This nonprovisional application is based on Japanese Patent Application No. 2011-040102 filed on Feb. 25, 2011 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a projection-type image display apparatus, and particularly to a projection-type image display apparatus that includes an image capture unit capturing an image projected on a projection plane.
2. Description of the Related Art
In recent years, projection-type image display apparatuses have become mounted with a camera that captures an image projected on a projection plane to have an interactive capability of focusing an image to be projected on the projection plane based on the image captured by the camera, or producing, in the form of a superimposed image, a track of a pointing device whose image is captured by the camera. Thus, the projection-type image display apparatus involves a problem that the interactive capability does not properly function if ambient light is cast on the projection plane. Specifically, due to the influence of the ambient light, focusing fails or the track of the pointing device cannot be produced in the form of a superimposed image.
The conventional projection-type image display apparatus uses a pointing device having a light source that flashes on and off in predetermined cycles so as to distinguish the light from the light source and ambient light from each other and determine whether or not ambient light is cast on the projection plane. Thus, regarding the conventional projection-type image display apparatus, the position of the projection-type image display apparatus or the position of the projection plane is adjusted so that the ambient light distinguished by means of the pointing device is not cast on the projection plane.
The conventional projection-type image display apparatus, however, cannot determine whether or not ambient light is cast on the projection plane if the apparatus is not provided with the pointing device. Further, for the conventional projection-type image display apparatus, it is necessary to perform the operation of adjusting the position of the projection-type image display apparatus or projection plane so that ambient light is not cast on the projection plane, and thereafter using again the pointing device to determine whether or not there is ambient light cast on the projection plane. Namely the operation is complicated.
Further, regarding the conventional projection-type image display apparatus, if the position of the projection-type image display apparatus or projection plane cannot be adjusted for preventing ambient light from being cast on the projection plane, the influence of the ambient light cast on the projection plane on the interactive capability cannot be alleviated.
According to an aspect of the present invention, a projection-type image display apparatus projects an image on a projection plane, and includes a projection unit, an image capture unit, an ambient light detection unit, and a superimposed image generation unit. The projection unit projects an image on the projection plane through a lens. The image capture unit captures the image projected on the projection plane by the projection unit. The ambient light detection unit detects ambient light cast on the projection plane, from the image captured by the image capture unit. The superimposed image generation unit generates information about detection of ambient light detected by the ambient light detection unit, in the form of a superimposed image to be superimposed on the image projected on the projection plane.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
In the following, embodiments of the present invention will be described in detail with reference to the drawings.
Projection unit 1 projects an image through a lens (not shown) on screen 20. Projection unit 1 is mainly constituted of an image generation unit and a light source. As the image generation unit, for example, an LCD (Liquid Crystal Display), a DMD (Digital Micromirror Device) or the like is used. As the light source, for example, a halogen lamp, a laser light source or the like is used.
Camera 2 is an image capture unit capturing an image projected on screen 20 by projection unit 1. Camera 2 is constituted of a lens, a CCD (Charge Coupled Device), and a photodetector such as CMOS sensor. Here, camera 2 may be an image capture unit configured in any manner as long as the image capture unit is configured to be capable of capturing an image projected on screen 20 by projection unit 1.
Screen detection unit 3 detects the position of screen 20 on which an image is projected by projection unit 1. Screen detection unit 3 detects the position of screen 20 by, for example, performing predetermined processing on an entirely white image projected on screen 20 by projection unit 1 and captured by camera 2. Here, projection-type image display apparatus 10 may not be provided with screen detection unit 3 in the case where projection unit 1 can project an image on screen 20 without detection of the position of screen 20.
Ambient light detection unit 4 detects ambient light which is cast on screen 20, from an image captured by camera 2. Specifically, ambient light detection unit 4 divides the image captured by camera 2 into a plurality of sub-regions, and compares an average brightness of each of the sub-regions with an average brightness of the whole region, to detect ambient light cast on screen 20.
Image processing unit 5 performs predetermined processing on an image projected on screen 20 by projection unit 1 or an image captured by camera 2, in order to allow the interactive capability to properly function. In particular, image processing unit 5 performs predetermined processing in the case where the position of projection-type image display apparatus 10 or screen 20 is not adjusted, or ambient light is still cast on screen 20 in spite of the fact that the position of projection-type image display apparatus 10 or screen 20 has been adjusted.
OSD (On Screen Display) generation unit 6 is a superimposed image generation unit generating, in the form of a superimposed image to be superimposed on an image projected on screen 20, information about detection of ambient light detected by ambient light detection unit 4. OSD generation unit 6 generates information about detection “ambient light has been detected” for example, in the form of a superimposed image to be superimposed on an image projected on screen 20, in order to allow a user to recognize the fact that ambient light is cast on screen 20.
A description will now be given of an operation of detecting ambient light by projection-type image display apparatus 10 according to the first embodiment of the present invention.
Next, ambient light detection unit 4 detects, from an image captured by camera 2, whether or not there is ambient light cast on screen 20 to determine whether or not ambient light is cast on screen 20 (step S202). When ambient light detection unit 4 determines that ambient light is cast on screen 20 (YES in step S202), ambient light detection unit 4 further determines whether or not it is the first time that ambient light detection unit 4 has detected the ambient light cast on screen 20 (step S203).
In the case where ambient light detection unit 4 has detected ambient light cast on screen 20 for the first time (YES in step S203), OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S204).
In the case where the number of times ambient light detection unit 4 has detected ambient light cast on screen 20 is two or more times (NO in step S203), OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S205).
The superimposed image which is displayed by being superimposed on an image projected on screen 20 is not limited to the superimposed image shown in
Further, the superimposed image may not be the image indicating the position of ambient light cast on screen 20 shown in
Projection-type image display apparatus 10 determines whether or not information has been input that gives an instruction to adjust the position of projection-type image display apparatus 10 or screen 20 for preventing ambient light from being cast on screen 20 (step S207). When projection-type image display apparatus 10 determines that the information has been input that gives an instruction to adjust the position of projection-type image display apparatus 10 or screen 20 for preventing ambient light from being cast on screen 20 (YES in step S207), it returns the process to step S202.
When projection-type image display apparatus 10 determines that the information has not been input that gives an instruction to adjust the position of projection-type image display apparatus 10 or screen 20 for preventing ambient light from being cast on screen 20 (NO in step S207), image processing unit 5 performs predetermined processing on an image to be projected on screen 20 by projection unit 1 or on an image captured by camera 2, so that the interactive capability properly functions (step S208). Specifically, image processing unit 5 converts a predetermined pattern image projected on screen 20 into a predetermined pattern image that avoids the position of ambient light cast on screen 20, based on the information about detection of the ambient light detected by ambient light detection unit 4.
Further, image processing unit 5 may remove, from a predetermined pattern image captured by camera 2, an image located at the position of ambient light cast on screen 20, based on the information about detection of the ambient light detected by ambient light detection unit 4.
Alternatively, image processing unit 5 may complement an image located at the position of ambient light cast on screen 20, based on the information about detection of ambient light detected by ambient light detection unit 4 from the image captured by camera 2.
In the case as shown in
Referring back to
Next, projection-type image display apparatus 10 displays the superimposed image shown in
As heretofore described, projection-type image display apparatus 10 according to the first embodiment of the present invention generates, by OSD generation unit 6, information about detection of ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20. Thus, a user can easily know whether or not ambient light is cast on screen 20. The user can therefore easily adjust, based on the superimposed image, the position of projection-type image display apparatus 10 or screen 20 so that no ambient light is cast on screen 20. Here, the operation of detecting ambient light by projection-type image display apparatus 10 shown in
A projection-type image display apparatus according to a second embodiment of the present invention is configured identically to projection-type image display apparatus 10 shown in
Next, ambient light detection unit 4 detects, from an image captured by camera 2, whether or not there is ambient light cast on screen 20 to determine whether or not ambient light is cast on screen 20 (step S302). When ambient light detection unit 4 determines that ambient light is cast on screen 20 (YES in step S302), ambient light detection unit 4 further determines whether or not it is the first time that ambient light detection unit 4 has detected the ambient light cast on screen 20 (step S303).
In the case where it is the first time that ambient light detection unit 4 has detected ambient light cast on screen 20 (YES in step S303), OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S304). In step S304, projection-type image display apparatus 10 displays the superimposed image shown in
In the case where the number of times ambient light detection unit 4 has detected ambient light cast on screen 20 is two or more times (NO in step S303), ambient light detection unit 4 determines whether or not there is a change in position of the ambient light detected this time, relative to the position of the ambient light detected last time (step S305). When ambient light detection unit 4 determines that there is a change in position of the ambient light detected this time relative to the position of the ambient light detected last time (YES in step S305), OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S306). In step S306, projection-type image display apparatus 10 displays the superimposed image shown in
When ambient light detection unit 4 determines that the position of ambient light detected this time remains unchanged relative to the position of the ambient light detected last time (NO in step S305), in spite of the fact that the position of projection-type image display apparatus 10 or screen 20 has been adjusted so that ambient light is not cast on screen 20, it determines that what is detected as ambient light this time is caused by disturbance of reflection of light by dirt sticking to screen 20 or by magnet or the like attached to screen 20. Then, OSD generation unit 6 generates information about detection of ambient light detected by ambient light detection unit 4, in the form of a superimposed image superimposed on an image displayed on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S307).
Projection-type image display apparatus 10 determines whether or not information has been input that gives an instruction to adjust the position of projection-type image display apparatus 10 or screen 20 for preventing ambient light from being cast on screen 20 (step S308). When projection-type image display apparatus 10 determines that the information has been input that gives an instruction to adjust the position of projection-type image display apparatus 10 or screen 20 for preventing ambient light from being cast on screen 20 (YES in step S308), it returns the process to step S302.
When projection-type image display apparatus 10 determines that the information has not been input that gives an instruction to adjust the position of projection-type image display apparatus 10 or screen 20 for preventing ambient light from being cast on screen 20 (NO in step S308), image processing unit 5 performs predetermined processing on an image to be projected on screen 20 by projection unit 1 or on an image captured by camera 2, so that the interactive capability properly functions (step S309).
When ambient light detection unit 4 determines that no ambient light is cast on screen 20 (NO in step S302), OSD generation unit 6 generates information about detection of ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S310). In S310, projection-type image display apparatus 10 displays the superimposed image shown in
Then, projection-type image display apparatus 10 displays the superimposed image shown in
As heretofore described, projection-type image display apparatus 10 according to the second embodiment of the present invention determines, by ambient light detection unit 4, whether or not the position of the ambient light detected this time is different from the position of the ambient light detected last time. Thus, it can be determined that dirt sticking to screen 20, or magnet or the like attached to screen 20 disturbs reflection of light and this is detected as ambient light.
A description will be given of an operation of detecting ambient light by projection-type image display apparatus 11 according to the third embodiment of the present invention.
Next, ambient light detection unit 4 detects, from an image captured by camera 7, whether or not there is ambient light cast on screen 20 to determine whether or not ambient light is cast on screen 20 (step S402). When ambient light detection unit 4 determines that ambient light is cast on screen 20 (YES in step S402), ambient light detection unit 4 further determines whether or not it is the first time that ambient light detection unit 4 has detected ambient light cast on screen 20 (step S403).
In the case where it is the first time that ambient light detection unit 4 has detected ambient light cast on screen 20 (YES in step S403), OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S404). In step S404, projection-type image display apparatus 11 displays the superimposed image shown in
In the case where the number of times ambient light detection unit 4 has detected ambient light cast on screen 20 is two or more times (NO in step S403), it is determined whether or not camera 7 is attached to the outside of projection-type image display apparatus 11 (step S405). An information flag may change in response to attachment of camera 7 to the outside of projection-type image display apparatus 11, for example. Ambient light detection unit 4 may detect this change and determine that camera 7 is attached to the outside of projection-type image display apparatus 11.
When ambient light detection unit 4 determines that camera 7 is not attached to the outside of projection-type image display apparatus 11 (NO in step S405), OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S406). It is supposed here that projection-type image display apparatus 11 contains camera 2 (not shown). In step 5406, projection-type image display apparatus 11 displays the superimposed image shown in
When ambient light detection unit 4 determines that camera 7 is attached to the outside of projection-type image display apparatus 11 (YES in step S405), it determines that the position of camera 7 attached to the outside of projection-type image display apparatus 11 causes ambient light to be cast on screen 20 in spite of the fact that the position of projection-type image display apparatus 11 or screen 20 has been adjusted. Then, OSD generation unit 6 generates information about detection of the ambient light detected by ambient light detection unit 4, in the form of a superimposed image superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S407).
Projection-type image display apparatus 11 determines whether or not information has been input that gives an instruction to adjust the position of projection-type image display apparatus 11 or screen 20 for preventing ambient light from being cast on screen 20 (step S408). When projection-type image display apparatus 11 determines that the information has been input that gives an instruction to adjust the position of projection-type image display apparatus 11 or screen 20 for preventing ambient light from being cast on screen 20 (YES in step S408), it returns the process to step S402.
When projection-type image display apparatus 11 determines that the information has not been input that gives an instruction to adjust the position of projection-type image display apparatus 11 or screen 20 for preventing ambient light from being cast on screen 20 (NO in step S408), image processing unit 5 performs predetermined processing on an image to be projected on screen 20 by projection unit 1 or on an image captured by camera 7, so that the interactive capability properly functions (step S409).
When ambient light detection unit 4 determines that no ambient light is cast on screen 20 (NO in step S402), OSD generation unit 6 generates information about detection of ambient light detected by ambient light detection unit 4, in the form of a superimposed image to be superimposed on an image projected on screen 20, and projection unit 1 projects and displays the superimposed image on screen 20 (step S410). In step S410, projection-type image display apparatus 11 displays the superimposed image shown in
Next, projection-type image display apparatus 11 displays the superimposed image shown in
As heretofore described, projection-type image display apparatus 11 according to the third embodiment of the present invention determines, by ambient light detection unit 4, whether or not camera 7 is attached to the outside of projection-type image display apparatus 11. Thus, it can be determined that the reason why ambient light is cast on screen 20 in spite of the fact that the position of projection-type image display apparatus 11 or screen 20 has been adjusted, is the position of camera 7 attached to the outside of projection-type image display apparatus 11.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being interpreted by the terms of the appended claims.
Number | Date | Country | Kind |
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2011-040102 | Feb 2011 | JP | national |