Rechargeable camera having operational inhibit of a flash unit power storage circuit during recharging

• US 5,602,458 A
• Filed: 10/05/1995
• Issued: 02/11/1997
• Est. Priority Date: 08/16/1993
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Dowe, David R.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/539,456
• Time in Patent Office: 495 Days
• Field of Search: 354/484, 320/2, 320/5, 320/29, 320/27, 320/9, 320/49, 320/11, 320/37, 320/38, 320/47
• US Class Current: 396/205
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: Y10S 320/10 Nonbattery load controls charging

Abstract

A rechargeable photographic camera includes an interlock circuit that automatically inhibits operation of the camera flash when the camera is mated with a charging cradle, regardless of the condition of a manual on-off flash switch. The rechargeable battery of the camera therefore is assured of receiving a full charging current even if the flash unit is left on when the camera is mated with the charging cradle.

Claims

1. A rechargeable camera comprising:

a camera power switch selectively operable between an "on" position and an "off" position;

a battery circuit that receives electrical energy from a camera secondary battery;

a camera flash unit having a flash tube and a power storage circuit that includes an oscillator transistor and a flash trigger capacitor that receives and stores electrical energy from the battery circuit via the oscillator transistor when the camera power switch is in the "on" position such that the flash trigger capacitor can release the stored electrical energy to power the flash tube;

a recharging connector adapted to mate with a charging device and thereby receive electrical energy from the charging device and provide the electrical energy to the battery circuit, wherein;

the power storage circuit oscillator transistor is automatically grounded if the camera power switch is in the "on" and the recharging connector is mated with the charging device, thereby placing the oscillator transistor in a non-conducting condition and preventing the flash trigger capacitor from receiving and storing electrical energy from the battery circuit and permitting the secondary battery to receive the charging electrical energy instead.

2. A rechargeable camera system comprising:

a charging cradle that provides electrical energy; and

a camera having

an objective lens,

a shutter button,

a battery circuit that receives electrical energy from a camera battery,

a flash unit having a flash tube and a power storage circuit that stores electrical energy from the battery circuit and provides it to the flash tube, the power storage circuit including an energy storage device in which the electrical energy is stored and at least one switching transistor that directs electrical energy from the battery circuit to the energy storage device,

a recharging connector adapted to mate with the charging cradle and thereby receive electrical energy from the charging cradle that it provides to the camera battery of the battery circuit, and

a power switch operable between an "on" condition and an "off" condition such that the power switch directs electrical energy from the battery circuit to the power storage circuit when the power switch is in the "on" position and directs electrical energy from the recharging connector to the battery circuit when the power switch is in the "off" position;

wherein;

the power storage circuit further includes biasing means for placing the switching transistor into a non-conducting condition in response to the electrical energy received from the battery circuit when the power switch is in the "on" position and the recharging connector is mated with the charging cradle, thereby placing the power storage circuit in an inoperative condition and preventing the power storage circuit from providing electrical energy to the flash tube.

3. A rechargeable camera system as defined in claim 2, wherein the oscillator transistor includes an emitter and collector that are connected between the flash tube and the recharging connector such that the oscillator transistor is placed in a non-conductive condition by a diode ground connection from the oscillator transistor base to ground when the recharging connector is mated with the charging cradle.