| 摘要 |
PURPOSE:To enable a pick-up tube to be used in compliance with any television camera even though the clamping pulse timing for setting a dark level is located on any side of horizontal or vertical scanning, by so disposing that a distance between two opposing optical blacks is symmetrical about an axis and set within a scanning distance corresponding to the time of the scanning period except a beam blanking time. CONSTITUTION:Assuming that respective dividing sizes of both optical black parts 10 and 11 with respect to the center line of a face plate 2 are L1 and L2, L1=L2 is applicable, namely L1=l2=horizontal scanning length/2 is known subject to l1+(a)=l2+(a). Then (a) is a margin and usually about 0.05-0.1mm. is practically sufficient. According to said constitution of the optical black part 11 an essential purpose of a clamping pulse is not harmed and can be used adjusted, even if timing of the clamping pulse for setting a dark level of a television camera is in either of the horizontal and vertical directions. |
