JP2010266544A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with high display quality. <P>SOLUTION: The liquid crystal display device includes: a liquid crystal display panel 2 having a display part 6; and a lighting unit 15 illuminating the display part 6. The lighting unit 15 includes a light source 21, and a light guide body 22 having: an incident face 22C1, on which light emitted from the light source 21 is incident; and a recess part 22H recessed from the incidence face 22C1 and extended in the direction D2 substantially orthogonally crossing the thickness direction D1 of light guide body 22 on the incidence face 22C1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device.

  A transmissive or transflective liquid crystal display device includes a transmissive or transflective liquid crystal display panel and an illumination unit (that is, a backlight) disposed on the back side of the liquid crystal display panel.

  Such a liquid crystal display device includes a light guide having a main plane facing the liquid crystal display panel and a side surface substantially orthogonal to the main plane, and a light source disposed along the side surface of the light guide. The equipped lighting unit has been put into practical use. In such an illumination unit, for example, a light emitting diode or a cold cathode tube is used as a light source.

  For example, Patent Document 1 discloses a sidelight type surface light source device that employs a light emitting diode as a light source. In Patent Document 1, since the light emitted from the light emitting diode is highly linear, both end surfaces of the incident surface of the light guide are distributed for the purpose of uniformly distributing the incident light to the corners of the light guide. Of the sidelight type surface light source device in which only the both end regions of the sidelight surface light source device are provided with protrusions that are larger as they are separated from the central region, project in a planar shape with respect to the outside, and have a substantially semicircular cross section in a direction perpendicular to the incident surface. A configuration is disclosed.

JP 2008-103162 A

  However, in such a configuration, when a light emitting diode that emits dispersed light, for example, a light emitting diode with a lens, is used as a light source, the emitted light emitted from the light source may be dispersed in the thickness direction of the light guide. . As a result, the amount of light emitted from the light source may be used in a region near the light source, and the amount of light may be insufficient in a region far from the light source. As a result, uniform light may not be emitted from the emission surface of the light guide. In a liquid crystal display device equipped with such an illumination unit having a light guide, display quality may be deteriorated.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a liquid crystal display device with good display quality.

  A liquid crystal display device according to an aspect of the present invention includes a liquid crystal display panel having a display unit, and an illumination unit that illuminates the display unit, and the illumination unit receives a light source and light emitted from the light source. And a light guide having a recess recessed from the incident surface and extending in a direction substantially orthogonal to the thickness direction of the light guide on the incident surface.

  According to the present invention, a liquid crystal display device with good display quality can be provided.

FIG. 1 is a plan view schematically showing a configuration example of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the structure of the liquid crystal display device shown in FIG. FIG. 3 is a perspective view schematically showing a structural example of the light guide of the illumination unit shown in FIGS. 1 and 2. FIG. 4 is a cross-sectional view showing a partial structure of the concave portion of the light guide shown in FIG. FIG. 5 is a diagram for explaining the effect of the liquid crystal display device including the light guide body having the concave portion shown in FIG. FIG. 6 is a cross-sectional view showing a part of another structure of the concave portion of the light guide. FIG. 7 is a cross-sectional view showing a part of another structure of the concave portion of the light guide. FIG. 8 is a cross-sectional view showing a part of another structure of the concave portion of the light guide. FIG. 9 is a cross-sectional view showing a part of another structure of the concave portion of the light guide. FIG. 10 is a cross-sectional view showing a part of another structure of the concave portion of the light guide. FIG. 11 is a cross-sectional view showing a part of another structure of the concave portion of the light guide. FIG. 12 is a cross-sectional view showing a part of another structure of the concave portion of the light guide.

  Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Here, a transmissive liquid crystal display device that selectively transmits light from the illumination unit and displays an image will be described. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted.

  As shown in FIG. 1, the liquid crystal display device 1 includes a substantially rectangular flat liquid crystal display panel 2 having a display unit 6, an illumination unit 15 that illuminates the display unit 6 of the liquid crystal display panel 2, and an illumination unit 15. ing.

  The liquid crystal display panel 2 includes a substantially rectangular array substrate 3 and a counter substrate 4, and a liquid crystal layer 5 sealed between the array substrate 3 and the counter substrate 4. The array substrate 3 and the counter substrate 4 are bonded together via a sealing material (not shown) disposed so as to surround the display unit 6.

  In the display unit 6, the array substrate 3 includes a plurality of scanning lines Y (1, 2,...), A plurality of signal lines X (1, 2,...), A switching element 7 disposed in each pixel PX, and each pixel PX. The pixel electrode 8 connected to the switching element 7 is provided. The pixel electrode 8 is formed of a light-transmitting conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

  Each scanning line Y extends along the row direction of the pixel PX. Each signal line X extends along the column direction of the pixels PX so as to intersect with each scanning line Y through an insulating layer (not shown). Each switching element 7 is disposed in a region including an intersection of the scanning line Y and the signal line X.

  The switching element 7 is composed of, for example, a thin film transistor (TFT) including a semiconductor layer formed of amorphous silicon, polysilicon, or the like. The gate electrode 7G of the switching element 7 is electrically connected to the corresponding scanning line Y (or formed integrally with the scanning line). The source electrode 7S of the switching element 7 is electrically connected to the corresponding signal line X (or formed integrally with the signal line). The drain electrode 7D of the switching element 7 is electrically connected to the pixel electrode 8 of the corresponding pixel PX.

  The common electrode 9 for applying a voltage to the liquid crystal layer 5 due to a potential difference with the pixel electrode 8 may be provided on the array substrate 3 or on the counter substrate 4. That is, in the horizontal electric field mode mainly using the horizontal electric field (electric field substantially parallel to the main surface facing the liquid crystal layer 5 of the substrate), the array substrate 3 is electrically insulated from the pixel electrode 8 and is not connected to the pixel electrode 8. Opposing common electrodes 9 are provided. In the vertical electric field mode that mainly uses the vertical electric field (electric field substantially perpendicular to the main surface facing the liquid crystal layer 5 of the substrate), the counter substrate 4 has the common electrode 9 that faces the pixel electrode 8 through the liquid crystal layer 5. It has. Similar to the pixel electrode 8, the common electrode 9 is formed of a light-transmitting conductive material.

  The surfaces of the array substrate 3 and the counter substrate 4 that are in contact with the liquid crystal layer 5 are each covered with an alignment film (not shown). The array substrate 3 and the counter substrate 4 are bonded to each other with the alignment films facing each other via spacers (not shown). At this time, a predetermined gap is formed between the array substrate 3 and the counter substrate 4 by a spacer. The liquid crystal layer 5 is formed of a liquid crystal composition sealed in the gap between the array substrate 3 and the counter substrate 4.

  In the liquid crystal display panel 2, optical elements OD1 and OD2 are provided on the outer surface of the array substrate 3 and the outer surface of the counter substrate 4, respectively. These optical elements OD1 and OD2 include polarizing plates whose polarization directions are set in accordance with the characteristics of the liquid crystal layer 5. Further, the optical elements OD1 and OD2 may include a retardation plate as necessary.

  In the color display type liquid crystal display device, the liquid crystal display panel 2 includes a plurality of types of pixels, for example, a red pixel that displays red (R), a green pixel that displays green (G), and a blue (B ) Is displayed. That is, the red pixel includes a red color filter that transmits light having a red main wavelength. The green pixel includes a green color filter that transmits light having a green dominant wavelength. The blue pixel includes a blue color filter that transmits light having a blue main wavelength. These color filters are arranged on the main surface of the array substrate 3 or the counter substrate 4.

  The liquid crystal display device 1 includes a bezel cover 11 having a rectangular frame shape. The bezel cover 11 includes a rectangular window portion 11A that exposes the display portion 6 of the liquid crystal display panel 2 and a rectangular frame-shaped main body portion 11B that defines the window portion 11A.

  The liquid crystal display panel 2 configured as described above is sandwiched between the illumination unit 15 and the bezel cover 11. At this time, the illumination unit 15 is arranged with its surface facing the back side of the liquid crystal display panel 2 (that is, the array substrate 3 side), and illuminates the liquid crystal display panel 2 from the back side.

  As shown in FIG. 2, the illumination unit 15 includes a light source 21, a light guide 22, a wiring board 23, a frame 24, an optical sheet 26, and the like.

  Here, the light source 21 includes a light emitting diode (LED) 21A. The light emitting diode 21A is, for example, a light emitting diode with a lens. The light emitted from the light emitting diode 21A emits light with a predetermined divergence angle.

  The light guide 22 has a function of guiding emitted light from the light emitting diode 21 </ b> A toward the liquid crystal display panel 2. The light guide 22 is formed of a light-transmissive resin material such as an acrylic resin or a polycarbonate resin.

  The light guide 22 has a thin portion at one end and a wedge portion having a thick portion at the other end facing the thin portion, and a flat plate having a substantially uniform thickness over the whole. However, in this embodiment, a rectangular flat plate type is adopted.

  The light guide 22 includes a rectangular first main plane 22A facing the liquid crystal display panel 2 side, a rectangular second main plane 22B facing the first main plane 22A, and the first main planes. It has four rectangular end faces 22C that connect 22A and the second main plane 22B. The one end surface 22C1 is an incident surface on which light emitted from the light source 21 enters. The first main plane 22 </ b> A is an emission surface that emits light toward the liquid crystal display panel 2.

  The frame 24 is mainly configured to hold the light guide 22. The frame 24 is made of a resin material.

  As shown in FIG. 3, a plurality of light emitting diodes 21 </ b> A are mounted in a line at a predetermined interval on the wiring board 23 for the light source 21. The wiring substrate 23 is affixed to the light guide 22 so that the light emitting surface of the light emitted from the light emitting diode 21A faces the incident surface 22C1 of the light guide 22. A connector 23 </ b> A for supplying a signal to the light source 21 is connected to the wiring board 23.

  The optical sheet 26 is disposed between the liquid crystal display panel 2 and the optical sheet 26 </ b> A disposed between the light exit surface 22 </ b> A of the light guide 22 and the back cover 25 and the second main plane 22 </ b> B of the light guide 22. An optical sheet 26B is provided.

  The optical sheet 26 </ b> A is, for example, a condensing sheet or a diffusion sheet, and imparts predetermined optical characteristics to the light emitted from the light guide 22 and guides it to the liquid crystal display panel 2. The optical sheet 26 </ b> B is a reflection sheet, and reflects light leaking from the second main plane 22 </ b> B of the light guide 22 toward the light guide 22 again.

  The back cover 25 is disposed so as to face the back surface of the lighting unit 15. The back cover 25 is generally formed in a box shape and can accommodate the light source 21, the light guide 22, and the like.

  By the way, the light guide 22 has the recessed part 22H dented from the entrance plane 22C1. The recess 22H is recessed from the incident surface 22C1 toward the end surface 22C2 facing the incident surface 22C1.

  The concave portion 22H extends in parallel with a direction D2 substantially orthogonal to the thickness direction D1 of the light guide 22 on the incident surface 22C1. Here, the light guide 22 has a plurality of recesses 22H. The recesses 22 </ b> H are arranged in the thickness direction D <b> 1 of the light guide 22. Such a recess 22H is formed so as not to overlap the display unit 6 when the illumination unit 15 and the liquid crystal display panel 2 overlap.

  In the first embodiment, the recess 22H includes a plurality of side end faces 22T. Each side end face 22T has an angle θ1 formed with the incident face 22C1 larger than 90 degrees.

  In the example shown in FIG. 4, two side end surfaces 22T (first side end surface 22T1 and second side end surface 22T2) are provided. The first side end surface 22T1 and the second side end surface 22T2 have an obtuse angle with the incident surface 22C1. The first side end face 22T1 and the second side end face 22T2 are connected. That is, the portion of the light guide 22 that faces the light source 21 has a shape in which a triangular prism is cut out.

  Specifically, the light guide 22 has a first recess 22H1, a second recess 22H2, and a third recess 22H3 in this order from the emission surface 22A side. The first side end surface 22T1 of the first recess 22H1 is connected to the incident surface 22C1 and the second side end surface 22T2 of the first recess 22H1. The second side end surface 22T2 of the first recess 22H1 is connected to the first side end surface 22T1 of the first recess 22H1 and the first side end surface 22T1 of the second recess 22H2.

  The first side end surface 22T1 of the second recess is connected to the second side end surface 22T2 of the first recess 22H1 and the second side end surface 22T2 of the second recess 22H2. The second side end surface 22T2 of the second recess 22H2 is connected to the first side end surface 22T1 of the second recess 22H2 and the first side end surface 22T1 of the third recess 22H3.

  In such a configuration, as shown in FIG. 5, the emitted light 21L emitted from the light source 21 has an angle θ1 formed by the first side end surface 22T1 and the second side end surface 22T2 of the recess 22H with the incident surface 22C1 from 90 degrees. Since it is large, the light is condensed by being refracted by the first side end surface 22T1 and the second side end surface 22T2 of the recess 22H.

  Accordingly, in the thickness direction D1 of the light guide 22, it is possible to suppress the emission light 21 </ b> L from being dispersed in the region near the light source 21 of the light guide 22, and the light amount is used only in the region near the light source 21. Can be suppressed. Thereby, the emitted light 21L from the light source 21 is guided to a region far from the light source 21 of the light guide 22, and the amount of light can be used even in a region far from the light source. That is, a region far from the light source 21 of the light guide 22 does not become darker than a region near the light source 21 of the light guide 22, and uniform light can be emitted from the light guide 22. Therefore, in the liquid crystal display device 1 on which the illumination unit 15 having such a light guide 22 is mounted, it is possible to prevent display quality from being deteriorated.

  In the example shown in FIG. 6, the first side end surface 22T1 of the first recess 22H1 is parallel to the incident surface 22C1. The first side end surface 22T1 is connected to the emission surface 22A and the second side end surface 22T2 of the first recess 22H1. Even in such a configuration, it is possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  In the example shown in FIG. 7, the recess 22H includes three side end surfaces 22T (first side end surface 22T1, second side end surface 22T2, and third side end surface 22T3). The first side end surface 22T1 and the third side end surface 22T3 have an obtuse angle with the incident surface 22C1. The second side end surface 22T2 is parallel to the incident surface 22C1. That is, the portion of the light guide 22 that faces the light source 21 has a shape in which the bottom surface is cut out of a trapezoidal quadrangular prism.

  Specifically, the first side end surface 22T1 of the recess 22H is connected to the incident surface 22C1 and the second side end surface 22T2. The second side end face 22T2 is connected to the first side end face 22T1 and the second side end face 22T3. The third side end surface 22T3 is connected to the second side end surface 22T2 and the incident surface 22C1. Even in such a configuration, it is possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  Here, an example in which the concave portion 22H includes two and three side end surfaces 22T has been described. However, the present invention is not limited to this example, and the same effect can be obtained even if the concave portion 22H includes a plurality of side end surfaces 22T. It is done. Moreover, although the example in which the several recessed part 22H was located in a line with the thickness direction D1 of the light guide 22 was demonstrated, it should just have at least 1 recessed part 22H.

  Next, a second embodiment will be described. In addition, about the structure similar to the liquid crystal display device which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the second embodiment, the recess 22H further includes a curved surface 22U in addition to the side end surface 22T. The curved surface 22U is connected to the incident surface 22C1 or the side end surface 22T. The surface 22UA in contact with the curved surface 22U has an angle θ2 formed with the incident surface 22C1 of 90 degrees or more or parallel to the incident surface 22C1.

  In the example illustrated in FIG. 8, the recess 22H includes two side end surfaces 22T (first side end surface 22T1 and second side end surface 22T2) and one curved surface 22U. Each of the first side end surface 22T1 and the second side end surface 22T2 has an obtuse angle θ1 formed with the incident surface 22C1. The surface 22UA1 in contact with the curved surface 22U has an obtuse angle θ2 formed with the incident surface 22C1. Further, the surface 22UA2 in contact with the curved surface 22U is parallel to the incident surface 22C1. Here, only the surfaces 22UA1 and 22UA2 that are in contact with the two curved surfaces 22U are illustrated, but the angle θ2 that the surface 22UA that is in contact with other points also forms with the incident surface 22C1 is 90 degrees or more or parallel to the incident surface 22C1.

  Specifically, the first side end surface 22T1 of the recess 22H is connected to the incident surface 22C1 and the curved surface 22U. The curved surface 22U is connected to the first side end face 22T1 and the second side end face 22T2. The second side end surface 22T2 is connected to the curved surface 22U and the incident surface 22C1.

  Even in such a configuration, the light emitted from the light source is condensed by being refracted by the first side end surface 22T1 and the second side end surface 22T2 of the recess 22H. Furthermore, the light emitted from the light source 21 is refracted by the curved surface 22U of the concave portion 22H because the angle θ2 formed by the surface 22UA in contact with the curved surface 22U and the incident surface 22C1 is 90 degrees or more or parallel to the incident surface 22C1. Focused. That is, in the thickness direction D1 of the light guide 22, it becomes possible to prevent the light emitted from the light source 21 from being dispersed, and the same effect as in the first embodiment can be obtained.

  In the example shown in FIG. 9, the recess 22H includes one side end face 22T and two curved surfaces 22U (first curved surfaces 22U1, 22U2). The side end face 22T is parallel to the incident face 22C1. Specifically, the first curved surface 22U1 of the recess 22H is connected to the incident surface 22C1 and the side end surface 22T of the recess 22H.

  The side end surface 22T of the recess 22H is connected to the first curved surface 22U1 and the second curved surface 22U2 of the recess 22H. The second curved surface 22U2 of the recess 22H is connected to the side end surface 22T and the incident surface 22C1. Even in such a configuration, it is possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  In the example shown in FIG. 9, the recess 22H closest to the first main plane 22A includes one side end face 22T1 and one curved face 22U. The side end face 22T is parallel to the incident face 22C1. The side end surface 22T is connected to the first main plane 22A and the curved surface 22U of the recess 22H.

  The curved surface 22U is connected to a first curved surface 22U1 of a recess adjacent to the side end surface. Even in such a configuration, it is possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  Here, an example in which the concave portion 22H includes two side end surfaces 22T and one and two curved surfaces 22U has been described. However, the present invention is not limited to this example, and the concave portion 22H has one or more side end surfaces 22T and 1T. The same effect can be obtained if two or more curved surfaces 22U are provided. Moreover, although the example in which the several recessed part 22H was located in a line with the thickness direction D1 of the light guide 22 was demonstrated, it should just have at least 1 recessed part 22H.

  Next, a third embodiment will be described. In addition, about the structure similar to the liquid crystal display device which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the third embodiment, the recess 22H includes at least one curved surface 22U. The surface 22UA in contact with the curved surface 22U has an angle θ2 formed with the incident surface 22C1 of 90 degrees or more or parallel to the incident surface 22C1.

  In the example shown in FIG. 10, the concave portion 22H includes one curved surface 22U. The curved surface 22U is connected to the incident surface 22C1. The surface 22UA1 in contact with the curved surface 22U has an obtuse angle θ2 formed with the incident surface 22C1. Further, the surface 22UA2 in contact with the curved surface 22U is parallel to the incident surface 22C1. Here, only the surfaces 22UA1 and 22UA2 that are in contact with the two curved surfaces 22U are illustrated, but the angle θ2 that the surface 22UA that is in contact with other points also forms with the incident surface 22C1 is 90 degrees or more or parallel to the incident surface 22C1.

  Even in such a configuration, the outgoing light from the light source 21 is refracted by the curved surface 22U of the recess 22H because the angle θ2 formed by the surface 22UA in contact with the curved surface 22U and the incident surface 22C1 is 90 degrees or more or parallel to the incident surface 21C. Is collected. That is, in the thickness direction D1 of the light guide 22, it becomes possible to prevent the light emitted from the light source 21 from being dispersed, and the same effect as in the first embodiment can be obtained.

  In addition, although the example in which the recessed part 22H was provided with one curved surface 22U was demonstrated here, the same effect will be acquired even if the recessed part 22H is provided with the some curved surface 22U. Moreover, although the example in which the several recessed part 22H was located in a line with the thickness direction D1 of the light guide 22 was demonstrated, it should just have at least 1 recessed part 22H.

  Next, a fourth embodiment will be described. In addition, about the structure similar to the liquid crystal display device which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the fourth embodiment, the light guide 22 has a first recess 22H1 and a second recess 22H2. In the example shown in FIG. 11, the width W1 of the light guide 22 in the thickness direction D1 of the first recess 22H1 is larger than the width W2 of the light guide 22 in the thickness direction D1 of the second recess 22H2. Even in such a configuration, it becomes possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  The height H1 of the first recess 22H in the direction D3 substantially perpendicular to the thickness direction D1 of the light guide 22 and the direction D2 substantially perpendicular to the thickness direction D1 of the light guide 22 is guided by the second recess 22H2. It is larger than the height H2 in the direction D3 substantially orthogonal to the thickness direction D1 of the light body 22. Even in such a configuration, it is possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  In addition, although the shape of the recessed part of 1st Embodiment was demonstrated to the example as a shape of the recessed part 22H here, the same effect is acquired even if the recessed part 22H is another shape not only in this example.

  Next, a fifth embodiment will be described. In addition, about the structure similar to the liquid crystal display device which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the fifth embodiment, as shown in FIG. 12, the light guide 22 includes a first recess 22H1, a second recess 22H2, a third recess 22H3, and a fourth recess 22H4. The first recess 22H1 is adjacent to the second recess 22H2. The third recess 22H3 is adjacent to the fourth recess 22H4. The distance L1 in the thickness direction D1 of the light guide 22 between the first recess 22H1 and the second recess 22H2 is in the thickness direction D1 of the light guide 22 between the third recess 22H3 and the fourth recess 22H4. It is smaller than the distance L2. Even in such a configuration, it becomes possible to prevent dispersion of light emitted from the light source 21 in the thickness direction D1 of the light guide 22, and the same effect as in the first embodiment can be obtained.

  In addition, although the shape of the recessed part of 1st Embodiment was demonstrated to the example as a shape of the recessed part 22H here, the same effect is acquired even if the recessed part 22H is another shape not only in this example.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  For example, even if the light guide 22 is combined with the recesses 22H in the first to third embodiments as the plurality of recesses 22H, the same effect can be obtained. Moreover, although the example which used 21 A of light emitting diodes as the light source 21 was demonstrated, not only this example but another light source may be used.

  DESCRIPTION OF SYMBOLS 2 ... Liquid crystal display panel 6 ... Display part Illumination unit 15 21 ... Light source 22C1 ... Incident surface 22 ... Light guide D1 ... Thickness direction D2 ... Direction substantially orthogonal to thickness direction 22H ... Recessed part

Claims (6)

A liquid crystal display panel having a display unit;
An illumination unit that illuminates the display unit,
The illumination unit includes a light source, a light incident surface on which light emitted from the light source is incident, and a light guide that is recessed from the light incident surface and extends in a direction substantially orthogonal to the thickness direction of the light guide on the light incident surface. A liquid crystal display device.   The liquid crystal display device according to claim 1, wherein the concave portion includes a plurality of side end surfaces having an angle formed with the incident surface larger than 90 degrees. The concave portion further includes a curved surface connected to the incident surface or the side end surface,
3. The liquid crystal display device according to claim 2, wherein the surface in contact with the curved surface has an angle formed with the incident surface of 90 degrees or more or parallel to the incident surface. The concave portion includes at least one curved side end surface connected to the incident surface,
2. The liquid crystal display device according to claim 1, wherein the surface in contact with the curved surface has an angle formed with the incident surface of 90 degrees or more or parallel to the incident surface. The recess has a first recess and a second recess arranged in the thickness direction of the light guide,
The liquid crystal display device according to claim 1, wherein a width of the first recess in the thickness direction of the light guide is different from a width of the second recess in the thickness direction of the light guide. The recess includes a first recess aligned in the thickness direction of the light guide, a second recess adjacent to the first recess, a third recess, and a fourth recess adjacent to the third recess. Have
The distance in the thickness direction of the light guide between the first recess and the second recess is different from the distance in the thickness direction of the light guide between the third recess and the fourth recess. The liquid crystal display device according to claim 1.

Images