JP2005189824A - Light source device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device which is inexpensive, small-sized, and low in power consumption and projects parallel luminous flux having a sufficient light quantity and uniform luminance, and the display device using the same. <P>SOLUTION: The light source device is equipped with LEDs 3<SB>1</SB>to 3<SB>3</SB>which project prescribed lights respectively, and a dichroic prism 2 which puts respective incident lights 4<SB>1</SB>to 4<SB>3</SB>from oblique surfaces 5<SB>1c</SB>, 5<SB>2c</SB>, and 5<SB>3c</SB>provided in accordance with the LEDs 3<SB>1</SB>to 3<SB>3</SB>together into one composite light 4<SB>4</SB>and projects it from one oblique surface 5<SB>4c</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light source device and a display device, and more particularly to a light source device having a plurality of point light sources and a display device using the light source device.

  A conventional light source device includes a red light source composed of a two-dimensional array of light emitting diodes (LED: Light Emitting Diodes) that are one of point light sources (for example, five horizontal elements and four vertical elements) around a dichroic prism. A green light source and a blue light source are arranged. The light emitted from the red light source and the blue light source is reflected by the red reflecting mirror and the blue reflecting mirror of the dichroic prism, respectively, and the light emitted from the green light source passes through the dichroic prism. As a result, red, green, and blue light is combined with white light and emitted from the surface of the dichroic prism where the light source is not disposed. Further, in the conventional display device, the light source device is disposed on the back surface of the liquid crystal display element, and the liquid crystal display element is illuminated with the white light, so that an observer can display the liquid crystal through a lens disposed on the front surface of the liquid crystal display element. There is one that sees an enlarged image of the element (for example, see Patent Document 1).

JP 2000-56410 A ([0053] to [0058], [0080], FIGS. 1 and 12)

  By the way, in the above-mentioned conventional light source device, since a plurality of LEDs are used, a sufficient amount of light can be secured with low cost, small size, and low power consumption. However, when this conventional light source device is used as a light source like the above-described conventional display device, there are the following disadvantages. That is, since the light beam emitted from the LED arranged other than on the optical axis of the lens and passed through the dichroic prism, the liquid crystal display element, and the lens does not become completely parallel light with respect to the optical axis due to the influence of the aberration of the lens. The luminance is not uniform, and unevenness in illuminance occurs in the image viewed by the observer. As a result, there is a problem that a high-quality video cannot be provided and the commercial value of the display device is lowered.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a light source device that can emit a parallel light beam having a uniform brightness with a sufficient amount of light with low power consumption and low power consumption. Thus, a display device capable of displaying a high-quality video without uneven illuminance is obtained.

  The light source device according to the present invention combines a plurality of point light sources each emitting a predetermined light beam and a plurality of light beams incident from a plurality of light incident surfaces provided corresponding to the respective point light sources into one light beam. And a light combining unit that emits light from one light emitting surface. According to the present invention, a sufficient amount of light (high luminous intensity) can be ensured. In addition, since the light beam incident on the light combining unit is supplied from the point light source, the combined light beam is apparently a light beam from the point light source, so that the light is parallel to the axis and has uniform luminance. It will be.

In the above apparatus, the point light source is any one of a light emitting diode, a laser diode, an electroluminescence element, and a field emission display. Thereby, the light source device can be configured with low cost, small size and low power consumption.
Further, in the above apparatus, the light combining unit is configured by a light combining unit or a combination of light combining units of either a dichroic prism or a beam splitter. Thereby, a light source device can be comprised small.
In the above-described apparatus, the light combining unit is configured such that one of the light incident surfaces of the subsequent light combining unit faces the light emitting surface of the previous light combining unit. Thereby, it is possible to provide illumination with higher and uniform luminance.

  A display device according to the present invention includes any one of the light source devices described above and an optical conversion element that modulates a light beam from the light source device based on a video signal. According to the present invention, it is possible to display a high-quality image without uneven illuminance with a simple, inexpensive, small-sized configuration and low power consumption. For this reason, the commercial value of the display device is improved.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a configuration of a light source device 1 according to Embodiment 1 of the present invention.
The light source device 1 of this example includes a dichroic prism 2 and LEDs 3 _{1 to} 3 ₃ . As shown in FIG. 2, the dichroic prism 2 is configured by bonding the right-angle surfaces of _four right-angle prisms 5 _{1 to} 5 ₄ having the same shape and the same dimensions. Rectangular prism 5 _1, the perpendicular surface 5 _1a reflective film ₆₁ is formed, the antireflection film ₇₁ is formed on the perpendicular surface 5 _1b, the antireflection film ₈₁ is formed on the inclined surface 5 _1c . Reflective film ₆₁ is formed to totally reflected to figure x + direction incident light from figure y + direction. The antireflection film 7 ₁ prevents the light reflected by the reflection film 6 ₁ and reaching the right-angle plane 5 _1a from being reflected in the y + direction in the figure, and incident light from the y + direction in the figure is x. -It is formed to prevent reflection in the direction. Antireflection film ₈₁ is formed to prevent the incident light from the drawing y + direction is reflected to figure y + direction.

Reflective film ₆₁ is, for example, a metal film or made of metal such as chromium (Cr), a dielectric multilayer film. The antireflection films 7 ₁ and 8 ₁ are made of a dielectric multilayer film. The dielectric multilayer film is formed by using, for example, a thin film of silicon dioxide (SiO ₂ ), tantalum pentoxide (CVD) using a chemical vapor deposition (CVD) apparatus or a physical vapor deposition (PVD) apparatus. For example, about 10 to 20 layers of Ta ₂ O ₅ ) or hafnium dioxide (HfO ₂ ) thin films are alternately stacked. Examples of the PVD apparatus include a sputtering apparatus, a vacuum evaporation apparatus, and an ion plating apparatus. The reflection film and the antireflection film are formed by changing the film thickness of a silicon dioxide (SiO ₂ ) thin film and a tantalum pentoxide (Ta ₂ O ₅ ) or hafnium dioxide (HfO ₂ ) thin film. Other reflective films and other antireflection films described later are also formed by the same manufacturing method.

Right-angle prism 5 _2, the antireflection perpendicular surface 5 _2a film 7 ₂ is formed, the perpendicular surface 5 _2b antireflection film 7 ₃ are formed, the inclined surface 5 _2c the antireflection film ₈₂ is formed Yes. Antireflection film 7 ₂ is formed in order to prevent the incident light from the drawing x- direction is reflected to figure y + direction. Antireflection coating 7 ₃ are formed in order to prevent the incident light from the drawing x- direction is reflected to figure y- direction. Antireflection film ₈₂ is formed to prevent the incident light from the drawing x- direction is reflected to figure x- direction.

Rectangular prism 5 _3, the antireflection perpendicular surface 5 _3a film 7 ₄ are formed, the reflection film 6 ₂ perpendicular plane 5 _3b is formed, the anti-reflection film 8 ₃ is formed on the inclined surface 5 _3c . Reflective film 6 ₂ are formed to total reflection to figure x + direction incident light from drawing in y- direction. Antireflection coating 7 _4, and to prevent the light reaching the reflected perpendicular surface 5 _3a by the reflective film 6 ₂ is reflected into the drawing y- direction, the incident light from the drawing in y- direction drawing It is formed to prevent reflection in the middle x-direction. Antireflection film 8 ₃ is formed in order to prevent the incident light from the drawing y- direction is reflected to figure y- direction.

Rectangular prism 5 _4, the perpendicular surface 5 _4a reflective film 6 ₃ are formed, the perpendicular surface 5 _4b to the reflection film 6 ₄ is formed, the inclined surface 5 _4c antireflection film 8 ₄ is formed. Reflective film 6 ₃ is formed to a total reflection to the figure x + direction incident light from drawing in y- direction. Reflective film 6 ₄ is formed in order to totally reflect the figure x + direction incident light from figure y + direction. Antireflection film 8 ₄ is formed in order to prevent the incident light from the drawing y- direction is reflected to figure y- direction.

The LEDs 3 _{1 to} 3 ₃ emit light of the same color such as white light, red light, blue light, green light, or multicolor, or separately emit red light, blue light, and green light, respectively. In addition, each of the above-described reflection films is formed so that incident light having a corresponding wavelength can be reflected according to the wavelength of the incident light, and each of the above-described antireflection films has a corresponding wavelength depending on the wavelength of the incident light. It goes without saying that the incident light is prevented from being reflected.
Therefore, for example, when synthesizing red light, the efficiency of synthesis improves when the wavelength peaks of the LEDs used for synthesis are slightly shifted. Even if the wavelength peak of each LED is the same, it can be synthesized by slightly shifting the reflection wavelength of the reflection film corresponding to each LED. This is the same in all embodiments described later.
LED 3 _1, the chip surface at a right angle prism 5 ₁ slope 5 _1c parallel and are arranged so as to face the mid-point of the line of intersection of the rectangular prism 5 ₁ perpendicular face 5 _1a and 5 _1b . LED 3 _2, the chip surface at a right angle prism 5 ₂ slopes 5 _2c parallel, and are disposed so as to face the mid-point of the line of intersection of the right-angle prism 5 ₂ perpendicular surface 5 _2a and 5 _2b . LED 3 _3, the chip surface forms a parallel to the inclined surface 5 _3c of the rectangular prism 5 _3, and is disposed so as to face the mid-point of the line of intersection of the rectangular prism 5 ₃ perpendicular surface 5 _3a and 5 _3b . That is, the LEDs 3 _{1 to} 3 ₃ are arranged on the optical axis.

Next, the operation of the light source device 1 having the above configuration will be described. If both ends of the two electrodes of each LED 3 ₁ to 3 ₃ to apply a forward bias voltage, the LED 3 ₁ to 3 ₃ are the same, the white light, red light, blue light, green light, multi-color or respectively red light, Blue light and green light are emitted separately. Accordingly, the light emitted from the LED 3 _1, as an incident light 4 _1, Without being reflected by the antireflection film _81, is incident on the rectangular prism 5 ₁ toward drawing y- direction from figure y + direction . Rectangular prism 5 part of the incident light 4 ₁ incident on the ₁ reaches the perpendicular surface 5 _1a, after being totally reflected in the figure x + direction by the reflecting film _61, reaching to the anti-reflection film at a right angle surface 5 _1b The light is emitted from the right-angle prism 5 ₁ in the x + direction in the figure without being reflected by 7 ₁ . On the other hand, the rectangular prism 5 other part of the incident light 4 ₁ incident on the _1, without being reflected directly reach the perpendicular surface 5 _1b antireflection film _71, in the drawing from the right-angle prism 5 ₁ y- direction To exit.

Next, a portion from the rectangular prism 5 ₁ in the figure x + direction emitted the incident light 4 _1, Without being reflected by the reflective film 6 _3, toward the figure x + direction from the drawing x- direction perpendicular It enters the prism 5 _4. Rectangular prism 5 ₄ part from Zuchu x- direction of the incident light 4 ₁ incident toward drawing x + direction reaches the inclined surface 5 _4c, Without being reflected by the antireflection film 8 _4, in FIG. the x- direction toward drawing x + direction emitted from the rectangular prism 5 _4. Meanwhile, some of the rectangular prism 5 ₁ in other drawing y- direction emitted the incident light 4 _1, without being reflected by the reflective film 6 _3, toward the drawing y- direction from figure y + direction Te enters the right-angle prism 5 _4. Rectangular prism 5 ₄ Zuchu y + direction from the other part of the incident light 4 ₁ incident toward figure y- direction, reaches the perpendicular plane 5 _4b, all in the figure x + direction by the reflection film 6 ₄ after being reflected, without being reflected by the reflection preventing film 8 ₄ reaches the inclined surface 5 _4c, emitted from the rectangular prism 5 ₄ toward drawing x + direction from the drawing x- direction.

Moreover, LED 3 light emitted from the _two, as the incident light 4 _2, Without being reflected by the antireflection film _82, is incident on the rectangular prism 5 ₂ toward drawing x + direction from the drawing x- direction. Some of the incident light 4 ₂ incident on the rectangular prism 5 _2, without being reflected directly reach the perpendicular plane 5 _2a antireflection film 7 _2, emitted from the rectangular prism 5 ₂ in the figure x + direction. On the other hand, the other part is the incident light 4 ₂ incident on the rectangular prism 5 _2, without being reflected directly reach the perpendicular plane 5 _2b antireflection film 7 _3, in the figure x + direction from the right-angle prism 5 ₂ Exit.

Next, a portion from the right-angle prism 5 ₂ in the figure x + direction emitted the incident light 4 _2, Without being reflected by the reflective film 6 _2, toward the figure x + direction from the drawing x- direction perpendicular It enters the prism 5 _3. Some of Zuchu x- direction of the incident light 4 ₂ incident toward drawing x + direction at a right angle prism 5 ₃ from the right-angle prism 5 _2, and reaches the perpendicular plane 5 _3a, is reflected by the reflection preventing film 7 ₄ without Rukoto, emitted from the rectangular prism 5 ₃ toward drawing x + direction from the drawing x- direction. Meanwhile, some of the right-angle prism 5 ₂ in other drawing x + direction emitted the incident light 4 _2, Without being reflected by the reflecting film _61, toward the figure x + direction from the figure the x- It enters the rectangular prism 5 _1. Rectangular prism 5 another part of the incident light 4 ₂ incident toward ₂ from the right-angle prism 5 ₁ from Zuchu x- direction to the drawing x + direction, reaches the perpendicular surface 5 _1b, anti-reflection film 7 ₁ reflecting without being, emitted from the rectangular prism 5 ₁ toward drawing x + direction from the drawing x- direction.

Next, a portion from the rectangular prism 5 ₃ in the figure x + direction emitted the incident light 4 _2, Without being reflected by the reflective film 6 _4, toward the figure x + direction from the drawing x- direction perpendicular It enters the prism 5 _4. Rectangular prism 5 in part from Zuchu x- direction at a right angle prism 5 _{4 3} of the incident light 4 ₂ incident toward drawing x + direction, to reach the inclined surface 5 _4c, is reflected by the antireflection film 8 ₄ it without exiting from the rectangular prism 5 ₄ toward drawing x + direction from the drawing x- direction. Meanwhile, some Figures in x- direction other incident light 4 ₂ emitted in the figure x + direction from the right-angle prism 5 _1, drawing from Zuchu x- direction from right-angle prism 5 ₁ at a right angle prism 5 ₄ Incident in the x + direction. Some of Zuchu x- direction of the incident light 4 ₂ incident toward drawing x + direction at a right angle prism ₄ from right-angle prism 5 _1, reaches the inclined surface 5 _4c, is reflected by the antireflection film 8 ₄ it without exiting from the rectangular prism 5 ₄ toward drawing x + direction from the drawing x- direction.

Further, the light emitted from the LED 3 _3, as an incident light 4 _3, Without being reflected by the anti-reflection film 8 _3, incident on the rectangular prism 5 ₃ toward figure y + direction from the drawing y- direction. Some of the incident light 4 ₃ incident on the rectangular prism 5 _3, reaches the perpendicular plane 5 _3b, after being totally reflected in the figure x + direction by the reflecting film 6 _2, reached the anti-reflection film at a right angle surface 5 _3a 7 without being reflected by _4, is emitted from the rectangular prism 5 ₃ in the figure x + direction. On the other hand, another part of the incident light 4 ₃ incident on the rectangular prism 5 _3, without being reflected directly reach the perpendicular plane 5 _3a antireflection film 7 _4, in the figure y + direction from the rectangular prism 5 ₃ Exit.

Next, a part of the incident light 4 ₃ emitted from the right-angle prism 5 ₃ in the x + direction in the figure is not reflected by the reflection film 6 ₄ , but is perpendicular to the x + direction in the figure from the x− direction. It enters the prism 5 _4. Some of the right-angle prism ₄ to Zuchu x- incident light 4 ₃ incident toward the direction to the drawing in x + direction, to reach the inclined surface 5 _4c, Without being reflected by the antireflection film 8 _4, in FIG. the x- direction toward drawing x + direction emitted from the rectangular prism 5 _4. On the other hand, another part of the incident light 4 ₃ emitted from the right-angle prism 5 ₃ in the y + direction in the figure is not reflected by the reflective film 6 ₄ , and is directed from the y− direction in the figure to the y + direction in the figure. incident on the rectangular prism 5 _4. Rectangular prism 5 ₄ Zuchu y- some direction from the other incident light 4 ₃ incident toward figure y + direction, and reaches the perpendicular plane 5 _4a, all in the figure x + direction by the reflecting film 6 ₃ after being reflected, without being reflected by the reflection preventing film 8 ₄ reaches the inclined surface 5 _4c, emitted from the rectangular prism 5 ₄ toward drawing x + direction from the drawing x- direction. Thus the operation described, the incident light ₄₁ to ₃ are combined by the dichroic prism 2, will be emitted as combined light 4 ₄ having a light intensity which is the sum of light quantity of the incident light ₄₁ to _3.

As described above, the light source device 1 according to the first embodiment of the present invention includes the LEDs 3 _{1 to} 3 ₃ , which are one of the point light sources that emit incident light 4 ₁ to 4 ₃ each having a predetermined light amount, and the LED _{3 1.} ˜3 ₃ , each incident light 4 ₁ ˜4 ₃ incident from the inclined surfaces 5 _1c , 5 _2c , 5 _3c (light incident surface) provided corresponding to ˜3 ₃ is combined into one combined light 4 ₄ to form one inclined surface. And a dichroic prism 2 that is one of the light combining units that emit from the light emitting surface 5 _4c (light emitting surface). Therefore, a sufficient amount of light (high luminous intensity) can be secured with low cost, small size, and low power consumption. Moreover, since the incident lights 4 ₁ to 4 ₃ incident on the dichroic prism 2 are supplied from the LEDs 3 _{1 to} 3 ₃ which are one of the point light sources, the combined light 4 ₄ becomes a parallel light flux with respect to the optical axis, It has a uniform brightness. Further, since the optical axis of the dichroic prism is fixed, there is an advantage that the dichroic prism is easy to assemble even if the accuracy when assembling the light source device and the display device described later is somewhat low.

Embodiment 2. FIG.
FIG. 3 is a schematic diagram showing the configuration of the light source device 11 according to the second embodiment of the present invention.
The light source device 11 in this example includes a beam splitter 12 and LEDs 13 ₁ and 13 ₂ . The beam splitter 12 is a cube type, and as shown in FIG. 4, the inclined surfaces of _two right-angle prisms 15 ₁ and 15 ₂ having the same shape and the same dimensions are bonded to each other. Right-angle prism 15 _1, the slope 15 _1c reflective film 16 is formed on its antireflection perpendicular surfaces 15 _1a and 15 _1b film 17 ₁ and 17 ₂ are formed. The reflective film 16 is formed to totally reflect incident light from the y + direction in the figure in the x + direction in the figure. Antireflection film 17 ₁ is formed in order to prevent the incident light from the drawing y + direction is reflected to figure y + direction. Antireflection film 17 ₂ is formed in order to prevent the light from drawing in x- direction is reflected to figure x- direction. The material of the reflection film and the antireflection film and the manufacturing method thereof are the same as those described in the first embodiment, and thus the description thereof is omitted.

The right-angle prism 15 ₂ has an anti-reflection film 17 ₃ formed on the right-angle surface 15 _2b and an anti-reflection film 17 ₄ formed on the slope 15 _2c , but nothing is formed on the right-angle surface 15 _2a. Absent. Antireflection film 17 ₃ is formed in order to prevent the incident light from the drawing x- direction is reflected to figure x- direction. Antireflection film 17 ₄ is formed in order to prevent the incident light from the drawing x- direction is reflected to figure y- direction and x- direction.

The LEDs 13 ₁ and 13 ₂ emit light of the same color, such as white light, red light, blue light, green light, or multicolor, or separately emit red light, blue light, and green light, respectively. In addition, each of the above-described reflection films is formed so that incident light having a corresponding wavelength can be reflected according to the wavelength of the incident light, and each of the above-described antireflection films has a corresponding wavelength depending on the wavelength of the incident light. It goes without saying that the incident light is prevented from being reflected. The LED _{13 1} is disposed such that the chip surface thereof is parallel to the right-angled surface 15 _1a of the right-angle prism 15 ₁ and faces the center of the inclined surface 15 _1c of the right-angle prism 15 ₁ . LED 13 _2, the chip surface at a right angle prism 15 parallel to the _second perpendicular surface 15 _2b, and are arranged so as to face the center of the right-angle prism 15 _second slope 15 _2c. That is, the LEDs 13 ₁ and 13 ₂ are arranged on the optical axis.

Next, the operation of the light source device 11 having the above configuration will be described. If both ends of the two electrodes of each LED 13 ₁ and 13 ₂ for applying a forward bias voltage, the LED 13 ₁ and 13 ₂ are identical, white light, red light, blue light, green light, multi-color or respectively red light, Blue light and green light are emitted separately. Accordingly, the light emitted from the LED 13 _1, as the incident light 14 _1, Without being reflected by the antireflection film 17 _1, incident on the rectangular prism 15 ₁ toward the figure y- direction from figure y + direction . Right-angle prism 15 portion of the incident light 14 ₁ incident on the _1, slope 15 reaches the _1c, reflection is totally reflected in the figure x + direction film 16, perpendicular surface 15 reaches the _1b antireflection film 17 ₂ in without being reflected and emitted in the figure x + direction from the right-angle prism 15 _1.

Moreover, LED 13 is light emitted from the _two, as the incident light 14 _2, without being reflected by the reflection prevention film 17 _3, incident on the rectangular prism 15 ₂ toward the figure x + direction from the drawing x- direction. Incident light 14 ₂ incident on the right-angle prism 15 ₂ reaches the inclined surface 15 _2c and is output from the right-angle prism 15 ₂ in the x + direction without being reflected by the antireflection film 17 ₄ . Next, the incident light 14 ₂ emitted from the right-angle prism 15 ₂ in the x + direction in the figure is not reflected by the reflection film 16, and enters the right-angle prism 15 ₁ from the x− direction in the figure toward the x + direction in the figure. Incident. Incident light 14 ₂ incident from the right-angle prism 15 ₂ to the right-angle prism 15 ₁ from the x-direction in the figure to the x + direction in the figure reaches the right-angle plane 15 _1b and is not reflected by the antireflection film 17 _2. , it is emitted from the rectangular prism 15 ₁ toward the figure x + direction from the drawing x- direction. Through the operation described above, the incident lights 14 ₁ and 14 ₂ are combined by the beam splitter 12 and are emitted as combined light 14 ₃ having a total light quantity of the incident lights 14 ₁ and 14 ₂ .

As described above, the light source device 11 according to the second embodiment of the present invention includes the LEDs 13 ₁ and 13 ₂ that are one of point light sources that emit incident light 14 ₁ and 14 ₂ having a predetermined light amount, and the LED 13 ₁ , respectively. And 13 ₂ , the incident light 14 ₁ and 14 ₂ incident from the right-angle surfaces 15 _1a and 15 _2b (light incident surfaces) provided corresponding to the _two light-waves are combined into one combined light 14 ₃ to form one right-angle surface 15. _1b (a light exit surface) and a beam splitter 12 that is one of the light combining sections. Therefore, substantially the same effect as that of the first embodiment described above can be obtained.

Embodiment 3 FIG.
FIG. 5 is a schematic diagram showing the configuration of the light source device 21 according to Embodiment 3 of the present invention. In FIG. 5, parts corresponding to those in FIG. 1 are given the same reference numerals, and explanation thereof is omitted. In the light source device 21 shown in FIG. 5, the three dichroic prisms 2 having the same shape and the same function are arranged on the slope 5 _4c (light emitting surface) of the front dichroic prism 2 and the slope 5 _2c of the rear dichroic prism 2. They are arranged sequentially with the (light incident surface) in contact with each other. The light source in the device 21, and one LED3 _2, and three LED3 ₁ for emitting light of the same color and the same amount of light, three LED3 for emitting light of the same color and the same amount of light as shown in FIG. 5 ₃ is provided.

Each LED 3 _1, the chip surface is rectangular prism 5 ₁ slope 5 _1c and without parallel constituting the corresponding dichroic prism 2, respectively, and the line of intersection of the right-angle prism 5 ₁ perpendicular face 5 _1a and 5 _1b It is arranged to face the midpoint. LED 3 _2, the chip surface forms a parallel to the dichroic slope 5 ₂ clauses rectangular prisms constituting the prism 2 5 ₂ positioned at the left end in FIG. 5, and, of the right-angle prism 5 ₂ perpendicular surface 5 _2a and 5 _2b It is arranged to face the midpoint of the intersection line. Each LED _{3 3} has its chip surface parallel to the inclined surface 5 _3c of the right-angle prism 5 ₃ constituting the corresponding dichroic prism 2, and the intersection of the right-angle surfaces 5 _3a and 5 _3b of the right-angle prism 5 ₃ . It is arranged to face the midpoint. That is, the LEDs 3 _{1 to} 3 ₃ are arranged on the optical axis.
The operation of the light source device 21 configured as described above is the same as that described in the first embodiment except that the operation in the dichroic prism 2 described with reference to FIG. 2 is sequentially performed in the three dichroic prisms 2. Since it is substantially the same as Embodiment 1, the description is omitted. That is, three incident light 4 ₁ , one incident light 4 ₂ , and three incident light 4 ₃ are combined by three dichroic prisms 2, and the amount of each incident light 4 ₁ to 4 ₃ is obtained. It will be emitted as combined light 4 ₅ having a total light quantity.

Thus, in the light source device 21 according to the third embodiment of the present invention, the three dichroic prisms 2 are arranged on the inclined surface 5 _4c (light emitting surface) of the preceding dichroic prism 2 and the inclined surface 5 of the _subsequent dichroic prism 2. _2c (light incident surface) are placed in contact with each other. Therefore, it is possible to provide illumination with higher and uniform luminance than that of the first embodiment with a simple and inexpensive configuration.
Furthermore, in the light source device 21 according to the third embodiment of the present invention, the combination of the three dichroic prisms 2 has been described. However, if the combination of two or more dichroic prisms 2 is used, the light enhancement effect is the number of combinations. Obtained accordingly.

Embodiment 4 FIG.
FIG. 6 is a schematic diagram showing a configuration of a light source device 31 according to Embodiment 4 of the present invention. In FIG. 6, parts corresponding to those in FIG. In the light source device 31 shown in FIG. 6, three beam splitters 12 having the same shape and the same function are arranged on a right angle surface 15 _1b (light emission surface) of the preceding beam splitter 12 and a right angle surface of the subsequent beam splitter 12. 15 _2b (light incident surface) are sequentially arranged in contact with each other. Further, the light source device 31 shown in FIG. 6, and one LED 13 _2, 3 pieces of LED 13 ₁ and is provided for emitting light of the same color and the same amount of light.

Each LED _{13 1} is arranged so that its chip surface is parallel to the right-angle surface 15 _1a of the right-angle prism 15 ₁ constituting the corresponding beam splitter 12 and faces the center of the inclined surface 15 _1c of the right-angle prism 15 _1. Has been. LED 13 _2, the chip surface at a right angle prism 15 parallel to the _second perpendicular surface 15 _2b, and are arranged so as to face the center of the right-angle prism 15 _second slope 15 _2c. That is, the LEDs 13 ₁ and 13 ₂ are arranged on the optical axis.
The operation of the light source device 31 having the above-described configuration is the same as that in the second embodiment described above except that the operation in the beam splitter 12 described with reference to FIG. 4 is sequentially performed in the three beam splitters 12. Since it is substantially the same as Embodiment 2, the description is omitted. That is, the three incident lights 14 ₁ and the one incident light 14 ₂ are combined by the three beam splitters 12, and the combined light 14 ₄ having a total light quantity of the incident lights 14 ₁ and 14 _2. Will be emitted.

As described above, in the light source device 31 according to the fourth embodiment of the present invention, the three beam splitters 12 are perpendicular to the right angle surface 15 _1b (light emission surface) of the front beam splitter 12 and the right angle of the rear beam splitter 12. The surfaces 15 _2b (light incident surfaces) are sequentially arranged in contact with each other. Therefore, it is possible to provide illumination with higher and uniform brightness than that of the above-described second embodiment with a simple and inexpensive configuration.
Furthermore, in the light source device 31 according to the fourth embodiment of the present invention, the combination of the three beam splitters 12 has been described. However, if the combination of two or more beam splitters 12 is used, the light enhancement effect is the number of combinations. Obtained accordingly.

Embodiment 5 FIG.
In each of the above-described embodiments, the example in which the light emitted from the LED is directly incident on the dichroic prism 2 or the beam splitter 12 has been described. However, the present invention is not limited to this. For example, a convex lens is interposed between the LED and each light incident surface of the dichroic prism 2 or the beam splitter 12, or a convex lens is disposed between the light exit surface from which the combined light of the dichroic prism 2 or the beam splitter 12 is emitted. It may be inserted. Alternatively, as shown in FIGS. 7 to 10, convex lenses 42 _{1 to} 42 ₃ , 52 ₁ and 52 ₂ , 62 _{1 to} 62 ₃ , between the LEDs and the respective light incident surfaces of the dichroic prism 2 or the beam splitter 12. The convex lenses 42 ₄ , 52 ₃ , 62 ₄ , and 72 ₃ may be interposed between the light emitting surfaces from which the combined light of the dichroic prism 2 or the beam splitter 12 is emitted, as well as 72 ₁ and 72 _2. . 7-10, the same code | symbol is attached | subjected to the part corresponding to each part of corresponding FIG.1, FIG.3, FIG.5, FIG.6, and the description is abbreviate | omitted. According to the fifth embodiment, the same effects as in the first to fourth embodiments described above can be obtained, and the light emitted from the LED is converted into a parallel light flux by the convex lens, thereby providing illumination with a more uniform luminance. be able to.

Embodiment 6 FIG.
FIG. 11 is a schematic diagram showing a configuration of a display device according to Embodiment 6 of the present invention.
The display device of this example is a projection type projector, and includes light source devices 1 _R , 1 _G , 1 _B , liquid crystal light valves 81 to 83, a dichroic prism 84, a projection lens 85, and a projection screen 86. Has been. The light source device 1 _R is the light source device 1 according to the first embodiment shown in FIG. 1, and the LEDs 3 _{1 to} 3 ₃ all emit red light. Similarly, the light source device 1 _G is the light source device 1 and the LEDs 3 _{1 to} 3 ₃ all emit green light, and the light source device 1 _B is the light source device 1 and the LEDs 3 _{1 to} 3 ₃ all emit blue light. It emits light.

The liquid crystal light valve 81 modulates red light supplied from the light source device 1 _R based on an R (red) signal supplied from the outside, and adds video information corresponding to the red light. Similarly, the liquid crystal light valve 82 modulates green light supplied from the light source device 1 _G based on a G (green) signal supplied from the outside, and adds video information corresponding to the green light. The liquid crystal light valve 83 modulates the blue light supplied from the light source device 1 _B based on the B (blue) signal supplied from the outside, and adds video information corresponding to the blue light.

Similar to the dichroic prism 2 shown in FIG. 2, the dichroic prism 84 is configured by bonding the right-angle surfaces of _four right-angle prisms 5 _{1 to} 5 ₄ having the same shape and the same dimensions. However, right-angle prism 5 _1, the reflective film ₆₁ for reflecting the red light is formed on the perpendicular surface 5 _1a. Right-angle prism 5 _2, to both the reflective film of the perpendicular surface 5 _2a and 5 _2b are not formed. Rectangular prism 5 _3, reflective layer 6 ₂ for reflecting blue light in the plane perpendicular 5 _3b is formed. Rectangular prism 5 _4, the perpendicular surface 5 _4a reflective film 6 ₃ for reflecting blue light are formed, the reflection film 6 ₄ is formed for reflecting the red light on the plane perpendicular 5 _4b. The dichroic prism 84 combines red light, green light, and blue light emitted from the liquid crystal light valves 81 to 83 and emits the light in the direction of the projection lens 85. For the detailed configuration, function, and manufacturing method of the dichroic prism 84, refer to, for example, Japanese Patent Application Laid-Open No. 2003-13925. It is also possible to form an appropriate antireflection film on a surface that is not the color reflection films of the rectangular prism 5 ₁ to 5 ₄ are formed. The projection lens 85 focuses the light synthesized by the dichroic prism 84 on the projection screen 86. The operation of the display device having the above-described configuration is the same as that of the prior art except that the light source devices 1 _R , 1 _G , and 1 _B are used as the light source device, and thus the description thereof is omitted. As described above, in the display device according to the sixth embodiment of the present invention, the light source devices 1 _R , 1 _G and 1 _B are used as the light source devices. High-quality video with no unevenness can be displayed. For this reason, the commercial value of the display device is improved.

Embodiment 7 FIG.
FIG. 12 is a schematic diagram showing a configuration of a display device according to Embodiment 7 of the present invention. 12, parts corresponding to those in FIG. 11 are given the same reference numerals, and explanation thereof is omitted. In the display device shown in FIG. 12, light source devices 21 _R , 21 _G and 21 _B are newly provided in place of the light source devices 1 _R , 1 _G and 1 _B shown in FIG. The light source device 21 _R is the light source device 21 according to the third embodiment shown in FIG. 5, and the LEDs 3 _{1 to} 3 ₃ all emit red light. Similarly, the light source device 21 _G is LED 3 ₁ to 3 ₃ are the above light source device 21 emits light all green light, the light source device 21 _B is the above light source apparatus 21 LED 3 ₁ to 3 ₃ are all blue light It emits light. The operation of the display device having the above-described configuration is the same as that of the prior art except that the light source devices 21 _R , 21 _G , and 21 _B are used as the light source device, and thus the description thereof is omitted. Thus, in the display device according to the seventh embodiment of the present invention, since the light source devices 21 _R , 21 _G , and 21 _B are used as the light source devices, the quality is much higher than that of the above-described sixth embodiment. Video can be displayed.

The embodiment has been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiment, and there are design changes and the like without departing from the scope of the invention. Are also included in the present invention.
For example, in each of the above-described embodiments, the example in which the antireflection film is formed on the surface of the dichroic prism 2 and the right-angle prism constituting the beam splitter 12 on which the reflection film is not formed has been described. Part or all of the film may not be formed.
Further, in the above-described Embodiments 2, 4, and 5, the example in which the beam splitter 12 is a cube type is shown, but the present invention is not limited to this, and a plate type may be used.
In each of the above-described embodiments, an example in which an LED is used as a point light source has been described. However, the present invention is not limited to this, and the point light source is a laser diode, an electroluminescence (EL) element, a fluorescent display tube (VFD). : Vacuum Fluoresent Display (especially, a field emission display (FED) which is a kind thereof) may be used. In photosynthesis using these devices, it is easier to synthesize if the wavelength of each device is shifted by the reflection film wavelength possible resolution at each synthesis location.

In the above-described third, fourth, fifth, and seventh embodiments, the example in which the number of dichroic prisms 2 or beam splitters 12 is three has been described. However, the present invention is not limited to this, and the dichroic prism 2 or beam splitter 12 is not limited thereto. The number may be 2, 4, 5, or 6 or more. In this case, it goes without saying that the number of LEDs needs to be increased as the number of dichroic prisms 2 or beam splitters 12 increases.
In the above-described sixth and seventh embodiments, the display device has three liquid crystal light valves 81 to 83. However, the present invention is not limited to this, and the display device has one liquid crystal light valve. Or it may have four or more liquid crystal light valves. In the former case, the combined light emitted from the light source device is white light, and in the latter case, the combined light emitted from the light source device is light of one color in addition to red light, green light, and blue light.
Further, in the above-described sixth and seventh embodiments, the example in which the liquid crystal light valve is used as the light modulation unit has been described. However, the present invention is not limited to this, and a mirror device type light valve may be used.

In addition, each of the above-described embodiments can divert each other's technology as long as there is no particular contradiction or problem in its purpose and configuration. For example, in the above-described sixth embodiment, instead of the light source devices 1 _R , 1 _G , 1 _B , the light source devices 11 _R , 11 _G , 11 _B , the light source devices 31 _R , 31 _G , 31 _B , the light source device 41 _R , 41 _G , 41 _B , light source devices 51 _R , 51 _G , 51 _B , light source devices 61 _R , 61 _G , 61 _B , and light source devices 71 _R , 71 _G , 71 _B may be provided. The subscripts R, G, and B of each light source device indicate that the combined light from each light source device is red light, green light, and blue light. In the third, fourth, fifth, and seventh embodiments described above, an example in which a plurality of dichroic prisms 2 or a plurality of beam splitters 12 are arranged in series has been described. However, the present invention is not limited to this. The dichroic prism 2 and the plurality of beam splitters 12 may be appropriately combined and arranged in series.

It is the schematic which shows the structure of the light source device which is Embodiment 1 of this invention. It is an exploded plan view showing a configuration of a dichroic prism. It is the schematic which shows the structure of the light source device which is Embodiment 2 of this invention. It is a disassembled plan view which shows the structure of a beam splitter. It is the schematic which shows the structure of the light source device which is Embodiment 3 of this invention. It is the schematic which shows the structure of the light source device which is Embodiment 4 of this invention. It is the schematic which shows the 1st structure of the light source device which is Embodiment 5 of this invention. It is the schematic which shows the 2nd structure of the light source device which is Embodiment 5 of this invention. It is the schematic which shows the 3rd structure of the light source device which is Embodiment 5 of this invention. It is the schematic which shows the 4th structure of the light source device which is Embodiment 5 of this invention. It is the schematic which shows the structure of the display apparatus which is Embodiment 6 of this invention. It is the schematic which shows the structure of the display apparatus which is Embodiment 7 of this invention.

Explanation of symbols

1, 1 _R , 1 _G , 1 _B , 11, 11 _R , 11 _G , 11 _B , 21, 21 _R , 21 _G , 21 _B , 31, 31 _R , 31 _G , 31 _B , 41, 41 _R , 41 _G , 41 _B , 51, 51 _R , 51 _G , 51 _B , 61, 61 _R , 61 _G , 61 _B , 71, 71 _R , 71 _G , 71 _B light source device, 2 dichroic prism (light combiner), 3 _{1 -3 3} , 13 ₁ , 13 ₂ LED, 4 ₁ -4 ₃ , 14 ₁ , 14 ₂ incident light, 4 ₄ -4 ₇ , 14 ₃ -14 ₆ combined light, 5 ₁ -5 ₄ , 15 ₁ , 15 ₂ Right angle prism, 5 _1a , 5 _1b , 5 _2a , 5 _2b , 5 _3a , 5 _3b , 5 _4a , 5 _4b , 15 _1a , 15 _1b , 15 _2a , 15 _2b Right angle surface, 5 _1c , 5 _2c , _53c , 5 _4c, 15 _1c, 15 _2c slopes ₆₁ through _4, 16 reflective film 7 _{1-7 4,} 8 _{1-8 4,} 17 ₁ to 17 ₄ antireflection film, 12 a beam splitter (light combining unit) 42 _{1-42 4} 52 _{1-52 3} 62 _{1-62 4} 72 _{1-72 3-convex} lens, 81 - 83 liquid crystal light valve (optical converter) 84 dichroic prism, 85 projection lens, 86 projection screen.

Claims (5)

A plurality of point light sources each emitting a predetermined luminous flux;
A light combining unit configured to combine the light beams incident from a plurality of light incident surfaces provided corresponding to the point light sources into one light beam and emit the light from one light output surface. Light source device.   2. The light source device according to claim 1, wherein the point light source is any one of a light emitting diode, a laser diode, an electroluminescence element, and a field electron emission display.   The light source device according to claim 1, wherein the light combining unit includes a light combining unit of a dichroic prism or a beam splitter, or a combination of the light combining units.   4. The light source device according to claim 3, wherein the light combining unit is configured such that the light incident surface of the light combining unit in the subsequent stage is opposed to the light emitting surface of the light combining unit in the previous stage. A light source device according to any one of claims 1 to 4,
An optical conversion element that modulates a light beam from the light source device based on a video signal.

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