JP4572066B2 - projector - Google Patents

Description

  The present invention relates to a projector that projects image data on a screen such as a personal computer, a camera, or a television, and in particular, projects a test pattern on the screen and reads the image of this test pattern to correct distortion of the projected image, autofocus, etc. The present invention relates to a projector that performs processing.

  In recent years, liquid crystal projectors and DLP (Digital Light Processing) projectors are compact and lightweight devices that are excellent in portability, so that their use in various scenes is rapidly increasing.

  Unlike a stationary CRT projector, such a portable projector is supposed to be displayed in an environment in which the positional relationship between the screen and the projector is changed. In this case, it is necessary to adjust the image according to the positional relationship between the screen and the projector. Specifically, it is necessary to adjust the screen size and focal length according to the distance between the screen and the projector. In addition, it is necessary to correct the screen shape according to the inclination and curvature of the screen.

Conventionally, when performing autofocus and image distortion correction as described above, the test pattern is projected onto the screen with red, green, and blue light, and the test pattern (projected image) on the screen is imaged. The pattern was analyzed based on a known test pattern, and the focal length and image distortion were corrected (for example, refer to Patent Documents 1 and 2).
JP 2000-28901 A (see paragraph numbers [0002] to [0003]) Japanese Patent No. 2538435

  However, since the test pattern image is originally an unnecessary image and is an image of R, G, and B visible light, when projected onto the screen, the original image is not visually recognized and is troublesome.

  For this reason, when the projected test pattern is used for autofocus and image distortion correction processing, the display of the video by the input signal is stopped and only the test pattern is displayed on the screen.

  Therefore, with a conventional projector, it is impossible to always perform autofocus and image distortion correction using a test pattern while displaying an original video.

  An object of the present invention is to provide a projector that can always perform autofocus and image distortion correction processing using a test pattern while displaying an image based on an input signal in view of the above-described problems of the prior art. .

In order to achieve the above object, a projector according to the present invention includes a light source that emits white light,
An invisible light removal filter on which white light from the light source is incident;
A color wheel that rotates through the light that has passed through the invisible light removal filter, and
Image forming means for reflecting the light passing through the color wheel to form a dot matrix type image;
A projection lens for enlarging and projecting an image formed by the image forming means on a screen;
A condensing lens that condenses the image projected on the screen;
An invisible light transmission filter that allows only invisible light to pass through the image collected by the condenser lens;
An image sensor that captures an image of invisible light that has passed through the invisible light transmission filter,
The invisible light removal filter has an invisible light transmitting portion that transmits the test pattern so that the image has an image having a test pattern including invisible light.
The outer peripheral portion of the color wheel has a red transmission portion that transmits red of the three primary colors of light, a green transmission portion that transmits green of the three primary colors of light, and a blue transmission that transmits blue of the three primary colors of light. And one of the red transmissive part and the blue transmissive part also transmits invisible light.

  In the configuration as described above, white light from the light source enters the rotating color wheel via the invisible light removal filter. The image forming means reflects the light passing through the color wheel to form a dot matrix type color image. The reflected color image is projected on the screen by the projection lens. When the red transmission part of the color wheel is a part that also transmits invisible light, the invisible light of the invisible light removal filter is displayed on the color image on the screen when the light passing through the invisible light removal filter passes through the red transmission part. Invisible light transmitted through the transmission part is included. The color image on the screen is collected by a condenser lens, passes through an invisible light transmission filter, and an image of invisible light is picked up by an image sensor.

  Based on the invisible light image picked up by the image pickup device, autofocus processing can be performed, or image distortion correction processing can be performed.

  The invisible light removing filter preferably has a pattern composed of a plurality of the invisible light transmitting portions. The image forming means can apply DMD. The invisible light can be infrared light or ultraviolet light.

  According to the present invention, while projecting a color image on a screen, a test pattern is projected by invisible light typified by infrared light or ultraviolet light, and the invisible light is captured by an image sensor, thereby using the test pattern. Processing such as autofocus and image distortion correction can be performed.

  Furthermore, in the present invention, an infrared light removal filter having a plurality of invisible light transmitting portions formed as a test pattern is disposed between the light source and the color wheel, and the red color in the color region in which the outer periphery of the color wheel is divided into three as usual. Either one of the transmissive part and the blue transmissive part was made an area that also transmits invisible light. With this configuration, three images (red (R) image including infrared, green (G) image, blue (B) image) including three images are synthesized in the same manner as a conventional DLP projector using a color wheel. Since it can be configured as a single color image, it is possible to project a test pattern using infrared light without significantly reducing the video luminance as compared with a DLP projector using a conventional color wheel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a schematic configuration of a DLP projector according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an infrared light removal filter shown in FIG. 1, and FIG. 3 is a configuration of a color wheel shown in FIG. FIG.

  Referring to FIG. 1, a projector 10 according to this embodiment includes a light source 1 such as a high-pressure mercury lamp that emits white light, an infrared light removal filter 2 on which white light from the light source 1 is incident, and an infrared light removal filter 2. The color wheel 3 on which the light passed through, the color light passing through the color wheel 3 periodically enters, DMD4 which is an image forming means for forming a dot matrix type image, and the image formed by the DMD4 are screened A projection lens 5 for enlarging and projecting the image onto the screen 9, a condensing lens 6 for condensing the image projected on the screen 9, and an infrared light transmission filter 7 for passing only infrared light out of the light passing through the condensing lens 6. And an image pickup device 8 such as a CCD for picking up an image of infrared light passing through the infrared light transmission filter 7.

  Although not shown, a converging lens is disposed in the optical path between the light source 1 and the color wheel 3 and between the color wheel 3 and the DMD 4.

  The screen 9 is installed at a position away from the projector 10.

  The projection lens 5 and the condenser lens 6 are arranged at a position facing the screen 9.

  The color wheel 3 is a disk-shaped color filter that is driven to rotate.

  The DMD 4 is provided with micron-sized micromirrors tilted to ± 10 degrees according to ON / OFF of an input signal based on image data, which is spread over hundreds of thousands to millions. Each micromirror switches (on / off) reflected light toward the screen based on the image data, thereby forming a projection image. By making white light from the light source enter the DMD 4 through the rotating color wheel, the projected image becomes a color. At this time, one micromirror is in charge of one pixel of the projected image, and takes charge of each color of R, G, and B in a time division manner. For example, in order to display a color image of 60 frames per second, the color wheel is rotated at a period three times that, and R, G, and B are displayed in a time-sharing manner. That is, R, G, and B images are projected onto the screen in 1/180 second units. In this case, the actual color composition is processed by the human brain. Note that image data serving as an input signal to the DMD 4 is output from a personal computer, digital video, or the like.

  In the present invention, an infrared light removal filter 2 is disposed between the color wheel 3 disposed on the optical path from the light source 1 to the DMD 4 and the light source 1.

  As shown in FIG. 2, the infrared light removal filter 2 has five infrared light transmission parts 22 for displaying five spots as test patterns on the screen 9, and the infrared light transmission part 22 other than the infrared light transmission part 22 is red. This is an infrared light non-transmissive portion 21 that does not allow external light to pass through. The infrared light transmitting portion 22 is a portion that transmits light including infrared light from the light source 1.

  The color wheel 3 of the present invention is disposed on the optical path from the infrared light removal filter 2 to the DMD 4. The outer periphery of the rotating color filter 3 crosses this optical path. As shown in FIG. 3, the outer periphery of the color filter 3 transmits red (R) of the three primary colors of red (R), green (G), and blue (B), and also transmits infrared light. , The infrared and red transmission part 31, the green transmission part 32 that transmits green (G), and the blue transmission part 33 that transmits blue (B).

  Next, the operation of the projector of the present invention will be described with reference to FIGS. FIG. 4 is a diagram for explaining the operation of the projector of FIG.

  Of the white light from the light source 1, most of the infrared light is removed by the infrared light removal filter 2, and the infrared light is transmitted through the infrared light transmission part 22 of the infrared light removal filter 2.

  The light that has passed through the infrared light removal filter 2 enters the DMD 4 through the color wheel 3. At this time, the light incident on the color wheel 3 includes infrared light transmitted through the plurality of scattered infrared light transmitting portions 22 of the infrared light removing filter 2. Since the color wheel 3 is rotating, light including red (R) and infrared light, green (G) light, and blue (B) light periodically enter the DMD 4.

  The light transmitted through the color wheel 3 is reflected by the DMD 4 and is projected on the screen 9 outside the projector as a color image.

  When processing such as autofocus and image distortion correction is not performed (normal time), an image 101 reflected and projected onto the screen 9 is formed on the panel of the DMD 4 as shown in FIG.

  Processing such as autofocus and image distortion correction is performed during a period in which the light passing through the infrared light removal filter 2 passes through the infrared and red transmission portions 31 of the color wheel 3. During this period, an image 102 reflected and projected on the screen 9 as shown in FIG. 4B is formed on the panel of the DMD 4. Such video is formed based on image data from an input unit such as a personal computer or digital video.

  In FIG. 4B, the portion in which the white spot 102a is drawn in the black display is irradiated with infrared light transmitted through the infrared light transmitting portion 22 of the infrared light removal filter 2. In addition to the above, infrared light is not irradiated by the infrared light non-transmissive portion 21 of the infrared light removal filter 2. When attention is paid only to the infrared light transmitted through the infrared light transmission part 22 of the infrared light removal filter 2, spots (whitened portions in the figure) as shown in FIG. It is projected.

  Therefore, the image projected on the screen 9 during this period is collected by the condenser lens 6, and only the infrared light in this image passes through the infrared light transmission filter 7 and is imaged on the image sensor 8. A plurality of spot-like infrared lights are scattered on the image sensor 8 to form a test pattern. In the present embodiment, a test pattern is formed by five spots indicated by reference numeral 102a in FIG. The configuration of the test pattern is not limited to this embodiment, and it may be a test pattern such as a rectangle, a grid, or a combination of vertical and horizontal lines.

  Processing such as autofocus and image distortion correction is performed using the test pattern input to the image sensor 8.

  When performing autofocus, for example, the distance to the screen 9 is measured based on a test pattern imaged by the image sensor 8, and the focus of the projection lens 9 is adjusted based on the distance measurement data (by the applicant). (See Japanese Patent Application No. 2003-303826 for which it was filed)

  When image distortion correction is performed, for example, a test pattern composed of a plurality of points is used, and the inclination angle between the straight line connecting the points imaged by the image sensor 8 and the reference line is analyzed from the imaging screen of the image sensor 8. Then, the tilt angle between the optical axis of the projection lens 5 and the screen 9 is calculated from the tilt angle, and the image distortion on the screen 9 is corrected by controlling the output video according to the calculated tilt angle (by the applicant). (See Japanese Patent Application No. 2003-143501 filed).

  In this way, while displaying a color image on the screen 6, autofocus and image distortion correction are performed while the light passing through the infrared light removal filter 2 passes through the infrared and red transmission portions 31 of the color wheel 3. Etc. can be implemented.

  Although the DLP projector is shown in the present embodiment, the present invention can be applied to a projector using a dot matrix display (lattice display) such as a liquid crystal panel. For example, in the configuration shown in FIG. 1, by replacing the DMD 4 with a reflective liquid crystal panel, it is possible to perform processing such as autofocus and image distortion correction using a test pattern in the same manner as described above.

  Moreover, although the structural example which uses infrared rays for the display of a test pattern was shown, what is necessary is just to use invisible light which does not disturb the visual recognition of the image on a screen, and it can apply also with ultraviolet rays. In the case of the DLP projector of FIG. 1, the infrared and red transmission parts 31 are replaced with red transmission parts, the blue transmission part 33 is replaced with ultraviolet and blue transmission parts, and the outer periphery of the color wheel 3 is divided into three parts. It can be considered that the infrared light removal filter 2 is replaced with an ultraviolet light removal filter, and the infrared light transmission filter 7 is replaced with an ultraviolet light transmission filter that passes only ultraviolet light. Specifically, the red transmitting portion of the color wheel 3 is an area that transmits blue (B) of the three primary colors of red (R), green (G), and blue (B), and the ultraviolet and The blue transmission part is an area that transmits blue (B) and also transmits ultraviolet light. The ultraviolet light removal filter has five ultraviolet light transmission parts for displaying a plurality of spots as test patterns on the screen 9, and is an ultraviolet light non-transmission part that does not transmit ultraviolet light other than the ultraviolet light transmission part. The ultraviolet light transmitting portion is a portion that transmits light including ultraviolet light from a white light source.

  However, since ultraviolet rays and far infrared rays may cause an increase in temperature, it is preferable to use near infrared rays for test pattern display as much as possible.

1 is a diagram showing a schematic configuration of a DLP projector according to an embodiment of the present invention. It is a block diagram of the infrared light removal filter shown in FIG. It is a block diagram of the color wheel shown in FIG. It is a figure for demonstrating the effect | action of the projector of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Infrared light removal filter 3 Color wheel 4 DMD
5 Projection lens 6 Condensing lens 7 Infrared light transmission filter 8 Image sensor 9 Screen 21 Infrared light non-transmission part 22 Infrared light transmission part 31 Infrared and red transmission part 32 Green transmission part 33 Blue transmission part 101, 102 Video 102a White spot

Claims (6)

A light source that emits white light;
An invisible light removal filter on which white light from the light source is incident;
A color wheel that rotates through the light that has passed through the invisible light removal filter, and
Image forming means for reflecting the light passing through the color wheel to form a dot matrix type image;
A projection lens for enlarging and projecting an image formed by the image forming means on a screen;
A condensing lens that condenses the image projected on the screen;
An invisible light transmission filter that allows only invisible light to pass through the image collected by the condenser lens;
An image sensor that captures an image of invisible light that has passed through the invisible light transmission filter,
The invisible light removal filter has an invisible light transmitting portion that transmits the test pattern so that the image has an image having a test pattern including invisible light.
The outer peripheral portion of the color wheel has a red transmission portion that transmits red of the three primary colors of light, a green transmission portion that transmits green of the three primary colors of light, and a blue transmission that transmits blue of the three primary colors of light. A projector in which either the red transmission part or the blue transmission part also transmits invisible light. The projector according to claim 1, wherein the image forming unit is a DMD. The projector according to claim 1, wherein the invisible light removal filter has a pattern configured by a plurality of the invisible light transmission units. The projector according to claim 3, wherein an autofocus process is performed based on a pattern image of invisible light imaged by the image sensor. The projector according to claim 3 or 4, wherein an image distortion correction process is performed based on a pattern image of invisible light imaged by the image sensor. The projector according to claim 1, wherein the invisible light is infrared light or ultraviolet light.

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