JP5568263B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a direct-type liquid crystal display device in which a light source in a backlight is disposed directly below a liquid crystal panel.

  The liquid crystal display device includes a liquid crystal panel and a backlight light source module (hereinafter simply referred to as a backlight in this specification). In reducing the thickness of the liquid crystal display device, the backlight is thin while maintaining or improving the optical uniformity by the design of the optical film such as a diffusion plate, a diffusion sheet, and a prism sheet constituting the backlight. Is made.

  In addition, the backlight includes a light source and an optical film such as a light guide member and a diffusion plate, and a light emitting element that emits light in a spot shape by a light emitting diode light source or the like has been used as the light source. ing. There is also a so-called direct-type liquid crystal display device in which the light-emitting diode light source is disposed directly under the liquid crystal panel. This direct type liquid crystal display device is mainly used for a medium-sized or large-sized liquid crystal display device, and includes an optical film such as a light guide member and a diffusion plate so as to be sandwiched between a liquid crystal panel and a light-emitting diode light source. .

  There are several examples of countermeasures against optical uniformity in reducing the thickness of the backlight with respect to the light source of the backlight. For example, Patent Document 1 is known. In Patent Document 1, a light source having strong directivity and a light guide having a radiation surface in the radiation direction of the light source are formed, and light from the light source is supplied to the radiation surface of the light guide at a predetermined ratio. The surface illumination light source device provided with the radiation-side reflecting means for reflecting the light is described, and the illumination light uniformed as a whole can be obtained.

JP 2008-27886 A

  Here, even in a direct type liquid crystal display device, when the thickness is reduced, the optical distance from the light source of the backlight to the liquid crystal panel is reduced, and uneven brightness and chromaticity of the backlight are likely to be remarkable. Therefore, it is a problem to achieve both reduction in thickness and optical uniformity. Further, a backlight using a light emitting diode or the like as a light source needs to be designed in consideration of its light distribution in order to improve optical uniformity.

  In view of the above problems, the present invention increases the optical uniformity even when the backlight is thinned in a direct-type liquid crystal display device using a light-emitting element that emits light by a light-emitting diode light source or the like. It is an object of the present invention to provide a liquid crystal display device capable of achieving the above.

  In order to solve the above problems, a liquid crystal display device according to the present invention is a liquid crystal display device including a liquid crystal panel and a backlight, and the backlight is disposed below the liquid crystal panel and the liquid crystal panel And a light guide member disposed on the upper side of the light emitting element and below the liquid crystal panel, and the light guide member guides light from the light emitting element. A light emitting surface that emits light in a planar shape on the liquid crystal panel side, and the light emitting surface has a concave portion formed immediately above the light emitting element, and a dot or line pattern for emitting light Are distributed so as to become dense as they move away from the recess, and the recess is formed with an inner surface inclined so as to taper in the depth direction of the recess. .

  In one embodiment of the liquid crystal display device according to the present invention, the recess is formed so that the cross section is V-shaped by the inner surface inclined at an angle of inclination α of 35 degrees ≦ α ≦ 55 degrees with respect to the light emitting surface. In addition, the recess is formed so as to expand further than a portion where the light emitting element emits light, and a center portion of the recess is disposed so as to be aligned with a center of the light emitting portion. It is good.

  In one aspect of the liquid crystal display device according to the present invention, the concave portion is formed in a V-shaped cross section by the inner surface inclined at an inclination angle α of 45 degrees ≦ α ≦ 50 degrees with respect to the light emitting surface. This may be a feature.

  In one aspect of the liquid crystal display device according to the present invention, the recess includes a first inner surface that is located at a central portion of the recess and forms a bottom portion, and a side surface that extends from the bottom portion to the edge of the recess. A second inner surface, wherein the first inner surface and the second inner surface have different inclination angles with respect to the light emitting surface, and the inclination angle of the first inner surface is the second inner surface. The first inner surface is disposed so as to be aligned with the center of the light emitting portion of the light emitting element and is substantially overlapped with the light emitting portion. The two inner surfaces may be formed so as to further spread from the light emitting portion around the first inner surface.

  In one mode of the liquid crystal display device according to the present invention, the concave portion is formed in a groove shape formed linearly in one direction, and the dot-shaped or line-shaped pattern is a groove formed linearly. It may be characterized by being distributed so as to become denser as it moves away from the concave portion of the mold.

  In one mode of the liquid crystal display device according to the present invention, the concave portion is formed in a conical shape, and the dot-like or line-like pattern is concentrically distributed so as to become denser as the distance from the concave portion increases. This may be a feature.

  In one aspect of the liquid crystal display device according to the present invention, the inner surface is formed to be curved in an arc shape, and the concave portion is a groove shape that is linear in one direction, and the inner surface is curved in an arc shape. The concave portion is formed so as to expand further than the portion where the light emitting element emits light, and the center portion of the concave portion is arranged so as to be aligned with the center of the light emitting portion. The dot-shaped or line-shaped pattern may be distributed in parallel with the concave portion that is linear so as to become denser as the distance from the concave portion increases.

  In one mode of the liquid crystal display device according to the present invention, the central portion of the concave portion may be formed flat.

  Also, in one aspect of the liquid crystal display device according to the present invention, a plurality of light emitting elements that emit light of different light emission colors to form a white color are formed below the concave portion of the light guide member. The plurality of light emitting elements arranged along a mold and arranged adjacent to each other in a direction different from the groove portion are arranged so that light emission colors are complemented with each other. It may be characterized by that.

  Moreover, in one aspect of the liquid crystal display device according to the present invention, the light guide member has an incident portion for allowing light from the light emitting element to be incident on a back surface which is a back side with respect to the light emitting surface, Diffuse reflection means may be provided in a part away from the incident part.

  Moreover, in one aspect of the liquid crystal display device according to the present invention, the light guide member has an incident portion for allowing light from the light emitting element to be incident on a back surface which is a back side with respect to the light emitting surface, It may be characterized in that dot-like or line-like patterns for reflecting light to the light emitting surface and emitting light are distributed so as to become dense as they move away from the incident portion.

  In the liquid crystal display device according to one aspect of the present invention, the light emitting element has an optical axis in a direction substantially perpendicular to the liquid crystal panel, and an emission luminance of the light emitting element is relative to the optical axis. In addition to being distributed symmetrically, it may have a peak in a direction inclined with respect to the optical axis.

  In the liquid crystal display device according to the aspect of the invention, the light emitting element includes a light emitting diode and a lens portion that covers the light emitting diode from above, and the lens portion emits light toward the light guide member. And a concave portion having a V-shaped cross section that is symmetric with respect to the optical axis is formed, and the concave portion of the light guide member is formed by the concave portion of the lens portion. It may be characterized by having a shape corresponding to the shape.

  In one aspect of the liquid crystal display device according to the present invention, the emission luminance of the light emitting element is distributed symmetrically with respect to the direction in which the concave portion is formed in a linear groove shape, and has a bimodal peak. It may be characterized by having.

  In the liquid crystal display device according to one aspect of the present invention, the light emitting element has an optical axis in a direction substantially perpendicular to the liquid crystal panel, and an emission luminance of the light emitting element is relative to the optical axis. It may be characterized by having a ring-shaped peak distributed point-symmetrically.

  In order to solve the above problems, a liquid crystal display device according to the present invention is a liquid crystal display device including a liquid crystal panel and a backlight, and the backlight includes a plurality of light emitting elements arranged below the liquid crystal panel. A plurality of light guide members that are disposed on the upper side of the plurality of light emitting elements and below the liquid crystal panel, and are provided for each one or a plurality of light emitting elements of the plurality of light emitting elements; Each of the light guide members has a light emitting surface that guides light from the one or more light emitting elements and emits light in a planar shape on the liquid crystal panel side. A recess is formed at a position directly above the light emitting element, and a dot-like or line-like pattern for emitting light is distributed so as to become dense as it leaves the recess, and the recess is To taper in the depth direction of the recess Has an inner surface which is inclined is formed, characterized in that.

  Moreover, in one aspect of the liquid crystal display device according to the present invention, the light guide member has a side surface of the light guide member inclined such that the light emitting surface is wider than a surface on the side where the light emitting element is disposed. This may be a feature.

  In one aspect of the liquid crystal display device according to the present invention, the backlight includes a substrate on which the plurality of light emitting elements are arranged, and the light guide member is located upward from a side of the one or the plurality of light emitting elements. Diffuse reflection means for diffusing and reflecting light from the one or a plurality of light emitting elements is disposed on the surface of the light guide member that contacts the substrate so that the light guide member is in contact with the substrate. It may be characterized by that.

  According to the present invention, in a direct liquid crystal display device, it is possible to improve the optical uniformity of the backlight while reducing the thickness of the backlight.

1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 1. FIG. 1 is a top view of a direct type backlight according to Embodiment 1. FIG. It is sectional drawing which shows the mode of the light emitting diode package light source (light emitting element) which concerns on Embodiment 1. FIG. 3 is a graph showing a radiation angle distribution of the light emitting element according to Embodiment 1. FIG. 3 is a top view of the light emitting element according to Embodiment 1. FIG. 3 is a graph showing a radiation angle distribution of the light emitting element according to Embodiment 1. FIG. It is a figure which shows the mode of the cross section of the light emitting element which concerns on Embodiment 1, and a light guide sheet. 6 is a graph showing a calculation of a relationship between a radiation angle θ from the light emitting element according to Embodiment 1 and an angle at which light emitted at the radiation angle θ is reflected by the inner surface of the recess and is incident on the light emitting surface. When the light emitting element which concerns on Embodiment 1 has radiation angle distribution as shown in FIG. 4, it is a graph which shows the intensity | strength of each angle x which the inner surface of a recessed part forms, and angle 2x-psi which injects into a light emitting surface. 4 is a graph showing a relationship between an angle emitted from a side wall of the light emitting element according to Embodiment 1 and a refraction angle in the light guide sheet. It is sectional drawing which shows the modification of the light emitting element which concerns on Embodiment 1, and a light guide sheet. It is a figure which shows a mode that the dot pattern for radiate | emitting light was formed so that it might become dense as it distanced from a recessed part on the light emission surface of the light guide sheet which concerns on Embodiment 1. FIG. It is a modification of the light guide sheet which concerns on Embodiment 1, and is a figure which shows a mode that the pattern of the triangular groove | channel shape for radiating | emitting light was formed so that it might become dense as it distanced from a recessed part on the light emission surface. It is a figure which shows an example of a mode that the dot pattern on the light emission surface of the light guide sheet which concerns on Embodiment 1 is arrange | positioned. It is a figure which shows a mode that the some light guide sheet was arrange | positioned in parallel on the backlight housing | casing which concerns on Embodiment 1. FIG. It is a figure which shows the mode of the cross section of the light guide sheet which concerns on Embodiment 2, and a light emitting element. It is a figure which shows a mode that the light guide sheet which concerns on Embodiment 2, and three light emitting elements which light-emit to RGB are arrange | positioned. It is a figure which shows a mode that the three light emitting elements which light-emit to the light guide sheet and RGB which concern on the modification of Embodiment 2 are arrange | positioned. It is a figure which shows a mode that the light guide sheet and light emitting element which concern on the modification of Embodiment 2 are laid down and arrange | positioned on a backlight housing | casing. 6 is a top view of a light emitting device according to Embodiment 3. FIG. It is a figure which shows a mode that the dot pattern was arrange | positioned on the light emission surface of the light guide sheet which concerns on Embodiment 3. FIG. It is a figure which shows a mode that the some light guide sheet was spread | laid in parallel and arrange | positioned on the backlight housing | casing which concerns on Embodiment 3. FIG.

  Hereinafter, each embodiment according to the present invention for solving the above-mentioned problems will be described in detail with reference to the drawings. The liquid crystal display device according to each embodiment of the present invention described below is not limited by these embodiments, and may be implemented in different forms within the scope of the technical idea. Forms obtained by combining forms disclosed in the embodiments are also included in the present invention.

[Embodiment 1]
First, Embodiment 1 according to the present invention will be described with reference to FIGS. FIG. 1 shows a cross section of a configuration of a liquid crystal display device including a liquid crystal panel, a light emitting diode package light source serving as a light source of a backlight, a light guide member, and an optical film such as a prism sheet. The liquid crystal display device shown in this embodiment is a medium to large-sized liquid crystal display device on which a liquid crystal panel and a direct type backlight are mounted. In FIG. 1, a backlight housing 1, a printed circuit board 2, a light emitting diode package light source (light emitting element) 3 provided on the printed circuit board 2, and a white reflective sheet as a base, light from the light emitting element 3 is emitted. A backlight light source system is configured by the light guide sheet 4 that is a light guide member that guides light and emits light in a planar shape.

  Here, as shown in FIG. 3 to be described later, the light-emitting element 3 is obtained by introducing a phosphor into a resin in the vicinity of the light-emitting diode 18 that is a resin constituting the lens unit 20 or a blue light-emitting diode element, and photoexciting it. A white light source is configured. Further, in the backlight, a light guide sheet 4 is provided in the periphery so as to cover the upper side and the side of the light emitting element 3, and further on the upper side of the light guide sheet 4, a diffusion plate 5, a diffusion sheet 6, and a prism. The sheet 7 and the polarization reflection sheet 8 constitute a backlight optical system. Further, the liquid crystal panel includes a lower polarizing plate 9, a liquid crystal sealing glass substrate 10 equipped with a thin film transistor and a color filter, and an upper polarizing plate 11.

  When the upper surface of the liquid crystal display device is viewed, as shown in FIG. 2, the liquid crystal display device includes a backlight support housing 12, an area control divided light source 13 including a light emitting element 3 and a light guide sheet 4, and a drive circuit unit 14. . The liquid crystal display device according to the present embodiment employs area control in which a region where light is emitted from the backlight to the liquid crystal panel is controlled according to the video to be displayed. In the drive circuit unit 14, by setting an operation condition for irradiating the area control divided light source 13 to the area where the backlight light is required in accordance with the video signal, the backlight light source system corresponding to the area control can be functioned. . In the backlight according to the present embodiment, light emitting diodes that are point light sources are arranged and light is emitted in a planar shape by a light guide member to form a backlight corresponding to the area control. The light-emitting element 3 of the present embodiment has a configuration in which a lens is mounted on the light-emitting diode 18 to expand the radiation angle distribution. FIG. 3 shows the configuration of the light-emitting element 3. A wiring 16 is formed on a base material 15 made of resin or ceramic, a die bonding material 17 is then formed, and a light-emitting diode 18 is mounted thereon. Thereafter, the Au wire 19 is connected to the wiring 16.

  Next, the lens part 20 is closely attached to the light emitting diode 18 with a transparent silicone resin. In the present embodiment, the lens portion 20 made of transparent resin is formed such that its upper surface is curved in a concave lens shape, and further has a concave portion having a V-shaped groove shape directly above the light emitting diode 18. The tip of the V-shaped recess provided in the lens portion 20 of the light-emitting element 3 is positioned so as to overlap the center of the light-emitting diode 18, and close to the light-emitting diode 18 and the Au wire 19. The distance between them is close to 50-150 microns. Note that the light emitting element 3 has an actual size of the lens unit 20 of about 5 × 5 mm.

  FIG. 4 shows a radiation angle distribution from the light emitting diode 18 according to the present embodiment, and has a light emission distribution having a peak intensity that becomes bimodal at a radiation angle of about 60 °. The radiation angle distribution in the figure is a distribution in a direction perpendicular to one direction in which the groove-shaped concave portion of the lens unit 20 is formed in a straight line. By making the light of the light emitting diode 18 having the peak intensity of such a radiation angle distribution enter the light guide sheet 4 and propagate (light guide) so as to spread from directly above the light emitting diode 18, the light is emitted in the lateral direction. The radiant light flux is enlarged, and the uniformity of the surface light source is further improved.

  FIG. 5 is a view showing the upper surface of the light emitting element 3 of the backlight according to the present embodiment, and the concave portion in the lens portion 20 is formed by a groove shape that is linear in the vertical direction and has a triangular prism shape in cross section. Is done. Since the concave portion of the lens unit 20 according to the present embodiment has a triangular prism-shaped concave shape, in the case of the light emitting element 3 as shown in FIG. 5, the radiation angle distribution is set to have a peak in the left-right direction. it can. Further, in the vertical direction of FIG. 5, the radiation angle distribution of the light emitting element 3 is set so that the emission luminance is approximately the same level in a region having a low radiation angle, as shown in FIG.

  FIG. 7 is a diagram illustrating a cross-sectional state of the light emitting element 3 and the light guide sheet 4 according to the present embodiment. As shown in FIG. 7, the light emitting element 3 is first mounted on a printed circuit board 22 provided with a white reflective sheet 23 on the upper side, and the light emitting element 3 is electrically connected to the printed circuit board 22 to emit light. A light guide sheet 4 is provided so as to cover the element 3. At this time, the light guide sheet 4 covers and covers the lens portion 20 of the light emitting element 3 via an air layer, and a V-shape is directly above the light emitting element 3 (immediately above the light emitting diode 18). A concave portion that is a triangular groove shape is provided. As shown in FIG. 7, the concave portion of the light guide sheet 4 is further widened with respect to the concave portion of the lens portion 20 and the light emitting diode 18, and the light guide sheet 4 is formed in accordance with the concave portion of the lens portion 20. A recess is provided, and in the present embodiment, the two recesses are formed in a linear groove shape extending in one direction.

  Here, light emitted from the light emitting element 3 at an emission angle θ is first refracted at an angle ψ on the incident surface of the light guide sheet 4 and incident on an inclined surface having an angle x in the V-shaped triangular groove. Reflects at an angle 2x-ψ. As shown in FIG. 7, the three angles of the emission angle θ, the angle ψ, and the angle 2x−ψ are angles with reference to the normal direction with respect to the printed circuit board 22 on which the light emitting element 3 is installed. Moreover, the recessed part of the light guide sheet 4 is formed to have a tapered inner surface in the depth direction, and the inner surface of the recessed part in this embodiment is a slope of a triangular groove. In addition, an angle at which the inner surface is inclined with respect to the light emitting surface that emits light in a planar shape of the light guide sheet 4 is an inclination angle α (that is, α = 90 degrees−x). In the light guide sheet 4, a dot pattern serving as an emission means to be described later that emits the guided light to the light emitting surface is arranged so as to become denser as the distance from the concave portion increases. The light incident on the inside is totally reflected by the inner surface of the recess, propagates in the horizontal direction in the figure (hereinafter referred to as the horizontal direction or the propagation direction) so as to further spread from the recess, and emits light in a planar shape. The uniformity of the light emitting surface is improved.

  Here, as the light guide sheet 4, a refractive index of about 1.4 to 1.6 is used, but in this embodiment, the light guide sheet 4 having a refractive index of 1.4 is used. In the light guide sheet 4, the critical angle at which the light guided inside is totally reflected is about 45.6 degrees. Further, the condition under which the light having the angle ψ refracted by the light guide sheet 4 is totally reflected by the inner surface of the recess is α + ψ ≧ 45.6 degrees. Further, the light totally reflected by the inner surface of the concave portion is totally reflected by the upper surface (light emitting surface) of the light guide sheet 4, so that the light propagates further from the concave portion. Since the condition of total reflection on the upper surface is 2x−ψ ≧ 45.6 degrees, the angle 2x−ψ can be adjusted to spread and propagate in the lateral direction of the light guide sheet 4.

  When the inclination angle α of the inner surface of the recess is gentle, the light emitted from the light emitting element 3 at a high angle side emission angle is totally reflected and guided laterally so as to spread further from the recess, When the inclination angle α is steep, the light emitted from the light emitting element 3 at the low-angle side emission angle is totally reflected and easily guided so as to spread laterally. Therefore, for example, in the bottom part (first inner surface) of the concave part located in the central part directly above the light emitting element 3, the inclination angle is made steep, and the side part (between the bottom part and the edge located in the central part of the concave part) In the second inner surface), the inner surface inclination angle may be set in a plurality of stages so that the inclination angle becomes gentler than the bottom inclination angle. In this case, specifically, in consideration of the incident angle 2x−ψ to the light emitting surface of the light guide sheet 4, the inclination angle α at the center of the recess is set to 40 degrees or more and 60 degrees or less, and the side surface of the recess. Is inclined in two stages such that the inclination angle α is set to 25 degrees or more and 45 degrees or less.

Here, FIG. 8 shows the result of calculating the relationship between the emission angle θ from the light emitting element 3 and the angle 2x−ψ reflected by the inner surface of the recess. Here, the angle reflected by the inner surface of the recess is represented by 2x−ψ = 2x−sin ⁻¹ (sin θ / n). n is the refractive index of the material in the light guide sheet 4, and n = 1.4. From FIG. 8, the inclination angle of the inner surface having a V-shaped tapered section is suitable when 35 degrees ≦ α ≦ 55 degrees (when 35 degrees ≦ x ≦ 55 degrees), and more preferably 45 degrees ≦ α ≦ 50 degrees (when 40 degrees ≦ x ≦ 45 degrees). FIG. 8 shows a relationship in which the angle x, which is half of the tip angle of the V-shaped groove, is 25 degrees to 45 degrees, but the case where the angle x is 50 degrees or more is omitted. In the case of x = 50 degrees or 55 degrees, the inner surface of the concave portion has a gentler inclination with respect to the light emitting surface than in the case of x = 45 degrees, and therefore the emission angle θ = 0 degrees in the optical axis direction of the light emitting element 3 , And the light in the vicinity thereof is difficult to be totally reflected, but the light at the emission angle of the other part is totally reflected by the recess and the light emitting surface, and is guided so as to propagate and spread laterally from the recess. Is improved as the inclination angle of the inner surface of the V-shaped recess.

FIG. 9 shows a V-shaped triangular groove-shaped recess having an inner surface of x = 30 degrees, 35 degrees, 40 degrees, and 45 degrees when the light emitting element 3 has a radiation angle distribution as shown in FIG. It is a figure which shows the relationship between the angle 2x-psi which reflects and injects into a light emitting surface, and its relative intensity. This figure corresponds to the right half of the radiation angle distribution in the angle range of 0 to 90 degrees in FIG. 4, the angle 2x−ψ incident on the light emitting surface is shown on the horizontal axis, and the relative intensity is shown on the vertical axis. Has been. For example, at x = 45 degrees, it is shown that a light beam having an emission angle θ = 60 degrees having a peak intensity is about 2x−ψ = 50 degrees. In the process of calculating the result of FIG. 6, it is assumed that there is no light loss due to incidence into the light guide sheet 4 and refraction and total reflection. In the result of FIG. 9, the peak intensity of the radiation angle distribution of the light emitting element 3 can be set to an angle of 45.6 ° or more at which the value of the angle x is between 40 degrees and 45 degrees and totally reflected on the light emitting surface. I understand. That is, most of the light intensity in the vicinity of the peak intensity is totally reflected and introduced into the light guide sheet 4 and propagated in the lateral direction, and the backlight light is efficiently expanded in the plane of the light guide sheet 4. Means. As a result, the angle x half the tip angle of the V-shaped groove and the refractive index n of the light guide sheet so as to satisfy the relationship of 2x−sin ⁻¹ (sin θ / n) ≧ sin ⁻¹ (1 / n). And by adjusting and setting the radiation angle θ that becomes the peak of the light emitting element 3, it can be efficiently converted into laterally propagated light.

Further, regarding the light emitted from the side wall of the lens unit 20 and emitted from the light emitting diode 18, the refraction angle ψ after entering the light guide sheet 4 from the lens unit 20 is estimated as 90−sin ⁻¹ (sin (90− θ) / n). In this case, the emission angle θ of the light emitted from the light emitting diode 18 and the refraction angle ψ after entering the light guide sheet 4 are not based on the direction perpendicular to the side wall of the lens unit 20. Similarly to the above, the normal direction of the printed circuit board 22 is used as a reference. The light emitted from the side wall of the lens portion 20 of the light emitting element 3 is incident on the inner side wall of the light guide sheet 4 through the air layer as shown in FIG. Here, when the emission angle θ from the side wall of the lens unit 20 is plotted on the horizontal axis and the refraction angle 90-sin ⁻¹ (sin (90−θ) / n) is plotted on the vertical axis, FIG. become that way. As a result, the light emitted from the side wall of the lens unit 20 is larger than the total reflection angle of the light guide sheet 4 at most of the emission angles, and is totally reflected on the light emitting surface of the light guide sheet 4 and the back surface thereof. It can be seen that the light component propagates. The air layer interposed between the light guide sheet 4 and the light emitting element 3 only needs to be provided at least above the light emitting element 3, and the side portion of the light emitting element 3 is in contact with the light guide sheet 4. Also good.

  Further, the outer side surface of the light guide sheet 4 is preferably formed to be inclined in an inverted trapezoidal shape so as to spread toward the light emitting surface side, and is particularly preferably formed to be inclined at 45 degrees. When the side surface is not inclined and is formed substantially perpendicular to the light emitting surface, the light guided in the light guide sheet 4 substantially parallel to the light emitting surface is emitted from the side surface. However, when the side surface is inclined at 45 degrees, total reflection tends to occur. The light guided substantially parallel to the light emitting surface is reflected by the white reflective sheet 23 and the light emitting surface, enters the dot pattern formed on the light emitting surface, is emitted from the light emitting surface, and the light emission efficiency on the light emitting surface. Will improve.

  The white reflective sheet 23 is provided as a reflecting means on the surface opposite to the light emitting surface of the light guide sheet 4, and the white reflective sheet 23 further diffuses and reflects the incident light in a random direction. It is desirable to be a means. The light emitted from the light emitting element 3 is reflected by the concave portion of the light guide sheet 4 and propagated in the lateral direction, and the light propagated in the lateral direction enters the diffuse reflection means and is reflected in a random direction. . Since the light guided in the lateral direction is diffused and reflected in a random direction, the light is easily spread uniformly from the concave portion of the light guide sheet 4. And the dot pattern that becomes the emitting means for emitting light from the light emitting surface is densely distributed as it goes away from the recess, so that the guided light tends to spread in the lateral direction near the recess and in the part far from the recess The light is easily emitted, and the optical uniformity of the light emitting surface is improved. In addition, as shown in FIG. 11, the shape of the recessed part provided in the light guide sheet 4 is not a groove shape having a V-shaped inner surface, but the cross section is an arc shape and the center portion is a pan bottom shape. It may be a semi-cylindrical groove shape formed linearly in the direction. In this case, the peak position may be adjusted so that the radiation angle distribution of the light-emitting element 3 is suitable for the concave portion having a semi-cylindrical groove shape, or the emission angle θ = 0 degrees of the light-emitting element 3. You may make it the relative intensity | strength of a direction become still weaker than 0.5. As long as the light emitted from the light emitting element 3 is totally reflected and can be expanded in the lateral direction to be propagated light, other shapes, for example, a shape having a curved cross section may be used. .

  The light emitting surface of the light guide sheet 4 is provided with a shape for emitting the guided light so that the propagation light can be taken out little by little by changing the pattern density. FIG. 12 is a diagram illustrating a state in which a dot pattern for emitting light is provided on the light emitting surface of the light guide sheet 4 according to the present embodiment so as to become denser as the distance from the concave portion increases. On the upper surface side of the light guide sheet 4, the density of the dot pattern increases as the distance from the light guide sheet 4 increases. FIG. 13 is a modification of the light guide sheet 4 according to the present embodiment, and shows a state in which a line-shaped pattern for emitting light is provided on the light emitting surface so as to become denser as the distance from the concave portion increases. FIG. On the upper surface side of the light guide sheet 4, a line-shaped pattern formed in a groove shape having a triangular cross section for emitting light is provided, and as the distance from the light emitting element 3 propagates, The density of the groove-shaped pattern having a triangular cross section is increased. These dot-like or line-like patterns are formed by planting a scattering material composed of fine particles of nano to micron order on the light guide sheet 4 by screen printing. It is assumed that a material having a refractive index lower than that of the light guide sheet 4 is used for the dot pattern, such as silica and alumina. When the propagating light enters these dot patterns, a part of the propagating light is scattered upward and emitted. In the propagation direction of the light guide sheet 4, the density and size of the shape pattern are adjusted so that the intensity of the light component emitted upward is substantially uniform. The dot pattern as described above may be formed on the surface opposite to the light emitting surface, and light guided by irregular reflection by the dot pattern is emitted from the light emitting surface.

  Next, corresponding to the shape of the lens unit 20 shown in FIG. 6, the light emitting element 3 is arranged on the printed circuit board 22 on which the white reflective sheet is mounted as shown in FIG. On the other hand, the light guide sheet 4 having triangular prism-shaped concave portions and dot patterns whose centers are aligned is formed on the printed circuit board 22. Here, the dot pattern is arranged so as to be line symmetric with respect to the center line of the light emitting element 3. FIG. 14 is a diagram illustrating an example of a state in which dot patterns on the light emitting surface of the light guide sheet 4 according to the present embodiment are arranged, and the dot patterns are configured in a line. At a distance close to the light emitting element 3, the interval between the dot patterns arranged in a line is large, and the distance is set narrower as the distance from the light emitting element 3 increases.

  Further, as shown in FIG. 15, the region corresponding to the area control is configured to correspond to one light guide sheet 4, and a plurality of light guide sheets 4 are arranged in parallel and spread on the backlight support housing 12. Arrange. As shown in the figure, the light emitting elements 3 arranged in the backlight are controlled to emit light according to the displayed image, and one light guide sheet 4 is provided for each light emitting element 3. Each light emitting surface of the light guide sheet 4 corresponds to an area as a unit in which light emission of the backlight is controlled in the liquid crystal display device. By providing the light guide sheet 4 corresponding to each area that is a unit in which light emission is controlled, it is possible to suppress the irradiation region from expanding in a halo shape outside the area. Therefore, when the backlight is area-controlled, the boundary is clear and the contrast is improved between the area where light is irradiated and the area where light is not irradiated.

  Here, in the light guide sheet 4 in the present embodiment, as shown in FIG. 15, the light intensity increases mainly in the left-right direction, and a two-dimensional surface light source composed of light rays 28 irradiating anisotropically is formed. Has been.

  In the present embodiment, as described above, a backlight having a thin two-dimensional surface light source made of the light guide sheet 4 can be manufactured, and the entire liquid crystal display device can be thinned. Furthermore, a backlight having high uniformity in luminance and chromaticity can be manufactured by light irradiation that has been propagated through multiple reflections in the light guide sheet 4. In addition, a region corresponding to area control can be configured by the amount of the backlight divided by the plurality of light guide sheets 4, and light emission by the light emitting element 3 is controlled independently corresponding to the area, thereby reducing power consumption. Can be reduced.

  Accordingly, in the present embodiment, in the liquid crystal display device, backlight with high contrast in the irradiation area can be set, and a backlight with high light utilization efficiency and low power consumption can be provided. As its application, it is applied to a liquid crystal display device for a large television, a liquid crystal display device for a medium-sized personal computer or an in-vehicle car navigation system.

  Note that the liquid crystal display device according to the present embodiment employs area control in which a region in which light is emitted from the backlight to the liquid crystal panel is controlled according to the image to be displayed, but may not be employed. Needless to say, the optical uniformity is improved by the configuration of the light emitting element and the light guide member as described above.

  In the liquid crystal display device according to the present embodiment, the light guide sheet 4 is disposed so as to cover and cover one light emitting element 3. For example, all light emitting elements or all light emitting elements are disposed. A light guide member may be provided so as to be common to the plurality of light emitting elements 3 of the elements 3. In this case, a common light guide plate may be provided as a light guide member on the upper side of all the light emitting elements 3 mounted using the backlight support housing 12 as a substrate, or the arranged light emitting elements 3. A common light guide plate may be provided as a light guide member for each row. Further, in such a case, area control may be employed in the liquid crystal display device, and a light guide member is provided across a plurality of areas, and the boundary that is the boundary of the area is made clear. Such means may be provided separately.

  In addition, the light emitting element 3 concerning this embodiment is a light source which has a bimodal peak as shown in FIG. 4, By combining with the light guide sheet 4 which has the above recessed parts and a dot pattern, it is. It is preferable because optical uniformity can be improved. However, even if the peak of the light emitting element 3 does not have bimodality and has a peak in the direction where the emission angle is 0 degree, the light from the light emitting element 3 spreads from the concave portion of the light guide sheet 4. And the optical uniformity is improved. Note that the direction in which the emission angle is 0 degree corresponds to the direction of the optical axis in the light emitting element 3, and the direction of the optical axis is a direction that is substantially perpendicular to the liquid crystal panel.

[Embodiment 2]
Next, Embodiment 2 according to the present invention will be described with reference to FIGS. FIG. 16 is a diagram illustrating a cross-sectional state of the light guide sheet 4 and the light emitting element 3 according to the second embodiment. FIG. 17 illustrates the light guide sheet 4 and the light emitting elements 29 to 31 according to the second embodiment. FIG. As shown in FIG. 16 showing a cross-sectional configuration and FIG. 17 showing a planar configuration, light sources of three primary colors RGB of a red light emitting element 29, a green light emitting element 30, and a blue light emitting element 31 are applied to the light emitting element 3. Here, each of the light emitting elements 29 to 31 has a square shape and a light emission distribution having an isotropic radiation angle distribution, and the resin for sealing the light emitting diode 18 in each of the light emitting elements 29 to 31 is transparent. It is made of resin. That is, in the second embodiment, light emitting elements of a plurality of types of light emission colors for generating white are arranged side by side along a groove that forms a recess in the light guide sheet 4, and the first embodiment emits white light. Although different in that the light emitting element 3 is provided along a groove that forms the concave portion, the other points are substantially the same, and thus description thereof is omitted.

  FIG. 18 is a diagram illustrating the top surface of the light guide sheet 4 and the light emitting element 3 according to the modification of the second embodiment. FIG. 19 illustrates the light guide sheet 4 and the light emission according to the modification of the second embodiment. FIG. 11 is a diagram showing a state in which the elements 3 are arranged on the backlight support housing 12 while being arranged. The light emitting elements 32 to 34 of the three primary colors RGB may have a rectangular shape as shown in the cross-sectional configuration of FIG. 18 and the top surface configuration of FIG. As shown in FIGS. 18 and 19, a light source of three primary colors RGB, which is a red light emitting element 32, a green light emitting element 33, and a blue light emitting element 34, is applied. As shown in FIGS. 18 and 19, the longitudinal direction of the rectangular light emitting elements 32 to 34 is provided along the groove direction of the V-shaped groove-shaped recess provided in the light guide sheet 4. The dot patterns arranged densely with distance from the concave portion of the light guide sheet 4 are arranged in a line so as to be arranged in parallel along the concave portion, and in a line shape along the longitudinal side surfaces of the light emitting elements 32 to 34. Will be placed. By arranging in this way, high light intensity emitted from the side surfaces in the longitudinal direction of the light emitting elements 32 to 34 is propagated to the light guide sheet 4, and from the left and right directions rather than the vertical direction of the light guide sheet 4 in FIG. The light beam 28 having high light intensity and anisotropic light irradiation can be extracted as backlight light. As described above, by applying the rectangular light emitting elements 32 to 34 and using the light guide sheet 4 shown in FIG. 18, a two-dimensional planar light source having high anisotropy in the left-right direction is formed. By using such a two-dimensional planar light source having high anisotropy in the left-right direction, high contrast is generated at the boundary in the left-right direction during area control.

  For example, as illustrated in FIG. 19, each light emitting element in the second embodiment is disposed such that the light emission colors complement each other, which are disposed in the recesses of the light guide sheet 4 adjacent to each other. Specifically, the light emitting elements in Embodiment 2 are regularly arranged so that light emitting elements of different emission colors are adjacent to each other along the vertical direction (groove direction), and in the lateral direction (with respect to the grooves). The light emitting elements arranged in the vertical direction are also regularly arranged so that light emitting elements having different emission colors are adjacent to each other.

  In the second embodiment, a light source of each of the three primary colors RGB is mounted, and a white light source with adjusted luminance and chromaticity can be obtained by propagating through the light guide sheet 4 and mixing the colors. The light emitting elements of the three primary colors RGB can be used as a backlight as a primary color light source by controlling them independently. Further, similarly to the first embodiment, a backlight having a thin two-dimensional surface light source made of the light guide sheet 4 can be manufactured, and the entire liquid crystal display device can be thinned. Furthermore, the backlight which has the uniformity with high brightness | luminance and chromaticity can be achieved by the light irradiation which carried out the multi-reflection in the light guide sheet 4, and propagated. In addition, the area corresponding to the area control can be configured as much as the backlight is divided by the plurality of light guide sheets 4 provided, and the light emission by the light emitting element 3 is independently controlled corresponding to the area. Can be reduced.

  Accordingly, in the second embodiment, in the liquid crystal display device, backlight light having a high contrast in the irradiation area can be set, and a backlight light source and an optical system with high light utilization efficiency and low power consumption can be provided. Applications include liquid crystal panel display devices for large televisions, medium-sized personal computers, and in-vehicle car navigation liquid crystal panel display devices.

[Embodiment 3]
In the first and second embodiments, the light emitting element 3 and the light guide sheet 4 having a planar configuration as shown in FIGS. 5 and 14 are used. In the third embodiment, the light emitting element 3 and the light guide sheet 4 are shown in FIGS. Although the light-emitting element 3 and the light guide sheet 4 having such a planar configuration are different, the points other than the points regarding the light-emitting element 3 and the light guide sheet 4 are substantially the same, and thus description thereof is omitted. To do.

  As shown in FIG. 20, the concave portion of the lens portion 20 of the light emitting element 3 is formed in a spot shape so as to be located immediately above the light emitting diode 18. The concave portion is formed in a conical shape at the center of the light emitting diode 18. Since the lens portion 20 in the light emitting element 3 has a conical concave shape, an optical distribution that isotropically expands the luminous flux from the light emitting diode 18 is obtained. Therefore, the radiation angle distribution in the first and second embodiments has a bimodal peak as shown in FIGS. 4 and 6, but the light-emitting element 3 in the third embodiment has a ring-shaped peak. In other words, the ring-shaped peak is substantially point-symmetric with respect to the optical axis direction of the light-emitting element 3 having an emission angle of 0 degree.

  When the shape pattern of the light guide sheet 4 is viewed from the top, the light emitting element 3 is formed on the printed circuit board 22 on which the white reflective sheet 23 is mounted, as shown in FIG. 21, corresponding to the lens unit 20 shown in FIG. Be placed. The light guide sheet 4 is formed with a concave portion having an inner surface whose center is aligned with the light emitting element 3 and whose cross section is tapered in a V shape. The light guide sheet 4 according to the third embodiment has a conical concave portion at a position directly above the light emitting element 3 and has a dot pattern that becomes denser as the distance from the concave portion increases. The substrate is configured to cover the light emitting element 3 so as to cover the light emitting element 3. Here, the dot pattern is symmetric with respect to the center of the light emitting diode 18 in the light emitting element 3, and as an example, the dot pattern is arranged in a square as shown in FIG. Further, the interval between the dot pattern and the dot pattern arranged in a quadrangular shape becomes narrower as the distance from the light emitting element 3 increases, and the distance becomes wider at a distance closer to the light emitting element 3, and as the distance from the light emitting element 3 increases. The interval is set narrow. In the third embodiment, the dot patterns serving as the emitting means for emitting the light guided in the light guide sheet 4 to the light emitting surface are arranged in a quadrangular shape, but concentrically around the light emitting diode 18. It may be distributed.

  In addition, as shown in FIG. 22, one light guide sheet 4 is configured to correspond to an area corresponding to area control, and a plurality of light guide sheets 4 are arranged in parallel, on the backlight support housing 12. Laid down. Thus, an area-controlled backlight corresponding to the light emitting element 3 is configured. In this way, a two-dimensional surface light source that emits a light beam 28 that isotropically propagates in the light guide sheet 4 is formed.

  In the third embodiment, the concave portion is formed in a conically tapered shape. However, for example, the concave portion may be formed to have a tapered inner surface by a curved surface such as a spherical shape. 3 is adjusted so as to be suitable for the concave portion, or the relative intensity of the light emitting element 3 in the direction of the emission angle θ = 0 ° is further weaker than 0.5. May be. Further, when the concave portion of the light guide sheet 4 is formed in a conical shape having a V-shaped cross section as in the third embodiment, or is formed in a triangular groove shape as in the first or second embodiment. In some cases, the light emitting element 3 may be adjusted so as to increase the amount of light emitted in the optical axis direction by forming a flat tip at the center.

  The present invention can be applied as an optical system and a backlight light source in a liquid crystal display device for a large-sized liquid crystal television, and a small and medium-sized liquid crystal display device such as a mobile phone or a personal computer. Further, it goes without saying that the contents are valid even when applied as an optical system and a light source of a lighting device. Although the present contents have been described using the light emitting diode element, it is needless to say that the contents are valid even when the semiconductor laser diode element is applied as an excitation light source of a phosphor material.

  DESCRIPTION OF SYMBOLS 1 Backlight housing | casing, 2 Printed circuit board which has white reflective sheet, 3 Light emitting diode package light source (light emitting element), 4 Light guide sheet, 5 Diffuser plate, 6 Diffuser sheet, 7 Prism sheet, 8 Polarized reflective sheet, 9 Lower polarized light Plate, 10 Liquid crystal sealing glass substrate with thin film transistor and color filter 11 Upper polarizing plate, 12 Backlight support housing, 13 Area control compatible split light source consisting of light emitting element and light guide sheet, 14 drive circuit, 15 resin molding material Base material composed of ceramic material, 16 wiring, 17 die bond material, 18 light emitting diode, 19 Au wire, 20 lens portion, 21 lens portion having triangular prism-shaped recess, 22 printed circuit board, 23 white reflective sheet, 26 dot pattern , 27 triangular groove pattern, 28 rays, 29 red square LED package source, 30 a green square LED package source, 31 blue square LED package source, 32 red rectangular LED package source, 33 green rectangular LED package source, 34 blue rectangular LED package sources.

Claims (17)

In a liquid crystal display device including a liquid crystal panel and a backlight,
The backlight includes a light emitting element disposed below the liquid crystal panel and emitting light toward the liquid crystal panel, and a light guide member disposed above the light emitting element and below the liquid crystal panel. Have
The light guide member has a light emitting surface on the liquid crystal panel side where light from the light emitting element is guided to emit light in a planar shape,
On the light emitting surface, a concave portion is formed immediately above the light emitting element, and a dot-like or line-like pattern for emitting light is distributed so as to become dense as it leaves the concave portion,
The recess is formed with an inner surface that is inclined so as to taper in the depth direction of the recess,
The concave portion is formed so that a cross section is V-shaped by the inner surface inclined at an inclination angle α with respect to the light emitting surface at 35 ° ≦ α ≦ 55 °,
The concave portion is formed so as to further expand than the portion where the light emitting element emits light, and the central portion of the concave portion is arranged so as to be aligned with the center of the light emitting portion,
The light-emitting element includes a light-emitting diode and a lens portion that covers the light-emitting diode from above, and a concave portion is formed in the lens portion at a position directly above the light-emitting diode,
An air layer is interposed between the lens unit and the light guide member, and the light guide member covers the lens unit through the air layer.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 1,
The concave portion of the light guide member is formed in a V-shaped cross section by the inner surface inclined at an inclination angle α with respect to the light emitting surface at 45 degrees ≦ α ≦ 50 degrees.
A liquid crystal display device characterized by the above. In a liquid crystal display device including a liquid crystal panel and a backlight,
The backlight includes a light emitting element disposed below the liquid crystal panel and emitting light toward the liquid crystal panel, and a light guide member disposed above the light emitting element and below the liquid crystal panel. Have
The light guide member has a light emitting surface on the liquid crystal panel side where light from the light emitting element is guided to emit light in a planar shape,
On the light emitting surface, a concave portion is formed immediately above the light emitting element, and a dot-like or line-like pattern for emitting light is distributed so as to become dense as it leaves the concave portion,
The recess is formed with an inner surface that is inclined so as to taper in the depth direction of the recess,
The concave portion is formed including a first inner surface that forms a bottom portion located at a central portion of the concave portion, and a second inner surface that forms a side surface portion from the bottom portion to the edge of the concave portion,
The first inner surface and the second inner surface have different inclination angles with respect to the light emitting surface, and the inclination angle of the first inner surface is steeper than the inclination angle of the second inner surface,
The first inner surface is disposed so as to be aligned with the center of the light emitting portion of the light emitting element and is substantially overlapped with the light emitting portion, and the second inner surface is around the first inner surface. Formed so as to further spread from the light emitting part ,
The light-emitting element includes a light-emitting diode and a lens portion that covers the light-emitting diode from above, and a concave portion is formed in the lens portion at a position directly above the light-emitting diode,
An air layer is interposed between the lens unit and the light guide member, and the light guide member covers the lens unit through the air layer.
A liquid crystal display device characterized by the above. In the liquid crystal display device according to any one of claims 1 to 3,
The concave portion of the light guide member is formed in a groove shape formed linearly in one direction,
The dot-shaped or line-shaped pattern is distributed so as to become denser as the distance from the concave portion of the light guide member increases.
A liquid crystal display device characterized by the above. In the liquid crystal display device according to any one of claims 1 to 3,
The concave portion of the light guide member is formed in a conical shape,
The dot-like or line-like pattern is distributed concentrically so as to become denser as the distance from the concave portion of the light guide member increases.
A liquid crystal display device characterized by the above. In a liquid crystal display device including a liquid crystal panel and a backlight,
The backlight includes a light emitting element disposed below the liquid crystal panel and emitting light toward the liquid crystal panel, and a light guide member disposed above the light emitting element and below the liquid crystal panel. Have
The light guide member has a light emitting surface on the liquid crystal panel side where light from the light emitting element is guided to emit light in a planar shape,
On the light emitting surface, a concave portion is formed immediately above the light emitting element, and a dot-like or line-like pattern for emitting light is distributed so as to become dense as it leaves the concave portion,
The recess is formed with an inner surface that is inclined so as to taper in the depth direction of the recess,
The inner surface is formed to be curved in an arc shape,
The concave portion is a groove shape that is linear in one direction, and is formed to be tapered by the inner surface curved in an arc shape,
The concave portion is formed so as to further expand than the portion where the light emitting element emits light, and the central portion of the concave portion is arranged so as to be aligned with the center of the light emitting portion,
The dot-shaped or line-shaped pattern is distributed in parallel to the concave portions that are linear, so as to become denser as the distance from the concave portions increases .
The light-emitting element includes a light-emitting diode and a lens portion that covers the light-emitting diode from above, and a concave portion is formed in the lens portion at a position directly above the light-emitting diode,
An air layer is interposed between the lens unit and the light guide member, and the light guide member covers the lens unit through the air layer.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 1,
The central portion of the concave portion of the light guide member is formed flat.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 4 and 6,
Below the concave portion of the light guide member, a plurality of light emitting elements that emit light of different emission colors to generate white are arranged along the groove shape that is linear,
The plurality of light emitting elements arranged along the groove shape and the light emitting elements arranged adjacent to each other in a direction different from the groove part are arranged so that emission colors are complemented to each other.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 , 3, and 6 ,
The light guide member has an incident portion for allowing light from the light emitting element to be incident on a back surface which is a back side with respect to the light emitting surface,
On the back surface, a diffuse reflection means is provided in a part away from the incident part,
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1 , 3, and 6 ,
The light guide member has an incident portion for allowing light from the light emitting element to be incident on a back surface which is a back side with respect to the light emitting surface,
On the back surface, a dot-like or line-like pattern for reflecting light to the light emitting surface to emit light is distributed so as to become dense as it leaves the incident portion.
A liquid crystal display device characterized by the above. A liquid crystal display device according to any one of claims 1 to 10,
The light emitting element has an optical axis in a direction substantially perpendicular to the liquid crystal panel,
The emission luminance of the light emitting element is distributed symmetrically with respect to the optical axis and has a peak in a direction inclined with respect to the optical axis.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 11,
The lens portion has a concave lens-shaped exit surface for emitting light toward the light guide member side, and the concave portion of the lens portion has a V-shaped cross section that is symmetric with respect to the optical axis. Formed
The concave portion of the light guide member has a shape corresponding to the shape of the concave portion of the lens portion.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 4 and 6,
The emission luminance of the light emitting element is distributed symmetrically with respect to the direction in which the concave portion is formed in a linear groove shape, and has a bimodal peak.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 5,
The light emitting element has an optical axis in a direction substantially perpendicular to the liquid crystal panel,
The emission luminance of the light-emitting element is distributed point-symmetrically with respect to the optical axis and has a ring-shaped peak.
A liquid crystal display device characterized by the above. The liquid crystal display device according to any one of claims 1, 3, and 6,
The backlight includes the light guide member provided for each of the one or more light emitting elements at a plurality of locations,
Each of the light guide members provided in a plurality of places constitutes a region corresponding to area control, and is disposed apart from the adjacent light guide members.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 15,
In the light guide member, a side surface of the light guide member is inclined so that the light emitting surface is wider than a surface on which the light emitting element is disposed.
A liquid crystal display device characterized by the above. The liquid crystal display device according to claim 15,
The backlight is
The one or more light emitting elements have a substrate arranged in a plurality of locations ,
The light guide member is disposed on the substrate so as to cover the upper side from the side of the one or more light emitting elements,
On the surface where the light guide member is in contact with the substrate, diffuse reflection means for diffusing and reflecting light from the one or more light emitting elements is disposed.
A liquid crystal display device characterized by the above.

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