JP4056435B2 - Projector device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projector apparatus, and more particularly to a projector apparatus that prevents color unevenness from occurring in a color image.
[0002]
[Prior art]
Conventionally, there is a projector device using a liquid crystal panel (LCD) as a video display device. This projector apparatus has an optical system shown in the configuration diagram of FIG. As shown in FIG. 4, the projector device includes a light source 1 using an ultrahigh pressure mercury lamp and a reflecting mirror 2.
[0003]
The integrators 3a and 3b are a combination of a large number of lens elements, and have a function of making the illuminance of the illumination light beam uniform when the liquid crystal panel is irradiated by incorporating this into the illumination system. The polarization conversion unit 4 is formed of a polarization conversion element in a strip shape, and further includes a field lens 7 and condenser lenses 12R, 12G, and 12B, and has a function of effectively irradiating illumination light to the liquid crystal panels 13R, 13G, and 13B. The dichroic mirrors 6 and 7 have a role of separating colors into R, G, and B, and the cross dichroic prism 14 has a role of recombining light transmitted through the color-separated liquid crystal panels.
[0004]
The dichroic prism 14 is formed by joining four right-angle prisms, and dichroic made of a dielectric multilayer film having spectral characteristics as a red light reflecting mirror and a blue light reflecting mirror, respectively, on two perpendicular joining surfaces. It is formed by applying a film, and it is possible to combine the three primary color lights of red, green and blue into one light beam of white light. The projection lens 15 is configured to project the combined three primary color lights on a screen arranged at a predetermined distance, and to enlarge and project a full color image on the screen.
[0005]
On the other hand, a mirror 11x is disposed after the relay lens 10 in the relay optical path. The projection lens 15 enlarges and projects the image displayed on the liquid crystal panels 13R, 13G, and 13B onto the screen 16, and has a focus adjustment function for adjusting the focus of the projection image. A zoom function for changing the size of the screen without changing the projection distance may be added.
[0006]
Next, the projector operation will be described. As shown in FIG. 4, the light emitted from the light source 1 is reflected by the reflecting mirror 1a. The reflected light becomes parallel light and enters the integrator 3 via the mirror 2. The integrator 3 has a function of making the illuminance of the illumination light beam uniform when the liquid crystal panel 13 is irradiated. The polarization direction of the light transmitted through the integrator 3 is unified by the polarization conversion unit 4.
[0007]
The light transmitted through the field lens 5 is condensed onto the liquid crystal panels 13R, 13G, and 13B by the condenser lenses 12R, 12G, and 12B. Meanwhile, the white light is split into red light by the dichroic mirror 6 and the green light is split by the dichroic mirror 7. All that remains is blue light. The split red light, green light, and blue light illuminate the corresponding liquid crystal panel 13.
[0008]
The two illumination lights are finally combined on the liquid crystal panel 13. The liquid crystal panel 13 for each color displays an image in a transmissive and shielded state according to the input video signal, and is color-synthesized by the cross dichroic prism 14. The synthesized light is magnified by the projection lens 15 and forms an image on the screen 16.
[0009]
FIG. 5 is a schematic diagram showing a liquid crystal video projector according to another conventional example. By arranging an even number of relay lenses in the optical system, the upside down of the illumination light image by the relay lenses is restored. There is something like that. This liquid crystal video projector includes a light source 1b, first and second dichroic mirrors 6a and 7a for separating three primary color lights, first, second and third total reflection mirrors 8, 9, 11x, and three A liquid crystal display panel 12R (for red light), 12G (for green light), 12B (for blue light), a dichroic prism 14 that synthesizes three primary color lights, and a projection lens 15a are provided.
[0010]
The second dichroic mirror 6a is a green / red light reflecting mirror, and the first dichroic mirror 7a is a green light reflecting mirror, each having a spectral characteristic of reflecting a predetermined primary color light as a mirror on a glass substrate. A dichroic film made of a dielectric multilayer film is applied. Each of the three liquid crystal display panels 13 is composed of a twisted nematic (TN) type liquid crystal display element, displays an image in accordance with a corresponding video signal from a liquid crystal driver (not shown), and brightness-modulates each incident primary color light. . In this liquid crystal video projector, the optical members are arranged on a single plane as shown in FIG.
[0011]
In addition, two relay lenses 121 and 122 are arranged in the system for red light, and one field lens 123 and 12R is provided at the front stage of the first relay lens 121 and the rear stage of the second relay lens 122, respectively. However, two field lenses 124 and 125 are arranged between the relay lenses 121 and 122. Further, field lenses 12G and 12B are arranged between the first dichroic mirror 7a and the green light liquid crystal display panel 13G, and between the third total reflection mirror 8 and the blue light liquid crystal display panel 13B.
[0012]
The operation of the liquid crystal video projector having such a configuration will be described. The light (white light) output from the light source 1b is separated into the blue light B and the remaining primary color light by the second dichroic mirror 6a. As described above, the second dichroic mirror 6a is a dichroic mirror having a spectral characteristic that reflects the green light G and the red light R, and reflects primary color light other than the blue light B in the left-right direction with respect to the illumination light. To do. The blue light B that has passed through the second dichroic mirror 6a is reflected at right angles by the third total reflection mirror 8 and guided to the blue light liquid crystal display panel 13B.
[0013]
On the other hand, primary color light other than the blue light B, which is reflected by the second dichroic mirror 6a in the left direction at right angles, is separated into green light G and red light R by the first dichroic mirror 7a. As described above, the first dichroic mirror 7a has the spectral characteristic of reflecting the green light G, and is arranged so that the incident angle is 45 ° with respect to the primary color light other than the blue light B. Therefore, the green light G is reflected at right angles and the red light R is transmitted.
[0014]
The green light G reflected by the first dichroic mirror 7a is guided to the green light liquid crystal display panel 13G. Further, the first total reflection mirror 9 causes the red light R transmitted from the first dichroic mirror 7a to be incident at an incident angle of 45 ° and is reflected in a right angle direction, and the second total reflection mirror 11x is The red light R reflected by the first total reflection mirror 9 is incident at an incident angle of 45 °, and is reflected so as to be reflected in the direction of the liquid crystal display panel 13R for red light which is a right angle direction.
[0015]
In this way, the primary color lights R, G, B incident on the corresponding liquid crystal display panels 13R, 13G, 13B correspond to the primary color lights R, G, B in the liquid crystal display panels 13R, 13G, 13B. Then, the luminance is modulated by the image signal to be processed, and then synthesized into one by the dichroic prism 14, enlarged by the projection lens 15, and projected onto a predetermined screen 16. As a result, the images displayed on the liquid crystal display panels 13R, 13G, and 13B are projected on the screen 16 as full-color images.
[0016]
In this conventional example, two relay lenses 121 and 122 are inserted into the red light R system. That is, the light image of the light source 1b is formed once at the position between the two relay lenses 121 and 122 by the first relay lens 121, and then the red light liquid crystal display panel 13R by the second relay lens 122. It is imaged again on top. The light image of the light source 1b is once reversed vertically and horizontally by the first relay lens 121, but vertically and horizontally is reversed again by the second relay lens 122, and the original light image is vertically and horizontally disposed. Are formed on the liquid crystal display panel 13R for red light (see, for example, Patent Document 1).
[0017]
[Patent Document 1]
JP-A-10-206815 [0018]
[Problems to be solved by the invention]
In the above-described conventional example, the mirror 11x is disposed after the relay lens 10 in the relay optical path, and the mirror 11x is inserted perpendicularly to the relay optical path. The lens 10 is left and right and upside down by the lens 10, and the intensity distribution becomes different. As a result, there is a problem that color unevenness appears on the screen 15.
[0019]
Further, considering the increase in luminance in the future, it is conceivable that the F number of the illumination light will increase, and color unevenness may occur due to the influence of the incident angle dependency by the dichroic mirrors 6 and 7. The horizontal direction with respect to the optical axis can be corrected by the wedges of the dichroic mirrors 6 and 7, but correction in the vertical direction is difficult.
[0020]
Further, in another conventional example, a plurality of lenses 121 and 122 are inserted in order to reverse the illumination light again in the relay optical path, but the relay optical path becomes extremely long and the size of the optical engine becomes large. There is a problem.
[0021]
The object of the present invention is to solve these problems, prevent color unevenness from occurring in a color image, improve the non-uniform difference in illumination light that occurs when three colors are combined, and increase the size of the optical engine. It is an object of the present invention to provide a projector device that does not become necessary.
[0022]
[Means for Solving the Problems]
In the configuration of the present invention, light from a light source is decomposed into three color lights by two dichroic mirrors, each of these color lights is guided to three liquid crystal display panels, intensity modulated using an input signal, and synthesized by a dichroic prism, A projector device for enlarging and projecting the combined light, wherein the two dichroic mirrors are wedge-corrected , and include a relay optical path having a relay lens, a total reflection mirror, and a combination mirror, and the dichroic of each color light The color light transmitted through the mirror passes through the relay optical path in the order of a relay lens, a total reflection mirror, and a combination mirror , and the combination mirror includes two mirrors joined so as to be orthogonal to each other by a predetermined joint line portion. parts are arranged such that 45 ° inclined with respect to the color light incident on the combination mirror, the light source light To wherein there the Rukoto to reverse the upper and lower.
[0023]
In the present invention, the combination mirror is composed of two mirrors bonded to each other at right angles to each other , and a bonding line of the two mirrors can be inclined by 45 ° with respect to incident light , The combination mirror may be disposed after the relay lens .
[0024]
According to the configuration of the present invention, the light from the light source is color-separated into a plurality of color lights by the dichroic mirror, and then passes through the optical path of each color. In the relay optical path, the light once formed by the relay lens Although it is inverted vertically and horizontally, the vertical direction is inverted again by the combination mirror and illuminates the liquid crystal panel, so the intensity distribution of the illumination light in the relay optical path is nonuniform in the vertical direction caused by reversing the illumination light of other colors Can be improved.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration diagram showing a configuration of a projector according to an embodiment of the present invention. In the projector of this embodiment, the light source 1 is provided with a reflecting mirror 2. Here, an ultra-high pressure mercury lamp is used as the light source 1. In addition to this, a light source such as a metal halide lamp, a halogen lamp, or a xenon lamp can be used as the light source 1. The reflecting mirror 2 is a parabolic mirror.
[0026]
The integrators 3a and 3b are a combination of a large number of lens elements, and have the function of making the illuminance of the illumination light beam uniform when the liquid crystal panel 13 is irradiated by incorporating this into the illumination system. The polarization conversion unit 4 is composed of a polarization conversion element in a strip shape. Further, a field lens 7 and condenser lenses 12R, 12G, and 12B are disposed, and have a function of effectively irradiating illumination light to the liquid crystal panels 13R, 13G, and 13B. The dichroic mirrors 6 and 7 have a role of separating colors into R, G, and B, and the cross dichroic prism 14 has a role of recombining light transmitted through the color-separated liquid crystal panels 13.
[0027]
On the other hand, the combination mirror 11 is disposed after the relay lens 10 in the relay optical path. As shown in the perspective view and the side view of FIGS. 2A and 2B, the mirror 11 has a configuration in which two mirrors 11a and 11b are combined. That is, the two mirrors 11a and 11b are joined orthogonally to each other. Therefore, as shown in FIG. 2, the light incident on the upper mirror 11a is reflected by the reflection point 11c of the mirror 11a, and this reflected light is incident on the lower mirror 11b and reflected by the reflection point 11d of the mirror 11b.
Therefore, the light inverted in the direction orthogonal to the joining line of the two mirrors 11a and 11b is further inverted, and is equivalent to the case where the incident light returns as it is.
[0028]
In this case, as shown in FIG. 3A, the light incident on the lower mirror 11b is reflected by the mirror 11b, is incident on the upper mirror 11a, and the light reflected by the mirror 11a is the light incident on the mirror 11b. And emits in the opposite direction. Further, as shown in FIG. 3B, the light incident on the upper mirror 11a and reflected by the mirror 11a is incident on the lower mirror 11b, and the light reflected by the mirror 11b is the same as the light incident on the mirror 11a. The light is emitted in the reverse direction.
Therefore, in FIG. 3B, when the mirror junction line portion of the combination mirror 11 is inclined by 45 ° with respect to the incident light, light inclined by 90 ° in the inclination direction is emitted as shown in FIG. The In FIG. 1, the combination mirror 11 is used in this way.
[0029]
The projection lens 15 enlarges and projects the image displayed on the liquid crystal panels 13R, 13G, and 13B onto the screen 16, and has a focus adjustment function for adjusting the focus of the projection image. A zoom function for changing the size of the screen without changing the projection distance may be added.
[0030]
Next, the operation of this embodiment will be described. As shown in FIG. 1, the light emitted from the light source 1 is reflected by the reflecting mirror 2. The reflected light enters the integrator 3 as parallel light. The integrator 3 has a function of making the illuminance of the illumination light beam uniform when the liquid crystal panel 13 is irradiated. The polarization direction of the light transmitted through the integrator 3 is unified by the polarization conversion unit 4.
[0031]
The light transmitted through the field lens 5 is condensed onto the liquid crystal panels 13R, 13G, and 13B by the condenser lenses 12R, 12G, and 12B. Meanwhile, the white light is split into red light by the dichroic mirror 6 and the green light is split by the dichroic mirror 7.
[0032]
All that remains is blue light. Each of the dispersed red light, green light, and blue light irradiates the corresponding liquid crystal panel. The two illumination lights are finally combined on the liquid crystal panel 13. The liquid crystal panel 13 for each color displays an image in a transmissive and shielded state according to the input video signal, and is color-synthesized by the cross dichroic prism 14. The synthesized light is magnified by the projection lens 15 and forms an image on the screen 16.
[0033]
Here, in this embodiment, the relay lens 10 is inserted in the blue system. That is, the light from the light source 1 is once imaged in the vicinity of the relay lens 10 and the image is reversed left and right. Thereafter, it is inverted again by the combination mirror 11 in the vertical direction.
[0034]
As another embodiment of the present invention, in the configuration of FIG. 1, blue B is used as a relay optical path, but red R is also used as a relay optical path, and a combination mirror 11 can be similarly inserted.
[0035]
【The invention's effect】
As described above, according to the configuration of the present invention, first, the illumination light of the blue light path is aligned with the green and red illumination lights in the vertical direction, so that the illumination light that is generated when the three colors are combined is not uniform. There is an effect that the difference can be improved.
[0036]
Second, in order to reverse the illumination light again in the relay optical path, there is a method of inserting a plurality of lenses, but the relay optical path becomes extremely long and the size of the optical engine increases. In the invention, there is an effect that it is not necessary to increase the size of the optical engine only by inserting the combination mirror.
[Brief description of the drawings]
FIG. 1 is a block diagram of a projector apparatus for explaining a first embodiment of the present invention.
2A and 2B are a perspective view of a part of a combination mirror 11 used in FIG. 1 and an optical path diagram thereof.
3A and 3B are cross-sectional views illustrating the operation of the optical path of the combination mirror 11 in FIG.
FIG. 4 is a configuration diagram of a projector device of a conventional example.
FIG. 5 is a configuration diagram of another conventional projector apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Light source 1a Reflection mirror 2,8,9,11a, 11b, 11x Mirror 3a, 3b Integrator 4 Polarization conversion part 5,123-125 Field lens 6,7 Dichroic mirror 10,121,122 Relay lens 11 Combination mirror 11c, 11d Reflection points 12R, 12G, 12B Condenser lenses 13R, 13G, 13B Liquid crystal panel 14 Dichroic prism 15 Projection lens 16 Screen

Claims (1)

The light from the light source is separated into three color lights by two dichroic mirrors, each of these color lights is guided to three liquid crystal display panels, the intensity is modulated using the input signal, synthesized by the dichroic prism, and this synthesized light is enlarged and projected. A projector device,
The two dichroic mirrors are wedge-corrected,
A relay optical path having a relay lens, a total reflection mirror, and a combination mirror;
The color light transmitted through the dichroic mirror of the color light, the relay lens, the total reflection mirror, passes through the relay optical path in the order of the combined mirror,
The combination mirror includes two mirrors joined so as to be orthogonal to each other by a predetermined joining line part, and the joining line part is arranged to be inclined by 45 ° with respect to the color light incident on the combination mirror, projector apparatus wherein there the Rukoto was turned upside down and the light image of the light source.

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