Digital time error measuring arrangement
AssigneeCitizen Watch Co., Ltd.
InventorsShingo Ichikawa, Hiroshi Yanagawa
Life of this patent
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Abstract
The invention resides in an improved time error measuring device or test bench for watches. The device includes a sensing microphone for sensing the stepping movement of the watch under test and in the form of a series of electric signal pulses. It further includes a range selector adapted for selecting a proper range depending upon the thus sensed stepping signal pulse series. Time error measuring means is utilized for detecting occasional time error of the watch by comparing the sensed stepping pulses with a standard clock pulse series and at the precision attributed to a selected measuring range. All these operations may be carried out in a fully automatic manner.
Claims11
A digital time error measuring device, comprising in combination, a) first means for sensing a watch signal from a watch under test;
- b) second means for amplifying said watch signal and converting it tinto pulses;
- c) a standard oscillator for generating a series of standard clock pulses;
- d) a preliminary measuring means adapted for operation by reception of said standard clock pulses for selecting and determining the most optimal respective one of predetermined measuring and displaying conditions and depending upon the difference between the frequency of said clock signal and the measured watch signal;
- e) main measuring means for measurement of time error of said watch signal and depending upon the measuring conditions selected and determined by said preliminary measuring means;
- and f) time error display means for display of measured results by main measuring means and depending upon the display condition selected and determined by said preliminary measuring means, wherein said first means for sensing a watch signal comprises sensing means for watch signals of a different physical nature comprising periodic stepping information of electrical field, magnetic field and mechanical vibration modes.
A digital time error measuring device, comprising in combination, a) first means for sensing a watch signal from a watch under test;
- b. second means for amplifying said watch signal and converting it into pulses;
- c. a standard oscillator for generating a series of standard clock pulses;
- d. a preliminary measuring means adapted for operation by reception of the measured watch signal thereby determining one of predetermined measuring and displaying conditions;
- e) main measuring means for measurement of time error of said watch signal and depending upon the measuring conditions selected and determined by said preliminary measuring means;
- and f) time error display means for display of measured results by said main measuring means and depending upon the display condition selected and determined by said preliminary measuring means, said preliminary measuring means comprising a pulse generating circuit adapted for starting upon reception of said measured watch signal and for delivery of a plurality of gate signal pulses each comprising two or more seconds pulses plus or minus a measurable error time length and means for selecting and storing a gate signal pulse indicative of the shortest possible measuring range to thereby utilize one of the predetermined measuring conditions during the duration period of the selected gate signal pulse.
Dependencies are inferred from the claim text.