JP2011164246A - Detection device of amount of projection position deviation, detection method of amount of projection position deviation, and projection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for detecting projection position deviation of images superimposed on a screen while projecting the images. <P>SOLUTION: This detection device of the projection position deviation detects projection position deviation of a first image and a second image while the first image having a first polarizing component and the second image having a second polarizing component are superimposed on a screen SCR. This detection device includes a superimposed image separation part 100 for separating the first image and the second image projected while being superimposed on the screen SCR into the first image having the first polarizing component and the second image having the second polarizing component based on difference in polarizing components, an imaging device 121 for imaging the first image and the second image being separated from each other in the superimposed image separation part 100 and outputting imaged image data corresponding to the first image and imaged image data corresponding to the second image, and a computing part 130 for computing amount of deviation of projection positions of the first image and the second image based on the imaged image data corresponding to the first image and the imaged image data corresponding to the second image. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a projection displacement detection device, a projection displacement detection method, and a projection system.

In recent years, a projector in which two light modulation element units (referred to as a first light modulation element unit and a second light modulation element unit) are incorporated is known. These first light modulation element unit and second light modulation element unit are respectively red light (R), green light (G) and blue light (B
), And a cross dichroic prism that synthesizes each color light of RGB emitted from each of the light modulation elements. In some cases, the RGB light modulation elements and the cross dichroic prism may be integrated.

A first image synthesized by the cross dichroic prism is emitted from the first light modulation element unit, and a second image synthesized by the cross dichroic prism is emitted from the second light modulation element unit. Note that the first image emitted from the first light modulation element unit and the second image emitted from the second light modulation element unit generally have different polarization components. That is, if the first image has a first polarization component (for example, a p-polarization component), the second image has a second polarization component (for example, an s-polarization component). The first image and the second image are combined by the polarization combining optical system, and then projected onto the screen as the projection plane by the projection optical system.

In such a projector, high brightness is achieved by matching the corresponding pixels of the first image emitted from the first light modulation element unit and the second image emitted from the second light modulation element unit with high accuracy. It is possible to display a high-resolution image on the screen by performing projection by “diagonal pixel shift” in which each corresponding pixel is shifted by 1/2 pixel in the diagonal direction. Can do.

In either case, in order to display a high-quality image on the screen, the first
The first light modulation element unit and the second light modulation element unit are arranged such that the positional relationship between the corresponding light modulation elements of the light modulation element unit and the respective light modulation elements of the second light modulation element unit is appropriately adjusted. It is necessary to adjust the light modulation element unit with high accuracy.

A projection system that performs stacking projection with two projectors is also known. In this case, it is assumed that one light modulation element unit is incorporated in each of the two projectors (referred to as a first projector and a second projector). That is, the first projector incorporates the first light modulation element unit, and the second projector
It is assumed that the second light modulation element unit is incorporated in the projector.

Then, an image emitted from the first light modulation element unit of the first projector (referred to as a first image) is projected on the screen by the projection optical system of the projector, and from the second light modulation element unit of the second projector. The emitted image (referred to as the second image) is projected on the screen by the projection optical system of the projector. In the case of stacking projection, the first image and the second image are projected in a state of being superimposed on the screen.

Also in such a projection system, the projection positions of the first image emitted from the first light modulation element unit of the first projector and the second image emitted from the second light modulation element unit of the second projector can be accurately determined. It is important to adjust.

As described above, when a high-luminance or high-resolution image is displayed on the screen by a projector incorporating two light modulation element units, or when stacking projection is performed by two projectors, the first on the screen is used. Adjustment of the projection positions of the image and the second image is essential.

In order to adjust the projection position, it is important to obtain the projection position deviation amount between the first image and the second image displayed in a superimposed state with high accuracy. In order to acquire the projection position deviation amount between the first image and the second image with high accuracy, first, the first image displayed in the superimposed state and the second image are displayed.
Although it is necessary to acquire the projection position deviation amount between the first image and the second image with high accuracy after identifying the image, various techniques have been proposed in the past (for example, Patent Documents). 1)
.

In the technique disclosed in Patent Document 1 (hereinafter referred to as the conventional technique), images projected from two projectors (a first projector and a second projector) (referred to as a first image and a second image) are polarized light combining optics. After being synthesized by the system, it is projected on the screen by the projection optical system. In addition, an imaging device (video camera) is installed so that leakage light from the polarization combining optical system is incident.

In addition, the conventional technology projects test patterns having different patterns from the first projector and the second projector in order to distinguish the first image and the second image from the images displayed in a superimposed state. I am doing so. That is, the first test pattern is projected on the screen from the first projector, the second test pattern is projected on the screen from the second projector, and the first test pattern and the second test pattern projected on the screen are displayed. Take an image with an imaging device. Then, the position detection processing unit detects the feature point coordinates of the first test pattern and the second test pattern based on the captured image data output from the video camera, and calculates the positional deviation correction amount based on the detection result. .

JP 2005-277931 A

According to the above-described conventional technology, the first image projected by the first projector and the second image projected by the second projector can be distinguished from the first image and the second image projected in a state of being superimposed on the screen. Therefore, it is necessary to project different test patterns (first test pattern and second test pattern) from the corresponding projectors.

For this reason, for example, when it becomes necessary to adjust the position during projection of a normal image such as a movie, the projection of the normal image is interrupted, and the first test pattern is generated from the first projector. And projecting a second test pattern from the second projector, calculating a displacement amount based on the first test pattern and the second test pattern, and correcting the projection position based on the calculation result. After the operation is performed, it is necessary to perform an operation such as resuming normal image projection again. As described above, it is inefficient to perform such a position adjustment operation every time position adjustment is performed, and it is not preferable to interrupt normal image projection.

Therefore, the present invention provides a projection position deviation amount detection device capable of detecting a projection position deviation amount of an image projected in a state of being superimposed on a screen during normal image projection without displaying a test pattern, An object of the present invention is to provide a projection position deviation detection method and a projection system.

In the projection position shift amount detection device of the present invention, the first image when the first image having the first polarization component and the second image having the second polarization component are projected in a state of being superimposed on the projection surface. A projection position deviation amount detection device for detecting a projection position deviation amount between an image and the second image, the first image and the second image being projected in a state of being superimposed on the projection plane, A superimposed image separation unit that separates based on a difference in polarization components, the first image and the second image separated by the superimposed image separation unit, and imaged image data corresponding to the first image, An imaging device that outputs captured image data corresponding to the second image, captured image data corresponding to the first image, and captured image data corresponding to the second image, the first image and the second image, Projection position for calculating the amount of projection position deviation And having a shift amount calculating section.

As described above, according to the present invention, images with different polarization components projected in a state of being superimposed on the projection surface (for example, a first image having a p-polarization component and a second image having an s-polarization component) are different in polarization component. The projection position deviation amount is calculated based on the captured image data. As a result, it is possible to detect the amount of projection position deviation of an image projected in a state of being superimposed on the projection surface during projection of a normal image without displaying a test pattern.

In the projection position shift amount detection apparatus of the present invention, the superimposed image separation unit includes a first polarization component transmission region that transmits the first polarization component and a second polarization component transmission region that transmits the second polarization component. A composite polarizing plate formed on one polarizing plate is preferable.

By using such a composite polarizing plate, the first image having the first polarization component and the second image can be obtained.
A second image having a polarization component can be simultaneously imaged by one polarizing plate (composite polarizing plate) and one imaging device.

In the projection position shift amount detection device of the present invention, it is preferable that the first polarization component transmission region and the second polarization component transmission region are alternately formed in a strip shape on the polarizing plate.

Since the composite polarizing plate has such a configuration, the first image and the second image are based on an image of a line (such as an edge portion of the image) that crosses the first polarization component transmission region and the second polarization component transmission region.
The amount of projection position deviation from the image can be detected appropriately and easily.

In the projection position shift amount detection device of the present invention, the first polarization component transmission region and the second polarization component transmission region are divided into one region and the other region when the polarizing plate is divided into two regions. It is also preferred that it is formed.

Even if the composite polarizing plate has such a configuration, the first polarization component transmission region and the second
Based on a line image (such as an edge portion of the image) that crosses the polarization component transmission region, it is possible to appropriately and easily detect the projection position shift amount between the first image and the second image.

In the projection position shift amount detection device of the present invention, the superimposed image separation unit includes a first polarization component transmission polarizer that transmits the first polarization component or a second polarization component transmission polarizer that transmits the second polarization component. It is also preferable that the first polarizing component transmission polarizing plate or the second polarizing component transmission polarizing plate is installed so as to be capable of rotating by 90 degrees.

This uses a polarizing plate of either a first polarizing component transmission polarizing plate (for example, a p-polarization component transmission polarizing plate) or a second polarizing component transmission polarizing plate (for example, an s-polarization component transmission polarizing plate).
A first image and a second polarization component having a first polarization component (for example, a p-polarization component) in one polarizing plate by installing the polarization component transmission polarization plate or the second polarization component transmission polarization plate so as to be rotatable by 90 degrees. A second image having (for example, an s-polarized component) can be captured by a single imaging device. Note that in this case, from the captured image data output from the imaging device, the vertical direction and the horizontal direction are used regardless of whether the first polarizing component transmission polarizing plate or the second polarization component transmission polarizing plate is used. A line image (such as an edge portion of the image) extending in the direction can be detected. Therefore, it is possible to calculate the vertical projection position deviation amount and the horizontal projection position deviation amount.

In the projection position shift amount detection apparatus of the present invention, the superimposed image separation unit includes a first polarization component transmission polarizer that transmits the first polarization component and a second polarization component transmission polarizer that transmits the second polarization component. It is also preferable that these two polarizing plates are used.

This uses both the first polarizing component transmission polarizing plate (for example, p-polarization component transmission polarizing plate) and the second polarizing component transmission polarizing plate (for example, s-polarization component transmission polarizing plate). Thus, by using both the first polarization component transmission polarizing plate and the second polarization component transmission polarization plate, for example, by preparing an imaging device corresponding to each polarization plate, the first polarization component transmission p-polarization component is provided. One image and a second image having an s-polarized component can be captured simultaneously. In addition, also when using both such a 1st polarization component transmission polarizing plate and a 2nd polarization component transmission polarizing plate, from the picked-up image data output from an imaging device, the line image (image) extended in the vertical direction and a horizontal direction Can be detected. Therefore, it is possible to calculate the vertical projection position deviation amount and the horizontal projection position deviation amount.

In the projection position shift amount detection device of the present invention, the superimposed image separation unit includes a first polarization component transmission polarizer that transmits the first polarization component or a second polarization component transmission polarizer that transmits the second polarization component. The first image and the second image are separated by using any one of the polarizing plates and a TN (Twisted Nematic) type liquid crystal in combination and controlling the application of the driving voltage to the TN type liquid crystal. It is also preferred that it be permeable.

Even with such a configuration, it is possible to separate and image the images (first image and second image) projected in a state of being superimposed on the projection surface due to the difference in polarization components. In this case, only one imaging device is required, and the polarization component that can be transmitted can be switched only by voltage application control to the TN liquid crystal, so that the polarizing plate is rotated or slid. This mechanism becomes unnecessary.

In the projection misregistration amount detection device of the present invention, the projection misregistration amount calculation unit includes the first image and the second image based on the captured image data corresponding to the first image and the captured image data corresponding to the second image. It is preferable to detect an edge portion common to the image and calculate a relative projection position shift amount between the first image and the second image at the detected edge portion.

Since the edge portion of the image is detected in this way and the relative shift amount between the positions of the first image and the second image at the detected edge portion is calculated, a normal image can be obtained without using a test pattern. Can be used to calculate the amount of deviation of the projection position.

In the projection position deviation amount detection apparatus of the present invention, the relative projection position deviation amount with respect to the first image and the second image is determined by the light modulation element of the first light modulation element unit that emits the first image and the first image. It is preferable to calculate the pixel shift amount of the corresponding pixel of the light modulation element of the second light modulation element unit that emits the second image.

As described above, the projection position deviation amount is calculated as the pixel deviation amount of the pixel corresponding to each of the light modulation element of the first light modulation element unit and the light modulation element of the second light modulation element unit, thereby correcting the projection position. In the case of performing the correction, the projection position can be corrected based on the calculated pixel shift amount, so that an appropriate projection position can be corrected.

In the projection position shift amount detection method of the present invention, the first image when the first image having the first polarization component and the second image having the second polarization component are projected in a state of being superimposed on the projection plane. A projection position deviation amount detection method for detecting a projection position deviation amount between an image and the second image, the first image and the second image being projected in a state of being superimposed on the projection plane, Separating based on a difference in polarization components, capturing the first image and the second image separated by the superimposed image separation unit, and capturing image data corresponding to the first image and the second image A step of outputting captured image data corresponding to the first image, and a projection position shift between the first image and the second image based on the captured image data corresponding to the first image and the captured image data corresponding to the second image. Calculating the quantity Characterized in that it.

According to the projection position shift amount detection method of the present invention, the same effect as the projection position shift amount detection apparatus of the present invention can be obtained. Note that the projection position deviation amount detection method of the present invention preferably has the characteristics of the projection position deviation amount detection apparatus of the present invention.

In the projection system of the present invention, the first light modulation element unit that projects the first image having the first polarization component onto the projection surface, and the second image having the second polarization component are superimposed on the first image. The second light modulation element unit that projects on the projection surface, the superimposed image separation unit that separates the first image and the second image based on the difference in polarization components, and the superimposed image separation unit. An imaging device that captures the first image and the second image and outputs captured image data corresponding to the first image and captured image data corresponding to the second image; and corresponding to the first image A projection position deviation amount calculation unit that calculates a projection position deviation amount between the first image and the second image based on the captured image data and the captured image data corresponding to the second image.

According to the projection system of the present invention, when the first image and the second image are projected on the projection surface, the image projected on the projection surface is superimposed. Can be separated and imaged by the difference in polarization components. Then, the projection position deviation amount can be calculated based on the captured image data obtained by imaging. As a result, it is possible to detect the amount of projection position deviation of an image projected in a state of being superimposed on the projection plane during normal image projection without displaying a test pattern. In the projection system of the present invention, it is preferable that the projection system includes the features of the projection position deviation amount detection apparatus of the present invention.

In the projection system of the present invention, a polarization combining optical system that combines the first image and the second image, and the first image and the second image combined by the polarization combining optical system are placed on the projection plane. A projection optical system for projecting, the first light modulation element unit, the second
It is preferable that the light modulation element unit, the polarization combining optical system, and the projection optical system are provided in one projector.

This is one projector that incorporates two light modulation element units.
The first image having the first polarization component emitted from the first light modulation element unit and the second image having the second polarization component emitted from the second light modulation element unit are displayed in a state of being superimposed on the projection plane. Is. Even in such a projection system, it is possible to detect the amount of projection position deviation of an image projected in a state of being superimposed on the projection surface during projection of a normal image without displaying a test pattern.

In the projection system of the present invention, a first projector including a first projection optical system that projects the first light modulation element unit and a first image emitted from the first light modulation element unit onto the projection plane; A second projection optical system that projects the second light modulation element unit and a second image emitted from the second light modulation element unit onto the projection plane;
It is preferable to have a projector.

This uses two projectors to display a first image emitted from the first light modulation element unit of the first projector and a second image emitted from the second light modulation element unit of the second projector on the projection plane. It is displayed in a state of being superimposed on. Even in such a projection system, it is possible to detect the amount of projection position deviation of an image projected in a state of being superimposed on the projection surface during projection of a normal image without displaying a test pattern.

In the projection system of the present invention, the first image emitted from the first light modulation element unit and the second light modulation element unit are emitted based on the projection position deviation amount calculated by the projection position deviation amount calculation unit. It is preferable to further include a projection position correction device that corrects the projection position of the second image to be corrected.

By having such a projection position correction apparatus, it is possible to correct a shift in the projection position of the first image of the first light modulation element unit and the second image of the second light modulation element unit, and to project the projected image. It can be of high quality.

1 is a diagram illustrating a configuration of a projection system 10 according to a first embodiment. The figure which shows the structural example of the composite polarizing plate 111 typically. FIG. 2 is a plan view schematically showing the configuration of the optical device of the projector PJ1 according to the first embodiment. The flowchart explaining the whole process sequence of a projection position shift amount detection apparatus. FIG. 6 is a diagram schematically illustrating a correspondence relationship between an imaging result obtained by the imaging apparatus 121 and a composite polarizing plate 111. The figure which shows typically the actual imaging result of the 1st image G1 which permeate | transmitted the composite polarizing plate 111, and the 2nd image G2. FIG. 4 is a diagram illustrating a configuration of a projection system 20 according to a second embodiment. FIG. 5 is a diagram illustrating a configuration of a projection system 30 according to a third embodiment. FIG. 6 is a diagram illustrating a configuration of a projection system 40 according to a fourth embodiment. FIG. 10 is a diagram illustrating a configuration of a projection system 50 according to a fifth embodiment.

  Hereinafter, embodiments of the present invention will be described.

[Embodiment 1]
FIG. 1 is a diagram illustrating a configuration of a projection system 10 according to the first embodiment. The projection system 10 according to the first embodiment includes a projector PJ, a projection position deviation amount detection device 100, and a projection position correction device 200.

The projector PJ uses a first light modulation element unit 400A (see FIG. 3) that emits a first image G1 having a first polarization component (referred to as a p-polarization component), and a second polarization component (referred to as an s-polarization component). And a second light modulation element unit 400B (see FIG. 3) that emits the second image G2 having the second image G2. The projection misregistration amount detection device 100 includes a screen S for the first image G1 and the second image G2.
A deviation amount of the projection position on the CR (referred to as a projection position deviation amount) is detected. In addition, the projection position correction apparatus 200 corrects the projection position based on the projection position deviation amount detected by the projection position deviation amount detection apparatus 100.

Note that the first image G1 having the p-polarized component and the second image G2 having the s-polarized component are projected on the screen SCR, and thus the screen SC.
Here, the first image G1 and the second image G2 projected in a state of being superimposed on R will be referred to as superimposed images here.

The projection position deviation amount detection apparatus 100 converts the superimposed image into the first image G1 based on the difference in polarization components.
And the second image G2, a superimposition image separation unit 110, an imaging device 121 that captures the first image G1 and the second image G2 separated by the superimposition image separation unit 110 and outputs captured image data, and imaging A projection position deviation amount calculation unit 130 that calculates the projection position deviation amount between the first image G1 and the second image G2 based on the image data.

The superimposed image separation unit 110 is arranged on the front side of the imaging lens (screen S in the imaging device 121).
Provided on the CR side) and has a function of separating the superimposed image into a first image G1 having a p-polarized component and a second image G2 having an s-polarized component.

The superimposed image separation unit 110 in the projection system 10 according to the first embodiment includes a first polarization component transmission region that transmits a p-polarized component (referred to as a p-polarization component transmission region) and a second polarization component transmission region that transmits an s-polarization component. A polarizing plate is used which is formed on a single polarizing plate (referred to as an s-polarized component transmission region). Such a polarizing plate is referred to as a composite polarizing plate 111. Further, it is assumed that the composite polarizing plate 111 has a structure capable of transmitting the p-polarized component and the s-polarized component alternately for each predetermined region. The configuration of the composite polarizing plate 111 will be described later.

The imaging device 121 has a resolution sufficiently higher than the resolution of the light modulation element of the projector PJ, and is set to perform imaging at a magnification such that at least one pixel of the projector PJ can be recognized. To do. Further, in FIG. 1, the imaging device 121 is illustrated using an imaging device prepared separately from the projector PJ, but an imaging device mounted on the projector PJ can also be used.

FIG. 2 is a diagram schematically illustrating a configuration example of the composite polarizing plate 111. As illustrated in FIG. 2, the composite polarizing plate 111 used in the projection system 10 according to the first embodiment includes a plurality of p-polarized component transmission regions and a plurality of s-polarized component transmission regions. Here, each of the p-polarized component transmissive region and the s-polarized component transmissive region has a strip shape in which one direction (X direction) is the longitudinal direction. Further, the p-polarized component transmissive regions and the s-polarized component transmissive regions are alternately formed along a direction (Y direction) orthogonal to the longitudinal direction.

The p-polarized component transmission region transmits light having the p-polarized component, and the s-polarized component transmission region transmits light having the s-polarized component. Thus, the first image G1 having the p-polarized component emitted from the first light modulation element unit 400A transmits the p-polarized component transmission region and has the s-polarized component emitted from the second light modulation element unit 400B. The second image G2 is transmitted through the s-polarized component transmission region.

The imaging device 121 is installed so that a superimposed image can be captured. Since the composite polarizing plate 111 as shown in FIG. 2 is installed in front of the imaging lens in the imaging device 121, the captured image data captured by the imaging device 121 includes p of the composite polarizing plate 111.
Captured image data corresponding to the first image G1 that is transmitted through the polarization component transmission region and captured image data corresponding to the second image G2 that is transmitted through the s-polarization component transmission region are included.

FIG. 3 is a plan view schematically showing the configuration of the projector PJ according to the first embodiment. As shown in FIG. 3, the projector PJ according to the first embodiment includes a light source 300 that emits light including RGB, an integrator optical system 310, a first light modulation element unit 400 </ b> A, and a second light modulator 300 </ b> A.
The light modulation element unit 400B, the polarization separation mirror 320, and the first color separation guide that separates the light having the p-polarized component separated by the polarization separation mirror 320 into RGB color lights and guides them to the first light modulation element unit 400A. The light having the s-polarized component separated by the optical optical system 500A and the polarization separation mirror 320 is separated into RGB color light, and the second light modulation element unit 400B.
The second color separation light guiding optical system 500B guided to the light, and the polarization combining prism 80 as the polarization combining optical system.
0 and a projection optical system 600 that enlarges and projects the image synthesized by the polarization synthesis prism 800 onto the screen SCR.

The first light modulation element unit 400A includes light modulation elements 410R and 4 corresponding to RGB colors.
10G, 410B and a cross dichroic prism 420, and the light modulation elements 410R, 410G, 410B and the cross dichroic prism 420 are integrated. Note that an incident-side polarizing plate is provided on the incident side of the light modulation elements 410R, 410G, and 410B, and an emission-side polarizing plate is provided on the emission side, but these symbols are omitted. A first image G1 having a p-polarized component is emitted from the first light modulation element unit 400A configured as described above.

On the other hand, the second light modulation element unit 400B includes light modulation elements 411 corresponding to RGB colors.
R, 411G, 411B and a cross dichroic prism 421 are provided, and the light modulation elements 411R, 411G, 411B and the cross dichroic prism 421 are integrated. In addition, the incident side polarizing plate is provided on the incident side of the light modulation elements 411R, 411G, and 411B, and the emission side polarizing plate is provided on the emission side, but these symbols are omitted. From the second light modulation element unit 400B configured in this way,
A second image G2 having an s-polarized component is emitted.

In addition, the first color separation light guide optical system 500A reflects red light (R) out of light having a p-polarized component that has passed through the polarization separation mirror 320, and emits green light (G) and blue light (B). The dichroic mirror 510 that passes through, the dichroic mirror 520 that reflects green light out of the green light and blue light that passes through the dichroic mirror 510, and the blue light that passes through the dichroic mirror 520, and the light modulation element 410B. Two relay lenses 530 and 540 and two reflecting mirrors 550 and 560 leading to the dichroic mirror 51
A reflection mirror 570 for guiding the red light reflected at 0 to the light modulation element 410R. In this case, since the reflection mirror 570 is shared with the second color separation light guide optical system 500B, a double-sided reflection mirror is used.

On the other hand, the second color separation light guide optical system 500B reflects red light (R) out of the light having the s-polarized component reflected by the polarization separation mirror 320, and green light (G) and blue light (B). A dichroic mirror 511 that passes the dichroic mirror, a dichroic mirror 521 that reflects the green light out of the green light and blue light that has passed through the dichroic mirror 511, and passes the blue light,
It has two relay lenses 531 and 541 and two reflection mirrors 551 and 561 for guiding the blue light that has passed through the dichroic mirror 521 to the light modulation element 411B. The red light reflected by the dichroic mirror 511 is reflected by the double-sided reflection mirror 570 shared with the first light modulation element unit 400B and enters the light modulation element 411R.

The polarization combining prism 800 includes a first image G1 having a p-polarized component emitted from the first light modulation element unit 400A and a second image G2 having an s-polarized component emitted from the second light modulation element unit 400B. Synthesize. Then, the image synthesized by the polarization synthesis prism 800 is enlarged by the projection optical system 600 and projected onto the screen SCR.

By the way, the projector PJ matches the corresponding pixels of the first image emitted from the first light modulation element unit 400A and the second image emitted from the second light modulation element unit 400B with high accuracy, so that In addition to being able to display a luminance image on the screen SCR, it is possible to project a high-resolution image on the screen SCR by performing projection by “diagonal pixel shift” in which the corresponding pixels are shifted by 1/2 pixel in the diagonal direction. Can be displayed.

In any case, each light modulation element 410R, 410G of the first light modulation element unit 400A.
410B and the second light modulation element unit 400B, the light modulation elements 411R, 411G, 4
It is necessary to adjust the position of the first light modulation element unit 400A and the second light modulation element unit 400B with high accuracy so that the positional relationship between the corresponding pixels of 11B is appropriately adjusted.

In addition, each light modulation element 410A, 410G, 410B of the first light modulation element unit 400A.
The cross dichroic prism 420 and the like have an integrated structure, and their positional relationship is fixed, and similarly, each light modulation element 4 of the second light modulation element unit 400B.
11A, 411G, 411B, the cross dichroic prism 421, and the like have an integrated structure, and their positional relationship is fixed.

FIG. 4 is a flowchart illustrating an overall processing procedure of the projection position deviation amount detection apparatus. As shown in FIG. 4, first, the superimposed image is separated into the first image G2 having the first polarization component and the second image G2 having the second polarization component by the composite polarizing plate 111 (step S1). The imaging device 121 captures the first image G1 and the second image G2, and outputs captured image data corresponding to the first image G1 and captured image data corresponding to the second image G2 (step S2).
). Then, based on the captured image data corresponding to the first image G1 and the captured image data corresponding to the second image G2, the projection positional deviation amount calculation unit 130 calculates the projection positional deviation amount between the first image G1 and the second image G2. Calculate (step S3).

In addition, the process which calculates the projection position shift amount of the 1st image G1 and the 2nd image G2 in step S3 specifically, 1st light modulation element unit 400A and 2nd light modulation element unit 4
Relative displacement of the second light modulation element unit 400B with respect to the first light modulation element unit 400A serving as a reference, based on one light modulation element unit of 00B (here, referred to as the first light modulation element unit 400A) It is assumed that this is a process for calculating an amount. The same applies to other embodiments described later.

First, the projection position deviation amount calculation unit 130 calculates an edge portion common to the first image G1 and the second image G2 from the captured image data corresponding to the first image G1 and the captured image data corresponding to the second image G2. To detect. At this time, an optimum edge portion is detected when calculating the projection position deviation amount. In this case, the p-polarized component transmissive region and the s-polarized component transmissive region of the composite polarizing plate 111 are formed in a band shape in the vertical direction (X direction), and thus cross the p-polarized component transmissive region and the s-polarized component transmissive region. It is preferable to detect such an edge portion extending in the lateral direction (Y direction).

Then, when the optimum edge portion is detected, the detected edge portion is used as a target edge, and a relative projection position shift amount between the first image G1 and the second image G2 at the target edge is calculated. Specifically, the relative projection displacement between the first image G1 and the second image G2 is one light modulation element having the first light modulation element unit 400A and one having the second light modulation element unit 400B. It is calculated as a shift amount of pixels corresponding to each of the two light modulation elements (referred to as a pixel shift amount).

Note that one light modulation element having the light modulation element unit 400A and one light modulation element having the second light modulation element unit 400B are the green light modulation element 410G and the first light modulation element 410G in the first light modulation element unit 400A. It is assumed that the light modulation element 411G for green in the two-light modulation element unit 400B. The same applies to other embodiments described later.

The first light modulation element unit 400A includes light modulation elements 4 corresponding to RGB.
10R, 410G, 410B exist, and the second light modulation element unit 400B has light modulation elements 411R, 411G, 411B corresponding to RGB, but as described above, the light modulation elements 410R, 410G, 410B. And the light modulation element 410R.
, 410G and 410B are set appropriately, and the positional relationship is fixed.

Therefore, the relative pixel shift amount of the green light modulation element 411G of the second light modulation element unit 400B with respect to the green light modulation element 410G of the first light modulation element unit 400A is
This represents a relative pixel shift amount of each of the light modulation elements 411R, 411G, and 411B of the second light modulation element unit 400B with respect to each of the light modulation elements 410R, 410G, and 410B of the first light modulation element unit 400A.

When the relative projection position deviation amount between the first image G1 and the second image G2 is calculated by the projection position deviation amount calculation processing procedure shown in FIG. 4, the projection position correction apparatus 200 calculates the calculated relative projection position. Based on the shift amount, the image data is corrected so that the first image G1 and the second image G2 have an appropriate positional relationship. Here, since the first light modulation element unit 400A is used as a reference, the projection position is corrected on the second light modulation element unit 400B side.

FIG. 5 is a diagram schematically illustrating a correspondence relationship between the imaging result obtained by the imaging device 121 and the composite polarizing plate 111. Note that the p-polarized component transmission region and the s-polarized component transmission region shown in FIG.
A part of the composite polarizing plate 111 shown in FIG.

In FIG. 5, a line E that draws a curve is an attention edge when the first light modulation element unit 400 </ b> A and the second light modulation element unit 400 </ b> B have an appropriate positional relationship, and this is referred to as a reference attention edge E. I will decide.

Here, if the first light modulation element unit 400A and the second light modulation element unit 400B are adjusted so as to have an appropriate positional relationship, the reference target edge E becomes a continuous single line. Here, since the first light modulation element unit 400A is used as a reference, the attention edge of the first image G1 emitted from the first light modulation element unit 400A becomes the reference attention edge E. Therefore, the second image G2 with respect to the target edge (reference target edge E) of the first image G1.
By calculating the projection position shift amount (pixel shift amount) of the target edge E ′ of the first image G
It is possible to obtain the projection position deviation amount (pixel deviation amount) between the first image G2 and the second image G2.

In FIG. 5, black circles represent representative pixels p01, out of pixels (pixels in the green light modulation element 410G) corresponding to the reference target edge E of the first light modulation element unit 400A.
.., and white circles represent representative pixels s11, of the pixels corresponding to the target edge E ′ of the second light modulation element unit 400B (pixels in the green light modulation element 411G). s12, s31, s32,...

Here, if the first light modulation element unit 400A and the second light modulation element unit 400B are at appropriate positions, the pixels p01, p02, p21, p22,.
s12, s31, s32,... should exist along the reference target edge E, but in the example shown in FIG. 5, each pixel p01, p02 of the first light modulation element unit 400A.
, P21, p22,..., Each pixel s11, s of the second light modulation element unit 400B.
12, s31, s32, ... exist in a state shifted downward.

This indicates that a pixel shift occurs in the second light modulation element unit 400B with respect to the reference first light modulation element unit 400A. Therefore, in this case, the pixel shift amount of the second light modulation element unit 400B with respect to the first light modulation element unit 400A is calculated in the sections x1, x3, x5,. The first light modulation element unit 400A and the second light modulation element unit 400B are obtained by performing correction processing for shifting the pixels s1, s2, s31, s32,. An appropriate positional relationship can be obtained. Here, only the projection position deviation in the vertical direction (vertical direction) will be described for the sake of simplicity.

The projection position deviation amount calculation unit 130 calculates the pixel deviation amount of the second light modulation element unit 400B with respect to the first light modulation element unit 400A in the sections x1, x3, x5,. Here, the pixel shift amount of the second light modulation element unit 400B (sections x1, x3)
, X5,..., First, the intervals x1, x3, x5,.
The pixel position of the reference target edge E is obtained as an approximate value from the captured image data.

This can be obtained by interpolation using the pixel position of the reference target edge E in the section adjacent to the sections x1, x3, x5,. Then, the difference between the pixel position of the reference target edge E in the sections x1, x3, x5,... Obtained as the approximate value and the pixel position of the target edge E ′ in the same section is calculated as the pixel shift amount. The pixel shift amount is expressed as the number of pixels such as “2 pixels” and “2.5 pixels”, for example.

Then, the projection position correction apparatus 200 corrects the projection position based on the calculated pixel shift amount. Here, the correction of the projection position is performed by image processing. That is, a process of shifting pixels by the calculated pixel shift amount is performed on the image data to be projected by the projector PJ.

In this case, since the resolution of the imaging device 121 is sufficiently higher than the resolution of each light modulation element of the projector PJ, the projector PJ has a resolution based on the ratio between the resolution of the imaging device 121 and the resolution of each light modulation element. The pixel shift amount of the second light modulation element unit 400B with respect to the first light modulation element unit 400A is calculated, and the pixels are shifted by image processing by the calculated pixel shift amount.

By the way, generally, a polarizing plate cannot always block 100% of light having one of the p-polarized component and the s-polarized component. For example, even a polarizing plate capable of transmitting a p-polarized component does not necessarily block 100% of the s-polarized component. The reverse is also true. Therefore, also in the composite polarizing plate 111 as shown in FIG. 2, the p-polarized component transmission region actually transmits the s-polarized component light to some extent, and the s-polarized component transmission region transmits the p-polarized component light to some extent. It will be. Therefore, the imaging device 121 captures an image having a p-polarized component with a reduced amount of light even in the s-polarized component transmission region, and captures an image having an s-polarized component with a decreased amount of light in the p-polarized component transmission region. Will be.

FIG. 6 is a diagram schematically showing actual imaging results of the first image G1 and the second image G2 that have passed through the composite polarizing plate 111. As shown in FIG. As shown in FIG. 6, each p-polarized component transmission region (section x0, x
2, x 4,..., The target edge E ′ of the s-polarized component with a reduced light amount is imaged. Similarly, in each s-polarized component transmission region (sections x1, x3, x5,...),
The reference attention edge E of the p-polarized component having a reduced amount of light is imaged. In FIG. 6, the attention edge E ′ whose light amount has decreased and its pixels (for example, s01, s02, s21, s22) and the reference attention edge E whose light amount has decreased and its pixels (for example, p11, p12, p31, p32).
Is shown in light gray.

As described above, in the actual imaging result, the attention edge E ′ having the s-polarization component and the reference attention edge E having the p-polarization component exist in the s-polarization component transmission region and the p-polarization component transmission region, respectively. However, since the magnitude of the output level (pixel value) as the captured image data is different, the reference attention edge E having the p-polarized component in each p-polarized component transmission region can be identified by the difference in the output level. And an edge of interest E ′ having an s-polarized component in each s-polarized component transmission region can be identified.

In the above-described example, the p-polarized component transmission region and the s-polarized component transmission region of the composite polarizing plate 111 are in a vertical band-like arrangement as shown in FIG.
The case of detecting the amount of pixel shift in the vertical direction using an edge portion extending in the horizontal direction, that is, an edge portion crossing the p-polarized component transmission region and the s-polarized component transmission region,
It is also possible to calculate the amount of positional deviation in the horizontal direction (left-right direction) by rotating 90 degrees around the optical axis of the composite polarizing plate 111 as shown in FIG. 2 and using the edge portion extending in the vertical direction as the target edge. it can.

That is, first, with the composite polarizing plate 111 installed as shown in FIG. 2, the edge portion extending in the horizontal direction is used as the target edge, and the above-described projection positional deviation amount calculation processing is performed. The image is picked up by the image pickup device 121 in a state of being rotated 90 degrees around the optical axis, an edge portion extending in the vertical direction is detected from the picked-up image data, and the above-described projection position is set with the detected edge portion as a target edge. A deviation calculation process is performed.

Thereby, not only the vertical pixel shift amount but also the horizontal pixel shift amount can be calculated. The first light modulation element unit 4 is corrected by correcting the position of the second light modulation element unit 400B based on the pixel displacement amount in the vertical direction and the pixel shift amount in the horizontal direction thus calculated.
00A and the second light modulation element unit 400B can be set to an appropriate positional relationship in the vertical direction and the horizontal direction.

As another example of a method for calculating both the vertical pixel shift amount and the horizontal pixel shift amount, two composite polarizing plates 111 as shown in FIG. 2 are prepared, and one composite polarizing plate is prepared. 2, the p-polarized component transmissive region and the s-polarized component transmissive region are arranged in a vertical band shape as shown in FIG. 2, and the other composite polarizing plate 111 is a p-polarized component transmissive region and an s-polarized component transmissive region. Are arranged in a horizontal band shape. The two composite polarizing plates 111 are slidable in the left-right direction, and are imaged in a time-division manner by the single imaging device 121. With such a configuration, both the vertical pixel shift amount and the horizontal pixel shift amount can be calculated.

When two composite polarizing plates 111 are prepared in this way, two imaging devices may be provided so as to correspond to each composite polarizing plate 111 instead of sliding the composite polarizing plate 111.

In the above-described projection position deviation amount calculation processing, when the optimum edge that should be the attention edge does not exist in the current captured image data, it waits for the optimum edge to appear as the attention edge. When an optimum edge appears, that edge is used as the target edge.

As described above, in the projection system 10 according to the first embodiment, the composite polarizing plate 111 and the imaging device 121 are used to obtain the captured image data corresponding to the first image G1 having the p-polarized component and the s-polarized component. Captured image data corresponding to the second image G2 is acquired. Then, a target edge is detected from the acquired captured image data, and based on the detected target edge, the green light modulation element 410G of the first light modulation element unit 400A and the green light of the second light modulation element unit 400B. The pixel shift amount of each corresponding pixel of the modulation element 411G is calculated. Based on the pixel shift amount thus calculated, correction is performed so that the first image G1 and the second image G2 have an appropriate positional relationship.

For this reason, according to the projection system according to the first embodiment, the first light modulation element unit 400A is emitted even during normal image projection by the projector PJ without displaying the test pattern. The projection position deviation amount (pixel deviation amount) between the first image G1 and the second image G2 emitted from the second light modulation element unit 400B can be calculated, and the calculated projection position deviation amount (pixel deviation amount). Based on the above, it is possible to perform correction so that the positional relationship between the first image G1 and the second image G2 is an appropriate positional relationship.

[Embodiment 2]
In the projection system 10 according to the first embodiment described above, the composite polarizing plate 111 (see FIG. 2) is used as the superimposed image separation unit 110.
It is also possible to use a polarizing plate that transmits the polarization component (referred to as p-polarization component transmission polarizing plate 112p) and a polarizing plate that transmits the s-polarization component (referred to as s-polarization component transmission polarizing plate 112s).

FIG. 7 is a diagram illustrating a configuration of the projection system 20 according to the second embodiment. Similar to the projection system 10 (see FIG. 1) according to the first embodiment, the projection system 20 according to the second embodiment includes a projector PJ, a projection position deviation amount detection device 100, and a projection position correction device 200. . The projector PJ has the same configuration as the projector PJ in the projection system 10 according to the first embodiment.

The projection position shift amount detection device 100 includes a p-polarized component transmissive polarizing plate 112p and an s-polarized component transmissive polarizing plate 112s as the superimposed image separation unit 110, and an imaging device 121 provided corresponding to the p-polarized component transmissive polarizing plate 112p. (Referred to as the first imaging device 121 in the second embodiment);
An imaging device 122 (referred to as the second imaging device 122 in the second embodiment) provided corresponding to the s-polarized component transmissive polarizing plate 112s, and captured image data (first p-polarized component-containing first imaging device 121). The first image G1 and the second image G2 based on the captured image data corresponding to the image G1) and the captured image data from the second imaging device 122 (captured image data corresponding to the second image G2 having the s-polarized component). Projection position deviation amount calculation unit 130 for calculating the projection position deviation amount
And have.

Also in the projection system 20 as shown in FIG. 7, the amount of projection position deviation between the first image G1 and the second image G2 can be calculated in the same manner as the projection system 10 according to the first embodiment. Note that the amount of projection displacement between the first image G1 and the second image G2 is the second light modulation with respect to the green light modulation element 410G of the first light modulation element unit 400A, as in the projection system 10 according to the first embodiment. It is calculated as a relative pixel shift amount of the green light modulation element 411G of the element unit 400B. When the pixel shift amount is calculated in this way, the projection position correction apparatus 200 performs projection position correction based on the calculated pixel shift amount by image processing.

In the projection system 20 according to the second embodiment, two imaging devices (
In order to calculate the projection position deviation amount using the respective captured image data output from the first imaging device 121 and the second imaging device 122), the captured image data of the first imaging device 121 and the imaging of the second imaging device 122 are calculated. There is a possibility that a spatial shift occurs in the image data. For this reason, an interpolation process for the spatial shift may be necessary, but both the vertical and horizontal projections are performed by the first imaging device 121 and the second imaging device 122 each taking one image. There is also an advantage that the amount of displacement can be calculated.

That is, in the projection system according to the second embodiment, the screen SCR
Since the entire first image G1 and the entire second image G2 projected on the first image G2 can be captured respectively, the first image is obtained from the captured image data corresponding to the first image G1 output from the first imaging device 121. An edge portion extending in the horizontal direction and an edge portion extending in the vertical direction of G1 can be detected, and from the captured image data corresponding to the second image G2 output from the second imaging device 122, the second image An edge portion extending in the horizontal direction and an edge portion extending in the vertical direction of G2 can be detected. As a result, the first image pickup device 121 and the second image pickup device 122 each take a single image, whereby it is possible to calculate both the vertical and horizontal projection position deviation amounts.

In the projection system 20 according to the second embodiment, two imaging devices (
The first imaging device 121 and the second imaging device 122) can simultaneously capture the first image G1 and the second image G2, so that the captured image data from the first imaging device 121 and the second imaging device 122 There is no time lag between the captured image data.

As described above, according to the projection system 20 according to the second embodiment, as in the projection system 10 according to the first embodiment, without displaying a test pattern,
Even during normal image projection by the projector PJ, the first image G1 emitted from the first light modulation element unit 400A and the second image G2 emitted from the second light modulation element unit 400B. The amount of projection position deviation (pixel deviation amount) can be calculated, and based on the calculated amount of projection position deviation (pixel deviation amount), the positional relationship between the first image G1 and the second image G2 is determined as an appropriate positional relationship. It is possible to perform such correction.

[Embodiment 3]
The projection system 30 according to the third embodiment includes p as the superimposed image separation unit 110.
Polarizing component transmission polarizing plate 112p or s polarizing component transmission polarizing plate 112s (p
Polarized component transmissive polarizing plate 112p) is used.

FIG. 8 is a diagram illustrating a configuration of the projection system 30 according to the third embodiment. The overall configuration of the projection system 30 according to the third embodiment is the same as that of the projection system 10 according to the first embodiment (see FIG. 1), and includes a projector PJ, a projection position deviation amount detection device 100, and a projection position correction device 200. have. The projector PJ has the same configuration as the projector PJ in the projection system 10 according to the first embodiment.

The projection position shift amount detection device 100 includes a p-polarized component transmissive polarizing plate 112p as the superimposed image separation unit 110, an imaging device 121 provided corresponding to the p-polarized component transmissive polarizing plate 112p,
A projection position deviation amount calculation unit 130 that calculates a deviation amount of the projection positions of the first image and the second image based on the captured image data from the imaging device 121;

Further, the p-polarized component transmissive polarizing plate 112p is installed so as to be capable of rotating by 90 degrees about the optical axis. Therefore, the p-polarized component transmissive polarizing plate 112p can transmit the s-polarized component in a state where the p-polarized component transmissive polarizing plate 112p is rotated 90 degrees from the initial state when the position where the p-polarized component can be transmitted is in the initial state. Note that the rotation direction around the optical axis of the p-polarized component transmissive polarizing plate 112p may be rotated by 90 degrees in one direction (for example, clockwise), and can be rotated by 90 degrees in the clockwise and counterclockwise directions, respectively. It is good.

In the projection system 30 according to the third embodiment, first, the imaging device 121 is set with the p-polarized component transmissive polarizing plate 112p in an initial state (a state in which the p-polarized component can be transmitted).
The captured image data (first image G1 having a p-polarized component) obtained by imaging
(Captured image data corresponding to) is output to the projection position deviation amount calculation unit 130. Subsequently, imaging is performed by the imaging device 121 with the p-polarized component transmissive polarizing plate 112p rotated by 90 degrees from the initial state, and captured image data (corresponding to the second image G2 having the s-polarized component) is obtained. Captured image data) to be output to the projection position deviation amount calculation unit 130.

In the projection position deviation amount calculation unit 130, based on the captured image data corresponding to the first image G1 and the captured image data corresponding to the second image G2 output from the imaging device 121, the first light modulation element unit 400A. Second light modulation element unit 4 for green light modulation element 410G
The pixel shift amount of each corresponding pixel of the 00B green light modulation element 411G is calculated.
When the pixel shift amount is calculated in this way, the projection position correction apparatus 200 performs projection position correction based on the calculated pixel shift amount by image processing.

In the projection system 30 according to the third embodiment, the first having a p-polarized component.
Since the image and the second image having the s-polarized component are picked up in a time-sharing manner, a correction corresponding to the temporal shift of the image may be necessary for a rapidly moving image. (P
The polarizing component transmissive polarizing plate 112p or the s-polarized component transmissive polarizing plate 112s) and one imaging device 121 are sufficient. Thereby, the configuration can be simplified, and there is an advantage that it can be realized at low cost.

Further, in the projection system 30 according to the third embodiment, it is possible to calculate both the vertical and horizontal projection position deviation amounts by capturing the first image G1 and the second image G2 once each. That is, in the projection system according to the third embodiment, from the captured image data corresponding to the first image G1 output from the imaging device 121, an edge portion extending in the horizontal direction and an edge portion extending in the vertical direction in the first image G1. From the captured image data corresponding to the second image G2 output from the imaging device 121, an edge portion extending in the horizontal direction and an edge portion extending in the vertical direction in the second image G2 are detected. Can be detected. Accordingly, it is possible to calculate the amount of projection position deviation in both the vertical direction and the horizontal direction only by capturing the first image G1 and the second image G2 once each.

As described above, according to the projection system 30 according to the third embodiment, as in the projection system according to each of the above-described embodiments, without displaying a test pattern,
Even during normal image projection by the projector PJ, the first image G1 emitted from the first light modulation element unit 400A and the second image G2 emitted from the second light modulation element unit 400B. The amount of projection position deviation (pixel deviation amount) can be calculated, and based on the calculated amount of projection position deviation (pixel deviation amount), the positional relationship between the first image G1 and the second image G2 is determined as an appropriate positional relationship. It is possible to perform such correction.

[Embodiment 4]
Each of the above-described embodiments selectively uses various polarizing plates such as the composite polarizing plate 111, the p-polarized component transmissive polarizing plate 112p, and the s-polarized component transmissive polarizing plate 112s as the superimposed image separating unit 110, and the p-polarized component is used. The first image G1 having and the second image G2 having the s-polarized component are separated, but either the p-polarized component transmitting polarizing plate 112p or the s-polarizing component transmitting polarizing plate 112s (p-polarized component transmitting) It is also possible to combine a polarizing plate 112p) and a TN liquid crystal.

FIG. 9 is a diagram illustrating a configuration of the projection system 40 according to the fourth embodiment. The overall configuration of the projection system 40 according to the fourth embodiment is similar to that of the projection system 10 according to the first embodiment (see FIG. 1), and includes a projector PJ, a projection position deviation amount detection device 100, and a projection position correction device 200. have. The projector PJ has the same configuration as the projector PJ in the projection system 10 according to the first embodiment.

The projection misregistration amount detection apparatus 100 includes a superimposed image separation unit 110 including a p-polarized component transmissive polarizing plate 112p and a TN liquid crystal. That is, the projection positional deviation amount detection device 100 in the projection system 40 according to the fourth embodiment includes the p-polarized component transmissive polarizing plate 112.
p, a TN type liquid crystal 113 disposed on the front side (screen SCR side) of the p-polarized component transmissive polarizing plate 112p, the imaging device 121, and the first image G1 based on the captured image data from the imaging device 121 and Projection position deviation amount calculation unit 13 for calculating the projection position deviation amount of the second image G2.
0.

The TN-type liquid crystal 113 transmits both the p-polarized component and the s-polarized component when the drive voltage is applied to the TN-type liquid crystal 113, and in the state where the drive voltage is not applied to the TN-type liquid crystal 113,
The p-polarized component is transmitted as the s-polarized component, and the s-polarized component is transmitted as the p-polarized component.

The TN liquid crystal 113 having such characteristics is placed on the front side of the p-polarized component transmissive polarizing plate 112p (
By arranging on the screen SCR side, when the drive voltage is applied to the TN type liquid crystal 113, both the first image G1 having the p-polarized component and the second image G2 having the s-polarized component are transmitted through the TN type liquid crystal. To do. Then, the first image G1 transmitted through the TN liquid crystal 113 is transmitted through the p-polarized component transmissive polarizing plate 112p and is incident on the imaging device 121, and is captured by the imaging device 121. On the other hand, the second image G2 having the s-polarized component transmitted through the TN liquid crystal 113 is
The second image G2 cannot be transmitted through the p-polarized component transmissive polarizing plate 112p.
In, it is not imaged.

Further, in the state where the driving voltage is not applied to the TN liquid crystal 113, the first having a p-polarized component.
The image G1 is transmitted as a first image G1 having an s-polarized component, and the second image G2 having an s-polarized component is transmitted as a second image G2 having a p-polarized component. Therefore, the first image G1 having the s-polarized component transmitted through the TN liquid crystal 113 (originally the first image G1 having the p-polarized component).
) Cannot pass through the p-polarized component transmissive polarizing plate 112p and is not imaged by the imaging device 121.
On the other hand, the second image G2 having the p-polarized component transmitted through the TN liquid crystal 113 (originally the second image G2 having the s-polarized component) is transmitted through the p-polarized component transmissive polarizing plate 112p, and the imaging device 1
21 and is imaged by the imaging device 121.

Even when the superimposed image separation unit 110 has such a configuration, the imaging device 121
A first image G1 originally having a p-polarized component and a second image G2 originally having an s-polarized component
And can be imaged separately. Also in this case, the first image G1 and the second image G2
In a time-sharing image, there may be a need for correction corresponding to the temporal shift of the image, but there is an advantage that only one imaging device is required,
Since the first image G1 and the second image G2 can be separated only by controlling the application of voltage to the TN liquid crystal 113, there is an advantage that a mechanism for rotating and sliding the polarizing plate becomes unnecessary.

Further, in the projection system 40 according to the fourth embodiment, as in the projection system according to the third embodiment, only the first image G1 and the second image G2 are captured once, and both the vertical and horizontal projections are performed. The amount of displacement can be calculated.

As described above, according to the projection system 40 according to the fourth embodiment, as in the projection system according to each of the above embodiments, the test pattern is not displayed.
Even during normal image projection by the projector PJ, the first image G1 emitted from the first light modulation element unit 400A and the second image G2 emitted from the second light modulation element unit 400B. A projection position shift amount (pixel shift amount) can be calculated, and based on the calculated projection position shift amount (pixel shift amount), the positional relationship between the first image and the second image is set to an appropriate positional relationship. Such correction can be performed.

[Embodiment 5]
The projection system according to each of the above embodiments includes two light modulation element units (
The projection system uses the projector PJ having the first light modulation element unit 400A and the second light modulation element unit 400B). The projection system performs stacking projection using a plurality of projectors having one light modulation element unit. The same can be applied to the system.

FIG. 10 is a diagram illustrating a configuration of a projection system 50 according to the fifth embodiment. A projection system 50 according to the fifth embodiment is a projection system configured to perform stacking projection by two projectors PJ1 and PJ2, as shown in FIG. 10, and an image (first image) projected from the projector PJ1. G1)
An image projected from the projector PJ2 (referred to as a second image G1) is a screen SCR.
It is displayed in a superimposed state.

In addition, the projection system 50 according to the fifth embodiment includes a projection position deviation amount detection device 100 that detects a projection position deviation amount between the first image G1 projected from the projector PJ1 and the second image G2 projected from the projector PJ2. The projection position correction apparatus 200 corrects the projection positions of the first image G1 and the second image G2 based on the projection position deviation amount detected by the projection position deviation amount detection apparatus 100.

Similar to the projection system 10 according to the first embodiment, the projection position deviation amount detection apparatus 100 includes a composite polarizing plate 111 as the superimposed image separation unit 110, an imaging device 121, and a projection position deviation amount calculation unit 130. .

Although not shown, the optical devices of the projectors PJ1 and PJ2 have the same configuration as that of a general projector. That is, the projectors PJ1 and PJ2 are a light source that emits light including RGB, an integrator optical system, a light modulation element unit, and a color separation that separates the light from the light source into RGB color lights and guides them to the light modulation element unit. A light guide optical system; and a projection optical system that enlarges and projects an image emitted from the light modulation element unit onto the screen SCR.

The light modulation element unit of the projector PJ1 is the first light modulation element unit 400A.
And the light modulation element unit of the projector PJ2 is a second light modulation element unit 400B. The first light modulation element unit 400A and the second light modulation element unit 400B are:
It has the same configuration as the first light modulation element unit 400A and the second light modulation element unit 400B shown in FIG. That is, the first light modulation element unit 400A includes the light modulation elements 410R, 410G, and 410B and the cross dichroic prism 420 as shown in FIG.
The light modulation elements 410R, 410G, 410B and the cross dichroic prism 420 are integrated. The second light modulation element unit 400
3, B also has light modulation elements 411R, 411G, and 411B and a cross dichroic prism 421, and these light modulation elements 411R, 411G, and 411B and the cross dichroic prism 421 are integrated. It has a structure.

The first image G1 projected from the projector PJ1 has a p-polarized component, and the second image G2 projected from the projector PJ2 has an s-polarized component.

When stacking projection as shown in FIG. 10 is performed using such projectors PJ1 and PJ2, the second light modulation in each of the light modulation elements 410R, 410G and 410B of the first light modulation element unit 400A in the projector PJ1 and the projector PJ2. It is necessary to adjust the position of the projector PJ1 and the projector PJ2 with high accuracy so that the positional relationship between the corresponding pixels of the light modulation elements 411R, 411G, and 411B of the element unit 400B is appropriately adjusted.

In the projection system 50 according to the fifth embodiment, similarly to the projection system 10 according to the first embodiment, a composite polarizing plate 111 (FIG. 2) is used as the superimposed image separation unit 110.
The composite polarizing plate 111 is placed on the front side of the imaging device 121 (screen SCR side).
Is arranged. Due to such a configuration, similar to the projection system 10 according to the first embodiment, the imaging device 121 can separately capture the superimposed images (first image G1 and second image G2) on the screen SCR. . Then, based on the captured image data output from the imaging device 121, the positional deviation amount calculation unit 1 calculates the projection positional deviation amount between the first image G1 projected from the projector PJ1 and the second image G2 projected from the projector PJ2.
30 can be calculated.

Note that the amount of projection position deviation between the first image G1 and the second image G2 is the green light modulation element 4 of the first light modulation element unit 400A, as in the projection system 10 according to the first embodiment.
It is calculated as a relative pixel shift amount of the green light modulation element 411G of the second light modulation element unit 400B with respect to 10G. When the pixel shift amount is calculated in this way, the projection position correction apparatus 200 performs projection position correction based on the calculated pixel shift amount by image processing.

As described above, according to the projection system 50 according to the fifth embodiment, the projection pattern P50 is projected from the projector PJ1 even while a normal image is being projected by the projectors PJ and PJ2, without displaying the test pattern. A projection position deviation amount (pixel deviation amount) between the first image G1 and the second image G2 projected from the projector PJ2 can be calculated. Based on the calculated projection position deviation amount (pixel deviation amount), the projector P
It is possible to perform correction so that the positional relationship between J1 and the projector PJ2 is an appropriate positional relationship.

In the projection system 50 according to the fifth embodiment, the superimposed image separation unit 1
10 can have the same configuration as each of the superimposed image separation units 110 used in the projection system 20 according to the second embodiment, the projection system 30 according to the third embodiment, and the projection system 40 according to the fourth embodiment.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, the following modifications (1) to (4) are possible.

(1) The composite polarizing plate 111 used in Embodiments 1 and 5 has a configuration in which p-polarized component transmission regions and s-polarized component transmission regions are alternately arranged in a band shape (FIG. 2).
The configuration is not limited to such a configuration. For example, a grid-shaped p-polarized component transmission region and an s-polarized component transmission region may alternately exist in the vertical direction and the horizontal direction. In addition, in a half area (for example, the left half area) of the composite polarizing plate 111, a band-shaped p-polarized component transmission area and a band-shaped s-polarized component transmission area alternately exist in the vertical direction. 1 /
The two regions (for example, the right half region) may have a configuration in which a band-shaped p-polarized component transmission region and a band-shaped s-polarized component transmission region alternately exist in the horizontal direction.
The entire ½ region (for example, the left half region) is the p-polarized component transmission region, and the other ½ region (for example, the right half region) is the s-polarized component transmission region. It may be configured.

By adopting such a configuration for the composite polarizing plate 111, captured image data obtained from one imaging device without providing a mechanism for rotating the composite polarizing plate 111 or sliding two composite polarizing plates. Therefore, not only the edge portion extending in the horizontal direction but also the edge portion extending in the vertical direction can be detected, so that the projection position deviation amount in the vertical direction and the horizontal direction can be calculated.

Further, as another example of a method for calculating both the vertical projection position deviation amount and the horizontal projection position deviation amount, an edge existing in an oblique direction (for example, 45 degrees or an inclination before and after that) is taken from the captured image data. It is also possible to calculate both the vertical pixel shift amount and the horizontal pixel shift amount by detecting the detected edge as a target edge. This is not only a projection system using the composite polarizing plate 111 but also a projection system using another polarizing plate (the projection system 20 according to the second embodiment,
The same applies to the projection system 30 according to the third embodiment and the projection system 40 according to the fourth embodiment.

(2) In the projection system 20 according to the second embodiment, two imaging devices (
The first imaging device 121 and the second imaging device 122) are used.
The first image G1 that is transmitted through the polarization component transmission polarizer 112p and the s polarization component transmission polarizer 112s.
You may make it image alternately the 2nd image G2 which permeate | transmits.

(3) In the projection system 50 according to the fifth embodiment, one of the two projectors PJ1 and PJ2 (projector PJ1) projects the first image G1 having a p-polarized component, and the other projector (projector) PJ2) is s
Although the second image G2 having the polarization component is projected, during normal image projection,
The projectors PJ1 and PJ2 may project an image having the same polarization component, and one projector may have a polarization component different from that of the other projector when detecting the amount of projection position deviation. This is because, for example, a projector PJ is used during normal image projection.
1 and PJ2 both project an image having a p-polarized component, and when detecting the amount of projection displacement, the polarized light is converted so that the image projected from the projector PJ2 becomes an s-polarized component. It is.

(4) In each of the above embodiments, the projection position deviation calculation unit 130 and the projection position correction apparatus 200 are external components of the projector PJ (in the projection system 50 according to the fifth embodiment, the projectors PJ1 and PJ2). Although the case is shown, the projection position deviation amount calculation unit 130 and the projection position correction apparatus 200 are connected to the projector PJ (
In the projection system 50 according to the fifth embodiment, the projectors PJ1, PJ
2) It may be provided inside.

(5) In each of the above embodiments, the pixel shift amount is calculated using the edge detected from the captured image data. However, when imaging is performed at a high magnification, the pixel center is calculated by calculating the center of gravity of the pixel. It is also possible to calculate the deviation amount.

(6) In each of the above embodiments, the projection position is corrected by image processing. However, for example, the relative positions of the first light modulation element unit 400A and the second light modulation element unit 400B are not image processing. May be adjusted.

10, 20, 30, 40, 50 ... projection system, 100 ... projection position shift amount detection device, 110 ... superimposed image separation unit, 111 ... composite polarizing plate, 112p
... P-polarized component transmissive polarizing plate, 112s... S-polarized component transmissive polarizing plate, 113... TN liquid crystal, 121... Imaging device (first imaging device), 122. 130 ...
Projection position deviation amount calculation unit, 200... Projection position correction device, 400 A, first light modulation element unit, 400 B, second light modulation element unit, G 1, first image, G 2.・
Second image, PJ ... projector, PJ1 ... first projector, PJ2 ...
Second projector, SCR ... screen

Claims (14)

Projection position shift between the first image and the second image when the first image having the first polarization component and the second image having the second polarization component are projected on the projection surface. A projection position deviation amount detection device for detecting the amount,
A superimposed image separating unit that separates the first image and the second image projected in a state of being superimposed on the projection surface based on a difference in polarization components;
An imaging device that captures the first image and the second image separated by the superimposed image separation unit, and outputs captured image data corresponding to the first image and captured image data corresponding to the second image; ,
A projection position deviation amount calculation unit that calculates a projection position deviation amount between the first image and the second image based on the captured image data corresponding to the first image and the captured image data corresponding to the second image;
A projection position deviation amount detecting device characterized by comprising: In the projection position shift amount detection device according to claim 1,
The superimposed image separating unit is a composite polarization in which a first polarization component transmission region that transmits the first polarization component and a second polarization component transmission region that transmits the second polarization component are formed on one polarizing plate. A projection position deviation amount detection device characterized by being a plate. In the projection position shift amount detection device according to claim 2,
The projection position deviation amount detection device, wherein the first polarization component transmission region and the second polarization component transmission region are alternately formed in a band shape in the polarizing plate. In the projection position shift amount detection device according to claim 2,
The first polarization component transmission region and the second polarization component transmission region are divided into two regions by dividing the polarizing plate into two regions.
A projection position deviation amount detection device, wherein the projection position deviation amount detection device is formed in one region and the other region when divided. In the projection position shift amount detection device according to claim 1,
The superimposed image separation unit is a polarizing plate that is one of a first polarizing component transmitting polarizing plate that transmits the first polarizing component or a second polarizing component transmitting polarizing plate that transmits the second polarizing component,
An apparatus for detecting a displacement of projection position, wherein the first polarizing component transmission polarizing plate or the second polarization component transmission polarizing plate is installed so as to be rotatable by 90 degrees. In the projection position shift amount detection device according to claim 1,
The superimposed image separation unit includes two polarizing plates, a first polarizing component transmitting polarizing plate that transmits the first polarizing component and a second polarizing component transmitting polarizing plate that transmits the second polarizing component. Projection displacement detection device. In the projection position shift amount detection device according to claim 1,
The superimposed image separation unit includes either a first polarizing component transmitting polarizing plate that transmits the first polarizing component or a second polarizing component transmitting polarizing plate that transmits the second polarizing component, and TN (
A projection position characterized in that the first image and the second image can be transmitted separately by controlling the application of a driving voltage to the TN liquid crystal by using a twisted nematic) liquid crystal in combination. Deviation detection device. In the projection position shift amount detection apparatus according to any one of claims 1 to 7,
The projection position deviation amount calculation unit detects an edge portion common to the first image and the second image from the captured image data corresponding to the first image and the captured image data corresponding to the second image, and An apparatus for detecting a displacement of projection position, wherein a relative displacement amount of projection position between the first image and the second image at the detected edge portion is calculated. In the projection position shift amount detection apparatus according to claim 8,
The relative projection displacement between the first image and the second image is determined by the light modulation element of the first light modulation element unit that emits the first image and the second light modulation element that emits the second image. A projection position deviation amount detecting device, wherein the projection position deviation amount detection apparatus is calculated as a pixel deviation amount of a pixel corresponding to each of the light modulation elements of the unit. Projection position shift between the first image and the second image when the first image having the first polarization component and the second image having the second polarization component are projected on the projection surface. A method for detecting a displacement amount of a projection position for detecting an amount,
Separating the first image and the second image projected in a state of being superimposed on the projection surface based on a difference in polarization components;
Capturing the first image and the second image separated by the superimposed image separation unit, and outputting captured image data corresponding to the first image and captured image data corresponding to the second image;
Calculating a projection position shift amount between the first image and the second image based on the captured image data corresponding to the first image and the captured image data corresponding to the second image;
A projection position deviation amount detection method characterized by comprising: A first light modulation element unit that projects a first image having a first polarization component on a projection plane;
A second light modulation element unit that projects a second image having a second polarization component onto the projection plane in a state of being superimposed on the first image;
A superimposed image separating unit that separates the first image and the second image based on a difference in polarization components;
An imaging device that captures the first image and the second image separated by the superimposed image separation unit, and outputs captured image data corresponding to the first image and captured image data corresponding to the second image; ,
A projection position deviation amount calculation unit that calculates a projection position deviation amount between the first image and the second image based on the captured image data corresponding to the first image and the captured image data corresponding to the second image;
A projection system comprising: The projection system according to claim 11, wherein
A polarization combining optical system for combining the first image and the second image;
A projection optical system that projects the first image and the second image synthesized by the polarization synthesis optical system onto the projection plane;
The projection system, wherein the first light modulation element unit, the second light modulation element unit, the polarization combining optical system, and the projection optical system are provided in one projector. The projection system according to claim 11, wherein
A first projector including a first projection optical system that projects the first light modulation element unit and a first image emitted from the first light modulation element unit onto the projection plane;
A second projector including a second projection optical system that projects the second light modulation element unit and a second image emitted from the second light modulation element unit onto the projection plane;
A projection system comprising: In the projection system of Claims 11-13,
Projection positions of the first image emitted from the first light modulation element unit and the second image emitted from the second light modulation element unit based on the projection position deviation amount calculated by the projection position deviation amount calculation unit A projection system, further comprising a projection position correcting device for correcting the above.