| 摘要 |
PURPOSE:To provide a photometric circuit in which photometry for deciding the state of an object can be carried out at the time of firing of strobe using split photodiodes sharing a cathode or anode. CONSTITUTION:Split photodiodes 1 comprises a first photodiode PD1 having shared cathode connected with the inverted input terminal and the output terminal of a first operational amplifier circuit 2 with the anode of the first photodiode PD1 being connected with the non-inverted input terminal of the first operational amplifier circuit 2, a first integration capacitor C1, and one end of a first integration reset switch SW1 having the other end connected with a first voltage supply 4. The second photodiode PD2 has an anode connected with the non-inverted input terminal of a second operational amplifier circuit 3 in voltage follower connection, a second integration capacitor C2, and one end of a second integration reset switch SW2 having the other end connected with a second voltage supply 5. |
