JP2008058611A - Illumination optical system and projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain the higher luminance of a projected image simultaneously with the miniaturization/low power consumption of a projection type display device. <P>SOLUTION: The illumination optical system used for the projection type display device has: a light source lamp 40; a color separation optical system 80 separating a light beam emitted from the light source lamp 40 to respective color light beams of R, G and B; auxiliary light sources 90R, 90G and 90B emitting the light beam of any color out of R, G and B; and light compounding mirrors 100R, 100G and 100B compounding the respective color light beams separated by the color separation optical system 80 with the respective color light beams emitted from the auxiliary light sources 90R, 90G and 90B. The auxiliary light sources 90R, 90G and 90B are constituted so that their power consumption may be lower than that of the light source lamp 40 and they may have smaller size than the light source lamp 40. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  One aspect of the present invention relates to an illumination optical system that separates light emitted from a light source into a plurality of color lights and illuminates an illumination target with the separated color lights.

  Another aspect of the present invention relates to a projection display device that forms an image by modulating color light emitted from an illumination optical system based on an image signal, and enlarges and projects the formed image on a screen or the like. .

  Currently, the market of projection display devices is expanding, centering on projectors using liquid crystal panels as light valves (image forming elements). Such a projection display device modulates light emitted from an illumination optical system based on an image signal to form an image (image light), and projects (projects) the formed image (image light) onto a screen or the like. . FIG. 4 is a schematic diagram showing a schematic structure of a general projection display device 100. The projection display device 200 shown in the figure includes an illumination optical system 201, a plurality of liquid crystal panel units 202R, 202G, and 202b, and a cross dichroic prism that combines light emitted from the liquid crystal panel units 202R, 202G, and 202b ( (Hereinafter referred to as “prism” or “XDP”) 203 and a projection lens 204 that projects image light combined by the prism 203 onto a screen (not shown) or the like.

  The illumination optical system 201 includes a light source lamp 210, a blue reflecting dichroic mirror 211B, a green reflecting dichroic mirror 211G, and reflecting mirrors 212, 213, and 214. The light emitted from the light source lamp 210 first enters the blue reflecting dichroic mirror 211B. Of the light incident on the blue reflecting dichroic mirror 211B, the blue light is reflected by the mirror 211B, then the traveling direction is changed (deflected) by the reflecting mirror 212, and is incident on the liquid crystal panel unit 202B.

  On the other hand, of the green light and red light transmitted through the blue reflecting dichroic mirror 211B, the green light is reflected by the green reflecting dichroic mirror 211G and enters the liquid crystal panel unit 202G.

  The red light transmitted through the green reflecting dichroic mirror 211G is deflected by the reflecting mirror 213, then deflected again by the reflecting mirror 214, and enters the liquid crystal panel unit 202R.

The liquid crystal panel units 202R, 202G, and 202B illuminated by the respective color lights as described above modulate the incident light based on the image signal to form image lights of the respective colors. The formed image light of each color is incident on the prism 203 from a predetermined incident surface of the prism 203 and is combined into full color image light. Full-color image light exits from a predetermined exit surface of the prism 203 and enters the projection lens 204. The projection lens 204 projects the incident image light toward a screen (not shown) or the like. As described above, the enlarged image is projected on the screen. More detailed contents of the illumination optical system used in the conventional projection display device are described in Patent Document 1, for example.
Japanese Patent Laid-Open No. 2001-174909 ([0004] to [0007], FIG. 7)

  In a projection display device that projects an image based on the above principle, the brightness of the projected image greatly depends on the output of the light source lamp. Therefore, in order to achieve high brightness of the projected image, it is necessary to increase the output of the light source lamp or provide two or more light source lamps. However, when the output of the light source lamp is increased, the power consumption increases or the life of the light source lamp decreases. On the other hand, when two or more light source lamps are provided, the light source unit becomes large, and the projection display device becomes large.

  The present invention has been made in view of the above problems, and an object of the present invention is to simultaneously realize high brightness of a projected image and miniaturization and low power consumption of a projection display device.

  One of the illumination optical systems of the present invention is an illumination optical system used in a projection display device, and includes a light source lamp and color separation optics for separating light emitted from the light source lamp into two or more lights having different colors. A system, a plurality of auxiliary light sources, and light combining means for combining the light emitted from the auxiliary light source with each light separated by the color separation optical system, the auxiliary light source being compared with the light source lamp It is characterized by low power consumption and small size.

  Another one of the illumination optical systems of the present invention is an illumination optical system used in a projection display device, and a light source lamp and light emitted from the light source lamp are R (red), G (green), B A color separation optical system that separates light of each color of (blue), a plurality of auxiliary light sources that emit light of any color of R (red), G (green), and B (blue), and the color separation optical system A light combining unit that combines each separated color light and each color light emitted from the auxiliary light source, wherein the auxiliary light source consumes less power and is smaller than the light source lamp; And

  In the illumination optical system of the present invention having the above configuration, the light emitted from the light source lamp and the light emitted from the auxiliary light source are combined to increase the luminance of the illumination light. Moreover, the amount of increase in power consumption due to the provision of the auxiliary light source is extremely small compared to the case where the output of the light source lamp is increased or the number of the light source lamps is increased. Furthermore, the illumination optical system is not increased in size.

  The light synthesizing unit is preferably an optical element including a reflection region that reflects incident light and a transmission region that transmits incident light. When the light synthesizing means is the optical element, either the light separated by the color separation optical system or the light emitted from the auxiliary light source is incident on the reflection area, and the other is incident on the transmission area. It is possible to realize the above-described light synthesis only by arranging the light. As the auxiliary light source, a light-emitting diode that emits light with a power of several milliwatts and that is small and light is suitable.

  A projection display device of the present invention includes the illumination optical system of the present invention, a light valve that modulates light emitted from the illumination optical system, and a projection optical system that projects light modulated by the light valve. It is characterized by that. Therefore, the light bulb is illuminated with light whose luminance is increased by combining the light emitted from the light source lamp and the light emitted from the auxiliary light source.

  According to the present invention, it is possible to simultaneously realize high brightness of a projected image and miniaturization and low power consumption of a projection display device.

  Hereinafter, an example of an embodiment of a projection display device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic plan view showing the internal structure of the projection display apparatus of this example. In the projection display device of this example, components are housed in an outer case 1 that is divided into two parts. First, the arrangement state of main components in the outer case 1 will be outlined. Here, for convenience of explanation, the internal space of the exterior case 1 shown in FIG. 1 is divided into four in the vertical and horizontal directions, the upper right area on the paper is the first area, the upper left area is the second area, and the lower left area is the third area. The lower right area is defined as the fourth area.

  A power supply unit 10 is mainly disposed in the first area of the outer case 1. On the other hand, the optical engine 20 including the illumination optical system 30 (FIG. 2) is mainly disposed in the second area to the fourth area. More specifically, the light source lamp 40 is disposed in the fourth area, and the projection lens 21 is disposed in the second area. The light emitted from the light source lamp 40 travels counterclockwise in the order of the fourth area, the third area, and the second area, and is emitted from the projection lens 21. In addition, an intake port (not shown) and an intake fan (sirocco fans 22 and 23) for taking outside air from the intake port are arranged in the second and third areas, respectively, and an exhaust port ( (Not shown) and an exhaust fan (axial fan 24) for exhausting the air in the outer case 1 to the outside are arranged. The outside air introduced from each intake port by the intake fans 22 and 23 cools a predetermined object to be cooled while passing through a predetermined path in the exterior case 1, and is then exhausted from the exhaust port to the outside by the exhaust fan 24. The However, here is only an outline of the main components arranged in each area, elements other than the above elements may be arranged in each area, and certain elements are arranged across multiple areas Sometimes.

  FIG. 2 is a schematic diagram of the optical engine 20 provided in the projection display device of this example. The optical engine 20 includes an illumination optical system 30, three liquid crystal panel units 50R, 50G, and 50B that are individually illuminated by the illumination optical system 30, and light modulated by the liquid crystal panel units 50R, 50G, and 50B. A cross dichroic prism (hereinafter referred to as “XDP60”) to be combined and the projection lens 21 described above are included.

  The illumination optical system 30 includes the light source lamp 40 described above, an integrator optical system 70 that equalizes the luminance distribution of the light (illumination light) emitted from the light source lamp 40, and the light emitted from the integrator optical system 70 as R And a color separation optical system 80 that separates each color light of (red), G (green), and B (blue). Furthermore, it has three auxiliary light sources 90R, 90G, and 90B that emit light having the same or substantially the same color component (hue) as each color light separated by the color separation optical system 80. In addition, light combining mirrors 100R, 100G, and 100B that combine the light emitted from the auxiliary light sources 90R, 90G, and 90B with the respective color lights separated by the color separation optical system 80, and reflection mirrors 110B and 110R for optical path conversion are included. .

  The light source lamp 40 is a high-pressure discharge lamp such as an ultra-high pressure mercury lamp, a xenon lamp, or a metal halide lamp. A reflector 41 is disposed around the light source lamp 40. The light emitted from the light source lamp 40 is reflected by the reflector 41 and enters the integrator optical system 70. The integrator optical system 70 of this example includes a pair of lens arrays 71a and 71b, a field lens 72, and a polarization conversion element 73 disposed between the lens array 71b and the field lens 72. The front lens array 71a on which the light reflected by the reflector 41 first enters splits the incident light to form a large number of secondary light source images. The rear lens array 71b and the field lens 72 superimpose a plurality of secondary light source images formed by the front lens array 71a on the liquid crystal panel. The polarization conversion element 73 unifies the polarization direction of the light incident on the field lens 72 to a predetermined direction (in this example, unifies it to S-polarized light).

  The color separation optical system 80 includes a blue reflecting dichroic mirror 81, a green reflecting dichroic mirror 82, and a reflecting mirror 83. The light emitted from the integrator optical system 70 first enters the blue reflecting dichroic mirror 81. The blue reflecting dichroic mirror 81 reflects only the blue light (blue component) out of the incident light, enters the light combining mirror 100B, and transmits the other light.

  The light transmitted through the blue reflecting dichroic mirror 81 is incident on the green reflecting dichroic mirror 82 arranged at the subsequent stage of the blue reflecting dichroic mirror 81. The green reflecting dichroic mirror 82 reflects only the green light (green component) out of the incident light, enters the light combining mirror 100G, and transmits the other light.

  The light transmitted through the green reflecting dichroic mirror 82 is incident on the reflecting mirror 83 disposed at the subsequent stage of the green reflecting dichroic mirror 82. The reflection mirror 83 reflects all of the incident light and makes it incident on the light combining mirror 100R. That is, red light (red component) is incident on the light combining mirror 100R.

  The auxiliary light source 90B disposed in the vicinity of the light combining mirror 100B is a blue light emitting diode, and emits light having the same or substantially the same color component (hue) as the blue light separated by the blue reflecting dichroic mirror 81. Then, the light emitted from the auxiliary light source 90B is incident on the light combining mirror 100B.

  Here, each of the light combining mirrors 100R, 100G, and 100B includes a reflection region that reflects the incident light and a transmission region that transmits the incident light as it is. Specifically, as shown in FIG. 3, the reflective film 102 is pasted on half of the light incident surface of the light transmitting substrate (in this example, a glass plate) 101, and nothing is stuck on the other half. Absent. Therefore, the light incident on the region (reflection region) where the reflection film 102 of each of the light combining mirrors 100R, 100G, and 100B is attached is totally reflected by the film 102. On the other hand, the light incident on the area (transmission area) where the reflection film 102 of each light combining mirror 100R, 100G, 100B is not attached passes through the mirrors 100R, 100G, 100B as it is. However, the formation method and area ratio of the reflective region and the transmissive region are not limited to the above. For example, a cold film that cuts unnecessary infrared rays may be attached to the transmission region. Further, in the light combining mirrors 100R, 100G, and 100B shown in FIG. 3, the reflection region is formed in the upper half of the light incident surface, and the transmission region is formed in the lower half. However, a reflective region may be formed in the right half or the left half of the light incident surface, and a transmissive region may be formed in the remaining half. In addition, a reflective region and a transmissive region may be formed across a diagonal line. Furthermore, the reflective area and the transmissive area need not have the same area.

  In any case, the blue light reflected by the blue reflecting dichroic mirror 81 shown in FIG. 2 enters the transmission region of the light combining mirror 100B, and the light emitted from the auxiliary light source 90B enters the reflection region of the mirror 100B. The optical path is designed to As a result, the blue light separated by the blue reflecting dichroic mirror 81 and the light emitted from the auxiliary light source 90B are combined to enhance the blue illumination light. The enhanced blue illumination light is deflected by the reflection mirror 110B and enters the liquid crystal panel unit 50B.

  The auxiliary light source 90G disposed in the vicinity of the light combining mirror 100G is a green light emitting diode, and emits light having the same or substantially the same color component (hue) as the green light separated by the green reflecting dichroic mirror 82. The green light reflected by the green reflecting dichroic mirror 82 enters the transmission region of the light combining mirror 100G, and the light emitted from the auxiliary light source 90G enters the reflection region. Therefore, the green light separated by the green reflecting dichroic mirror 82 and the light emitted from the auxiliary light source 90G are combined to enhance the green illumination light. The enhanced green illumination light is incident on the liquid crystal panel unit 50G.

  Further, the auxiliary light source 90R disposed in the vicinity of the light combining mirror 100R is a red light emitting diode, and emits light having the same or substantially the same color component (hue) as the red light reflected by the reflecting mirror 83. The red light reflected by the reflection mirror 83 enters the transmission region of the light combining mirror 100R, and the light emitted from the auxiliary light source 90R enters the reflection region. Therefore, the red light reflected by the reflection mirror 83 and the light emitted from the auxiliary light source 90R are combined to enhance the red illumination light. The enhanced red illumination light is deflected by the reflection mirror 110R and enters the liquid crystal panel unit 50R.

  Each color light (illumination light) incident on the liquid crystal panel units 50R, 50G, and 50B as described above is modulated by the respective liquid crystal panel units 50R, 50G, and 50B, and then synthesized by the XDP 60. In addition, a condensing lens and an incident-side polarizing plate are respectively arranged in front of the liquid crystal panels of the liquid crystal panel units 50R, 50G, and 50B, and each color light has the same polarization direction and is collimated. Into the corresponding liquid crystal panel. In addition, an exit-side polarizing plate is disposed at the tip of each liquid crystal panel, and light emitted from the liquid crystal panel enters the XDP 60 after the polarization direction is unified.

  As described above, in the illumination optical system 30 provided in the projection display device of this example, the light beams emitted from the light source lamp 40 and separated and the light emitted from the auxiliary light sources 90R, 90G, and 90B are combined. The Therefore, even when the output of the light source lamp 40 is set to be equal to or less than that of the prior art, the luminance of each illumination light that illuminates the liquid crystal panel units 50R, 50G, and 50B (liquid crystal panel) is Equivalent or better. Moreover, white light (white) which is these synthetic | combination light (synthesis | combination color) is also strengthened by each illumination light of R * G * B being enhanced. Further, the auxiliary light sources 90R, 90G, and 90B are light-emitting diodes that consume very little power (about several milliwatts) compared to the light source lamp (discharge lamp) 40 and are small and light. In other words, in the projection display apparatus of this example, the high brightness of the projected image and the miniaturization and low power consumption of the apparatus are achieved at the same time.

  In the present specification, an example of the embodiment of the present invention has been described taking the case where the auxiliary light source is a monochromatic light emitting diode as an example. However, the light emitting diode as the auxiliary light source may be a full color light emitting diode. Of course, the auxiliary light source may be any light source that consumes less power than the light source lamp and is small, and is of course not limited to a light emitting diode.

  In addition, the light emitted from each auxiliary light source can be incident on the transmission area of the light combining mirror, and each color light separated by the color separation optical system can be incident on the reflection area of the mirror to synthesize both lights. . In short, as long as it is possible to synthesize each color light emitted and separated from the light source lamp and the light emitted from the auxiliary light source, the synthesis means is not limited to a specific means.

  The voltage applied to the auxiliary light source can be made variable so that the light emission luminance can be adjusted. According to such a configuration, when the luminance of the light source lamp decreases for some reason, the luminance decrease of the light source lamp can be compensated by increasing the light emission luminance of the auxiliary light source.

  When the light emitted from the light source lamp is also separated into intermediate colors other than R, G, and B by the color separation optical system, an auxiliary light source that emits light of the same or substantially the same color component (hue) as that intermediate color is added You can also

  The present invention can also be applied to an illumination optical system and a projection display device that perform color separation of light emitted from a light source lamp in a time-sharing manner. For example, it is possible to use a full-color light-emitting diode as an auxiliary light source and change the light emission color in accordance with the timing of color separation by the color separation optical system.

1 is a schematic plan view showing an example of an embodiment of a projection display device of the present invention. It is a schematic diagram of the optical engine shown in FIG. It is a schematic diagram which shows the structure of the photosynthetic mirror shown in FIG. It is a schematic diagram which shows schematic structure of the conventional projection display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exterior case 10 Power supply unit 20 Optical engine 21 Projection lens 22, 23 Sirocco fan 24 Axial fan 30 Illumination optical system 40 Light source lamp 41 Reflector 50R, 50G, 50B Liquid crystal panel unit 60 Cross dichroic prism (XDP)
70 Integrator Optical System 80 Color Separation Optical System 90R, 90G, 90B Auxiliary Light Source 100R, 100G, 100B Photosynthesis mirror 101 Light transmissive substrate 102 Reflective film

Claims (5)

An illumination optical system used in a projection display device,
A light source lamp,
A color separation optical system for separating light emitted from the light source lamp into two or more lights having different colors;
A plurality of auxiliary light sources;
A light combining means for combining light emitted from the auxiliary light source with each light separated by the color separation optical system;
An illumination optical system, wherein the auxiliary light source consumes less power than the light source lamp and is small. An illumination optical system used in a projection display device,
A light source lamp,
A color separation optical system that separates light emitted from the light source lamp into R (red), G (green), and B (blue) color lights;
A plurality of auxiliary light sources emitting light of any color of R (red), G (green), and B (blue);
Light combining means for combining each color light separated by the color separation optical system and each color light emitted from the auxiliary light source;
An illumination optical system, wherein the auxiliary light source consumes less power than the light source lamp and is small.   The light synthesizing unit is an optical element including a reflection region for reflecting incident light and a transmission region for transmitting incident light, and the optical element is light separated by the color separation optical system or the auxiliary element. The illumination optical system according to claim 1 or 2, wherein any one of light emitted from a light source is incident on the reflection region and the other is incident on the transmission region.   4. The illumination optical system according to claim 1, wherein the auxiliary light source is a light emitting diode.   5. An illumination optical system according to claim 1, a light valve that modulates light emitted from the illumination optical system, and a projection optical system that projects light modulated by the light valve. A projection display device characterized by that.

Images