JP2009140867A - Illuminating device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating device which can mix a plurality of color lights with efficiency and can be made thinner. <P>SOLUTION: The illuminating device has: a light source group 11 containing a plurality of light sources 11R, 11G, 11B which emit respective different color lights; and a reflector 15. The reflector 15 has a diffuse reflector 15A the surface of which has a predetermined angle of inclination to be inclined and located. Respective color lights LR, LG, LB emitted from the light source group 11 are incident from the side surface directions to the same region of the diffuse reflector 15A. The incident respective color lights are mixed and reflected as an illumination light (white light 17) toward an illuminated object. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an illuminating device that mixes a plurality of color lights and uses it as illumination light, and a display device using the illuminating device.

  2. Description of the Related Art Conventionally, for example, a light source using a rod-like fluorescent tube such as a CCFL (Cold Cathode Fluorescent Lamp) is known as a light source for a backlight of a liquid crystal display device. There has also been proposed a backlight that uses a rod-shaped ultraviolet lamp as a light source and converts ultraviolet light into visible light to produce illumination light (see Patent Document 1).

JP 2001-266605 A

  More recently, LEDs using light emitting diodes (LEDs) have begun to appear as backlight light sources. As the backlight, there are a backlight that mixes colors of LEDs of R (red), G (blue), and B (blue), and a backlight that emits white light with a single LED chip. In particular, when LED of each color is used, a wide color display range can be obtained. Therefore, a backlight using the color light as a backlight has been put into practical use. In this case, as a configuration of the backlight, in general, a light guide type that guides light from a light source arranged in a lateral direction with respect to the illumination target to the illumination target side through the light guide plate, and a light source directly below the illumination target There is a direct type with the. In addition, a diffusion plate is disposed on the light emission side of the backlight to make the illumination light uniform.

  Here, in the case of the light guide type, since each color light of R, G, B can be mixed while transmitting a relatively long distance by total reflection inside the light guide plate, the color mixing performance is high. Further, devising the design of the light guide plate is advantageous for reducing the thickness. However, in the case of the light guide type, there is a problem in the method of extracting the light to be emitted, and generally, the function that the light entering the light guide plate due to total reflection is contradictory to the outside of the plate and the inside of the plate are contradictory. For this reason, there is a disadvantage in that it contradicts in that respect and the light use efficiency is poor. In addition, since the weight increases, it is not often used in large-sized devices. On the other hand, the direct type has good light utilization efficiency, but a light source must be disposed relatively close to the back surface of the diffusion plate, so that the optical paths necessary for sufficiently mixing the R, G, and B color lights are necessary. Since the length corresponds to the thickness direction of the direct optical box, there is a drawback that it is difficult to reduce the thickness.

  As described above, both the light guide type and the direct type have advantages and disadvantages. In particular, the direct type used in a large-sized liquid crystal television or the like efficiently performs color mixing and reduces chromaticity unevenness. This is an issue.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an illumination device and a display device that can efficiently mix a plurality of color lights and can be thinned.

  The illuminating device of the present invention includes a light source group including a plurality of light sources each emitting different colored light and a diffuse reflection surface whose surface is inclined with a predetermined angle. Each emitted color light is incident from the side surface direction, and includes a reflecting plate that mixes each incident color light and reflects it to the illumination target side as illumination light.

  The display device of the present invention is a display device that includes a lighting device and a display unit that displays an image using illumination light from the lighting device as display light. It is comprised by the illuminating device.

  In the illuminating device or the display device of the present invention, each color light emitted from the light source group is incident from the side surface direction on the same part of the diffuse reflection surface whose surface is inclined with a predetermined angle. The incident color lights are mixed and reflected as illumination light on the illumination target side.

In the illuminating device of the present invention, a plurality of reflectors and light source groups are provided, and the reflectors and the light source groups are alternately arranged in parallel in the same in-plane direction. A light source group may be arranged on the screen. Then, each color light may be incident from the side surface direction on each of the diffuse reflection surfaces of the plurality of reflecting plates, and each incident color light may be mixed and reflected as illumination light.
In this case, since a plurality of reflectors and light source groups are alternately arranged in parallel in the same in-plane direction, it is easy to reduce the thickness as a whole.

  According to the illuminating device or the display device of the present invention, each color light emitted from the light source group is incident on the same part of the diffuse reflection surface whose surface is inclined with a predetermined angle from the side surface direction, and each incident color Since the light is mixed and reflected as illumination light on the illumination target side, a plurality of color lights can be mixed efficiently and the thickness can be reduced.

  In particular, when a configuration in which a plurality of reflectors and light source groups are alternately arranged in parallel in the same in-plane direction, it becomes easier to reduce the thickness.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]

FIG. 1 shows the basic principle of the lighting device according to the first embodiment of the present invention.
This illuminating device includes a first light source group 11 disposed on the left side, and a first reflecting plate 15 whose surface is a diffuse reflection surface 15A to which light from the first light source group 11 is irradiated. I have. The first reflecting plate 15 is inclined so that the diffuse reflecting surface 15A has a predetermined angle θ. The illumination device also includes a second light source group 13 disposed on the right side, and a second reflecting plate 16 having a diffuse reflection surface 16A on which the surface is irradiated with light from the second light source group 13. It has. The diffuse reflection surface 16A of the second reflection plate 16 is inclined so as to have a predetermined angle θ in the opposite direction to the diffusion reflection surface 15A of the first reflection plate 15. The second light source group 13 and the second reflecting plate 16 are arranged substantially symmetrically with respect to the first light source group 11 and the first reflecting plate 15. A diffusion plate 10 is disposed on the upper side (light emission side) of the illumination device.

  The first light source group 11 includes a red light source 11R that emits red light LR, a green light source 11G that emits green light LG, and a blue light source 11B that emits blue light LB. Each light source 11R, 11G, and 11B is provided with condensing mirrors 12R, 12G, and 12B, respectively. The respective color lights LR, LG, LB from the respective light sources 11R, 11G, 11B are irradiated to the same part of the diffuse reflection surface 15A of the first reflecting plate 15 from the side surface direction by the condenser mirrors 12R, 12G, 12B. It has become. The diffuse reflection surface 15A mixes the incident color lights LR, LG, and LB to form white light 17, which is reflected as illumination light on the illumination target side.

  Similarly, the second light source group 13 includes a red light source 13R that emits red light LR, a green light source 13G that emits green light LG, and a blue light source 13B that emits blue light LB. The light sources 13R, 13G, and 13B are provided with condenser mirrors 14R, 14G, and 14B, respectively. The respective color lights LR, LG, LB from the light sources 13R, 13G, 13B are irradiated to the same part of the diffuse reflection surface 16A of the second reflection plate 16 from the side surface direction by the condenser mirrors 14R, 14G, 14B. It has become. The diffuse reflection surface 16A is additively mixed with the incident color lights LR, LG, and LB to form white light 17, which is reflected as illumination light on the illumination target side (upper side).

  In this illuminating device, the respective color lights LR, LG, LB from the first light source group 11 are arranged not on the second reflector 16 arranged near the first light source group 11 but on the opposite side. Further, the light is applied to the diffuse reflection surface 15A of the first reflection plate 15. On the diffuse reflection surface 15A, the color lights LR, LG, and LB are overlapped and combined. In this case, since the light from the point light sources 11R, 11G, and 11B is developed to the area of the small slope by the diffuse reflection surface 15A, unevenness can be extremely reduced. The same applies to the second light source group 13 arranged on the opposite side. In this lighting device, a sufficient distance can be obtained between the light source and the irradiation surface, and light can be efficiently mixed by irradiating light uniformly and over a wide range, but such a configuration can be realized if sufficient thickness can be taken. It is. Moreover, in this illuminating device, by using very large output LEDs as light sources, only one LED of each color of R, G, and B is used as the first light source group 11 and the second light source group 13. A simple configuration can be obtained.

FIG. 2 shows a configuration example in which the configuration shown in the basic principle of FIG. 1 is made thinner.
The lighting device shown in FIG. 2 has a plurality of LED groups 21 as a light source group and a plurality of reflecting plates 23, and the LED groups 21 and the reflecting plates 23 are alternately arranged in parallel in the same in-plane direction. is there. The surface of the reflection plate 23 is a diffuse reflection surface 23A to which light from the LED group 21 is irradiated. The diffuse reflection surface 23A is inclined so as to have a predetermined angle θ. In this lighting device, for example, one LED group 21 is located at one end in the horizontal direction of the casing 18 (left end in the example of FIG. 2), and the other end in the horizontal direction (right end in the example of FIG. 2). The LED groups 21 and the reflection plates 23 are alternately arranged so that one reflection plate 23 is located in the section).

  In this illuminating device, the LED group 21 is arranged in the side surface direction with respect to each of the plurality of reflecting plates 23, and each color light LR, LG, LB is transmitted from the side surface direction on each of the diffuse reflection surfaces 23 </ b> A of the plurality of reflecting plates 23. The incident color lights LR, LG, and LB are mixed and reflected as illumination light.

  In this illuminating device, the LED group 21 includes at least one set of a red LED 21R that emits red light LR, a green LED 21G that emits green light LG, and a blue LED 21B that emits blue light LB. In the configuration example shown in FIG. 2, the LED group 21 has two sets of red LEDs 21R, green LEDs 21G, and blue light 21B, which are arranged at a predetermined pitch in the vertical direction (vertical direction). In addition, LEDs for each color are alternately arranged so that adjacent ones have different colors.

  In this illuminating device, a condensing lens sheet 22 as a condensing unit is disposed between the LED group 21 and the reflecting plate 23. As shown in an enlarged view in FIG. 3, the condensing lens sheet 22 has a plurality of prism-like lenses formed on its surface and has a refractive power in the vertical direction, and each color light LR, LG, The LB is condensed on the same part of the diffuse reflection surface 23A of the reflection plate 23.

  In this lighting device, the distance L1 (FIG. 2) between the adjacent LED groups 21 and the overall thickness D1 can be arbitrarily configured. Moreover, the inclination angle θ of the reflecting plate 23 can be appropriately set according to the physical dimensions of the LED group 21. The inclination angle θ is preferably 45 ° or less. In order to reduce the number of LEDs used in the LED group 21, the angle θ should be reduced.

  In this illuminating device, each color light LR, LG, LB from the LED group 21 is additively mixed by the diffusive reflecting surface 23A of the reflecting plate 23 to obtain white light 24, which is reflected to the illumination target side (upper side) as illumination light. In this respect, the principle of generating the illumination light is the same as that of the configuration example of FIG.

FIG. 4 shows an example of a display device using the lighting device according to this embodiment.
This display device is a transmissive liquid crystal display device, and includes a backlight 1, a liquid crystal panel 2, and a diffusion plate 10 disposed between the backlight 1 and the liquid crystal panel 2. The backlight 1 is configured using the lighting device (FIG. 1 or 2) according to the present embodiment. The liquid crystal panel 2 is a display unit that displays an image using illumination light from the backlight 1 as display light.

  In this display device, illumination light from the backlight 1 is irradiated from the back side of the liquid crystal panel 2 through the diffusion plate 10. The liquid crystal panel 2 displays an image by modulating the illumination light based on the image signal.

As described above, according to the illumination device of the present embodiment, as shown in FIG. 1, the light source group 11 is disposed on the same part of the diffuse reflection surfaces 15A and 16A whose surfaces are inclined with a predetermined angle. , 13 is incident from the side surface direction, and the incident color lights LR, LG, LB are mixed and reflected to the illumination target side as illumination light. The color lights LR, LG, and LB can be mixed efficiently, and the thickness can be reduced. In particular, as shown in FIG. 2, when the reflector 23 and the LED group 21 as the light source group are alternately arranged in parallel in the same in-plane direction, it becomes easier to reduce the thickness.
[Second Embodiment]

  Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as the said 1st Embodiment, and description is abbreviate | omitted suitably.

  FIGS. 5A and 5B and FIGS. 6A and 6B show a configuration example of a lighting apparatus according to the second embodiment of the present invention. In particular, in FIGS. 5A and 6B, the lighting device is viewed from the side, in FIG. 5B is viewed obliquely from the top surface direction, and in FIG. 6A is viewed from above. It is shown.

  This illumination device includes a plurality of LED groups 31 as a light source group and a plurality of reflecting plates 23. The LED group 31 and the reflection plate 23 are alternately arranged in parallel in the same in-plane direction as in the configuration example of FIG. However, the arrangement of the LEDs in the LED group 31 is different from the configuration example of FIG.

In this lighting device, the LED group 31 includes at least one set of a red LED 31R that emits red light LR, a green LED 31G that emits green light LG, and a blue LED 31B that emits blue light LB. Each of the LEDs 31R, 31G, and 31B is configured by a side emission type LED whose side surface direction is the light emitting surface 30. Each LED 31R, 31G, 31B also has a driving electrode 31A.
Here, in the present embodiment, for example, the red LED 31R corresponds to a specific example of the “first light source” in the present invention, and the green LED 31G corresponds to a specific example of the “second light source” in the present invention. For example, the blue LED 31B corresponds to a specific example of “third light source” in the present invention.

  In this lighting device, for example, one LED group 31 is located at one end of the housing 18 in the horizontal direction (left end in the example of FIG. 5A), and the other end in the horizontal direction (FIG. 5 ( In the example of A), the LED groups 31 and the reflection plates 23 are alternately arranged so that one reflection plate 23 is positioned at the right end portion).

  In the LED group 31, each LED 31R, 31G, 31B is linearly arranged in the first direction (vertical direction (y direction in the figure)) as shown in FIG. 5 (B) and FIG. 6 (A). Has been. A plurality of LED groups 31 are arranged in a second direction (horizontal horizontal direction (x direction in the figure)) orthogonal to the first direction. And the order of arrangement | positioning of each LED31R, 31G, 31B differs between adjacent LED groups 31, and it is set as the arrangement | positioning which each LED31R, 31G, 31B appears alternately in a 2nd direction. That is, taking FIG. 5B as an example, in the leftmost LED group 31, a blue LED 31B, a red LED 31R, and a green LED 31G are arranged in this order from the front side. In the right LED group 31, a green LED 31G, a blue LED 31B, and a red LED 31R are arranged in this order from the front side. As a result, when the plurality of LED groups 31 are viewed as a whole, the arrangement is such that LEDs of different colors in the vertical and horizontal directions are alternately arranged two-dimensionally. Thereby, it is set as arrangement | positioning with high space utilization efficiency of LED as a light source.

  In this illuminating device, a condensing lens sheet 32 as a condensing means is disposed between the LED group 21 and the reflecting plate 23. As shown in FIG. 6 (A), the condensing lens sheet 32 has a plurality of prism-like lenses formed on its surface and has a refractive power in the horizontal direction, and each color light LR, LG, The LB is condensed on the same part of the diffuse reflection surface 23A of the reflection plate 23.

In this illuminating device, each color light LR, LG, LB from the LED group 31 is additively mixed by the diffusive reflecting surface 23A of the reflecting plate 23 to obtain white light 24, which is reflected as illumination light on the illumination target side (upper side). In this respect, the principle of generating illumination light is the same as that of the configuration example of FIG. The basic operation and effect are the same as those of the configuration example of FIG.
[Third Embodiment]

  Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as each above-mentioned embodiment, and description is abbreviate | omitted suitably.

FIG. 7 shows a configuration example of a lighting apparatus according to the third embodiment of the present invention.
In the second embodiment, the LEDs 31R, 31G, and 31B are linearly arranged in the first direction in the LED group 31, and the light beams LR, LG, and LB from the LED group 31 are collected into the condensing lens sheet 32. Therefore, the light is condensed on the same part of the diffuse reflection surface 23A. On the other hand, in the present embodiment, at least one of the LEDs 31R, 31G, and 31B in the LED group 31 is arranged to be inclined in the horizontal plane, whereby each color light LR, LG, and LB is the same on the diffuse reflection surface 23A. It concentrates on the part.

  In this illuminating device, a condensing lens sheet 33 as a condensing unit may be disposed between the LED group 21 and the reflecting plate 23. However, the condensing lens sheet 33 may be omitted from the configuration if the LEDs 31R, 31G, and 31B in the LED group 31 can be sufficiently condensed on the same part of the diffuse reflection surface 23A by devising the arrangement. The condensing lens sheet 33 has refractive power in the horizontal direction, and diffusely reflects each color light LR, LG, LB from the LED group 31 that cannot be sufficiently collected only by the arrangement of the LEDs 31R, 31G, 31B. It concentrates on the same site | part of the surface 23A.

In this illuminating device, each color light LR, LG, LB from the LED group 31 is additively mixed by the diffusive reflecting surface 23A of the reflecting plate 23 to form white light 24, which is reflected as illumination light on the illumination target side (upper side). In this respect, the principle of generating illumination light is the same as that of the configuration example of FIG. The basic operation and effect are the same as those of the configuration example of FIG.
[Fourth Embodiment]

  Next, a fourth embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as each above-mentioned embodiment, and description is abbreviate | omitted suitably.

  FIGS. 8A and 8B show a configuration example of a lighting device according to the fourth embodiment of the present invention. In particular, FIG. 8A illustrates a state in which the lighting device is viewed from above, and FIG. 8B illustrates a state in which the lighting device is viewed from side.

  This illumination device includes a plurality of LED groups 51 as a light source group and a plurality of reflecting plates 23. The LED group 51 and the reflection plate 23 are alternately arranged in parallel in the same in-plane direction, for example, as in the configuration example of FIGS. However, although the side emission LED is used as the light source in the configuration examples in FIGS. 6A and 6B, a top emission LED is used in this embodiment.

  In this illuminating device, the LED group 51 includes at least one set of a red LED 51R that emits red light LR, a green LED 51G that emits green light LG, and a blue LED 51B that emits blue light LB. Each of the LEDs 51R, 51G, 51B is composed of a top emission type LED whose top surface direction is the light emitting surface 30. Each LED 51R, 51G, 51B also has an electrode 31A for driving.

In this lighting device, the back surface of the reflection plate 23 (the back surface side of the diffuse reflection surface 23A) is the reflection surface 23B. Then, the LED group 51 is arranged on the back surface side of the reflecting plate 23, and the respective color lights LR, LG, and LB emitted from the LED group 51 are reflected by the reflecting surface 23B on the back surface side of the reflecting plate 23 and then adjacent to each other. It is configured to enter the diffuse reflection surface 23 </ b> A of the other reflector 23. The reflecting surface 23B is configured by performing specular reflection coating on the surface.

This illuminating device uses a top emission type LED as a light source, and irradiates each of the color light beams LR, LG, LB from the LED group 51 to the diffuse reflection surface 23A of the reflection plate 23 via the reflection surface 23B on the back surface of the reflection plate 23. Except for this point, the other basic functions and effects are the same as those of the configuration example of the second embodiment.
[Fifth Embodiment]

  Next, a fifth embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as each above-mentioned embodiment, and description is abbreviate | omitted suitably.

  For example, in the illuminating device shown in the second embodiment, there is a possibility that a difference in luminance occurs depending on the observation direction and a bright line is generated. That is, as shown in FIG. 9, the reflected light reflected by the diffuse reflection surface 23A of the reflector 23 is dominantly observed in the first direction M, and is reflected by the diffuse reflection surface 23A in the second direction N. Without direct observation, direct light directed directly from the LED group 31 toward the illumination target side is observed. There is a possibility that bright lines are generated due to the difference in the light emission direction.

  For this reason, the illuminating device according to the present embodiment further includes a light diffusing unit between the plurality of reflectors 23 and the illumination target, and alleviates the bright lines caused by the difference in the light emission direction between the direct light and the reflected light. It is comprised as follows.

FIG. 10 shows a configuration example in which a direction selective diffusion sheet 25 is disposed as a light diffusing unit.
The direction-selective diffusion sheet 25 is a film-like sheet having an angle dependency in transparency so that the transparency when viewed from another direction is lower than the transparency when viewed from a certain direction. An example of an optical film having such characteristics is Sumitomo Chemical Co., Ltd. Lumisty. Direct light is reflected in the direction in which reflected light is directed in the direction in which the transparency in the direction-selective diffusion sheet 25 is increased (the haze value is decreased) (first direction M), and the direction in which the transparency is decreased (the haze value is increased). The bright lines can be alleviated by arranging them so as to be in the direction (second direction N) toward.

FIG. 11 shows a configuration example in which a prism sheet 26 is disposed as a light diffusing unit.
The prism sheet 26 has a plurality of minute prisms 26A formed on the surface thereof at a predetermined pitch, for example, at equal intervals. The micro prism 26A has a substantially triangular cross section, a first surface 26M disposed in the first direction M to which the reflected light travels, and a second surface disposed in the second direction N to which the direct light travels. 26N. The transparency of the second surface 26N is lower than that of the first surface 26M. Such a configuration can be realized, for example, by blasting the second surface 26N to roughen the surface.

  Note that when the lighting device according to this embodiment is used as a backlight of a display device, for example, the direction 41 in the figure is preferably on the lower side and the direction 42 in the figure is on the upper side. In general, in the case of a display device for television use or the like, it is often considered that the viewing form is such that the display device is looked up from a slightly lower side. In such a case, by arranging the direction 41 in the figure on the lower side, the light from the first direction M side is dominantly observed, so that the luminance can be observed well.

It should be noted that similar light diffusing means can be arranged in the configuration examples according to the first, third, and fourth embodiments.
[Sixth Embodiment]

  Next, a sixth embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as each above-mentioned embodiment, and description is abbreviate | omitted suitably.

As in the fifth embodiment, the present embodiment relates to a configuration for reducing the difference in luminance depending on the observation direction. FIG. 12 shows a configuration example of the lighting apparatus according to the present embodiment.
This illuminating device includes a prism sheet 27 having a plurality of prismatic grooves formed on the surface as the light diffusing means described in the fifth embodiment, and a predetermined distance d on the illumination target side with respect to the prism sheet 27. And a diffusing plate 10 that is disposed opposite to each other and diffuses light incident through the prism sheet 27 uniformly.

  As shown in an enlarged view in FIG. 14, the prism sheet 27 has a plurality of triangular microprisms 27A formed on the surface. Here, as shown in FIG. 13, when a light beam enters a medium (for example, transparent resin) having a refractive index n0 from a medium (for example, air) having a refractive index n0, the light beam incident at an angle α is refracted at an angle β. The prism sheet 27 is configured to relieve the difference in the light emission direction between the direct light and the reflected light by the refraction effect of the microprism 27A.

  The minute prism 27A has a first surface 27M disposed in a first direction M where reflected light travels, and a second surface 27N disposed in a second direction N where direct light travels. The transparency of the first surface 27M and the second surface 27N of the minute prism 27A is the same. Here, the prism sheet 27 appropriately adjusts the apex angle θ1 of the microprism 27A and the angles θ2 and θ3 formed between the adjacent first surface 27M and the second surface 27N so that the incident light beam is directed toward the center. It is possible to correct J and emit the light.

  For example, if the first direction M in which the reflected light is directed and the second direction N in which the direct light is directed are substantially symmetric, the micro prism 27A is set at an angle θ2 = θ3 as in the configuration example illustrated in FIG. The light emission direction can be appropriately corrected by appropriately setting the refractive index of the minute prism 27A. On the other hand, if the first direction M in which the reflected light is directed and the second direction N in which the direct light is directed are asymmetric, the angle θ2 and the angle θ3 are made different from each other as in the configuration example illustrated in FIG. The configuration of the prism 27A may be an asymmetric shape.

  FIG. 16 shows the effect of the light diffusing means in the present embodiment. In the present embodiment, first, the difference in the light emission direction between the reflected light and the direct light is corrected by the refraction effect in the prism sheet 27, so that the light emission directions are substantially the same. The light beam density is substantially uniformized in the region between the prism sheet 27 and the diffusion plate 10 by sufficiently taking the interval d from the prism sheet 27 to the diffusion plate 10. Further, the light diffuses by passing through the diffusion plate 10, and the uneven brightness is alleviated. Thereby, the bright line due to the difference in the light emission direction is alleviated.

  Since the prism has a reflection effect in addition to the refraction effect, depending on the angle of the incident light, for example, as shown in FIG. 17, the first surface 27M and the second surface 27N of the minute prism 27A The light beam may be recursively incident on the diffuse reflection surface 23A of the reflector 23. Thereby, the effect which improves color mixing property more is anticipated.

  Note that when the lighting device according to this embodiment is used as a backlight of a display device, for example, the direction 41 in FIG. 12 may be arranged on the lower side, and the direction 42 in the drawing may be arranged on the upper side. In general, in the case of a display device for television use or the like, it is often considered that the viewing form is such that the display device is looked up from a slightly lower side. In such a case, by arranging the direction 41 in the figure on the lower side, the light from the first direction M side is dominantly observed, so that the luminance can be observed well.

It should be noted that similar light diffusing means can be arranged in the configuration examples according to the first, third, and fourth embodiments.
[Seventh Embodiment]

  Next, a seventh embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as each above-mentioned embodiment, and description is abbreviate | omitted suitably.

The present embodiment relates to a configuration for reducing the difference in luminance depending on the observation direction, as in the sixth embodiment. FIG. 18 illustrates a configuration example of the lighting device according to the present embodiment.
This illuminating device is provided with a Fresnel lens sheet 28 in place of the prism sheet 27 (FIG. 12) in the sixth embodiment.

  As shown in an enlarged view in FIG. 19B, the Fresnel lens sheet 28 has a plurality of Fresnel lenses 28A formed on the surface. The Fresnel lens 28 </ b> A has a concave shape as a whole and has a lens action as the concave lens 29 by forming concentric grooves on the surface. As shown in an enlarged view in FIG. 19A, the Fresnel lens 28A has such a shape that the undulation of the groove increases as it goes from the central part to the peripheral part. The Fresnel lens sheet 28 is configured to relieve the light and darkness of the light beam due to the difference in the light beam emission direction between the direct light and the reflected light due to the refraction effect of the Fresnel lens 28A. In order to alleviate the brightness and darkness of the brightness, the Fresnel lens sheet 28 is adjusted so that a light beam as a bright portion is incident on the central portion of the Fresnel lens 28A and a light beam as a dark portion is incident on the peripheral portion of the Fresnel lens 28A. Place.

  FIG. 20 shows the effect as the light diffusing means in the present embodiment. In the present embodiment, first, due to the refraction effect in the Fresnel lens sheet 28, the light and darkness of the light flux due to the difference in the light emission direction between the reflected light and the direct light is corrected. That is, the light beam of the bright part incident on the central part of the Fresnel lens 28A is distributed to the peripheral part of the Fresnel lens 28A, and the bright part and the dark part are neutralized, thereby correcting light and dark. Then, by sufficiently taking a distance d from the Fresnel lens sheet 28 to the diffuser plate 10, the light density is made substantially uniform in a region between the Fresnel lens sheet 28 and the diffuser plate 10. Further, the light diffuses by passing through the diffusion plate 10, and the uneven brightness is alleviated. Thereby, the bright line due to the difference in the light emission direction is alleviated.

  Note that when the lighting device according to this embodiment is used as a backlight of a display device, for example, the direction 41 in FIG. 18 may be arranged on the lower side and the direction 42 in the drawing may be arranged on the upper side. In general, in the case of a display device for television use or the like, it is often considered that the viewing form is such that the display device is looked up from a slightly lower side. In such a case, by arranging the direction 41 in the figure on the lower side, the light from the first direction M side is dominantly observed, so that the luminance can be observed well.

It should be noted that similar light diffusing means can be arranged in the configuration examples according to the first, third, and fourth embodiments.
[Eighth Embodiment]

  Next, an eighth embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as each above-mentioned embodiment, and description is abbreviate | omitted suitably.

FIG. 21 shows the overall configuration of a lighting apparatus according to the eighth embodiment of the present invention.
The present embodiment relates to an illumination device configured by arranging a plurality of light source units in parallel in the same in-plane direction. The LED unit 3 is used as the light source unit. Below, the case where the illumination device (FIGS. 5A and 5B and FIGS. 6A and 6B) shown in the second embodiment is used as the LED unit 3 will be described as an example. However, it is also possible to use the illumination device according to another embodiment as the LED unit 3.

  In the configuration example of FIG. 21, the LED unit 3 includes a first direction (vertical direction (y direction in the figure)) and a second direction (horizontal horizontal direction (x direction in the figure)) orthogonal to the first direction. A total of 9 units are arranged, 3 each. Here, the arrangement area of each unit in the horizontal and horizontal directions is referred to as an A block, a B block, and a C block in order from one end (left end) side.

Here, with reference to FIG. 22, the structure of the edge part of each block is demonstrated.
As described in the second embodiment, the LED unit 3 has one LED group 31 located at one end (left end) in the horizontal direction and 1 at the other end (right end). It is assumed that the two reflectors 23 are arranged so as to be positioned. In this LED unit 3, since the reflected light of the diffuse reflection surface 23A is mainly used as illumination light, a portion corresponding to the region where the reflection plate 23 is disposed becomes a light use area as illumination light. Further, in this LED unit 3, since colored light is emitted from the side toward the diffuse reflection surface 23A, the light source arrangement area, which is the area where the LED group 31 is arranged, and the light utilization area are shifted in the horizontal direction. It has become.

  Using such an LED unit 3, two horizontally adjacent LED units 3 can be combined so as to partially overlap each other. That is, the reflecting plate 23 arranged at the other end (right end) of one adjacent LED unit 3 (for example, A block unit) and one of the other adjacent LED unit 3 (for example, B block unit). The LED group 31 disposed at the end (left end) of the LED can be combined so as to overlap in the horizontal direction. Thus, in the unit joint part 63 which is the joint between the A block and the B block and the unit joint part 64 which is the joint between the A block and the B block, two adjacent LED units 3 are partially Combined to overlap. Thereby, since illumination light is emitted also from the joint part between blocks, it can be set as the illuminating device which a joint part does not stand out.

  The LED group 31 disposed at the left end of the LED unit 3 is located at the left end of the A block (unit left end 61), and the right end of the LED unit 3 at the right end of the C block (unit right end 62). The reflector 23 arranged in the part is located. When used as a backlight of a display device, the left end portion of the A block and the right end portion of the C block are preferably set as offset areas and arranged outside the effective screen.

FIG. 23 shows a configuration example when used as a backlight of a display device.
In this backlight, the entire lighting device shown in FIG. 21 is accommodated in one backlight box 4. A diffusion plate 10 is disposed on the upper surface of the backlight box 4. In FIG. 23, LED units 3A, 3B, and 3C correspond to the A block, B block, and C block of FIG. 21, respectively.

  The prism sheet 27 (FIG. 12) in the sixth embodiment and the Fresnel lens sheet 28 (FIG. 18) in the seventh embodiment are arranged above the LED units 3A, 3B, 3C. May be. In this case, the luminance unevenness can be reduced satisfactorily by taking a sufficient distance d between them and the diffusion plate 10.

Note that the unit-type lighting device in the present embodiment is particularly suitable as a partially driven LED backlight. In the partial-drive LED backlight, the light emission area of the entire screen is divided into a plurality of areas, and the light emission control can be performed independently for each area. In a display device using a partial drive type LED backlight, the luminance of the backlight can be partially changed according to the image to be displayed, so that a higher quality image can be displayed.
[Other embodiments]

The present invention is not limited to the above embodiments, and other modifications can be made.
For example, in the first embodiment, the example of the liquid crystal display device (FIG. 4) is shown as the display device, but the illumination device of the present invention can also be applied to display devices other than the liquid crystal display device. Further, the lighting device of the present invention can be used for purposes other than the backlight of the display device.

It is a block diagram which shows the basic principle of the illuminating device which concerns on the 1st Embodiment of this invention. It is side sectional drawing which shows an example of the illuminating device which concerns on the 1st Embodiment of this invention. It is explanatory drawing which expanded and showed the lens sheet part in the illuminating device shown in FIG. It is a whole block diagram which shows an example of the display apparatus using the illuminating device which concerns on the 1st Embodiment of this invention. It is a figure which shows the example of 1 structure of the illuminating device which concerns on the 2nd Embodiment of this invention, (A) is the side sectional drawing, (B) is explanatory drawing which shows arrangement | positioning of LED. It is a figure which shows the example of 1 structure of the illuminating device which concerns on the 2nd Embodiment of this invention, (A) is the top view, (B) is the sectional side view. It is a top view which shows an example of the illuminating device which concerns on the 3rd Embodiment of this invention. It is a figure which shows the example of 1 structure of the illuminating device which concerns on the 4th Embodiment of this invention, (A) is the top view, (B) is the sectional side view. It is explanatory drawing which shows the problem of the appearance by the difference in an observation direction. It is side sectional drawing which shows the basic composition of the illuminating device which concerns on the 5th Embodiment of this invention. In the illuminating device which concerns on the 5th Embodiment of this invention, it is a sectional side view which shows the structural example using a prism sheet. It is side sectional drawing which shows an example of the illuminating device which concerns on the 6th Embodiment of this invention. It is explanatory drawing about Snell's law. It is explanatory drawing which shows the basic effect | action of a prism sheet. It is explanatory drawing which shows the modification of a prism sheet. It is side sectional drawing which shows the effect | action and effect of the illuminating device which concerns on the 6th Embodiment of this invention. It is explanatory drawing which shows the effect | action of the double reflection by a prism sheet. It is side sectional drawing which shows an example of the illuminating device which concerns on the 7th Embodiment of this invention. It is explanatory drawing about a Fresnel lens sheet. It is side sectional drawing which shows the effect | action and effect of the illuminating device which concerns on the 7th Embodiment of this invention. It is a perspective view which shows the whole structure of the illuminating device which concerns on the 8th Embodiment of this invention. It is explanatory drawing which shows an example of the connection method of the LED unit in the illuminating device which concerns on the 8th Embodiment of this invention. It is side sectional drawing which shows an example of the backlight box using the illuminating device which concerns on the 8th Embodiment of this invention.

Explanation of symbols

  LB ... Blue light, LG ... Green light, LR ... Red light, M ... First direction (reflected light side), N ... Second direction (direct light side), 1 ... Backlight, 2 ... Liquid crystal panel, 3 (3A, 3B, 3C) ... LED unit, 4 ... backlight box, 10 ... diffuser plate, 11, 13 ... light source group, 11R, 13R ... red light source, 11G, 13G ... green light source, 11B, 13B ... blue light source, 12R, 12G, 12B, 14R, 14G, 14B ... condensing mirror, 15, 16 ... reflector, 15A, 16A ... diffuse reflection surface, 17 ... mixed color light (white light), 18 ... housing, 21 ... LED group, 21R ... Red LED, 21G ... Green LED, 21B ... Blue LED, 22 ... Condensing lens sheet, 23 ... Reflector, 23A ... Diffuse reflection surface, 24 ... Mixed color light (white light), 25 ... Direction selective diffusion sheet, 26 ... Prism sheet, 26A ... Small prism, 26M ... first surface, 26N ... second surface, 27 ... prism sheet, 27A ... micro prism, 27M ... first surface, 27N ... second surface, 28 ... Fresnel lens sheet, 28A ... Fresnel Lens, 29 ... concave lens, 30 ... light emitting surface, 31 ... LED group (side emission type), 31A ... electrode, 31R ... red LED, 31G ... green LED, 31B ... blue LED, 32 ... condensing lens sheet, 51 ... LED Group (top emission type), 51R ... red LED, 51G ... green LED, 51B ... blue LED, 61 ... unit left end, 62 ... unit right end, 63, 64 ... unit joint.

Claims (15)

A light source group including a plurality of light sources each emitting different colored light;
The surface is a diffuse reflection surface inclined at a predetermined angle, and each color light emitted from the light source group is incident on the same part of the diffuse reflection surface from the side surface direction, and each incident color light is A luminaire comprising: a reflector that mixes colors and reflects the illuminating light to the illumination target side. A plurality of the reflection plates and the light source groups, the reflection plates and the light source groups are alternately arranged in parallel in the same in-plane direction, and the lateral direction with respect to each of the plurality of reflection plates A group of light sources,
In each of the diffuse reflection surfaces of the plurality of reflection plates, each color light is incident from the side surface direction, and the incident color light is mixed and reflected as illumination light. The lighting device according to claim 1. Further comprising light diffusing means disposed between the plurality of reflectors and the illumination target,
The light beam diffusing means is a light beam emitting direction of direct light that is directly reflected from the light source group toward the illumination target side without being reflected by the diffuse reflection surface and reflected light that is reflected by the diffuse reflection surface and directed toward the illumination target side. The illuminating device according to claim 2, wherein the lighting device is configured to reduce a bright line caused by the difference. The light diffusing means is a film-like sheet having an angle dependency on transparency such that the transparency when viewed from the second direction is lower than the transparency when viewed from the first direction,
The said film-like sheet | seat is arrange | positioned so that the said 1st direction turns into the direction where the said reflected light goes, and the said 2nd direction turns into the direction where the said direct light goes. Lighting equipment. The light diffusing means is a prism sheet having a plurality of prisms formed on the surface,
The prism formed on the surface of the prism sheet includes a first surface disposed in a first direction toward which the reflected light travels and a second surface disposed in a second direction toward which the direct light travels. The lighting device according to claim 3, wherein the second surface is less transparent than the first surface. As the light diffusing means,
A prism sheet having a plurality of prismatic grooves formed on the surface;
The diffusion plate according to claim 3, further comprising a diffusing plate that is disposed to face the illumination target side with a predetermined interval with respect to the prism sheet and that uniformly diffuses light incident through the prism sheet. Lighting device. The prism sheet has a plurality of triangular microprisms formed on the surface,
The illumination device according to claim 6, wherein the illumination device is configured to reduce a difference in a light emission direction between the direct light and the reflected light by a refraction effect of the microprism. The prism sheet is a Fresnel lens sheet in which a plurality of concave Fresnel lenses are formed on the entire surface,
The illumination device according to claim 6, wherein the lighting device is configured to relieve light and darkness of a light beam due to a difference in a light emission direction between the direct light and the reflected light by a refractive effect of the Fresnel lens. A condensing element arranged between the light reflector group and the light source group arranged corresponding to the reflector plate, and condenses the color lights from the light source group on the same part of the diffuse reflection surface of the reflector plate. The lighting device according to claim 2, further comprising means. Each light source in the light source group emits each color light in a side surface direction,
In the light source group, at least one of the plurality of light sources is inclined and arranged in a horizontal plane so that the respective color lights from the light source group are condensed on the same portion of the diffuse reflection surface of the reflector. The lighting device according to claim 2. Each light source in the light source group emits each color light in a top surface direction,
In the plurality of reflectors, the back surface side of the diffuse reflection surface is a reflection surface,
The light source group is disposed on the back surface side of the reflecting plate, and each color light emitted from the light source group is reflected by the reflecting surface on the back surface side of the reflecting plate, and then the other reflecting plate adjacent thereto It is comprised so that it may inject into a diffuse reflection surface. The illuminating device of Claim 2 characterized by the above-mentioned. An illumination device configured by arranging a plurality of light source units in parallel in the same in-plane direction,
The lighting device according to claim 2, wherein each of the plurality of light source units includes a plurality of the reflection plate and the light source group. A plurality of the light source units are arranged at least in the horizontal direction;
Each light source unit has the light source group disposed at one end in the horizontal direction, and the reflector is disposed at the other end in the horizontal direction.
Arbitrary two light source units adjacent in the horizontal direction are disposed at the one end of the other light source unit and the reflector disposed at the other end of the adjacent one light source unit. The lighting device according to claim 12, wherein the light source group is combined so as to overlap in a horizontal direction. Each of the plurality of light source groups includes a first light source that emits first color light, a second light source that emits second color light, and a third light source that emits third color light. Or a third light source is arranged in the first direction, and
The plurality of light source groups are arranged in a second direction orthogonal to the first direction, and the order of arrangement of the first to third light sources differs between the adjacent light source groups, and the second The lighting device according to claim 2, wherein the first to third light sources appear alternately in a direction. A display device comprising: an illumination device; and a display unit that displays an image using illumination light from the illumination device as display light,
The lighting device includes:
A light source group including a plurality of light sources each emitting different colored light;
The surface is a diffuse reflection surface inclined at a predetermined angle, and each color light emitted from the light source group is incident on the diffuse reflection surface from the side surface direction, and the incident color light is mixed. A display device comprising: a reflector that reflects the illumination light toward the illumination target side.

Images