CN102901004B - Illuminator, liquid crystal indicator and electronic equipment - Google Patents

Abstract

The present invention provides an illuminating device capable of improving the uniformity of emission intensity of illuminating light from a light guide plate, a liquid crystal display device provided with the illuminating device, and an electronic device provided with the liquid crystal display device even if there are portions with wide intervals between light emitting elements. equipment. In the light guide plate (80) used for the lighting device (8), although the light-emitting elements 89 are arranged at the first interval (S 1 ) along the light incident portion (80a), in a part, the light-emitting elements 89 are arranged at the first interval (S ₁ ). S ₁ ) wide second interval (S ₂ ). Therefore, in the light guide plate (80), the outer edge area ( 80t), opposite to the position where the interval between the light emitting elements (89) becomes the second interval (S ₂ ), a rectangular groove (86) is formed with a width dimension (W) smaller than the second interval (S ₂ ). The second diffuse area (80u).

Description

Lighting device, liquid crystal display device and electronic equipment

technical field

The present invention relates to a lighting device including a light guide plate and a light emitting element, a liquid crystal display device including the lighting device, and electronic equipment including the liquid crystal display device.

Background technique

A liquid crystal display device equipped with a transmissive liquid crystal panel has an illumination device in which a plurality of light-emitting elements are arranged along the side end surface of the light guide plate that becomes the light incident portion, and the liquid crystal panels are stacked on the light exit surface side of the light guide plate (Patent Documents 1 to 4 ).

Among such patent documents 1 to 4, in the lighting device described in patent document 4, a light emitting element is mounted on one surface side of a substrate for a light source, and such a substrate for a light source is fixed to a frame with screws or the like.

Patent Document 1 Japanese Unexamined Publication No. 2010-118348

Patent Document 2 JP-A-2004-165124 Gazette

Patent Document 3 JP-A-2009-3081 Gazette

Patent Document 4 JP-A-2011-40388 Gazette

In such a lighting device, in order to improve the emission efficiency of the illumination light from the light guide plate and to make the intensity distribution of the illumination light uniform, the surface of the light guide plate on the light emission side or the surface opposite to the light emission side In the area where the image display areas of the liquid crystal panel overlap, a plurality of diffuse patterns including white dots and/or grooves are formed. Therefore, the light guide plate is provided with a diffusion area formed with a diffusion pattern and an outer edge area sandwiched between the diffusion area and the end of the light guide plate, and no diffusion pattern is formed in the outer edge area.

On the other hand, although most of the light emitting elements are mounted on the light source substrate at predetermined intervals, there may be portions where the intervals between the light emitting elements are wide. For example, when the light source substrate is fixed to the frame by screws that are locked between the light emitting elements, the intervals between the light emitting elements are wider at locations where the screws are arranged than at other locations. Furthermore, when a plurality of substrates for light sources are arranged, the intervals between the light emitting elements become wider between adjacent substrates for light sources than at other locations. As a result, there is a problem that when the light emitted from the light-emitting elements enters the diffused area of the light guide plate, the portion where the interval between the light-emitting elements becomes wider becomes a discontinuous portion where the light intensity is lower than the surrounding area, and the intensity distribution of the illumination light worse. Such a problem cannot be eliminated even if the density of the diffusion pattern in the diffusion area is optimized.

Contents of the invention

In view of the above problems, an object of the present invention is to provide an illuminating device capable of improving the uniformity of emission intensity of illuminating light from a light guide plate and a liquid crystal display device provided with the illuminating device even when there are portions with wide intervals between light emitting elements. device and electronic equipment including the liquid crystal display device.

In order to solve the above problems, the lighting device according to the present invention is characterized in that it has a light guide plate and a plurality of light emitting elements, and the light guide plate has a first main surface, a second main surface facing the first main surface, and a plurality of light emitting elements. A plurality of sides, the plurality of light-emitting elements are arranged along the first side of the plurality of sides; on the first main surface of the light guide plate, a first diffusion area formed with a first diffusion pattern is provided and an outer edge region arranged between the first diffusion region and the first side; a plurality of light emitting elements including a first light emitting element, a second light emitting element and a third light emitting element, between the first light emitting element and the first light emitting element A first interval is set between the second light-emitting elements, and a second interval wider than the first interval is set between the second light-emitting element and the third light-emitting element; The outer edge area at the position of the second interval is provided with a second diffusion area formed with a second diffusion pattern; the length of the second diffusion area in the direction in which the plurality of light emitting elements are arranged is set is narrower than the second interval.

In the lighting device according to the present invention, although there are portions where the interval between adjacent light emitting elements is the first interval and the second interval where the interval between adjacent light emitting elements is wider than the first interval exists among the plurality of light emitting elements. However, in the outer edge region of the light guide plate, between the first diffusion region and the second interval, a second diffusion region in which a second diffusion pattern is formed is provided. Therefore, when the light emitted from the light-emitting elements enters the light guide plate, the portion where the distance between the light-emitting elements becomes wider than other portions becomes a discontinuous portion with lower light intensity than the surrounding area, but when the light enters the first diffusion region Even if the distance between the light emitting elements becomes wider than other parts, the difference in light intensity with the surroundings is alleviated by the diffusion pattern formed in the second diffusion region. Therefore, even in the case where there are portions where the intervals between the light emitting elements are wide, the uniformity of the emission intensity of the illumination light from the light guide plate can be improved.

In the present invention, the second main surface of the light guide plate serves as a light exit surface.

In the present invention, preferably: the first diffusion pattern and the second diffusion pattern are grooves; Among the first direction and the second direction, in the first direction, a plurality of the grooves are arranged in a straight line, and a plurality of rows of grooves are parallel in the second direction; in the second diffusion area The groove is formed such that the longitudinal direction faces the first direction. According to such a configuration, the grooves can be provided in the second diffusion region by the same method as the method of forming the grooves in the first diffusion region.

In the present invention, preferably: the light guide plate is formed by irradiating a laser beam on a resin plate to form the groove. According to such a configuration, grooves can be efficiently formed in arbitrary positions of the light guide plate.

In the present invention, it is preferable that the plurality of light emitting elements are provided on one surface side of the light source substrate; and that there is a structure protruding from the light source substrate on the one surface side at the portion of the second space. a body; a portion of an end portion of the second diffusion region on the side of the structure body facing the structure body is located on the side of the first diffusion region relative to other portions of the end portion. According to such a configuration, although the light intensity becomes higher at the portion where the structure exists due to the reflection of the structure, but at the portion facing the structure, the end of the second diffusion region retreats behind the second diffusion region. 1 Diffuse area side, so it can effectively alleviate the difference in light intensity with the surrounding.

In the present invention, the second diffusion region may have a rectangular configuration.

In the present invention, it is possible to employ a configuration in which the second diffusion region has a semicircular shape with a chord directed toward the first diffusion region. Furthermore, in the present invention, the second diffusion region may be configured in a trapezoidal or triangular shape with the bottom facing the first diffusion region. According to such a configuration, in the second diffusion region, the diffusion of light on the side of the light incident portion is suppressed to be low, and on the other hand, sufficient diffusion of light can be performed at a position close to the first diffusion region. Therefore, when light enters the diffusion region, the difference in light intensity from the surroundings can be effectively alleviated even at a portion where the interval between the light emitting elements is wider than other portions.

The illuminating device to which the present invention is applied can be used in a liquid crystal display device including a liquid crystal panel arranged to be superimposed on the light emitting surface side of the light guide plate.

The liquid crystal display device according to the present invention can be used in electronic equipment such as liquid crystal televisions.

Description of drawings

1 is an explanatory diagram of a liquid crystal television (electronic device) including a liquid crystal display device according to Embodiment 1 of the present invention.

2 is an explanatory diagram showing the overall configuration of the liquid crystal display device according to Embodiment 1 of the present invention.

3 is an exploded perspective view of the liquid crystal display device according to Embodiment 1 of the present invention when it is disassembled in more detail.

4 is a cross-sectional view of a liquid crystal display device according to Embodiment 1 of the present invention.

5 is an explanatory view showing the configuration around a light source substrate used in the lighting device of the liquid crystal display device according to Embodiment 1 of the present invention.

6 is an explanatory diagram of a light guide plate used in the lighting device of the liquid crystal display device according to Embodiment 1 of the present invention.

Fig. 7 is an explanatory diagram of the first groove shown in Fig. 6 .

FIG. 8 is an explanatory view showing a method of manufacturing the light guide plate shown in FIG. 6 .

9 is an explanatory diagram of a light guide plate used in the lighting device of the liquid crystal display device according to Embodiment 2 of the present invention.

10 is an explanatory diagram of a light guide plate used in the lighting device of the liquid crystal display device according to Embodiment 3 of the present invention.

Explanation of symbols

8··lighting device, 10··LCD panel, 80··light guide plate, 80a··light incident part, 80b··light exit surface (second main surface), 80c··bottom surface (first main surface), 80s・・1st diffusion area, 80t・・outer edge area, 80u・・2nd diffusion area, 86・・groove (diffuse pattern), 89・・light emitting element (light source), 100・・LCD , 100a · · image display area, 690 · · screw head (structure), 860 · · groove column

detailed description

A mode in which the present invention is applied to a liquid crystal display device for a liquid crystal television will be described with reference to the drawings. In addition, in the drawings referred to in the following description, the scale is changed for each layer and/or each member so that each layer and/or each member has a size recognizable on the drawing. In addition, in the following description, one of the directions intersecting each other in the in-plane direction of the light guide plate and/or liquid crystal panel (the direction in which the long side of the light guide plate and/or liquid crystal panel (display panel) ) is the X-axis direction, and the other side (the direction in which the short sides of the light guide plate and/or liquid crystal panel (display panel) shown in the drawings extend) is the Y-axis direction, so as to cross the X-axis direction and the Y-axis direction (The direction in which the light guide plate and the liquid crystal panel are laminated as shown in the drawings) is the Z-axis direction. In addition, in the drawings referred to below, one side in the X-axis direction is referred to as the X1 side, the other side is referred to as the X2 side, and one side in the Y-axis direction (the direction in which the protruding portion of the liquid crystal panel is arranged) is referred to as Y1. side, the other side opposite to this is the Y2 side, one side in the Z-axis direction (direction toward the back of the light guide plate) is the Z1 side (lower side), and the other side opposite to this (outgoing illumination light and/or the side where the light is displayed) is shown as the Z2 side (upper side).

Embodiment 1

(overall composition)

1 is an explanatory diagram of a liquid crystal television (electronic device) including a liquid crystal display device according to Embodiment 1 of the present invention. FIGS. and a block diagram showing the electrical configuration of the liquid crystal display device.

An electronic device 2000 shown in FIG. 1( a ) is a liquid crystal television, and includes a liquid crystal display device 100 and/or a frame 2010 for the television, and the like. The liquid crystal display device 100 includes a liquid crystal panel 10 (display panel) described later, an image signal supply unit 270 that supplies image signals to the liquid crystal panel 10 , and an illumination device 8 that supplies illumination light to the liquid crystal panel 10 . Furthermore, the liquid crystal display device 100 includes a scanning line driving circuit 104 for driving scanning lines extending in the X-axis direction in the liquid crystal panel 10 and a data line driving circuit 104 for driving data lines extending in the Y-axis direction in the liquid crystal panel 10. circuit 101. As for the scanning line driving circuit 104 and the data line driving circuit 101 , a configuration in which both are built in the liquid crystal panel 10 can be employed. In addition, one of the scanning line driving circuit 104 and the data line driving circuit 101 may be incorporated in the liquid crystal panel 10 , and the other may be incorporated in a driving IC that is COG-mounted on the liquid crystal panel 10 . In addition, one of the scanning line driving circuit 104 and the data line driving circuit 101 can be built in the liquid crystal panel 10, and the other can be built in a driving IC, and the driving IC is mounted on a circuit board electrically connected to the liquid crystal panel 10. . Furthermore, a configuration in which both the scanning line driving circuit 104 and the data line driving circuit 101 are incorporated in a driving IC separate from the liquid crystal panel 10 may be adopted.

In this form, the illuminating device 8 has a light guide plate 80 arranged to be stacked on the liquid crystal panel 10 , and a plurality of light emitting devices arranged along the side end surface (side surface) of the light incident portion 80 a among the side end surfaces (side surfaces) of the light guide plate 80 . An element 89 , a light source substrate 88 on which a plurality of light emitting elements 89 are mounted, and a light source driving unit 280 that drives the light emitting elements 89 . In this embodiment, the liquid crystal panel 10 is a quadrangle and has four sides 10a, 10b, 10c, and 10d. Among these sides 10a, 10b, 10c, and 10d, side 10a is a long side located on one side Y1 in the Y-axis direction, side 10b is a long side located on the other side Y2 in the Y-axis direction, and side 10c is a long side located in the X-axis direction. The short side of one side X1, and the side 10d is the short side of the other side X2 in the X-axis direction. Corresponding to such a shape, the light guide plate 80 has four side end surfaces (side surfaces) 801 , 802 , 803 , and 804 . Among these side end surfaces (side surfaces) 801 to 804, the side end surface (side surface) 801 is located on the long side of one side Y1 in the Y-axis direction, and the side end surface (side surface) 802 is located on the long side of the other side Y2 in the Y-axis direction. The end surface (side surface) 803 is located on the short side of one side X1 in the X-axis direction, and the side end surface (side surface) 804 is located on the short side of the other side X2 in the X-axis direction. In this embodiment, among the four side end surfaces 801, 802, 803, and 804 of the light guide plate 80, the two side end surfaces (side surfaces) 801, 802 that face each other in the short direction (Y-axis direction) serve as the light incident portion 80a. . Therefore, the light emitting element 89 is arranged along the two side end surfaces (side surfaces) 801 , 802 (light incident portion 80 a ) of the light guide plate 80 , and the light source substrate 88 is arranged along the two side end surfaces (side surfaces) 801 , 802 of the light guide plate 80 . 802 (light incident portion 80a ) are each extended.

(Concrete Configuration of Liquid Crystal Display Device 100 )

2 is an explanatory view showing the overall configuration of the liquid crystal display device 100 according to Embodiment 1 of the present invention, and FIGS. 2( a ) and ( b ) are a perspective view and an exploded perspective view of the liquid crystal display device 100 . FIG. 3 is an exploded perspective view of the liquid crystal display device 100 according to Embodiment 1 of the present invention when it is disassembled in more detail. 4 is a cross-sectional view of the liquid crystal display device 100 according to Embodiment 1 of the present invention. FIGS. A cross-sectional view when cut, and a cross-sectional view when the liquid crystal display device 100 is cut along line BB′ in FIG. 1( a ).

In FIGS. 2 , 3 and 4 , the liquid crystal display device 100 of this embodiment basically includes an illumination device 8 called a so-called backlight device, and a transmissive liquid crystal panel 10 stacked on the top surface of the illumination device 8 . In the liquid crystal display device 100 , the illuminating device 8 includes a metal first frame 40 (lower metal frame) arranged to cover the back surface of the light guide plate 80 on the lower side (one side Z1 in the Z-axis direction). The second frame 30 (resin frame) made of resin that holds the end of the liquid crystal panel 10 and surrounds the lighting device 8 and is disposed on the upper side of the second frame 30 (the other side Z2 in the Z-axis direction) The third frame 50 (upper metal frame) made of metal.

The second frame 30 has a rectangular frame shape that holds the end of the liquid crystal panel 10 and surrounds the periphery of the liquid crystal panel 10. In this embodiment, the second frame 30 includes four sides corresponding to the liquid crystal panel 10 and is divided for each side. 4 frame plates 31, 32, 33, 34. In this embodiment, the second frame 30 is black and functions as a light absorbing member to prevent generation of stray light in the lighting device 8 . The frame plates 31, 32, 33, 34 respectively have side plate portions 311, 321, 331, 341 extending downward on the outer surfaces of the frame plates 31, 32, 33, 34, and the side plate portions 311, 321, 331, 341, the upper plate portions 315, 325, 335, 345 (end plate portions) whose upper edge is bent inward, and the protruding plate portion 312 protruding inward from the halfway position in the height direction of the upper plate portions 315, 325, 335, 345, 322, 332, 342. Therefore, inside the frame plates 31, 32, 33, 34, step portions 313, 323, 333, 343 are formed by the protruding plate portions 312, 322, 332, 342. The sections 312 , 322 , 332 , and 342 hold the liquid crystal panel 10 . In addition, the light guide plate 80 and/or the light emitting element 89 of the lighting device 8 are disposed on the lower side of the protruding plate portions 312 , 322 , 332 , and 342 .

The first frame 40 is formed by press working or the like on a thin metal plate such as a SUS plate. The first frame 40 includes a bottom plate portion 45 and three side plate portions 42 , 43 , 44 erected from three sides except for one side Y1 in the Y-axis direction among the outer peripheral edges of the bottom plate portion 45 , and opens as a top surface. rectangular box shape. The side plate portions 321 , 331 , and 341 of the second frame 30 overlap the outer sides of the side plate portions 42 , 43 , and 44 of the first frame 40 as described above. Furthermore, the side plate portion 311 of the second frame 30 covers one side Y1 of the first frame 40 in the Y-axis direction.

Like the first frame 40, the third frame 50 is also formed by press working or the like on a thin metal plate such as a SUS plate. The third frame 50 has a rectangular upper plate portion 55 (end plate portion) and four side plate portions 51 , 52 , 53 , 54 bent downward from the outer peripheral edge of the upper plate portion 55 , and forms a rectangular box with an open bottom. shape. The side plate portions 51 , 52 , 53 , and 54 overlap the outer sides of the side plate portions 311 , 321 , 331 , and 341 of the second frame 30 . A rectangular window 550 for emitting light emitted from the liquid crystal panel 10 is formed on the upper plate portion 55 , and the upper plate portion 55 covers the entire circumference of the outer peripheral end portion on the display light emitting side of the liquid crystal panel 10 .

The third frame 50 , the second frame 30 , and the first frame 40 configured in this way are connected by screws (not shown) or the like, and hold the liquid crystal panel 10 and/or the lighting device 8 inside. Here, as shown in FIG. 4 , flexible sheets 91 and 92 are attached to the bottom surface and the top surface of the protruding plate portions 312 , 322 , 332 , and 342 of the second frame 30 . Therefore, when assembling the liquid crystal display device 100 , the liquid crystal panel 10 is supported by the projecting plate portions 312 to 342 via the flexible sheet 92 . Furthermore, when assembling the liquid crystal display device 100 , the lighting device 8 is supported via the flexible sheet 91 . Furthermore, when assembling the liquid crystal display device 100 , the optical sheets (diffusing sheet 182 , prism sheets 183 , 184 , etc.) of the lighting device 8 are suppressed by the flexible sheet 91 so that floating and/or misalignment do not occur.

(Configuration of Liquid Crystal Panel 10 )

As shown in FIG. 2 , FIG. 3 and FIG. 4 , the liquid crystal panel 10 has a quadrangular planar shape, includes an element substrate 11 on which pixel electrodes (not shown) etc. are formed, and is opposed to the element substrate 11 with a predetermined gap. The opposite substrate 12 arranged to face each other, and the rectangular frame-shaped sealing material 14 for bonding the opposite substrate 12 and the element substrate 11 together. In such a liquid crystal panel 10 , the liquid crystal layer 13 is held in a region surrounded by the sealing material 14 . The element substrate 11 and the counter substrate 12 include a light-transmitting substrate such as a glass substrate. In the element substrate 11, a plurality of scanning lines (not shown) extend in the X-axis direction, and on the other hand, a plurality of data lines extend in the Y-axis direction, corresponding to intersections of the scanning lines and data lines (not shown), A switch element (not shown) and a pixel electrode are provided.

In this embodiment, the counter substrate 12 is arranged on the output side of the display light, and the element substrate 11 is arranged on the illuminating device 8 side. In addition, on the surface of the opposing substrate 12 that faces the element substrate 11, a frame layer 120 including a rectangular frame-shaped light-shielding layer is formed along the inner edges of the four sides of the sealing material 14. The area defined by the inner edge of 120 is the image display area 100a. In addition, the inner edge of the upper plate portion 55 of the third frame 50 is located halfway in the width direction of the frame layer 120 , and the window 550 of the third frame 50 overlaps the image display area 100 a and the inner peripheral portion of the frame layer 120 .

The liquid crystal panel 10 is configured as a TN (Twisted Nematic, twisted nematic) method, an ECB (Electrically Controlled Birefringence, electrically controlled birefringence) method or a VAN (Vertical Aligned Nematic, vertical alignment nematic) method liquid crystal panel, and is formed on the element substrate 11 For the pixel electrodes, a common electrode (not shown) is formed on the counter substrate 12 . Also, when the liquid crystal panel 10 is an IPS (In Plane Switching) type liquid crystal panel and/or an FFS (Fringe Field Switching, fringe field switching) type liquid crystal panel, the common electrode is provided on the element substrate 11 side. In addition, the element substrate 11 may also be disposed on the emission side of the display light with respect to the counter substrate 12 . An upper polarizing plate 18 is stacked on the top surface of the liquid crystal panel 10 , and a lower polarizing plate 17 is arranged between the bottom surface of the liquid crystal panel 10 and the illuminating device 8 .

In this form, the element substrate 11 is larger than the counter substrate 12 . Therefore, the element substrate 11 has a protruding portion 110 protruding from the end of the counter substrate 12 on one side Y1 in the Y-axis direction, and a plurality of flexible wiring boards 200 are connected to the top surface of the protruding portion 110 . The flexible wiring board 200 is connected to a circuit board 250 including a rigid board. On such a circuit board 250, a control IC (not shown) constituting the image signal supply unit 270 described with reference to FIG. An IC (not shown) for driving a light source of the part 280 .

(Configuration of lighting device 8)

5 is an explanatory diagram showing the configuration around a light source substrate 88 used in the lighting device 8 of the liquid crystal display device 100 according to Embodiment 1 of the present invention, and FIGS. 5( a ) and ( b ) schematically show the light source substrate. An explanatory diagram of the situation on the side of one surface 881 of 88 and an explanatory diagram schematically showing the situation of the other side of the light source substrate 88 on the side of surface 882 . The configurations of the light emitting elements 89 and/or the light source substrate 88 arranged on the two side end surfaces 801 and 802 (light incident portions 80 a ) facing each other in the Y-axis direction of the light guide plate 80 are the same. Therefore, in FIG. 5( a ), the light emitting element 89 and/or the light source substrate 88 arranged on the side end surface 802 of the light guide plate 80 are shown, and in FIG. (Side surface) 801 is a light source substrate 88 and the like.

As shown in FIGS. 3 and 4 , the illuminating device 8 includes a light guide plate 80 stacked on the bottom surface side of the liquid crystal panel 10 , and a light-emitting surface 89 a facing the light-incident portion 80 a of the light-guide plate 80 . A plurality of light emitting elements 89 are arranged on one side (one side X1 in the X-axis direction) toward the other end side (the other side X2 in the X-axis direction). In this embodiment, a plurality of light emitting elements 89 are mounted on one surface 881 of the light source substrate 88 extending in the X-axis direction along the light incident portion 80a. The light emitting element 89 is an LED (Light Emitting Diode) that emits white light, and emits the light source light as divergent light.

In the lighting device 8 of this embodiment, among the side end surfaces (side surfaces) 801 , 802 , 803 , and 804 of the light guide plate 80 , the two side end surfaces (side surfaces) 801 , 802 facing each other in the Y-axis direction are used as light incident portions. 80a. Therefore, the plurality of light-emitting elements 89 direct the light-emitting surface 89 a toward the two light-incident portions 80 a (side end surfaces/side surfaces 801 and 802 ) of the light guide plate 80 , and from each of the two light-incident portions 80 a (side end surfaces/side surfaces 801 and 802 ) One end side is arranged toward the other end side. The two light source substrates 88 extend along the two light incident portions 80 a (side end surfaces 801 , 802 ), and a plurality of light emitting elements 89 are mounted on one surface 881 of each of the two light source substrates 88 .

In this embodiment, the light guide plate 80 is a translucent resin plate including acrylic resin, polymethylstyrene resin, polycarbonate resin, etc., and the bottom surface 80c of the light guide plate 80 (and the light exit surface/second main surface The reflective sheet 187 is arranged to overlap between the surface on the opposite side of 80b/opposite surface...the first main surface) and the bottom plate portion 45 of the first frame 40 . The resin plate used for the light guide plate 80 is formed by extrusion molding and/or injection molding or the like.

Further, optical sheets such as a diffusion sheet 182 and prism sheets 183 and 184 are stacked between the top surface (light exit surface 80 b /second main surface) of the light guide plate 80 and the liquid crystal panel 10 . The diffusion sheet 182 includes a sheet provided with a coating layer of a translucent resin such as acrylic resin and/or polycarbonate resin dispersed in silica particles or the like. In this embodiment, the two prism sheets 183 and 184 are arranged such that their ridgelines are perpendicular to each other. Therefore, the illuminating light emitted from the light emitting surface 80b of the light guide plate 80 is diffused in all directions by the diffusion sheet 182, and then passes through the two prism sheets 183, 184 to generate directivity having a peak in the front direction of the liquid crystal panel 10. .

As will be described later with reference to FIG. 6, etc., in the light guide plate 80, a plurality of grooves 86 including linear fine recesses extending in the X-axis direction are formed as a diffusion pattern on the bottom surface 80c where the reflection sheet 187 is located. . In this form, the density of the grooves 86 increases as the distance from the light emitting element 89 increases. Therefore, the intensity distribution of the illumination light emitted from the light guide plate 80 becomes uniform regardless of the distance from the light emitting element 89 .

The bottom plate portion 45 of the first frame 40 is partially formed between the bottom surface 80c of the light guide plate 80 and the first frame 40 in a region overlapping with the side end surface (side surface) 801 of the light guide plate 80 so that a gap can be ensured. The steps are bent toward the light guide plate 80 . Thereby, the reflective sheet 187 and the lower plate portion 61 of the light source supporting member 60 can be sandwiched between the bottom surface 80 c of the light guide plate 80 and the bottom plate portion 45 in the gap. In addition, since the bottom plate portion 45 of the first frame 40 is partially bent toward the light guide plate 80 to form a concave portion on the back side of the first frame 40, the flexible wiring board 200 is bent and extended to the bottom plate portion 45 of the first frame 40. The circuit board 250 is disposed within the depth of the recess in such a recess. Therefore, it is possible to reduce the thickness of the lighting device 8 .

In this embodiment, the light source substrate 88 is arranged such that one surface 881 on which the light emitting element 89 is mounted faces the light incident portion 80 a of the light guide plate 80 . Further, the light source substrate 88 has a structure in which a wiring pattern and/or land are provided along with an insulating layer on one surface 881 of a plate-like metal plate 887 (support plate) extending along the light incident portion 80a. Such a configuration can be realized by bonding a flexible wiring board 888 on which a resin base layer, a wiring pattern, an insulating protective layer, etc. are laminated in this order to one surface 881 of a metal plate 887 . Accordingly, the joint portion where the wiring pattern and the chip of the light emitting element 89 are mounted is electrically insulated from the metal plate 887 . In this embodiment, the metal plate 887 includes an aluminum plate, and the metal plate 887 ensures the mechanical strength of the light source substrate 88 and also functions as a heat sink for heat generated from the light emitting element 89 .

As shown in FIG. 3 , FIG. 4 and FIG. 5 , on the other side of the surface 882 of the two light source substrates 88 , the light source supporting members 60 holding the light source substrates 88 are arranged respectively, and the light source supporting members 60 are arranged It is held between the first frame 40 and the second frame 30 . In this embodiment, the light source supporting member 60 is a rod-shaped metal part extending along the other surface 882 of the light source substrate 88 . The light source support member 60 has a lower plate portion 61 overlapping the bottom plate portion 45 of the first frame 40 and a substrate support plate portion 62 constituting a wall surface protruding upward from a midway position in the width direction of the lower plate portion 61 . In addition, the light source support member 60 has an upper plate portion 63 bent from the substrate support plate portion 62 to the side opposite to the side where the light guide plate 80 is located on the upper end side (opposite side to the lower plate portion 61 ) of the substrate support plate portion 62 , The plate portion 63 is fixed to at least one of the upper plate portion 55 of the third frame 50 and the upper plate portions 315 and 325 of the second frame 30 with screws or the like.

In the light source supporting member 60 having such a configuration, the surface of the substrate supporting plate portion 62 on the side where the light guide plate 80 is located serves as the substrate holding surface 620 for holding the light source substrate 88 . In this embodiment, the light source substrate 88 is fixed to the substrate holding surface 620 by the screws 69 and the like that are stopped from the other surface 882 , and the screws 69 are not exposed on the one surface 881 of the light source substrate 88 . In this state, the entire surface of the other surface 882 (metal plate 887 ) of the light source substrate 88 is in contact with the substrate holding surface 620 and overlapped in close contact. In addition, the light source supporting member 60 is made of metal such as aluminum and/or ferrous metal. Therefore, the heat generated by the light emitting element 89 is transferred from the metal plate 887 of the light source substrate 88 to the light source supporting member 60 , and the heat of the light source supporting member 60 is transferred to the first frame 40 . Therefore, the temperature rise of the light emitting element 89 can be suppressed low.

Here, although most of the light emitting elements 89 are arranged at the _first interval S1, the plurality of locations where the screws 69 are arranged are all locations where the light emitting elements 89 are arranged at the _second interval S2 wider than the _first interval S1. Therefore, when light is emitted from the light-emitting element 89, the portion of the _second space S2 has a lower emission intensity of light than the portion of the _first space S1. Therefore, in this embodiment, the light guide plate 80 has the configuration described below with reference to FIG. 6 .

(consisting of light guide plate 80)

6 is an explanatory view of the light guide plate 80 used in the lighting device 8 of the liquid crystal display device 100 according to Embodiment 1 of the present invention. FIGS. It is a bottom view showing an enlarged second diffusion region of the light guide plate 80 . FIG. 7 is an explanatory diagram of the groove 86 shown in FIG. 6, and FIG. Illustrating.

As shown in FIG. 6, the central region of the bottom surface 80c of the light guide plate 80 (the region corresponding to the image display region 100a of the liquid crystal panel 10) becomes the first diffusion region 80s in which a plurality of grooves 86 are formed. Between the region 80s and the end of the light guide plate 80 is an outer edge region 80t. The first diffusion region 80 s is a region from which illumination light is emitted, and overlaps with the image display region 100 a of the liquid crystal panel 10 . In the first diffusion region 80s, the plurality of grooves 86 are arranged such that the groove rows 860 arranged in a straight line (on the extension line) in the X-axis direction are arranged in parallel in the Y-axis direction. In this mode, the grooves 86 The grooves are arranged at equal intervals in the groove row 860 .

Furthermore, in the bottom surface 80c of the light guide plate 80 of this embodiment, the second diffusion region 80u in which the groove 86 is partially formed (a part of the region) is provided in the outer edge region 80t. More specifically, in the illuminating device 8 of this form, there are discontinuous parts where the plurality of light emitting elements 89 arranged in the X-axis direction are not arranged at the same interval or at the same pitch. The portion (second interval S ₂ ) where the interval between light emitting elements 89 becomes wider than the interval between other light emitting elements 89 (first interval S ₁ ) is wider than the interval between other light emitting elements 89 (second interval S ₂ ). A rectangular second diffusion region 80u in which a plurality of grooves 86 are formed is provided between the portion and the first diffusion region 80s. That is, the light incident portion _{80a (} A rectangular second diffusion region 80 u in which a plurality of grooves 86 are formed is provided between the side end surfaces/side surfaces (801 , 802 ) and the first diffusion region 80 s. Here, the dimension W of the second diffusion region 80u in which the plurality of grooves 86 are formed in the direction in which the light emitting elements 89 are arranged is smaller than the second interval S ₂ . In addition, in the second diffusion area 80u, the plurality of grooves 86 are arranged on the same extension line in the longitudinal direction toward the X-axis direction to form a groove row, similarly to the grooves 86 of the first diffusion area 80s. A plurality of rows of grooves are arranged side by side in the Y-axis direction.

As shown in FIG. 7( a ), the groove 86 includes a concave portion that is depressed on the bottom surface 80 c of the light guide plate 80 ; as shown in FIG. 7( b ), the groove 86 has a planar shape with the longitudinal direction facing the X-axis direction. It is oblong groove-shaped. The YZ cross-section of the groove 86 in FIG. 7( a ) is basically a prism shape (semicircle or parabola), and the inner bottom corresponding to the top is a semicircle with a curvature radius of about 30 μm to 80 μm. The opening width of the groove 86 is, for example, 100 μm to 300 μm, and the depth (dimension in the Z-axis direction) of the groove 86 is, for example, 100 μm to 700 μm.

In the illuminating device 8 configured in this way, the light emitted from the light emitting element 89 is repeatedly transmitted in the light guide plate 80 after being incident from the light incident portion 80a as indicated by the arrow L1. The light exit surface 80b/second main surface and/or the bottom surface 80c/first main surface travels inside the light guide plate 80 while undergoing total reflection. And as shown by arrow L2, it is reflected by the groove|channel 86, and as shown by arrow L3, it emits as illumination light from the light emission surface 80b/2nd main surface. At this time, the light reflected by the end of the groove 86 travels in various directions through diffusion and propagation, and the uniformity of the illumination light emitted from the light emitting surface 80b/second main surface of the light guide plate 80 is improved.

Here, when the light emitted from the light-emitting elements 89 enters the light guide plate 80, the portion (the portion of the _second interval S2) where the interval between the light-emitting elements 89 is wider than other portions becomes a discontinuous portion in which the light intensity is lower than that of the surrounding area. , but if the light is incident on the second diffusion region 80u corresponding to (opposed to) the _second space S2 in the light guide plate 80, it will be diffused by the plurality of grooves 86 provided in the second diffusion region 80u. The reflection is incident on the first diffusion area 80s. Therefore, even in the portion where the interval between the light emitting elements 89 is the _second interval S2, since the formation of the groove 86 compensates for the light diffusing property, the difference in light intensity with the surroundings is alleviated. Therefore, even in the case where there are portions where the interval between the light emitting elements 89 is wide, the light intensity of the illumination light emitted from the light guide plate 80 can be made uniform.

(Manufacturing method of light guide plate 80 )

FIG. 8 is an explanatory view showing a method of manufacturing the light guide plate 80 shown in FIG. 6 .

When manufacturing the light guide plate 80 described with reference to FIGS. 6 and 7 , as shown in FIG. 8 , after forming the resin plate 80w for the light guide plate by extrusion molding and/or injection molding, one side of the resin plate 80w is The resin plate 80 is placed on an XY stage (not shown) so that the surface (the bottom surface 80 c of the light guide plate 80 ) faces upward. Then, the resin plate 80 is irradiated with the laser beam La of a carbon dioxide laser and/or a femto (femto) second laser, and the polymer material constituting the resin plate 80w is melted and volatilized at the irradiated position to form the groove 86 . In this form, four laser beams La are generated from the laser beam emitted from the laser device.

In addition, in this embodiment, by turning on and off the four laser beams La at predetermined timings, and moving the resin plate 80w in the X-axis direction, the irradiation position of the laser beam La is moved in the X-axis direction, Four groove rows 860 are formed at the same time. Then, after forming four rows of groove rows 860, the resin plate 80w is moved in the Y-axis direction, and is reset at a position on one side Y1 of the previously formed four rows of groove rows 860 in the Y-axis direction. Four groove rows 860 are formed. By repeating such steps, grooves 86 are formed in the entire first diffusion region 80s. At this time, if the amount of movement is adjusted in the Y-axis direction of the resin plate 80w, the grooves 86 can be formed at a predetermined density.

When the light guide plate 80 is produced by such a method, in this form, in the outer edge region _80t , as shown in FIG. La, grooves 86 are also formed in the outer edge region 80t to provide a rectangular second diffusion region 80u.

(The main effect of this method)

As described above, in the light guide plate 80 used in the liquid crystal display device 100 and the lighting device 8 of this embodiment, the first diffusion region 80s formed with a plurality of grooves 86 (first diffusion pattern) and the In the outer edge region 80t of the end portion of the light guide plate 80, a rectangular second diffusion region 80u formed with grooves 86 is provided opposite to a portion where the interval between the light emitting elements 89 is the _second interval S2. Therefore, when the light emitted from the light-emitting elements 89 is incident on the light guide plate 80, the portion where the interval between the light-emitting elements 89 is wider than other portions becomes a discontinuous portion with lower light intensity than the surrounding areas, but when the light is incident on the first In the case of the diffusion area 80s, even in the part where the distance between the light emitting elements 89 is wider than other parts, the groove 86 (second diffusion pattern) formed in the second diffusion area 80u moderates the light from the surrounding area. difference in intensity. Therefore, even if there is a portion where the distance between the light emitting elements 89 becomes wider, the uniformity of the emission intensity of the illumination light from the light guide plate 80 can be improved. In addition, in the outer edge region 80t, the groove 86 is not formed in the region other than the second diffusion region 80u, and the width dimension (the length in the direction in which a plurality of light emitting elements are arranged) w of the second diffusion region 80u is smaller than that of the second diffusion region 80u. interval S ₂ . Therefore, in the outer edge region 80t, diffuse reflection occurs only in the necessary minimum region. Therefore, emission of illumination light or the like from unnecessary portions of the light guide plate 80 does not occur.

In addition, in the first diffusion area 80s, the groove row 860 having the grooves 86 arranged linearly in the X-axis direction is provided so that a plurality of rows are parallel in the Y-axis direction, and the grooves in the second diffusion area 80u are arranged in parallel. 86 is formed so that the longitudinal direction faces the X-axis direction. Therefore, the grooves 86 can be provided in the second diffusion region 80u in the same manner as the method of providing the grooves 86 in the first diffusion region 80s. Furthermore, since the groove 86 is formed by irradiation of the laser beam La, the groove 86 can be easily formed at a predetermined position (second diffusion region 80u) of the outer edge region 80t.

Embodiment 2

9 is an explanatory diagram of a light guide plate 80 used in the lighting device 8 of the liquid crystal display device 100 according to Embodiment 2 of the present invention. In addition, since the basic configuration of this embodiment is the same as that of Embodiment 1, the same reference numerals are attached to the same parts, and their descriptions are omitted. In addition, in FIG. 9 , illustration of the groove 86 of the first diffusion region 80 s is omitted.

As shown in FIG. 9 , in this mode, as in Embodiment 1, also in the bottom surface 80c of the light guide plate 80, in the outer edge region 80t, at the _second interval S2 of the light emitting element 89 wide and the first diffuser. Between the regions 80s, a second diffusion region 80u in which grooves 86 are formed is provided. Furthermore, the width dimension (length in the direction in which the plurality of light emitting elements are arranged) of the second diffusion region 80u is smaller than the second interval S ₂ .

Here, the head 690 of the screw 69 for fixing the light source substrate 88 is exposed or protrudes as a structure from one surface 881 of the light source substrate 88 . In such a portion where the head 690 of the screw 69 exists, the intensity of the light becomes high by the amount of reflection, and it acts as if a minute light emitting element is virtually arranged. Therefore, in this embodiment, the portion 865 facing the end of the screw 69 on the head 690 side (portion where the screw 69 is exposed) in the second diffusion region 80u is located closer to the first diffusion region 80s than the other portion 866. . That is to say, in the second diffusion area 80u of the light guide plate 80, at the position facing the head 690 of the screw 69 (the part where the screw 69 is exposed), the groove 86 is larger than other areas in the second diffusion area 80u. Formed less, the formation density of the grooves 86 in the Y direction is lower than that of other regions. More specifically, in the second diffusion region 80 u of the light guide plate 80 , a portion where the groove 86 is partially not formed is provided at a portion facing the head 690 of the screw 69 (the portion where the screw 69 is exposed). In this way, in this form, at the portion of the light guide plate facing the head 690 of the screw 69 (the part where the screw 69 is exposed), the end portion of the second diffusion area 80u retreats to the side of the first diffusion area 80s, Therefore, even if the head 690 of the screw 69 is exposed, the difference in light intensity from the surroundings can be effectively alleviated.

Embodiment 3

10 is an explanatory view of the light guide plate 80 used in the lighting device 8 of the liquid crystal display device 100 according to Embodiment 3 of the present invention. FIGS. An explanatory diagram of a configuration example and an explanatory diagram showing a configuration example in which the second diffusion region 80u is formed into a triangular shape or a trapezoidal shape. In addition, since the basic configuration of this embodiment is the same as that of Embodiment 1, the same reference numerals are attached to the same parts, and their descriptions are omitted. In addition, in FIG. 10 , illustration of the groove 86 of the first diffusion region 80 s is omitted.

As shown in FIG. 10 , in this mode, as in Embodiment 1, also in the bottom surface 80c of the light guide plate 80, in the outer edge region 80t, at the _second space S2 wide of the light emitting element 89 and the first diffuser. Between the diffusing regions 80s, a second diffusing region 80u in which grooves 86 are formed is provided. Furthermore, the width dimension (length in the direction in which the plurality of light emitting elements are arranged) of the second diffusion region 80u is smaller than the second interval S ₂ .

As such a second diffusion region 80u, although the rectangular second diffusion region 80u is formed in Embodiment 1, the second diffusion region 80u shown in FIG. 80s semicircle shape. In addition, the second diffusion region 80 u shown in FIG. 10( b ) has a trapezoidal or triangular shape whose base faces the first diffusion region 80 s. That is to say, all of the above are set so that the formation of the groove 86 gradually decreases as the approach to the light incident portion 80a (side end surface/side surface 802 ) decreases. Inside, the outer edge of the region (an imaginary outline of the region) constitutes the top. According to such a configuration, the width dimension (length in the direction in which the plurality of light emitting elements are arranged) W of the second diffusion region 80 u is wider on the side of the first diffusion region 80 s and narrower on the side of the light incident portion 80 a. Therefore, in the second diffusion region 80u, the diffusion of light on the side of the light incident portion 80a is kept low, while sufficient diffusion of light can be performed at a position close to the first diffusion region 80s. Therefore, when light is incident on the first diffusion region 80s, even at a portion where the distance between the light emitting elements 89 is wider than other portions, the difference in light intensity from the surroundings can be effectively alleviated.

other implementations

In Embodiments 1 to 3 above, grooves 86 (linear grooves) were provided as diffusion patterns, but white dots and/or tiny prism-shaped protrusions may be used as diffusion patterns in the light guide plate. 80 application of the present invention.

In Embodiments 1 to 3 above, the position of the set screw 69 is the second space S ₂ , but for example, when a plurality of light source substrates 88 are used, it is also possible to place them between the adjacent light source substrates 88 . The present invention is applied when the interval between the light emitting elements 89 is the _second interval S2.

In Embodiments 1 to 3 above, both the side end surface (side surface) 801 side of the light guide plate 80 and the side end surface 802 side of the light guide plate 80 are used as the light incident portion 80a, but the side end surface (side surface) 801, The present invention is applied to the liquid crystal display device 100 in which only one of 802 becomes the light incident portion 80a.

In Embodiments 1 to 3, the one surface 881 of the light source substrate 88 faces the light incident portion 80a of the light guide plate 80, but one surface 881 of the light source substrate 88 may be perpendicular to The present invention is applied to the liquid crystal display device 100 having the configuration of the light incident portion 80 a of the light guide plate 80 .

(Example of mounting to electronic equipment)

In the above-mentioned embodiment, a liquid crystal television was exemplified as the electronic device 2000 equipped with the liquid crystal display device 100, but other than the liquid crystal television, it may also be used in a monitor of a personal computer, a digital signage, a car navigation device, a portable The liquid crystal display device 100 to which the present invention is applied is used as a display unit of electronic equipment such as an information terminal.

Claims (10)

1. an illuminator, it is characterised in that have:

Light guide plate, it possesses the 1st interarea 2nd interarea opposed with described 1st interarea and multiple side Face, and

Multiple light-emitting components, it is along the 1st side arrangement among the plurality of side；

At the 1st interarea of described light guide plate, the 1st diffusion area being formed with the 1st diffusion figure is set And the outer edge area being configured between the 1st diffusion area and described 1st side；

Multiple light-emitting components include the 1st light-emitting component, the 2nd light-emitting component and the 3rd light-emitting component, Between described 1st light-emitting component and described 2nd light-emitting component, the 1st interval is set, the described 2nd Between light-emitting component and described 3rd light-emitting component, 2nd interval wider than described 1st interval is set；

Only in the described outer edge area of the position corresponding to being provided with described 2nd interval, setting is formed 2nd diffusion area of the 2nd diffusion figure；

The length of described 2nd diffusion area on the direction of the plurality of light-emitting component arrangement is set as, Narrower than described 2nd interval.

Illuminator the most according to claim 1, it is characterised in that:

2nd interarea of described light guide plate becomes light-emitting face.

Illuminator the most according to claim 2, it is characterised in that:

Described 1st diffusion figure and described 2nd diffusion figure are groove；

In described 1st diffusion area, direction intersects in the face with the 1st diffusion area The described 1st multiple described groove arrangement in direction among 1 direction and the 2nd direction is the groove of linearity It is listed in multiple row on described 2nd direction parallel；

Described in described 2nd diffusion area, groove type becomes, and makes length direction towards described 1st side To.

Illuminator the most according to claim 3, it is characterised in that:

Described light guide plate is by laser beam irradiation is formed described groove in resin plate.

Illuminator the most according to claim 1 and 2, it is characterised in that:

Described 2nd diffusion area is rectangular shape.

Illuminator the most according to claim 1 and 2, it is characterised in that:

The plurality of light-emitting component is arranged at the side, face of a side of light source substrate；

At the position at described 2nd interval, there is the face protruding from one from described light source substrate The structure of side；

The part being opposite to described structure of the end on the described structure side of described 2nd diffusion area It is positioned at than other parts of described end by described 1st diffusion area side.

Illuminator the most according to claim 1 and 2, it is characterised in that:

Described 2nd diffusion area is to make string towards the semi-circular shape of described 1st diffusion area.

Illuminator the most according to claim 1 and 2, it is characterised in that:

Described 2nd diffusion area is to make base towards the trapezoidal or triangle of described 1st diffusion area Shape.

9. a liquid crystal indicator, it is characterised in that:

Possesses the illuminator according to any one of claim 1～8；

Possess and overlap in the liquid crystal panel of described 2nd interarea of described light guide plate.

10. an electronic equipment, it is characterised in that:

Possesses the liquid crystal indicator described in claim 9.