阅读说明：本技术 照明装置以及显示装置 (Illumination device and display device ) 是由 高桥伸行 于 2018-06-15 设计创作，主要内容包括：照明装置(12)包括：光源列(170),其由多个第一光源(171)构成,多个第一光源分别向相同方向发光,并且彼此之间保持间隔且排列成列状；导光构件(19),其具有：光入射面(191c),其与第一发光部(172a)相对,并入射来自第一发光部(172a)的光；导光主体部(191),其为具有光出射面(191a)的板状,将从光入射面(191c)入射至内部的光向外部出射；以及延伸设置部(192),其为板状并以从表面侧覆盖光源列(170)的方式从导光主体部(191)的端面(191c)的一部分向外侧延伸,并且延伸设置部(192)的厚度比导光主体部(191)的厚度薄；以及多个第二光源(172),其以与光源列(170)一同排列成列状并由延伸设置部(192)覆盖的方式配置于光源列的左右邻,并且具有向延伸设置部(192)发光的第二发光部(172a)。(The lighting device (12) comprises: a light source array (170) which is composed of a plurality of first light sources (171) that emit light in the same direction, and are arranged in a row with a space therebetween; a light guide member (19) having: a light incident surface (191c) that faces the first light emitting section (172a) and that receives light from the first light emitting section (172 a); a light guide body (191) having a plate shape with a light emitting surface (191a) and emitting light entering the inside from a light incident surface (191c) to the outside; and an extension unit (192) that is plate-shaped and extends outward from a part of the end surface (191c) of the light guide main body unit (191) so as to cover the light source row (170) from the front surface side, and the thickness of the extension unit (192) is thinner than the thickness of the light guide main body unit (191); and a plurality of second light sources (172) which are arranged adjacent to each other on the left and right sides of the light source row (170) so as to be arranged in a row together with the light source row and covered with the extension sections (192), and which have second light emitting sections (172a) that emit light to the extension sections (192).)

1. An illumination device, comprising:

a light source array including a plurality of first light sources, each of the plurality of first light sources having a first light emitting portion emitting light in the same direction, the plurality of first light sources being arranged in a row with a space therebetween;

a light guide member having: a light incident surface which is formed of an end surface facing the first light emitting portion and which receives light from the first light emitting portion; a light guide body portion having a plate shape with a light emitting surface which is formed by a plate surface on the front surface side and emits light incident from the light incident surface to the inside to the outside; and an extension portion that is plate-shaped and extends outward from a part of the end surface of the light guide main body portion so as to cover the light source row from a front surface side, and that has a thickness smaller than that of the light guide main body portion; and

and a plurality of second light sources which are arranged adjacent to each other on the left and right sides of the light source row so as to be arranged in a row together with the light source row and covered by the extension portions, and which have second light emitting portions that emit light toward the extension portions.

2. A lighting device as recited in claim 1, comprising:

and one or more third light sources that are arranged between the adjacent first light sources constituting the light source array and that have third light emitting portions that emit light toward the extension portions.

3. A lighting device as recited in claim 1, comprising:

a first providing unit that provides driving power to the first light source; and

and a second supply unit that supplies drive power to the second light source so that the second light source is driven to be turned on independently of the first light source.

4. The lighting device of claim 2,

a first providing unit that provides driving power to the first light source; and

and a third supply unit configured to supply driving power to the second light source and/or the third light source so that the second light source and/or the third light source is driven to be turned on independently of the first light source.

5. A lighting device as recited in any one of claims 1-4, comprising:

and a light reflection member having light reflectivity, and disposed on at least a portion of the surface on the front surface side of the extension portion, the portion overlapping with the second light emitting portion in a plan view.

6. A display device, comprising:

the lighting device of any one of claims 1 to 5; and

a display panel displaying an image using the light irradiated from the illumination device.

Technical Field

The present invention relates to an illumination device and a display device.

Background

The liquid crystal display device has an illumination device (backlight device) that supplies light to the liquid crystal panel in the same direction as the liquid crystal panel. As such an illumination device, a so-called edge-light (or side-light) illumination device is known, in which a plurality of leds (light Emitting diodes) are arranged in a row so as to face an end surface of a light guide plate. Such an illumination device is disposed on the back surface side of the liquid crystal panel, and supplies light diverged in a planar manner to the back surface of the liquid crystal panel.

In an edge-emitting type lighting device using LEDs, the brightness in the vicinity of the corner of the light guide plate tends to be reduced. The reason is that since light emitted from the LED has a predetermined divergence angle (directivity), it is difficult to provide light if a corner portion of the light guide plate is disposed at a dark portion outside the diverged light. Here, as shown in patent document 1, for example, in order to suppress a decrease in luminance near the corner of the light guide plate, there is provided an illumination device in which light from an LED is directly incident from the corner of the light guide plate. In this lighting device, two inclined end surfaces that are arranged at both ends of the end surface (i.e., corners of the light guide plate) and inclined with respect to the end surface, except for the end surface along one side of the light guide plate, are light incident surfaces on which light from the LED is incident. Therefore, the LED is disposed so as to face the inclined end face disposed at the corner of the light guide plate.

Disclosure of Invention

Technical problem to be solved by the invention

In the lighting device, the portion where the LEDs are arranged must correspond to the non-display region arranged around the display region of the liquid crystal panel. Therefore, if the LEDs are arranged to face the corners of the light guide plate as described above, the portion corresponding to the non-display region becomes large. In particular, if a rectangular display region is set, the width of the non-display region surrounding the display region becomes large, and it is not possible to realize a so-called narrow frame.

Means for solving the problems

An object of the present invention is to provide an illumination device capable of narrowing a portion of a display panel corresponding to a non-display region and suppressing a decrease in luminance at an end side of a light source column.

The lighting device according to the present invention includes: a light source array including a plurality of first light sources, each of the plurality of first light sources having a first light emitting portion emitting light in the same direction, the plurality of first light sources being arranged in a row with a space therebetween; a light guide member having: a light incident surface which is formed of an end surface facing the first light emitting portion and which receives light from the first light emitting portion; a light guide body portion having a plate shape with a light emitting surface which is formed by a plate surface on the front surface side and emits light incident from the light incident surface to the inside to the outside; and an extension portion that is plate-shaped and extends outward from a part of the end surface of the light guide main body portion so as to cover the light source row from a front surface side, and that has a thickness smaller than that of the light guide main body portion; and a plurality of second light sources which are arranged adjacent to each other on the left and right sides of the light source row so as to be arranged in a row together with the light source row and covered by the extension portions, and which have second light emitting portions that emit light toward the extension portions.

Effects of the invention

According to the present invention, it is possible to provide an illumination device capable of narrowing a portion of a display panel corresponding to a non-display region and suppressing a decrease in luminance at an end side of a light source column.

Drawings

Fig. 1 is a plan view of a liquid crystal display device according to embodiment 1 of the present invention.

Fig. 2 is a cross-sectional view of the liquid crystal display device taken along line a-a of fig. 1.

Fig. 3 is a cross-sectional view of the liquid crystal display device taken along line B-B of fig. 1.

Fig. 4 is a plan view showing the arrangement relationship between the light guide member and the LEDs (first LEDs and second LEDs) provided in the illumination device according to embodiment 1.

Fig. 5 is a plan view showing an arrangement relationship between the light guide plate and the LEDs (first LEDs) included in the illumination device of comparative example 1.

Fig. 6 is a graph showing the luminance of the illumination device of embodiment 1 and the luminance of the illumination device of comparative example 1.

Fig. 7 is a plan view showing the arrangement relationship between the light guide member and the LEDs (the first LED, the second LED, and the third LED) provided in the illumination device according to embodiment 2.

Fig. 8 is a plan view showing an arrangement relationship between the light guide plate and the LEDs (first LEDs) included in the illumination device of comparative example 2.

Fig. 9 is a graph showing the luminance of the illumination device of embodiment 2 and the luminance of the illumination device of comparative example 2.

Fig. 10 is a sectional view of a liquid crystal display device of embodiment 3.

Detailed Description

< embodiment 1 >

Next, a liquid crystal display device 10 including an illumination device 12 according to embodiment 1 of the present invention will be described with reference to fig. 1 to 6. Also, in each drawing, an X axis, a Y axis, and a Z axis are shown for convenience of explanation. Fig. 1 is a plan view of a liquid crystal display device 10 according to embodiment 1 of the present invention, fig. 2 is a cross-sectional view of the liquid crystal display device 10 taken along line a-a of fig. 1, fig. 3 is a cross-sectional view of the liquid crystal display device 10 taken along line B-B of fig. 1, and fig. 4 is a plan view showing a positional relationship between a light guide member and LEDs included in an illumination device 12 according to embodiment 1. As shown in fig. 1, the liquid crystal display device 10 as a whole has a horizontally long rectangle extending in the left-right direction (X-axis direction) longer than in the up-down direction (Y-axis direction).

The liquid crystal display device 10 mainly includes a liquid crystal panel 11 serving as a display panel, an illumination device (backlight device) 12 serving as an external light source for supplying light to the liquid crystal panel 11, a frame-shaped bezel 13 for holding the liquid crystal panel 11, the illumination device 12, and the like.

The liquid crystal panel 11 is mainly composed of a pair of transparent substrates and a liquid crystal layer sealed so as to be sandwiched between the pair of transparent substrates, and displays an image in a visible state on the display surface 11a by light emitted from the illumination device 12. The liquid crystal panel 11 has a rectangular shape which is horizontally long as a whole in a plan view. One of the pair of substrates constituting the liquid crystal panel 11 is an array substrate, and is configured by a structure in which tfts (thin film transistors), pixel electrodes, and the like as switching elements are arranged in a matrix on a transparent glass substrate. The other substrate is a color filter (hereinafter, CF) substrate, and color filters of red, green, and blue colors are arranged in a matrix on a transparent glass substrate.

The liquid crystal panel 11 has a display area AA for displaying an image on the center side of the display surface 11 a. The display area AA is a horizontally long rectangle in plan view, and a frame-shaped (frame-shaped) non-display area NAA is provided on the peripheral edge side of the display surface 11a so as to surround the display area AA.

The illumination device 12 is a device that is disposed on the rear surface 11b side of the liquid crystal panel 11 and supplies light to the liquid crystal panel 11, and is configured to emit white light that diverges in a planar manner. As shown in fig. 2 to 4, the illumination device 12 is one of edge light type (side light type), and mainly includes a housing 14, an optical sheet 15, a frame 16, a first LED (first light source) 171, a second LED (second light source) 172, an LED substrate 18, a light guide member 19, a reflection sheet 20, and the like.

The casing 14 is formed in a substantially box shape with a shallow bottom opening on the surface side as a whole, and is formed of a metal plate such as an aluminum plate or a galvanized steel Sheet (SECC). The case 14 has a plate-like bottom portion 14a having a substantially rectangular shape in plan view, similar to the liquid crystal panel 11 and the like, and a plate-like side wall portion 14b rising from a peripheral edge of the bottom portion 14a and surrounding the bottom portion 14 a.

Various members such as the LED substrate 18 on which the first LED171 and the second LED172 are mounted, the reflective sheet 20, the light guide member 19, and the optical sheet 15 are housed inside the housing 14. Substrates such as a control substrate and an LED driving substrate 25 are mounted on the outer side of the housing 14.

In the case 14, a reflection sheet 20 is disposed so as to cover the surface of the bottom portion 14 a. The reflecting sheet 20 is a sheet-like member having light reflectivity, and is made of, for example, white foamed polyethylene terephthalate (an example of a white plastic sheet). Further, a light guide member 19 is housed in the case 14 so as to be mounted on the reflection sheet 20.

The light guide member 19 is made of a synthetic resin material (for example, acrylic resin such as PMMA, polycarbonate resin) having a refractive index much higher than that of air and excellent transparency. The light guide member 19 is a substantially plate-shaped member as a whole, and has a rectangular shape in a plan view. Specifically, the light guide member 19 has: a plate-shaped light guide body 191 having a predetermined thickness that occupies most of the light guide member 19, and an extension 192 that is thinner than the light guide body 191, has a plate shape, and is extended at an end of the light guide body 191. The extension portion 192 is extended from one end of the long side of the light guide body 191. The front surface side plate surface 191a of the light guide body 191 and the front surface side plate surface 192a of the extension 192 are connected as one plate surface. That is, the light guide member 19 is formed in a shape in which an end portion corresponding to one side of the plate material is cut from the back surface side. In this specification, the front surface 19a of the light guide member 19 is composed of the plate 191a of the light guide body 191 and the plate 192a of the extension 192, and the rear surface 19b of the light guide member 19 is composed of only the rear surface 191b of the light guide body 191. Such a light guide member 19 is housed in the case 14 such that the front surface side plate surface 19a faces the back surface 11b side of the liquid crystal panel 11 and the back surface side plate surface 19b faces the reflection sheet 20.

Most of the plate surface 191a of the light guide body 191 on the front surface side of the plate surface 19a of the light guide member 19 overlaps the display region AA of the liquid crystal panel 11 in a plan view. The frame-shaped peripheral edge area of the plate surface 191a is very narrow, but overlaps the non-display area NAA. On the other hand, the plate surface 192a of the extension portion 192 does not overlap the display region AA of the liquid crystal panel 11 in plan view, but overlaps only the non-display region NAA. Therefore, only the front surface side plate surface 191a of the light guide body 191 among the front surface side plate surfaces 19a of the light guide member 19 may be the light emitting surface 191a that emits light to the liquid crystal panel 11 side.

The optical sheet 15 is disposed between the light output surface 191a and the liquid crystal panel 11 in a state of being mounted on the frame 16. Of the four end surfaces of the light guide body 191, the end surface 191c of the portion provided with the extended portion 192 faces the plurality of first LEDs 171 arranged in a row, and serves as a light incident surface (first light incident surface) 191c on which light from the first LEDs 171 enters. The light incident surface (first light incident surface) 191c faces the first light emitting portion 171a of the first LED 171. An end surface 191d of the light guide body 191 on the opposite side of the light incident surface 191c faces the side wall portion 14b in the housing 14.

The rear surface side plate surface 192b of the extension portion 192 faces the light emitting surface (second light emitting portion) 172a of the second LED172, and serves as a light incident surface (second light incident surface) 192b on which light from the light emitting surface (second light emitting portion) 172a can be incident.

A light reflection/scattering pattern having a function of reflecting or scattering light entering the light guide member 19 from the light incident surface 191c and the light incident surface 192b and rising toward the light emitting surface 191a is formed on the plate surface 19b on the back surface side of the light guide member 19 (the plate surface 191b of the light guide body 191). The light reflection/scattering pattern is formed of, for example, a plurality of white coating films printed in dots.

The frame 16 has a frame shape (frame shape) covering the peripheral end of the light guide member 19 from the front surface side as a whole, and is attached to the opening portion of the housing 14 from the front surface side. The frame 16 is made of, for example, a synthetic resin molded product. The frame 16 has: a frame body portion 161 which is frame-shaped in a plan view and whose inner peripheral edge side is directed from the front surface side to the peripheral end portion of the light guide member 19 in a state of being housed in the housing 14; and a standing wall portion 162 extending from the frame body portion 161 toward the bottom portion 14a of the case 14 and disposed outside the side wall portion 14b of the case 14.

The frame body 161 is formed into a frame shape having a predetermined width such that the inner peripheral edge side thereof overlaps the peripheral end portion of the light guide member 19 and the outer peripheral edge side thereof overlaps the upper end portion of the side wall portion 14b of the housing 14. The back surface on the inner peripheral side of the frame body portion 161 is directed from the front surface side to the peripheral end portion of the light guide member 19. The frame-shaped periphery of the plate surface 191a of the light guide body 191 and the plate surface 192a of the extension 192 are covered by the frame body 161. The surface of the frame body 161 on the inner peripheral side is set lower than the surface on the outer peripheral side by one step, and the end of the optical sheet 15 is mounted on the lower portion.

The standing wall portion 162 extends from the back surface of the frame body portion 161 on the outer peripheral edge side toward the bottom portion 14a side of the housing 14, and is formed in a plate shape facing the outer peripheral surface of the side wall portion 14b of the housing 14. The standing wall portion 162 has a frame shape that entirely surrounds the periphery of the side wall portion 14 b.

The optical sheet 15 has a substantially rectangular shape that is horizontally long in a plan view, like the liquid crystal panel 11. The optical sheet 15 is disposed between the light output surface 191a of the light guide member 19 and the back surface 11b of the liquid crystal panel 11 so that the peripheral end portion thereof is mounted on the frame main body portion 161 of the frame 16 from the front surface side. The optical sheet 15 provides a predetermined optical function and has a function of transmitting light emitted from the light guide member 19 toward the liquid crystal panel 11. The optical sheet 15 is formed by laminating a plurality of sheets. Specific examples of the sheet constituting the optical sheet 15 include a diffusion sheet, a lens sheet, and a reflective polarizer. The optical sheet 15 is made of a transparent plastic material.

In order to supply light to the light-guiding member 19, the illumination device 12 has two kinds of light sources. One light source (first light source) is a first LED171 that emits light toward the light incident surface (first light incident surface) 191c of the light guide member 19, and the other light source (second light source) is a second LED172 that emits light toward the plate surface (second light incident surface) 192b on the back surface side of the extended portion 192.

A plurality of first LEDs 171 are used, and the first LEDs 171 are arranged in a row (in the present embodiment, one row) with a space (in the present embodiment, equal space) therebetween, so that the first LEDs 171 emit light in the same direction. As shown in fig. 4, the plurality of first LEDs 171 thus arranged in a column form a light source column 170. The first LEDs 171 forming the light source array 170 are arranged such that the light emitting surfaces (first light emitting portions) 171a face the same direction (i.e., the light incident surface 191c side). The light source column 170 has a length shorter than the light incident surface 191c of the rectangular shape extending in the left-right direction (X-axis direction). The light source array 170 is disposed in the housing 14 so as to face a central portion of the light incident surface 191 c. The first LED171 is a so-called top emission type, and a light emitting surface (first light emitting portion) 171a is surface-mounted on the LED substrate 18 so as to face the LED substrate (light source substrate) 18 side. The first LED171 is mainly configured to include an LED element (an LED chip, a light emitting element) as a light emitting source, a sealing material (a translucent resin material) for sealing the LED element, and a case (a housing, a casing) for housing the LED element and filling the sealing material. Each of the first LEDs 171 of the present embodiment is configured to emit white light. In fig. 2 and the like, the direction of light with the highest emission intensity among the light emitted from the light-emitting surface 171a of the first LED171 is indicated by an optical axis L1. The light emitted from the first LED171 has a predetermined divergence angle, and is schematically shown in a fan shape in fig. 2 and 4. In the present embodiment, the interval between the adjacent first LEDs 171 is set so that a part of the light emitted from each light-emitting surface 171a (light having a predetermined divergence angle expressed in a fan shape in a plan view) overlaps with each other between the adjacent first LEDs 171. In this manner, by setting the interval between the first LEDs 171, the adjacent first LEDs 171 are brought close to each other, thereby preventing a portion (dark portion) with reduced luminance from being formed between the adjacent first LEDs 171.

The second LEDs 172 are arranged adjacent to each other on the left and right sides of the light source array 170 so as to be arranged in a row together with the light source array 170 including the first LEDs 171. That is, the second LEDs 172 are disposed one by one at both ends of the light source array 170 so as to be disposed between the light source arrays 170. The light emitting surface (second light emitting portion) 172a of the second LED172 emits light toward the plate surface (second light incident surface) 192b on the rear surface side of the extended portion 192. The second LED172 is of a so-called side emission type, and a light emitting surface (second light emitting portion) 172a is surface-mounted on the LED board 18 so as to intersect perpendicularly with a surface (mounting surface) of the LED board 18. The second LED172 is mainly configured to include an LED element (LED chip, light emitting element) as a light emitting source, a sealing material (translucent resin material) for sealing the LED element, and a case (housing, casing) for housing the LED element and filling the sealing material, as in the case of the first LED 171. The second LED172 is also configured to emit white light, similarly to the first LED 171. In fig. 3 and the like, a direction in which the light emission intensity is highest among the light emitted from the light-emitting surface 172a of the second LED172 is indicated by an optical axis L2. The light emitted from the second LED172 also has a predetermined divergence angle, and is schematically shown in a fan shape in fig. 3 and 4. The optical axis L2 of the second LED172 is arranged in a direction perpendicular to the optical axis L1 of the first LED 171. As described later, the lighting drive of the second LED172 is controlled independently of the lighting drive of the first LED 171. In the present embodiment, the brightness of the light emitted from the second LED172 is set to be lower than the brightness of the light emitted from the first LED 171.

The LED board (light source board) 18 is in the form of a rectangular (belt-like) elongated and arranged along the light incident surface 191c arranged on the long side of the light guide member 19 (light guide main body 191). In the LED substrate 18, the first LEDs 171 and the second LEDs 172 are mounted on the surface 18a of the LED substrate 18 so as to be arranged in a row (one row) along the longitudinal direction. The LED substrate 18 is attached to the inner wall surface of the side wall portion 14b so as to stand on the bottom portion 14a of the housing 14. A part of the front surface 18a of the LED board 18 faces the end surface of the extended portion 192 of the light guide member 19.

The LED board 18 is configured such that a wiring pattern made of a metal film such as copper foil is formed on the surface of a plate made of an aluminum-based material with an insulating layer interposed therebetween. A white reflective layer may be formed on the outermost surface of the LED substrate 18. The plurality of first LEDs 171 and second LEDs 172 are surface-mounted on the front surface 18a of the LED substrate 18. The first LED171 is electrically connected to a wiring pattern formed in the front surface (mounting surface) 18 a. The second LED172 is electrically connected to a wiring pattern different from the wiring pattern described above so as to be controllable independently of the first LED 171.

On the LED substrate 18, a plurality of first LEDs 171 and a plurality of second LEDs 172 are arranged in a row (one column) with a space therebetween. The LED board 18 is provided with a connection portion to which a wiring member, not shown, is connected, and is supplied with driving power from the LED driving board 25 via the wiring member.

As shown in fig. 2 to 4, the extension portion 192 of the light guide member 19 protrudes outward from a part of the end surface 191c of the light guide body 191 so as to cover the first LED171 (light source row 170) and the second LED172 from the front surface side. In the space formed below the protruding extension 192, the first LED171 and the second LED172 are arranged in a state of being mounted on the LED substrate 18 as described above. The second LEDs 172 are arranged in a row together with the light source row 170, and are covered with the extension portions 192 from the front surface side.

As shown in fig. 4, each of the first LEDs 171 forming the light source array 170 emits light toward the light incident surface 191a extending in the longitudinal direction of the light guide body 191.

In fig. 4, the light emitting surface 191a of the front surface side plate surface 19a of the light guide member 19, which is disposed inside the rectangular frame indicated by the dashed dotted line S, is an area AA corresponding to the display area AA of the liquid crystal panel 11 (an area overlapping the display area AA in a plan view). Further, of the front surface side plate surface 19a of the light guide member 19, the portion (a portion of the light exit surface 191a and the front surface side plate surface 192a of the extension portion 192) disposed outside the frame indicated by the dashed dotted line S is an area NAA corresponding to the non-display area NAA of the liquid crystal panel 11 (an area where the non-display area NAA overlaps in a plan view). The first LED171 and the second LED172 are disposed so as to overlap the region NAA of the light guide member 19 corresponding to the non-display region NAA.

The second LEDs 172 are disposed one by one on the left and right sides of the light source row 170, and are disposed in the vicinity of both ends along the end portion in the longitudinal direction including the light incident surface 191c in the light guide main body portion 191 having a rectangular shape in plan view. That is, the second LEDs 172 are disposed in the vicinity of the corner portions of the light guide body 191 disposed outside the light having a predetermined divergence angle emitted from the adjacent first LEDs 171.

In the area AA of the light guide member 19 (the light exit surface 191a) corresponding to the display area AA, the second LEDs 172 supply light to the corner portions (the corner portions near the light incident surface 191c) AA1, AA2 where the light flux is likely to be insufficient only by the first LEDs 171. As shown in fig. 3 and 4, the light emitting surface (second light emitting portion) 172a of the second LED172 faces the plate surface 192a on the rear surface side of the extended portion 192 with a space therebetween, and light emitted from the light emitting surface 172a is mainly incident from the plate surface (second light incident surface) 192b into the extended portion 192 of the light guide member 19.

In the liquid crystal display device 10 having the above-described configuration, when an image is displayed on the display surface 11a of the liquid crystal panel 11, the first LEDs 171 and the second LEDs 172 of the illumination device 12 emit light. The light from each first LED171 is mainly incident into the light guide body 191 from the light incident surface (first light incident surface) 191 c. The light entering the light guide member 19 (light guide body portion 191) from the light incident surface 191c is reflected by the light reflection/scattering pattern, the reflective sheet 20, and the like provided on the plate surface 19b on the back surface side of the light guide member 19, enters the light guide body portion 191, and is emitted from the light emitting surface 191a as light diverging in a planar shape.

Further, light from each second LED172 enters the extension portion 192 from the plate surface (second light incident surface) 192b on the rear surface side of the extension portion 192. The light incident into the extension portion 192 is reflected by the frame 16 (the frame main body portion 161) covering the front surface side of the extension portion 192, the front surface 18a of the LED substrate 18, and the like, and moves from the extension portion 192 to the light guide main body portion 191 side. The light L21 moving toward the light guide main body 191 is mainly emitted from the corners AA1 and AA2 of the area AA corresponding to the display area AA of the light emitting surface 191 a.

As described above, the corner portions AA1, AA2 of the area AA corresponding to the display area AA among the light output surface 191a of the light guide member 19 are located at positions where the light flux is likely to be insufficient only by the light from the first LED 171. By supplying the light from the second LED172 at such a position, the luminance distribution of the light emitted from the light emitting surface 191a (in particular, the luminance distribution of the light emitted from the area AA corresponding to the display area AA) is uniformized. In this way, the light emitted from the light emitting surface 191a passes through the optical sheet 15, is further uniformly diffused in a planar shape, and is irradiated to the back surface 11b of the liquid crystal panel 11. As a result, the liquid crystal panel 11 can display an image on the display surface 11a by the light from the illumination device 12.

In the illumination device 12 of the present embodiment, since the second LEDs 172 are arranged in a row together with the first LEDs 171 constituting the light source row 170, the second LEDs 172 can be set so as to increase the area of the portion (area AA) corresponding to the display area AA of the liquid crystal panel 11 on the light emitting surface 191a of the light guide member 19 without entering the light emitting surface 191a side. Therefore, the portion (region naa) corresponding to the non-display region can also be narrowed.

In addition, the lighting drive of the second LED172 is controlled independently of the lighting drive of the first LED 171. Specifically, in order to drive the first LED171 to light, drive power (current) is supplied to the first LED171 via a driver (first supply means) 25a on the LED drive board 25, and in order to drive the second LED172 to light, drive power (current) is supplied to the second LED172 from a driver (second supply means) 25b on the other LED drive board 25. Therefore, the luminance of the second LED172 can be independently set lower than the luminance of the first LED171, and for example, the luminance of the second LED172 can be prevented from being excessively high.

Comparative example 1

Here, a comparative example of the illumination device 12 of the present embodiment will be described with reference to fig. 5. Fig. 5 is a plan view showing the arrangement relationship between the light guide plate 19C and the LEDs (first LEDs 171) included in the illumination device of comparative example 1. In the lighting device of comparative example 1, only the first LED171 is used as the LED, and the second LED172 is not provided. In comparative example 1, the light guide plate 19C having the same size as the light guide body portion 191 on which the extension portion 192 is not formed is used instead of the light guide member 19 of embodiment 1. The region inside the rectangular frame indicated by the dashed dotted line S in the light emission surface 19Ca formed by the surface of the light guide plate 19C as in embodiment 1 is a region aa corresponding to the display region of the liquid crystal panel (a region overlapping the display region in a plan view), and the region naa corresponding to the non-display region of the liquid crystal panel (a region overlapping the non-display region in a plan view) is arranged outside the rectangular frame as in embodiment 1.

In comparative example 1, among the first LEDs 171 forming the light source array 170, the dark portions D1, D2 having a lower luminance than the ambient luminance are formed at the outer sides of the first LEDs 171 arranged at both ends. As shown in fig. 5, the light emitted from the first LEDs 171 disposed at both ends has a predetermined divergence angle, and the dark portions D1 and D2 are formed because the light can be provided further outside the divergence angle.

Fig. 6 is a graph showing the luminance of the illumination device 12 of embodiment 1 and the luminance of the illumination device of comparative example 1. The horizontal axis of the graph in fig. 6 indicates the position in the longitudinal direction (X-axis direction) of each light emitting surface 191a, 19Ca in the vicinity of each light incident surface 191C, 19Cc of the light guide member 19 and the light guide plate 19C, and the vertical axis indicates the luminance at the position. As shown in fig. 6, in the illumination device 12 according to embodiment 1, the brightness of the light output surface 191a in the vicinity of the light incident surface 191c of the light guide member 19 is uniform over the entire surface in the longitudinal direction (X-axis direction). In contrast, in the lighting device of comparative example 1, the luminance is lower on both outer sides of the light source row 170 than on the center side.

< embodiment 2 >

Next, an illumination device according to embodiment 2 of the present invention will be described with reference to fig. 7. The lighting device of the present embodiment differs from embodiment 1 in the kind of LEDs used and their arrangement. Fig. 7 is a plan view showing the arrangement relationship between the light guide member 19 and the LEDs (the first LED171, the second LED172, and the third LED172) provided in the illumination device according to embodiment 2. In the lighting device according to embodiment 2, the arrangement positions of the various LEDs are different from those in embodiment 1, but the other basic configurations are the same as those in embodiment 1. As shown in fig. 7, the light guide member 19 used in the present embodiment is the same as embodiment 1, and includes a light guide body 191 and an extension 192. The first LEDs 171 are arranged in a row to form the light source array 170a, as in embodiment 1, but the number of first LEDs 171 forming the light source array 170a is smaller than that in embodiment 1, and the interval between adjacent first LEDs 171 is set to be wider. Further, second LEDs (second light sources) 172 for emitting light to the extended portions 192 are disposed adjacent to the right and left sides of the light source row 170a, as in embodiment 1. Similarly to embodiment 1, the second LEDs 172 of the present embodiment also supply light to the corner portions (corner portions near the light incident surface 191c) aa1 and aa2, in the region aa of the light guide member 19 (light exit surface 191a) corresponding to the display region of the liquid crystal panel, where the light flux tends to be insufficient only by the first LEDs 171.

As described above, since the interval between the adjacent first LEDs 171 of the light source array 170a of the present embodiment is set to be wide, the light emitted from the light emitting surfaces 171a (light having a predetermined divergence angle expressed in a fan shape in plan view) hardly directly overlaps with each other. Therefore, although light emitted from the light emitting surface (first light emitting portion) 171a of each first LED171 enters the light guide member 19 from the light incident surface 191c of the light guide member 19, it is difficult for light from the first LED171 to directly enter the light incident surface 191c of a portion disposed between adjacent first LEDs 171. Therefore, light is difficult to be emitted from the light emitting surface 191a disposed in the vicinity between the adjacent first LEDs 171, which can be said to be an environment where the luminance is easily lower than the ambient luminance. Here, in the present embodiment, it is difficult to supply light from such first LEDs 171, and a third LED (third light source) 173 different from the first LEDs 171 is disposed between the adjacent first LEDs 171. The basic configuration of the third LED173 is the same as that of the second LED172, and the light-emitting surface (third light-emitting portion) 173a thereof faces the plate surface on the back surface side of the extended portion 192 in the same manner as the light-emitting surface (second light-emitting portion) 172a of the second LED 172. In fig. 7, the optical axis of light emitted from the third LED173 is denoted by reference symbol L3.

The lighting drive of the second LED172 and the lighting drive of the third LED173 are controlled independently of the lighting drive of the first LED 171. Specifically, in order to drive the first LED171 to light, driving power (current) is supplied to the first LED171 via a driver (first supply unit) attached to the LED driving board, and in order to drive the second LED172 and the third LED173 to light, driving power (current) is supplied to the second LED172 and the third LED173 via another driver (second supply unit) on the LED driving board. Therefore, the luminance of the second LED172 and the luminance of the third LED173 can be independently set to be lower than the luminance of the first LED171, and for example, the luminance of the second LED172 and the luminance of the third LED173 can be prevented from being excessively high. In another embodiment, the lighting drive of the second LED172 and the lighting drive of the third LED173 may be independently adjusted in luminance.

The corners aa1, aa2 of the region aa (the region inside the rectangular frame indicated by the dashed line S) corresponding to the display region of the liquid crystal panel among the light output surface 191a of the light guide member 19 are at positions where only the light from the first LED171 is likely to be insufficient in luminous flux, as in embodiment 1, and the light from the second LED172 is supplied to such positions, as in embodiment 1. In addition, the edge portions aa3, aa4 of the region aa, which is disposed in the vicinity of the adjacent first LEDs 171, of the light output surface 191a of the light guide member 19 are also located at positions where only the light from the first LEDs 171 and the second LEDs 172 is likely to lack the luminous flux. It is the case of the present embodiment that light from the third LED173 is supplied to such a position. As described above, in the present embodiment, since light is supplied to the corner portions aa1 and aa2 and the edge portions aa3 and aa4, respectively, of the light emitting surface 191a, which are likely to have luminance lower than ambient luminance, the luminance distribution of light emitted from the entire light emitting surface 191a (particularly, the luminance distribution of light emitted from the region aa corresponding to the display region of the liquid crystal panel) is uniformized. As described above, the light emitted from the light emitting surface 191a passes through the optical sheet, is further uniformly diffused in a planar shape, and is incident on the liquid crystal panel, as in embodiment 1.

In the illumination device of the present embodiment, since the second LEDs 172 and the third LEDs 173 are arranged in a line together with the first LEDs 171 that form the light source line 170a, the second LEDs 172 and the second LEDs 173 do not enter the light exit surface 191a side, and the area of a portion (area aa) corresponding to the display area of the liquid crystal panel can be set to be large on the light exit surface 191a of the light guide member 19. Therefore, the portion (region naa) corresponding to the non-display region can also be narrowed.

Comparative example 2

Here, a comparative example of the lighting device of embodiment 2 is described with reference to fig. 8. Fig. 8 is a plan view showing the arrangement relationship between the LED (first LED171) and 19C provided in the illumination device of comparative example 2. In the lighting device of comparative example 2, only the first LED171 is used as the LED, and the second LED172 and the second LED173 are not provided. In comparative example 2, the same light guide plate 19C as in comparative example 1 was used. In fig. 8, a region inside a rectangular frame indicated by a dashed dotted line S in the light emitting surface 19Ca of the plate surface on the front surface side of the light guide plate 19C is a region aa corresponding to a display region of the liquid crystal panel (a region overlapping the display region in a plan view), and a region naa corresponding to a non-display region of the liquid crystal panel (a region overlapping the non-display region in a plan view) is disposed outside the region aa.

In comparative example 2, as in embodiment 2, the interval between adjacent first LEDs 171 is set to be wide. In comparative example 2, the dark portions D11 and D12 having a lower brightness than the ambient brightness are formed outside the first LEDs 171 disposed at both ends. The light emitted from the first LEDs 171 arranged at both ends has a predetermined divergence angle, and it is difficult to supply the light to the outside of the divergence angle, so that the dark portions D11 and D12 as described above are formed.

In addition, dark portions D13 and D14 having lower brightness than the ambient brightness are formed at the edge portions aa3 and aa4 of the region aa, which is disposed in the vicinity of the adjacent first LEDs 171, of the light exit surface 19Ca of the light guide plate 19C. Since the light from the first LEDs 171 is less likely to enter the light incident surface 19Cc disposed in the portion between the adjacent first LEDs 171, the dark portions D13 and D14 as described above are formed.

Fig. 9 is a graph showing the luminance of the illumination device of embodiment 2 and the luminance of the illumination device of comparative example 2. The horizontal axis of the graph in fig. 9 indicates the position in the longitudinal direction (X-axis direction) of each light emitting surface 191a, 19Ca in the vicinity of each light incident surface 191C, 19Cc of the light guide member 19 and the light guide plate 19C, and the vertical axis indicates the luminance at the position. As shown in fig. 9, in the illumination device according to embodiment 2, the brightness of the light output surface 191a in the vicinity of the light incident surface 191c of the light guide member 19 is uniform over the entire surface in the longitudinal direction (X-axis direction). In contrast, in the lighting device of comparative example 2, the luminance on both outer sides of the light source row 17A and the luminance in the vicinity between the adjacent first LEDs 171 are lower than the luminance in the vicinity of the light exit surface 171a of the first LED 171.

< embodiment 3 >

Next, a liquid crystal display device 10B according to embodiment 3 will be described with reference to fig. 10. Fig. 10 is a sectional view of a liquid crystal display device 10B according to embodiment 3. The liquid crystal display device 10B of the present embodiment is formed with the sheet-like light reflecting member 30 interposed between the plate surface 192a on the front surface side of the extended portion 192 and the frame main body portion 161 of the frame 16 so as to overlap the second LED172 in a plan view. In embodiment 1, the frame body portion 161 of the frame 16 itself has a function of reflecting the light emitted from the second LED172 from the extension portion 192, but may be configured to include the light reflecting member 30 as a member separate from the frame 16 as in the present embodiment. The light reflection member 30 is a sheet-like member having light reflectivity, which is used for the reflection sheet 20 and the like, for example. By using such a light reflecting member 30, the light supplied from the second LED172 to the extension portion 192 of the light guide member 19 can be effectively used.

< other embodiments >

The present invention is not limited to the embodiments described above and illustrated in the drawings, and for example, the following embodiments are also included in the technical scope of the present invention.

(1) In embodiment 1 and the like, the lighting driving of the first LED171 and the second LED172 is controlled independently, but in other embodiments, the lighting driving of the first LED171 and the second LED172 may be performed in a unified manner (collectively) as long as the object of the present invention is not impaired. However, for the reason that the luminance distribution of the light emitted from the illumination device can be easily made uniform, it is preferable to perform the lighting drive of the first LED171 and the lighting drive of the second LED172 and the third LED173 independently of each other as in embodiment 1 and the like.

(2) In embodiment 1 and the like, the light emitting surface 191a is rectangular in a plan view, but the light emitting surface 191a (the area AA corresponding to the display area AA) may be other than rectangular as long as the object of the present invention is not impaired.

(3) In the above embodiments, the lighting device having a horizontally long rectangular shape in a plan view is exemplified, but the lighting device having another shape such as a vertically long rectangular lighting device in a plan view is exemplified as long as the object of the present invention is not impaired.

(4) In another implementation, the display device (liquid crystal display device) may be a television receiver provided with a tuner or the like, or may be an electronic sign (digital sign) or the like.

Description of the reference numerals

10 … display device, 12 … lighting device, 13 … bezel, 14 … case, 15 … optical sheet, 16 … frame, 170 … light source row, 171 … first light source (first LED), 171a … first light emitting part (light emitting surface), 172 … second light source (second LED), 172a … second light emitting part (light emitting surface), 173 … third light source (third LED), 173a … third light emitting part (light emitting surface), an 18 … LED substrate (light source substrate), a 19 … light guide member, a 191 … light guide main body portion, a 191a … light exit surface, a 191c … light entrance surface (first light entrance surface), a 192 … extended portion, a 192b … light entrance surface (second light entrance surface), a 20 … reflective sheet, an AA … display region, a NAA … non-display region, a light exit surface region where AA … overlaps with the display region in a plan view, and a light exit surface region where NAA … overlaps with the non-display region in a plan view.