Patent US3683777A successfully refreshed from Google Patents.
US3683777A
Expired / Lapsed
US
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Automatic focus control device for photographic cameras
Assignee: Ricoh Co Ltd
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Filing: 1970-10-06
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Granted: 1972-08-15
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Expires: 1990-10-06
Abstract
Abstract An automatic focus control device for including a distance setting ring for focusing a taking lens, and an adjusting ring for a light receiving lens, a shutter operating button and a shutter release member includes a rack member engaged with external gear teeth on the setting ring and mounted for longitudinal reciprocation. A drive slide is mounted parallel to the rack member for longitudinal reciprocation, and a spring biases the slide toward a shutter release member. A disk movable in accordance with advance of the film operates a lever to conjointly displace both the rack member and the slide against the bias of the spring and a position where the rack member and the slide are releasably latched by locking means which is released by the shutter operating button. A catch on the slide engages a laterally extending pin on the rack member so that the rack member is moved conjointly with the slide when the shutter button is operated. An electromagnet is operable to release this latch member and receives an electric signal from photoelectric transducers associated with the light receiving lens and providing an electric output signal corresponding to the distance of a subject from the camera. When the subject is in proper focus, the electromagnet is energized to release the latch so that the rack member remains stationary while the slide continues its movement to operate the shutter release.
Inventors
- 👤 Fumihiro Miyagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:20
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
265 words
An automatic focus control device, for photographic cameras of the type including a rotatable distance setting ring for focusing a taking lens, an adjusting ring for a light receiving lens, a shutter operating button and a shutter release member, said device comprising, in combination, a movable member operable to rotate said distance setting ring to focus the taking lens; a drive member movable in the same direction as said movable member; means biasing said drive member to move in one direction; means operable to move both said members conjointly in the direction opposite to said one direction against the bias of said biasing means; releaseable locking means locking at least said drive member in a predetermined position responsive to said conjoint movement; interengaging means on said members operable to move said movable member in slaved relation to movement of said drive member by said biasing means, upon release of said locking means; signal producing means coupled to said distance setting ring and producing an electrical signal responsive to light reflected from a subject, and received by said signal producing means, in accordance with the distance between the camera and a subject; and electrically operable means connected to said signal producing means and operable by said electrical signal, when the subject is in correct focus, to release said interengageable means for continued movement of said drive member by said biasing means in said one direction and independently of said movable member, which latter remains stationary in a position in which said distance setting ring has been rotated to adjust the taking lens to the correct focus.
Claim 2
Dependent Claim
265 words
An automatic focus control device, for photographic cameras of the type including a rotatable distance setting ring for focusing a taking lens, an adjusting ring for a light receiving lens, a shutter operating button and a shutter release member, said device comprising, in combination, a movable member operable to rotate said distance setting ring to focus the taking lens; a drive member movable in the same direction as said movable member; means biasing said drive member to move in one direction; means operable to move both said members conjointly in the direction opposite to said one direction against the bias of said biasing means; releaseable locking means locking at least said drive member in a predetermined position responsive to said conjoint movement; interengaging means on said members operable to move said movable member in slaved relation to movement of said drive member by said biasing means, upon release of said locking means; signal producing means coupled to said distance setting ring and producing an electrical signal responsive to light reflected from a subject, and received by said signal producing means, in accordance with the distance between the camera and a subject; and electrically operable means connected to said signal producing means and operable by said electrical signal, when the subject is in correct focus, to release said interengageable means for continued movement of said drive member by said biasing means in said one direction and independently of said movable member, which latter remains stationary in a position in which said distance setting ring has been rotated to adjust the taking lens to the correct focus.
Claim 3
Dependent Claim
46 words
An automatic focus control device for photographic cameras, as claimed in claim 1, in which said locking means is released responsive to operation of a shutter button; said drive member at the termination of said continued movement, operating a shutter release member to take a picture.
Claim 4
Dependent Claim
38 words
An automatic focus control device for photographic cameras, as claimed in claim 1, in which said interengaging means comprises a latch on one of said members and releasably engageable with a pin on the other of said members.
Claim 5
Dependent Claim
51 words
An automatic focus control device for photographic cameras, as claimed in claim 1, in which said movable member comprises a longitudInally reciprocable rack meshing with gear teeth on the external periphery of said setting ring; said drive member comprising a slide adjacent said rack and longitudinally reciprocable parallel to said rack.
Claim 6
Dependent Claim
62 words
An automatic focus control device for photographic cameras, as claimed in claim 4, in which said interengaging means comprises a hook pivotally mounted on said slide and releasably engageable with a pin on said rack extending laterally toward said slide; said electrically operable means comprising an electromagnet on said slide and operable, when energized, to pivot said hook to release said pin.
Claim 7
Dependent Claim
70 words
An automatic focus control device for photographic cameras, as claimed in claim 5, in which at least said slide is formed with a projection on one end; said releaseable locking means comprising a pivoted latch engageable with said projection to restrain said slide and said rack against movement under the bias of said biasing means; said pivoted latch being releasable from said projection by operation of the shutter operating button.
Claim 8
Dependent Claim
63 words
An automatic focus control device for photographic cameras, as claimed in claim 6, including means engageable with said rack and said slide, and operable, responsive to advance of the film in the camera, to move said rack and said slide against the bias of said biasing means and as a conjoint unit to a position in which said pivoted latch engages said projection.
Claim 9
Dependent Claim
62 words
An automatic focus control device for photographic cameras, as claimed in claim 1, including means coupling said distance setting ring and said adjusting ring for conjoint rotation; said signal producting means including a pair of photoelectric transducers arranged on respective opposite sides of the focal plane of said light receiving lens and having light passing through said light receiving lens impinge thereon.
Claim 10
Dependent Claim
94 words
An automatic focus control device for photographic cameras, as claimed in claim 8, in which said electrically operable means comprises an electromagnet operable, when energized, to release said interengaging means; a second pair of photoelectric transducers connected in a bridge circuit with said first mentioned photoelectric transducers; a source of potential connected to the input terminals of said bridge circuit; and a transistorized circuit connected to the output terminals of said bridge circuit; said electromagnet being connected in the output of said transistorized circuit and being energized responsive to balancing of said bridge circuit.
Claim 11
Dependent Claim
171 words
An automatic focus control device for photographic cameras, as claimed in claim 9, in which said transistorized circuit includes a pair of first transistors having their bases connected to respective output terminals of said bridge circuit, the output circuits of said first transistors being connected, in opposition to each other, to the base of a second transistor; a second source of potential connected to the output circuit of said second transistor; a third transistor connected, in series with said electromagnet, across said second source of potential and having its base connected to the output circuit of said second transistor; said second transistor being triggered conductive by one of said first transistors when said bridge circuit is unbalanced to form a current by-pass for the base of said third transistor; said second transistor, responsive to balancing of said bridge, being triggered to a blocking state for flow of current from said second source of potential to the base of said third transistor to trigger said third transistor conductive to energize said electromagnet.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |