| 摘要 |
PROBLEM TO BE SOLVED: To detect and announce that the viewing angle of a monitor camera is covered. SOLUTION: An AGC part 2 controls the gain, and an ESC(electronic shutter control) part 3 controls the shutter speed of an imaging part 1, according to a video signal level from the imaging part 1, and a video signal in a fixed level is inputted to a monitor 4. When an illumination determining part 5 determines that the viewing angle of the imaging part is darkened, based on the gain control signal of the AGC part and the shutter control signal of the ESC part, it is determined that an auxiliary illumination is necessary; and an auxiliary illumination 7 is lighted via an illumination control part 6. When the viewing angle of the imaging up part is covered, the beam of lights of the auxiliary illumination is reflected by the cover and is made incident on the imaging part so that the viewing angle can be brightened; and the auxiliary illumination is lighted out, and this operation is repeated. A prescribed time is counted by the time counter of a count part 8, and the repeated number of times of the lighting and light out of the auxiliary illumination is counted; and when the lighting and light out of the auxiliary illumination is repeated not less than the prescribed number of times in the prescribed time, it is determined that the viewing angle of the image pickup part is covered by a cover determining part 9, and announced by an announcing part 10.
|
