Simplified automatic SLR camera - has digital storage of exposure reading and digital/analogue convertors

摘要

Conventional SLR cameras with automatic exposure control store the exposure reading in a digital form as a series of impulses. This requires a decoding counter and an exclusive OR gate to process the stored information. A much simpler system is obtained if the exposure reading is passed through a digital analogue converter for storage, with the analogue signal being compared with the preset exposure factors. When used for exposure the signal is converted back into an analogue signal for a simple comparison with the preset values and with a subsequent simpler exposure control. The control is independent of variations in temperature.