Projection display device

• US 7,210,786 B2
• Filed: 09/15/2004
• Issued: 05/01/2007
• Est. Priority Date: 09/26/2003
• Status: Active Grant

• Current Assignee: Sharp NEC Display Solutions, Ltd.
• Original Assignee: NEC Viewtechnology, Ltd.
• Inventors: Tamura, Youichi, Nirasawa, Takashi
• Primary Examiner(s): Koval; Melissa Jan
• Application Number:
  US10/940,611
• Publication Number:
  US 20050068500A1
• Time in Patent Office: 958 Days
• Field of Search: 353/28, 353/30, 353/69, 353/85, 353/97, 353/122, 348/744, 348/745, 712/224
• US Class Current: 353/28
• CPC Class Codes: H04N 5/57 Control of contrast or brightness
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

The projection display device stores, in a frame memory, a shot image of a test pattern for cases where the obstacle is not represented in the region of the projection; compares, at a comparison unit, a shot image of the test pattern for the case where the obstacle is represented in the region of the projection, with the stored shot image of the test pattern in order to detect an obstacle present in the region of the projection; generates, at an image-mask enlargement-processing unit, an image mask section having a region larger than the region of the detected obstacle; and effects, at a luminance control unit, a control to reduce the luminance in the image mask section.

Claims

1. A projection display device comprising:

an image processing means for processing input image data to generate a display image;

a projection lens for projecting the display image processed by said image processing means onto a screen to make an enlarged presentation of a video picture;

a test-pattern projection means for projecting a test pattern on said screen through said projection lens;

an imaging means provided with an imaging element for shooting the projected video picture and a photograph lens;

a shot-image analysis means for analyzing a shot image generated by said imaging means and also for detecting an obstacle within a region of said projected video picture;

an image mask generation means for generating an image mask that corresponds to the detected obstacle; and

a luminance control means for controlling luminance corresponding to said image mask;

wherein said image mask generation means is provided with an image-mask enlargement-processing means for generating an image mask section that has a larger region than the region corresponding to the detected obstacle.

2. A projection display device according to claim 1, wherein said shot-image analysis means comprising:

a memory means for storing a shot image of said test pattern for a case where said obstacle is not represented in the region of the projected video picture;

a means for comparing the shot image of said test pattern, for cases where said obstacle is pictured in the region of the projected video picture, with the shot image of said test pattern that is stored in said memory means;

an obstacle detection means for detecting said obstacle based on a comparison result; and

a switching means for transferring a received shot image of a test pattern to said memory means through a switching operation, said received shot image being a shot image of said test pattern, for cases where said obstacle does not exist in the region of the projected video picture, and being received from said imaging means.

3. A projection display device according to claim 1, wherein said luminance control means has a means for reducing luminance.

4. A projection display device according to claim 1, wherein said image-mask enlargement-processing means has a means for determining said image mask section based on at least one specification including a size of the screen, a movement speed of the obstacle, a horizontal resolution, and a time required after the detection of said obstacle until the control of luminance is implemented by said luminance control means.

5. A projection display device according to claim 1, wherein said image-mask enlargement-processing means has a means for enlarging said image mask section in a vertical and/or horizontal direction.

6. A projection display device according to claim 1, wherein said test pattern includes a pattern in a horizontal straight line.

7. A projection display device according to claim 1, wherein said test pattern includes a straight line positioned in a direction that is not parallel to the straight line connecting said projection lens with said imaging means.

8. A projection display device according to claim 1, wherein said test pattern is pictured through an infrared ray.

9. A projection display device according to claim 6, wherein said test pattern is pictured through an infrared ray.

10. A projection display device according to claim 7, wherein said test pattern is pictured through an infrared ray.

11. A projection display device according to claim 2, wherein said obstacle detection means has a means for detecting a linearity of said test pattern which appears in a shot image and further for detecting a non-linear portion as said obstacle.

12. A projection display device according to claim 2, wherein said obstacle detection means has a means for seeking a difference between the shot image of said test pattern stored in said memory means and the shot image of said test pattern for cases where said obstacle is pictured in the region of a projected video picture, and

a means for binarizing the sought difference.

13. The projection display device according to claim 1, wherein said test pattern projection means projects a test pattern using visible light.