US3813680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Camera having incrementally controllable aperture
Assignee: Agfa Gevaert AG
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Filing: 1973-03-23
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Granted: 1974-05-28
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Expires: 1993-03-23
Abstract
Abstract A camera has light sensitive means which furnish a signal corresponding to the light available for an exposure. The camera has a diaphragm having an adjustable aperture. Electromagnetic step switch means are coupled to the diaphragm for changing the size of the aperture a predetermined increment in response to a predetermined number of control pulses. An astable multivibrator furnishes a sequence of control pulses. A differential amplifier furnishes an output signal when the size of the aperture differs from the desired size corresponding to the exposure signal. A first gate transmits the control pulses from the astable multivibrator to the input of the electronic step switch means when the output signal of the differential amplifier is positive, while a second gate transmits control pulses from the astable multivibrator to the electromagnetic step switch means when the differential amplifier output is negative. The two gates have outputs so-connected to the step switch means that an armature which is part of the step switch means rotates in a first direction in response to pulses applied from the first gate and in the opposite direction in response to pulses applied through the second gate. The aperture is opened further for one direction of rotation of the armature and closes when the armature rotates in the opposite direction.
Inventors
- 👤 E Wagensonner
- 👤 A Winkler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:17
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/085
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
193 words
In a camera having light sensitive means for furnishing an exposure signal corresponding to the available light for an exposure, and having a diaphragm having an adjustable aperture, an arrangement for adjusting the size of said aperture to a desired size corresponding to said exposure signal, comprising, in combination, first means coupled to said light sensitive means and to said diaphragm, for furnishing a first output signal when said actual size of said aperture is less than said desired size and for furnishing a second output signal when said actual size of said aperture exceeds said desired size; electromagnetic step switch means operable in a first or second direction for, respectively, increasing and decreasing the size of said aperture a predetermined increment in response to a predetermined number of control pulses; and control circuit means connected to said electromangetic step switch means and said first means for furnishing said control pulses for operating said electromagnetic step switch means in said first direction in response to said first output signal and for furnishing said control pulses for operating said electromagnetic step switch means in said second direction in response to said second output signal.
Claim 2
Dependent Claim
193 words
In a camera having light sensitive means for furnishing an exposure signal corresponding to the available light for an exposure, and having a diaphragm having an adjustable aperture, an arrangement for adjusting the size of said aperture to a desired size corresponding to said exposure signal, comprising, in combination, first means coupled to said light sensitive means and to said diaphragm, for furnishing a first output signal when said actual size of said aperture is less than said desired size and for furnishing a second output signal when said actual size of said aperture exceeds said desired size; electromagnetic step switch means operable in a first or second direction for, respectively, increasing and decreasing the size of said aperture a predetermined increment in response to a predetermined number of control pulses; and control circuit means connected to said electromangetic step switch means and said first means for furnishing said control pulses for operating said electromagnetic step switch means in said first direction in response to said first output signal and for furnishing said control pulses for operating said electromagnetic step switch means in said second direction in response to said second output signal.
Claim 3
Dependent Claim
57 words
An arrangement as set forth in claim 1, wherein said first means comprise a differential amplifier for furnishing a differential amplifier output signal; and wherein said first output signal is a differential amplifier signal having a first polarity and said second output signal is a differential amplifier signal having a second polarity opposite to said first polarity.
Claim 4
Dependent Claim
77 words
An arrangement as set forth in claim 2, wherein said control circuit means comprise pulse generator means for furnishing a pulse sequence, and first and second gating means each having an input connected to said pulse generator means and having, respectively, a first and second gating output for furnishing a first and second pulse sequence at said first and second gating outputs respectively in response to differential amplifier output signals having said first and second polarity respectively.
Claim 5
Dependent Claim
32 words
An arrangement as set forth in claim 3, wherein said first and second gating means respectively comprise a first and second emitter follower stage, having, respectively, an npn and a pnp transistor.
Claim 6
Dependent Claim
174 words
An arrangement as set forth in claim 4, further comprising a first source of electrical energy having a positive and negative output terminal, a second source of electrical energy having a positive and negative output terminal, means connecting said negative output terminal of said first source of electrical energy to said positive output terminal of said second source of electrical energy; and wherein said differential amplifier means has a positive supply line connected to said positive output terminal of said first source of electrical energy and a negative supply line connected to said negative output terminal of said second source of electrical energy; wherein said pluse generator means has a positive supply terminal connected to said positive terminal of said first source of electrical energy and a negative supply input connected to said negative terminal of said second source of electrical energy; and wherein said first and second gating means have a common supply input connected to said common point and a common control input connected to the output of said differential amplifier means.
Claim 7
Dependent Claim
119 words
An arrangement as set forth in claim 3, wherein said electronic step switch means comprise an armature, a plurality of electromagnetic coils arranged radially to said armature, and coil energizing circuit means connected to said coils and said first and second gating outputs for energizing said coils in a first predetermined sequence in response to said pulse sequence received at said first gating output and in a second predetermined sequence in response to the pulse sequence received aT said second gating output, in such a manner that said amrature rotates in a first direction in response to pulses received at said first gating output and in a second direction in response to pulses received at said second gating output.
Claim 8
Dependent Claim
62 words
An arrangement as set forth in claim 6, wherein said coil energizing circuit means comprise a plurality of semi-conductor switch means each having a conductive state in response to a control signal applied thereto, each connected to a corresponding one of said coils in such a manner that said coil is energized when said semi-conductor switch means is in said conductive state.
Claim 9
Dependent Claim
51 words
An arrangement as set forth in claim 7, further comprising coupling means for intercoupling said semiconductor switch means in such a manner that each of said semi-conductor switch means is switched to the non-conductive state upon switching of the next subseqeunt one of said semi-conductor switch means to the conductive state.
Claim 10
Dependent Claim
71 words
An arrangement as set forth in claim 8, wherein said first and second pulse sequence each comprise a plurality of pulses; and wherein said armature rotates a predetermined angle in response to each of said pulses and wherein said electronic step switch means is coupled to said diaphragm means in such a manner that rotation of said predetermined angle changes said aperture size by a predetermined fraction of said predetermined increment.
Claim 11
Dependent Claim
17 words
An arrangement as set forth in claim 3, wherein said pulse generator means comprise an astable multivibrator.
Claim 12
Dependent Claim
28 words
An arrangement as set forth in claim 1, wherein said light sensitive means comprise light sensitive means positioned behind said diaphragm means in the direction of light propagation.
Claim 13
Dependent Claim
63 words
An arrnagment as set forth in claim 1, wherein said light sensitive means is positioned in front of said diaphragm means in the direction of light propagation; and wherein said means for furnishing an aperture signal comprise resistor means having a wiper arm mechanically coupled to said electromagnetic step switch means and electrically connected to said second input of said differential amplifier means.
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) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |