JP2014191977A - Light source device and liquid crystal display device equipped with the light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device which can suppress the occurrence of brightness unevenness due to differences of light amount of emission light.SOLUTION: A light source device 1 comprises: light sources 11 which emits light; a light guide plate 13 having a first lateral surface 13c which is opposed to the light sources 11 and is extended along Y-direction, a second lateral surface 13d and a third lateral surface 13e which are opposed to each other and are extended along X-direction orthogonally crossing the Y-direction, a fourth lateral surface 13f located on the side opposite to the first lateral surface 13c and a principal plane 13a for emitting light from the light sources 11, made incident through the first lateral surface 13c; a first reflection member 14 arranged opposite to the second lateral surface 13d of the light guide plate 13; a first adhesion member B1 for adhering the first reflection member 14 and the second lateral surface 13d which are located on an edge part of the first lateral surface 13c side of the second lateral surface 13d; and a second adhesion member B2 for adhering the first reflection member 14 and the second lateral surface 13d which are located on the second lateral surface 13d at an interval from the first adhesion member B1 and is extended to the edge part of the fourth lateral surface 13f side.

Description

  The present invention relates to a light source device that emits light to a liquid crystal panel for displaying an image and a liquid crystal display device including the light source device.

  The light source device mounted on the liquid crystal display device includes a light source that emits light, a first side surface that faces the light source and extends along the first direction, and a second direction that faces each other and is orthogonal to the first direction. A second side surface and a third side surface extending along the first side surface, a fourth side surface located opposite to the first side surface, and a main surface for emitting light incident from the plurality of light sources through the first side surface to the liquid crystal panel. A light guide plate is provided (see, for example, Patent Document 1).

  Furthermore, in such a light source device, in order to return the light emitted from the second side surface of the light guide plate into the light guide plate, the first reflecting member is disposed facing the second side surface. Moreover, the 2nd side surface of the 1st reflection member and the light-guide plate is adhere | attached by the adhesive member extended from the edge part of the 1st side surface side to the edge part of the 4th main surface side.

JP 2005-38771 A

  However, in the light source device as described above, when the light in the light guide plate enters the adhesive member, the light may be irregularly reflected by the adhesive member. Therefore, when light is incident on the adhesive member located near the light source side end of the second side surface of the light guide plate, there is a possibility that the light is irregularly reflected near the first side surface of the main surface of the light guide plate. When light is diffusely reflected in the vicinity of the first side surface of the light guide plate, the amount of light emitted from the portion near the first side surface of the main surface of the light guide plate is increased, but the amount of light directed toward the fourth side surface of the light guide plate is increased. Therefore, the amount of light emitted from the portion near the fourth side surface of the main surface of the light guide plate may be reduced.

  That is, the amount of light emitted from the portion near the first side surface of the main surface of the light guide plate is larger than the amount of light emitted from the portion near the fourth side surface of the main surface of the light guide plate. There is a problem that a difference occurs in the amount of light emitted from the main surface of the optical plate, and uneven brightness may occur.

  The present invention has been conceived under such circumstances, and an object of the present invention is to provide a light source device capable of suppressing the occurrence of luminance unevenness due to a difference in the amount of emitted light.

  The light source device according to the present invention includes a light source that emits light, a first side surface facing the light source, extending along a first direction, and a second direction facing each other and perpendicular to the first direction. A light guide plate having a second side surface and a third side surface extending in a fourth direction, a fourth side surface opposite to the first side surface, and a main surface that emits light from a light source incident through the first side surface; Adhering the first reflecting member disposed opposite to the second side surface of the light guide plate and the first reflecting member and the second side surface located at the end of the second side surface on the first side surface side A first adhesive member to be bonded, and the first reflective member and the second side surface, which are located on the second side surface and spaced from the first adhesive member and extending to the end portion on the fourth side surface side And a second adhesive member.

  A liquid crystal display device according to the present invention includes the light source device and a liquid crystal panel disposed to face the main surface of the light guide plate.

  In the light source device according to the present invention, the first adhesive member located at the end portion of the second side surface of the light guide plate on the first side surface bonds the first reflecting member and the second side surface. A second adhesive member that extends from the adhesive member to an end portion on the fourth side surface that is located on the second side surface with a gap therebetween bonds the first reflective member and the second side surface. That is, there is no adhesive member in a portion between the first adhesive member and the second adhesive member. Accordingly, it is possible to reduce the occurrence of irregular reflection of light in the vicinity of the light source on the second side surface of the light guide plate, so that the light from the light source can easily reach the fourth side surface side of the light guide plate, and the first light guide plate side. The difference in the amount of light emitted from the main surface can be reduced, and the occurrence of uneven brightness can be suppressed.

  Since the liquid crystal display device according to the present invention includes the light source device described above, the display quality can be improved.

It is a top view showing the light source device which concerns on embodiment of this invention. It is sectional drawing along the II line of the light source device of FIG. It is sectional drawing along the II-II line of the light source device of FIG. It is a figure showing the light-guide plate and 1st reflection member seen from the 2nd side surface side. It is a top view showing a liquid crystal display device. It is a top view showing a liquid crystal panel. It is sectional drawing along the III-III line of the liquid crystal display device of FIG. It is a figure showing the light-guide plate and 1st reflection member seen from the 2nd side surface, Comprising: It is a figure showing a display area, a 1st adhesion member, and a 2nd adhesion member.

  First, a light source device 1 according to an embodiment of the present invention will be described with reference to FIGS.

  The light source device 1 includes a light source 11, a mounting substrate 12, a light guide plate 13, a first reflecting member 14, a second reflecting member 15, a third reflecting member 16, a diffusing member 17, and a prism plate 18. I have. The light source 11 has a function of emitting light. The plurality of light sources 11 are arranged to face the first side surface 13 c of the light guide plate 13. The plurality of light sources 11 are arranged along one side of the first main surface 13 a of the light guide plate 13. That is, as shown in FIG. 1, the plurality of light sources 11 are arranged along the Y direction.

  In the present embodiment, an LED (Light Emitting Diode) element is used as the light source 11, but the present invention is not limited to this. For example, an EL (Electro-Luminescence) element may be used.

  Further, although the point light source is employed as the light source 11 of the present embodiment, the present invention is not limited to this, and a line light source such as a cold cathode tube may be employed.

  The mounting substrate 12 is a substrate on which the light source 11 is mounted. A wiring pattern is formed on the mounting substrate 12, and the wiring pattern is connected to the light source 11. When a voltage is supplied from the power source to the light source 11 through this wiring pattern, light is emitted from the light source 11 toward the side surface 13 c of the light guide plate 13.

The light guide plate 13 has a function of emitting light incident from the first side surface 13c from the first main surface 13a. The light guide plate 13 is formed of a light-transmitting material, and is formed of a resin such as an acrylic resin or a polycarbonate resin. In addition, although the light guide plate 13 in the present embodiment has a rectangular parallelepiped shape, it is not limited to this.

  As shown in FIGS. 1 and 2, the light guide plate 13 has a first main surface 13a, a second main surface 13b, a first side surface 13c, a second side surface 13d, a third side surface 13e, and a fourth side surface 13f. .

  The first main surface 13 a is a surface that emits light from the light guide plate 13 toward the liquid crystal panel 2. The second main surface 13b is a surface located on the side opposite to the first main surface 13a. The first side surface 13c is a surface located between the first main surface 13a and the second main surface 13b, and is a surface on which the light source 11 is disposed facing. The second side surface 13d is a surface located between the first main surface 13a and the second main surface 13b and is a surface extending in the X direction. The third side surface 13e is a surface located between the first main surface 13a and the second main surface 13b and extending in the X direction. That is, the third side surface 13e is a surface located on the opposite side to the second side surface 13d. The fourth side surface 13f is a surface located between the first main surface 13a and the second main surface 13b, and is a surface located on the opposite side to the first side surface 13c.

  The second side surface 13d and the third side surface 13e in the present embodiment are adjacent to the first side surface 13c, but may not be adjacent to each other. Further, chamfering may be performed on corner portions located between the side surfaces of the light guide plate 13.

  The diffuser 13A has a function of diffusing light. The diffuser 13A is disposed on the second main surface 13b of the light guide plate 13. The diffuser 13A is made of resin or the like. Note that by forming irregularities on the second main surface 13b of the light guide plate 13, the irregularities may be used as the diffuser 13A. Further, the distance between the first main surface 13a and the second main surface 13b of the light guide plate 13 is decreased from the first side surface 13c side to the fourth side surface 13f, and the second main surface 13b is inclined to diffuse light. You may let them. The diffuser 13A in the present embodiment is circular in plan view, but is not limited to this.

  The first reflecting member 14 has a function of reflecting light toward the light guide plate 13. A part of the first reflecting member 14 faces the second side surface 13d of the light guide plate 13, and extends along the second side surface 13d. That is, a part of the first reflecting member 14 extends along one side of the first main surface 13 a of the light guide plate 13. The other part of the first reflecting member 14 faces the second main surface 13 b of the light guide plate 13. That is, the first reflecting member 14 has a portion facing the second side surface 13d of the light guide plate 13 and a portion facing the second main surface 13b. The first reflecting member 14 can be formed by forming a metal film on the surface of a substrate made of resin, for example. The first reflecting member 14 does not have to have a portion facing the second main surface 13b of the light guide plate 13.

  The first adhesive member B1 has a function of bonding the first reflecting member 14 to the second side surface 13d of the light guide plate 13. The first adhesive member B1 is disposed on the second side surface 13d of the light guide plate 13. As shown in FIGS. 1 and 4, the first adhesive member B <b> 1 is located at the end of the second side surface 13 d of the light guide plate 13 on the first side surface 13 c side. That is, the first adhesive member B1 bonds the end portion of the second side surface 13d of the light guide plate 13 and the end portion of the first reflecting member 14 on the first side surface 13c side of the second side surface 13d.

As shown in FIG. 4, the width W _B1 of the formation region of the first adhesive member B1 in this embodiment is set to 10 mm, for example.

  The second adhesive member B2 has a function of adhering the first reflecting member 14 to the second side surface 13d of the light guide plate 13. The second adhesive member B2 is disposed on the second side surface 13d of the light guide plate 13. As shown in FIGS. 2 and 4, the second adhesive member B2 extends from the first adhesive member B1 to the end portion on the fourth side surface 13f side with a space therebetween. That is, as shown in FIG. 4, the second adhesive member B2 is not in contact with the first adhesive member B1.

As shown in FIG. 4, the width W _B2 of the formation region of the second adhesive member B2 in this embodiment is set to 145 mm, for example.

  As shown in FIG. 4, the distance W between the first adhesive member B1 and the second adhesive member B2 in this embodiment is set to 25 mm, for example.

  The sixth adhesive member B6 has a function of adhering the first reflecting member 14 to the second main surface 13b of the light guide plate 13. The sixth adhesive member B6 is disposed on the second main surface 13b of the light guide plate 13. The sixth adhesive member B <b> 6 extends along one side of the second main surface 13 b of the light guide plate 13. As shown in FIG. 1, the sixth adhesive member B6 extends in the X direction. That is, the sixth adhesive member B6 fixes the end portion of the first reflecting member 14 in the Y direction to the second main surface 13b.

  The second reflecting member 15 has a function of reflecting light toward the light guide plate 13. It faces the third side surface 13e of the light guide plate 13, and extends along the third side surface 13e. That is, part of the second reflecting member 15 extends along one side of the first main surface 13 a of the light guide plate 13. The second reflecting member 15 is formed by forming a metal film on the surface of a substrate made of resin, for example.

  The third adhesive member B3 has a function of bonding the second reflecting member 15 to the third side surface 13e of the light guide plate 13. The third adhesive member B3 is disposed on the third side surface 13e of the light guide plate 13. Further, as shown in FIG. 1, the third adhesive member B <b> 3 is located at the end portion of the third side surface 13 e of the light guide plate 13 on the first side surface 13 c side. That is, the third adhesive member B3 bonds the end portion of the third side surface 13e of the light guide plate 13 and the end portion of the second reflecting member 15 on the first side surface 13c side of the third side surface 13e. Further, the third adhesive member B3 is disposed corresponding to the first adhesive member B1.

Note that the width of the formation region of the third adhesive member B3 in the present embodiment can be set similarly to the width W _B1 of the formation region of the first adhesive member B1.

  The fourth adhesive member B4 has a function of bonding the second reflecting member 15 to the third side surface 13e of the light guide plate 13. The fourth adhesive member B4 is disposed on the third side surface 13e of the light guide plate 13. The fourth adhesive member B4 extends toward the fourth side surface 13f of the third side surface 13e with a space from the third adhesive member B3. That is, as shown in FIG. 1, the fourth adhesive member B4 is not in contact with the third adhesive member B3. Further, the fourth adhesive member B4 is disposed corresponding to the second adhesive member B2.

The width of the formation region of the fourth adhesive member B4 in the present embodiment can set the same as the width W _B2 of the formation region of the second adhesive member B2.

  The third reflecting member 16 has a function of reflecting light toward the light guide plate 13. The third reflecting member 16 faces the fourth side surface 13f of the light guide plate 13 and extends along the fourth side surface 13f. The third reflecting member 16 is formed by forming a metal film on the surface of a substrate made of resin, for example.

  The fifth adhesive member B5 has a function of adhering the third reflecting member 16 to the fourth side surface 13f of the light guide plate 13. The fifth adhesive member B5 is disposed on the fourth side surface 13f of the light guide plate 13. Further, as shown in FIG. 1, the fifth adhesive member B5 extends along one side of the first main surface 13a. That is, the fifth adhesive member B5 extends in the Y direction. The fifth adhesive member B5 adheres the fourth side surface 13f of the light guide plate 13 and the third reflecting member 16, so that the light emitted from the light guide plate 13 can be favorably reflected to the light guide plate 13.

  Examples of the first adhesive member B1 to the sixth adhesive member B6 include resin adhesives such as silicone resin, epoxy resin, and acrylic resin.

The diffusion plate 17 is disposed to face the first main surface 13a of the light guide plate 13. The diffusion plate 17 has a role of improving the uniformity of the luminance of light emitted from the first main surface 13 a of the light guide plate 13 toward the liquid crystal panel 2. The diffusion plate 17 is formed by applying a resin containing silica beads or the like onto a substrate made of a resin material such as PET, and then curing the resin.

  The prism plate 18 is disposed to face the first main surface 13a of the light guide plate 13 with the diffusion plate 17 in between. The prism plate 18 has a function of refracting light incident on the prism plate 18 in the Z direction.

  In the light source device 1, in addition to the first adhesive member B1 positioned at the end of the second side surface 13d of the light guide plate 13 on the first side surface 13c side bonding the first reflecting member 14 and the second side surface 13d, A second adhesive member B2 extending from the first adhesive member B1 to the end portion on the fourth side face 13f located on the second side face 13d at a distance from the first adhesive member B1 adheres the first reflecting member 14 and the second side face 13d. . There is no adhesive member in the vicinity of the light source 11 on the second side surface 13d of the light guide plate 13, that is, the portion between the first adhesive member B1 and the second adhesive member B2. This can reduce the occurrence of irregular reflection of light in the vicinity of the light source 11 on the second side surface 13d of the light guide plate 13, so that the light from the light source 11 can easily reach the side of the fourth side surface 13f of the light guide plate 13. Therefore, it is possible to reduce an increase in the amount of light emitted from the portion near the first side surface 13c of the first main surface 13a of the light guide plate 13, and a small amount of light emitted from the portion near the fourth side surface 13f. Can be reduced. As described above, in the light source device 1, the difference in the amount of light emitted from the first main surface 13a of the light guide plate 13 can be reduced, and the occurrence of uneven brightness can be suppressed.

  Further, in the light source device 1, the first adhesive member B1 located at the end of the second side surface 13d of the light guide plate 13 on the first side surface 13c side bonds the first reflecting member 14 and the second side surface 13d. For example, when the first adhesive member B1 is not disposed, the first reflecting member 14 and the second side surface 13d are not bonded, and therefore the second side surface of the light guide plate 13 on the first side surface 13c side of the second side surface 13d. There is a possibility that the positional relationship between the end of 13d and the end of the first reflecting member 14 is not fixed, and the light emitted from the second side surface 13d of the light guide plate 13 cannot be sufficiently reflected to the light guide plate 13 by the first reflecting member 14. There is. On the other hand, since the first adhesive member B1 adheres the end of the second side surface 13d of the light guide plate 13 and the end of the first reflection member 14, the positions of the first reflection member 14 and the second side surface 13d. The relationship can be fixed satisfactorily, and the light emitted from the second side surface 13d of the light guide plate 13 is easily reflected on the first reflecting member 14.

  In the light source device 1, the second adhesive member B <b> 2 located at the end of the third side surface 13 e of the light guide plate 13 on the first side surface 13 c side bonds the second reflecting member 15 and the third side surface 13 e. In addition, the fourth adhesive member B4, which is located on the third side surface 13e with a space from the second adhesive member B2 and extends to the end portion on the fourth side surface 13f side, bonds the second reflective member 15 and the third side surface 13e. doing. There is no adhesive member in the portion near the light source 11 on the third side surface 13e of the light guide plate 13, that is, the portion between the third adhesive member B3 and the fourth adhesive member B4. As a result, it is possible to reduce the occurrence of irregular reflection of light in the vicinity of the light source 11 on the third side surface 13e of the light guide plate 13, so that the light can easily reach the fourth side surface 13f side of the light guide plate 13. Therefore, it is possible to reduce an increase in the amount of light emitted from the portion near the first side surface 13c of the first main surface 13a of the light guide plate 13, and a small amount of light emitted from the portion near the fourth side surface 13f. Can be reduced. As described above, the difference in the amount of light emitted from the first main surface 13a of the light guide plate 13 can be reduced, and the occurrence of uneven brightness can be suppressed.

  Further, in the light source device 1, the third adhesive member B3 located at the end of the third side surface 13e of the light guide plate 13 on the first side surface 13c side bonds the second reflecting member 15 and the third side surface 13e. For example, when the third adhesive member B3 is not disposed, the positional relationship between the end portion of the third side surface 13e of the light guide plate 13 and the end portion of the second reflecting member 15 on the first side surface 13c side of the third side surface 13e. There is a possibility that the light emitted from the third side surface 13e of the light guide plate 13 cannot be sufficiently reflected to the light guide plate 13 without being fixed. On the other hand, since the third adhesive member B3 bonds the end of the second side surface 13d of the light guide plate 13 and the end of the second reflective member 15, the positions of the second reflective member 15 and the third side surface 13e. The relationship can be fixed well, and the light emitted from the third side surface 13e of the light guide plate 13 is easily reflected by the second reflecting member 15.

  Next, the liquid crystal display device 3 including the light source device 1 and the liquid crystal panel 2 will be described with reference to FIGS.

  As shown in FIGS. 5 to 7, the liquid crystal display device 3 includes a light source device 1 and a liquid crystal panel 2.

The liquid crystal panel 2 includes a first substrate 21, a second substrate 22, a liquid crystal layer 23, and a sealing material 24. The liquid crystal panel 2 adjusts the transmittance of light from the light source device 3 for each pixel by generating an electric field between the signal electrode and the common electrode to control the direction of the liquid crystal molecules in the liquid crystal layer 23, and displays displaying an image in the region _{E D.}

The first substrate 21, on the side opposite to the outer main surface 21a and the outer main surface 21a having a non-display area E _ND positioned outside the display region E _D and the display area E _D for displaying an image on the central portion The inner main surface 21b is located. The first substrate 21 is formed of a light-transmitting material such as glass or plastic.

  On the inner main surface 21b of the first substrate 21, a color filter, a light shielding film, a planarizing film, an alignment film (not shown), and the like are arranged.

  The second substrate 22 has an inner main surface 22a facing the inner main surface 21b of the first substrate 21, and an outer main surface 22b located on the opposite side of the inner main surface 22a. The second substrate 22 can be formed of the same material as the first substrate 21.

On the inner main surface 22a of the second substrate 22 in the display area E _D, a gate wiring, a gate insulating film, a source wiring, a thin film transistor, such as a signal electrode and the common electrode (not shown) is disposed.

  Note that the liquid crystal panel 2 of the present embodiment is a so-called lateral electric field that controls the direction of liquid crystal molecules in a liquid crystal layer by generating an electric field between a signal electrode and a common electrode disposed on one of the pair of substrates. The method is adopted. In this embodiment, the horizontal electric field method is adopted, but the present invention is not limited to this, and any method may be used. For example, a vertical electric field method may be adopted.

The liquid crystal layer 23 is disposed in a portion that overlaps the display region E _D of between the first substrate 21 and the second substrate 22. The liquid crystal layer 23 includes nematic liquid crystal or the like.

Figure 8 shows the positional relationship of the portion between the display region E _D and the first adhesive member B1 and the second adhesive member B2 of the liquid crystal panel 2. As shown in FIGS. 5 and 8, the portion between the first bonding member B1 and the second adhesive member B2, i.e., the portion where the adhesive member does not exist as across the boundary of the display area E _D and the non-display area E _ND Is arranged. Thus, it is possible to reduce that the irregular reflection of light inside and a portion located outside of the display region E _D occurs, the amount of light emitted from the first main surface 13a of the light guide plate 13 overlapping the display area E _D The difference can be reduced, the occurrence of uneven brightness is suppressed, and the display quality is improved.

As shown in FIG. 5, the positional relationship of the portion between the display region E _D and the third adhesive member B3 and the fourth adhesive member B4 of the liquid crystal panel 2 is also the same as described above.

The sealing material 24 has a function of bonding the first substrate 21 and the second substrate 22 together. Further, the sealing material 24 is disposed between the first substrate 21 and the second substrate 22. Sealing material 24 is disposed so as to surround the display region E _D in plan view. This sealing material 24 is formed of an epoxy resin or the like.

The first polarizing plate 25 has a function of selectively transmitting light in a predetermined vibration direction. As shown in FIG. 7, the first polarizing plate 25 is disposed on the outer principal surface 21 a of the first substrate 21 of the liquid crystal panel 2. The first polarizer 25 is positioned in the display area E _D.

  The second polarizing plate 26 has a function of selectively transmitting light in a predetermined vibration direction. As shown in FIG. 7, the second polarizing plate 26 is disposed on the outer principal surface 22 b of the second substrate 22. The second polarizing plate 26 is disposed so as to overlap the first polarizing plate 25.

  The liquid crystal display device 3 includes a light source device 1. Thereby, the luminance in the light emitted from the light source device 1 is made more uniform, the occurrence of display unevenness is reduced, and the display quality is improved.

  The present invention is not particularly limited to the above embodiment, and various changes and improvements can be made within the scope of the gist of the present invention. For example, in the above embodiment, the active matrix method using thin film transistors is adopted for the liquid crystal panel 2, but a passive matrix method may be adopted.

1 Light source device
11 Light source
12 Mounting board
13 Light guide plate
13a 1st main surface
13b Second main surface
13c 1st side
13d Second side
13e 3rd side
13f 4th side
13A diffuser
14 First reflector
15 Second reflector
16 3rd reflector B1 1st adhesive member B2 2nd adhesive member B3 3rd adhesive member B4 4th adhesive member B5 5th adhesive member B6 6th adhesive member
17 Diffuser
18 Prism plate 2 LCD panel
21 First board
21a 1st main surface
21b 2nd main surface
22 Second board
22a 1st main surface
22b 2nd main surface
23 Liquid crystal layer
24 Sealing material
25 First Polarizer
26 Second Polarizer 3 Liquid Crystal Display

Claims (4)

A light source that emits light;
A first side surface facing the light source and extending along a first direction, a second side surface and a third side surface facing each other and extending along a second direction perpendicular to the first direction, the first A light guide plate having a fourth side surface opposite to the side surface, and a main surface that emits light from the light source incident through the first side surface;
A first reflecting member disposed to face the second side surface of the light guide plate;
A first adhesive member for bonding the first reflective member and the second side surface, located at an end of the second side surface on the first side surface side;
A second adhesive member for adhering the first reflective member and the second side surface, which is located on the second side surface and spaced from the first adhesive member and extends to an end on the fourth side surface side; A light source device comprising: A second reflecting member disposed to face the third side surface of the light guide plate;
A third adhesive member for adhering the second reflective member and the third side surface, located at an end of the third side surface on the first side surface side;
A fourth adhesive member for adhering the second reflective member and the third side surface, which is located on the third side surface at a distance from the third adhesive member and extends to an end on the fourth side surface side; The light source device according to claim 1, further comprising: A third reflecting member disposed to face the fourth side surface of the light guide plate;
The light source device according to claim 2, further comprising a fifth adhesive member that adheres the third reflecting member and the fourth side surface. The light source device according to any one of claims 1 to 3,
A liquid crystal display device comprising: a liquid crystal panel disposed to face the main surface of the light guide plate.

Images