JPH05236339

• Main Authors: KITANO OSAMU, NAKAMURA YOSHIO
• Format: Patent
• Language: English
• Published: 10.09.1993
• Edition: 5
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE:To easily detect even a black or white dot out of a range equivalent to the reduced part of a video signal by multiplying the video signal by the ratio between an input video signal and a prescribed input level for each synchronizing signal of a processor. CONSTITUTION:An A/D converter 13 converts the video signal (a) inputted via an input amplifier 11 or the output signal (e) of a multiplier 12 into a digital signal and outputs this signal to a processor 17 with the action of a contact of a relay 18. Meanwhile, a D/A converter 14 converts the ratio data inputted from the processor 17 into the analog data and outputs this data to a multiplier 12 as a ratio correction signal (d). Then, the multiplier 12 multiplies both signals (a) and (d) as the 1st and 2nd input signals with the input of a scan signal for each synchronizing signal of the processor 17 and then outputs this multiplication result to an output amplifier 20.