VIDEO SIGNAL PROCESSING UNIT

摘要

PURPOSE:To attain optimum gain control with simple constitution by applying A/D conversion to a peak data of a detected video signal, deciding an amplitude coefficient based on the peak data and applying the gain control. CONSTITUTION:An output video signal (f) being the result of amplification of an input signal (e) by an amplifier means 10 is converted into an A/D conversion means 12 and the converted signal (h) is inputted to a multiplier means 16. On the other hand, a signal (i) being the result of the A/D conversion means 13 of a signal (g) resulting from the peak detection of the signal (f) by a peak detection means 11 is compared with a prescribed value (j) by an amplifier means 14, and an amplification factor switching signal (k) is fed to the amplifier means 10 to revise the gain when the data (i) is smaller than the signal (j). The gain is not revised when the data (i) is not smaller than the signal (j). A divider means 15 divides a reference amplitude data (l) from a reference amplitude data generating means 17 by the peak data (i) to calculate an amplitude coefficient (m) to send it to a multiplier means 16. The means 16 multiplies the signal (h) by a multiple of (m) and outputs an output data (n).