| 摘要 |
A digital exposure time indicating system for a camera includes a light meter whose analog output is proportional to exposure time as a function of preset film sensitivity and aperture opening values, and the measured brightness level. The meter output is fed to a comparator, together with an analog signal from a D/A converter coupled to a counter which accumulates the pulses generated by an oscillator. When the converter output reaches the meter output the comparator signal, acting through a logic circuit, causes the counter signals to be set into a latch, whose outputs are fed through a B/D converter to an LED display. |
