System for detecting stray light

• US 5,398,055 A
• Filed: 07/16/1993
• Issued: 03/14/1995
• Est. Priority Date: 07/23/1992
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Hirose, Atsushi, Horiba, Kouji, Nonomura, Masamitsu
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US08/092,462
• Time in Patent Office: 606 Days
• Field of Search: 348/61, 348/189, 348/190, 348/191, 348/216, 348/217, 348/86, 348/125
• US Class Current: 348/61
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

An apparatus for detecting undesired stray light generated in an electronic device, comprising a high sensitive photosensing device for picking up an image of the electronic device which emits the stray light and an image pickup filter for eliminating undesired signal components contained in the sensed output by the high sensitive photosensing device.

Claims

1. A detecting apparatus for detecting stray light emitted from an electronic device comprising:

highly sensitive photosensing device for picking up a first image of said electronic device emitting the stray light and for generating a sensed output; and

filter means having an image reproducing device for receiving said sensed output and producing a second image, and an image pickup device for picking up the second image reproduced by said image reproducing device, said filter means eliminating undesired components contained in said sensed output.

2. A detecting apparatus according to claim 1, wherein said electronic device is a cathode ray tube having an electron gun emitting said stray light component.

3. A detecting apparatus according to claim 1, further comprising carrying means for carrying said cathode ray tube to a position where said photosensing device can pick up the first image of said cathode ray tube.

4. A detecting apparatus according to claim 1, wherein said high sensitive photosensing device includes an image intensifier type camera generating a video signal as said sensed output.

5. A detecting apparatus according to claim 4, wherein said image reproducing device is a monitor and said image pickup device is a camera, and said filter means further includes a video amplifier supplied with said video signal and generating an amplified video signal, which is supplied to said monitor, and a video processor supplied with the output of said camera.

6. A detecting apparatus for detecting stray light emitted from an electronic device, comprising:

a first photosensing means for picking up an image of stray light emitted from an electronic device and for generating a first electronic signal; and

filter means for eliminating undesired components contained in said electronic signal, said filter means having an image reproducing means for receiving said first electronic signal and producing a second image, and an image pickup means for receiving said second image and producing a filtered second electronic signal.

7. A detecting apparatus according to claim 6, wherein said image reproducing means comprises a monitor and said image pickup means comprises a second camera, and said filter means further comprises a video processor electrically connected to said second camera to produce said second electronic signal.

8. A detecting apparatus according to claim 6, wherein said first photosensing means comprises an image intensifier type camera and said first electronic signal comprises a video signal.

9. A detecting apparatus according to claim 8, wherein said image reproducing means comprises a monitor and said image pickup means comprises a second camera, and said filter means further comprises a video amplifier supplied with said video signal and generating an amplified video signal, said amplified video signal received by said monitor, and a video processor electrically connected to said second camera to produce said second electronic signal.