US3791272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic camera shutter controls with storage or pulse voltages
Assignee: Asahi Chemical Co Ltd
•
Filing: 1973-02-05
•
Granted: 1974-02-12
•
Expires: 1993-02-05
Abstract
Abstract An electrical structure for automatically controlling a camera shutter. The structure includes a pair of memory capacitors for respectively storing voltages in response to pulses received by these memory capacitors, and oscillators are respectively connected electrically with the capacitors for transmitting the pulses thereto. One of the oscillators is operated in accordance with variable factors such as brightness at the object to be photographed, diaphragm setting, and film speed, while the other of the oscillators is operated according to a predetermined reference factor. The memory capacitor which stores a voltage in accordance with this reference factor has its operation started when the camera shutter opens and the voltage of this latter memory capacitor is compared with the voltage of the other memory capacitor. When these voltages have a given relationship with respect to each other a signal is automatically transmitted to a structure which brings about closing of the shutter so as to terminate an exposure.
Inventors
- 👤 T Nobusawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:52
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
289 words
In an electrical structure for automatically controlling a camera shutter, a variable system including memory means for storing a voltage determined by a number of pulses received by said memory means, oscillator means electrically connected with said memory means for transmitting pulses thereto for determining the voltage stored thereby, and actuating means electrically connected with said oscillator means for actuating the latter to transmit to said memory means a number of pulses determined by variable factors such as brightness at the object to be photographed, film speed, and diaphragm setting, a reference system including a memory means for storing a voltage determined by pulses received by the latter memory means, an oscillator means electrically connected with said memory means of said reference system for transmitting pulses thereto, and actuating means electrically connected with said oscillator means of said reference system for actuating the latter to transmit pulses to said memory means of said reference system in accordance with a predetermined reference factor, starting means electrically connected with said actuating means of said reference system for starting the operation thereof upon opening of a camera shutter, comparing means electrically connected with both of said memory means for comparing with the voltage stored by said memory means of said variable system the voltage stored by said memory means of said reference system as the latter voltage builds, signaltransmitting means electrically connected with said comparing means for transmitting a signal therefrom whEn the voltage of said memory means of said reference system has a predetermined relationship with respect to the voltage of said memory means of said variable system, and signal-receiving means electrically connected with said signal-transmitting means for receiving said signal therefrom and initiating a shutter-closing operation upon receiving said signal.
Claim 2
Dependent Claim
289 words
In an electrical structure for automatically controlling a camera shutter, a variable system including memory means for storing a voltage determined by a number of pulses received by said memory means, oscillator means electrically connected with said memory means for transmitting pulses thereto for determining the voltage stored thereby, and actuating means electrically connected with said oscillator means for actuating the latter to transmit to said memory means a number of pulses determined by variable factors such as brightness at the object to be photographed, film speed, and diaphragm setting, a reference system including a memory means for storing a voltage determined by pulses received by the latter memory means, an oscillator means electrically connected with said memory means of said reference system for transmitting pulses thereto, and actuating means electrically connected with said oscillator means of said reference system for actuating the latter to transmit pulses to said memory means of said reference system in accordance with a predetermined reference factor, starting means electrically connected with said actuating means of said reference system for starting the operation thereof upon opening of a camera shutter, comparing means electrically connected with both of said memory means for comparing with the voltage stored by said memory means of said variable system the voltage stored by said memory means of said reference system as the latter voltage builds, signaltransmitting means electrically connected with said comparing means for transmitting a signal therefrom whEn the voltage of said memory means of said reference system has a predetermined relationship with respect to the voltage of said memory means of said variable system, and signal-receiving means electrically connected with said signal-transmitting means for receiving said signal therefrom and initiating a shutter-closing operation upon receiving said signal.
Claim 3
Dependent Claim
31 words
The combination of claim 1 and wherein said memory means of said reference system provides for the building voltage stored thereby a rate of increase which is at least approximately linear.
Claim 4
Dependent Claim
35 words
The combination of claim 1 and wherein a pair of logarithmic compression means are respectively connected electrically with said systems for providing at said pair of memory means compressed voltages to be stored thereby, respectively.
Claim 5
Dependent Claim
68 words
The combination of claim 1 and wherein said actuating means of said variable system includes an operating means electrically connected with said oscillator means of said variable system for operating the latter to produce pulses in accordance with one of said variable factors and a duration-determining means electrically connected with said operating means for determining the duration of operation thereof in accordance with another of said variable factors.
Claim 6
Dependent Claim
43 words
The combination of claim 4 and wherein said operating means includes a photosensitive means for responding to brightness at the object to be photographed and said operating means operating said oscillator means of said variable system at a frequency determined by said brightness.
Claim 7
Dependent Claim
54 words
The combination of claim 4 and wherein said duration-determining means includes a photosensitive means for responding to brightness at the object to be photographed for determining the duration of operation of said operating means in accordance with said brightness, said operating means operating said actuating means of said variable system at a constant frequency.
Claim 8
Dependent Claim
17 words
The combination of claim 1 and wherein at least one of said oscillator means includes a UJT.
Claim 9
Dependent Claim
17 words
The combination of claim 1 and wherein at least one of said oscillator means includes a multivibrator.
Claim 10
Dependent Claim
19 words
The combination of claim 1 and wherein at least one of said oscillator means includes an RC phase-shifting oscillator.
Claim 11
Dependent Claim
66 words
The combination of claim 1 and wherein a longarithmic-compression diode is electrically connected with said actuating means of said variable system for logarithmically compressing the voltage stored by said memory means of said variable system and wherein a logarithmic-compression diode is electrically connected with said memory of said reference system for logarithmically compressing the voltage stored thereby, so that said comparing means compares logarithmically compressed voltages.
Claim 12
Dependent Claim
116 words
The combination of claim 10 and wherein said actuating means of said variable system includes a photosensitive operating means electrically connected with said oscillator means of said variable system for oscillating the latter at a frequency determined by the brightness at the object to be photographed, said logarithmic-compression diode of said variable system being connected in series with said photosensitive operating means, and said actuating means of said variable system including a duration-determining means electrically connected with said operating means for determining the duration of operation thereof, said duration-determining means including a variable resistor which is adjustable in accordance with at least one of the variable factors other than brightness at the object to be photographed.
Claim 13
Dependent Claim
134 words
The combination of claim 10 and wherein said actuating means of said variable system includes an operating means electrically connected with said oscillator means of said variable system for operating said oscillator means, and said operating means including a variable resistor adjustable according to one of said variable factors other than brightness at the object to be photographed, for operating said oscillator means of said variable system at a frequency whiCh is constant and determined by the setting of said variable resistor, said logarithmic-compression diode of said variable system being connected in series with said variable resistor, and said actuating means of said variable system including a photosensitive duration-determining means electrically connected with said operating means for determining the duration of operation thereof in accordance with the brightness and the object to be photographed.
Claim 14
Dependent Claim
40 words
The combination of claim 1 and wherein a correction circuit means is electrically connected with at least one of said memory means for providing a feedback which corrects the voltage stored by said latter memory means into a linear form.
Claim 15
Dependent Claim
25 words
The combination of claim 13 and wherein said correction circuit means is in the form of a boot strap circuit which provides a positive feedback.
Claim 16
Dependent Claim
24 words
The combination of claim 13 and wherein said correction circuit means is in the form of a mirror circuit which provides a negative feedback.
Claim 17
Dependent Claim
46 words
The combination of claim 1 and wherein a multivibrator circuit means is electrically connected between said oscillator means and said memory means of at least one of said systems for regulating the form of the oscillation pulse received by said memory means of said one system.
Claim 18
Dependent Claim
21 words
The combination of claim 16 and wherein said multivibrator circuit means is in the form of a single stability multivibrator circuit.
Claim 19
Dependent Claim
54 words
The combination of claim 1 and wherein a correction circuit means and a pulse-form regulating circuit means are electrically connected with said memory means of at least one of said systems for respectively producing linearity in the voltage stored thereby and regulating the form of the oscillation pulse received by the latter memory 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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |