Abstract A focalization detecting device in a camera utilizing a self-scanning type photoelectric device having a number of elements disposed at a position equivalent to the position of the image forming plane of a lens. A drive circuit drives the photoelectric element and a delay circuit delays a discrete output waveform of the photoelectric element the time corresponding to the scanning period of one or two elements. A difference circuit detects an output difference between the delayed waveform and the undelayed waveform. An absolute value circuit detects the absolute value of a difference output from the difference circuit and a peak value holding circuit holds a peak value in an absolute value waveform provided by the absolute value circuit in one scanning period of the photoelectric element, in such a manner that an output difference between said element is detected with a discrete photoelectric transducing output as it is. The maximum peak value output is provided when focus is obtained.
Inventors
👤 Harumi Aoki
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-01 17:42
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
A focus detecting device in a camera comprising: a single self-scanning type photoelectric device having a number of elements disposed at a position equivalent to the position of the image forming plane of a lens; a drive circuit for driving said photoelectric element to produce a single discrete time series output waveform; a delay circuit for delaying said single discrete time series output waveform of said single photoelectric element by the time corresponding to at least the scanning period for one element to produce a delayed waveform; signal processing circuit means determining variations of said delayed waveform and said discrete time series output waveform in one scanning period of said photoelectric device, wherein an output difference between said elements is detected as an unfiltered discrete photoelectric transducing output, and a maximum output is provided when proper focalization is obtained.
Claim 2
Dependent Claim
139 words
A focus detecting device in a camera comprising: a single self-scanning type photoelectric device having a number of elements disposed at a position equivalent to the position of the image forming plane of a lens; a drive circuit for driving said photoelectric element to produce a single discrete time series output waveform; a delay circuit for delaying said single discrete time series output waveform of said single photoelectric element by the time corresponding to at least the scanning period for one element to produce a delayed waveform; signal processing circuit means determining variations of said delayed waveform and said discrete time series output waveform in one scanning period of said photoelectric device, wherein an output difference between said elements is detected as an unfiltered discrete photoelectric transducing output, and a maximum output is provided when proper focalization is obtained.
Claim 3
Dependent Claim
35 words
A focus detecting device as in claim 1 wherein said signal processing means comprises a difference circuit for detecting a difference between said delayed and discrete output waveforms and for producing a difference signal output.
Claim 4
Dependent Claim
46 words
A focus detecting device as in claim 2, wherein said signal processing means further comprises an absolute value circuit for detecting the absolute value of said difference signal output and a peak value holding circuit for holding a peak value detected by said absolute value circuit.
Claim 5
Dependent Claim
37 words
A focus detecting device as in claims 1, 2, or 3 wherein said delay circuit delays a discrete output waveform for a time corresponding to the scanning period for two elements of said self scanning photoelectric device.
Claim 6
Dependent Claim
25 words
A focus detecting device as in claims 1, 2 or 3 further comprising amplifier means interposed between said self-scanning photoelectric device and said delay circuit.
Claim 7
Dependent Claim
39 words
A focus detecting device as in claim 3, wherein said peak value holding circuit holds a single peak value detected by said absolute value circuit, the output of said focus detecting device being responsive to said single peak value.