JP5580769B2 - LED light source device and liquid crystal display device - Google Patents

Description

  The present invention relates to an LED light source device using one or a plurality of LED modules on which one or a plurality of light emitting diodes (LEDs) are mounted, and a liquid crystal display device using the LED light source device as a backlight.

  This type of conventional liquid crystal display device has a transmissive liquid crystal panel, and has a backlight behind the transmissive liquid crystal panel. Conventionally, CCFL (Cold Cathode Fluorescent Lamp) has been the mainstream as a light source device used as a backlight, but it is promising to use LED as a light source instead of CCFL due to progress in LED technology. .

  Patent Document 1 discloses that a plurality of LEDs are arranged, for example, in a row on a substrate.

  In order to further reduce the number of mounted LEDs and further reduce the thickness of the backlight, there is a backlight using a light diffusion lens that covers each of the plurality of LEDs. The light diffusing lens used for this backlight is mounted on the LED substrate with an adhesive or the like. At this time, the directions of the light diffusing lenses are all aligned in the same direction. A case where the light diffusing lens is arranged in the same direction will be described with reference to FIG.

  FIG. 6 is a plan view schematically showing an example of LED module arrangement in a conventional LED light source device.

  In FIG. 6, a conventional LED light source device 100 is composed of a plurality of LED modules 101. Here, for convenience, strip-like LED modules 101 are arranged in four rows in the horizontal direction. Among the four rows of strip-shaped LED modules 101 in the horizontal direction, the two rows of strip-shaped LED modules 101 in the center are arranged close to each other in order to improve the luminance at the center of the screen.

  Each LED module 101 includes a printed wiring board 102 and a plurality (in this case, five) of LEDs 103 mounted thereon. A light diffusing lens 104 for diffusing light from the LED 103 is attached to each LED 103 so as to cover each LED 103.

  In this case, the light diffusing lens 104 is mounted on the printed wiring board 102 so as to cover the LED 103 with an adhesive or the like. At this time, all the light diffusing lenses 104 are arranged in the same direction. The direction of the light diffusing lens 104 is fixed by contacting the three legs 104a on the printed wiring board 102, and can be specified by the direction of the three legs 104a.

  The reflection sheet 105 has a plurality of holes through which the light diffusion lens 104 penetrates together with the LED 103, and the printed wiring board 102 and the reflection sheet 105 with the LED 103 and the light diffusion lens 104 penetrating from the rear side through the LED through hole. And are fixed. Light from the plurality of LEDs 103 is reflected by the inner surface of the reflection sheet 105 and emitted forward to form a surface light source. The screen peripheral part (screen peripheral frame part) of the reflective sheet 105 is configured by four long, vertical and horizontal surfaces that are inclined so as to open forward.

JP 2003-207780 A

  Regarding the optical characteristics of the light diffusion lens 104, the light emission characteristics are not completely symmetric but biased due to the structure of the diffusion pattern on the lens foot 104a and the bottom surface of the lens. Conventionally, the light diffusing lens 104 is mounted on the substrate in the same direction because of production, so the brightness of the vertical, horizontal, and oblique streaky surface light sources is generated on the backlight. Easy to do.

  That is, when the light diffusing lenses 104 are arranged in an array, the deviation of the spread of each light is connected to the deviation of the spread of the light of the adjacent light diffusing lens 104, and as a surface light source of the backlight, Unevenness such as vertical streaks, horizontal streaks, and diagonal streaks tends to occur in the brightness. In particular, streaky lines (unevenness) generated on the screen are easily noticeable even if they are faint, causing the display quality to deteriorate.

  The present invention solves the above-described conventional problems, and can solve the streaky unevenness generated on the screen and improve the quality of the surface light source, and the LED light source device. An object of the present invention is to provide a liquid crystal display device using as a backlight.

The LED light source device of the present invention includes an LED light source device in which one or a plurality of LEDs are mounted, and a plurality of LED modules each having a lens mounted on each LED are arranged to irradiate light in a planar shape. The direction of the mounted lens is different from at least one other direction, or between the LED modules adjacent to each other, the direction of the lens is different from at least one other direction , and the lens has three legs. The position of the three legs corresponds to the apex of the isosceles triangle, and the direction of the apex angle with respect to the base of the isosceles triangle is the direction of the lens. Is achieved.

  Preferably, the LED modules in the LED light source device of the present invention have the same lens orientation or the same lens orientation.

  Furthermore, preferably, the direction of the lens on the LED module in the LED light source device of the present invention is alternately changed.

  Furthermore, preferably, the directions of the lenses on the LED module in the LED light source device of the present invention are all changed.

  Further, preferably, LED modules having different lens orientations in the LED light source device of the present invention are alternately arranged.

  Further preferably, in the LED light source device of the present invention, the angle of the lens is such that the angle formed by the first direction and the second direction is greater than 0 degree and less than 90 degrees.

  Further preferably, in the LED light source device of the present invention, the angle of the lens formed by the first direction and the second direction is an angle of 30 degrees, an angle of 45 degrees, or an angle of 60 degrees.

  Further preferably, the direction of the lens in the LED light source device of the present invention is such that the angle is 0 degrees, the angle is 30 degrees, and the angle is 0 degrees when one of the directions in which the plurality of lenses are arranged in a row is defined as an angle of 0 degrees. And an angle of 45 degrees, or a combination of the angle of 0 degrees and an angle of 60 degrees.

  Further preferably, the direction of the lens in the LED light source device of the present invention is such that when one of the directions in which the plurality of lenses are arranged in a row is an angle of 0 degrees, the angle is 0 degrees ± the angle is 15 degrees, and the angle is 0 degrees The angle is 22.5 degrees or the angle is 0 degrees ± the angle is 30 degrees.

  Further preferably, the LED module in the LED light source device of the present invention includes a printed wiring board and one or a plurality of LEDs mounted on the printed wiring board.

  Further, preferably, each of the one or more lenses for diffusing light covering each of the one or more LEDs in the LED light source device of the present invention is passed through each of the holes, and is emitted from the LED through the lens. Reflecting means for reflecting the incident light forward and illuminating it in a planar shape is provided.

  Further, preferably, the reflecting means in the LED light source device of the present invention is configured by four long and frame-shaped vertical and horizontal surfaces with inclined surfaces so that the periphery of the screen opens forward.

  Further preferably, in the LED light source device of the present invention, in the peripheral portion of the screen, a plurality of LEDs mounted on the LED module are arranged at a lower density than the central portion of the screen, and light is emitted on the inclined surface around the reflecting means. I try to take it out.

  Further preferably, in the LED light source device of the present invention, the plurality of LED modules are arranged with a high density at the center of the screen so that the luminance at the center of the screen is higher than that at the periphery of the screen, and light is irradiated in a planar shape.

  Further preferably, the LED module in the LED light source device of the present invention is an LED substrate having the same structure in which the direction of the lens covering the LED is the same, or having an LED substrate in which the direction of the lens covering the LED is different. .

  In the liquid crystal display device of the present invention, the LED light source device of the present invention is provided on the back side of the liquid crystal panel and used as a backlight, thereby achieving the above object.

  With the above configuration, the operation of the present invention will be described below.

  In the present invention, in an LED light source device in which one or a plurality of LEDs are mounted, and a plurality of LED modules each having a lens mounted on each LED are arranged to emit light in a planar shape, the lens mounted on the LED module The direction of the lens is different from at least one other direction, or between the LED modules adjacent to each other, the direction of the lens is different from at least one other direction.

  This makes it possible to use LED modules that do not have the same lens orientation, such as light diffusing lenses, to alternately use LED modules that have different lens orientations, or to change the orientation of all lenses on the LED module. The orientation of the lens mounted on this LED module is different from at least one other orientation, such as being disposed, or at least one orientation of the lens between adjacent LED modules is different from the other orientation. As a result, it becomes possible to prevent the light spread of each lens adjacent to each other from being sequentially connected in a streak pattern as in the past, and the streak-like unevenness generated on the screen is eliminated. Thus, the quality of the surface light source of the LED light source device is improved. Display quality can be improved by using the LED light source device as a backlight of a liquid crystal display device.

  As described above, according to the present invention, the LED modules in which the directions of the lenses are not aligned are arranged, or the LED modules in which the directions of the lenses are different are arranged alternately. The direction of the lens mounted on the LED module is different from the other direction, such as by changing the orientation, or the direction of the lens is different between the LED modules adjacent to each other. Is different. For this reason, since the deviation of the spread of the light of each lens adjacent to each other is not sequentially connected in a streak shape, the streaky unevenness generated on the screen can be eliminated, and the surface light source of the LED light source device The quality can be improved. Display quality can be improved by using the LED light source device as a backlight of a liquid crystal display device.

It is a top view which shows typically the example of LED module arrangement | positioning of the LED light source device in Embodiment 1 of this invention. It is a top view which shows typically the back surface structure of the light-diffusion lens which covers LED mounted on each LED module of FIG. 1, and direction of a light-diffusion lens. It is a top view which shows typically the modification of the LED module arrangement example of the LED light source device in Embodiment 1 of this invention. It is a top view which shows typically the example of LED module arrangement | positioning of the LED light source device in Embodiment 2 of this invention. It is a longitudinal cross-sectional view which shows typically the example of a principal part structure of the liquid crystal display device incorporating the LED light source device of FIG. It is a top view which shows typically the example of LED module arrangement | positioning in the conventional LED light source device.

  Hereinafter, Embodiments 1 and 2 of the LED light source device of the present invention and Embodiment 3 of a liquid crystal display device using any one of Embodiments 1 and 2 of the LED light source device as a backlight will be described in detail with reference to the drawings. Explained. In addition, each thickness, length, etc. of the structural member in each figure are not limited to the structure to illustrate from a viewpoint on drawing preparation.

(Embodiment 1)
FIG. 1 is a plan view schematically showing an LED module arrangement example of the LED light source device according to Embodiment 1 of the present invention.

  In FIG. 1, the LED light source device 1 of Embodiment 1 is composed of a plurality of LED modules 2. Here, for convenience, two strip-like LED modules 2 are arranged in four rows in the horizontal direction. . Of the four LED strips 2 in the horizontal direction, in order to improve the luminance at the center of the screen, the two LED strips 2 in the center are arranged at the center side by bringing their vertical arrangement pitches toward the center side. LEDs 4 are arranged in a dense state.

  Each LED module 2 includes a printed wiring board 3 and a plurality (in this case, five) of LEDs 4 mounted thereon. Each LED module 2 in a row is composed of a plurality (two in this case) of LED modules 2, and the two LED modules 2 are arranged between the two LED modules 2 so that the arrangement pitch of the LEDs 4 is uniform. Packed and arranged. A light diffusing lens 5 for diffusing light from the LED 4 is attached to each LED 4 so as to cover each LED 4.

  In this case, the light diffusing lens 5 is mounted on the printed wiring board 3 so as to cover the LED 4 with an adhesive or the like. At this time, the light diffusing lens 5 is arranged so that the directions thereof are alternately changed. One type of LED module 2 mounted on the printed wiring board 3 is used so that the directions of the light diffusion lenses 5 are alternately changed so that the directions of the light diffusion lenses 5 are not aligned. The three legs 5a of the light diffusing lens 5 abut on the printed wiring board 3 and are fixed with an adhesive (not shown) or the like. The direction of the light diffusing lens 5 is the direction of the three legs 5a ( The position of the three legs 5a can be specified. This will be described in more detail with reference to FIG.

  In the reflection sheet 6, a plurality of holes through which the light diffusing lens 5 mounted on the LED 4 penetrates together with the LED 4 are opened at predetermined positions. The printed wiring board 3 and the reflection sheet 6 are fixed in a state where the light diffusion lens 5 penetrates from the back side of the reflection sheet 6 together with the LEDs 4 mounted on the LED modules 2 through the plurality of through holes of the reflection sheet 6. Yes. Light from the plurality of LEDs 4 is reflected by the reflection sheet 6 through the light diffusion lens 5 and emitted forward. Thus, the LED light source device 1 is a surface light source. The screen peripheral part (screen peripheral frame part) of the reflection sheet 6 is configured by four slender surfaces 6 a long, vertical and horizontal surfaces so as to open forward.

  In this way, in order to improve the brightness of the center of the screen, the plurality of LED modules 2 in the center row are moved closer to the center and the LEDs 4 are arranged at a high density in the center, and the LEDs 4 are arranged at a low density at the periphery of the screen. Thus, light is extracted at an inclined portion around the reflection sheet 6. To the human eye, even if the central part is bright and the peripheral part is somewhat dark, it appears to be a uniform surface light source. Therefore, in order to improve the brightness of the central part of the screen, the LED board is placed in the central part of the screen. The LED distribution density is adjusted. In addition, the number of LEDs mounted can be reduced by adopting a structure in which the periphery of the screen is inclined in the shape of the reflection sheet.

  FIG. 2 is a plan view schematically showing the back surface structure of the light diffusion lens 5 covering the LEDs 4 mounted on each LED module 2 of FIG. 1 and the direction of the light diffusion lens 5.

  As shown in FIG. 2, the light diffusing lens 5 is configured to diffuse light emitted from the LED 4 and prevent the light intensity distribution from protruding forward, and is flattened forward. Due to the structure of 5a and the diffusion pattern 5b on the lens bottom surface (here, a quadrangular pyramid), the light emission characteristics are not completely left-right symmetric (left-right symmetric with respect to the direction of the light diffusion lens 5) in plan view. Has a certain bias. Conventionally, since the light diffusing lens 5 is mounted on the printed wiring board 3 in the same direction because of production, when the light from the LEDs 4 on the adjacent LED modules 2 overlaps, the LEDs 4 For example, the light diffusion lens 5 is brightened between the LED 4 adjacent to the right side, for example, and the light diffusion lens 5 is arranged in the same direction, for example, the left side. It becomes dark between the LEDs 4 adjacent to the LED 4. The way in which each light of the light diffusing lens 5 spreads is defined by the direction of the light diffusing lens 5. When the light diffusing lenses 5 are arranged in the same direction, it is connected to the bias of the light spreading of the adjacent light diffusing lenses 5, and the brightness of the backlight is very small such as vertical stripes or horizontal stripes. However, streaky unevenness is generated, which is easily noticeable by humans and causes a deterioration in display quality.

  In order to solve this, in the first embodiment, in the LED module 2, the light diffusion lens 5 is mounted on the printed circuit board 3 so that the directions of the light diffusion lens 5 are not changed by changing the direction alternately. A light diffusion lens 5 is attached to the LED 4. Since the positions of the three legs 5a of the light diffusing lens 5 correspond to the vertex positions of the isosceles triangle, the direction of the apex angle (arrows d1 and d2) with respect to the base of the isosceles triangle is defined here. The direction is defined as 5. In the LED module 2, five LEDs 4 and five light diffusion lenses 5 thereon are arranged in one row, but the directions of the light diffusion lenses 5 are alternately arranged in the directions of arrows d1 and d2. . When the direction of the arrow d1 is one of the arrangement directions of the light diffusion lenses 5 (angle 0 degree), the direction of the arrow d2 is a direction inclined by 45 degrees with respect to the direction of the arrow d1. In the first embodiment, the direction of the light diffusion lens 5 indicated by the arrow d1 and the direction of the light diffusion lens 5 indicated by the arrow d2 are alternately arranged. As a result, the spread of the light spreading of the adjacent light diffusion lenses 5 is not connected in a streak shape.

  As described above, according to the first embodiment, in the LED module 2, the direction of the light diffusing lens 5 is alternately changed, so that the light of each adjacent light diffusing lens 5 is different from the conventional one. Since the spreading biases are not successively connected in a streak shape, streaky unevenness that has conventionally occurred on the screen can be eliminated, and the quality of the surface light source can be improved.

  In the first embodiment, the direction of the light diffusing lens 5 is changed by alternately changing the direction of the plurality (here, five) of the light diffusing lenses 5 between the angle 0 degrees indicated by the arrow d1 and the angle 45 degrees indicated by d2. However, the present invention is not limited to this, and the light diffusing lens 5 is alternately changed using another angle, for example, a combination of 0 degrees and 30 degrees, or a combination of 0 degrees and 60 degrees, for example. They may be arranged so that their directions are not aligned. Further, when the arrangement direction of the light diffusing lenses 5 is set to an angle of 0 degrees, the angles at which the light diffusing lenses 5 are arranged by alternately changing the directions are, for example, an angle of 0 degrees ± 15 degrees, an angle of 0 degrees ± 22,5 degrees. Alternatively, a combination of angles of 0 ° ± 30 ° may be used, and the directions may be alternately changed so that the directions of the light diffusion lenses 5 are not aligned. In short, as the direction of the light diffusing lens 5, the angle formed by the first direction and the second direction is an angle of 30 degrees, an angle of 45 degrees, or an angle of 60 degrees. Furthermore, if the direction of the light diffusing lens 5 is such that the angle between the first direction and the second direction is greater than 0 degrees and less than 90 degrees, each adjacent light diffusing lens 5 is conventional as in the prior art. It is possible to prevent the deviation of the spread of light from being sequentially connected in a streak shape.

  Since the diffusion pattern 5b on the bottom surface of the light diffusing lens 5 has a large number of quadrangular pyramid structures protruding downward, the quadrangular pyramid structures have the same shape with a period of 90 degrees and 180 degrees. The angle difference between the directions of the light diffusing lenses 5 that are arranged in a different manner may be any angle other than 90 degrees and 180 degrees. Therefore, it is only necessary that the light diffusion lens 5 is mounted on the LED module 2 so that the directions of the light diffusion lenses 5 are not aligned. That is, the direction of at least one of the plurality of (here, five) light diffusion lenses 5 on the LED module 2 may be different from the direction of the other light diffusion lenses 5. Of course, among the plurality of (here, five) light diffusion lenses 5 on the LED module 2, all the light diffusion lenses 5 may have different directions. The case where the directions of all the light diffusion lenses 5 are different will be further described in detail with reference to FIG.

  FIG. 3 is a plan view schematically showing a modification of the LED module arrangement example of the LED light source device 1 according to Embodiment 1 of the present invention.

  As shown in FIG. 3, in the LED module 2A used in a plurality of LED light source devices 1A, the directions of all the light diffusion lenses 5 are different. The direction d1 of the leftmost light diffusion lens 5 coincides with one of the arrangement directions of the five light diffusion lenses 5 arranged in a line on the printed wiring board 3 of the LED module 2A. The direction d3 of the second light diffusing lens 5 from the left has an inclination of an angle 30 with respect to the direction d1 (angle 0 degree) in the arrangement direction of the five light diffusing lenses 5. The direction d4 of the third light diffusing lens 5 from the left has an inclination of an angle 60 with respect to the direction d1 (angle 0 degree) in the arrangement direction of the five light diffusing lenses 5. The direction d5 of the fourth light diffusing lens 5 from the left has an inclination of an angle 90 with respect to the direction d1 (angle 0 degree) in the arrangement direction of the five light diffusing lenses 5. Further, the direction d6 of the fifth light diffusing lens 5 from the last left has an inclination of an angle 120 with respect to the direction d1 (angle 0 degree) in the arrangement direction of the five light diffusing lenses 5. As described above, the five light diffusion lenses 5 are sequentially added at an angle of 30 degrees when attached to the LED 4 to change the direction of the light diffusion lens 5.

  Thus, since all the light diffusion lenses 5 mounted on the LED module 2A are arranged in different directions, the light spreading of the light diffusion lenses 5 adjacent to each other is different from that of the conventional one. Since they are not connected in a streak shape, it is possible to eliminate the unevenness of the streak-like brightness that has conventionally occurred on the screen, and to improve the quality of the surface light source.

  In short, it is important that the directions of the plurality of light diffusion lenses 5 are not aligned. In the first embodiment, the direction of the plurality of light diffusing lenses 5 is alternately arranged on the LED module 2 in order to prevent the light spreading biases of the adjacent light diffusing lenses 5 from being connected in a streak shape. The direction is changed, or all the directions of the plurality of light diffusion lenses 5 are changed on the LED module 2A. Furthermore, the direction of at least one of the plurality of (here, five) light diffusion lenses 5 on the LED module 2 may be different from the direction of the other light diffusion lenses 5. .

(Embodiment 2)
In the first embodiment, the case where the LED modules 2 or 2A in which the directions of the light diffusing lenses are not aligned has been described, but in the second embodiment, the case where the substrates having different directions of the light diffusing lenses are alternately arranged is described. To do.

  FIG. 4 is a plan view schematically showing an LED module arrangement example of the LED light source device according to Embodiment 2 of the present invention.

  In FIG. 4, the LED light source device 1B according to the second embodiment is composed of two types of LED modules 2B1 and 2B2. Here, for convenience, two strip-like LED modules 2B1 and 2B2 are arranged in four rows in the horizontal direction. It is arranged in one row. Of the four LED strips 2B1 and 2B2 in the horizontal direction, in order to improve the brightness at the center of the screen, the LED array 2B1 and 2B2 in the center two rows have their vertical arrangement pitches set toward the center. The LEDs 4 on the center side are arranged so as to be in a dense state.

  The LED modules 2B1 and 2B2 are alternately arranged. For example, the LED module 2B1, the LED module 2B2, the LED module 2B1, and the LED module 2B2 are arranged in this order on the left side of the reflection sheet 6B from the top to the bottom in the plan view. Modules 2B1 and 2B2 are arranged alternately. Similarly, on the right side of the reflection sheet 6B in the plan view, the LED module 2B2, the LED module 2B1, the LED module 2B2, and the LED module 2B1 are arranged in this order from the top to the bottom in the plan view. Different LED modules 2B1 and 2B2 are alternately arranged. Moreover, the first row is arranged in the order of the LED module 2B1 and the LED module 2B2, and the second row is arranged in the order of the LED module 2B2 and the LED module 2B1 in the reverse order of the first row. Furthermore, the third row is the reverse of the second row and is arranged in the order of the LED module 2B1 and the LED module 2B2, and the fourth row is the reverse of the third row and is arranged in the order of the LED module 2B2 and the LED module 2B1. Yes.

  Each of the LED modules 2B1 and 2B2 has a printed wiring board 3 and a plurality (in this case, five) of LEDs 4 mounted thereon. Each of the LED modules 2B1 and 2B2 in a row is composed of a plurality (two in this case) of LED modules, and the two LED modules 2B1 and 2B2 have two LED modules so that the arrangement pitch of the LEDs 4 is equal. 2B1 and 2B2 are arranged close together. A light diffusing lens 5 for diffusing light from the LED 4 is attached to each LED 4 so as to cover each LED 4.

  In this case, the light diffusion lens 5 is mounted on the printed wiring board 3 so as to cover the LED 4 with an adhesive or the like. At this time, the light diffusion lens 5 is oriented in the same direction in each of the LED modules 2B1 and 2B2. Is arranged. Two types of LED modules 2B1 and 2B2 having “directions” mounted on the printed wiring board 3 so that the direction of the light diffusion lens 5 is changed for each LED module 2B and the direction of the light diffusion lens 5 is not aligned are used. . The three legs 5a of the light diffusing lens 5 abut on the printed circuit board 3 and are fixed with an adhesive (not shown). The direction of the light diffusing lens 5 depends on the direction of the three legs 5a. Can be identified.

  That is, in the LED modules 2B1 and 2B2, the five LEDs 4 and the five light diffusion lenses 5 are arranged in one row, but in the LED module 2B1, the directions of all the five light diffusion lenses 5 are the arrows d1. In the LED module 2B2, the directions of all five light diffusion lenses 5 are arranged in the direction of the arrow d2. When the direction of the arrow d1 is one of the arrangement directions of the light diffusion lenses 5 (angle 0 degree), the direction of the arrow d2 is a direction inclined by 45 degrees with respect to the direction of the arrow d1. In the second embodiment, the LED module 2B1 in the direction of the light diffusion lens 5 indicated by the arrow d1 and the LED module 2B2 in the direction of the light diffusion lens 5 indicated by the arrow d2 are alternately arranged vertically and horizontally. As a result, the spread of the light spreading of the adjacent light diffusion lenses 5 is not connected in a streak shape.

  In the reflection sheet 6B, a plurality of holes through which the light diffusing lens 5 mounted on the LED 4 penetrates together with the LED 4 are opened at predetermined positions. The printed wiring board 3 and the reflection sheet 6B are fixed with the light diffusion lens 5 penetrating from the back side of the reflection sheet 5 together with the LEDs 4 mounted on the LED modules 2B1 and 2B2 through the plurality of through holes of the reflection sheet 6B. Has been. Light from the plurality of LEDs 4 passes through the light diffusing lens 5 and is reflected by the reflection sheet 6B and emitted forward. Thus, the LED light source device 1B is a surface light source. As for the screen peripheral part (screen peripheral frame part) of the reflection sheet 6B, the long, vertical and horizontal four surfaces are each comprised by the inclined surface 6a so that it may open ahead.

  Thus, in order to improve the brightness of the center of the screen, the plurality of LED modules 2B1 and 2B2 in the center row are moved toward the center and the LEDs 4 are arranged at a high density in the center, and the LEDs 4 are low-density at the periphery of the screen. The light is extracted at the inclined portion around the reflection sheet 5. To the human eye, even if the central part is bright and the peripheral part is somewhat dark, it appears to be a uniform surface light source. Therefore, in order to improve the brightness of the central part of the screen, the LED board is placed in the central part of the screen. The LED distribution density is adjusted. Further, the number of LEDs mounted can be reduced by adopting a structure in which the periphery of the screen is inclined to the shape of the reflection sheet 6B.

  As described above, according to the second embodiment, since the two types of LED modules 2B1 and 2B2 having different directions of the light diffusion lens 5 are alternately arranged in the top and bottom and left and right in a plan view, Since the deviation of the light spreading direction of the light diffusing lens 5 is not sequentially connected in a streak shape, it is possible to eliminate the streaky unevenness that has conventionally occurred on the screen and to improve the quality of the surface light source. it can.

  In the second embodiment, the LED modules 2B1 in which the directions of all the five light diffusion lenses 5 are arranged in the direction of the arrow d1 (the arrangement direction of the light diffusion lenses 5 having an angle of 0 degrees) and all the five light diffusion lenses 5 are arranged. The LED modules 2B2 in which the direction of the light diffusing lens 5 is arranged in the direction of the arrow d2 (angle 45 degrees with respect to the arrow d1) are alternately arranged on the left and right and top and bottom. The orientation of the light diffusing lens 5 is changed between the LED modules 1B1 and 2B2 by alternately changing the arrangement of the LED modules 2B1 and 2B2 using, for example, a combination of 0 degrees and 30 degrees, or a combination of 0 degrees and 60 degrees, for example. You may arrange so that it may not align. Further, as the lens arrangement angle for each LED module in which the light diffusing lens 5 is alternately changed in direction, for example, a combination of ± 22, 5 degrees or ± 30 degrees is used, and the light diffusing lens 5 is alternately changed in direction. They may be arranged so that their directions are not aligned. In short, since the diffusion pattern 5b on the bottom surface of the light diffusion lens 5 has a protruding quadrangular pyramid structure, it has the same shape with a period of 90 degrees and 180 degrees, so that the LED modules are alternately arranged in different directions. The angle difference between the directions of the light diffusing lens 5 may be any angle other than 90 degrees and 180 degrees. Therefore, the LED modules 2B1 and 2B2 having different light diffusion lens orientations are alternately arranged. It is only necessary that the light diffusion lens 5 is mounted so that the direction of the light diffusion lens 5 is not aligned for each LED module.

  In Embodiments 1 and 2, although not specifically described in detail, one or a plurality of LEDs are mounted, and a plurality of LED modules each having a lens mounted thereon are disposed, and light is emitted in a planar shape. In the illuminating LED light source device, the direction of the lens mounted on the LED module is different from at least one other direction, or the direction of the lens is different from at least one other direction between adjacent LED modules. As a result, the streaky unevenness generated on the screen can be eliminated, and the object of the present invention which can improve the quality of the surface light source can be achieved. In this case, there may be a combination of diffusing lenses in the same direction at one place on the screen. The unevenness does not necessarily occur on the entire screen, and unevenness occurs only in a part of the screen, but if the direction of the lens is different from at least one other LED module between adjacent LED modules, Therefore, it is possible to eliminate unevenness that should occur if the lens orientations are aligned.

(Embodiment 3)
In the liquid crystal display device according to the third embodiment, any one of the LED light source devices 1, 1A, and 1B in FIGS. 1, 3, and 4 can be incorporated into the liquid crystal display device as a backlight. Here, in FIG. The case where the LED light source device 1 is incorporated in a liquid crystal display device as a backlight will be described with reference to FIG.

  FIG. 5 is a longitudinal sectional view schematically showing an example of the configuration of the main part of a liquid crystal display device incorporating the LED light source device 1 of FIG.

  In FIG. 5, in the liquid crystal display device 20 according to the third embodiment, a plurality of LEDs 4 are arranged on the printed wiring board 3, and the above-described light diffusion lenses 5 alternate their directions so as to cover the respective LEDs 4. The LED light source device 1 according to the first embodiment, which is an LED backlight in which a plurality of LED modules 2 provided in a modified manner are arranged and surface-emitting, and the LED light source device 1 above the reflective light source 6 by a distance L. An optical sheet 21 including a provided light diffusion sheet and the like, and a light transmissive liquid crystal panel 22 capable of displaying a liquid crystal image based on a display signal, and the LED light source device 1 is a rear surface of the light transmissive liquid crystal panel 22. It is provided on the side and used as a backlight.

  The LED light source device 1 has a plurality of LED modules 2 in the center row arranged close to each other to increase the brightness at the center of the screen and arranges the LEDs 4 at a high density in the center, and the LEDs 4 are arranged at a low density at the periphery of the screen. The light is extracted from the inclined portion (inclined surface 6 a) around the reflection sheet 5. In addition, in each LED module 2, the orientations of the two types of light diffusing lenses 5 are alternately changed, so that the light spreading of each adjacent light diffusing lens 5 is biased as in the conventional case. Are not sequentially connected in a streak shape.

  As described above, according to the third embodiment, the LED light source device 1 irradiates a plurality of LED modules 2 with a high density at the center of the screen so that the luminance at the center of the screen is high, and emits light in a planar shape. In the LED module 2, the LED light source device 1 in which the orientations of the two types of light diffusion lenses 5 are alternately changed is provided on the back side of the liquid crystal panel 22 and used as a backlight.

  As a result, the liquid crystal display device 20 according to the third embodiment can eliminate streak-like unevenness generated on the screen, and improve the display quality by improving the quality of the surface light source.

  As mentioned above, although this invention has been illustrated using preferable Embodiment 1-3 of this invention, this invention should not be limited and limited to this Embodiment 1-3. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments 1 to 3 of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  The present invention relates to an LED light source device in which one or a plurality of LED modules on which one or a plurality of light emitting diodes (LEDs) are mounted and a liquid crystal display device in which the LED light source device is used as a backlight. Arrange LED modules that do not have the same orientation, or alternately arrange LED modules with different lens orientations, or arrange all the orientations of the lenses on the LED modules, etc. The direction of the lens mounted on the LED module is different from at least one other direction, or between the adjacent LED modules, the direction of the lens is different from at least one other direction. For this reason, since the deviation of the spread of the light of each lens adjacent to each other is not sequentially connected in a streak shape, the streaky unevenness generated on the screen can be eliminated, and the surface light source of the LED light source device The quality can be improved. Display quality can be improved by using the LED light source device as a backlight of a liquid crystal display device.

1, 1A, 1B LED light source device 2, 2A, 2B1, 2B2 LED module 3 Printed wiring board 4 LED (light emitting diode)
5 Light Diffusing Lens 5a Three Legs 5b 4 Pyramid Diffusion Pattern 6, 6B Reflective Sheet 6a Inclined Surface d1 to d6 Arrows (Direction of Light Diffusing Lens)
20 Liquid crystal display device 21 Optical sheet 22 Light transmission type liquid crystal panel

Claims (16)

In an LED light source device in which one or a plurality of LEDs are mounted, and a plurality of LED modules each having a lens mounted thereon are arranged to emit light in a planar shape,
The direction of the lens mounted on the LED module is different from at least one other direction, or the direction of the lens is different from at least one other direction between the LED modules adjacent to each other ,
The lens is provided with three legs, the positions of the three legs correspond to the vertices of the isosceles triangle, and the LED having the apex angle direction with respect to the base of the isosceles triangle as the direction of the lens Light source device.   The LED light source device according to claim 1, wherein the LED module has the same lens orientation or the lens orientation is not uniform.   The LED light source device according to claim 1, wherein directions of the lenses on the LED module are alternately changed.   The LED light source device according to claim 1, wherein all the directions of the lenses on the LED module are arranged in different directions.   The LED light source device according to claim 1, wherein LED modules having different lens orientations are alternately arranged.   6. The LED light source device according to claim 1, wherein an angle between the first direction and the second direction is greater than 0 degrees and less than 90 degrees.   The LED light source device according to claim 6, wherein an angle formed by the first direction and the second direction is an angle of 30 degrees, an angle of 45 degrees, or an angle of 60 degrees.   The direction of the lens is such that when one of the directions in which the plurality of lenses are arranged in a row is 0 degree, the angle is 0 degree and 30 degrees, the angle is 0 degrees and 45 degrees, or the angle is 0 degrees. The LED light source device according to claim 7, wherein the LED light source device has a combination of an angle of 60 degrees.   The direction of the lens is such that the angle 0 degree ± angle 15 degree, the angle 0 degree ± angle 22.5 degrees, or the angle 0 degree when one of the directions in which the plurality of lenses are arranged in a row is defined as 0 degree. The LED light source device according to claim 7, wherein the angle is ± 30 degrees.   The LED light source device according to claim 1, wherein the LED module includes a printed wiring board and one or a plurality of LEDs mounted on the printed wiring board. Each of the one or more lenses for diffusing light covering each of the one or more LEDs is passed through each hole, and the emitted light from the LED through the lens is reflected forward to light in a planar shape. The LED light source device according to claim 10 , further comprising a reflecting means for illuminating. The LED light source device according to claim 11 , wherein the reflecting means is formed of four long and frame-shaped vertical and horizontal surfaces with inclined surfaces so that a peripheral portion of the screen opens forward. 13. The light emitting device according to claim 12 , wherein a plurality of LEDs mounted on the LED module are arranged at a lower density in the peripheral portion of the screen than in the central portion of the screen so that light is extracted from an inclined surface around the reflecting means. LED light source device.   2. The LED light source device according to claim 1, wherein the plurality of LED modules are arranged with a high density at the center of the screen so that the luminance at the center of the screen is higher than that at the periphery of the screen, and light is irradiated in a planar shape.   2. The LED light source device according to claim 1, wherein the LED module is an LED substrate having the same structure in which the direction of the lens covering the LED is the same, or having an LED substrate in which the direction of the lens covering the LED is different. The liquid crystal display device LED light source device according to any one of claims 1 to 15 is used as a backlight provided on the back side of the liquid crystal panel.