JP2008116624A - Projector and method for compensating chromatic difference of magnification - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which achieves high-quality image display of sub-pixel accuracy and where a lens system for correcting the chromatic difference of magnification of a projection optical system is eliminated, and to provide a method for compensating chromatic difference of magnification. <P>SOLUTION: The projector includes: a light source; a separation device 11 which separates a light beam emitted from the light source into a plurality of color light beams; spatial optical modulators on which the plurality of color light beams are made incident and which correspond to the respective color light beams for forming respective color images in accordance with respective color image signals; a color synthesizing optical system which synthesizes the respective color light beams emitted from the spatial optical modulators; and a projection optical system which projects the light beam synthesized by the color light synthesizing optical system. The projector is equipped with a magnification converter 11 for adjusting size in a predetermined direction of each color image signal input in the spatial optical modulator. The size in the predetermined direction of each color image formed by each of the plurality of color light beams is arranged to be uniform between the respective colors. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector for projecting image light and a method for compensating for lateral chromatic aberration of an optical system thereof.

  A projector that projects and displays a color image includes a light source, an illumination optical system, a color light separation optical system, a liquid crystal panel for each separated color light, a color synthesis optical system, and a projection optical system. In the case where the light source is originally separated into each color light, the color light separation optical system is excluded.

  The light from the illumination optical system is separated into three color lights of red, green, and blue by the color light separation optical system, and each color light is modulated by a spatial light modulator such as a liquid crystal panel, and an image for each color light is formed. After being generated, they are synthesized by the color synthesis optical system and projected through the projection optical system. The projection optical system forms an image of the synthesized three color lights on the projection screen and forms a color image on the projection screen.

  Patent Document 1 discloses a display device of a type that obtains a color display by combining a monochrome liquid crystal panel and a light source whose emission color is switched between red, blue, and green. This method is called a “field sequential color method”.

  In the field sequential color system, the emission color of the light source is switched to red, blue, and green, and at the same time, an image corresponding to each emission color is sequentially displayed on the panel and driven to sequentially project each color light from the projection optical system. . The projection optical system forms an image on the projection screen by forming three color lights that are sequentially displayed on the projection screen.

  Such a “field sequential color system” projection display device does not require the color separation optical system and the color light combining optical system described above, and only one spatial modulation element is required. Since the configuration of the optical system for projecting the image can be simplified, it can be configured as a small, light, and inexpensive device. The “field sequential color method” has an advantage that the number of pixels of the display image can be tripled compared to the case where the pixels corresponding to the respective primary color components are integrated on a single panel.

  However, in the field-sequential projection display apparatus, 2/3 of the light emitted from the light source is cut out corresponding to two primary colors, so that the light utilization rate is 1/3 or less corresponding to one primary color. turn into.

  However, since the projection optical system used in the projection display device usually has chromatic aberration of magnification, there is a problem that the size of the projection screen differs for each color light. On the other hand, a lens for correcting magnification chromatic aberration can be included in the lens system constituting the projection optical system, but the projection optical system becomes large.

  For this reason, the projection optical system is enlarged by providing a lens element or a prism element between the exit surface of the spatial light modulator and the entrance surface of the color light combining optical system, specifically, the entrance surface of the color light combining prism. A technique for correcting the chromatic aberration of magnification without doing this is known (see Patent Document 2). In addition, there is a color synthesis prism that is a color light synthesis optical system in which the dichroic surface of the color synthesis prism is convex or concave (see Patent Document 3).

  However, since the gap from the exit surface of the spatial light modulator to the entrance surface of each light combining prism is narrow, it is possible to dispose an independent lens element or prism element in the gap. This further narrows the distance from the light incident surface, thereby reducing the cooling performance of the spatial light modulator.

  In addition, forming lens elements and prism elements on the entrance surface of the color light combining prism is often difficult in practice in consideration of the shape and function of the color light combining prism.

  However, if the gap from the exit surface of the spatial light modulator to the entrance surface of each light combining prism is increased, the projection optical system itself becomes larger, making it difficult to realize an ultra-compact projector.

  On the other hand, conventionally, display devices using various display devices have been used. Among such display devices, for example, as shown in FIG. 1, a color developing element that develops each of the three primary colors RGB (red is R, green is G, and blue is B), such as a liquid crystal display or a plasma display. A single pixel is formed by arranging in one direction (first direction) in a fixed order, and a single line is formed by arranging a plurality of pixels in parallel in the first direction. Some display screens are formed by providing a plurality in the orthogonal direction. At this time, each light emitting element is smaller than one pixel and is called a subpixel.

  Usually, in a display device, control is performed using one pixel as a minimum unit of display. However, if you try to display characters, photos, complex graphics, etc. on a display device that has a narrow display screen and is difficult to display in detail, such as a display device installed in a mobile phone or mobile computer, the resolution is low. Shaggy tends to occur on the diagonal line.

  Non-Patent Document 1 and Patent Document 4 disclose high-quality display technology with sub-pixel accuracy as conventional techniques for improving the resolution of image display. In this method, by controlling the sub-pixels individually, the visibility can be improved as compared with the display with simple pixel accuracy.

  However, this method is a correction method mainly for a liquid crystal monitor or a CRT monitor, and cannot be applied to a projector as it is.

  On the other hand, a three-plate projector using three liquid crystal display elements for RGB, a reflective liquid crystal panel, and a micromirror corresponding to each pixel called a micromirror device, display RGB images in a time-sharing manner. In the projector of this type, if each color projected on the screen is separated and characters and the like look double, the resolution and the image quality are impaired. Therefore, in order to prevent this, it is necessary to satisfactorily superimpose the pixels of each color over the entire range of the screen as shown in FIG. Therefore, it is necessary to satisfactorily correct the color shift (magnification chromatic aberration) generated in the projection lens over the entire visible light range.

  However, when correcting the chromatic aberration of magnification with the projection optical system itself, the number of lenses constituting the projection optical system is increased. In addition, the above-described high-quality display technology with subpixel accuracy cannot be applied.

Patent Document 5 discloses a color projector that can improve the image quality by compensating the chromatic aberration of the projection optical system by changing the size and position of the spatial color modulator for each color, and can reduce the design of the projection lens unit. Is disclosed.
The difference in size of each color of the spatial light modulator for correcting chromatic aberration is minimal, and it is difficult as a practical matter to design and manufacture a spatial light modulator having a slightly different size for each color.
JP-A-56-27198 JP 2000-206450 A JP-A-11-38210 JP 2004-177679 A Japanese Patent No. 3264916 http://grc.com/cleartype.htm

  As described above, the conventional projector has a problem in that when the chromatic aberration of magnification of the projection optical system is to be corrected, the optical components of the projection optical system need to be increased or increased in size, and an image cannot be displayed with high accuracy. there were.

  The present invention has been made in view of the above problems of a projector, and is capable of displaying a high-quality image with sub-pixel accuracy, and a projector and a magnification in which a lens system for correcting magnification chromatic aberration of a projection optical system is omitted. It is an object of the present invention to provide a chromatic aberration compensation method.

In order to achieve the above object, the present invention provides, as a first aspect, a light source, a separation optical system that separates light emitted from the light source into a plurality of color lights, and a plurality of color lights incident on each color image signal. Accordingly, a spatial light modulator corresponding to each color light for forming an image of each color, a color light synthesis optical system for synthesizing each color light emitted from the spatial light modulator, and light synthesized by the color light synthesis optical system A projection optical system for projecting, comprising a magnification converter for adjusting a size along a predetermined direction of an image signal of each color input to a spatial light modulator, and each of a plurality of color lights It is an object of the present invention to provide a projector characterized in that the size of each color image formed along a predetermined direction is made uniform among the colors.
With such a configuration, by setting the magnification corresponding to the image signal of each color with the magnification converter, it is possible to compensate for blurring of the image caused by the chromatic aberration of magnification of the projection optical system, and thus the projection with a small number of chromatic aberrations. Also in the lens system, it is possible to project on the screen a high quality image that has been subjected to lateral chromatic aberration correction that is equivalent to or higher than that of a projection optical system having a large number of lenses.

In order to achieve the above object, the present invention provides, as a second aspect, a light source, a spatial light modulator for forming an image according to an image signal when light emitted from the light source is incident, A projector having a projection optical system for projecting an image formed by a light modulator,
A magnification converter for adjusting a size along a predetermined direction of an image of each color formed by light emitted from a light source is provided, and the image of each color formed by each of a plurality of color lights is aligned along a predetermined direction. The present invention provides a projector characterized by aligning the sizes between colors.
With this configuration, by setting the magnification corresponding to the image signal of each color with the magnification converter, it is possible to compensate for blurring of the image caused by the chromatic aberration of magnification of the projection optical system. Also in the lens system, it is possible to project on the screen a high quality image that has been subjected to lateral chromatic aberration correction that is equivalent to or higher than that of a projection optical system having a large number of lenses.

In the second aspect of the present invention, the color light of the light source is three colors of red, blue, and green, and the magnification converter sets the size along the predetermined direction of the projection screen projected by the three color light for each color. It is preferable to adjust the size of each color image signal input to the spatial light modulator along a predetermined direction so as to match with each other.
In such a configuration, when an LED, LD, or the like is used as the light source, the color shift on the projection screen due to chromatic aberration of the projection optical system is clearly separated at three points because the wavelength range of each color light is short. When correction is performed in a time series using three spatial light modulators or one, correction is facilitated.

In any of the above-described configurations of the first aspect or the second aspect of the present invention, it is preferable that the magnification factor in the magnification converter is larger as the color light has a longer wavelength.
When the number of projection lenses is reduced, the entire projection lens system is an enlargement system, so that a blue image becomes larger. Therefore, it is necessary to make the magnification for the red image larger than the magnification for the blue image.

Further, in any of the above-described configurations of the first aspect or the second aspect of the present invention, the apparatus further includes a reference image signal projection unit and a projection image detection unit for projecting a reference projection image, and the reference image signal It is preferable that the sizes along the predetermined direction of the reference projection image projected by the projection unit and obtained by the projection image detection unit are made uniform among the colors.
The reference projection image detected by the projection image detection means is analyzed, the size of the image is calculated between the colors, and the magnification of the magnification converter can be set to a magnification that matches the size between the colors.

In order to achieve the above object, as a third aspect, the present invention provides a spatial light modulator that aligns the sizes of a plurality of projection screens projected by a plurality of color lights along a predetermined direction between the colors. When the magnification conversion process for adjusting the size of the image signal of each color input to the color image in a predetermined direction and the coordinates of each pixel of each color light image do not match before and after the conversion, each adjacent color of the image before conversion A complementary value calculating step of calculating the luminance value of the corresponding pixel by complementation from the luminance value of the pixel of light. In the complementary value calculating step, complementing is performed using an intermediate value of the luminance of each pixel of each color light. And a method for compensating for chromatic aberration of magnification of a projector, wherein the gradation is adjusted for each color.
In this way, even if the amount of movement of the pixel is 1 pixel or less due to the conversion magnification of the image converted by the magnification converter for each color light, the luminance of the pixel of each adjacent color light using the sub-pixel shift interpolation principle Since the luminance value of the corresponding pixel is calculated from the value by complementation, the diagonal line in the projection screen is not jagged and smooth. Furthermore, since the sub-pixels are also used for the supplement, the diagonal line portion of the character can be supplemented using the intermediate gradation, which is smoother than the anti-aliasing process. A smoother expression is possible by adjusting the gradation for each color of RGB instead of simple gray.

  According to the present invention, a projector that has been made in view of the above-described problems of a projector, can display a high-quality image with subpixel accuracy, and omits a lens system for correcting lateral chromatic aberration of the projection optical system. And a lateral chromatic aberration compensation method can be provided.

A preferred embodiment of the present invention will be described.
As shown in FIG. 11, the projector according to the present embodiment includes a pre-filter that changes the magnification of each color of the original image and outputs it as a converted image.

  FIG. 12 shows the configuration of the prefilter. The pre-filter is output from a decomposer that decomposes the original image into images of each color component, a magnification changer that changes the magnification of each color component image according to the magnification aberration generated in the projection system, and a magnification converter. And a synthesizer that synthesizes the scaled images of the respective color components to generate a converted image. In the case of data that is originally decomposed into images of the respective color components, the data is input to the magnification converter without going through the separator.

[First operation example]
The lateral chromatic aberration of the optical system will be described with reference to FIG. Considering a projection optical system using a lens, a glass lens has dispersion characteristics, and the refractive index slightly differs depending on the wavelength. In a lens system in which a plurality of single lenses are combined, the so-called “achromatic” is designed in which the dispersion characteristic of each lens is taken into consideration and the total dispersion characteristic of the system is “0”. Projection lenses used in portable projectors are limited in that the number of projection lenses cannot be increased in order to reduce the size, and it is difficult to make the total dispersion “0” well by complementing the dispersion characteristics of each lens. It is.
For example, when projecting a white circle, as shown in FIG. 9A, the red image, the green circle, and the blue circle have the same size in the original image, and the red, green, and blue additive subtractive colors are used. To reproduce white.
If the dispersion characteristics remain in the projection optical system, for example, as shown in FIG. 9B, the red circle is projected slightly smaller and the blue circle is projected slightly larger. In this case, when red, green and blue circles are mixed, the edge of the white circle becomes blue and the image is blurred.

  Therefore, when a blue line is generated in the figure due to the optical characteristics of the projector, the magnification of the original image is changed using a pre-filter as shown in FIG. That is, prior to inputting the image light to the projection optical system, the magnification of each color image is changed so that the magnification aberration is compensated.

  In this operation, the magnification of each color of the original image is individually changed (including equal magnification) by the pre-filter and output as a converted image.

  More specifically, in the pre-filter, the original image is decomposed into images of respective color components by a decomposer. In the magnification converter, an image of each color component is formed at a magnification that cancels the aberration according to the chromatic aberration of magnification generated in the projection system, such as a slightly larger red image and a slightly smaller blue image. An image of each color component is synthesized by a synthesizer to obtain a converted image.

  In general, since the spatial light modulator corresponds to the wavelength of each light source, in the case of a projector using each color three-plate liquid crystal cell as a spatial light modulator, as shown in FIG. It is also possible to input the image to be projected directly to the spatial light modulator. Images converted to spatial light by the spatial light modulators are combined and pass through the projection optical system. On the screen, a color blur at the peripheral edge caused by the magnification of each wavelength being different due to the lateral chromatic aberration of the projection system is corrected, and an image with resolution is reproduced from the center to the peripheral edge.

  In the case of a single-panel liquid crystal projector using so-called field sequential driving, a magnification converter is provided before an original image is input to the spatial light modulator as shown in FIG. In the field sequential drive, each color RGB image is projected onto the panel over time. To adjust the size of each color image, the magnification of the image when projecting each color image is changed over time. It is necessary to change with it.

Since the timing for changing the image size can be obtained from the synchronization signal of the original image, a synchronization signal for changing the image magnification is generated from the original image signal by the clock generation block, and the clock input to the magnification converter and the spatial light modulator is generated. Input and synchronize the magnification converter and the spatial light modulator.
If the timing does not match, a delay line is inserted between the magnification converter and the spatial light modulator, and the phases of the image signal and the magnification conversion timing are matched.

  The projector according to the present embodiment can also be implemented as a so-called three-plate liquid crystal projector using three RGB liquid crystal panels. In this case, the lateral chromatic aberration generated by the projection lens can be corrected by the size of the image projected on each color panel, and the projection lens having a large lateral chromatic aberration can be configured with a small number of lenses in anticipation of the correction effect, thereby reducing the cost. In addition, it is possible to compensate for the misalignment between the color panels using this method.

  In addition, the projector according to the present embodiment can be implemented as a so-called field sequential drive single-panel liquid crystal projector or a projector using an RGB spatial division filter. In this case, in particular, in the projector configuration using the RGB spatial division filter, the effect of sub-pixel shift correction is great because the pixels of each color are originally shifted. Further, for example, a projector using a self-luminous panel in which a spatial light modulator and a light source are integrated, such as an RGBLED array type projector using minute LEDs for each pixel, is also possible.

  In the case where the projection optical system is configured by combining a light source with a single wavelength light source such as an RGB LED, for example, a magnification adjuster that performs magnification chromatic aberration correction may be provided and adjusted for each color. In this way, when projecting a minute white spot, it is separated into three points on the screen with three single wavelengths, but each point can be adjusted so that the three points overlap one point with each magnification adjuster. A lateral chromatic aberration can be corrected.

The size along the predetermined direction of the plurality of projection screens projected by the plurality of color lights indicates the size of the projection screen in the vertical direction or the horizontal direction, and the size along at least one of the vertical and horizontal directions is the size of each color. A spatial light modulator is provided with a magnification converter for adjusting the size of the image signals of the respective colors inputted in different spatial light modulators along a predetermined direction, that is, at least one of the vertical and horizontal directions, so that both sizes are aligned. Set the enlargement or reduction ratio of the magnification converter.
Further, the vertical direction and the horizontal direction may be adjusted simultaneously. In addition to the above, the size along the predetermined direction may be a diagonal direction of the projection image, or may be a radius indicating a distance from the center and a circumferential direction orthogonal to the radius in the polar coordinate system.

[Operation example 2]
An example of the pixel arrangement is shown in FIG. FIG. 4 shows the RGB pixel arrangement in FIG. Each RGB pixel is displaced by a sub-pixel due to lateral chromatic aberration. In this state, by performing the processing of Patent Literature 4 and Non-Patent Literature 1 on an image to be displayed, high quality display with sub-pixel accuracy can be realized even in a projector.

  In addition, since chromatic aberration of magnification is used for the sub-pixel shift of each RGB pixel, depending on the type and angle of view of the projection lens, various RGB pixel arrangements as shown in FIG. 5 and FIG. The RGB shift amount for each angle of view or the projection position of the screen image with respect to the RGB component of each pixel of the projection image is stored as a table, and the above processing considering the shift amount is performed, so that highly effective subpixel accuracy is achieved. High quality display can be realized.

[Operation example 3]
Magnification aberration correction can be performed, and an image can be projected at a resolution higher than the panel resolution by utilizing the fact that subpixel shift occurs for each RGB color due to magnification aberration.
FIG. 7A shows a normal character not using subpixel shift, and FIG. 7B shows a character using subpixel shift. In particular, in the diagonal line, the normal character that does not use the sub-pixel shift as shown in FIG. 7 (a) looks rattling, whereas in the character using the sub-pixel shift shown in FIG. 7 (b), the diagonal line is smooth. Is displayed. This is because the characters in FIG. 7B are copied at a resolution higher than the resolution of the liquid crystal by utilizing the RGB sub-pixel shift within one pixel in the liquid crystal. Such a technique of drawing at a resolution higher than the resolution of the liquid crystal using subpixel shift is referred to as subpixel rendering.
When the character using the sub-pixel shift of FIG. 7B is enlarged, it can be confirmed that red or blue is displayed beside the line.

  In conventional anti-aliasing, jagged parts such as diagonal lines are expressed in neutral colors so that they appear smooth. For example, when white characters are displayed on a black background, the boundary between the characters and the background is drawn in an intermediate color between white and black, that is, gray (gray). At this time, gray is drawn with a plurality of gradations, and gently represents a change from white to black or from black to white.

  On the other hand, sub-pixel rendering is a technology that uses the “red (R)”, “green (G)”, and “blue (B)” sub-pixels of the display to express gradation and perform anti-aliasing. . Usually, one pixel of the display is composed of RGB sub-pixels. The light is transmitted (or emitted) through the RGB sub-pixels to express the color (white is obtained by transmitting / emitting the three colors of RGB). The high-quality display with sub-pixel accuracy is more smooth by controlling the gray portion in the conventional anti-aliasing to the sub-pixel level. Due to such a mechanism, a high-quality display with sub-pixel accuracy is most effective for a liquid crystal panel in which a pixel on the software and a pixel on the display correspond one-to-one.

  As is apparent from FIGS. 7 and 8, not only the on / off state of the sub-pixels but also RGB colors are expressed by several gradations (for example, five gradations). By correcting the gradation (luminance) level of each RGB color in consideration of the eye characteristics, it is possible to minimize the appearance of color misregistration and to make it appear smoother than the conventional rest aliasing. By controlling the gradation level, sub-pixel rendering works effectively even in a projector.

  Unlike conventional anti-aliasing, sub-pixel rendering performs processing such as dividing RGB into sub-pixels and leaving only the R component. With normal anti-aliasing, the font looks fat or appears to be blurred, but with sub-pixel rendering, control is done with a 1/3 pixel size, so the font can be drawn more smoothly and smoothly.

  In the sub-pixel rendering, color developing elements for generating the three primary colors of RGB, such as a liquid crystal display and a plasma display, are arranged in a first order in a predetermined order to form one pixel, and a plurality of pixels are arranged in the first direction. It is effective for a display screen configured by arranging a plurality of lines in a direction orthogonal to the first direction. In the case of the correction of chromatic aberration of magnification according to the present invention, the color developing elements for developing the respective colors are not arranged in the first direction in a fixed order from the beginning, but the projected image is caused by the chromatic aberration of magnification of the projection lens. Since the pixels of each color appear to be shifted from the center to the outside, it is the same as forming one pixel by arranging the pixels of each color in the peripheral portion of the projection image, and in the peripheral half of the projection image Great effect.

When an image with sub-pixel accuracy is displayed on the display screen as it is, a pixel (edge portion of the image) having a large difference compared to the surrounding pixels in the first direction is biased toward the luminance of the three color forming elements constituting the pixel. Color unevenness occurs. For this reason, in order to perform high-quality display with sub-pixel accuracy, it is necessary to apply a filtering process for flattening the surrounding sub-pixels and luminance to each sub-pixel.
In this method, the image data can be re-decomposed according to the wavelength of the light source to be decomposed, and the magnification can be changed according to the wavelength of each light source. When there are four colored lights of the light source, it can be decomposed into four lights and subjected to size conversion processing on the four images.

FIG. 15 shows a flow of a compensation method for lateral chromatic aberration generated in the projection system of the projector.
When the original image is input (step S101), the original image is separated into each color component (step S102), and the size in a predetermined direction (for example, the horizontal direction of the screen) is aligned with each color light for each color light. The enlargement magnification of the magnification converter is adjusted (step S103). When the coordinates of each pixel of the image of each color light are the same before and after conversion (step S104 / Yes), it is adopted as the luminance of that pixel of that color light as it is. If the coordinates of the pixels do not match (step S104 / No), the luminance value of the corresponding pixel is calculated by complementation from the luminance value of each adjacent color light pixel of the image before conversion (step S105). Various methods can be used as the complementing method, and any method may be used in the present invention. Color deviation data due to magnification chromatic aberration of the projection system is preliminarily applied to the image data for magnification chromatic aberration complementation thus obtained (step S106). If there is no color deviation (step S107 / No), an image corresponding to the result is obtained. Is projected on the screen (step S108).
It is determined whether there is a color shift at the center or the peripheral portion of the projected image. If there is a color shift (Yes in step S107), the magnification of the magnification converter is finely adjusted (step S103). If the enlargement magnification of the magnification converter is correct (if there is no color deviation), the projected image is compensated for the color deviation caused by the magnification chromatic aberration, and therefore the enlargement magnification adjustment process need not be performed.

  As described above, the projector according to the present embodiment adjusts the size of the image data input to the spatial light modulator in advance for each color light with the inverse characteristic of the chromatic aberration of the projection optical system, and includes a projection optical system including the chromatic aberration of magnification. After passing, the image data input on the projection screen can be reproduced, and the lateral chromatic aberration of the projection optical system is corrected by the data input to the spatial light modulator. Thereby, the color shift due to the magnification chromatic aberration of the projection optical system can be reduced.

  In addition, the said embodiment is an example of suitable implementation of this invention, This invention is not limited to this, A various deformation | transformation is possible.

It is a figure which shows the structure of the display screen of the conventional display apparatus. It is a figure which shows the state which piled up the pixel of each color favorably in the whole range of the screen. It is a figure which shows an example of pixel arrangement | positioning. It is a figure which shows an example of the pixel arrangement | positioning for 1 pixel. It is a figure which shows another example of the pixel arrangement | positioning for 1 pixel. It is a figure which shows another example of the pixel arrangement | positioning for 1 pixel. It is a figure which shows the difference of the character by the presence or absence of subpixel rendering. It is a figure which expands and shows the character which performed the subpixel rendering. It is a figure which shows the magnification chromatic aberration of a projection optical system. It is a figure which shows the principle of magnification chromatic aberration compensation of the projection optical system by a pre filter. It is a figure which shows the function structure of magnification chromatic aberration compensation of the projector concerning suitable embodiment of this invention. It is a figure which shows the structure of a pre filter. It is a figure which shows the structural example in the case of inputting the image to project directly to a spatial light modulator, without passing through a combiner. It is a figure which shows the example applied to the single-panel liquid crystal projector by a field sequential drive. It is a figure which shows the flow of the magnification chromatic aberration compensation process of the projector which concerns on preferable embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Prefilter 11 Decomposer 12 Magnification converter 13 Synthesizer 14 Spatial light modulator 15 Projection optical system 16 Clock generator

Claims (6)

A light source, a separation optical system that separates light emitted from the light source into a plurality of color lights, and a space corresponding to each color light for forming the image of each color according to the image signal of each color upon incidence of the plurality of color lights A projector having a light modulator, a color light combining optical system for combining the respective color lights emitted from the spatial light modulator, and a projection optical system for projecting the light combined by the color light combining optical system;
A magnification converter for adjusting a size of the image signal of each color input to the spatial light modulator along the predetermined direction; and a predetermined direction of the image of each color formed by each of the plurality of color lights A projector characterized by aligning the size along each color. Projection having a light source, a spatial light modulator for forming an image in accordance with an image signal upon incidence of light emitted from the light source, and a projection optical system for projecting an image formed by the spatial light modulator Machine,
A magnification converter for adjusting a size along a predetermined direction of each color image formed by the light emitted from the light source; and in a predetermined direction of each color image formed by each of the plurality of color lights A projector characterized by aligning the size along each color. The color light of the light source is three colors of red, blue and green,
The magnification converter has the predetermined direction of the image signal of each color to be input to the spatial light modulator so that the sizes along the predetermined direction of the projection screen projected by the three colors of color light match each color. The projector according to claim 2, wherein the size of the projector is adjusted.   4. The projector according to claim 1, wherein an enlargement magnification in the magnification converter is larger for a color light having a longer wavelength. 5.   The predetermined direction of the reference projection image obtained by the reference image signal projection means and further provided with a reference image signal projection means and a projection image detection means for projecting a reference projection image. The projector according to any one of claims 1 to 4, wherein a size along each of the colors is aligned between the colors. The size along the predetermined direction of the image signal of each color input to the spatial light modulator is adjusted so that the sizes along the predetermined direction of the plurality of projection screens projected by the plurality of color lights are aligned between the colors. Magnification conversion process;
Complement value calculation that calculates the luminance value of the corresponding pixel by complementation from the luminance value of each adjacent color light pixel of the image before conversion when the coordinates of each pixel of the image of each color light do not match before and after conversion A process,
The method for compensating for chromatic aberration of magnification of a projector, wherein, in the complementary value calculating step, complementation is performed using an intermediate value of luminance of each pixel of each color light, and gradation is adjusted for each color.

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