Patent · US Expired

Battery check device for a camera

US5528335A · kind A · utility

7Cited by
2References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 26, 1994
Grant dateJun 18, 1996
Priority date
Expiry dateSep 26, 2014

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B7/26
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A battery check device, suitable for use in a camera, for reliably checking the essential capacity of a battery power source without affecting the voltage recovery of the battery power source after a long period of non-use. The battery check device monitors a starting switch, for example, a main switch or a release button, with a timer circuit and compares a switch interval between a previous time the starting switch was set ON and a present time the starting switch is set ON with a predetermined time. When the switch interval is within the predetermined time, a battery check circuit checks the power supply capacity of the battery power source using a light load circuit. When the interval is not within the predetermined time, the battery check circuit checks the power supply capacity of the battery using a heavy load circuit.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.