Projection type video display apparatus

• US 20060028624A1
• Filed: 08/05/2005
• Published: 02/09/2006
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kaise, Naoki, Kirimura, Toru, Muraoka, Koji
• Granted Patent: US 7,325,933 B2
• Time in Patent Office: Days
• US Class Current: 353/85
• CPC Class Codes: G03B 21/26 Projecting separately subsidiary matter simultaneously with main image
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor

Abstract

A projection type video display apparatus in which a display device transmits light emitted from a light source to project a video written into the display device is characterized by comprising person detection means for detecting a person who exists within a projected video area, and control means for changing the state of the projected video when the person detection means detects the person.

Claims

1. In a projection type video display apparatus in which a display device transmits light emitted from a light source to project a video written into the display device,

the projection type video display apparatus comprising:

person detection means for detecting a person who exists within a projected video area; and

control means for changing the state of the projected video when the person detection means detects the person.

2. The projection type video display apparatus according to claim 1, further comprising

means for changing a detection range of the person detection means depending on the change in a range of the video projected from the projection type video display apparatus.

3. The projection type video display apparatus according to claim 1, wherein

the control means superimposes a black signal on a video signal when the person detection means detects the person.

4. The projection type video display apparatus according to claim 1, wherein

the control means reduces the brightness of the projected video when the person detection means detects the person.

5. The projection type video display apparatus according to claim 4, wherein

the control means lowers the illuminance of the light from the light source when the person detection means detects the person.

6. The projection type video display apparatus according to claim 4, further comprising

a diaphragm mechanism for adjusting the amount of the light from the light source,

the control means operating the diaphragm mechanism to lower the illuminance of the light from the light source when the person detection means detects the person.

7. The projection type video display apparatus according to claim 4, further comprising

a shutter mechanism, capable of being opened or closed, for shutting off the light from the light source,

the control means operating the shutter mechanism to lower the illuminance of the light from the light source when the person detection means detects the person.

8. The projection type video display apparatus according to claim 1, wherein

the control means comprises means for returning the state of the video into the original state after an elapse of a predetermined time period from the time point where the state of the video is changed.

9. The projection type video display apparatus according to claim 8, wherein

the control means comprises means for displaying, during an elapsed time period from the time point where the state of the video is changed until the state of the video is returned to the original state, the elapsed time period.

10. In a projection type video display apparatus in which a display device transmits light emitted from a light source to project a video written into the display device,

the projection type video display apparatus comprising:

a plurality of person detectors respectively corresponding to a plurality of small areas obtained by dividing a projected video area for detecting persons who are positioned in the small areas; and

control means for changing, when any of the person detectors detects the person, the state of the video within the small area corresponding to the person detector that has detected the person.

14. The projection type video display apparatus according to any one of claims 10 to 13, wherein

the control means superimposes a black signal on a video signal, to change the state of the video.

15. The projection type video display apparatus according to any one of claims 10 to 13, wherein

the control means thins the video, to change the state of the video.

11. In a projection type video display apparatus in which a display device transmits light emitted from a light source to project a video written into the display device,

the projection type video display apparatus comprising:

a plurality of person detectors for respectively detecting persons who exist in a plurality of small areas obtained by dividing a projected video area;

person detection means for judging whether or not the person is detected and judging, when the person is detected, the small area where the person exists on the basis of respective detection signals of the plurality of person detectors; and

control means for changing, when the person detection means detects the person, the state of the video within the small area where the person detection means judges that the person exists.

12. The projection type video display apparatus according to claim 11, wherein

the plurality of person detectors respectively have different detection ranges, and

respective parts of the detection ranges of the adjacent person detectors are overlapped with each other.

13. The projection type video display apparatus according to claim 12, wherein

the person detection means comprises

means for judging, when only one of the person detectors detects the person, that the person exists in the small area corresponding to a range excluding the part, which is overlapped with the detection range of the person detector adjacent to the person detector that has detected the person, of the detection range of the person detector, and

means for judging, when the two adjacent person detectors detect the person, that the person exists in the small area corresponding to the overlapped parts of the detection ranges of the two person detectors.