JP2010014923A - Projector, projection system and position adjusting method for light modulating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect positional shifting of a light modulating element without specially machining components originally provided in a projector and to install a detecting part for detecting positional shifting in a position not to intercept the projection light. <P>SOLUTION: This projector includes: polarized light separating means 115R, 115G, 115B for separating unnecessary polarized light components not required for projection among the polarized light components of each image light emitted from a plurality of light modulating elements corresponding to the different color components; image sensors 130R, 130G, 130B for outputting image data corresponding to the unnecessary polarized light components; position adjusting mechanisms 140R, 140G, 140B capable of adjusting the positions of the respective light modulating elements; and a position adjusting control device 150 for the light modulating elements, which includes a positional shifting calculating part 151 for calculating the positional shifting direction and the positional shifting amount of each light modulating element based on the image data output from the image sensor and a position adjusting mechanism part 152 for controlling the position adjusting mechanisms 140R, 140G, 140B based on the calculated positional shifting direction and positional shifting amount. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projector, a projection system, and a position adjustment method for a light modulation element that enable position adjustment of a plurality of light modulation elements corresponding to a plurality of color components.

  In recent years, projectors tend to have higher resolution and higher brightness. In such a projector, in order to increase the resolution, it is necessary to narrow the pixel pitch of the light modulation element (referred to as a liquid crystal panel). Therefore, in a so-called three-plate type liquid crystal projector using three liquid crystal panels corresponding to a plurality of color components (three RGB color components), in order to align the pixels of each liquid crystal panel, each liquid crystal panel It is necessary to adjust the position of the lens with extremely high accuracy. Further, since the heat generation from the optical system increases due to the increase in brightness, there is a problem that the position of each liquid crystal panel is shifted due to a temperature change even if the position of each liquid crystal panel is adjusted with high accuracy.

  In view of this, various position adjustment techniques for correcting misalignment of a plurality of liquid crystal panels in a projector using a plurality of liquid crystal panels have been proposed (see, for example, Patent Document 1 and Patent Document 2).

  The technique disclosed in Patent Document 1 (referred to as the first conventional technique) captures a projected image on a screen with an imaging device, and determines the displacement direction and displacement amount of each liquid crystal panel based on the captured image data. The positional deviation of the liquid crystal panel is corrected by detecting and adjusting the position of the liquid crystal panel by an electric fine movement means such as a piezoelectric element.

However, in the first prior art, when a positional deviation of each liquid crystal panel occurs during image projection, it is not studied to adjust it in real time. This is because it is difficult to detect a positional shift of each liquid crystal panel from image data obtained by capturing a general image that is not a test image for position adjustment.
On the other hand, the technique (referred to as the second conventional technique) disclosed in Patent Document 2 enables the position adjustment of each liquid crystal panel in real time even during image projection.

JP-A-8-262565 Japanese Patent Laid-Open No. 9-146062

  In the second prior art, four holes (referred to as detection holes) that can transmit light are provided at four corners outside the image forming area (effective pixel area) in each liquid crystal panel, and each detection hole is transmitted. A light detection means for detecting light is provided immediately in front of the projection lens, and light (light from the light source of the projector) transmitted through each detection hole is detected by the light detection means. Based on the detection result, a piezoelectric element or the like is detected. The position of each liquid crystal panel is finely adjusted by the electric fine movement means. Each of the light detection means provided corresponding to each of the four detection holes has a plurality of photodiodes, and the positional deviation direction of each liquid crystal panel and the magnitude of the output of these photodiodes A positional deviation amount is obtained, and fine adjustment is performed based on the obtained positional deviation direction and positional deviation amount.

As described above, according to the second prior art, since the position shift of each liquid crystal panel is detected using light different from the projected image (light from the light source of the projector), in real time even during image projection. The position of each liquid crystal panel can be adjusted.

  However, in the second prior art, since it is necessary to bother to provide a hole that does not exist in the conventional liquid crystal panel as a detection hole, an extra process must be added when manufacturing the liquid crystal panel. This may lead to an increase in production costs and a decrease in yield rate. In addition, since the light detection means has a structure provided immediately before the projection lens, the light detection means exists along the optical path of the projection light, and the light detection means may block a part of the projection image. There can be sex.

  In view of this, the present invention provides detection means for detecting misalignment at a position where it is possible to detect the amount of misalignment in real time without applying special processing to the components that the projector originally has, and not to block the projection light. It is an object of the present invention to provide a projector, a projection system, and a light modulation element position adjusting method that can be installed.

  The projector of the present invention is a projector having a plurality of light modulation elements corresponding to different color components and a combining optical system for combining the image lights emitted from the light modulation elements of the plurality of light modulation elements. A polarization separation means for separating unnecessary polarization components unnecessary for projection out of the polarization components of each image light emitted from each of the light modulation elements, and receiving the separated unnecessary polarization components by receiving the separated unnecessary polarization components An image sensor that outputs image data corresponding to a component; a position adjustment mechanism that can adjust the position of each light modulation element for each light modulation element; and each light based on image data output from the image sensor. A position shift calculation unit for calculating a position shift direction and a position shift amount of the modulation element, and the position based on the position shift direction and the position shift amount calculated by the position shift calculation unit. And having a positioning control device of the light modulation element having a position adjusting mechanism control unit for controlling an integer mechanism.

  According to the projector of the present invention, it is not necessary to perform special processing on the optical component itself that the projector originally has, such as providing a position detection hole in the light modulation element, and the optical component that the projector originally has is maximized. By utilizing this, a position adjusting mechanism for the light modulation element can be incorporated.

  In addition, the position adjustment control device for the light modulation element that controls the position adjustment mechanism can be realized only by adding a calculation function necessary for position adjustment to the image processing apparatus that the projector originally has. Further, the image sensor detects an unnecessary polarization component separated by the polarization separation means, and therefore can be installed at a position off the optical path of the projected image. Thereby, the malfunction that the image sensor as a detection part for position shift detection blocks a projection image can be prevented reliably.

In the projector according to the aspect of the invention, it is preferable that the polarization separation unit is provided between each of the light modulation elements and the combining optical system.
In this way, by providing the polarization separating means between each light modulation element and the combining optical system, unnecessary polarization components unnecessary for projection among the polarization components of each image light emitted from each light modulation element are provided. Since the light modulation elements can be separated, the position shift direction and the position shift amount of each light modulation element can be calculated for each light modulation element.

In the projector according to the aspect of the invention, it is preferable that the polarization separation unit separates the unnecessary polarization component in a direction orthogonal to the optical axis of the image light output from each light modulation element.
By using such polarization separation means, each image sensor can be installed at a position off the optical path of the image light for projection (image light output from each light modulation element). It is possible to prevent problems such as blocking a part of image light for projection. An example of the polarization separation means is a polarization beam splitter.

  In the projector according to the aspect of the invention, the misregistration calculation unit may determine the image data output from the image sensor based on image data corresponding to a non-image forming area existing outside the image forming area of each light modulation element. It is preferable to detect the edge position of the non-image forming area and calculate the position shift direction and the position shift amount based on the detected edge position.

Thus, by calculating the position shift direction and the amount of position shift based on the edge position of the non-image forming region, the position shift direction and the position shift amount of each light modulation element can be calculated with high accuracy.
Further, by calculating the position shift direction and the position shift amount using the image data corresponding to the non-image forming area, the position shift direction of each light modulation element and the position of each light modulation element without affecting the projected image even during image projection. The positional deviation amount can be detected, and the positional deviation correction with respect to the detected positional deviation direction and positional deviation amount can be performed. Therefore, it is not necessary to project a test image or the like for positional deviation correction, and even when a positional deviation of the light modulation element occurs during image projection, correction can be performed in real time.

  In the projector according to the aspect of the invention, the edge position of the non-image forming region when each light modulation element is set to a reference position without a position shift is calculated in advance as a reference position of each light modulation element, and the position shift calculation is performed. The position of the light modulation element at the current time based on the edge position of the non-image forming region obtained based on the image data output from the image sensor at the current time and the reference position of each of the light modulation elements It is preferable that a displacement direction and a displacement amount are calculated, and the position adjustment mechanism control unit controls the position adjustment mechanism so as to correct the calculated displacement direction and displacement amount.

  This is because the edge position of each non-image forming area when each light modulation element is set to a reference position without positional deviation is calculated in advance as the reference position of each light modulation element, and the position adjustment is performed. Is to calculate the current displacement direction and displacement amount of the liquid crystal panel from the edge position of the non-image display area detected at the current time and the reference position of each light modulation element calculated in advance. By calculating the position shift direction and the position shift amount in this way, the position shift direction and the position shift amount with respect to the reference position of each light modulation element can be calculated with high accuracy. By correcting the positional shift of each light modulation element based on the calculated positional shift direction and positional shift amount, it is possible to eliminate the shift of the corresponding pixel of each light modulation element.

In the projector according to the aspect of the invention, it is preferable that the image sensor has a light detection element disposed so as to be able to receive unnecessary polarization components in a region including the entire non-image forming region.
As a result, image data corresponding to the entire non-image forming area can be obtained, and by calculating the edge position of the non-image forming area using such image data, the edge position of the non-image forming area can be increased. It can be calculated with accuracy.

  In the projector according to the aspect of the invention, it is also preferable that the image sensor is provided with a light detection element so as to be able to receive an unnecessary polarization component in a specific portion of the non-image forming region.

Even if the image sensor has such a configuration, it is possible to appropriately detect the edge position of the non-image forming region. Further, by adopting such an image sensor structure, the number of photodetecting elements can be greatly reduced, so that the image sensor can be made inexpensive. Further, since the data amount of the output image data is also reduced, it is possible to reduce the calculation amount necessary for detecting the edge position of the non-image forming area. Note that the specific portion of the non-image forming area is preferably a peripheral area including the “corner portion” of the non-image forming area, for example.

  In the projector according to the aspect of the invention, the position adjustment mechanism can move the light modulation element in the vertical direction and the horizontal direction on a plane orthogonal to the optical axis of the image light output from the light modulation elements. It is preferable to have a mechanism that allows the light modulation element to rotate clockwise and counterclockwise around the optical axis of the image light on a plane.

  Since the position adjusting mechanism has such a mechanism, each light modulation element can be moved by a predetermined amount in the vertical and horizontal directions on a plane orthogonal to the optical axis, and the light of the image light can be moved on the plane. It can be rotated by a predetermined angle in the clockwise direction and the counterclockwise direction around the axis. Thereby, the position shift of each light modulation element can be appropriately corrected based on the position shift direction and the position shift amount calculated by the position shift calculation unit.

  The projection system of the present invention includes a projector having a plurality of light modulation elements corresponding to different color components, and a combining optical system for combining the image lights emitted from the light modulation elements of the plurality of light modulation elements, , A light modulation element position adjustment control device that performs position adjustment control of each light modulation element, wherein the projector includes a polarization component of each image light emitted from each light modulation element A polarization separation unit that separates unnecessary polarization components unnecessary for projection; an image sensor that receives the separated unnecessary polarization components; and outputs image data corresponding to the received unnecessary polarization components; and A position adjustment mechanism capable of adjusting the position of each light modulation element, and the position adjustment control device for the light modulation element is output from the image sensor. A position shift calculation unit that calculates a position shift direction and a position shift amount of each of the light modulation elements based on the image data, and the position adjustment based on the position shift direction and the position shift amount calculated by the position shift calculation unit. And a position adjustment mechanism control unit for controlling the mechanism.

  This is a case where the position adjustment control device for the light modulation element is provided separately from the projector, and illustrates the case where the function of the position adjustment control device for the light modulation element is incorporated in an information processing device such as a personal computer. Can do. As described above, even when the projection system is configured by the projector and the position adjustment control device for the light modulation element, the same effect as that of the projector of the present invention can be obtained. Note that the projection system of the present invention preferably has the characteristics of the projector of the present invention.

  The light modulation element position adjusting method according to the present invention includes a plurality of light modulation elements corresponding to different color components and a composite optical system for combining image lights emitted from the light modulation elements of the plurality of light modulation elements. And polarization separating means for separating unnecessary polarization components unnecessary for projection out of the polarization components of each image light emitted from each light modulation element, and receiving the separated unnecessary polarization components. Light modulation for adjusting the position of each light modulation element in a projector having an image sensor that outputs image data corresponding to a component and a position adjustment mechanism capable of adjusting the position of each light modulation element for each light modulation element An element position adjusting method, comprising: calculating a position shift direction and a position shift amount of each light modulation element based on image data output from the image sensor; Characterized by a step of controlling the position adjusting mechanism based on the positional deviation direction and the positional deviation amount was.

By adjusting the position of each light modulation element by such a position adjustment method, the position adjustment of each light modulation element can be performed appropriately and with high accuracy. In the light modulation element position adjusting method of the present invention, it is preferable that the projector has the respective characteristics.

  Hereinafter, embodiments of the present invention will be described.

[Embodiment 1]
FIG. 1 is a diagram illustrating a configuration of a projector according to the first embodiment. As shown in FIG. 1, the projector according to the first embodiment (referred to as projector PJ1) includes a light source 101, an integrator lens 102, a polarization conversion element 103, lenses 104 to 106, a first dichroic mirror 107, a second dichroic mirror 108, Reflecting mirrors 109 to 111, polarizing plates 112R, 112G, and 112B that transmit light in one polarization direction (P-polarized light or S-polarized light) and absorb light in the other polarizing direction (S-polarized light or P-polarized light) 1 / 2λ plates 113R and 113B for converting P-polarized light to S-polarized light or S-polarized light to P-polarized light, cross dichroic prism 114 as a combining optical system, polarizing beam splitters (referred to as PBS) 115R, 115G, and 115B as polarization separating means, Projection lens 116 as a projection optical system, R (red), G (green), Image sensors 130R and 130G provided to receive light of unnecessary polarization components reflected by the liquid crystal panels 120R, 120G, and 120B and PBSs 115R, 115G, and 115B as light modulation elements corresponding to each color component of B (blue). , 130B, position adjustment mechanisms 140R, 140G, 140B that can finely adjust the positions of the liquid crystal panels 120R, 120G, 120B, and the liquid crystal panels 120R, 120G, 120B based on the image data output from the image sensors 130R, 130G, 130B. It has a light modulation element position adjustment control device 150 that performs 120B position adjustment control.

  In each figure used in the description of each embodiment of the present invention, “(// P)” attached to each polarizing plate means that P-polarized light is transmitted and S-polarized light is absorbed. “(// S)” means transmitting S-polarized light and absorbing P-polarized light.

  The light modulation element position adjustment control device 150 calculates a position shift direction and a position shift amount of each of the liquid crystal panels 120R, 120G, and 120B based on image data output from the image sensors 130R, 130G, and 130B. 151, a position adjustment mechanism control unit 152 that controls the position adjustment mechanisms 140R, 140G, and 140B based on the position shift direction and the amount of position shift calculated by the position shift calculation unit 151, and the reference of each of the liquid crystal panels 120R, 120G, and 120B And a storage unit 153 that stores various data such as a position shift direction and a position shift amount calculated by the position shift calculation unit 151. The operations of the image sensors 130R, 130G, and 130B, the structures of the position adjustment mechanisms 140R, 140G, and 140B, and specific operations of the position deviation calculation unit 151 and the position adjustment mechanism control unit 152 will be described later.

  In such a configuration, after the luminance distribution of the light emitted from the light source 101 is made almost uniform by the integrator lens 102, the polarization direction is adjusted by the polarization conversion element 103, and the light having a predetermined polarization direction (S-polarized light) is obtained. Light is emitted. Thereafter, the first dichroic mirror 107 separates the light of the R color component (referred to as R color light), the light of the G color component (referred to as G color light), and the light of the B color component (referred to as B color light).

The R color light separated by the first dichroic mirror 107 is reflected by the reflection mirror 109, passes through the ½λ plate 113R and the polarizing plate 112R, and enters the liquid crystal panel 120R. The R color light incident on the liquid crystal panel 120R is modulated based on image data and output as image light (referred to as R image light), and then a polarization component unnecessary for projection (referred to as an unnecessary polarization component) is separated by the PBS 115R. Then, a polarization component necessary for projection is incident on the cross dichroic prism 114.

  The G color light and B color light separated by the first dichroic mirror 107 are separated into G color light and B color light by the second dichroic mirror 108. The G color light separated by the second dichroic mirror 108 passes through the polarizing plate 112G and enters the liquid crystal panel 120G. The G color light incident on the liquid crystal panel 120G is modulated based on the image data and output as image light (referred to as G image light). Then, unnecessary polarization components are separated by the PBS 115G, and the polarization components necessary for projection are crossed. The light enters the dichroic prism 114.

  Further, the B-color light separated by the second dichroic mirror 108 is reflected by the reflection mirror 111 via the lens 105, the reflection mirror 110, and the lens 106 constituting the relay optical system. The B color light incident on the liquid crystal panel 120B is transmitted through the 1 / 2λ plate 113B and the polarizing plate 112B, is incident on the liquid crystal panel 120B, is modulated based on the image data, and is output as image light (referred to as B image light). After that, the unnecessary polarization component is separated by the PBS 115B, and the polarization component necessary for projection is incident on the cross dichroic prism 114.

  In this manner, the RGB image lights incident on the cross dichroic prism 114 are combined by the cross dichroic prism 114 and emitted as composite image light, and are projected onto a projection surface (not shown) by the projection lens 116. .

  By the way, the cross dichroic prism 114 may be designed so that the R image light and the B image light are incident as S-polarized light and the G image light is incident as P-polarized light for the purpose of increasing the luminance. In this way, the polarization direction of each image light incident on the cross dichroic prism 114 is such that the cross dichroic prism 114 has high reflection characteristics with respect to S polarization in the optical path of the R image light and the optical path of the B image light. However, in the optical path of the G image light that is transmitted light, P-polarized light can be given a wider transmission bandwidth than S-polarized light, which is advantageous in terms of increasing luminance. Because. Therefore, in order to match the polarization directions of the RGB image lights in this way, a 1 / 2λ plate 113R is provided on the optical path of the R color light, and a 1 / 2λ plate 113B is provided on the optical path of the B color light. Yes.

  With such a configuration, in FIG. 1, when viewed from the cross dichroic prism 114, the R image light and the B image light are incident on the cross dichroic prism 114 as S-polarized light, and the G image light is P-polarized light. Is incident.

  In a conventional general projector having an optical system in which R image light and B image light are incident on S-polarized light and G image light is incident on P-polarized light with respect to the cross dichroic prism, each of the RGB liquid crystal panels In general, R and B image lights are incident on a cross dichroic prism as S-polarized light and G-image light as P-polarized light by a polarizing plate provided on the exit side (see FIG. 2). .

  FIG. 2 is a diagram showing a configuration of an optical system of a general projector in which R image light and B image light are incident on a cross dichroic prism with S polarization and G image light with P polarization. That is, in the projector (projector PJ1 ′) shown in FIG. 2, a polarizing plate 117R that transmits S-polarized light and absorbs P-polarized light is provided on the exit side of the liquid crystal panel 120R, and also on the exit side of the liquid crystal panel 120B. A polarizing plate 117B that transmits S-polarized light and absorbs P-polarized light is provided. A polarizing plate 117G that transmits P-polarized light and absorbs S-polarized light is provided on the exit side of the liquid crystal panel 120G. In FIG. 2, the same components as those in FIG.

  In the general projector PJ1 ′ shown in FIG. 2, the P-polarized light is absorbed by the polarizing plates 117R and 117B provided on the emission side of the liquid crystal panels 120R and 120B in the optical paths of the R color light and the B color light, and the cross dichroic prism 114 is used. S-polarized R image light and B image light are incident on the light source, and in the optical path of G-color light, the S-polarized light is absorbed by the polarizing plate 117G provided on the exit side of the liquid crystal panel 120G, and is incident on the cross dichroic prism 114. P-polarized G image light is incident.

  On the other hand, the projector PJ1 according to the first embodiment of the present invention includes PBSs 115R, 115G, and 115B instead of the polarizing plates 117R, 117G, and 117B shown in FIG. 2 (see FIG. 1). By so doing, unnecessary polarization components that are originally absorbed by the polarizing plates 117R, 117G, and 117B on the emission side are reflected by the PBSs 115R, 115G, and 115B in a direction orthogonal to the optical paths of the RGB image lights. The reflected unnecessary polarization component can be separated and extracted from the image light for projection. Unnecessary polarization components of RGB images separated from the image light for projection are received by image sensors 130R, 130G, and 130B provided corresponding to the PBSs 115R, 115G, and 115B, respectively.

  That is, in the R image light and the B image light, the unnecessary polarization component reflected by the PBSs 115R and 115B is perpendicular to the traveling direction of the image light (the direction along the x axis in FIG. 1) (z axis in FIG. 1). ) And enter the image sensors 130R and 130B (see FIG. 3). On the other hand, in the G image light, as shown in FIG. 1, the unnecessary polarization component reflected by the PBS 115G is perpendicular to the traveling direction of the G image light (the direction along the y axis in FIG. 1) (in FIG. 1). travels in the direction along the x-axis) and enters the image sensor 130G.

  FIG. 3 is a view of FIG. 1 as viewed in the direction of the arrow from the A-A 'line. As shown in FIG. 3, the unnecessary polarization components reflected by the PBSs 115R and 115B travel in the direction along the z-axis in FIG. 3, respectively, and the unnecessary polarization components reflected by the PBS 115R enter the image sensor 130R. Unnecessary polarized light components reflected by the PBS 115B enter the image sensor 130B.

  By the way, the position adjustment mechanisms 140R, 140G, and 140B are mechanisms that allow the positions of the liquid crystal panels 120R, 120G, and 120B to be finely adjusted by the position adjustment mechanism control unit 152 in the position adjustment control device 150 of the light modulation element. In addition, as a drive part (actuator) of position adjustment mechanism 140R, 140G, 140B, it is desirable to use what can be finely moved by an electric signal like a piezoelectric element, for example, when performing highly accurate position adjustment.

  FIG. 4 is a view showing an example of the position adjusting mechanism. 4 shows the position adjustment mechanism 140R that adjusts the position of the liquid crystal panel 120R, the position adjustment mechanisms 140G and 140B that adjust the position of the other liquid crystal panels 120G and 120B also have the same configuration. ing.

  As shown in FIG. 4, the position adjusting mechanism 140R includes a frame body 141 provided so as to surround the liquid crystal panel 120R, and four positions interposed between each side of the frame body 141 and each side of the liquid crystal panel 120R. Piezoelectric elements 142 to 145 and four elastic members (for example, coil springs) 146 to 149 interposed between the sides of the frame body 141 and the sides of the liquid crystal panel 120R are provided. The four piezoelectric elements 142 to 145 and the four elastic members 146 to 149 are paired with piezoelectric elements and elastic members provided on opposite sides. That is, the piezoelectric element 142 and the elastic member 148, the piezoelectric element 143 and the elastic member 149, the piezoelectric element 144 and the elastic member 146, and the piezoelectric element 145 and the elastic member 147 form a pair.

  The piezoelectric element and the elastic member that make a pair are disposed at portions near the end portions of the opposing sides of the liquid crystal panel 120R. For example, taking a pair of the piezoelectric element 142 and the elastic member 148 as an example, the piezoelectric element 142 is provided near the upper end portion on the right side in the vertical direction of the liquid crystal panel 120R, and the elastic member 148 is provided on the left side in the vertical direction of the liquid crystal panel 120R. It is provided near the upper end of the side. Further, taking a pair of the piezoelectric element 143 and the elastic member 149 as an example, the piezoelectric element 143 is provided near the left end portion on the upper side in the horizontal direction of the liquid crystal panel 120R, and the elastic member 149 is provided on the lower side in the horizontal direction of the liquid crystal panel 120R. Provided near the left end of the side edge. Similarly, pairs of other piezoelectric elements and elastic members are also provided at portions near the end portions of the opposing sides of the liquid crystal panel 120R.

  By attaching the position adjustment mechanism 140R having such a configuration to the liquid crystal panel 120R as shown in FIG. 4, the liquid crystal panel 120R is placed in the horizontal direction (xx in FIG. 4 on a plane orthogonal to the optical axis of the R image light. It can be moved by a predetermined amount in the “direction” and the vertical direction (the yy ′ direction in FIG. 4). In addition to the horizontal and vertical movements of the liquid crystal panel 120R, the liquid crystal panel 120R is moved clockwise (θ direction in FIG. 4) and counterclockwise (FIG. 4) on a plane orthogonal to the optical axis of the R image light. Can also be rotated by a predetermined angle in the θ ′ direction).

  For example, the piezoelectric element 142 is driven so that a predetermined pressing force is applied to the liquid crystal panel 120R by the piezoelectric element 142, and the piezoelectric element 144 is driven so that a predetermined suction force is applied to the liquid crystal panel 120R by the piezoelectric element 144. By doing so, the liquid crystal panel 120R can be moved by a predetermined amount in the horizontal (left) direction (x ′ direction in FIG. 4).

  Further, the piezoelectric element 145 is driven so as to apply a predetermined pressing force to the liquid crystal panel 120R by the piezoelectric element 145, and at the same time, the piezoelectric element 143 is applied to the liquid crystal panel 120R by the piezoelectric element 143. By driving, the liquid crystal panel 120R can be moved by a predetermined amount in the vertical (upward) direction (y direction in FIG. 4).

  The four piezoelectric elements 142 to 145 are rotated by a predetermined angle by driving the four piezoelectric elements so that the same amount of pressing force or suction force is applied to the liquid crystal panel 120R. Can do. For example, when the piezoelectric elements 142 to 145 are driven so that the same amount of pressing force is applied to the liquid crystal panel 120R by the four piezoelectric elements 142 to 145, the liquid crystal panel 120R is counterclockwise (θ ′ direction). Conversely, if each of the piezoelectric elements 142 to 145 is driven so that the four piezoelectric elements 142 to 145 provide the same amount of suction force to the liquid crystal panel 120R, the liquid crystal panel 120R can be rotated. It can be rotated clockwise (θ direction).

  Although the position adjustment mechanism 140R corresponding to the liquid crystal panel 120R has been described with reference to FIG. 4, the same operation is possible for the position adjustment mechanisms 140G and 140B corresponding to the liquid crystal panels 120G and 120B.

Next, the image sensors 130R, 130G, and 130B will be described. The image sensors 130R, 130G, and 130B have a structure in which light detection elements such as a CCD or a CMOS are arranged in a matrix in the vertical direction and the horizontal direction, and an electric signal (analog signal) proportional to the amount of incident light. Output. An AD conversion circuit (not shown) that converts an analog signal into a digital signal is connected to the output side of each of the image sensors 130R, 130G, and 130B, and the image sensor output (image data) converted into a digital signal is This is input to the position adjustment control device 150 for the light modulation element. The image sensors 130R, 1
The resolution of 30G and 130B is preferably higher than the resolution of each liquid crystal panel 120R, 120G, and 120B.

  The image light of the unnecessary polarization component received by the image sensors 130R, 130G, and 130B is a negative image of each RGB image light incident on the cross dichroic prism 114. Accordingly, if the image light emitted from each of the liquid crystal panels 120R, 120G, and 120B is, for example, image light of a black image (minimum luminance image), the image sensors 130R, 130G, and 130B can display a white image (maximum luminance image). ).

  In general, the liquid crystal panels 120R, 120G, and 120B are regions that are not used for forming a projection image outside a pixel region (referred to as an effective pixel region) corresponding to a region (image formation region) for forming a projection image. It has a pixel area (referred to as a dummy pixel area) corresponding to (non-image forming area), and the projection image corresponding to the dummy pixel area is an image that is always displayed as a black image (image with the lowest luminance). It is common to be processed. For this reason, in the image sensors 130R, 130G, and 130B, the negative image corresponding to the dummy pixel region 122 is received as a white image (image with the maximum luminance).

  FIG. 5 is a diagram illustrating a dummy pixel region included in the liquid crystal panel. Although FIG. 5 shows the liquid crystal panel 120R, the same applies to the liquid crystal panels 120G and 120B. As shown in FIG. 5, the liquid crystal panel 120 </ b> R has a dummy pixel region 122 outside the effective pixel region 121.

  Since the dummy pixel region 122 is generally image-processed so that the projected image is always displayed as a black image (image with the lowest luminance), the dummy image area 122 is a dummy in the image sensors 130R, 130G, and 130B. The negative image corresponding to the pixel region 122 is received as a white image (maximum luminance image).

  FIG. 6 is a diagram illustrating an example of an image received by the image sensor. FIG. 6 shows an example of an image received by the image sensor 130R, but the same applies to the image sensors 130G and 130B.

  As shown in FIG. 6, the image received by the image sensor 130 </ b> R corresponds to an image 131 to be projected (referred to as a projection image) corresponding to the effective pixel area 121 of the liquid crystal panel 120 </ b> R and a dummy pixel area 122 outside the image. This is a white image 132. Furthermore, if the range in which the image sensor 130R can receive light can also receive the region outside the dummy pixel region 122 emitted from the liquid crystal panel 120R, there is no pixel outside the dummy pixel region 122 in the liquid crystal panel 120R. The black image 133 corresponding to the area is also received by the image sensor 130R.

  Although the image sensor 130R has been described in FIG. 6, the image sensors 130G and 130B also have a projection image 131 corresponding to the effective pixel area 121 of the liquid crystal panels 120G and 120B and a white image corresponding to the outer dummy pixel area 122, respectively. 132, and a black image 133 corresponding to an area where pixels outside the dummy pixel area do not exist.

  When the image sensors 130R, 130G, and 130B receive images (projected image 131, white image 132, and black image 133) as shown in FIG. 6, the image sensors 130R, 130G, and 130B receive the received images. Corresponding image data (image data after A / D conversion) is output, and the image data is respectively supplied to the position adjustment control device 150 of the light modulation element.

  The positional deviation calculation unit 151 in the position adjustment control device 150 of the light modulation element includes an image (white image) in the dummy pixel region 122 among the image data corresponding to the RGB images output from the image sensors 130R, 130G, and 130B. 132) is analyzed to detect the position of the edge of the dummy pixel region 122 (for example, the frame 122a outside the dummy pixel region 122) in each of the liquid crystal panels 120R, 120G, and 120B. The displacement direction and displacement amount of the panels 120R, 120G, and 120B are calculated. The detection of the outer frame 122a (referred to as the outer frame 122a) of the dummy pixel region 122 can be performed by using, for example, a known edge detection technique.

  Further, the displacement direction and displacement amount of each of the liquid crystal panels 120R, 120G, and 120B are dummy pixel regions obtained in a state where each of the liquid crystal panels 120R, 120G, and 120B is “reference position of each liquid crystal panel”. It can be obtained based on the position of the outer frame 122a of 122 and the position of the outer frame 122a of the dummy pixel region 122 obtained at the time of position adjustment.

  Here, the “reference position of each liquid crystal panel” means, for example, that the liquid crystal panels 120R, 120G, and 120B are adjusted so that there is no pixel shift between the liquid crystal panels in the adjustment stage before the shipment of the projector. The position of each liquid crystal panel 120R, 120G, 120B when placed is referred to as “reference position of each liquid crystal panel”. Of the image data corresponding to the RGB images output from the image sensors 130R, 130G, and 130B in a state where the liquid crystal panels 120R, 120G, and 120B are at “reference positions of the individual liquid crystal panels”. The image data corresponding to the RGB white image 132 is analyzed, the position of the outer frame 122a of the dummy pixel region 122 is calculated, and the position of the light modulation element is determined with the calculated position as the “reference position of each liquid crystal panel” The data is stored in the storage unit 153 in the adjustment control device 150.

  When the position is adjusted during actual use of the projector, image data corresponding to the RGB white image 132 out of image data corresponding to the RGB images output from the image sensors 130R, 130G, and 130B is used. The position shift calculation unit 151 in the light modulation element position adjustment control device 150 performs analysis to detect the position of the outer frame 122a of the dummy pixel region 122 (referred to as the outer frame position), and the detected outside of the dummy pixel region 122 is detected. From the frame position and the reference position of the liquid crystal panel stored in the storage unit 153, the positional deviation direction and the positional deviation amount of the liquid crystal panel are calculated.

  The position adjustment mechanism control unit 152 in the position adjustment control device 150 for the light modulation element should be corrected so as to correct the position shift direction and the position shift amount based on the position shift direction and the position shift amount thus calculated. The position adjustment mechanism corresponding to the liquid crystal panel is controlled to set the position of the liquid crystal panel to be corrected to a reference position.

  For example, the positional deviation of the liquid crystal panel 120R calculated by the positional deviation calculation unit 151 is d1 in the right direction (x direction) and the angle α1 in the clockwise direction (θ direction) in FIG. 4 with respect to the reference position of the liquid crystal panel 120R. If there is, the position adjustment mechanism control unit 152 adjusts the position adjustment mechanism corresponding to the liquid crystal panel 120R so that the position of the liquid crystal panel 120R becomes the reference position based on the calculated position displacement direction and amount of displacement. 140R is controlled. In this case, the position adjustment mechanism 140R rotates the liquid crystal panel 120R in the counterclockwise direction (θ ′ direction) in FIG. 4 by the angle α1 and moves it by d1 in the left direction (x ′ direction) in FIG. Thereby, the liquid crystal panel 120 can be returned to the reference position.

  By performing such position adjustment on all the liquid crystal panels in which the positional deviation occurs, it is possible to eliminate the deviation of the corresponding pixels of each of the liquid crystal panels 120R, 120G, and 120B.

  According to the projector according to the first embodiment, since the misregistration direction and the misregistration amount are calculated based on the white image 132 corresponding to the dummy pixel region 122, the misregistration direction and the misregistration amount are calculated. Without projecting a dedicated test image or the like, the misregistration direction and misregistration amount can be calculated during normal image projection. For this reason, the position adjustment control as described above can be performed in real time while the image is normally projected.

  In the projector according to the first embodiment, image light for adjusting the position (image light of unnecessary polarization components) is incident on the image light for projection (cross dichroic prism 114) by each PBS 115R, 115G, and 115B. Image light) is separated in a direction orthogonal to the optical path of the image light and incident on the image sensors 130R, 130G, and 130B. For this reason, since the image sensors 130R, 130G, and 130B are not installed at positions along the optical path of the image light for projection, the image light for projection is not blocked, and the image displayed on the projection surface is displayed. There is also an effect that there is no risk of adverse effects.

[Embodiment 2]
FIG. 7 is a diagram illustrating a configuration of the projector according to the second embodiment. The projector according to the second embodiment (referred to as projector PJ2) is different from the projector PJ1 according to the first embodiment shown in FIGS. 1 and 3 in that the optical path of the unnecessary polarization component reflected by the PBS 115R and the PBS 115B is the liquid crystal panel 120R. This is that the reflection directions of the PBSs 115R and 115B are set so as to be on the same plane as the optical path of the image light traveling from the liquid crystal panel 120B to the cross dichroic prism 114.

  By arranging the PBSs 115R and 115B so that the reflection directions of the PBSs 115R and 115B are as shown in FIG. 7, each image of the RB that advances from the liquid crystal panels 120R and 120B to the cross dichroic prism 114 by the image sensors 130R and 115B. It can arrange | position on the same plane as the optical path of light. In FIG. 7, the same components as those of the projector PJ1 according to the first embodiment shown in FIGS. 1 and 3 are denoted by the same reference numerals.

  In the projector PJ2 according to the second embodiment, similarly to the projector PJ1 according to the first embodiment, R image light and B image light are incident on the cross dichroic prism 114 with S polarization, and G image light is incident with P polarization. To do.

  In the projector PJ2 according to the second embodiment, by arranging the PBSs 115R and 115B so that the reflection directions of the PBSs 115R and 115B are as shown in FIG. 7, the R image light that passes through the PBS 115R and the B that passes through the PBS 115B. Each image light becomes P-polarized light. For this reason, in the projector PJ2 according to the second embodiment, 1 / 2λ plates 118R and 118B are provided between the PBSs 115R and 115B and the cross dichroic prism 114, respectively. Thereby, R image light and B image light can be incident on the cross dichroic prism 114 as S-polarized light. In the configuration of FIG. 7, the ½λ plate 113R and the ½λ plate 113B provided in the subsequent stage of the reflecting mirror 109 and the reflecting mirror 111 in FIGS. 1 and 3 are not necessary.

The projector PJ2 according to the second embodiment has a configuration as shown in FIG. 7, so that the P-polarized light transmitted through the PBS 115R is converted into S-polarized light by the 1 / 2λ plate 118R, and then enters the cross dichroic prism 114, and the PBS 115R The unnecessary polarized light component reflected by the light is incident on the image sensor 130R. Similarly, the P-polarized component transmitted through the PBS 115B is converted to S-polarized light by the 1 / 2λ plate 118B, and then incident on the cross dichroic prism 114, and the unnecessary polarized component reflected by the PBS 115B is converted into the image sensor 130B.
Is incident on.

  In addition, in the case of the G color image light emitted from the liquid crystal panel 120G, the P-polarized light transmitted through the PBS 115G is incident on the cross dichroic prism 114, and the unnecessary polarization component reflected by the PBS 115G is incident on the image sensor 130G, as in FIG. Is done. The position adjustment control of the liquid crystal panels 120R, 120G, and 120B based on the image data output from the image sensors 130R, 130G, and 130B can be performed in the same manner as the projector PJ1 according to the first embodiment. Omitted.

  In the projector PJ2 according to the second embodiment, the image sensors 130R and 130B are arranged on the same plane as the optical path of the image light to be projected, that is, the image sensors 130R and 130B are arranged on the same plane as the other optical system components. can do. For this reason, the projector PJ2 according to the second embodiment can reduce the size of the optical system of the projector in the thickness direction (z-axis direction in FIG. 7) compared to the projector PJ1 according to the first embodiment. Projector.

[Embodiment 3]
In the first and second embodiments, the light modulation element position adjustment control device 150 is incorporated in the projectors PJ1 and PJ2. However, the light modulation element position adjustment control device 150 is different from the projector. A projection system may be configured by the projector and the light modulation element position adjustment control device 150 provided as a constituent element.

  FIG. 8 is a diagram illustrating a configuration of a projection system according to the third embodiment. As shown in FIG. 8, the projection system according to the third embodiment includes a projector (projector PJ3), a light modulation element position adjustment control device 150, a projector PJ3, and a light modulation element position adjustment control device 150. And a cable 200 to be connected.

  The projector PJ3 has the same optical system as the projector PJ1 according to the first embodiment (see FIGS. 1 and 3), and the same components as those of the projector PJ1 according to the first embodiment are denoted by the same reference numerals. .

  Further, the light modulation element position adjustment control device 150 in the projection system shown in FIG. 8 is the light modulation element position adjustment control device 150 incorporated in the projector PJ1 (see FIG. 1) according to the first embodiment. A calculation unit 151, a position adjustment mechanism control unit 152, and a storage unit 153 are included. Also with the projection system configured as described above, the same position adjustment as that of the first embodiment can be performed. The light modulation element position adjustment control device 150 can be realized by providing an information processing device (such as a personal computer) with the function.

  In the projection system shown in FIG. 8, the projector PJ3 is exemplified as having the same optical system as the projector PJ1 according to the first embodiment (see FIGS. 1 and 3), but the projector PJ2 according to the second embodiment. Of course, the optical system of FIG. 7 may be used.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the image sensors 130R, 130G, and 130B are unnecessary polarization components of the entire image light (the entire image light including the entire dummy pixel region) emitted from the liquid crystal panels 120R, 120G, and 120B in each of the above-described embodiments. However, it is only necessary that the position of the outer frame 122a of the dummy pixel region 122 in each of the liquid crystal panels 120R, 120G, and 120B can be detected with high accuracy. Therefore, a configuration may be adopted in which photodetectors such as a CCD or a CMOS are arranged so that an unnecessary polarization component corresponding to only a specific portion of the dummy pixel region 122 in each of the liquid crystal panels 120R, 120G, and 120B can be detected.

  FIG. 9 is a diagram showing a modification of the image sensor. Although FIG. 9 shows the image sensor 130R, the other image sensors 130G and 130B can have the same configuration. The image sensor 130R shown in FIG. 9 has sensor regions S1 to S4 as regions corresponding to the periphery including the four “corner portions” of the dummy pixel region 122 as specific portions of the dummy pixel region 122 of the liquid crystal panel 120R. Photodetection elements such as CCD or CMOS are arranged only in the sensor regions S1 to S4. Note that the square grids in FIG. 9 represent individual photodetectors. Even with an image sensor configured as shown in FIG. 9, it is possible to detect the position of the outer frame 122a of the dummy pixel region 122 of the liquid crystal panel 120R with high accuracy.

  Further, the position adjustment mechanisms 140R, 140G, and 140B are movable in the vertical and horizontal directions on a plane orthogonal to the optical axis of the image light emitted from the liquid crystal panels 120R, 120G, and 120B in each of the above-described embodiments. In the plane, a mechanism that can rotate clockwise and counterclockwise about the optical axis of the image light as a rotation axis, in addition to the movement in the vertical and horizontal directions and the rotation in the clockwise and counterclockwise directions, Rotation at a predetermined angle with the axis of rotation (the x axis in FIG. 1) orthogonal to the optical axis of the image light (eg, the optical axis of the image light of the liquid crystal panel 120G in FIG. 1) Rotation at a predetermined angle with an axis perpendicular to the optical axis as a rotation axis (z axis in FIG. 1), a longitudinal direction along the optical axis of image light (y axis in FIG. 1) Can move It may be used as the mechanism, such as a.

  In each of the above-described embodiments, the RGB image light incident on the cross dichroic prism 114 is incident on S-polarized light for R image light and B image light, and P-polarized light for G image light. The same polarization component may be incident on all the RGB image lights.

  In the above-described embodiments, the black image negative image (white image 132) corresponding to the dummy pixel region 122 of each liquid crystal panel 120R, 120G, 120B is received by the image sensors 130R, 130G, 130B and received. Although the position of the outer frame 122a of the dummy pixel region 122 is detected based on the white image 132, when there is no dummy pixel region in each of the liquid crystal panels 120R, 120G, and 120B, the outermost effective pixel region is outside the effective pixel region. For example, one pixel can be used as a pixel area corresponding to the non-image forming area, that is, a dummy pixel area. In this case, display control is performed such that, for example, one pixel on the outermost side of the effective pixel region is displayed as a black image, and a negative image (white image) of one pixel is received by the image sensors 130R, 130G, and 130B. Then, the same position detection as that in each of the above-described embodiments is possible.

  In each of the above-described embodiments, unnecessary polarization components reflected by the respective PBSs 115R, 115G, and 115B have been shown to be directly incident on the image sensors 130R, 130G, and 130B (FIGS. 1, 3, and 7). For example, a lens for forming images of unnecessary polarization components on the image sensors 130R, 130G, and 130B may be interposed between the PBSs 115R, 115G, and 115B and the image sensors 130R, 130G, and 130B.

FIG. 3 is a diagram illustrating a configuration of a projector according to the first embodiment. FIG. 4 is a diagram showing a configuration of a general projector optical system in which R image light and B image light are incident on a cross dichroic prism with S polarization and G image light with P polarization. The figure seen from the A-A 'line in FIG. 1 in the arrow direction. The figure which shows an example of a position adjustment mechanism. 4A and 4B illustrate a dummy pixel region included in a liquid crystal panel. The figure which shows an example of the image acquired with an image sensor. FIG. 6 is a diagram illustrating a configuration of a projector according to a second embodiment. FIG. 6 is a diagram illustrating a configuration of a projection system according to a third embodiment. The figure which shows the modification of an image sensor.

Explanation of symbols

  112R, 112G, 112B ... Polarizing plate, 113R, 113G, 113B ... 1 / 2λ plate, 114 ... Cross dichroic prism, 115R, 115G, 115B ... PBS (polarization separating means), 117R, 117G , 117B ... polarizing plate, 118R, 118B ... 1 / 2λ plate, 120R, 120G, 120B ... liquid crystal panel (light modulation element), 121 ... effective pixel area, 122 ... dummy pixel area , 130R, 130G, 130B ... image sensor, 131 ... projected image, 132 ... white image, 133 ... black image, 140R, 140G, 140B ... position adjustment mechanism, 141 ... frame Body, 142 to 145... Driving unit (piezoelectric element), 146 to 149... Elastic member, 150. , 151... Position deviation calculation unit, 152... Position adjustment mechanism control unit, 153.

Claims (10)

A projector having a plurality of light modulation elements corresponding to different color components, and a combining optical system for combining the image lights emitted from the light modulation elements of the plurality of light modulation elements,
Polarization separation means for separating unnecessary polarization components unnecessary for projection among the polarization components of each image light emitted from each of the light modulation elements;
An image sensor that receives the separated unnecessary polarization component and outputs image data corresponding to the received unnecessary polarization component;
A position adjustment mechanism capable of adjusting the position of each light modulation element for each light modulation element;
A position shift calculation unit that calculates a position shift direction and a position shift amount of each light modulation element based on image data output from the image sensor, and a position shift direction and a position shift amount calculated by the position shift calculation unit. A position adjustment control device for a light modulation element having a position adjustment mechanism control unit for controlling the position adjustment mechanism based on the above;
A projector comprising: The projector according to claim 1, wherein
The projector according to claim 1, wherein the polarization separation means is provided between each of the light modulation elements and the combining optical system. The projector according to claim 1 or 2,
The projector according to claim 1, wherein the polarization separation unit separates the unnecessary polarization component in a direction orthogonal to an optical axis of image light output from each light modulation element. The projector according to any one of claims 1 to 3,
The misregistration calculation unit includes an edge of the non-image forming area from image data corresponding to a non-image forming area existing outside the image forming area of each light modulation element among the image data output from the image sensor. A projector that detects a position and calculates the position shift direction and the position shift amount based on the detected edge position. The projector according to claim 4, wherein
The edge position of the non-image forming region when each light modulation element is set to a reference position with no positional deviation is calculated in advance as a reference position of each light modulation element,
The misregistration calculation unit is configured to detect the light at the current time based on an edge position of the non-image forming region obtained based on image data output from the image sensor at a current time and a reference position of each light modulation element. Calculate the displacement direction and displacement amount of the modulation element,
The projector according to claim 1, wherein the position adjustment mechanism control unit controls the position adjustment mechanism so as to correct the calculated displacement direction and displacement amount. The projector according to claim 4 or 5,
The projector according to claim 1, wherein the image sensor includes a light detection element so as to be able to receive an unnecessary polarization component in a region including the entire non-image forming region. The projector according to claim 4 or 5,
The projector according to claim 1, wherein the image sensor is provided with a light detection element so as to be able to receive an unnecessary polarization component in a specific portion of the non-image forming region. In the projector according to any one of claims 1 to 7,
The position adjusting mechanism enables movement of the light modulation element in the vertical direction and the horizontal direction on a plane orthogonal to the optical axis of the image light output from each light modulation element, and the image light on the plane. A projector having a mechanism that enables rotation of the light modulation element in a clockwise direction and a counterclockwise direction around the optical axis of the light. A projector having a plurality of light modulation elements corresponding to different color components, a combining optical system for combining the image lights emitted from the light modulation elements of the plurality of light modulation elements, and A projection system having a position adjustment control device for a light modulation element that performs position adjustment control,
The projector is
Polarization separation means for separating unnecessary polarization components unnecessary for projection among the polarization components of each image light emitted from each of the light modulation elements;
An image sensor that receives the separated unnecessary polarization component and outputs image data corresponding to the received unnecessary polarization component;
A position adjustment mechanism capable of adjusting the position of each light modulation element for each light modulation element;
Have
The position adjustment control device of the light modulation element,
A displacement calculation unit that calculates a displacement direction and a displacement amount of each light modulation element based on image data output from the image sensor;
A position adjustment mechanism control unit that controls the position adjustment mechanism based on a position shift direction and a position shift amount calculated by the position shift calculation unit;
A projection system comprising: A plurality of light modulation elements corresponding to different color components, a combining optical system for combining the image lights emitted from the light modulation elements of the plurality of light modulation elements, and the light emitted from the light modulation elements A polarization separator that separates unnecessary polarization components that are unnecessary for projection out of polarization components of image light; an image sensor that receives the separated unnecessary polarization components and outputs image data corresponding to the received unnecessary polarization components; A position adjusting method for adjusting the position of each light modulation element in a projector having a position adjustment mechanism capable of adjusting the position of each light modulation element for each light modulation element,
Calculating a displacement direction and a displacement amount of each light modulation element based on image data output from the image sensor;
Controlling the position adjustment mechanism based on the calculated displacement direction and displacement amount;
A method for adjusting the position of a light modulation element, comprising: