Indication control unit for an electronically controlled camera

• US 5,012,272 A
• Filed: 07/26/1989
• Issued: 04/30/1991
• Est. Priority Date: 06/30/1988
• Status: Expired due to Term

• Current Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Original Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Inventors: Kobayashi, Takeo, Numako, Norio, Nagai, Katsutoshi, Tabata, Yasushi
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Spyrou, Cassandra C.
• Application Number:
  US07/385,531
• Time in Patent Office: 643 Days
• Field of Search: 354/171, 354/465, 354/468, 354/471, 354/212, 354/215, 354/289.1, 354/484, 354/21
• US Class Current: 396/284
• CPC Class Codes: G02B 7/102 controlled by a microcomputer cameras with interchangeable lenses G03B17/14
• CPC Class Codes: G02B 7/282 Autofocusing of zoom lenses
• CPC Class Codes: G03B 1/56 Threading; Loop forming
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 17/12 with means for supporting objectives, supplementary lenses, filters, masks, or turrets
• CPC Class Codes: G03B 17/14 interchangeably
• 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 17/20 visible in viewfinder
• CPC Class Codes: G03B 17/425 motor drive cameras
• CPC Class Codes: G03B 2215/0503 Built-in units
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: G03B 7/091 Digital circuits
• CPC Class Codes: G03B 7/26 Power supplies; Circuitry or arrangement to switch on the power source; Circuitry to check the power source voltage
• CPC Class Codes: H03M 1/285 of the unit Hamming distance type, e.g. Gray code

Abstract

An indication control unit for an electronically controlled camera. The indication control unit includes a display for indicating photographic information; electrical power supply for the indicator unit; a film presence detecting device; a mechanism for switching the camera between an operable, picture taking state and an inoperable, non-picture taking state; and a mechanism for disabling the electrical power supply if the camera is in the inoperable, non-picture taking state and the film presence detecting device fails to detect film in the camera. With the present invention, the amount of electrical power that is consumed by the indication control unit, which can include a liquid crystal display, for example, is minimized.

Claims

1. An indication control unit for an electronically controlled camera, comprising:

means for indicating photographic information;

means for supplying electrical power to said indicator means for indicating;

means for detecting the presence of film in said camera;

means for switching said camera between an operable, picture taking state and an inoperable, non-picture taking state; and

means for disabling said means for supplying electrical power if said camera is in said inoperable, non-picture taking state and said film presence detecting means fails to detect film in said camera.

2. The indication control unit according to claim 1, wherein said means for indicating comprises a liquid crystal display unit.

3. The indication control unit according to claim 2, wherein said means for disabling includes a field effect transistor that is electrically connected between said means for supplying electrical power and said liquid crystal display unit.

4. The indication control unit according to claim 3, wherein said film presence detecting means generates a first signal indicating that said film is not in said camera, and said switching means generates a second signal indicating that said camera is in said inoperable, non-picture taking state, said field effect transistor being operable to interrupt said electrical connection between said means for supplying electrical power and said liquid crystal display unit when said first and second signals are both sent to said field effect transistor.

5. The indication control unit according to claim 4, wherein said camera further comprises:

a film compartment; and

a film compartment cover, said film presence detecting means comprising a sensor that changes from a first state to a second state when said film compartment cover is in a closed position and said film that is withdrawn out of a film cartridge located in said film compartment interacts with said sensor.

6. The indication control unit according to claim 5, wherein said sensor comprises a push-button switch that is depressed when said film is positioned over said switch and said film compartment cover is in said closed position.

7. A method of controlling the operation of an indicator unit of an electronically controlled camera comprising the steps of:

determining the presence of film in said camera; and

disabling the operation of the indicator unit of said camera if said camera fails to detect the presence of film in the camera and said camera is in an inoperable, non-picture taking state of operation.

8. The method according to claim 7, wherein the step of disabling the operation of the indicator unit comprises the step of instructing a drive voltage generator to stop supplying electrical power to said indicator unit.

9. An indicator control unit for an electronically controlled camera, comprising:

means for displaying photographic data;

means for determining the presence of film in said camera;

means for determining the state of operation of said camera; and

means for disabling the operation of said display means when said film presence means fails to detect film in said camera and said camera is determined to be in an inoperable, non-picture taking state of operation.

10. The indicator control unit according to claim 9, wherein said disabling means comprises means for eliminating electrical power to said display means.

11. The indicator control unit according to claim 9, wherein said disabling means includes a field effect transistor that is operable to interrupt the supply of electrical power to said display means.

12. The indicator control unit according to claim 11, wherein said display means comprises a liquid crystal display unit.

13. The indicator control unit according to claim 9, wherein said display means comprises a liquid crystal display unit.

14. The indicator control unit according to claim 9, wherein said film presence means comprises a sensor that determines whether said film is at a predetermined position in a film advancing path of said camera.

15. The indicator control unit according to claim 9, wherein said film presence means comprises a sensor that determines whether said film is at a predetermined position in a film advancing path of said camera and whether a back cover of said camera is in a closed position.

16. The indicator control unit according to claim 14, wherein said sensor comprises a switch that has an output that changes from a first state to a second state when the presence of said film is detected.

17. The indicator control unit according to claim 15, wherein said sensor comprises a switch that changes from first state to a second state when said film is at said predetermined position and said back cover is in said closed position.

18. The indicator control unit according to claim 16, wherein said switch comprises a push-button switch that is depressed by said film.

19. The indicator control unit according to claim 18, wherein said switch comprises a push-button switch that is depressed by said film at said predetermined position when said back cover is in said closed position.

20. The indicator control unit according to claim 9, wherein said operation state determining means determines whether a power switch in said cover is in an off position.

21. The indicator control unit according to claim 9, wherein said operation state determining means generates a drive voltage signal to control said disabling means.

22. The indicator control unit according to claim 21, wherein said drive voltage signal is dependent upon a signal produced by said film presence determining means and said operation state determining means.

23. The indicator control unit according to claim 22, wherein said drive voltage signal is supplied to a drive voltage generator that operates a drive circuit that controls said display means.

24. The indicator control unit according to claim 23, transistor that is operable to interrupt the supply of electrical power to said drive circuit.