, and is formed of a material generally used as a light guide. can do.
- the light guide 1 can be formed by, for example, injection molding, extrusion molding, hot press molding, cutting, or the like. However, it is not limited to these methods, and any method may be used as long as it is a processing method that exhibits the same characteristics.
- the point light source 2 is arranged along the end of the light guide 1a of the light guide 1 as shown in FIG.
- a light emitting diode LED
- the point light source 2 a light source composed of a plurality of types of light emitting diodes having different emission colors can be used. Specifically, it is composed of an LED group in which a plurality of light emitting diodes of three colors of red (R), green (G), and blue (B) are arranged. By configuring the point light source 2 by combining these three color light emitting diodes, white light can be irradiated on the emission surface 1c.
- the combination of the colors of the light emitting diodes can be determined as appropriate based on the color development characteristics of the LEDs of the respective colors and the color development characteristics of the surface light source device 41 desired according to the purpose of use of the liquid crystal display device 51. .
- a side light emitting type LED in which LED chips of respective colors are molded in one package may be used. Thereby, it becomes possible to obtain the illuminating device 31 with a wide color reproduction range.
- a transmissive liquid crystal display panel that performs display by transmitting light from the surface light source device 41 (backlight) is used as the liquid crystal display panel 21.
- the structure of the liquid crystal display panel 21 is not specifically limited, A well-known liquid crystal display panel can be applied suitably.
- the liquid crystal display panel 21 includes, for example, an active matrix substrate on which a plurality of TFTs (thin film transistors) are formed, and a color filter substrate facing the active matrix substrate, and a liquid crystal layer is sealed between these substrates. It has the structure enclosed with the material.
- the light quantity of each of the plurality of point light sources 2 is independently adjusted (independent drive). Since the amount of light emitted from each of the exit surfaces 1c can be adjusted independently and the illumination brightness can be adjusted for each light emitting surface of a predetermined size, local dimming driving can be performed.
- the manufacturing method of the liquid crystal display device having the local dimming driving function can be performed in accordance with a conventionally known manufacturing method of a liquid crystal display device that can perform local dimming driving, and thus the description thereof is omitted.
- Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIGS.
- This embodiment shows a modification in the case where the protrusion 4 in Embodiment 1 is provided in the light guide 1a of the light guide 1.
- FIG. 7 is a diagram illustrating an example in which the protrusion 4 is provided on the light guide 1a of the light guide 1 in the illumination device 31a according to another embodiment of the present invention.
- FIG. 8 is a diagram showing still another example in which the protrusion 4 is provided on the light guide 1a of the light guide 1 in the illumination device 31a according to another embodiment of the present invention.
- the light guide unit 1a and the light guide unit 1a may be provided on both the upper and lower surfaces of the light guide unit 1a.
- the structure having the protrusion 4 is used so that a gap is formed in at least a part of the portion in contact with the reflection sheet 3.
- the structure is provided only on the upper surface of the light guide 1 a.
- a configuration having the protrusions 4 can also be used.
- a configuration having the protrusions 4 only on the lower surface of the light guide portion 1a can be used.
- integral molding such as thermoforming or injection molding, molding by shaving, addition of a shape using a UV curable resin, etc.
- a method can be used, it is not limited to these, and a well-known method can be used suitably.
- a columnar shape is used as the protrusion 4 such that the contact area with the light guide 1a is less than the contact area with the reflection sheet 3. It is not limited to.
- the density of the protrusions 4 provided on the light guide portion 1a is too high, the area where the light is totally reflected is reduced, and the light use efficiency is lowered.
- the protrusion 4 is preferably provided at the end of the light guide 1a.
- the illumination device 31a that is thin, has high light utilization efficiency, and can realize local dimming.
- the present invention can be applied to a lighting device used as a backlight of a liquid crystal display device, a surface light source device including the lighting device, and a liquid crystal display device including the surface light source device.
Abstract
Description
n2<|√{(n1)2-1}|…(1)
を満足すればよい。
図3は、本発明の一実施の形態の液晶表示装置51の概略構成を示す側面図である。
以下、図1および図4~6を参照して、上記照明装置31に備えられた上記反射シート3に設けられた突起部4について説明する。
つぎに、図7~8に基づいて、本発明の第2の実施形態について説明する。本実施形態は、実施の形態1における突起部4が、導光体1の導光部1aに設けられてある場合の変形例を示すものである。
1a 導光部
1b 発光部
1c 出射面
1d 入射面
2 点状光源(LED光源)
3 反射シート
4 突起部
5 基板
6 光学部材
7 発光面
8 接着部
21 液晶表示パネル
31、31a 照明装置
41 面光源装置
51 液晶表示装置
R1 光が照射されない領域
Claims (9)
- 点状光源と、該光源からの光を拡散させて面発光させる導光体との組み合わせを複数個備え、上記導光体は、それぞれ、出射面を有する発光部と、該発光部へ上記光源からの光を導く導光部とを有し、一方の導光体の導光部に、該一方の導光体に隣り合う他方の導光体の発光部が乗り上げるように配置されてなる照明装置において、
上記導光体の出射面と対向する対向面には、該対向面を覆うように反射シートが設けられており、
上記反射シートと上記導光体の導光部との少なくとも一方には、
上記導光部と上記反射シートとの間の少なくとも一部分に空隙ができるように、突起部が設けられていることを特徴とする照明装置。 - 上記反射シートにおいて、
一方の導光体の導光部と、
上記導光部に乗り上げるように配置される上記導光体に隣り合う他方の導光体の発光部とに挟まれる領域は、
少なくとも、両面反射シートであることを特徴とする請求項1に記載の照明装置。 - 上記突起部は、上記導光部との接触面積が、上記反射シートとの接触面積未満となるように設けられていることを特徴とする請求項1または2に記載の照明装置。
- 上記突起部は、光透過性を有する材料で形成されていることを特徴とする請求項1から3の何れか1項に記載の照明装置。
- 上記突起部は、上記反射シートに設けられていることを特徴とする請求項1から4の何れか1項に記載の照明装置。
- 上記突起部は、上記導光部の上記点状光源の光が照射されない領域に位置するように設けられていることを特徴とする請求項1から5の何れか1項に記載の照明装置。
- 上記反射シートは、接着部により、上記導光体に接着されていることを特徴とする請求項1から6の何れか1項に記載の照明装置。
- 請求項1から7の何れか1項に記載の照明装置と、
上記照明装置の発光面上に設けられた光学部材とを備えていることを特徴とする面光源装置。 - 請求項8に記載の面光源装置をバックライトとして備えていることを特徴とする液晶表示装置。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/146,204 US20110292684A1 (en) | 2009-02-23 | 2009-09-29 | Illumination device, surface illuminant device, and liquid crystal display device |
CN2009801560506A CN102301177A (zh) | 2009-02-23 | 2009-09-29 | 照明装置、面光源装置和液晶显示装置 |
RU2011131380/07A RU2011131380A (ru) | 2009-02-23 | 2009-09-29 | Осветительное устройство, поверхностное осветительное устройство и жидкокристаллический дисплей |
JP2011500457A JPWO2010095305A1 (ja) | 2009-02-23 | 2009-09-29 | 照明装置、面光源装置、および、液晶表示装置 |
EP09840408A EP2383507A1 (en) | 2009-02-23 | 2009-09-29 | Illuminating device, surface light source, and liquid crystal display device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2009039460 | 2009-02-23 | ||
JP2009-039460 | 2009-02-23 |
Publications (1)
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WO2010095305A1 true WO2010095305A1 (ja) | 2010-08-26 |
Family
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PCT/JP2009/066940 WO2010095305A1 (ja) | 2009-02-23 | 2009-09-29 | 照明装置、面光源装置、および、液晶表示装置 |
Country Status (7)
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US (1) | US20110292684A1 (ja) |
EP (1) | EP2383507A1 (ja) |
JP (1) | JPWO2010095305A1 (ja) |
KR (1) | KR20110114641A (ja) |
CN (1) | CN102301177A (ja) |
RU (1) | RU2011131380A (ja) |
WO (1) | WO2010095305A1 (ja) |
Cited By (4)
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WO2012053379A1 (ja) * | 2010-10-18 | 2012-04-26 | シャープ株式会社 | 太陽電池モジュールおよび太陽光発電装置 |
JP2013149559A (ja) * | 2012-01-23 | 2013-08-01 | Sharp Corp | 照明装置、表示装置、及びテレビ受信装置 |
WO2014196266A1 (ja) * | 2013-06-07 | 2014-12-11 | 古河電気工業株式会社 | 反射フレームおよびバックライトユニット |
KR101592071B1 (ko) | 2012-12-19 | 2016-02-05 | 독터. 인제니어. 하.체. 에프. 포르쉐 악티엔게젤샤프트 | 자동차 조명기구 및 자동차 조명기구를 갖는 자동차 |
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JP2012032763A (ja) * | 2010-06-28 | 2012-02-16 | Hitachi Consumer Electronics Co Ltd | 液晶表示装置、バックライトおよびled |
FR3042845B1 (fr) * | 2015-10-23 | 2019-11-29 | Valeo Vision | Dispositif lumineux a guides optiques |
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- 2009-09-29 US US13/146,204 patent/US20110292684A1/en not_active Abandoned
- 2009-09-29 CN CN2009801560506A patent/CN102301177A/zh active Pending
- 2009-09-29 RU RU2011131380/07A patent/RU2011131380A/ru unknown
- 2009-09-29 KR KR1020117018632A patent/KR20110114641A/ko not_active Application Discontinuation
- 2009-09-29 WO PCT/JP2009/066940 patent/WO2010095305A1/ja active Application Filing
- 2009-09-29 EP EP09840408A patent/EP2383507A1/en not_active Withdrawn
- 2009-09-29 JP JP2011500457A patent/JPWO2010095305A1/ja active Pending
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KR101592071B1 (ko) | 2012-12-19 | 2016-02-05 | 독터. 인제니어. 하.체. 에프. 포르쉐 악티엔게젤샤프트 | 자동차 조명기구 및 자동차 조명기구를 갖는 자동차 |
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Also Published As
Publication number | Publication date |
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KR20110114641A (ko) | 2011-10-19 |
US20110292684A1 (en) | 2011-12-01 |
CN102301177A (zh) | 2011-12-28 |
JPWO2010095305A1 (ja) | 2012-08-16 |
EP2383507A1 (en) | 2011-11-02 |
RU2011131380A (ru) | 2013-03-27 |
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