| 摘要 |
PURPOSE:To improve accuracy of a focus detector of a secondary imaging deviation system by correcting electrically the photoelectrically converted output signals from two sensors. CONSTITUTION:When the accumulation of the respective elements of the sensors 10a, 10b of an image pickup device 12 by an oscillator 14, a driving circuit 13, etc. is completed, the accumulated information is transferred via CCDs 11a- 11c and is outputted time dividedly. The outputs are supplied to a multiplier circuit 19. The clocks from the oscillator 14 are up-counted by a counter 16 in synchronization therewith. The counter 16 is changed over to down-counting by a circuit 13 at neutral point between the outputs from the sensors 10, 10b. The weight coefft. from an ROM17 accessed by the counter 16 is impressed through a D/date charger 18 to a circuit 19, by which the outputs of the sensors 10a, 10b are corrected and the shading such as nonuniformity and asymmetry in the distribution of the quantity of light on the sensors 10a, 10b is dealt with. The accyracy of the focus detector of the secondary imaging deviation system is consequently improved. |
