초록 ▼

A focusing system for a camera using an array of photoelectric elements to sense the level of light at points in the image plane of an objective lens. The output of the elements are scanned in sequence to form a train of pulses whose amplitudes correspond to the level of light at the respective elem

A focusing system for a camera using an array of photoelectric elements to sense the level of light at points in the image plane of an objective lens. The output of the elements are scanned in sequence to form a train of pulses whose amplitudes correspond to the level of light at the respective elements as they are scanned. The pulse train is split into two pulse trains of alternate pulses. The two pulse trains are separately converted to two analog signals and applied to a differential amplifier. The difference output is clamped to a reference potential and applied to a peak detector. When the objective is in focus, the output of the peak detector is at a maximum.

대표청구항 ▼

A focusing control circuit for a camera, or the like, having an objective lens, comprising: a self-scanning photoelectric unit including an array of photoelectrical elements lying substantially in the image plane of the lens and means scanning the output of each of the elements in timed sequence to

A focusing control circuit for a camera, or the like, having an objective lens, comprising: a self-scanning photoelectric unit including an array of photoelectrical elements lying substantially in the image plane of the lens and means scanning the output of each of the elements in timed sequence to provide a series of pulses in timed sequence whose amplitudes correspond to the level of light on the respective elements, means switching successive pulses of said series alternately to two outputs, means converting the series of pulses at the two outputs to two analog signals, differential means receiving the two continuous analog signals for generating a continuous analog difference signal whose amplitude varies in proportion to the difference in amplitude of the two analog signals, and peak detector means responsive to said continuous difference signal for generating a maximum output when the lens is focused on the image plane.