Automatic Exposure Sensor Circuit; Arithmetic And Control Unit - Toshiba 1550 Service Manual

(3) Automatic exposure sensor circuit (PWA-F-AES-140)
Through the action of IC1, the incidence of light upon protocell PD1 generates an AES signal on J3-
6.
Dim reflected lightf
Intense reflected lightf
(4)

Arithmetic and control unit

The arithmetic and control unit is composed of the following two blocks.
1 EEPROM built-in SRAM ................. Consists of IC9 (STK10C68), which stores exposure ad-
(NV-RAM)
2 CPU (IC10) ..................................... Incorporates software which computes the voltage to be
Mar. 1998 © TOSHIBA
Small AES output
Large AES output
justment data to ensure that optimal exposure is performed
for each reproduction ratio and for automatic exposure.
impressed on the lamp in accordance with such copying
modes as photographic magnification, automatic exposure,
and manual exposure, as well as adjustment data inside
the SRAM.
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