JP2009204693A - Projector and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector for achieving increasing a luminance dynamic range and gray-scale levels without degrading image quality due to coloring or color irregularity, and to provide a manufacturing method thereof. <P>SOLUTION: The projector 1 includes: a light source 2; a first optical modulation element (reflection type liquid crystal light valve 5) modulating light from the light source 2; a plurality of second optical modulation elements (transmission type liquid crystal light valves 10R, 10G and 10B) respectively modulating a plurality of color light beams from the first optical modulation element; a color separating and synthesizing element (color separating and synthesizing prism 7) separating the light beam from the first optical modulation element into a plurality of color light beams and also synthesizing the color light beams modulated by the plurality of second optical modulation elements; a plurality of light transmission optical systems (mirrors 8 and 9) transmitting the respective color light beams from the color separating and synthesizing element to the respective second optical modulation elements; a projection optical system (projection lens 11) projecting an image; and a light transmission optical system positioning means positioning each of the plurality of light transmission optical systems. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector and a method for manufacturing the projector, and more particularly to a projector including a two-stage light modulation element of a first light modulation element and a second light modulation element, and a method for manufacturing the projector.

In recent years, electronic display devices such as LCD (Liquid Crystal Display), EL (Electro-Luminescence) displays, plasma displays, CRTs (Cathode Ray Tubes), and projectors have been remarkably improved. Devices with nearly comparable performance are being realized. However, regarding the luminance dynamic range, the reproduction range is about 1 to 10 ² [nit], and the number of gradations is generally 8 bits. On the other hand, human vision has a range of luminance dynamic range that can be perceived at a time of about 10 ⁻² to 10 ⁴ [nit], and the luminance discrimination capability is 0.2 [nit]. It is said to be equivalent to 12 bits. When viewing the display image of the current display device via such visual characteristics, the narrowness of the luminance dynamic range is conspicuous, and in addition, the gradation of the shadow part and highlight part is insufficient, You will feel unsatisfactory with the reality and power of the displayed image.

In CG (Computer Graphics) used in movies and games, display data (hereinafter referred to as HDR (High Dynamic Range) display data) has a luminance dynamic range and gradation characteristics close to human vision. The pursuit of reality is becoming mainstream. However, since the performance of the display device that displays it is insufficient, there is a problem that the expressive power inherent in the CG content cannot be fully exhibited.
Furthermore, in the next OS (Operating System), adoption of a 16-bit color space is planned, and the dynamic range and the number of gradations are dramatically increased as compared with the current 8-bit color space. Therefore, it is expected that the demand for realizing a high dynamic range and high gradation electronic display device capable of utilizing the 16-bit color space will increase.

  Among display devices, a projection display device (projector) such as a liquid crystal projector or a DLP (Digital Light Processing (trademark)) projector can display a large screen, and is effective in reproducing the reality and power of a display image. A display device. In this field, the following proposals have been made to solve the above problems.

  A basic configuration for expanding the luminance dynamic range in a projector is to form a desired illumination light amount distribution by modulating a light beam emitted from a light source with a first light modulation element, and this illumination light amount distribution is formed on the second light modulation element. , And further illuminates after further modulation by the second light modulation element. As the light modulation element, a transmission type light modulation element having a pixel structure or a segment structure whose light propagation characteristics can be controlled independently and capable of controlling a two-dimensional transmittance distribution is used. A typical example is a liquid crystal light valve. Further, instead of the transmission type light modulation element, a reflection type light modulation element may be used, and a representative example thereof is a DMD (Digital Micromirror Device) element.

  Consider a case where a light modulation element having a dark display transmittance of 0.2% and a bright display transmittance of 60% is used. The conventional projection display device is configured to use this light modulation element alone, and the luminance dynamic range is 60 / 0.2 = 300. On the other hand, the above display device corresponds to optically arranging two stages of light modulation elements each having a luminance dynamic range of 300 in series, and thus theoretically has a luminance of 300 × 300 = 90000. A dynamic range can be realized. The same idea holds for the number of gradations, and the number of gradations exceeding 8 bits can be obtained by optically arranging 8-bit gradation light modulation elements in series. The first light modulation element and the second light modulation element are separately driven by a first modulation signal and a second modulation signal generated from the video signal.

By the way, one liquid crystal light valve is arranged as the first light modulation element, and a plurality of second light modulation elements (liquid crystals) are arranged by a relay lens in which an image thereof is arranged between the first light modulation element and the second light modulation element. A configuration for transmitting to the incident surface of the light valve is disclosed in Patent Document 1 below. In Patent Document 1, a light separating unit that separates light modulated by the first light modulation element into a plurality of different color lights, and a light combining unit that combines light modulated by the plurality of second light modulation elements, A configuration realized by an integrated cross dichroic prism is disclosed. In this configuration, since one cross dichroic prism serves as both the light separating means and the light combining means, the entire apparatus can be reduced in size.
JP 2005-227695 A

  In the configuration of Patent Document 1, a white light beam emitted from a light source is color-separated into three primary color light beams of R, G, and B using a cross dichroic prism. However, a color shift occurs between the separated R, G, and B light beams, and the optical image of the first light modulation element cannot be accurately transmitted to the second light modulation element. As a result, there is a problem in that the display image is colored or uneven in color, resulting in image quality deterioration. Furthermore, the cross dichroic prism is formed by bonding four triangular prisms each having a dichroic film formed on a specific surface, but the bonding accuracy is generally about 10 seconds, and sufficient accuracy cannot be secured. In addition, there is a slight difference in refractive index between the four triangular prisms. There is also a problem that these lead to a cause of color misregistration in each of the R, G, and B light beams.

  The present invention has been made to solve the above-described problems, and provides a projector capable of realizing a luminance dynamic range expansion and an increase in the number of gradations without causing image quality deterioration due to coloring or color unevenness, and a method for manufacturing the projector. The purpose is to provide.

  In order to achieve the above object, a projector according to the present invention includes a light source, a first light modulation element that modulates light emitted from the light source, and light emitted from the first light modulation element depending on a wavelength range. A plurality of second light modulation elements that respectively modulate a plurality of separated color lights in different wavelength ranges; a color separation unit that separates light modulated by the first light modulation elements into the plurality of color lights; and the plurality of second light modulation elements. A color separation / combination element having a color composition unit that synthesizes the plurality of color lights modulated by the two-light modulation element; and each color light emitted from the color separation unit of the color separation / combination element A plurality of light transmission optical systems respectively transmitting to the two light modulation elements, a projection optical system for projecting an image composed of the combined light synthesized by the color combining unit of the color separation / synthesis element, and a plurality of light transmission optical systems Adjust each position And transmission optics position adjusting means, characterized by comprising a.

  According to the projector of the present invention, since the light transmission optical system position adjusting means for adjusting the position of each of the plurality of light transmission optical systems is provided, the position adjustment of the plurality of second light modulation elements is performed after the second light modulation element is adjusted. The alignment of the optical image of one light modulation element to each second light modulation element can be performed independently for each color using the light transmission optical system position adjusting means. As a result, accurate alignment and accurate luminance modulation are possible, and a projector capable of displaying an image excellent in image quality without coloring or color unevenness can be realized.

  Alternatively, another projector of the present invention includes a light source, a first light modulation element that modulates light emitted from the light source, and different wavelengths in which the light emitted from the first light modulation element is separated by a wavelength range. A plurality of second light modulation elements that respectively modulate a plurality of color lights in the region, a color separation unit that separates light modulated by the first light modulation elements into the plurality of color lights, and the plurality of second light modulation elements A color separation / combination element having a color combining unit that combines the plurality of modulated color lights, and each color light emitted from the color separation unit of the color separation / combination element to the plurality of second light modulation elements A plurality of light transmission optical systems that respectively transmit, a projection optical system that projects an image composed of synthesized light synthesized by the color synthesis unit of the color separation / synthesis element, and one light among the plurality of light transmission optical systems Other than transmission optics A light transmitting optical system position adjusting means for adjusting the position of each of the transfer optical system, characterized by comprising a position, a first optical modulation element position adjusting means for adjusting the said first optical modulation element.

  According to another projector of the present invention, light transmission optical system position adjusting means for adjusting the position of each of the other light transmission optical systems other than one light transmission optical system, and the position of the first light modulation element are adjusted. And adjusting the position of the plurality of second light modulation elements, and then aligning the optical image of the first light modulation element to each second light modulation element. Can be performed independently for each color. At this time, first, the position of the first light modulation element is aligned with respect to one second light modulation element using the first light modulation element position adjusting means for one optical path, and then the remaining light paths are The optical image of the first light modulation element is aligned with each of the remaining second light modulation elements using the light transmission optical system position adjusting means. As a result, accurate alignment and accurate luminance modulation are possible, and a projector capable of displaying an image excellent in image quality without coloring or color unevenness can be realized.

In the present invention, the plurality of color lights are red light, green light, and blue light, and the color separation / synthesis element includes a red light prism, a green light prism, and a blue light prism, and the red light The light prism reflects the red light out of the light emitted from the first light modulation element and reflects the wavelength selective reflection surface that transmits the green light and the blue light and the wavelength selective reflection surface. A total reflection surface that totally reflects the red light toward a predetermined optical path toward the second light modulation element, and the blue light prism is transmitted through the wavelength selective reflection surface of the red light prism. A wavelength selective reflection surface that reflects blue light and transmits the green light, and the blue light reflected on the wavelength selective reflection surface is totally reflected toward a predetermined optical path toward the second light modulation element. The green light prism having a total reflection surface that totally reflects the green light transmitted through the wavelength selective reflection surface of the blue light prism can be used. .
According to this configuration, since the alignment accuracy between the prisms is relaxed compared to the case where a cross dichroic prism is used, it becomes easier to adjust the imaging position of the optical image of the first light modulation element, and image quality deterioration is reduced. It can prevent more reliably.

  The projector manufacturing method according to the present invention includes a light source, a first light modulation element that modulates the light emitted from the light source, and different wavelength ranges in which the light emitted from the first light modulation element is separated by a wavelength range. A plurality of second light modulation elements that respectively modulate the plurality of color lights, a color separation unit that separates light modulated by the first light modulation elements into the plurality of color lights, and a plurality of second light modulation elements. A color separation / combination element having a color composition unit that synthesizes the plurality of color lights, and each color light emitted from the color separation unit of the color separation / combination element to each of the plurality of second light modulation elements. A projector manufacturing method comprising: a plurality of light transmission optical systems for transmitting; and a projection optical system for projecting an image composed of synthesized light synthesized by a color synthesis unit of the color separation / synthesis element, wherein the projection Paired with optical system Adjusting the position of each of the plurality of second light modulation elements, and adjusting the position of each of the plurality of light transmission optical systems to thereby adjust the position of the optical image of the first light modulation element. And a step of aligning with each of the second light modulation elements.

  Another projector manufacturing method according to the present invention includes a light source, a first light modulation element that modulates light emitted from the light source, and light emitted from the first light modulation element that is separated according to a wavelength range. A plurality of second light modulation elements that respectively modulate a plurality of color lights in a wavelength region, a color separation unit that separates light modulated by the first light modulation elements into the plurality of color lights, and the plurality of second light modulation elements A color separation / combination element that combines the plurality of color lights modulated by the color separation unit, and a plurality of second light modulation elements for outputting each color light emitted from the color separation unit of the color separation / combination element A projector manufacturing method comprising: a plurality of light transmission optical systems that respectively transmit to a projection optical system that projects an image composed of synthesized light synthesized by a color synthesis unit of the color separation / synthesis element; Projection optical system The position of each of the plurality of second light modulation elements is adjusted, and the position of the first light modulation element is adjusted to adjust the position of the optical image of the first light modulation element. Aligning with respect to one second light modulation element of the two light modulation elements, and one light transmission optical system corresponding to the one second light modulation element among the plurality of light transmission optical systems The position of the optical image of the first light modulation element is adjusted with respect to each of the other second light modulation elements other than the one second light modulation element by adjusting the position of the other light transmission optical system except for And a step of aligning.

  According to the above two projector manufacturing methods of the present invention, it is possible to realize a projector capable of displaying an image with excellent image quality without coloring or color unevenness by enabling accurate alignment and accurate brightness modulation. .

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The projector according to the present embodiment is an example of a two-modulation type liquid crystal projector that employs liquid crystal light valves for both the first light modulation element and the second light modulation element.
In this embodiment, a reflective liquid crystal light valve for luminance modulation is used as the first light modulation element in the front stage, and three transmissive liquid crystal light valves for color modulation are used as the second light modulation element in the rear stage.

FIG. 1 is a schematic configuration diagram (perspective view) of a projector according to the present embodiment. FIG. 2 is a plan view of the same. FIG. 3 is a flowchart showing a manufacturing process of the projector.
In the following drawings, the scales of dimensions and positional relationships may be different for each component in order to make each component easier to see.

  As shown in FIGS. 1 and 2, the projector 1 according to this embodiment includes a light source 2, a uniform illumination optical system 3 that uniformizes the luminance distribution of light incident from the light source 2, and a polarized beam from the uniform illumination optical system 3. A reflective liquid crystal light valve 5 for modulating the luminance of all wavelengths of light incident through a splitter 4 (Polarized Beam Splitter, hereinafter abbreviated as PBS), and reflected from the reflective liquid crystal light valve 5 by the PBS 4 A relay lens 6 that relays the emitted light, a color separation / combination prism 7 that separates light in all wavelength regions into light of three primary colors of R, G, and B, or that combines light of three primary colors of R, G, and B, and a relay Three sets of transmissive liquid crystal light valves 10R that respectively modulate the luminances of the three primary colors of R, G, and B in the wavelength region of the light emitted from the lens 6 and incident through the color separation / combination prism 7 and the mirrors 8 and 9. , 10G, 10B , Emitted from the transmission type liquid crystal light valves, the incident light are combined by the color separating and synthesizing prism 7 is schematically constituted by a projection lens 11 for projecting on a screen (not shown).

The light source 2 includes a lamp such as a high-pressure mercury lamp and a reflector that reflects light emitted from the lamp. The light beam emitted from the light source 2 enters the uniform illumination optical system 3 in which the first fly-eye lens, the second fly-eye lens, the polarization conversion element, and the condenser lens are sequentially installed. The first and second fly-eye lenses and the condensing lens have a function of making the light intensity distribution in the cross section of the light beam uniform. The polarization conversion element is composed of, for example, a PBS array and a half-wave plate, and the vibration direction is unidirectional so that the indefinitely polarized light beam emitted from the light source 2 can be used in the subsequent optical system. Convert to uniform linear polarization. The light beam emitted from the uniform illumination optical system 3 is converted into P-polarized light by a polarization conversion element inside the uniform illumination optical system 3.
In order to simplify the drawing, the uniform illumination optical system is simplified in FIG. 1 as if it were one component.

   As shown in FIG. 2, the light beam emitted from the uniform illumination optical system 3 enters the PBS 4, and the P-polarized component passes through the PBS film 4a and enters the reflective liquid crystal light valve 5 (first light modulation element). The reflective liquid crystal light valve 5 modulates and emits the luminance in the entire wavelength region of the incident light according to the video signal. Specifically, the P-polarized light incident on the reflective liquid crystal light valve 5 is phase-modulated according to the video signal, and the S-polarized component of the light beam reflected and incident again on the PBS 4 is reflected by the PBS film 4a and relayed. The light is emitted toward the lens 6. The relay lens 6 has a function of forming an optical image of the reflective liquid crystal light valve 5 for luminance modulation on the pixel surfaces of the transmissive liquid crystal light valves 10R, 10G, and 10B for color modulation.

  The light beam emitted from the relay lens 6 is incident on the color separation unit located below the color separation / combination prism 7 (color separation / combination element). As shown in FIG. 2, the color separation / combination prism 7 includes a G light prism 7G (green light prism), a B light prism 7B (blue light prism), and an R light prism 7R (red light prism). It consists of three prisms. The white light beam incident on the R light prism 7R is incident on the interface between the B light prism 7B and the R light prism 7R. A dichroic film having a characteristic of G / B transmission / R reflection (transmitting G light and B light and reflecting R light) is formed on this interface, and the reflected R light flux is converted into an R light prism 7R. After being incident on the total reflection surface and reflected again, it is emitted from the R light prism 7R.

  The G / B light beam incident on the B light prism 7B enters the interface between the B light prism 7B and the G light prism 7G. A dichroic film having G transmission / B reflection characteristics is formed on this interface, and the B light beam reflected there is incident on the total reflection surface of the B light prism 7B and reflected again, and then the B light prism. The light is emitted from 7B. The G light beam incident on the G light prism 7G enters the total reflection surface of the G light prism 7G, is reflected again, and then exits from the G light prism 7G.

  The R, G, and B color beams emitted from the color separation / combination prism 7 are lifted upward (in the + y direction) by the lower mirror 8 (light transmission optical system), and then incident on the upper mirror 9 (light transmission optical system). And is incident on three transmissive liquid crystal light valves 10R, 10G, and 10B (second light modulation elements) disposed opposite to the light incident surface of the color combining unit 7b positioned above the color separation / combination prism 7. To do. Therefore, a pair of mirrors including the lower mirror 8 and the upper mirror 9 function as a light transmission optical system that transmits each color light emitted from the color separation unit of the color separation / combination prism 7 to each transmission type liquid crystal light valve 10. The pair of mirrors including the lower mirror 8 and the upper mirror 9 includes a position adjustment mechanism that adjusts the position of each mirror 8 and 9 and the angle of the reflecting surface with respect to the incident optical axis (rotation angle about the x, y, and z axes). 12R, 12G, and 12B (light transmission optical system position adjusting means) are provided.

  Further, the prisms constituting the color separation / combination prism 7 in this embodiment have the same configuration at the top and bottom, and nothing changes, but the lower part converts the incident white light into the three primary color lights of R, G, and B. The upper part functions as a color synthesizing unit that synthesizes and emits the three primary color lights of R, G, and B incident from three directions. In the following text, the three transmissive liquid crystal light valves 10R, 10G, and 10B may be collectively referred to as the color modulation light valve 10 as necessary.

  The transmissive liquid crystal light valves 10R, 10G, and 10B (second light modulation elements) include a pixel substrate and a glass substrate on which switching elements such as a thin film transistor element and a thin film diode for driving the pixel electrode are formed in a matrix, and the entire surface. This is an active matrix liquid crystal display element in which a twisted nematic (TN) type liquid crystal is sandwiched between a glass substrate on which a common electrode is formed and a polarizing plate is disposed on both outer surfaces. The transmissive liquid crystal light valves 10R, 10G, and 10B have a normally white mode in which a white / bright (transmission) state is applied when no voltage is applied, and a black / dark (non-transmission) state when a voltage is applied, or vice versa. It is driven in the black mode, and the gradation between light and dark is analog controlled according to a given control value.

  Each color light beam incident on the color modulation light valve 10 undergoes modulation (second modulation) corresponding to the video signal, and is incident on the color separation / combination prism 7 again to be combined. Subsequently, the combined light beam enters a projection lens 11 (projection optical system) located above the relay lens 6 and is projected onto a screen (not shown) by the projection lens 11.

  Hereinafter, a method for manufacturing the projector of the present embodiment having the above-described configuration will be described with reference to the flowchart of FIG. Below, the position adjustment process of the 1st and 2nd light modulation element which is the feature point of this invention is demonstrated in detail among all the manufacturing processes, and description is abbreviate | omitted about the other process in which a general method is used.

In the projector of the present embodiment, the positions of the four liquid crystal light valves 5, 10R, 10G, and 10B constituting the light modulation element are adjusted by the following procedure.
First, the position of the three transmissive liquid crystal light valves 10R, 10G, and 10B for color modulation is adjusted with respect to the projection lens 11 using the same method as that of a normal three-plate projection display device (FIG. 3). Step S1).
When the position adjustment is completed, the transmissive liquid crystal light valves 10R, 10G, and 10B are fixed to the color separation / combination prism 7 (step S2 in FIG. 3).

  Next, the color separation / synthesizing prism 7 and the projection lens 11 to which the three color modulation transmission type liquid crystal light valves 10R, 10G, and 10B are fixed, the reflection type liquid crystal light valve 5, the PBS 4, and the relay lens 6 are shown in FIG. Incorporated into the optical system arranged in the layout (2). Then, adjustment is performed so that the optical image of the reflective liquid crystal light valve 5 formed by the relay lens 6 is formed at a predetermined position on the pixel surface of each of the transmissive liquid crystal light valves 10R, 10G, and 10B for color modulation. . At this time, the inclination and position of the lower mirrors 8R, 8G, 8B and the upper mirrors 9R, 9G, 9B arranged on the optical paths of the R, G, B color lights using the position adjusting mechanisms 12R, 12G, 12B are determined. Adjustment is made (step S3 in FIG. 3). The inclination and position adjustment are performed so that the light beam is shifted in the horizontal direction and the vertical direction of the color modulation light valve 10. Since there are two mirrors in each optical path, the position adjustment mechanism is simplified by sharing the horizontal direction adjustment and the vertical direction adjustment respectively, and the apparatus cost can be reduced.

  Position adjustment is performed, and when the optical image of the reflective liquid crystal light valve 5 is formed at predetermined positions on the pixel surfaces of the transmissive liquid crystal light valves 10R, 10G, and 10B for color modulation, the lower mirror 8 and the upper mirror 9 The inclination and position are fixed (step S4 in FIG. 3).

  According to the present embodiment, the position adjustment mechanisms 12R, 12G, and 12B for adjusting the positions and inclinations of the lower mirror 8 and the upper mirror 9 are provided in the R, G, and B optical paths, respectively, and therefore, three color modulations are performed. After adjusting the positions of the light valves 10R, 10G, and 10B with respect to the projection lens 11, the relay optical image of the luminance modulation light valve 5 can be aligned with the color modulation light valves 10R, 10G, and 10B independently for each color. . Thereby, accurate alignment of each light valve and accurate luminance modulation are possible, and a projector capable of displaying an image with excellent image quality without coloring or color unevenness can be realized.

  The color separation / combination prism 7 is composed of three prisms: an R-light prism 7R, a G-light prism 7G, and a B-light prism 7B. Since accuracy is not required, it becomes easier to adjust the image formation position of the relay optical image of the luminance modulation light valve 5 than when a cross dichroic prism is used, and image quality deterioration can be prevented more reliably.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
As in the first embodiment, this embodiment is also an example of a liquid crystal projector including a reflective liquid crystal light valve for luminance modulation and three transmissive liquid crystal light valves for color modulation.
FIG. 4 is a plan view of the projector according to the present embodiment. FIG. 3 is a flowchart showing a manufacturing process of the projector. In FIG. 4, the same components as those in FIG. 2 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the first embodiment, the position adjustment mechanism is provided in the lower mirror and the upper mirror in all the optical paths of R, G, and B, whereas in the projector 21 of the present embodiment, as shown in FIG. , G, and B, the lower mirrors 8R and 8B and the upper mirrors 9R and 9B of the R and B optical paths are provided with position adjusting mechanisms 12R and 12B (light transmission optical system position adjusting means). The lower mirror 8G and the upper mirror 9G of the G optical path are not provided with a position adjusting mechanism. A position adjusting mechanism 14 (first light modulating element position adjusting means) for adjusting the position of the reflective liquid crystal light valve 5 for luminance modulation is provided. The position adjustment mechanism 14 allows the reflective liquid crystal light valve 5 to move forward or backward in the x, y, and z axis directions and to rotate about the x, y, and z axes.

Hereinafter, a method for manufacturing the projector 21 of the present embodiment having the above-described configuration will be described with reference to the flowchart of FIG.
In the projector 21 of the present embodiment, the positions of the four liquid crystal light valves 5, 10R, 10G, and 10B constituting the light modulation element are adjusted by the following procedure.
First, the positions of the three transmissive liquid crystal light valves 10R, 10G, and 10B for color modulation are respectively adjusted with respect to the projection lens 11 using the same technique as that of a normal three-plate projection display device (FIG. 5). Step S1).
When the position adjustment is completed, the transmissive liquid crystal light valves 10R, 10G, and 10B are fixed to the color separation / combination prism 7 (step S2 in FIG. 5). The steps up to this are the same as in the first embodiment.

Next, the relative position of the reflective liquid crystal light valve 5 with respect to the relay lens 6 is moved by using the position adjusting mechanism 14, so that one transmissive liquid crystal light valve for color modulation (in this case, a liquid crystal light valve for G light). The position is adjusted so that the relay optical image of the reflective liquid crystal light valve 5 for luminance modulation is formed at a predetermined position (pixel surface) of 10G) (step S3 in FIG. 5).
When the position adjustment is completed, the reflective liquid crystal light valve 5 is fixed to, for example, the PBS 4 (step S4 in FIG. 5).

  However, at the stage where this adjustment is completed, the other two color modulation transmission type liquid crystal light valves (in this example, R, B light liquid crystal light valves 10R, 10B) are in a predetermined position (pixels). The optical image of the reflective liquid crystal light valve 5 is not formed on the surface. This is because there is a difference in refractive index between the three prisms 7R, 7G, and 7B of the color separation / combination prism 7, and there is an error in the mounting accuracy of the lower mirror 8 and the upper mirror 9.

  Therefore, in the next stage, the position adjustment mechanisms 12R and 12B are used to adjust the tilt and position of the lower mirrors 8R and 8B and the upper mirrors 9R and 9B provided in the optical paths of the R and B color lights (FIG. 5 step S5). The inclination and position adjustment are performed so that the light flux shifts in the horizontal direction and the vertical direction of the transmissive liquid crystal light valves 10R and 10B for color modulation. Since there are two mirrors in each optical path, the position adjustment mechanism is simplified by sharing the horizontal direction adjustment and the vertical direction adjustment respectively, and the apparatus cost can be reduced.

  Position adjustment is performed, and when the optical image of the reflective liquid crystal light valve 5 is formed at a predetermined position on the pixel surface of the transmissive liquid crystal light valves 10R and 10B for color modulation, the lower mirrors 8R and 8B and the upper mirrors 9R and 9B. Is fixed (step S6 in FIG. 5).

  Also in the present embodiment, it is possible to realize a projector capable of displaying an image with excellent image quality without coloring or color unevenness by enabling accurate alignment and accurate luminance modulation of each light valve. Similar effects can be obtained. Further, the position adjustment mechanism for the lower mirror and the upper mirror need only have two optical paths, R and B, and the position adjustment mechanism can be reduced. In this embodiment, it may seem that the position adjustment mechanism of the reflection type liquid crystal light valve is increased as compared with the first embodiment. However, as an actual device, even in the case of the first embodiment, the reflection type liquid crystal A light valve position adjusting mechanism is necessary (in the first embodiment, the description is omitted because it is not related to the point of the invention). Therefore, according to the configuration of the present embodiment, the device configuration can be simplified.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, a configuration including three prisms, that is, an R-light prism, a G-light prism, and a B-light prism is shown as the color separation / combination prism, but a cross dichroic prism may be used instead of this configuration. . In addition, a transmissive liquid crystal light valve may be used as the first light modulation element instead of the reflective liquid crystal light valve. Further, the first light modulation element is not limited to the liquid crystal light valve, and DMD or the like can also be used.

1 is a perspective view showing a projector according to a first embodiment of the present invention. It is the same top view. It is a flowchart which shows the manufacturing method of the projector. It is a top view which shows the projector of 2nd Embodiment of this invention. It is a flowchart which shows the manufacturing method of the projector.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,21 ... Projector, 2 ... Light source, 5 ... Reflection type liquid crystal light valve (first light modulation element), 7 ... Color separation / combination prism (color separation / synthesis element), 7R ... R light prism, 7G ... G light Prism, 7B... B light prism, 8, 8R, 8G, 8B... Lower mirror (light transmission optical system), 9, 9R, 9G, 9B... Upper mirror (light transmission optical system) 10, 10R, 10G, DESCRIPTION OF SYMBOLS 10B ... Transmission-type liquid crystal light valve (2nd light modulation element), 11 ... Projection lens (projection optical system), 12R, 12G, 12B ... Position adjustment mechanism (light transmission optical system position adjustment means), 14 ... Position adjustment mechanism ( First light modulation element position adjusting means).

Claims (5)

A light source;
A first light modulation element that modulates light emitted from the light source;
A plurality of second light modulation elements that respectively modulate a plurality of color lights in different wavelength ranges in which the light emitted from the first light modulation element is separated by a wavelength range;
Color separation having a color separation unit that separates light modulated by the first light modulation element into the plurality of color lights and a color synthesis unit that combines the plurality of color lights modulated by the plurality of second light modulation elements・ Synthetic element,
A plurality of light transmission optical systems that respectively transmit each color light emitted from the color separation unit of the color separation / synthesis element to the plurality of second light modulation elements;
A projection optical system for projecting an image composed of synthesized light synthesized by the color synthesis unit of the color separation / synthesis element;
A projector comprising: a light transmission optical system position adjusting unit configured to adjust a position of each of the plurality of light transmission optical systems. A light source;
A first light modulation element that modulates light emitted from the light source;
A plurality of second light modulation elements that respectively modulate a plurality of color lights in different wavelength ranges in which the light emitted from the first light modulation element is separated by a wavelength range;
Color separation having a color separation unit that separates light modulated by the first light modulation element into the plurality of color lights and a color synthesis unit that combines the plurality of color lights modulated by the plurality of second light modulation elements・ Synthetic element,
A plurality of light transmission optical systems that respectively transmit each color light emitted from the color separation unit of the color separation / synthesis element to the plurality of second light modulation elements;
A projection optical system for projecting an image composed of synthesized light synthesized by the color synthesis unit of the color separation / synthesis element;
A light transmission optical system position adjusting means for adjusting the position of each of the other light transmission optical systems other than one of the plurality of light transmission optical systems;
A projector comprising: first light modulation element position adjusting means for adjusting a position of the first light modulation element. The plurality of color lights are red light, green light, blue light,
The color separation / synthesis element includes a red light prism, a green light prism, and a blue light prism,
The red light prism includes a wavelength selective reflection surface that reflects the red light and transmits the green light and the blue light out of the light emitted from the first light modulation element, and the wavelength selective reflection surface. A total reflection surface that totally reflects the reflected red light toward a predetermined optical path toward the second light modulation element;
The blue light prism reflects the blue light transmitted through the wavelength selective reflection surface of the red light prism and transmits the green light, and the blue light reflected at the wavelength selective reflection surface. And a total reflection surface that totally reflects toward a predetermined optical path toward the second light modulation element,
The projector according to claim 1, wherein the green light prism has a total reflection surface that totally reflects the green light transmitted through the wavelength selective reflection surface of the blue light prism. A light source, a first light modulation element that modulates the light emitted from the light source, and a plurality of light components that respectively modulate a plurality of color lights in different wavelength ranges in which the light emitted from the first light modulation element is separated by a wavelength range The second light modulation element, a color separation unit that separates the light modulated by the first light modulation element into the plurality of color lights, and the plurality of color lights modulated by the plurality of second light modulation elements. A color separating / synthesizing element having a color synthesizing unit, and a plurality of light transmission optical systems for transmitting each color light emitted from the color separating unit of the color separating / synthesizing element to the plurality of second light modulation elements, respectively. A projection optical system for projecting an image composed of synthesized light synthesized by a color synthesizing unit of the color separation / synthesis element, and a manufacturing method of a projector comprising:
Adjusting the position of each of the plurality of second light modulation elements with respect to the projection optical system;
Adjusting the position of the optical image of the first light modulation element with respect to each of the plurality of second light modulation elements by adjusting the position of each of the plurality of light transmission optical systems. A method for manufacturing a projector, comprising: A light source, a first light modulation element that modulates the light emitted from the light source, and a plurality of light components that respectively modulate a plurality of color lights in different wavelength ranges in which the light emitted from the first light modulation element is separated by a wavelength range The second light modulation element, a color separation unit that separates the light modulated by the first light modulation element into the plurality of color lights, and the plurality of color lights modulated by the plurality of second light modulation elements. A color separating / synthesizing element having a color synthesizing unit, and a plurality of light transmission optical systems for transmitting each color light emitted from the color separating unit of the color separating / synthesizing element to the plurality of second light modulation elements, respectively. A projection optical system for projecting an image composed of synthesized light synthesized by a color synthesizing unit of the color separation / synthesis element, and a manufacturing method of a projector comprising:
Adjusting the position of each of the plurality of second light modulation elements with respect to the projection optical system;
By adjusting the position of the first light modulation element, the position of the optical image of the first light modulation element is aligned with one second light modulation element of the plurality of second light modulation elements. Process,
Of the plurality of light transmission optical systems, by adjusting the position of the other light transmission optical system excluding one light transmission optical system corresponding to the one second light modulation element, the first light modulation element And a step of aligning the position of the optical image with each of the other second light modulation elements other than the one second light modulation element.

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