Patent · US Expired

Stopwatch

US5151885A · kind A · utility

7Cited by
5References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 26, 1992
Grant dateSep 29, 1992
Priority date
Expiry dateMar 26, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG04F10/00
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A stopwatch according to the present invention can measure a lap time by the operation of a lap switch of a key input portion and stores the measured lap time in a RAM. When the lap switch is operated, a minute hand is immediately moved to a position of 0 o'clock, and is started its rotation from the position of 0 o'clock. The hand is rotated at such speed that the hand arrives at a position of 10 o'clock after the preceding lap time stored in the RAM is elapsed. In order to rotate the hand at the above described speed, a microprocessor unit calculates the time interval to supply pulse signal to a step motor. Since the hand is moved from the position of 0 o'clock to the position of 10 o'clock at the above described speed, percentage of the lap time being measured at present with respect to the preceding lap time can be immediately known.

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