WO2022201378A1 - Dispositif de source de lumière plane et dispositif d'affichage - Google Patents

Dispositif de source de lumière plane et dispositif d'affichage Download PDF

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Publication number
WO2022201378A1
WO2022201378A1 PCT/JP2021/012340 JP2021012340W WO2022201378A1 WO 2022201378 A1 WO2022201378 A1 WO 2022201378A1 JP 2021012340 W JP2021012340 W JP 2021012340W WO 2022201378 A1 WO2022201378 A1 WO 2022201378A1
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Prior art keywords
light
light source
source device
guide plate
light guide
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PCT/JP2021/012340
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English (en)
Japanese (ja)
Inventor
俊輔 曽山
栄二 新倉
満 坂井
幹夫 荒木
Original Assignee
三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2021/012340 priority Critical patent/WO2022201378A1/fr
Priority to JP2023508274A priority patent/JP7341371B2/ja
Publication of WO2022201378A1 publication Critical patent/WO2022201378A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction

Definitions

  • the present disclosure relates to a planar light source device and a display device including the planar light source device.
  • a display device includes a planar light source device that emits light and a display panel that displays an image by partially shielding or transmitting light from the planar light source device.
  • a planar light source device that emits light
  • the planar light source device emits the same light as when displaying a bright image.
  • a technique called local dimming has been put into practical use, in which the light emitting area is divided and the brightness of the planar light source device is partially adjusted according to the brightness of the image displayed in each light emitting area after the division. ing. According to local dimming, it is possible to suppress the emission of light from the planar light source device more than necessary. Therefore, it is possible to output a high-contrast image while reducing the power consumption of the display device.
  • the display device of Patent Document 1 includes a plurality of light sources that can be driven independently of each other, a light guide plate that emits light incident from the plurality of light sources from a specific emission surface, and partition walls that divide the light guide plate into a plurality of cells. It is disclosed to comprise a Moreover, the partition has a notch partially, and the light guide plate is connected between adjacent cells through the notch of the partition. That is, the light guide plate is not completely separated between cells, and the light guide plate is partially connected between adjacent cells. By providing such partition walls, it is possible to locally adjust the brightness of light emitted from the light guide plate, and part of the light emitted from the light source of each cell enters the adjacent cell through the cutout. be. It is described that this eliminates the need to turn on the light source of the low-brightness cell when, for example, a cell requiring high-brightness light emission and a cell requiring low-brightness light emission are adjacent to each other. ing.
  • Local dimming is a technique that partially adjusts the brightness of the planar light source device according to the brightness of the image displayed in each light emitting area after division as described above. Therefore, it is important to suppress leakage light emitted from each divided light emitting region to other adjacent divided light emitting regions.
  • part of the light emitted from the light source of each cell enters the adjacent cell through the notch. With such a configuration, there is a risk that leakage light to adjacent cells will increase and the effect of local dimming will be reduced.
  • the present disclosure has been made to solve the above problems, and aims to provide a planar light source device and a display device capable of suppressing light leakage to adjacent divided light emitting regions. It is.
  • a planar light source device is a planar light source device capable of dividing a light emitting region, is arranged corresponding to each light emitting region after division, and emits light incident from the side surface from the upper surface.
  • a plurality of light guide plates installed on one light guide plate, a plurality of light sources each having a light emitting surface facing a side surface of the light guide plate and capable of being driven independently of each other;
  • Each of the light guide plates is provided with partition walls surrounding one light guide plate and one light source.
  • a display device includes the planar light source device described above and a display panel that displays an image on a screen by transmitting or blocking light from the planar light source device.
  • FIG. 1 is a front cross-sectional view showing a display device according to Embodiment 1;
  • FIG. Front cross-sectional view showing the planar light source device of Embodiment 1 1 is a cross-sectional plan view showing a planar light source device according to Embodiment 1;
  • FIG. 1 is a perspective view showing a light guide plate according to Embodiment 1;
  • FIG. 2 is a perspective view showing a partition according to Embodiment 1;
  • 1 is a front cross-sectional view showing a planar light source device according to Embodiment 1;
  • FIG. 1 is a front cross-sectional view showing a planar light source device according to Embodiment 1;
  • FIG. 2 is a perspective view showing a partition according to Embodiment 1; It is front sectional drawing which shows the planar light source device which concerns on a comparative example.
  • 3 is a cross-sectional plan view showing another example of the planar light source device of Embodiment 1;
  • FIG. 1 is a front cross-sectional view showing a planar light source device according to Embodiment 1;
  • FIG. 3 is a cross-sectional plan view showing another example of the planar light source device of Embodiment 1;
  • FIG. 10 is a front cross-sectional view showing a planar light source device according to Embodiment 2;
  • the x-axis represents the long-side direction of a light source substrate provided in a planar light source device to be described later
  • the y-axis represents the short-side direction of the light source substrate provided in the planar light source device
  • the z-axis represents the planar light source. It represents the direction orthogonal to the mounting surface of the light source substrate provided in the device.
  • the positive side of the z-axis is called the "front side”
  • the negative side of the z-axis is called the "back side”.
  • FIG. 1 is a front sectional view showing a display device 100 according to Embodiment 1.
  • the display device 100 includes a display panel 10, an optical sheet group 20, and a planar light source device 30.
  • the display device 100 includes a display panel 10, an optical sheet group 20, and a planar light source device 30.
  • the display panel 10 is a liquid crystal display panel.
  • the display panel 10 also includes a first substrate 11, a second substrate 12, and a liquid crystal layer sandwiched therebetween.
  • a color filter, a black matrix as a light shielding layer, a counter electrode, and the like are provided on an insulating substrate such as glass.
  • the second substrate 12 is provided with pixel electrodes, thin film transistors (TFTs) for supplying image signals to the pixel electrodes, and the like on an insulating substrate such as glass.
  • TFTs thin film transistors
  • a spacer for maintaining a gap therebetween a sealing material for bonding the first substrate 11 and the second substrate 12 together and sealing liquid crystal, and liquid crystal are provided.
  • An alignment film or the like for distributing light is provided.
  • polarizing plates are provided on the outer surface and the back surface of the display panel 10 .
  • a driving IC (not shown) is mounted on the outer peripheral portion of the second substrate 12 of the display panel 10 .
  • a circuit board for controlling the driving IC is connected to the display panel 10 .
  • the drive IC may be arranged on a tape-shaped wiring board connected to the outer periphery of the second substrate 12 .
  • a touch panel that detects a user's touch operation and a transparent protective member that protects the touch panel may be installed.
  • the display panel 10 transmits or shields light from a planar light source device 30, which will be described later, so that an image is displayed on the screen, which is the surface on the front side of the display panel 10.
  • the optical sheet group 20 is a plurality of sheet-like members provided between the display panel 10 and the planar light source device 30, as shown in FIG. or adjust the angle.
  • a specific configuration of the optical sheet group 20 is a diffuser plate 21, a diffuser sheet 22, two prism sheets 23, and a polarizing sheet 24 in order from the back side of the display device 100.
  • the diffuser plate 21 and the diffuser sheet 22 are members that diffuse the light emitted from the planar light source device 30 and suppress dark areas that may occur in the display panel 10 due to the partition walls 34 .
  • the prism sheet 23 is a member that narrows the viewing angle of the light transmitted through the diffuser plate 21 and the diffuser sheet 22 and improves the brightness in the positive z-axis direction.
  • the two prism sheets 23 are arranged so that the prism directions are orthogonal.
  • the polarizing sheet 24 is a member that improves the light utilization efficiency by reflecting and reusing the s-wave that does not pass through the display panel 10 out of the light that has passed through the prism sheet 23 .
  • the planar light source device 30 is arranged on the back side of the optical sheet group 20 and emits light to the display panel 10 via the optical sheet group 20 .
  • the planar light source device 30 of Embodiment 1 includes a light source substrate 31, a plurality of light sources 32, a plurality of light guide plates 33, partition walls 34, and a reflection sheet 35.
  • FIG. 1 the planar light source device 30 of Embodiment 1 includes a light source substrate 31, a plurality of light sources 32, a plurality of light guide plates 33, partition walls 34, and a reflection sheet 35.
  • the light source substrate 31 is a plate-like member located on the rearmost side of the planar light source device 30, and has, for example, a rectangular shape.
  • a plurality of light sources 32 are arranged on the mounting surface, which is the surface on the front side of the light source substrate 31 . Wiring is provided on the light source substrate 31 so that the light sources 32 can be driven independently in units of one or several.
  • FIG. 2 is a front sectional view showing the planar light source device 30 of Embodiment 1.
  • the light source 32 is a light emitting diode mounted on the light source substrate 31 and has a light emitting surface 321 that emits light.
  • One light source 32 is installed on one light guide plate 33 .
  • the light source 32 is installed so that the light-emitting surface 321 of the light source 32 faces the incident surface 331 of the light guide plate 33 .
  • the optical axis direction of the light source 32 is parallel to the light source substrate 31 , but it may be angled with respect to the light source substrate 31 .
  • the plurality of light sources 32 can be driven independently of each other as described above.
  • FIG. 3 is a plan sectional view showing the planar light source device 30 of the first embodiment
  • FIG. 4 is a perspective view showing the light guide plate 33 of the first embodiment.
  • the light guide plate 33 is arranged corresponding to each light emitting area after division in the planar light source device 30 capable of dividing the light emitting area.
  • the light guide plate 33 is a polygonal member made of acrylic resin or the like, and is arranged on the front side surface of the reflective sheet 35 to be described later. Further, by arranging the plurality of light guide plates 33 in a matrix as shown in FIG. 3 , it becomes easy to install the light guide plates 33 and the light sources 32 when manufacturing the planar light source device 30 .
  • the gaps between the light guide plates 33 should be made small in order to reduce uneven brightness on the screen.
  • the shape of the light guide plate 33 may be rectangular when viewed from the front side of the display device 100. FIG.
  • the light guide plate 33 has an incident surface 331 on its side surface for allowing the light emitted from the light source 32 to enter inside.
  • the light guide plate 33 may have a concave portion 334 for housing at least part of the light source 32 on the side surface.
  • the concave portion 334 is a broken line portion shown in FIG. 4 and is a concave portion formed in a part of the side surface of the light guide plate 33 .
  • the incident surface 331 may be formed in the concave portion 334 .
  • FIG. 4 shows an example in which a concave portion 334 having an incident surface 331 is formed at a corner portion of the light guide plate 33 .
  • the concave portion 334 may be omitted, and the incident surface 331 may be formed on the side surface of the light guide plate 33 .
  • the light guide plate 33 has a light diffusing portion 333 on the lower surface, which is the back side, and an emission surface 332 on the upper surface on the front side. That is, the light diffusing portion 333 and the emission surface 332 are provided facing each other.
  • the light diffusing portion 333 diffusely reflects the light impinging on the light diffusing portion 333 and breaks the total reflection condition, thereby causing the light to be emitted from the emission surface 332 in the positive direction of the z-axis.
  • the light diffusing portion 333 is, for example, a dot pattern of transparent ink whose arrangement is adjusted so that the light emitted from the light emitting surface 332 has an arbitrary luminance distribution, or a prism pattern composed of a plurality of grooves and ridges.
  • the light emitted from the light emitting surface 321 of the light source 32 enters the light guide plate 33 from the incident surface 331 formed on the side surface, and is optically path-changed in the z-axis positive direction by the light diffusion portion 333 on the lower surface. , is emitted in the positive direction of the z-axis from the emission surface 332 on the upper surface.
  • each light guide plate 33 functions as one surface light source, and the uniform surface light source device 30 is realized by superimposing the luminance distribution of the adjacent light guide plate 33 .
  • the light guide plate 33 may have a convex portion 335 covering the upper portion of the concave portion 334 on its front side.
  • the convex portion 335 has a shape that protrudes so as to cover at least a portion of the upper portion of the light source 32 .
  • a reflecting portion 336 is provided on the surface facing the light source 32 , which is the rear side of the convex portion 335 .
  • the reflecting portion 336 reflects the light that does not enter the incident surface 331 from the light source 32 but passes directly upward.
  • the reflecting portion 336 reflects the light guided to the convex portion 335 after being incident on the incident surface 331 in the positive direction of the z-axis.
  • the shape and size of the concave portion 334 and the convex portion 335 are not limited as long as the symmetry of the luminance distribution of each light emitting region is maintained.
  • FIG. 5 is a perspective view showing the partition 34 of Embodiment 1.
  • FIG. 6 and 7 are front sectional views showing the planar light source device 30 of Embodiment 1.
  • FIG. 6A and 6B are cross-sectional views taken along the line AA' in FIG. 3
  • FIG. 6A is a cross-sectional view of the planar light source device 30, and FIGS. It is a sectional view.
  • 7A and 7B are cross-sectional views taken along the line BB' of FIG. 3
  • FIG. 7A is a cross-sectional view of the planar light source device 30, and FIGS. It is a sectional view.
  • FIG. 8 is a perspective view showing the partition wall 34 of Embodiment 1.
  • FIG. 6A and 7A the paths of light are indicated by dashed arrows.
  • the partition wall 34 surrounds each of the plurality of light guide plates 33 so as to include one light guide plate 33 and the corresponding light source 32 (more specifically, its light emitting surface 321). Thereby, the partition wall 34 divides the light emitting area of the planar light source device 30 with respect to the display panel 10 into a plurality of light emitting areas.
  • the partition wall 34 corresponds to the light emitting area after division with the reflecting sheet 35 interposed therebetween on the mounting surface, which is the front side of the light source substrate 31 and the surface on which the light source 32 is mounted.
  • Each of the plurality of light guide plates 33 arranged in a row is surrounded so as to include at least the light emitting surface 231 of the corresponding light source 32 . As a result, a fixed height region on the mounting surface of the light source substrate 31 is physically divided into a plurality of regions.
  • the partition 34 has a lattice shape when viewed from the front side of the display device 100 as shown in FIG. 5, and is formed of, for example, highly reflective white resin and metal.
  • the partition 34 includes a first partition 341 located between the light guide plates 33 shown in FIG. 6 and a second partition 342 surrounding the outermost periphery of the light emitting region of the planar light source device 30 shown in FIG.
  • a first partition 341 located between the light guide plates 33 shown in FIG. 6 and a second partition 342 surrounding the outermost periphery of the light emitting region of the planar light source device 30 shown in FIG.
  • divided light-emitting regions are formed in which one light guide plate 33 and one light source 32 are arranged as described above.
  • the light guide plate 33 is completely surrounded on the side surfaces by the cells formed by the partition walls 34 and is separated from the adjacent light guide plate 33 .
  • the first partition wall 341 includes a vertical portion 341a having a wall surface parallel to the z-axis, and a tapered portion 341b having a wall surface that tapers in the positive direction of the z-axis above the vertical portion 341a. may contain.
  • the first partition 341 may be arranged with a gap d1 between adjacent light guide plates 33 . By providing the gap d1, it becomes easier to fit the light guide plate 33 into the partition wall 34 when manufacturing the planar light source device 30 .
  • the gap d1 is a distance that allows the light emitted from the side surface of the light guide plate 33 to be sufficiently reflected inside the light guide plate 33, and preferably 0 mm ⁇ d1 ⁇ 0.2 mm.
  • the gap d1 may be omitted.
  • the first partition wall 341 is switched from the vertical portion 341a to the tapered portion 341b at the position of the emission surface 332 of the light guide plate 33, but the switching position may be higher than the emission surface 332. Good or low.
  • the total height of the vertical portion 341a and the tapered portion 341b is called H1.
  • the slope of the tapered portion 341b is referred to as ⁇ 1.
  • the gradient ⁇ 1 is the degree of inclination of the wall surface of the tapered portion 341b with respect to the y-axis in the z-axis sectional view.
  • a preferable gradient ⁇ 1 is 30 degrees ⁇ 1 ⁇ 60 degrees.
  • the second partition wall 342 includes a vertical portion 342a having a wall surface parallel to the z-axis, and a tapered portion 342b having a wall surface that tapers in the positive direction of the z-axis above the vertical portion 342a. may contain.
  • the tapered portion 342b may be inclined only on the light guide plate 33 side.
  • the second partition 342 may be arranged with a gap d1 between it and the light guide plate 33, similarly to the first partition 341. It may be higher or lower than 332.
  • the total height of the vertical portion 342a and the tapered portion 342b is called H2. Also, as shown in FIG.
  • the slope of the tapered portion 342b is referred to as ⁇ 2.
  • the gradient ⁇ 2 is the degree of inclination of the wall surface of the tapered portion 342b with respect to the y-axis in the z-axis sectional view.
  • a preferable gradient ⁇ 2 is 10 degrees ⁇ 2 ⁇ 30 degrees.
  • the vertical portions 341a and 342a of the partition wall 34 reflect the light emitted from the side surface of the light guide plate 33 and return the light to the inside of the light guide plate 33. use efficiency can be improved.
  • the tapered portions 341b and 342b of the partition wall 34 reflect the light emitted from the emission surface 332 or the side surface of the light guide plate 33 and leaking to other adjacent divided light emitting regions in the positive direction of the z-axis. As a result, it is possible to suppress leakage light to other adjacent light-emitting regions after division.
  • the partition walls 34 have the effect of suppressing leakage light from each divided light emitting region to other adjacent divided light emitting regions. may not be completely suppressed. For example, part of the light reflected by the tapered portions 341b and 342b may leak to other adjacent divided light emitting regions. In addition, the light may leak from the light emitting surface 332 of the light guide plate 33 beyond the upper portion of the first partition wall 341 to another adjacent light emitting area after division. Therefore, for example, when all the light sources 32 are turned on, the brightness increases due to leakage light from the eight adjacent light emitting regions after division except for the light emitting region after division on the outermost periphery of the planar light source device 30 .
  • the outermost divided light-emitting region tends to be dark because the number of adjacent divided light-emitting regions is small. Therefore, since the tapered portion 342b of the second partition 342 also utilizes leaked light from other than the adjacent light-emitting regions after division, the height H2 of the second partition 342 is equal to the height of the first partition 341. It should be higher than height H1. Also, the height H2 of the second partition wall 342 is preferably the height at which the optical sheet group 20 is provided so that light does not leak outside the display area of the display panel 10 . In FIG. 1 , the second partition 342 has a height at which the diffusion plate 21 of the optical sheet group 20 is provided, and the diffusion plate 21 is supported by the second partition 342 .
  • the partition wall 34 may have a hole 343 for accommodating at least part of the light source 32 .
  • FIG. 8 shows an example in which the light sources 32 are arranged at the corners of the cells formed by the partition walls 34, and the holes 343 are formed in the vertical portions 341a and 342a.
  • the light source 32 can be arranged away from the center of the light guide plate 33 toward the partition wall 34 side. Thereby, the light source 32 can widen the light irradiation area to the light guide plate 33 .
  • the area of the reflecting portion 336 of the light guide plate 33 directly above the light source 32 can be reduced, and the influence of the dark portion that may occur directly above the light source 32 can be reduced.
  • the light irradiation area from the light source 32 to the light guide plate 33 is set within the width of the incident surface 331 of the light guide plate 33 .
  • the reflective sheet 35 is a sheet-like member sandwiched between the light source substrate 31 and the light guide plate 33 .
  • a plurality of holes are formed in the reflecting sheet 35 , and the light sources 32 protrude from the holes toward the front side of the reflecting sheet 35 .
  • the light emitted from the light source 32 and emitted through the light guide plate 33 the light emitted from the surface of the light guide plate 33 opposite to the emission surface 332 is reflected by the reflection sheet 35 and returns to the light guide plate 33 again. , is emitted from the emission surface 332 of the light guide plate 33 .
  • the mounting substrate of the light source 32 may be painted white, but the reflective sheet 35 has a higher reflectance than the white paint and can improve the light utilization efficiency.
  • the planar light source device 30 and the display device 100 including the planar light source device 30 according to the present embodiment are arranged corresponding to the respective light emitting regions after division, and the light incident from the side surface is emitted from the top surface.
  • the partition wall 34 blocks the light emitted from the side surface or the emission surface 332 of the light guide plate 33 toward the other adjacent light-emitting regions after division. Therefore, it is possible to suppress leakage light from each divided light emitting region to other adjacent divided light emitting regions.
  • FIG. 9 is a front cross-sectional view showing a planar light source device according to a comparative example.
  • a direct type planar light source device in which the light emitting surfaces 321 of the plurality of light sources 32 are arranged behind one display panel 10 so as to face the display panel 10 is generally used.
  • FIG. 9 shows a direct type planar light source device in which the light emitting surfaces 321 of the plurality of light sources 32 are arranged behind one display panel 10 so as to face the display panel 10 is generally used.
  • the plurality of light sources 32 can illuminate the entire display area as a whole, and individually illuminate the entire luminous area corresponding to the divided luminous area. placed so that it can be
  • the direct type planar light source device in order to illuminate the entire corresponding light emitting area after division from behind the display panel 10, it is necessary to secure a sufficient projection distance from the light source 32 to the optical sheet group 20. Thinning is difficult. For example, if the projection distance is shortened for thinning, the light emitting area after each division becomes wider with respect to the projection distance. Therefore, it is necessary to arrange a plurality of light sources 32 at the same time.
  • the planar light source device 30 of the light guide type in which the light is incident from the side surface of the light guide plate 33 and the light is emitted from the upper surface is provided.
  • 33 is provided, and independently drivable light sources 32 are arranged with respect to each light guide plate 33, and a partition wall 34 surrounds each light guide plate 33 including the light source 32 corresponding to the light guide plate 33.
  • edge-type local dimming that is advantageous for thinning.
  • each light guide plate 33 functions as a surface light source, it is easy to ensure the uniformity of luminance on the screen, and luminance unevenness is less likely to occur.
  • FIG. 10 is a cross-sectional plan view showing another example of the planar light source device 30 according to the first embodiment.
  • the directions of the light sources 32 are arranged so as to be different from each other in adjacent light emitting regions after division.
  • the directions of the light guide plates 33 are changed so that only one of the four corners of the light guide plates 33 that are closely butted against each other is provided with the light source 32 .
  • the brightness of the surface opposite to the light emitting surface 321 of the light source 32 arranged at one corner can be compensated for by light leaked from the other three corners.
  • the planar light source device 30 in which one light source 32 is provided for one light guide plate 33 can be realized.
  • the plurality of light sources 32 are arranged in different directions as shown in FIG. 10, it is not easy to mount the light sources 32 on the board.
  • the preferred arrangement of the light sources 32 is, first, the corners of the light guide plates 33, that is, the corners of the light emitting regions. Furthermore, from the viewpoint of ease of mounting, as shown in FIG. 3, it is more preferable to arrange so that the optical axes of the plurality of light sources 32 provided in each light emitting region after division are the same. That is, it is preferable to install the light emitting surfaces 321 of the plurality of light sources 32 in the same direction.
  • the planar light source device 30 of the present embodiment includes a plurality of light guide plates 33 corresponding to the number of divisions of the light emitting region, and one light source 32 is provided for each light guide plate 33, thereby facilitating control.
  • the light sources 32 may be arranged at the corners of the light guide plate 33. In this case, uneven brightness on the screen can be further reduced.
  • the light source 32 By arranging the light source 32 at the corner of the light guide plate 33, even if the spread angle of the light emitted from the light source 32 is small, the light emitted from the light source 32 spreads sufficiently within the light guide plate 33, and the light source 32 laterally spreads. This is because a dark portion is less likely to occur in the region of .
  • the light source 32 may be provided on a side surface other than the corner portion.
  • the planar light source device 30 may be arranged so that the optical axes of the plurality of light sources 32 are the same, in which case the light sources 32 can be easily mounted on the board.
  • FIG. 11 is a front sectional view showing the planar light source device 30 of Embodiment 1.
  • FIG. The path of light is indicated by dashed arrows.
  • the light guide plate 33 of the planar light source device 30 shown in FIG. 11A does not have the projections 335 .
  • the area a1 on the front side of the light source 32 indicated by the ellipse in FIG. 11(A) does not have sufficient brightness and tends to be a dark area.
  • the light guide plate 33 with a convex portion 335 as shown in FIG. 11B.
  • the convex portion 335 is formed to protrude so as to cover at least a portion of the front side of the light source 32 , and a reflecting portion 336 is provided on the rear side of the convex portion 335 facing the light source 32 .
  • the reflecting portion 336 blocks the light from the light source 32 that does not enter the incident surface 331 and escapes to the front side of the display device 100, thereby suppressing the generation of a high-brightness spot in the region a2.
  • the reflecting portion 336 reflects the light guided to the convex portion 335 after being incident on the incident surface 331 in the positive direction of the z-axis, thereby reducing the dark portion of the area a1 that may occur due to the light shielding of the reflecting portion 336 described above.
  • FIG. 12 is a cross-sectional plan view showing another example of the planar light source device 30 of Embodiment 1.
  • FIG. The path of light is indicated by dashed arrows.
  • the partition wall 34 shown in FIG. 12(A) does not have the tapered portion 341b, and has only the vertical portion 341a. Note that the same applies to the second partition wall 342 as well. That is, the entire wall surface of the partition 34 shown in FIG. 12A is parallel to the z-axis. Even with such a partition wall 34, light emitted from the side surface or the emission surface 332 of the light guide plate 33 in the direction of other adjacent divided light emitting regions can be blocked.
  • the partition wall 34 shown in FIG. 12B does not have the vertical portion 341a, and has only the tapered portion 341b. That is, the partition 34 shown in FIG. 12B has an acute angle between the wall surface of the partition 34 on the light guide plate 33 side and the bottom surface of the partition 34, and the partition 34 as a whole is tapered. Even with such a partition wall 34, by blocking light emitted from the side surface or the emission surface 332 of the light guide plate 33 in the direction of other adjacent light emitting regions after division, Leakage of light to other light emitting regions after division can be suppressed.
  • the partition wall 34 shown in FIG. 12A most of the light emitted from the emission surface 332 or the side surface of the light guide plate 33 is reflected inside the light guide plate 33, so that a dark portion is formed directly above the partition wall 34. There is a possibility that brightness unevenness will occur on the screen, such as being likely to occur.
  • the partition 34 shown in FIG. 12B the light emitted from the emission surface 332 or the side surface of the light guide plate 33 is more likely to be reflected in the positive direction of the z-axis than inside the light guide plate 33 .
  • FIG. 13 is a cross-sectional plan view showing the planar light source device 30 of Embodiment 1, in which the paths of light are indicated by dashed arrows.
  • the vertical portions 341a and 342a reflect the light emitted from the side surfaces of the light guide plate 33 and return the light to the inside of the light guide plate 33, thereby improving the light utilization efficiency.
  • the surface brightness distribution of the emission surface 332 becomes more uniform.
  • the tapered portions 341b and 342b reflect the light emitted from the emission surface 332 or the side surface of the light guide plate 33 and leaking to other adjacent divided light emitting regions in the positive direction of the z-axis. As a result, it is possible to suppress leakage light to other adjacent light-emitting regions after division. As a result, it is possible to increase the light utilization efficiency and suppress leakage light from each divided light emitting region to other adjacent divided light emitting regions during local dimming control.
  • the height H2 of the second partition 342 should be higher than the height H1 of the first partition 341 .
  • the tapered portion 342b of the second partition wall 342 can also reflect, in the positive direction of the z-axis, leaked light from other than the other adjacent light-emitting regions after division. Therefore, it is possible to improve the luminance of the light-emitting region after the division of the outermost periphery of the planar light source device 30, which tends to become dark, and improve the luminance uniformity on the screen.
  • FIG. 14 is a front sectional view showing a planar light source device 30 according to Embodiment 2.
  • FIG. The planar light source device 30 of the second embodiment and the display device 100 including the planar light source device 30 are characterized in that a lens 337 is provided on the side surface of the light guide plate 33 on which the light incident surface 331 is formed. Other configurations are the same as those of the first embodiment.
  • the incident surface 331 of the light guide plate 33 has a lens 337 .
  • FIG. 14 shows an example in which the incident surface 331 of the light guide plate 33 is shaped like a lens 337 .
  • Embodiment 1 it was assumed that the light source 32 had a wide light emitting surface 321 in order to irradiate a wide range.
  • Embodiment 2 is an example that assumes a case where a smaller light source 32 is used.
  • a lens 337 is provided on the side surface of the light guide plate 33 on which the incident surface 331 of the light guide plate 33 where the light is incident is formed in order to increase the spread angle of the light on the incident surface 331. .
  • the planar light source device 30 and the display device 100 including the planar light source device 30 according to the present embodiment are arranged corresponding to the respective light emitting regions after division, and the light incident from the side surface is a plurality of light guide plates 33 for emitting light from the upper surface, a plurality of light sources 32 that can be driven independently of each other, and each of the plurality of light guide plates 33, one light guide plate 33 and one light source 32 are included. and a surrounding partition wall 34 .
  • the partition wall 34 blocks the light emitted from the side surface or the emission surface 332 of the light guide plate 33 toward the other adjacent light-emitting regions after division. Therefore, it is possible to suppress leakage light from each divided light emitting region to other adjacent divided light emitting regions.
  • the lens 337 is provided on the side surface of the light guide plate 33 on which the light incident surface 331 is formed.
  • the spread angle of light on surface 331 can be increased. This makes it possible to achieve the same effect as in the first embodiment with a smaller and less expensive light source 32 .
  • the incident surface 331 cannot have a complicated lens shape.
  • the light source 32 and the incident surface 331 are in one-to-one correspondence, so it is possible to design an optimal and complicated lens 337 depending on the light source 32 to be used.
  • the optical sheet group 20 is composed of the diffuser plate 21, the diffuser sheet 22, the two prism sheets 23, and the polarizing sheet 24 in this order from the back side of the display device 100, but they do not necessarily have the same configuration.
  • the shape of the light guide plate 33 when viewed from the positive direction of the z-axis is preferably rectangular, but may be polygonal such as rhombus, triangle, pentagon, hexagon, heptagon, and octagon.
  • the light diffusing portion 333 of the light guide plate 33 may break the total reflection condition on the emission surface 332 of the light guide plate 33 . For example, dot pattern printing with white ink, sandblasting, fine structure, or lens shape may be used.
  • the reflection sheet 35 processed according to the shape of the partition walls 34 may be attached to a member made of another material. It may be coated with material.
  • the reflective tape may be attached directly to the end face on the light guide plate 33 side.
  • the partition wall 34 may block, rather than reflect, the light emitted from the light guide plate 33 to other adjacent light emitting regions after division. Even in this case, it is possible to suppress leakage light from each divided light emitting region to other adjacent divided light emitting regions during local dimming control.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Planar Illumination Modules (AREA)

Abstract

La présente invention concerne un dispositif de source de lumière plane (30) et un dispositif d'affichage (100) pourvu du dispositif de source de lumière plane (30) sont chacune pourvues : d'une pluralité de plaques de guide de lumière (33) qui sont disposées correspondant à des régions d'émission de lumière divisées et qui émettent chacune, à partir de la surface supérieure, une lumière ayant pénétré à partir d'une surface latérale ; d'une pluralité de sources de lumière (32) qui peuvent être actionnées de manière indépendante l'une de l'autre ; et d'une paroi de séparation (34) qui entoure chaque plaque de la pluralité de plaques de guide de lumière (33) de manière à inclure une plaque de guide de lumière (33) et une source de lumière (32). Avec cette configuration, la lumière émise, depuis la surface latérale ou une surface d'émission (332) de l'une quelconque des plaques de guide de lumière (33), dans une direction d'une autre des régions d'émission de lumière divisées est protégée par la paroi de séparation (34). Par conséquent, il est possible de supprimer une fuite de lumière provenant de chacune des régions d'émission de lumière divisées à une région correspondante parmi les autres régions d'émission de lumière divisées adjacentes.
PCT/JP2021/012340 2021-03-24 2021-03-24 Dispositif de source de lumière plane et dispositif d'affichage WO2022201378A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP2021/012340 WO2022201378A1 (fr) 2021-03-24 2021-03-24 Dispositif de source de lumière plane et dispositif d'affichage
JP2023508274A JP7341371B2 (ja) 2021-03-24 2021-03-24 面状光源装置及び表示装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/012340 WO2022201378A1 (fr) 2021-03-24 2021-03-24 Dispositif de source de lumière plane et dispositif d'affichage

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009110145A1 (fr) * 2008-03-07 2009-09-11 シャープ株式会社 Élément électroluminescent, dispositif d'éclairage et dispositif d'affichage à cristaux liquides
JP2010524184A (ja) * 2007-04-12 2010-07-15 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ 改善された導光器及び光出力装置
WO2017002307A1 (fr) * 2015-07-01 2017-01-05 パナソニックＩｐマネジメント株式会社 Dispositif de rétroéclairage et dispositif d'affichage à cristaux liquides
JP2018137044A (ja) * 2017-02-20 2018-08-30 三菱電機株式会社 面状光源装置および表示装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010524184A (ja) * 2007-04-12 2010-07-15 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ 改善された導光器及び光出力装置
WO2009110145A1 (fr) * 2008-03-07 2009-09-11 シャープ株式会社 Élément électroluminescent, dispositif d'éclairage et dispositif d'affichage à cristaux liquides
WO2017002307A1 (fr) * 2015-07-01 2017-01-05 パナソニックＩｐマネジメント株式会社 Dispositif de rétroéclairage et dispositif d'affichage à cristaux liquides
JP2018137044A (ja) * 2017-02-20 2018-08-30 三菱電機株式会社 面状光源装置および表示装置

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JP7341371B2 (ja) 2023-09-08

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