Photographic operation control circuit for camera

• US 4,458,996 A
• Filed: 12/20/1979
• Issued: 07/10/1984
• Est. Priority Date: 12/25/1978
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Taguchi, Tetsuya, Tamura, Shuichi, Ito, Fumio, Harigaya, Isao, Hirohata, Michio, Matsuda, Mutsuhide
• Primary Examiner(s): Rubinson, G. Z.
• Assistant Examiner(s): Brady, W. J.
• Application Number:
  US06/105,659
• Time in Patent Office: 1,664 Days
• Field of Search: 354/173, 354/60 R, 354/50, 354/51, 354/171, 354/60 L, 354/60 E, 354/268, 354/289, 354/234, 354/235
• US Class Current: 396/48
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67
• CPC Class Codes: G03B 17/18 Signals indicating condition of a camera member or suitability of light indicating depth of field G03B13/30
• CPC Class Codes: G03B 19/12 Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror

Abstract

In the disclosed camera exposure control, data recording and film winding are performed sequentially and the system is protected from battery voltage drop arising from the effective increase in consumption of electrical energy necessary to make each exposure as compared with the ordinary camera, by detecting the battery level upon occurrence of a prescribed phase of the operating cycle. In one embodiment, the battery is also checked at a subsequent step of the cycle (for example, film winding operation is permitted only when the battery level is above the predetermined level). According to an embodiment of the invention, a sequence control circuit controls the photographic operation sequentially.

Claims

1. A camera for controlling at least an exposure operation and a film winding operation, comprising:

(a) a control circuit connectable to a power supply source and having an exposure control circuit for controlling the exposure operation and a film winding circuit for controlling the film winding operation;

(b) a voltage detection circuit for detecting the voltage of the power supply source, said voltage detection circuit being arranged to become operative upon completion of the exposure operation by the exposure control circuit and to become inoperative before the film winding operation begins; and

(c) warning means for producing a warning when a drop in voltage is detected by the voltage detection circuit.

2. A camera comprising:

(a) an exposure control circuit connectable to a power source for controlling an exposure;

(b) a voltage detecting circuit for detecting the voltage of the power source, said detecting circuit being arranged to become operative upon completion of an exposure control operation by the exposure control circuit; and

(c) warning means for giving a warning when a drop in voltage is detected by said detecting circuit.

3. A camera comprising:

(a) a shutter time control circuit for performing a shutter time control operation so as to control the shutter time;

(b) a film winding circuit connectable to a power source for performing a film winding operation and for becoming operative after the shutter time control operation of said shutter time control circuit has finished;

(c) a voltage detecting circuit for detecting the voltage from the power source and for becoming operative after the shutter time control operation has finished; and

(d) inhibiting means for inhibiting actuation of said film winding circuit when a drop in the voltage of the power supply source is detected by said voltage detecting circuit.

4. A voltage detection device for a camera which sequentially controls the various kinds of photographic operations comprising:

(a) a voltage detection circuit for detecting the voltage from a power supply source;

(b) a control circuit for rendering said voltage detection circuit operative upon completion of one photographic operation and inoperative before another photographic operation begins; and

(c) warning means for performing a warning operation when a voltage drop is detected by said voltage detection circuit.

5. A camera for controlling at least exposure and film winding operations, comprising:

(a) a control circuit connectable to a power supply source and having an exposure control circuit for controlling the exposure operation and a film winding circuit for controlling the film winding operation;

(b) a voltage detection circuit for detecting the voltage of the power supply source, said voltage detecting circuit being arranged to become operative upon completion of the exposure operation by the exposure control circuit and to become inoperative before the film winding operation begins; and

(c) inhibiting means for inhibiting the operation of the film winding circuit when a drop in voltage is detected by the voltage detection circuit.

6. A voltage detection device for a camera which sequentially controls various kinds of photographic operations, said device comprising:

(a) a voltage detection circuit for detecting voltage from a power supply source;

(b) a control circuit for rendering said voltage detection circuit operative upon completion of one photographic operation and inoperative before another photographic operation begins; and

(c) inhibiting means for inhibiting the operation of said other photographic operation when a drop in voltage of the power supply source is detected by said voltage detection circuit.