VOLTAGE APPLICATION STOPPING TIMING CONTROL DEVICE FOR ELECTRONIC DEVELOPMENT TYPE RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To properly control the stopping timings of voltage application to a recording medium so that satisfactory contrasts are obtained with respect to individual recorded pictures of a recording medium by stopping the applying voltage to the recording medium at the time the output signal level from a differentiation processing means is judged to exceed a threshold level. ;SOLUTION: The output signal of a transitivity sensor 88 is inputted to a differentiation circuit 91a to be received with a differentiation processing. The output signal of the differentiation circuit 92a is inputted to a comparator circuit 92b to be compared with a threshold level. When the output signal of the differentiation circuit 92a exceeds the threshold level, the level of the output signal of the comparator circuit 92b, that is, the level of an input signal to the reset terminal R of an RS flip-flop circuit 47 is changed over from a low level to a high level and consequently the level of an output signal from the output terminal Q of the RS flip-flop circuit 47 to a switching circuit 46b is also returned from a high level to a low level and thus the switching circuit 46b is opened to stop the voltage application from a power source circuit 46 to a recording medium RM.;COPYRIGHT: (C)1998,JPO