US4841326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting the focus adjusted state of an objective optical system
Assignee: Canon Inc
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Filing: 1987-11-02
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Granted: 1989-06-20
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Expires: 2007-11-02
Abstract
Abstract A focus detecting apparatus is provided with a plurality of pattern forming lenses for forming light patterns whose relative positional relation varies in conformity with the focus adjusted state of an objective optical system from lights passed through different areas on the pupil of the objective optical a sensing device is included for sensing the light patterns and producing a signal regarding the relative positional relation between the light patterns. A light divider is inclined along an optical path passing through the areas on the pupil and has a light-transmitting area through which light is refracted and transmitted. The light divider is disposed between the objective optical system and the pattern forming lenses. The pattern forming lenses are different in shape and are formed asymmetrically with respect to the optic axis of the objective optical system to correct the destruction of the light patterns caused by the light divider.
Inventors
- 👤 Takeshi Koyama
- 👤 Keiji Ohtaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:15
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/0006; G02B3/0037; G02B3/0043; G02B3/0056; G02B7/00; G02B7/28; G02B7/34; G02B7/346
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
151 words
An apparatus for detecting the focus adjusted state of an objective optical system, comprising: a plurality of pattern forming optical means for forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state by the use of energy passed through different areas of a pupil of the objective optical system; sensing means having a plurality of portions and producing a signal regarding a relative positional relation between the energy patterns; and optical means disposed between the objective optical system and said pattern forming optical means for asymmetrically varying optical paths passing through said areas of the pupil; said pattern forming optical means being arranged in the direction passing through said areas on the pupil and forming an asymmetrical shape with respect to the optic axis of said objective optical system, a first pattern forming optical means having a different shape from a second pattern forming optical means.
Claim 2
Independent Claim
151 words
An apparatus for detecting the focus adjusted state of an objective optical system, comprising: a plurality of pattern forming optical means for forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state by the use of energy passed through different areas of a pupil of the objective optical system; sensing means having a plurality of portions and producing a signal regarding a relative positional relation between the energy patterns; and optical means disposed between the objective optical system and said pattern forming optical means for asymmetrically varying optical paths passing through said areas of the pupil; said pattern forming optical means being arranged in the direction passing through said areas on the pupil and forming an asymmetrical shape with respect to the optic axis of said objective optical system, a first pattern forming optical means having a different shape from a second pattern forming optical means.
Claim 3
Dependent Claim
30 words
An apparatus according to claim 1, wherein said optical means comprises a light-transmitting plane parallel plate inclined with respect to the optical paths passing through said areas on the pupil.
Claim 4
Dependent Claim
25 words
An apparatus according to claim 2, wherein said light-transmitting plane parallel plate comprises a portion of a quick return mirror incorporated in a camera body.
Claim 5
Dependent Claim
29 words
An apparatus according to claim 1, wherein said plurality of pattern forming optical means comprise a plurality of convexo-planar lenses which differ in the inclination of their planar surfaces.
Claim 6
Dependent Claim
48 words
An apparatus according to claim 1, wherein each of said plurality of pattern forming optical means includes a biconvex lens having a second lens surface displaced relative to a first lens surface, the biconvex lenses each being different in a magnitude of displacement between the two lens surfaces.
Claim 7
Dependent Claim
22 words
An apparatus according to claim 1, wherein each of said plurality of pattern forming optical means has a stop and a lens.
Claim 8
Dependent Claim
76 words
An apparatus according to claim 1, further having another plurality of pattern forming optical means arranged in a direction differing from a direction of arrangement of said pattern forming optical means and forming separate energy patterns whose relative positional relation varies in conformity with the focus adjusted state of the objective optical system, and wherein said sensing means further has third and fourth portions each having a plurality of sensors and sensing said separate energy patterns.
Claim 9
Dependent Claim
166 words
A camera body used with an objective lens, comprising: a quick return mirror having a reflecting area for reflecting a part of a light beam from the objective lens toward a viewfinder and a transmitting area for refracting and transmitting another part of the light beam therethrough; an optical assembly having secondary imaging lenses optically arranged in a direction in which said quick return mirror is inclined for receiving the light beam transmitted through said transmitting area and forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state of the objective lens; and sensing means for receiving said energy patterns, said sensing means having two portions each having a plurality of sensors, said sensing means producing a signal regarding the relative positional relation between said energy patterns; said secondary imaging lenses being of an asymmetrical shape with respect to the optic axis of said objective lens, a first secondary imaging lens having a different shape from a second secondary imaging lens.
Claim 10
Dependent Claim
166 words
A camera body used with an objective lens, comprising: a quick return mirror having a reflecting area for reflecting a part of a light beam from the objective lens toward a viewfinder and a transmitting area for refracting and transmitting another part of the light beam therethrough; an optical assembly having secondary imaging lenses optically arranged in a direction in which said quick return mirror is inclined for receiving the light beam transmitted through said transmitting area and forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state of the objective lens; and sensing means for receiving said energy patterns, said sensing means having two portions each having a plurality of sensors, said sensing means producing a signal regarding the relative positional relation between said energy patterns; said secondary imaging lenses being of an asymmetrical shape with respect to the optic axis of said objective lens, a first secondary imaging lens having a different shape from a second secondary imaging lens.
Claim 11
Dependent Claim
24 words
A camera body according to claim 9, wherein said second imaging lenses include convexo-planar lenses which differ in the inclination of their planar surfaces.
Claim 12
Dependent Claim
43 words
A camera body according to claim 8, wherein said secondary imaging lenses each include a biconvex lens having a second lens surface displaced relative to a first lens surface, said biconvex lenses differing in the magnitude of the displacement between the lens surfaces.
Claim 13
Dependent Claim
31 words
A camera body according to claim 8, wherein said optical assembly has separate secondary imaging lenses arranged in a direction orthogonal to the direction of arrangement of said secondary imaging lenses.
Claim 14
Independent Claim
197 words
An apparatus for detecting the focus adjusted state of an objective optical system, comprising: a plurality of pattern forming optical means for forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state by the use of energy passed through different areas of a pupil of the objective optical system; sensing means having a plurality of portions and producing a signal regarding a relative positional relation between the energy patterns; and optical means disposed between the objective optical system and said pattern forming optical means for asymmetrically varying optical paths passing through said areas of the pupil, said optical means comprising a light-transmitting plane parallel plate inclined with respect to the optical paths passing through said areas of the pupil; and said pattern forming optical means being arranged in the direction passing through said areas of the pupil and forming an asymmetrical shape with respect to the optic axis of said objective optical system, a first pattern forming optical means having a different shape from a second pattern forming optical means, said plurality of pattern forming optical means comprising a plurality of convexo-planar lenses which differ in the inclination of their planar surfaces.
Claim 15
Independent Claim
197 words
An apparatus for detecting the focus adjusted state of an objective optical system, comprising: a plurality of pattern forming optical means for forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state by the use of energy passed through different areas of a pupil of the objective optical system; sensing means having a plurality of portions and producing a signal regarding a relative positional relation between the energy patterns; and optical means disposed between the objective optical system and said pattern forming optical means for asymmetrically varying optical paths passing through said areas of the pupil, said optical means comprising a light-transmitting plane parallel plate inclined with respect to the optical paths passing through said areas of the pupil; and said pattern forming optical means being arranged in the direction passing through said areas of the pupil and forming an asymmetrical shape with respect to the optic axis of said objective optical system, a first pattern forming optical means having a different shape from a second pattern forming optical means, said plurality of pattern forming optical means comprising a plurality of convexo-planar lenses which differ in the inclination of their planar surfaces.
Claim 16
Independent Claim
216 words
An apparatus for detecting the focus adjusted state of an objective optical system, comprising: a plurality of pattern forming optical means for forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state by the use of energy passed through different areas of a pupil of the objective optical system; sensing means having a plurality of portions and producing a signal regarding a relative positional relation between the energy patterns; and optical means disposed between the objective optical system and said pattern forming optical means for asymmetrically varying optical paths passing through said areas of the pupil, said optical means comprising a light-transmitting plane parallel plate inclined with respect to the optical paths passing through said areas of the pupil; and said pattern forming optical means being arranged in the direction passing through said areas of the pupil and forming an asymmetrical shape with respect to the optic axis of said objective optical system, a first pattern forming optical means having a different shape from a second pattern forming optical means, each of said plurality of pattern forming optical means including a biconvex lens having a second lens surface displaced relative to a first lens surface, the biconvex lenses each being different in a magnitude of displacement between the two lens surfaces.
Claim 17
Independent Claim
216 words
An apparatus for detecting the focus adjusted state of an objective optical system, comprising: a plurality of pattern forming optical means for forming energy patterns whose relative positional relation varies in conformity with the focus adjusted state by the use of energy passed through different areas of a pupil of the objective optical system; sensing means having a plurality of portions and producing a signal regarding a relative positional relation between the energy patterns; and optical means disposed between the objective optical system and said pattern forming optical means for asymmetrically varying optical paths passing through said areas of the pupil, said optical means comprising a light-transmitting plane parallel plate inclined with respect to the optical paths passing through said areas of the pupil; and said pattern forming optical means being arranged in the direction passing through said areas of the pupil and forming an asymmetrical shape with respect to the optic axis of said objective optical system, a first pattern forming optical means having a different shape from a second pattern forming optical means, each of said plurality of pattern forming optical means including a biconvex lens having a second lens surface displaced relative to a first lens surface, the biconvex lenses each being different in a magnitude of displacement between the two lens surfaces.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
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