JP2006066121A - Light source device, electro-optical device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device, an electro-optical device, and an electronic apparatus capable of enhancing the uniformity of color of irradiation light as a whole. <P>SOLUTION: The device is provided with a diffusion degree adjusting means 3 equipped with at least two diffusion regions 3a, 3b, 3c different in diffusion degrees, that is degrees of diffusing light, and at least two diffusion regions 3a, 3b, 3c of the diffusion degree adjustment means 3 are so structured as to have light of different colors irradiated for each region. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light source device, an electro-optical device, and an electronic apparatus.

  In recent years, liquid crystal display devices such as liquid crystal panels have been used by being mounted on image display units of various electronic devices. In particular, a liquid crystal display device is preferably used for a display unit of a mobile device such as a mobile phone because of its advantage of being thin and light and having low power consumption. The liquid crystal display device mainly includes a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of substrates, and a light source device (backlight) disposed on the non-observation surface side of the liquid crystal panel. Then, an electric field is applied to the liquid crystal layer by the transparent electrode formed on the liquid crystal layer side of the pair of substrates to control the alignment state of the liquid crystal molecules, thereby modulating the incident light from the light source device to display an image. It has a configuration.

The light source device described above mainly includes a rectangular light guide plate made of a light transmissive material and a light source such as a light emitting diode (LED) disposed on a side surface (end surface) of the light guide plate. The light guide plate is formed with a groove or a protruding pattern. Then, the light source light emitted from the light source and incident from the side surface of the light guide plate is reflected by the groove or projecting shape, and is emitted from the main plane of the light guide plate toward the liquid crystal panel (for example, Patent Documents). 1). Conventionally, there is a light source device in which point light sources of different emission colors are arranged in the vicinity of the side surface of the light guide plate. This is to mix different emission colors in the light guide plate and to make light irradiation from the light exit surface of the light guide plate into white light with uniform luminance (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 2001-133776 JP 11-353920 A

  However, the conventional light source device has a problem that the color distribution of light emitted from the entire light guide plate is not uniform. For example, it is assumed that blue light, green light, and red light are incident on the light guide plate from three types of LED light sources. In the conventional light guide plate, a plurality of irregularities are distributed and arranged at a constant density on the bottom face body. Then, the blue light incident on the light guide plate has a shorter wavelength than the other green light and red light, and thus has a large scattering. On the other hand, since the red light incident on the light guide plate has a longer wavelength than other blue light and green light, scattering is small. As a result, in the conventional light source device, the luminance distribution of the light of each color is significantly different within the light guide plate, and white light with a uniform color distribution cannot be emitted. Therefore, a liquid crystal display device using such a light source device as a backlight cannot display a high-quality color image.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a light source device, an electro-optical device, and an electronic apparatus that can improve color uniformity for the entire emitted light.
Another object of the present invention is to provide a light source device, an electro-optical device, and an electronic apparatus that can improve color uniformity with respect to the entire emitted light with a simple configuration.

In order to achieve the above object, the light source device of the present invention has diffusivity adjusting means having at least two diffusion regions having different diffusivities, which are the degree of diffusing light. At least two diffusion regions are configured to be irradiated with light of different colors for each diffusion region.
Here, it is preferable that the diffusion regions are arranged as close as possible to each other.
According to the present invention, for example, the diffusivity is decreased in a diffusion region irradiated with blue light having a relatively short wavelength, and the diffusivity is increased in a diffusion region irradiated with red light having a relatively long wavelength. In the diffusion region irradiated with the medium green light, the diffusion degree can be made medium. Here, when light of each color is irradiated onto a diffusion plate having a constant diffusivity, blue light is easy to diffuse, red light is difficult to diffuse, and green light is medium. Therefore, according to the present invention, the scattering state (for example, luminance distribution) of the light of each color diffused by the diffusivity adjusting means can be made to substantially coincide with each other. If the diffusion regions of the diffusivity adjusting means are arranged close to each other, the lights of the respective colors diffused by the diffusivity adjusting means are combined and combined light having a uniform color distribution (for example, the entire emission surface) (White light of uniform color) can be emitted.
More specifically, the diffusion degree in the present invention is defined as follows. When light having a reference wavelength (for example, green light) is incident on the diffusivity adjusting means (diffusion region), the light emitted from the diffusivity adjusting means in the same direction as the incident direction is set as non-scattered light, Light emitted from the diffusivity adjusting means in different directions is referred to as scattered light. The intensity of the scattered light is I1, and the intensity of the non-scattered light is I2. The diffusivity in this case is
Diffusivity (%) = {I1 / (I1 + I2)} × 100
Expressed as

In order to achieve the above object, a light source device of the present invention is a light source device that causes light from a plurality of light sources to enter from a side surface of a light guide plate and to exit from one main plane of the light guide plate, and diffuses light. A diffusivity adjusting means having at least two diffusion regions with different diffusivities, which is a degree to which the plurality of light sources emit light of at least two different colors, and the diffusivity adjusting means includes: Each of the at least two diffusion regions is arranged and configured to irradiate one of the different color lights, and the light diffused by the diffusivity adjusting means is emitted from the light guide plate. It is the structure.
According to the present invention, for example, the diffusivity can be reduced in a diffusion region irradiated with light having a relatively short wavelength, and the diffusivity can be increased in a diffusion region irradiated with light having a relatively long wavelength. Therefore, according to the present invention, the scattering state of the light of each color diffused by the diffusivity adjusting means can be made substantially coincident with each other. Here, since the light of each color diffused by the diffusivity adjusting means is emitted from the light guide plate, the present invention can make the color distribution of the emitted light uniform throughout the light guide plate.

In the light source device of the present invention, the at least two diffusion regions of the diffusivity adjusting means have a first diffusion region and a second diffusion region, and the wavelength intensity characteristic of the light source irradiated to the first diffusion region in the previous period. Is configured to be irradiated with a light source having a peak on the short wavelength side with respect to the second diffusion region, and the diffusivity of the first diffusion region is preferably smaller than the diffusivity of the second diffusion region. .
According to the present invention, for example, the first diffusion region of the diffusivity adjusting means is irradiated with blue light having a relatively short wavelength, and the second diffusion region is irradiated with red light having a relatively long wavelength. Can do. Here, since the diffusivity of the first diffusion region is smaller than the diffusivity of the second diffusion region, it is possible to match the scattering state of the blue light and the scattering state of the red light after being diffused by the diffusivity adjusting means. it can. Therefore, the present invention can make the color distribution of the entire emitted light uniform.

In the light source device of the present invention, it is preferable that the diffusivity of each of the at least two diffusion regions of the diffusivity adjusting means is a diffusivity with a value approximately proportional to the irradiation of the diffusion region.
According to the present invention, the light scattering states of the respective colors after being diffused by the diffusivity adjusting means can be made to substantially coincide with each other. Therefore, the present invention can make the color distribution uniform for the entire emitted light of the light source device, which is the combined light of the light of each color after being diffused by the diffusivity adjusting means.

Further, in the light source device of the present invention, the diffusivity adjusting means sets the diffusivity of the diffusion region so that the scattering state of the light of each color diffused in each of the at least two diffusion regions is substantially the same. It is preferable that
According to the present invention, since the luminance distribution of each color light after being diffused by the diffusivity adjusting means can be made uniform, the color distribution of the combined light of each color light can be made uniform.

In the light source device of the present invention, the diffusivity adjusting means has a plurality of uneven shapes formed on a light source side surface of the light guide plate, and each of the at least two diffusion regions has the plurality of uneven shapes. It is preferable that the diffusion region has a density or shape corresponding to the degree of diffusion.
According to the present invention, light that enters the light guide plate from the side surface of the light guide plate can be diffused (within the light guide plate) with a degree of diffusion corresponding to the color (wavelength) of the light. Therefore, according to the present invention, the light scattering state of each color in the light guide plate can be made uniform, and the color distribution of emitted light in the entire light guide plate can be made uniform. Here, the magnitude of the diffusivity can be adjusted by the density of the plurality of irregularities formed on the side surface on the light source side or the shape itself. For example, when increasing the diffusivity, the density of the uneven shape is increased, and when decreasing the diffusivity, the density of the uneven shape is decreased.

In the light source device of the present invention, the light guide plate is manufactured using a mold, and the mold has a shape corresponding to the uneven shape of the diffusivity adjusting means. preferable.
According to the present invention, the light guide plate provided with the diffusivity adjusting means can be simply configured by dissolving the constituent material of the light guide plate and putting it in a mold. Here, the process using the mold is a process used even when the diffusivity adjusting means is not provided. Therefore, the present invention can provide a light source device that can be manufactured without increasing the number of steps with respect to the conventional light guide plate manufacturing process and light source device manufacturing process, and can make the color distribution of emitted light uniform.

In the light source device of the present invention, it is preferable that the diffusivity adjusting means is formed by blasting.
According to the present invention, for example, a light guide plate with diffusivity adjusting means can be configured simply by performing blasting by spraying an abrasive on the side surface of the light guide plate. Here, the adjustment of the diffusivity can be easily handled by changing the surface roughness of the side surface of the light guide plate, for example, by changing the particle size of the abrasive or adjusting the jet pressure. Moreover, when manufacturing a light-guide plate using a type | mold, a diffusivity adjustment means may be comprised by blasting about the type | mold, providing an unevenness | corrugation, and transferring the unevenness | corrugation to a light-guide plate.

In the light source device of the present invention, the diffusivity adjusting means includes a plurality of prisms formed on a light source side surface of the light guide plate, and each of the at least two diffusion regions includes the plurality of prisms. It is preferable that it is configured to have a density or shape corresponding to the degree of diffusion.
According to the present invention, for example, by forming a plurality of prisms having a triangular cross section on the side surface of the light guide plate, the diffusivity adjusting means can be configured on the side surface. Here, the magnitude of the diffusivity can be adjusted by the angle of the apex angle or the length of each side of the triangular wave shape.

Further, in the light source device of the present invention, the diffusivity adjusting means is made of a sheet member, and at least one surface of the sheet member is formed with a plurality of irregularities or a plurality of prisms, and the at least two diffusion regions It is preferable that each of the plurality of concave and convex shapes or the plurality of prisms has a density or shape corresponding to the degree of diffusion of the diffusion region.
ADVANTAGE OF THE INVENTION According to this invention, the light source device which can aim at uniformization of color distribution of emitted light simply can be provided by affixing the said sheet | seat member on the existing light-guide plate.

In the light source device of the present invention, it is preferable that the sheet member includes a sheet in which the at least two diffusion regions are formed.
ADVANTAGE OF THE INVENTION According to this invention, the light source device which can aim at uniformization of color distribution of emitted light simply can be provided by sticking one sheet | seat (sheet | seat member) to the existing light-guide plate.

The light source device of the present invention includes a plurality of unit light sources each including a plurality of light emitting units that emit light having different peak wavelengths, and the light having different peak wavelengths is the peak light source. It is preferable that the diffusion region having a diffusivity corresponding to the wavelength is irradiated.
According to the present invention, for example, the light emitting unit of the unit light source includes the first, second, and third light emitting units, the light of the first light emitting unit has a peak at a short wavelength, and the light of the second light emitting unit has a short wavelength. It may have a peak in the middle of the long wavelength, and the light of the third light emitting unit may have a peak at the long wavelength. According to the present invention, the diffusivity is reduced in the diffusion region irradiated with the light (for example, blue) of the first light emitting unit, and the diffusivity is set in the diffusion region of the third light emitting unit (for example, red). And the diffusion degree can be made medium in the diffusion region irradiated with the light (for example, green) of the second light emitting unit. Therefore, according to the present invention, the light scattering state (for example, luminance distribution) of each light source diffused by the diffusivity adjusting means can be made to substantially coincide with each other. When the diffusion regions of the diffusivity adjusting means are arranged close to each other, the light of each light source diffused by the diffusivity adjusting means is combined and combined light with a uniform color distribution (for example, the entire emission surface) White light in a uniform state) can be emitted.

Further, the light source device of the present invention has a configuration in which the light diffused by the diffusivity adjusting means is incident on the light guide plate and then emitted from the light guide plate, and the light emitted from the light guide plate is It is preferable that the color is almost white.
According to the present invention, for example, a light source device suitable as a backlight of a wide color gamut liquid crystal display device can be provided.

In order to achieve the above object, an electro-optical device of the present invention includes the light source device.
According to the present invention, for example, by using the light source device as a backlight of an electro-optical device such as a liquid crystal display device, it is possible to provide an electro-optical device that can display a color image with high quality without color unevenness.

In order to achieve the above object, an electronic apparatus according to an aspect of the invention includes the electro-optical device.
According to the present invention, an electronic apparatus including an electro-optical device that can display a color image with high quality can be provided at low cost.

  Hereinafter, a light source device and an electro-optical device according to embodiments of the invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing an example of a light source device according to the first embodiment of the present invention. FIG. 2 is a plan view of the light source device shown in FIG. 3 is a partially enlarged cross-sectional view of the light source device shown in FIG. The light source device 10A of this embodiment is used as a backlight of a liquid crystal display device, for example. The light source device 10 </ b> A includes a plurality of light sources 1 </ b> A (unit light sources) and a light guide plate 2. And, on the side surface of the light guide plate 2, a diffusivity adjusting means 3 composed of diffusion regions 3a, 3b, 3c is formed.

  The light source 1A shall be comprised by LED, for example. The light source 1A includes a blue LED (B, first light emitting unit) that emits blue light having a peak wavelength of about 470 nm and a green LED (G, second light) that emits green light having a peak wavelength of about 520 nm. A light emitting unit) and a red LED (R, third light emitting unit) that emits red light having a peak wavelength of about 620 nm is incorporated in one package. The blue LED (B) is arranged near one lower end of the package, the green LED (G) is arranged near the other lower end of the package, and the red LED (R) is arranged on the upper side of the package. It is arranged near the center. Here, it is preferable that the blue LED (B), the green LED (G), and the red LED (R) are arranged close to each other.

  Here, the light source 1 </ b> A may be configured by other than the LED, and for example, the light source 1 </ b> A may be configured by a semiconductor laser such as an organic electroluminescence element, an edge emitting semiconductor laser, or a surface emitting semiconductor laser. Further, the light source 1A may be constituted by a cold cathode tube. Each light source 1A may be mounted and mounted on a substrate. As the substrate, an FPC (Flexible Printed Circuit) is preferably used. The FPC is a flexible circuit board, and it is preferable that a drive circuit for the light source 1A and the like be mounted in addition to the light source 1A. When an FPC is used as a substrate on which the light source 1A is mounted in this way, for example, by providing a bent portion between the arrangement region of the light source 1A and the arrangement region of the drive circuit on the substrate, the degree of freedom of member arrangement can be increased. The light source device 10A can be made compact and diversified in design. Moreover, by attaching each light source 1A on a board | substrate, each light source 1A can be arrange | positioned simply and with high precision.

  The light source 1 </ b> A is disposed so as to face the side surface (end surface) of the light guide plate 2. That is, the light source 1A and the light guide plate 2 are arranged so that the light emission surface of the light source 1A and the side surface of the light guide plate 2 face each other. Accordingly, the light emitted from the light source 1 </ b> A enters the light guide plate 2 from the side surface of the light guide plate 2. Here, the light source 1A and the side surface of the light guide plate 2 are arranged with a gap. This is due to design or manufacturing limitations. In addition, a plurality of light sources 1 </ b> A are disposed on one side surface of the light guide plate 2 at substantially equal intervals.

  The light guide plate 2 is a plate material made of a light transmissive material such as acrylic resin, and has a thickness of about 0.6 mm, for example. A plurality of convex or groove-shaped prisms are formed on the bottom surface (the lower surface in the drawing) of the light guide plate 2. By this prism, the light emitted from the light source 1A and entering the light guide plate 2 from the side surface of the light guide plate 2 is reflected in the upper surface direction (upward in the drawing) of the light guide plate 2. Since the liquid crystal panel is disposed on the light guide plate 2, the light emitted from the light guide plate 2 irradiates the liquid crystal panel. Moreover, as shown in FIG. 2, the area | regions other than the outer edge in the light-guide plate 2 become the effective light emission area 2a.

  The diffusivity adjusting means 3 composed of diffusion regions 3a, 3b, 3c formed on the side surface of the light guide plate 2 diffuses the incident light with a diffusivity corresponding to the color (wavelength) of the incident light. Here, the diffusion degree is a degree of diffusing light.

FIG. 4 is a diagram for explaining the definition of the degree of diffusion. As shown in FIG. 4, the incident light of the diffusivity adjusting means 3 is L0, and the light transmitted through the diffusivity adjusting means 3 travels in the normal direction of the side surface of the light guide plate 2 (hereinafter referred to as total non-scattering). Light L2 and light L1 that is scattered by the diffusivity adjusting means 3 and travels in a direction different from the normal direction (hereinafter referred to as total scattered light) L1. The intensity of the total scattered light L1 is I1, and the intensity of the total non-scattered light L2 is I2. Then, the diffusivity is defined by the following formula (1).
Diffusivity (%) = {I1 / (I1 + I2)} × 100 (1)

  The diffusion regions 3a, 3b, 3c of the diffusion degree adjusting means 3 have different diffusion degrees. Here, the diffusion degree of the diffusion region 3a is relatively large, the diffusion degree of the diffusion region 3c is relatively small, and the diffusion degree of the diffusion region 3b is medium. Further, the diffusion region 3a is disposed at a position facing the red LED (R) of the light source 1A. The diffusion region 3b is disposed at a position facing the green LED (G) of the light source 1A. The diffusion region 3c is disposed at a position facing the blue LED (B) of the light source 1A.

  Therefore, as shown in FIGS. 2 and 3, the diffusion region 3a is irradiated with the light LR emitted from the red LED (R), and the light LR is diffused in the diffusion region 3a to be converted into the light LR ′. Propagates through the optical plate 2. The diffusion region 3b is irradiated with light LG emitted from the green LED (G), and the light LG is diffused in the diffusion region 3b and propagates in the light guide plate 2 as light LG '. Further, the light LB emitted from the blue LED (B) is irradiated to the diffusion region 3c, and the light LB is diffused in the diffusion region 3c and propagates in the light guide plate 2 as light LB '.

  Here, when the red light LR, the green light LG, and the blue light LB are diffused in, for example, the same diffusion region (for example, 3b), the red light LR has a relatively low diffusivity, and the blue light LB has a relatively large diffusion degree, and the diffusion degree of green light 1G is medium. However, in this embodiment, the diffusion region 3a is formed to have a relatively high diffusion rate, the diffusion region 3c has a relatively low diffusion rate, and the diffusion region 3b has a medium diffusion rate. Therefore, the light LR that is difficult to diffuse is diffused in the diffusion region 3a having a high diffusion degree, the light LB that is easy to diffuse is diffused in the diffusion region 3c having a low diffusion degree, and the light LG having a medium diffusion degree has a medium diffusion degree. Is diffused in the diffusion region 3b.

  Thus, according to the light source device 10A of the present embodiment, the scattering state (luminance distribution) of the light LR ′ diffused in the diffusion region 3a in the light guide plate 2 and the light LG ′ diffused in the diffusion region 3b are guided. The scattering state in the light plate 2 and the scattering state in the light guide plate 2 of the light LB ′ diffused in the diffusion region 3c substantially coincide with each other. The light LR ′, the light LG ′, and the light LB ′ are uniformly emitted from the upper surface of the light guide plate 2 in the normal direction of the upper surface by the prism formed in the light guide plate 2, and the entire emission surface is uniform. The combined light LE of the correct color. Therefore, the light source device 10A of the present embodiment can emit white light of uniform color (spectrum) without color unevenness from the entire effective light emitting area 2a.

  In the present embodiment, the diffusivity of each of the diffusion regions 3a, 3b, 3c of the diffusivity adjusting means 3 is a diffusivity with a value substantially proportional to the peak wavelength of light irradiated on the diffusion region. It is good to be. In this way, even if each light irradiated to each diffusion region 3a, 3b, 3c is not red, green, and blue, the scattering state of the light of each color after being diffused by the diffusivity adjusting means 3 is mutually determined. Therefore, light of a uniform color can be emitted over the entire effective light emitting area 2a.

(Second Embodiment)
FIG. 5 is a perspective view showing an example of a light source device according to the second embodiment of the present invention. In FIG. 5, components having the same functions as those of the light source device 10A of the first embodiment shown in FIG. The light source device 10 </ b> B of the present embodiment includes a light source 1 </ b> B and a light guide plate 2. On the side surface of the light guide plate 2, diffusivity adjusting means 3 'including diffusion regions 3a', 3b ', 3c' is formed.

  The light source device 10B of the present embodiment differs from the light source device 10A of the first embodiment in the light source 1B and the diffusivity adjusting means 3 '. The light source 1B includes a blue LED (B), a green LED (G), and a red LED (R) in one package. And while being arrange | positioned on the straight line in a blue LED (B), green LED (G), and red LED (R) package, blue LED (B) is green LED (G) near the right end in a package. Near the center of the package, the red LED (R) is disposed near the left end of the package. The light source 1 </ b> B is arranged so that the straight line formed by the arrangement of the blue LED (B), the green LED (G), and the red LED (R) is parallel to the longitudinal direction of the side surface of the light guide plate 2. The light source 1B is arranged so that the straight line on which the blue LED (B), the green LED (G), and the red LED (R) are arranged and the short side direction of the side surface of the light guide plate 2 are parallel to each other. It is good to be.

  The diffusion regions 3a ', 3b', 3c 'of the diffusivity adjusting means 3' correspond to the diffusion regions 3a, 3b, 3c of the diffusivity adjusting means 3 of the first embodiment, respectively. Therefore, the diffusion degree of the diffusion region 3a 'is relatively large, the diffusion degree of the diffusion region 3c' is relatively small, and the diffusion degree of the diffusion region 3b 'is medium. Further, the diffusion region 3a 'is disposed at a position facing the red LED (R) of the light source 1B. The diffusion region 3b 'is disposed at a position facing the green LED (G) of the light source 1B. The diffusion region 3c 'is disposed at a position facing the blue LED (B) of the light source 1B.

  Accordingly, according to the light source device 10B of the present embodiment, the light of the red LED (R) that is difficult to diffuse is diffused in the diffusion region 3a ′ having a high diffusion degree, and the light of the blue LED (B) that is easy to diffuse is diffused. The light of the green LED (G) having a medium diffusion degree is diffused in the diffusion area 3b ′ having a medium diffusion degree. Therefore, similarly to the light source device 10A of the first embodiment, the light source device 10B of the present embodiment can emit white light of uniform color with no color unevenness from the entire effective light emitting area 2a.

(Third embodiment)
FIG. 6 is a perspective view showing an example of a light source device according to the third embodiment of the present invention. In FIG. 6, components having the same functions as those of the light source device 10A of the first embodiment shown in FIG. The light source device 10 </ b> C of the present embodiment includes light sources 1 r, 1 g, 1 b and a light guide plate 2. On the side surface of the light guide plate 2, diffusivity adjusting means 3 ″ including diffusion regions 3 a ″, 3 b ″, 3 c ″ is formed.

  The light source device 10C of this embodiment is different from the light source device 10A of the first embodiment in the light sources 1r, 1g, 1b and the diffusivity adjusting means 3 ″. Each of the light sources 1r, 1g, 1b is a single LED. The light source 1r is composed of a red LED (R), the light source 1g is composed of a green LED (G), the light source 1b is composed of a blue LED (B), and the light sources 1r, 1g, 1b are composed of The light sources 1r, 1g, and 1b are arranged on a straight line at substantially equal intervals, and the straight line formed by the arrangement of the light sources 1r, 1g, and 1b and the longitudinal direction of the side surface of the light guide plate 2 are parallel to each other. The light sources 1r, 1g, and 1b are arranged so that the straight line formed by the light sources 1r, 1g, and 1b and the lateral direction of the side surface of the light guide plate 2 are parallel to each other. It is good also as being done.

  The diffusion regions 3a ", 3b", 3c "of the diffusivity adjusting means 3" correspond to the diffusion regions 3a, 3b, 3c of the diffusivity adjusting means 3 of the first embodiment, respectively. Therefore, the diffusion region 3a ″ has a relatively high diffusion degree, the diffusion region 3c ″ has a relatively low diffusion degree, and the diffusion region 3b ″ has a medium diffusion degree. Further, the diffusion region 3a ″ has a light source It is arranged at a position facing the 1r red LED (R). The diffusion region 3b ″ is disposed at a position facing the green LED (G) of the light source 1g. The diffusion region 3c ″ is disposed at a position facing the blue LED (B) of the light source 1b.

  Thus, according to the light source device 10C of the present embodiment, the light of the red LED (R) that is difficult to diffuse is diffused in the diffusion region 3a ″ having a high diffusion degree, and the light of the blue LED (B) that is easy to diffuse is diffused. Light of the green LED (G) having a medium diffusion degree is diffused in the diffusion area 3b ″ having a medium diffusion degree. Therefore, the light source device 10C of this embodiment Similar to the light source device 10 </ b> A of the first embodiment, uniform light with no color unevenness can be emitted from the entire effective light emitting area 2 a.

(Structure and manufacturing method of diffusivity adjusting means)
Next, a specific structure example and manufacturing method example of the diffusivity adjusting means 3, 3 ′, 3 ″ (hereinafter referred to as diffusivity adjusting means 3) will be described. The diffusivity adjusting means 3 is, for example, in the light guide plate 2. It is assumed that the light source side has a plurality of concave and convex shapes formed on the side surface, and diffusion regions 3a, 3b, 3c, 3a ′, 3b ′, 3c ′, 3a ″, 3b of the diffusivity adjusting means 3. ", 3c" (hereinafter referred to as diffusion region 3x) is configured such that the plurality of uneven shapes have a density or shape corresponding to the diffusion degree of the diffusion region. That is, the diffusion degree of the diffusion region 3x is set to a desired value by adjusting the density of the plurality of uneven shapes or the uneven shape itself.

  For example, when increasing the diffusivity, the density of the uneven shape is increased, and when decreasing the diffusivity, the density of the uneven shape is decreased. Further, the diffusivity may be adjusted by changing the apex angle of the triangular wave shape by making the uneven shape a triangular wave shape in cross section.

  In order to manufacture the diffusivity adjusting means 3 having the above configuration, when the light guide plate 2 is manufactured using a mold, it is possible to take a technique in which the concavo-convex shape is formed in advance on the mold and the concavo-convex shape is transferred. The uneven shape may be a so-called “texture” or may be formed by texturing. The embossing can be performed by forming a texture on a mold and transferring the texture, similarly to the above-described method for forming an uneven shape. Here, blasting can be used to form the texture in the mold. For example, a concavo-convex shape (texture) can be formed by spraying a hard white alumina (WA) -based abrasive on a mold for forming a light guide plate with a gravity or pressure blasting machine. And the unevenness | corrugation (texture) from which surface roughness differs can be formed by changing the particle size of WA type | system | group abrasive material, or adjusting a jet pressure, and a diffusivity can be adjusted.

  Further, the diffusivity adjusting means 3 may be configured by a plurality of prisms formed on the light source side surface of the light guide plate 2. The diffusion region 3x of the diffusivity adjusting means 3 is configured such that a plurality of prisms have a density or shape corresponding to the diffusivity of the diffusion region 3x.

  Moreover, you may comprise the diffusion degree adjustment means 3 with a sheet | seat member. That is, a plurality of irregularities or a plurality of prisms are formed on at least one surface of the sheet member. The diffusion degree of the diffusion region 3x can be adjusted by the uneven shape in the sheet member or the arrangement density or shape of the prisms. If it does in this way, the light source device which can aim at uniformization of the color distribution of emitted light simply can be comprised by affixing the said sheet | seat member on the existing light-guide plate. The sheet member constituting the diffusivity adjusting means 3 may be one in which a plurality of diffusion regions x are formed in one sheet, or one diffusion region x is formed in one sheet. Good.

(Electro-optical device)
FIG. 7 is a cross-sectional view illustrating an example of an electro-optical device that uses the light source device of this embodiment as a backlight. The electro-optical device constitutes a liquid crystal display device 100. The liquid crystal display device 100 includes the liquid crystal device 50 and the light source device 10A of the first embodiment shown in FIG. A liquid crystal display device 100 as a final product is configured by attaching auxiliary elements such as a liquid crystal driving IC and a support to the liquid crystal device 50 and the light source device 10A shown in FIG. The light source device 10 </ b> A of the liquid crystal display device 100 includes a first prism sheet 4, a second prism sheet 5, a reflection sheet 6, and a diffusion sheet 7.

  The diffusion sheet 7 is disposed on the upper surface (liquid crystal panel side) of the light guide plate 2. The diffusion sheet 7 is a plate-shaped sheet member that diffuses light emitted from the light guide plate 2. As the diffusion sheet 7, it is possible to use an acrylic sheet or the like in which a diffusion agent is dispersed. With this diffusion sheet 7, the surface brightness of the light emitted from the light guide plate 2 can be made more uniform, and the grooves of the first prism sheet 4 and the second prism sheet 5 and the reflection of uneven shapes (luminance unevenness) can be prevented. It is like that. The exposed area of the diffusion sheet 7 that is not covered by the first prism sheet 4 does not enter the display area (effective light emission area).

  The first prism sheet 4 is disposed on the upper surface (liquid crystal panel side) of the diffusion sheet 7. The second prism sheet 5 is disposed on the upper surface (liquid crystal panel side) of the first prism sheet 4. Each of the first prism sheet 4 and the second prism sheet 5 has a prism surface on one surface side (the upper surface side in the drawing) made of a transparent acrylic resin or the like. Formed and configured.

  FIG. 8 is a perspective view showing an example of the first prism sheet 4 and the second prism sheet 5. As shown in FIG. 8, on the prism surfaces 22a of the first prism sheet 4 and the second prism sheet 5, paired slope portions 22A and 22B are alternately and periodically formed. The angle formed by 22B (prism apex angle α) is, for example, 90 degrees. The prism apex angle α of the first prism sheet 4 and the second prism sheet 5 is not limited to 90 degrees and may be in the range of 90 degrees to 125 degrees.

  The direction in which the ridge line (peak) of the convex portion of the first prism sheet 4 extends and the direction in which the ridge line (peak) of the convex portion of the second prism sheet 5 extends are 90 degrees different from each other in the azimuth direction. Yes. Thereby, the condensing direction of the 1st prism sheet 4 and the 2nd prism sheet 5 matches the perpendicular direction (liquid crystal panel side direction) of drawing.

  The first prism sheet 4 and the second prism sheet 5 have an angle range larger than an angle range of approximately ± 20 degrees in the normal direction when light enters from the lower surface side, that is, the diffusion sheet 7 side. ) Can be changed in the traveling direction toward the top surface of the prism sheet, and the light incident on the prism sheet perpendicularly (angle range of ± 20 degrees in the normal direction) is the prism sheet. Does not pass through. In this embodiment, since the diffusion sheet 7 is disposed between the first prism sheet 4 and the light guide plate 2, the diffusion sheet 7 is perpendicular to the first prism sheet 4 and the second prism sheet 5 (± 20 degrees in the normal direction). Light incident on the angle range) can be reduced, and the light propagation efficiency can be improved.

  When the prism apex angle α of the first prism sheet 4 and the second prism sheet 5 is larger than 90 degrees, the light incident perpendicularly to the prism sheet (angle range of ± 20 degrees in the normal direction) is about Although the prism sheet may deviate greatly from the upper surface direction, it can be transmitted through the prism sheet and emitted to the liquid crystal panel side.

  FIG. 9 is a perspective view showing a prism sheet 4 ′ as another example of the first prism sheet 4 and the second prism sheet 5. The prism sheet 4 ′ is different from the first prism sheet 4 and the second prism sheet 5 shown in FIG. 8 in the shape of the prism surface.

  That is, on the prism surface 52a of the prism sheet 4 ', quadrangular pyramidal projections 52b are arranged, and adjacent projections 52b are in contact with each other at their side edges. The prism apex angle in the prism sheet 4 ′ is an angle formed by the adjacent inclined surface portion 52 </ b> A and the inclined surface portion 52 </ b> B among the inclined surface portions constituting the convex portion 52 b. The prism apex angle is preferably in the range of 95 ° to 125 ° in the prism sheet 4 '. This is because the prism sheet 4 ′ having such a configuration has a condensing function in directions parallel to the bottom sides 52 </ b> C and 52 </ b> D of the convex portion 52 b.

  Note that the configuration of the prism sheet according to the present embodiment is not limited to that shown in FIG. 8 or FIG. 9, and the shape thereof is not limited as long as the prism apex angle is in the range of 90 ° to 125 °, for example. For example, in the case of having a prism surface on which convex portions are arrayed as shown in FIG. 9, the shape of the convex portions can be a pentagonal pyramid shape, a polygonal pyramid or more, or a conical shape.

  As shown in FIG. 7, the reflection sheet 6 is disposed on the bottom surface side of the light guide plate 2 (opposite the liquid crystal panel side), and the reflection surface (upper surface) of the reflection sheet 6 and the bottom surface of the light guide plate 2 are in surface contact. is doing. According to the reflection sheet 6, it is possible to reflect the light leaking from the bottom surface of the light guide plate 2 and make it incident on the light guide plate 2 again, and increase the luminance of the light emitted from the top surface of the light guide plate 2. Can be made. Further, in the gap between the light source 1 </ b> A and the end surface of the light guide plate 2, the light L <b> 1 emitted from the light source 1 </ b> A toward the reflection plate 6 can be incident on the light guide plate 2.

  Further, the liquid crystal display device 100 of the present embodiment has a structure that prevents light emitted from the light source 1 from entering the first prism sheet 4 or the second prism sheet 5 without passing through the diffusion sheet 7. .

  That is, the planar shape of the diffusion sheet 7 is larger than the planar shapes of the first prism sheet 4 and the second prism sheet 5. The outer edge of the diffusion sheet 7 projects outward from the outer edges of the first prism sheet 4 and the second prism sheet 5. Furthermore, the diffusion sheet 7 is disposed so as to cover the entire exposed portion (portion other than the portion covered by the substrate 1a) on the upper surface of the light guide plate 2 and also cover a part of the light source 1A.

  With such a configuration, it is possible to prevent light emitted from the light source 1 </ b> A from directly entering the first prism sheet 4 or the second prism sheet 5. The light emitted from the light source 1A is diffused in the diffusion regions 3a, 3b, and 3c, and then enters the first prism sheet 4 or the second prism sheet 5 after passing through the light guide plate 2 and the diffusion sheet 7. Therefore, uniform white light can be emitted from the entire emitted light (the entire backlight) of the light source device 10A, and uneven brightness can be avoided.

  A liquid crystal device 50 shown in FIG. 7 has a pair of substrate units 13 each having a substantially rectangular shape in plan view and pasted so as to face each other with an annular sealing material 12 with a cell gap therebetween. 14, a liquid crystal layer 15 surrounded and sandwiched together with the sealing material 12 therebetween, a retardation plate 19 and a polarizing plate 16 provided on the upper surface side of one (upper side in FIG. 7) substrate unit 13, The liquid crystal panel 11 includes a retardation plate 26 and a polarizing plate 27 provided on the lower surface side of the other (lower side in FIG. 7) substrate unit 14.

  A light source device 10 </ b> A is disposed below the liquid crystal panel 11 of the liquid crystal device 50. Here, the liquid crystal device 50 and the light source device 10A are arranged so that the upper surface of the second prism sheet 5 of the light source device 10A and the lower surface of the liquid crystal panel 11 of the liquid crystal device 50 face each other. Therefore, the light source device 10 </ b> A is disposed below the liquid crystal panel 11 and can emit illumination light (backlight) from the lower side of the liquid crystal panel 11 toward the liquid crystal panel 11.

  Of the substrate units 13 and 14, the substrate unit 13 is a front (upper) substrate unit provided toward the observer side, and the substrate unit 14 is provided on the opposite side, in other words, on the back side (lower). It is. The upper substrate unit 13 includes, for example, a light-transmitting substrate 17 made of a transparent material such as glass, and a retardation plate 19 and a polarizing plate 16 that are sequentially provided on the front side (the upper surface side and the observer side in FIG. 7). And the color filter layer 24 and the overcoat layer 21 sequentially formed on the back side of the substrate 17 (in other words, the liquid crystal layer 15 side), and the liquid crystal driving surface formed on the surface of the overcoat layer 21 on the liquid crystal layer 15 side. A plurality of striped electrodes 23 are provided. The liquid crystal layer 15 is composed of nematic liquid crystal molecules having a twist angle of 240 degrees to 255 degrees.

  In an actual liquid crystal device, alignment films are respectively formed on the liquid crystal layer 15 side of the electrode 23 and the liquid crystal layer 15 side of the stripe-shaped electrode 35 on the lower substrate side. In FIG. The film is omitted and the description is omitted. In addition, the cross-sectional structure shown in each drawing including FIG. 7 is illustrated by adjusting the thickness of each layer to a thickness different from that of an actual device so that each layer can be easily seen in the drawing.

  Each of the driving electrodes 23 on the upper substrate side is formed in a stripe shape in plan view from a transparent conductive material such as ITO (Indium Tin Oxide), for example. The required number is formed according to the number of pixels.

  The color filter layer 24 is configured, for example, by forming a black mask for light shielding and RGB patterns for color display on the lower surface of the upper substrate 17 (in other words, the surface on the liquid crystal layer 15 side). . Further, an overcoat layer 21 is coated as a transparent protective flattening film for protecting the RGB pattern. The black mask is formed by patterning a metal thin film of chromium or the like having a thickness of about 100 to 200 nm by, for example, a sputtering method or a vacuum deposition method. In each of the RGB patterns, a red pattern (R), a green pattern (G), and a blue pattern (B) are arranged in a desired pattern shape. For example, a photosensitive resin containing a predetermined coloring material is used. It is formed by various methods such as a pigment dispersion method, various printing methods, electrodeposition methods, transfer methods, and dyeing methods.

  On the other hand, the lower substrate unit 14 includes a light-transmitting substrate 28 made of a transparent material such as glass, and a semi-transmissive layer sequentially formed on the surface side of the substrate 28 (the upper surface side in FIG. The reflective layer 31, the overcoat layer 33, the plurality of stripe-shaped driving electrodes 35 formed on the surface of the overcoat layer 33 on the liquid crystal layer 15 side, and the back surface side of the substrate 28 (the lower surface side in FIG. In other words, it is composed of a retardation plate 26 and a polarizing plate 27 which are sequentially formed on the side opposite to the liquid crystal layer 15 side. In these electrodes 35 as well, the necessary number is formed in accordance with the display area of the liquid crystal panel 11 and the number of pixels as in the case of the previous electrode 23.

  The light La emitted from the light source 1A of the light source device 10A is diffused by the diffusion regions 3a, 3b, and 3c, then enters the light guide plate 2, is reflected by the prism of the light guide plate 2, and is dispersed into, for example, light Lb and light Ld. Reflected. Lights Lb and Ld are incident on the diffusion sheet 7 from the light guide plate 2 and further diffused light Lc and Le and enter the first prism sheet 4 and the second prism sheet 5. Here, the lights Lc and Le are directed in the normal direction H by the first prism sheet 4 and the second prism sheet 5, respectively. These lights Lc and Le serve as a backlight and irradiate the liquid crystal device 50.

  Accordingly, the liquid crystal display device 100 according to the present embodiment has high color uniformity with respect to white light (backlight) emitted from the light source device 10A, and further has no luminance unevenness, so that a high-quality image can be displayed. .

(Electronics)
Next, an electronic apparatus including the electro-optical device (the liquid crystal display device 100) of the above embodiment as a component will be described.
FIG. 10A is a perspective view showing an example of a mobile phone. In FIG. 10A, reference numeral 500 indicates a mobile phone body, and reference numeral 501 indicates a display unit having the liquid crystal display device 100 of the above embodiment. FIG. 10B is a perspective view illustrating an example of a wristwatch type electronic device. In FIG. 10B, reference numeral 600 indicates a watch body, and reference numeral 601 indicates a display unit having the liquid crystal display device 100 of the above embodiment. FIG. 10C is a perspective view showing an example of a portable information processing apparatus such as a word processor or a personal computer. 10C, reference numeral 700 denotes an information processing apparatus, reference numeral 701 denotes an input unit such as a keyboard, reference numeral 702 denotes a display unit having the liquid crystal display device 100 of the above embodiment, and reference numeral 703 denotes an information processing apparatus main body. Show.

  Since the electronic apparatus illustrated in FIG. 10 includes the liquid crystal display device 100 according to the above-described embodiment, there is no color unevenness and luminance unevenness, and a high-quality color image with high color reproducibility can be displayed.

  The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, and the specific materials and layers mentioned in the embodiment can be added. The configuration is merely an example, and can be changed as appropriate.

  For example, in the above embodiment, RGB light sources of three primary colors are used as the light source 1A, but the present invention is not limited to this, and light sources of four primary colors or five primary colors or more can also be used. Further, the light source 1A or the like may be configured by two light sources having different emission colors. For example, when the light source 1A is configured with four primary colors, any one of cyan, magenta, and yellow is added to the RGB light source.

  In the above embodiment, an example in which the light source device according to the present invention is a constituent element of a liquid crystal display device is given. However, the present invention is not limited to this, and the light source device according to the present invention is a liquid crystal display. The present invention can be applied to various electro-optical devices and display devices other than the device. The light source device according to the present invention can be applied to an illumination device other than a display device such as an electro-optical device. Here, the illumination device is not a display device that displays an image or information, but emits predetermined light to an irradiated object.

  In the liquid crystal display device of the above embodiment, the case where the light source device of the present invention is provided in a simple matrix type transflective liquid crystal display device has been described. However, the light source device of the present invention is a two-terminal switching element. Alternatively, an active matrix type transflective liquid crystal display device including a three-terminal switching element may be provided.

It is a perspective view which shows an example of the light source device which concerns on 1st Embodiment of this invention. It is a top view of a light source device same as the above. It is a partial expanded sectional view of a light source device same as the above. It is a figure for demonstrating the definition of a diffusion degree. It is a perspective view which shows an example of the light source device which concerns on 2nd Embodiment of this invention. It is a perspective view which shows an example of the light source device which concerns on 3rd Embodiment of this invention. 1 is a cross-sectional view illustrating an example of an electro-optical device according to an embodiment of the invention. It is a perspective view which shows an example of the 1st, 2nd prism sheet | seat of an electro-optical apparatus same as the above. It is a perspective view which shows the other example of the 1st, 2nd prism sheet. It is a perspective view which shows the electronic device which concerns on embodiment of this invention.

Explanation of symbols

1A, 1B, 1r, 1g, 1b ... light source, 2 ... light guide plate, 2a ... effective light emitting area, 3,3 ', 3 "... diffusivity adjusting means, 3a, 3b, 3c, 3a', 3b ', 3c' , 3a ", 3b", 3c "... diffusion region, 10A, 10B, 10C ... light source device, 50 ... liquid crystal device, 100 ... liquid crystal display device

Claims (15)

Having a diffusivity adjusting means having at least two diffusion regions having different diffusivities, which is a degree of diffusing light,
At least two diffusion regions of the diffusivity adjusting means are configured to be irradiated with light of different colors for each diffusion region. A light source device that causes light from a plurality of light sources to enter from a side surface of the light guide plate and emit light from one main plane of the light guide plate,
Having a diffusivity adjusting means having at least two diffusion regions having different diffusivities, which is a degree of diffusing light;
The plurality of light sources emit light of at least two different colors,
The diffusivity adjusting means is arranged and configured so that one of the different color lights is irradiated for each of the at least two diffusion regions,
A light source device characterized in that the light diffused by the diffusivity adjusting means is emitted from the light guide plate. At least two diffusion regions of the diffusivity adjusting means have a first diffusion region and a second diffusion region,
The wavelength intensity characteristic of the light source irradiated to the first diffusion region in the previous period is configured such that a light source having a peak on the short wavelength side with respect to the second diffusion region is irradiated,
3. The light source device according to claim 1, wherein a diffusivity of the first diffusion region is smaller than a diffusivity of the second diffusion region.   The diffusivity of each of the at least two diffusion regions of the diffusivity adjusting means is a diffusivity having a value substantially proportional to the peak wavelength of light irradiated to the diffusion regions. The light source device according to 1.   The diffusivity adjusting means sets the diffusivity of the diffusion regions so that the scattering states of the light of each color diffused in each of the at least two diffusion regions are substantially the same. Item 3. The light source device according to Item 1 or 2. The diffusivity adjusting means comprises a plurality of concave and convex shapes formed on the light source side surface of the light guide plate,
6. Each of the at least two diffusion regions is configured such that the plurality of uneven shapes have a density or a shape corresponding to the diffusion degree of the diffusion regions. The light source device according to 1. The light guide plate is manufactured using a mold,
The light source device according to claim 6, wherein the mold has a shape corresponding to the uneven shape of the diffusivity adjusting means.   The light source device according to claim 6 or 7, wherein the diffusivity adjusting means is formed by blasting. The diffusivity adjusting means comprises a plurality of prisms formed on the side surface of the light guide plate on the light source side,
Each of the at least two diffusion regions is configured such that the plurality of prisms have a density or a shape corresponding to the diffusion degree of the diffusion regions. The light source device described. The diffusivity adjusting means comprises a sheet member,
On at least one surface of the sheet member, a plurality of irregularities or a plurality of prisms are formed,
6. Each of the at least two diffusion regions is configured such that the plurality of uneven shapes or the plurality of prisms have a density or shape corresponding to the diffusivity of the diffusion region. The light source device according to any one of the above.   The light source device according to claim 10, wherein the sheet member is formed by forming the at least two diffusion regions on a single sheet. Each has a plurality of unit light sources, each of which has a plurality of light emitting units that emit light having different peak wavelengths,
12. The structure according to claim 1, wherein the light having different peak wavelengths is irradiated to the diffusion region having a diffusivity corresponding to the peak wavelength. Light source device. The light diffused by the diffusivity adjusting means has a configuration that exits from the light guide plate after entering the light guide plate;
The light source device according to claim 1, wherein light emitted from the light guide plate is substantially white.   An electro-optical device comprising the light source device according to claim 1. An electronic apparatus comprising the electro-optical device according to claim 14.

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