Projection type image display apparatus

• US 20050035943A1
• Filed: 09/20/2004
• Published: 02/17/2005
• Est. Priority Date: 07/09/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kojima, Akihiro
• Granted Patent: US 7,144,117 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

Disclosed herein is a projection type image display apparatus comprising projection means for projecting an image on an image-displaying screen by scanning with a laser beam, and detection means for detecting the presence or absence of an intruding object between the projection means and the screen, wherein detection by the detection means is conducted relative to a position preceding the laser beam in the scan direction of the laser beam.

Claims

1. A projection type image display apparatus comprising:

projection means for projecting an image on an image-displaying screen by scanning with a laser beam, and

detection means for detecting the presence or absence of an intruding object between said projection means and said screen, wherein

detection by the detection means is conducted relative to a position preceding said laser beam in the scan direction of said laser beam.

2. The projection type image display apparatus as set forth in claim 1, wherein said detection means radiates a detection beam invisible to the human eyes and receives and detects said reflected detection beam to thereby detect the presence or absence of said intruding object.

3. The projection type image display apparatus as set forth in claim 1, wherein said detection means is capable of measuring the distance to said intruding object by said detection beam.

4. The projection type image display apparatus as set forth in claim 1, wherein said laser beam is projected from said projection means onto said screen in the state of a laser beam modulated in one-dimensional direction, and said scanning is conducted in a direction substantially orthogonal to the longitudinal direction of said beam.

5. The projection type image display apparatus as set forth in claim 1, wherein in said projection means, said scanning with said laser beam is conducted by a mirror surface turned around an axis, and said detection beam is radiated onto said mirror surface at an angle different from the incidence angle of said laser beam onto said mirror surface.

6. The projection type image display apparatus as set forth in claim 1, wherein said detection means has a part of an image display region of said screen as a detection region.

7. The projection type image display apparatus as set forth in claim 1, wherein said detection means has a region in the exterior of an image display region of said screen as a detection region.

8. The projection type image display apparatus as set forth in claim 2, wherein the irradiation with said detection beam is conducted by said projection means.

9. The projection type image display apparatus as set forth in claim 2, wherein said detection means comprises a beam detecting portion for receiving and detecting said detection beam, and said beam detecting portion is comprised of a one-dimensional image pickup device.