US3846629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensitivity balancing apparatus for photo responsive detecting circuits
Assignee: Honeywell Inc
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Filing: 1973-12-06
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Granted: 1974-11-05
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Expires: 1993-12-06
Abstract
Abstract A focus detecting system includes first and second lens devices for forming first and second auxiliary images of an object on first and second detector devices, respectively. Each detector device includes a corresponding plurality of linearly displaced light responsive elements. Before initiating a focus detecting function, a light diffusing device is positioned in the light paths ahead of the detector devices to effect substantially equal illumination of the detector devices. A balancing circuit connected to the detector devices or the a balancing charge representative of any inequality in the signals fuel to the corresponding light responsive elements. When the focus detecting action is initiated, the light diffusing device is removed and one of the lens devices moves with respect to its associated detector device to shift the light distribution pattern of the corresponding auxiliary image. The moving lens device is so coupled to a moving objective lens, which focusses a principal image of the object on a light sensitive film, that when the principal image is in focus, equal amounts of light will fall on corresponding light responsive elements of the first and second detector devices. The stored balancing charge is combined with the signals provided by the photo responsive elements during a focus detecting operation to provide compensated signals which are then processed to effect the termination of the movement of the objective lens when the principal image is properly focussed.
Inventors
- 👤 N Stauffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:57
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
217 words
An apparatus comprising: means arranged to receive radiation from an object for defining a light path including first and second discretely identifiable portions of said radiation; first and second detecting devices positioned in said light path and arranged for sensing the intensity of said first and second discretely identifiable portions of said radiation to produce a difference signal at a common terminal representative of the difference therebetween; circuit means connected to said common terminal; means selectively operable between a first position in said light path, and a second position out of said light path, said selectively operable means, when in said first position, being effective to cause substantially equal amounts of radiation to fall on said first and second detecting devices, said circuit means including means for storing a balancing signal representative of the difference signal appearing at said common terminal when said selectively operable means is in said first position, said circuit means further including means for combining said stored balancing signal with said difference signal generated when said selectively operable means is in said second position to provide a compensated difference signal which is representative of the difference between said balancing signal and said difference signal, said compensated difference signal being compensated for any inequality in effective sensitivity between said first and second detecting devices.
Claim 2
Independent Claim
217 words
An apparatus comprising: means arranged to receive radiation from an object for defining a light path including first and second discretely identifiable portions of said radiation; first and second detecting devices positioned in said light path and arranged for sensing the intensity of said first and second discretely identifiable portions of said radiation to produce a difference signal at a common terminal representative of the difference therebetween; circuit means connected to said common terminal; means selectively operable between a first position in said light path, and a second position out of said light path, said selectively operable means, when in said first position, being effective to cause substantially equal amounts of radiation to fall on said first and second detecting devices, said circuit means including means for storing a balancing signal representative of the difference signal appearing at said common terminal when said selectively operable means is in said first position, said circuit means further including means for combining said stored balancing signal with said difference signal generated when said selectively operable means is in said second position to provide a compensated difference signal which is representative of the difference between said balancing signal and said difference signal, said compensated difference signal being compensated for any inequality in effective sensitivity between said first and second detecting devices.
Claim 3
Dependent Claim
91 words
The apparatus as set forth in claim 1 wherein said circuit means includes: an amplifier means having first and second input terminals and an output terminal; a capacitor means connected between said common terminal and said first input terminal of said amplifier means; and an impedance means connected between said first input terminal of said amplifier means and a common reference potential, said second input terminal of said amplifier means also being connected to said common reference potential, said amplifier means providing said compensated difference signal at said output terminal thereof.
Claim 4
Dependent Claim
17 words
The apparatus as set forth in claim 1 wherein said first and second detecting devices are photoresistors.
Claim 5
Dependent Claim
115 words
The apparatus as set forth in claim 1 wherein said first and second detecting devices each comprise a like plurality of photoresistors having first and second terminals, said first terminals of said photoresistors of said first detecting device being commonly connected to means for connection to a first voltage source, said first terminals of said photoresistors of said second detecting device being commonly connected to means for connection to a second voltage source, said second terminals of corresponding elements of said first and second detecting devices being connected together thereby forming a plurality of said common terminAls, said apparatus including one of said circuit means connected to each of said plurality of said common terminals.
Claim 6
Dependent Claim
47 words
The apparatus as set forth in claim 4 wherein said apparatus includes a signal processing means which comprises: means for rectifying said compensated difference signals; and means connected to said rectifying means for providing a composite signal representative of the sum of said rectified, compensated difference signals.
Claim 7
Dependent Claim
18 words
The apparatus as set forth in claim 1 wherein said first and second detecting devices are photovoltaic elements.
Claim 8
Dependent Claim
122 words
The apparatus as set forth in claim 1 wherein said first and second detecting devices each comprise a like plurality of photovoltaic elements having first and second terminals, said first terminals of said photovoltaic elements being connected to a common reference potential; a plurality of differential amplifier circuits each having first and second input terminals and an output terminal, said second terminals of corresponding photovoltaic elements of said first and second detecting devices being connected elements said first and second input terminals, respectively, of different ones of said differential amplifier circuits, said output terminals of said differential amplifier circuits each being connected to a separate common terminal, said apparatus including one of said circuit means connected to each of said common terminals.
Claim 9
Dependent Claim
46 words
The apparatus as set forth in claim 7 wherein said apparatus includes a signal processing means comprising: means for rectifying said compensated difference signals; and means connected to said rectifying means for providing a composite signal representative of the sum of said rectified compensated difference signals.
Claim 10
Dependent Claim
50 words
The apparatus as set forth in claim 1 wherein said defining means further includes first and second lens means for receiving spatially separated segments of radiation from the object, said first lens means defining said first discretely identifiable portion and said second lens means defining said second discretely identifiable portion.
Claim 11
Dependent Claim
386 words
A focus detecting apparatus for use with means for focussing a principal image of an object on a predetermined plane, the focus detecting apparatus comprising: first and second means arranged to receive radiation from the object for defining a light path including first and second discretely identifiable portions of said radiation, said first and second portions being effective to form first and second auxiliary images of the object, respectively, said second auxiliary images being spatially separated from said first auxiliary image; first and second detecting devices positioned to receive radiation from said first and second auxiliary images, respectively; means operable conjointly with said means for focussing the principal image for introducing relative motion between at least one of said auxiliary images and the associated detecting device; said first and second detecting devices each including a similar array of a plurality of light responsive elements, each element being arranged to provide an electrical signal representative of the intensity of the light impinging thereon; means for comparing the electrical signal from each element of one of said arrays with the electrical signal from a corresponding element of the other of said arrays, and deriving from each such comparison a difference signal which appears at a separate common terminal; signal processing means; circuit means for receiving said difference signals, said circuit means being connected to said signal processing means; means selectively operable between a first position in said light path and a second position out of said light path, said selectively operable means, when in said first position, being effective to cause substantially equal amounts of radiation to fall on said first and second detecting devices, said circuit means including means for storing balancing signals representative of eAch of the difference signals appearing when said selectively operable means is in said first position, said circuit means further including means for combining said balancing signals with the associated difference signals generated when said selectively operable means is in said second position, thereby providing for each such combination, a compensated difference signal which is compensated for any inequality in effective sensitivity between said first and second detecting devices, said signal processing means being operable to process the compensated difference signals to produce an output signal which is representative of the condition of focus of the principal image on the predetermined plane.
Claim 12
Dependent Claim
386 words
A focus detecting apparatus for use with means for focussing a principal image of an object on a predetermined plane, the focus detecting apparatus comprising: first and second means arranged to receive radiation from the object for defining a light path including first and second discretely identifiable portions of said radiation, said first and second portions being effective to form first and second auxiliary images of the object, respectively, said second auxiliary images being spatially separated from said first auxiliary image; first and second detecting devices positioned to receive radiation from said first and second auxiliary images, respectively; means operable conjointly with said means for focussing the principal image for introducing relative motion between at least one of said auxiliary images and the associated detecting device; said first and second detecting devices each including a similar array of a plurality of light responsive elements, each element being arranged to provide an electrical signal representative of the intensity of the light impinging thereon; means for comparing the electrical signal from each element of one of said arrays with the electrical signal from a corresponding element of the other of said arrays, and deriving from each such comparison a difference signal which appears at a separate common terminal; signal processing means; circuit means for receiving said difference signals, said circuit means being connected to said signal processing means; means selectively operable between a first position in said light path and a second position out of said light path, said selectively operable means, when in said first position, being effective to cause substantially equal amounts of radiation to fall on said first and second detecting devices, said circuit means including means for storing balancing signals representative of eAch of the difference signals appearing when said selectively operable means is in said first position, said circuit means further including means for combining said balancing signals with the associated difference signals generated when said selectively operable means is in said second position, thereby providing for each such combination, a compensated difference signal which is compensated for any inequality in effective sensitivity between said first and second detecting devices, said signal processing means being operable to process the compensated difference signals to produce an output signal which is representative of the condition of focus of the principal image on the predetermined plane.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |