| 摘要 |
PURPOSE:To operate data accurately within a limited short time, by inputting the number of pulses in synchronizing with an operating pulse in series, executing double-pulse operation sequentially at a ternary counter, and approximating the fraction with compensative operation. CONSTITUTION:Input information of an aperture and the sensitivity of a photo- film is inputted to a ternary counter 2 and an end of pulse detecting circuit 3 in synchronizing with a timing signal, in the shutter time setting of a camera. Outputs at terminals 4-6 of the counter 2 go to an H level when the number of input pulses reaches 3N+1, 3N+2, 3N+3 (where N is an integral number) respectively and go to an L level at the next pulse incoming. The same output as the terminal 6 is inputted to an OR gate 4 via an FF9 from a terminal 8. The output of the terminals 4-6 of the counter 2 is inputted also to the circuit 3 and a compensating pulse generating circuit 12, where a prescribed coefficient is operated for the output of the counter 12 for the purpose of correction of approximation and generates a double operating pulse. The double operating pulse and luminous amount information are stored in registers 21, 22, the outputs are summed at a full-adder 23 for repeating the double-pulse operation. |
