| 摘要 |
PURPOSE:To omit an external temperature compensating resistance and to reduce a circuit scale by canceling absolute temperature proportionality by division simultaneously A/D conversion. CONSTITUTION:A generating circuit 7 for an absolute temperature proportional voltage, an operational amplifier 8, etc., correspond to a reference voltage generating means, and an operational amplifier 27, a capacitor 28, a comparator 30, a binary counter 106, etc., correspond to an A/D converting means. Then, the sum of a voltage proportional to the compressed value of an external light brightness level outputted from an operational amplifier 4 and absolute temperature and a voltage proportional to film ISO seed information outputted from an operational amplifier 19 and the absolute temperature is A/D-converted by a double integration type A/D converter and the absolute temperature proportionality is canceled at the same time. Consequently, the external temperature compensating resistance is omitted and the circuit scale is reduced.
|
