Patent FR1174684A successfully refreshed from Google Patents.
US4548495A
Expired / Lapsed
US
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Proper focusing state detecting device
Assignee: Individual
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Filing: 1982-02-23
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Granted: 1985-10-22
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Expires: 2002-02-23
Abstract
Abstract A device for automatically detecting a proper focusing state of an image-forming optical system e.g. for a photographic camera such as a single-lens reflex camera and the like, comprises a mechanism for splitting a beam of light incident through the optical system. The device does not depend intrinsically upon a current state of polarization of the incident light-beam. The mechanism for splitting a beam of light comprises a two-component lens arrangement which divides the incident beam of light into two beams of light, and a phase-shifting plate behind one of the components for lengthening the effective optical path of one of the split beams with respect to the other split beam. A first a second array of light-sensing elements is provided for receiving both of the split beams of light for evaluating and comparing the sharpness and other characteristics of the two beams of light.
Inventors
- 👤 Takeomi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:37
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/40; G02B7/00; G02B7/28; G02B7/34; G02B7/346; G02B3/00; G02B3/0006; G02B3/0037; G02B3/005
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
265 words
A focus detecting system for detecting a focus position of an image forming optical system into an object, said optical system having an image forming lens and a predetermined focal plane, said detecting system comprising: (A) dividing means for substantially dividing an effective area of said image forming lens of said optical system into two divided areas; (B) a pair of sensor arrays of light sensing elements, each of said sensor arrays being disposed to accept each of two divided light beams which have passed through each of said divided areas of said image forming lens, respectively, said sensor arrays being disposed in orthogonal relationship to the direction of a line connecting gravity centers of said divided areas of said image forming lens; (C) spatial filter means disposed between said pair of sensor arrays and said image forming lens, having transparent areas such that the direction of a line connecting gravity centers of said divided light beams, after having passed through said spatial filter means, has a selected angular relationship to a direction of extent of said sensor array; and (D) means for lengthening the optical path length of one of said divided light beams compared to that of the other divided light beams, whereby the focus position of the optical system is detected, not only by way of the detection of a relative shift of location of the optical images of said divided light beam, but also by way of the detection of a difference between the sharpness of the optical images of said divided light beams from image signals of said sensor arrays.
Claim 2
Dependent Claim
265 words
A focus detecting system for detecting a focus position of an image forming optical system into an object, said optical system having an image forming lens and a predetermined focal plane, said detecting system comprising: (A) dividing means for substantially dividing an effective area of said image forming lens of said optical system into two divided areas; (B) a pair of sensor arrays of light sensing elements, each of said sensor arrays being disposed to accept each of two divided light beams which have passed through each of said divided areas of said image forming lens, respectively, said sensor arrays being disposed in orthogonal relationship to the direction of a line connecting gravity centers of said divided areas of said image forming lens; (C) spatial filter means disposed between said pair of sensor arrays and said image forming lens, having transparent areas such that the direction of a line connecting gravity centers of said divided light beams, after having passed through said spatial filter means, has a selected angular relationship to a direction of extent of said sensor array; and (D) means for lengthening the optical path length of one of said divided light beams compared to that of the other divided light beams, whereby the focus position of the optical system is detected, not only by way of the detection of a relative shift of location of the optical images of said divided light beam, but also by way of the detection of a difference between the sharpness of the optical images of said divided light beams from image signals of said sensor arrays.
Claim 3
Dependent Claim
59 words
A focus detecting system as claimed in claim 1, further comprising: (E) means for averaging light intensity only in a direction orthogonal to the direction of extent of said sensor arrays, whereby said image signals become insensitive to a shift of location of said optical images in the direction orthogonal to the direction of extent of said sensor arrays.
Claim 4
Dependent Claim
30 words
A focus detecting system as claimed in claim 1, wherein said dividing means comprises two lens means, each having an independent optical axis corresponding to each of said sensor arrays.
Claim 5
Dependent Claim
32 words
A focus detecting system as claimed in claim 1, wherein said dividing means comprises two mirror means, each having an independent normal at its center corresponding to each of said sensor arrays.
Claim 6
Dependent Claim
32 words
A focus detecting system as claimed in claim 1, wherein said dividing means comprises two prism means, each having a surface with an independent normal corresponding to each of said sensor arrays.
Claim 7
Dependent Claim
246 words
A focus detecting system for detecting focus position of an image forming optical system onto an object, said optical system having an image forming lens and a predetermined focal plane, said detecting system comprising: (A) dividing means for substantially dividing the effective area of the image forming lens of said optical system into two divided areas; (B) a pair of sensor arrays of light sensing elements, each of said sensor arrays being disposed to accept each of two divided light beams which have passed through each of said divided areas of said image forming lens, respectively, said sensor arrays being disposed in orthogonal relationship to the direction of a line connecting gravity centers of said divided areas of said image forming lens; wherein at least one of said sensor arrays comprises plural parallel sub-arrays of light sensors; and (C) means for lengthening the optical path length of one of said divided light beams compared to that of the other divided light beam, whereby the focus position of said optical system is detected, from the image signals of said sensor arrays, not only by way of the detection of a relative shift in the direction orthogonal to the direction of said sensor arrays between the locations of the optical images of said divided light beams, but also by way of the detection of a difference between sharpnesses in the direction parallel to the direction of said sensor arrays of the optical images of said divided light beams.
Claim 8
Dependent Claim
246 words
A focus detecting system for detecting focus position of an image forming optical system onto an object, said optical system having an image forming lens and a predetermined focal plane, said detecting system comprising: (A) dividing means for substantially dividing the effective area of the image forming lens of said optical system into two divided areas; (B) a pair of sensor arrays of light sensing elements, each of said sensor arrays being disposed to accept each of two divided light beams which have passed through each of said divided areas of said image forming lens, respectively, said sensor arrays being disposed in orthogonal relationship to the direction of a line connecting gravity centers of said divided areas of said image forming lens; wherein at least one of said sensor arrays comprises plural parallel sub-arrays of light sensors; and (C) means for lengthening the optical path length of one of said divided light beams compared to that of the other divided light beam, whereby the focus position of said optical system is detected, from the image signals of said sensor arrays, not only by way of the detection of a relative shift in the direction orthogonal to the direction of said sensor arrays between the locations of the optical images of said divided light beams, but also by way of the detection of a difference between sharpnesses in the direction parallel to the direction of said sensor arrays of the optical images of said divided light beams.
Claim 9
Dependent Claim
30 words
A focus detecting system as claimed in claim 6, wherein said dividing means comprises two lens means, each having an independent optical axis corresponding to each of said sensor arrays.
Claim 10
Dependent Claim
32 words
A focus detecting system as claimed in claim 6, wherein said dividing means comprises two mirror means, each having an independent normal at its center corresponding to each of said sensor arrays.
Claim 11
Dependent Claim
31 words
A focus detecting system as claimed in claim 6, wherein said dividing means comprises two prism means, each having a surface with independent normal corresponding to each of said sensor arrays.
Claim 12
Dependent Claim
189 words
A focus detecting system for detecting focus position of an image forming optical system onto an object, said optical system having an image forming lens and a predetermined focal plane, said detecting system comprising: (A) dividing means for substantially dividing the effective area of the image forming lens of said optical system into two divided areas; (B) a pair of sensor arrays of light sensing elements, each of said sensor arrays being disposed to accept each of two divided light beams which have passed through each of said divided areas of said image forming lens, respectively, said sensor arrays being disposed in orthogonal relationship to the direction of a line connecting gravity centers of said divided areas of said image forming lens; wherein at least one of said sensor arrays comprises plural parallel sub-arrays of light sensors; and means wherein the focus position of said optical system is detected by way of the detection, from the image signals of said sensor arrays, of a relative shift in the direction orthogonal to the direction of said sensor arrays between the locations of the optical images of said divided light beams.
Claim 13
Dependent Claim
189 words
A focus detecting system for detecting focus position of an image forming optical system onto an object, said optical system having an image forming lens and a predetermined focal plane, said detecting system comprising: (A) dividing means for substantially dividing the effective area of the image forming lens of said optical system into two divided areas; (B) a pair of sensor arrays of light sensing elements, each of said sensor arrays being disposed to accept each of two divided light beams which have passed through each of said divided areas of said image forming lens, respectively, said sensor arrays being disposed in orthogonal relationship to the direction of a line connecting gravity centers of said divided areas of said image forming lens; wherein at least one of said sensor arrays comprises plural parallel sub-arrays of light sensors; and means wherein the focus position of said optical system is detected by way of the detection, from the image signals of said sensor arrays, of a relative shift in the direction orthogonal to the direction of said sensor arrays between the locations of the optical images of said divided light beams.
Claim 14
Dependent Claim
30 words
A focus detecting system as claimed in claim 10, wherein said dividing means comprises two lens means, each having an independent optical axis corresponding to each of said sensor arrays.
Claim 15
Dependent Claim
32 words
A focus detecting system as claimed in claim 10, wherein said dividing means comprises two mirror means, each having an independent normal at its center corresponding to each of said sensor arrays.
Claim 16
Dependent Claim
31 words
A focus detecting system as claimed in claim 10, wherein said dividing means comprises two prism means, each having a surface with independent normal corresponding to each of said sensor arrays.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |