Battery recharging system and method for electronic cameras

• US 6,774,946 B1
• Filed: 07/28/1999
• Issued: 08/10/2004
• Est. Priority Date: 07/29/1998
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Misawa, Takeshi, Yamazaki, Akihisa
• Primary Examiner(s): Vu, Ngoc-Yen, Vu, Ngoc-Yen
• Assistant Examiner(s): VILLECCO, JOHN M
• Application Number:
  US09/362,404
• Time in Patent Office: 1,840 Days
• Field of Search: 348/208.16, 348/333.07, 348/333.13, 348/372, 348/373, 348/374, 348/375, 250/208.1, 396/278, 396/279, 396/280, 396/301, 396/303, 396/304
• US Class Current: 348/372
• 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: H04N 23/50 Constructional details
• CPC Class Codes: H04N 23/651 for reducing power consumption by affecting camera operations, e.g. sleep mode, hibernation mode or power off of selective parts of the camera
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals

Abstract

A rechargeable battery in an electronic camera is charged without additionally providing the camera with a power generating device. When a power-supply switch of the camera is turned off, a diaphragm and a shutter are opened and a taking lens is controlled so as to set focus to infinity. Signal charge that has accumulated in a CCD is output as a charging current, and the rechargeable battery is charged by a power-supply control circuit.

Claims

1. An electronic camera equipped with a solid-state electronic image sensing device for sensing the image of a subject and outputting a video signal representing the image of a subject, comprising:

a power-supply switch for controlling a power supply to turn the power supply on and off;

a power-supply switch discrimination device for determining whether said power-supply has been turned off;

a charging circuit for charging a rechargeable battery;

a current discrimination device for determining whether a charging current obtained from a signal charge that has accumulated in the solid-state electronic image sensing device is greater than a predetermined current; and

a charging control device, responsive to a determination by said power-supply switch has been turned off, for controlling said charging circuit so as to charge the rechargeable battery using the charging current if said current discrimination device determines that the charging current is greater than the predetermined current.

2. The camera according to claim 1, further comprising:

a diaphragm for limiting the quantity of light that impinges upon the solid-state electronic image sensing device; and

a diaphragm control device for opening said diaphragm in response to a determination by said power-supply switch discrimination device that said power supply has been turned off.

3. The camera according to claim 1, further comprising:

a mechanical shutter for limiting length of time during which light impinges upon the solid-state electronic image sensing device; and

a shutter control device for opening said mechanical shutter in response to a determination by said power-supply switch discrimination device that said power supply has been turned off.

4. The camera according to claim 1, further comprising:

a taking lens system for forming the image of a subject on a light-receiving surface of the slid-state electronic image sensing device;

a focusing mechanism for controlling said taking lens system so as to focus the image of the subject on the light-receiving surface of the slid-state electronic image sensing device; and

a device for controlling said focusing mechanism, in response to a determination by said power-supply switch discrimination device that said power supply has been turned off, in such a manner that the image of the subject is formed at infinity.

5. The camera according to claim 1, wherein said camera has a back side formed to include a light-transmitting window, a light shielding member is freely attachable to said window, and the solid-state electronic image sensing device has an underside that is fixed to said window via a transparent substrate.

6. The camera according to claim 5, wherein said light shielding member is equipped with a display device for displaying the image of the subject represented by the video signal output from the solid-state electronic image sensing device.

7. The camera according to claim 5, wherein said light shielding member is removably attached to the front side of the camera.

8. A method of controlling the operation of an electronic camera equipped with a solid-state electronic image sensing device for sensing the image of a subject and outputting a video signal representing the image of a subject, comprising the steps of:

discriminating whether said power-supply, which is for controlling a power supply to turn the power supply on and off, has been turned off;

determining whether a charging current available from signal charges accumulated in the solid-state electronic image sensing device is greater than a predetermined current; and

charging a rechargeable battery using the charging current in response to turning off of the power-supply switch and in response to a determination that the charging current is greater than the predetermined current.

9. The method of claim 8, wherein the step of charging the rechargeable battery further comprises:

maximizing an amount of light energy received to charge the solid-state electronic image sensing device; and

minimizing an amount of current consumed by the camera.

10. The method of claim 9, wherein the step of minimizing the amount of current consumed comprises setting the camera in a sleep mode, wherein the predetermined current is a current amount consumed by the camera in the sleep mode.

11. The method of claim 10, wherein the electronic camera includes a display and wherein the predetermined current further includes current required to display an image on the display.

12. The method of claim 9, wherein the step of maximizing the amount of light energy received comprises at least one of opening a diaphragm of the camera, opening a shutter of the camera, or setting a focus of a taking lens to infinity.

13. The method of claim 12, wherein the electronic camera includes a detachable light shielding plate and wherein the step of maximizing the amount of light energy received further comprises detaching the light shielding plate from the camera.

14. The method of claim 8, wherein the electronic camera includes a detachable light shielding plate and wherein the method further comprises attaching the light shielding plate to a front of the electronic camera for protection.

15. An imaging apparatus operable for charging a rechargeable battery, comprising:

an image sensing device;

a charging circuit configured for charging the rechargeable battery using a charging current obtained from accumulated signal charges from said image sensing device;

a charging control device configured for controlling said charging circuit such that said charging circuit charges the rechargeable battery when said imaging apparatus is inactive and said charging current is greater than a predetermined current value.

16. The imaging apparatus of claim 15, wherein said predetermined current value is a current amount consumed by said imaging apparatus in a sleep mode.

17. The imaging apparatus according to claim 15, further comprising:

a diaphragm configured for controlling a quantity of light impinging upon image sensing device; and

a diaphragm control device configured for controlling an opening of said diaphragm to a predetermined opening amount when said imaging apparatus is inactive.

18. The imaging apparatus according to claim 17, wherein the predetermined opening amount is a maximum opening amount.

19. The imaging apparatus according to claim 15, further comprising:

a mechanical shutter configured for controlling length of time during which light impinges upon said image sensing device; and

a shutter control device configured for opening said mechanical shutter when said imaging apparatus is inactive.

20. The imaging apparatus according to claim 15, further comprising:

a lens system configured for forming an image on said image sensing device; and

a lens control device configured for controlling focusing of said lens system to a predetermined focus value when said imaging apparatus is inactive.

21. The imaging apparatus according to claim 20, wherein the predetermined focus value is infinity.