| 摘要 |
PROBLEM TO BE SOLVED: To automatically adjust the level of a video signal received from a signal source to a correction level, even if the signal source generating the video signal of the JAMMA standards is changed. SOLUTION: A data latch circuit 4 latches digital data which are maximum values among video signals 100 held by a peak level hold circuit 2. A comparator 5 compares the maximum value of the video signals 100, latched at this time with a maximum value of the preceding video signals 100 having been latched by a MAX latch circuit 6. When the maximum value this time is larger than the preceding maximum value, the maximum value this time is latched by the MAX latch circuit 6. The maximum value of the video signal 100 latched by the MAX latch circuit 6 is converted into an analog signal by a D/A converter circuit 10, and the level is shifted by a level shift circuit 11 and the result is given to an attenuator 12. The attenuator 12 attenuates the level of the video signal 100 at an attenuation rate, in response to the maximum value of the video signal 100 to set the level to be a correct level. |
