JP2008165077A - Image projection device - Google Patents

Abstract

An image projection apparatus capable of displaying an image that can be viewed by a person who is permitted to be viewed and that is difficult for other persons to view.
An image projecting device (10) projects a first image on a screen (32) so that the image projected on the screen (32) is a second image different from the first image. Generate three images. The image projecting device 10 causes the second image to be displayed on the screen 32 so as to be visible by projecting the first image and the third image at least with different polarization characteristics or time-divisionally and projecting them. The glasses 18 extract the first image from the second image so as to be visible.
[Selection] Figure 4

Description

  The present invention relates to an image projection apparatus, and more particularly to an image projection apparatus that displays a predetermined image by projecting light onto a projection plane.

  Conventionally, an image projector includes a projector that projects light onto a projection surface and displays a predetermined image. Such an image projection apparatus such as a projector includes a light source that emits light, a control unit that controls the light source, and the like.

Specifically, an image projection apparatus incorporating an electro-optical element such as a liquid crystal display device or a DMD (Digital Micromirror Device) display element has become widespread. This type of image projection apparatus is easy to carry. For example, as disclosed in Patent Document 1, a portable device such as a mobile phone having excellent portability is provided with a projection unit that projects light. Therefore, it is possible to display a large image so as to be visible with a small device, which is convenient.
JP 2003-235037 A

  However, in the image projection apparatus as described above, it is preferable that the user himself / herself visually recognizes the displayed image, but that a person who does not want to visually recognize the image causes a privacy problem or a leakage of personal information. It can be. In addition, for example, a hologram screen can be adopted as the projection surface, but the viewing angle of the image of a person such as a user who wants to visually recognize changes slightly, which makes the image difficult to visually recognize and may be expensive. There was also.

  The present invention has been made in view of the above-described problems, and provides an image projection device capable of displaying an image that is visible to a person who is allowed to be visually recognized and difficult for other people to visually recognize. The purpose is to do.

  In order to achieve the above object, the present invention provides the following.

  That is, according to the first aspect of the present invention, in the image projection apparatus that displays a predetermined image by projecting light onto a projection surface, the projection is performed by projecting the first image onto the projection surface in an overlapping manner. An image generation unit that generates a third image for making the image projected on the surface a second image different from the first image, and the first image and the third image at least Projecting the second image so that the second image can be viewed on the projection surface by overlapping and projecting with different polarization characteristics or time division, and the first image can be viewed from the second image And an image extracting unit for extracting the image.

  According to a second aspect of the present invention, in the first aspect of the present invention, the image extraction unit is arranged in front of the eyes of the viewer.

  Further, in the present invention described in claim 3, in the invention described in claim 1 or 2, the second image is a still image.

  According to a fourth aspect of the present invention, in the third aspect of the invention, the second image is a homogeneous white image.

  Further, in the present invention described in claim 5, in the invention described in claim 3, the second image is a predetermined pattern or an image of a predetermined pattern.

  Further, in the present invention according to claim 6, in the invention according to any one of claims 1 to 5, each pixel of the third image is a complementary color of a corresponding pixel of the first image. It is a feature.

  Moreover, in this invention of Claim 7, in the invention in any one of Claim 1-6, the said projection part superimposes said 1st image and said 3rd image as a different polarization characteristic. It has the function to project.

  In the present invention described in claim 8, in the invention described in claim 7, the projection unit includes a first light corresponding to the first image and a third light corresponding to the third image. It is characterized by having an optical system that emits light in a time-division manner.

  Further, in the present invention according to claim 9, in the invention according to claim 8, the optical system includes: a light source that emits light; and a light modulation element that modulates light from the light source and emits image light. A movable body provided with a plurality of regions that emit light from the light source as different polarization characteristics and transmit the light as a predetermined color, and a movable control unit that performs displacement control of the movable body, The movable control unit performs a control for displacing the movable body, whereby a first light corresponding to the first image modulated by the light modulation element and a third light corresponding to the third image. It has a function of overlapping and projecting light with different polarization characteristics in a time-sharing manner.

  According to a tenth aspect of the present invention, in the eighth aspect of the invention, the optical system includes a light source that emits light of a predetermined color and a light source that modulates the first light. A light modulation element that emits the light of the light and the third light in a time-sharing manner, and a polarizing plate that emits the light from the light source as different polarization characteristics, and the polarizing plate is formed by the light modulation element. The first light corresponding to the first image modulated in a time division manner and the third light corresponding to the third image have a function of overlapping and projecting as different polarization characteristics, To do.

  The invention according to claim 11 is the invention according to any one of claims 1 to 10, further comprising a communication unit that transmits or receives a synchronization signal between the projection unit and the image extraction unit. It is characterized by this.

  According to invention of Claim 1 or 2, the 3rd image for making the image projected on a projection surface into a 2nd image by superimposing on a projection surface and a 1st image is made into a 2nd image. Generating the first image and the third image at least as different polarization characteristics or by time-sharing and projecting the second image so as to be visible on the projection plane, A first image is extracted from the first image so as to be visible. Accordingly, the second image can be displayed in a visible manner, and the first image can be displayed in a visible manner by extracting the first image from the second image. It is possible to display an image that becomes visible and is difficult for other people to see.

  According to the invention described in claim 3, the second image is a still image. Therefore, it becomes easy to generate the third image.

  According to the invention described in claim 4, the second image is a homogeneous white image. Therefore, it becomes easy to generate the third image. In addition, the second image is the most natural image with no sense of incongruity.

  According to the invention described in claim 5, the second image is a predetermined pattern or an image of a predetermined pattern. Therefore, it becomes easy to generate the third image.

  According to the invention described in claim 6, each pixel of the third image is a complementary color of the corresponding pixel of the first image. Therefore, it becomes easy to generate the third image.

  According to the seventh aspect of the present invention, the first image and the third image are projected as different polarization characteristics. Therefore, it is easy to extract the first image. When the image extraction unit extracts the first image, the first image can be visually recognized. When the image is not extracted, the second image can be displayed. It is possible to display an image that is visible to a person who is permitted to view the image and is difficult for other persons to view.

  According to the eighth aspect of the present invention, the optical system includes the first light corresponding to the first image and the third light corresponding to the third image which are emitted in a time-division manner. It was. Therefore, it is easy to extract the first image. When the image extraction unit extracts the first image, the first image can be visually recognized. When the image is not extracted, the second image can be displayed. It is possible to display an image that is visible to a person who is permitted to view the image and is difficult for other persons to view.

  According to the ninth aspect of the present invention, the light source that emits light, the light modulation element that modulates the light from the light source to emit the image light, and the light from the light source are emitted as different polarization characteristics. And a movable body provided with a plurality of regions that transmit as a predetermined color, and by performing control to displace the movable body, the first corresponding to the first image modulated by the light modulation element The light and the third light corresponding to the third image are projected in a time-sharing manner with different polarization characteristics. Therefore, even if there is only one light source, it can be transmitted not only as a predetermined color but also with different polarization characteristics due to displacement of the movable body, and various images such as color images can be simplified even without a plurality of light sources. Can be displayed.

  According to the invention of claim 10, the first light and the third light are emitted in a time division manner by modulating the light from the light source that emits light of a predetermined color and the light source. A polarizing plate that emits light from the light source as different polarization characteristics, and the polarizing plate includes first light corresponding to the first image modulated in a time division manner by the light modulating device; The third light corresponding to the third image is projected as different polarization characteristics. Therefore, by using the polarizing plate, the first light and the third light can be easily emitted as different polarization characteristics.

  According to the invention described in claim 11, the communication unit that transmits or receives the synchronization signal between the projection unit and the image extraction unit is provided. Therefore, since the projection unit and the image extraction unit are synchronized, even when polarization is not performed, the first image can be visually recognized only when time-division is extracted by the image extraction unit. If not extracted, the second image can be displayed so that it can be viewed, and a person who is allowed to view can be viewed, and an image that is difficult for other people to view can be displayed.

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

[Configuration of image projection apparatus]
An overview of the image projection apparatus according to the present embodiment will be described with reference to FIG.

  The image projection device 10 is a device that displays a predetermined image by projecting image light onto a projection surface. As shown in FIG. 1, the image projection device 10 includes a main body 12, an emission unit 14 that emits image light from the main body 12, and a control panel 16 that performs a control operation of the image projection device 10. It is configured. The main body unit 12 incorporates an optical system 20 (see FIG. 2) for projecting image light. By modulating light from the light source, image light is generated and guided to the emitting unit 14. The emitting unit 14 emits the image light generated in the main body unit 12 and projects the image light onto the projection surface, thereby displaying a predetermined image based on the image light.

[Configuration of projection optical system]
The optical system built in the main body 12 will be specifically described with reference to FIG.

  As shown in FIG. 2, the optical system 20 includes red, blue, and green light sources 22R, 22G, and 22B, and an illumination optical system 24 that guides illumination light from the light sources 22R, 22G, and 22B to the light modulation element 26. A light modulation element 26 irradiated with illumination light guided by the illumination optical system 24, and a polarizing plate 28 that polarizes light between the illumination optical system 24 and the light modulation element 26, and whose polarization characteristics can be switched. And an imaging optical system 30 such as a projection lens that projects the on-light from the light modulation element 26 as image light toward a screen (projection surface) 32. The screen 32 is preferably a screen with little light diffusion.

  Red, blue, and green LEDs (Light Emitting Diodes) are employed as the light sources 22R, 22G, and 22B, and the light modulation element 26 is illuminated through the illumination optical system 24, respectively. That is, in the present embodiment, the light sources 22R, 22G, and 22B emit light of a predetermined color such as red, blue, and green.

  The illumination optical system 24 is a lens 24R, 24G, 24B for condensing the light illuminated from each of the three light sources 22R, 22G, 22B, and the light illuminated from each of the two light sources 22G, 22B. Mirrors 24 </ b> A and 24 </ b> C that reflect toward the modulation element 26 are included. The mirror 24A transmits the light from the light source 22R and reflects the light from the light source 22G, and the mirror 24C transmits the light from the light sources 22R and 22G and reflects the light from the light source 22B.

  As the light modulation element 26, a DMD display element is employed. This light modulation element 26 has two-dimensionally arranged fine micromirrors on a semiconductor substrate, and controls the change of the tilt angle of each micromirror according to the image signal, thereby changing the incident light in two different directions. And only the reflected light in one direction is formed as image light. That is, the light modulation element 26 modulates the light from the light sources 22R, 22G, and 22B in accordance with the image signal and emits video light.

  The polarizing plate 28 has a function of polarizing light from the light sources 22R, 22G, and 22B. Moreover, the polarizing plate 28 is comprised by the liquid crystal element etc., for example, The polarization characteristic is controlled so that switching is possible. In particular, the polarizing plate 28 can switch the polarization characteristics in the vertical direction. Since the polarization characteristics can be switched in this way, the first image can be extracted and displayed by displaying the first image and the third image with different polarization characteristics, as will be described in detail later. It becomes. That is, the polarizing plate 28 emits light from the light sources 22R, 22G, and 22B as different polarization characteristics. In addition, the polarizing plate 28 projects the first light corresponding to the first image and the third light corresponding to the third image as different polarization characteristics.

[Electrical configuration of image projection apparatus]
FIG. 3 is a block diagram showing a control circuit of the image projection apparatus 10 in this embodiment.

  As shown in FIG. 3, the image projection apparatus 10 includes a control unit 42, a control panel 16, a video signal input circuit 44, a light source control circuit 46, an image processing circuit 48, a light modulation element drive circuit 50, a polarizing plate drive circuit 52, The light sources 22R, 22G, and 22B, the illumination optical system 24, the light modulation element 26 that is a light modulation element, the polarizing plate 28, and the imaging optical system 30 are included.

  The control unit 42 includes a CPU, a ROM (read only memory), a RAM (read / write memory), and the like, and has a function of controlling the entire image projection apparatus 10. In particular, when the control unit 42 displays an image in accordance with an operation signal from the control panel 16, the light source control circuit 46 causes the light source control circuit 46 to emit light sources 22R and 22G for each color at a predetermined cycle (for example, 1/180 seconds). , 22B are instructed to emit light instead. In addition, when the control unit 42 displays the first image and the third image with different polarization characteristics according to the operation signal from the control panel 16, the control unit 42 causes the polarizing plate drive circuit 52 to display the polarizing plate 28. And an instruction to switch the polarization characteristic in the vertical direction at a predetermined cycle (for example, 1/60 seconds). The control unit 42 also instructs the image processing circuit 48 to display an image, and a synchronization instruction to synchronize with the light emission timings of the light sources 22R, 22G, and 22B and the switching timing of the polarizing plate 28.

  The control panel 16 has a function of supplying an operation signal to the control unit 42 according to the operation of the operator.

  The video signal input circuit 44 is a circuit that receives a video signal input from the outside of the image projector 10 and outputs the video signal to the image processing circuit 48.

  The image processing circuit 48 is a circuit that performs image processing based on the video signal from the video signal input circuit 44 in response to an instruction from the control unit 42. In particular, the image processing circuit 48 controls the screen 32 to display an image by supplying various instruction signals to the light modulation element drive circuit 50.

  The image processing circuit 48 has a memory for storing image data, and stores a first image based on the received video signal for each frame (for example, every 1/30 seconds). A specific example of the first image corresponds to an image in which a crescent moon is rising in the night sky as shown in FIG. Further, the memory in the image processing circuit 48 stores second image data in advance. This second image data corresponds to a homogeneous white still image as shown in FIG.

  The image processing circuit 48 generates a third image based on the first image based on the input video signal and the second image stored in advance. As shown in FIG. 4, the third image is an image for displaying the second image so as to be visible by being displayed in time division with the first image, and the complementary color corresponding to the first image. It becomes. Specifically, as shown in FIG. 5, each pixel of the third image includes each color component (red component, green component, blue component) in each pixel of the second image, and the first image. This is the difference between the color components in each pixel, and the image light based on the first image data and the image light based on the third image data are projected in a time-sharing manner at a predetermined period (for example, 1/60 seconds). Thus, the image light based on the second image data is displayed so as to be visible. That is, the image processing circuit 48 superimposes and projects the first image on the screen 32 (projection surface), thereby making the image projected on the screen 32 a second image different from the first image. Therefore, a third image is generated. By generating in this way, it becomes easy to generate the third image. In addition, the second image is the most natural image with no sense of incongruity. In the present embodiment, the image processing circuit 48 that executes such processing corresponds to an image generation unit.

  Further, the image processing circuit 48 gives an instruction to control the light modulation element 26 in accordance with the first image data based on the first image and the third image data based on the third image. Accordingly, when the first image and the third image are displayed with different polarization characteristics and time-divisionally superimposed, the first image and the third image are displayed within a predetermined period (for example, 1/60 seconds). The display instruction based on the image data and the display instruction based on the third image data are alternately performed.

  The light modulation element drive circuit 50 performs drive control of the light modulation element 26 in response to an instruction from the image processing circuit 48. In particular, the light modulation element drive circuit 50 performs the control based on the first image data and the third image data within a predetermined period (for example, 1/60 seconds) in accordance with an instruction from the image processing circuit 48. The control based on is performed alternately. Thereby, the light modulation element 26 emits the first light and the third light in a time division manner by modulating the light from the light source.

  The light source control circuit 46 controls the light sources 22R, 22G, and 22B according to an instruction from the control unit 42, such as control for causing the light sources 22R, 22G, and 22B of each color to emit light at a predetermined period (for example, 1/180 seconds). Light emission control is performed.

  The polarizing plate drive circuit 52 operates the polarizing plate 28 in accordance with an instruction from the control unit 42 and performs control to switch the polarization characteristics in the vertical direction within a predetermined period (for example, 1/60 seconds). That is, the polarizing plate 28 emits light from the light sources 22R, 22G, and 22B as different polarization characteristics. In addition, the polarizing plate 28 projects the first light corresponding to the first image and the third light corresponding to the third image as different polarization characteristics.

  As described above, the irradiation light emitted from the light sources 22R, 22G, and 22B in a time-sharing manner is controlled by the control unit 42, the light source control circuit 46, the image processing circuit 48, the light modulation element drive circuit 50, and the polarizing plate drive circuit 52. As a first light corresponding to the first image data and a third light corresponding to the third image data, the light modulation element 26, the polarizing plate 28, etc. emit different polarization characteristics and as time division. Will be. Further, the first light and the third light are projected by the illumination optical system 24 and the imaging optical system 30 so that the second image is displayed on the screen 32 so as to be visible. . The optical system 20 including the light sources 22R, 22G, and 22B, the illumination optical system 24, the light modulation element 26, the polarizing plate 28, and the imaging optical system 30 differs at least between the first image and the third image. As the polarization characteristic, the second image is displayed on the screen 32 so as to be visible by time-division and overlapping projection. In the present embodiment, such an optical system 20 corresponds to a projection unit.

  The first image and the third image thus displayed on the screen 32 in a time-sharing manner (for example, 1/60 seconds) can be visually recognized as the second image. For example, FIG. As shown, the first image is visibly extracted from the second image by using the glasses 18 that transmit only the polarization characteristics in the first image, and the first image is not the second image. It can be visually recognized as an image. Accordingly, the second image can be displayed on the screen 32 so as to be visible, and the first image can be displayed so as to be visible by extracting the first image from the second image using the glasses 18 or the like. A person who is allowed to visually recognize can be visually recognized, and an image that is difficult for other persons to visually recognize can be displayed. Moreover, it becomes easy to extract a 1st image in such a structure. Moreover, by using the polarizing plate 28, the first light and the third light can be easily emitted as different polarization characteristics. In the present embodiment, such glasses 18 correspond to an image extraction unit disposed in front of the eyes of the viewer.

  In the above-described embodiment, the polarizing plate 28 is disposed between the light source and the light modulation element. However, the present invention is not limited to this. For example, the polarizing plate 28 is disposed between the imaging optical system and the screen. Also good.

[Second Embodiment]
In the above-described embodiment, by using the three light sources 22R, 22G, and 22B and the polarizing plate 28, the first image and the third image are time-divided with different polarization characteristics. However, the present invention is not limited to this. For example, a configuration using one light source may be used.

  A specific embodiment will be described with reference to FIGS. In addition, the description for facilitating understanding of the same configuration as the above-described embodiment is omitted.

  As shown in FIG. 7, the image projection apparatus 10 includes a single light source 22, a light pipe 62 that guides light emitted from the light source to the color wheel 60, and light emitted from the light pipe 62. A color wheel 60 having a transmissive region, an illumination optical system 24 that guides light through the color wheel 60 to the light modulation element 26, a light modulation element 26 that is irradiated with illumination light guided by the illumination optical system 24, and light And an imaging optical system 30 such as a projection lens that projects on-light from the modulation element 26 as image light toward a screen (projection surface) 32.

  The color wheel 60 is controlled to be rotatable about a rotation axis. As shown in FIG. 8, the color wheel 60 is divided into six transmission regions. These six transmission regions have polarization characteristics in a predetermined direction, a region 60RA that transmits red light, a region 60GA that transmits green light, a region 60GB that transmits blue light, and a polarization property that is perpendicular to the predetermined direction. And includes a region 60RB that transmits red light, a region 60GB that transmits green light, and a region 60GB that transmits blue light. Therefore, by rotating the color wheel 60, it is possible to display a color image, and the polarization characteristics of the first image and the third image are switched and displayed with different polarization characteristics in an overlapping manner. It becomes. That is, the color wheel 60 corresponds to a movable body provided with a plurality of regions that emit light from the light source 22 as different polarization characteristics and transmit the light as a predetermined color. Further, as shown in FIG. 8, in accordance with the rotational displacement of the color wheel 60, toward the center (rotation axis) of the color wheel 60, a predetermined direction (horizontal direction), and the predetermined direction is a vertical direction (vertical direction). Is set to the polarization characteristic.

  Further, as shown in FIG. 9, the image projection apparatus 10 is provided with a color wheel drive circuit 54 that controls the rotation drive of the color wheel 60. The color wheel drive circuit 54 controls the rotation of the color wheel 60 at a predetermined cycle (for example, one rotation at 1/30 seconds) in accordance with an instruction from the control unit 42. That is, the color wheel drive circuit 54 performs the control to displace the color wheel 60, whereby the first light corresponding to the first image modulated by the light modulation element 26 and the first light corresponding to the third image. The three lights are projected in a time-sharing manner with different polarization characteristics. In the present embodiment, the color wheel drive circuit 54 corresponds to a movable control unit. Further, the light source control circuit 46 performs control for causing the light source 22 to emit light in accordance with an instruction from the control unit 42.

  As described above, the light emitted from the light source 22 is controlled by the control unit 42, the light source control circuit 46, the image processing circuit 48, the light modulation element drive circuit 50, and the color wheel drive circuit 54. By the wheel 60 or the like, the first light corresponding to the first image data and the third light corresponding to the third image data are emitted as different polarization characteristics and in a time division manner. Further, the first light and the third light are projected by the illumination optical system 24 and the imaging optical system 30 so that the second image is displayed on the screen 32 so as to be visible. . The optical system 20 including the light source 22, the illumination optical system 24, the light modulation element 26, the imaging optical system 30, and the color wheel 60 has the first image and the third image as at least different polarization characteristics. In addition, the second image is displayed on the screen 32 so as to be visually recognized by time-division and overlapping projection. In this way, even if there is only one light source, it is possible to transmit not only a predetermined color but also different polarization characteristics due to displacement of the movable body, and various images such as color images can be transmitted without a plurality of light sources. Can be displayed easily.

  In the above-described embodiment, the color wheel 60 is disposed between the imaging optical system 30 and the screen 32. However, the color wheel 60 is not limited thereto. For example, the color wheel 60 is disposed between the light source 22 and the light modulation element 26. Also good. In the above-described embodiment, the circular color wheel 60 is employed. However, the present invention is not limited thereto, and for example, a rectangular color wheel may be employed.

[Third embodiment]
In the above-described embodiment, the first image and the third image are projected using one illumination optical system. However, the present invention is not limited to this. For example, a plurality of illumination optical systems are used. The first image and the third image may be projected.

  A specific embodiment will be described with reference to FIGS. 10 and 11. In addition, the description for facilitating understanding of the same configuration as the above-described embodiment is omitted.

  As shown in FIGS. 10 and 11, the first optical system includes a light source 22X (three light sources 22XR, 22XG, and 22XB), an illumination optical system 24X (lenses 24XR, 24XG, and 24XB, mirrors 24XA and 24XC), The light modulation element 26 is irradiated with illumination light based on the first image. On the other hand, the second optical system includes a light source 22Y (three light sources 22YR, 22YG, 22YB), an illumination optical system 24Y (lenses 24YR, 24YG, 24YB, mirrors 24YA, 24YC), and a polarizing plate 28Y. Thus, the light modulation element 26 is irradiated with illumination light based on the third image. The polarizing plate 28X and the polarizing plate 28Y described above have different polarization characteristics, and the polarizing plate 28X has a polarization characteristic that is different in the vertical direction from the polarization characteristic of the polarizing plate 28Y. Further, the first image light based on the first image in the first optical system and the third image light based on the third image in the second optical system have a predetermined period (for example, 1/60). Switching every second). Thus, by arranging the first optical system that displays the first image and the second optical system that displays the third image, different polarization characteristics can be realized.

  In the above-described embodiment, the first image and the third image have different polarization characteristics, and can be separated by the glasses 18 that extract image light having a predetermined polarization characteristic by time division. However, the present invention is not limited to this as long as the first image can be extracted from the first image and the third image. For example, the first image and the third image are not divided in time. May be. For example, the first image and the third image may have the same polarization characteristics. That is, it is only necessary that the first image and the third image can be configured to be displayed on the screen 32 so as to be visible by overlapping and projecting at least different polarization characteristics or time-division. .

  Specifically, even if the first image and the third image are emitted simultaneously without using time-division using an optical system independent from each other, if the polarization characteristics are different, the glasses 18 The first image can be extracted. In this case, it is preferable to provide two systems of light modulation elements.

  As shown in FIG. 12, the image projection device 10 (projection unit) and the image extraction device 19 (image extraction unit) are communicably connected by a cable 17 or the like, and a synchronization signal is transmitted between them. Or it is comprised so that reception can be performed. Therefore, the image extraction device 19 determines the display timing of the first image and the third image based on the received synchronization signal, and visually recognizes only the timing at which the first image is displayed using a liquid crystal shutter or the like. It becomes possible to make it difficult to view at the timing when the third image is displayed. Therefore, even when polarization is not performed, since the projection unit and the image extraction unit are synchronized, the first image can be visually recognized only by time division when extracted by the image extraction unit. If not extracted, the second image can be displayed so that it can be viewed, and a person who is allowed to view can be viewed, and an image that is difficult for other people to view can be displayed. Such an image projection device 10 and an image extraction device 19 include communication units that can communicate with each other.

  In the above-described embodiment, the DMD display element is employed as the light modulation element. However, the present invention is not limited thereto, and for example, a liquid crystal display element may be employed.

  In the above-described embodiment, the first image and the third image of the color image are displayed so as to overlap each other. However, the present invention is not limited to this. For example, the first image and the third image of a monochrome image are displayed. May be displayed in an overlapping manner.

  In the above-described embodiment, each pixel of the third image is a complementary color of the corresponding pixel of the first image. However, the present invention is not limited to this and may not be a complementary color.

  In the above-described embodiment, a homogeneous white image is employed as the second image that is visibly displayed on the projection surface. However, the present invention is not limited to this, and for example, a checkered pattern (check pattern) shown in FIG. As described above, the image may be a predetermined pattern or a predetermined pattern, and the third image can be easily generated.

  In the above-described embodiment, a device such as the eyeglass 18 or the image extraction device 19 that is directly viewed by the viewer is used. However, the present invention is not limited to this, and for example, imaging that captures only the first image. You may use the apparatus for indirectly visually recognizing using an apparatus.

  As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are merely examples, and various embodiments can be made based on the knowledge of those skilled in the art including the aspects described in the section of the disclosure of the invention. The present invention can be implemented in other forms that have been modified or improved.

1 is an external view showing an overview of an image projection apparatus according to an embodiment of the present invention. It is explanatory drawing which shows the optical system in the image projector of one Embodiment of this invention. It is a block diagram which shows the electric circuit comprised in the image projector of one Embodiment of this invention. It is explanatory drawing which shows the concept regarding the image displayed in the image projector of one Embodiment of this invention. It is explanatory drawing which shows the concept regarding the image displayed in the image projector of one Embodiment of this invention. It is explanatory drawing which shows the concept regarding the image displayed in the image projector of one Embodiment of this invention. It is explanatory drawing which shows the optical system in the image projector of one Embodiment of this invention. It is explanatory drawing which shows the color wheel in the image projector of one Embodiment of this invention. It is a block diagram which shows the electric circuit comprised in the image projector of one Embodiment of this invention. It is explanatory drawing which shows the concept regarding the image displayed in the image projector of one Embodiment of this invention. It is a block diagram which shows the electric circuit comprised in the image projector of one Embodiment of this invention. 1 is an external view showing an overview of an image projection apparatus according to an embodiment of the present invention. It is explanatory drawing which shows the concept regarding the image displayed in the image projector of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image projector 22 Light source 26 Light modulation element 28 Polarizing plate 48 Image processing circuit 60 Color wheel

Claims (11)

In an image projection apparatus that displays a predetermined image by projecting light onto a projection surface,
An image for generating a third image for making the image projected on the projection plane a second image different from the first image by superimposing and projecting the first image on the projection plane A generator,
A projection unit that displays the second image on the projection surface in a visually recognizable manner by projecting the first image and the third image at least with different polarization characteristics or time-division, ,
An image projection apparatus comprising: an image extraction unit that extracts the first image from the second image so as to be visible.   The image projection device according to claim 1, wherein the image extraction unit is disposed in front of a viewer's eyes.   The image projection apparatus according to claim 1, wherein the second image is a still image.   The image projection apparatus according to claim 3, wherein the second image is a homogeneous white image.   The image projection apparatus according to claim 3, wherein the second image is a predetermined pattern or an image having a predetermined pattern.   6. The image projection apparatus according to claim 1, wherein each pixel of the third image is a complementary color of a corresponding pixel of the first image.   The image projection apparatus according to claim 1, wherein the projection unit has a function of projecting the first image and the third image in a superimposed manner with different polarization characteristics.   The projection unit includes an optical system that emits a first light corresponding to the first image and a third light corresponding to the third image in a time-division manner. Item 8. The image projection device according to Item 7. The optical system is
A light source that emits light;
A light modulation element that modulates light from the light source and emits image light; and
A movable body provided with a plurality of regions for emitting light from the light source as different polarization characteristics and transmitting the light as a predetermined color;
A movable control unit that performs displacement control of the movable body,
The movable control unit performs control for displacing the movable body, whereby first light corresponding to the first image modulated by the light modulation element and third corresponding to the third image. The image projection apparatus according to claim 8, wherein the image projection apparatus has a function of projecting the light in a time division manner with different polarization characteristics. The optical system is
A light source that emits light of a predetermined color;
A light modulation element that emits the first light and the third light in a time-sharing manner by modulating light from the light source;
A polarizing plate that emits light from the light source as different polarization characteristics,
The polarizing plate overlaps the first light corresponding to the first image modulated in a time division manner by the light modulation element and the third light corresponding to the third image as different polarization characteristics. The image projection apparatus according to claim 8, wherein the image projection apparatus has a function of projecting.   The image projection apparatus according to claim 1, further comprising a communication unit that transmits or receives a synchronization signal between the projection unit and the image extraction unit.

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