| 摘要 |
PURPOSE: To decrease logarithmic conversion circuits required to individual circuits by furnishing a selecting means (switch) to select either of the outputs of a light measuring circuit and a temp. sensing circuit. CONSTITUTION: In a light measuring circuit, the brightness of an object to be photographed is outputted to a contact between a light measuring element 2a and a voltage dividing resistance 2b. The outputted voltage is taken into an A/D converter 7 through a switch 7a so that conversion into digital value is made, and the result is outputted to a CPU 1. The CPU 1 makes reference to a brightness conversion table accommodated a ROM 1a and determines the brightness of the object to be photographed. A temp. sensing circuit gives the ambient temp. to the contact between a thermistor 6a and another voltage dividing resistance 6b. The outputted voltage is taken in the converter 7 through the switch 7a so that conversion into digital value is made, and the result is outputted to the CPU 1. The CPU 1 makes reference to a temp. conversion table accommodated in the ROM 1a and determines the ambient temp. This determination of temp. is made for compensating the thermal characteristics of component. |
