Electronic weighing apparatus

Abstract

An electronic weighing apparatus, comprising a scale mechanism having a weighing plate for placing an article being weighed, a movable slit plate associated with the weight of said article on said weighing plate and having a series of slits equally spaced in the moving direction, a light source provided at one side of said slit plate, a photodetector provided at the other side of said slit plate opposite to said light source, whereby a pulse train is generated from said photodetector. The number of pulses in the pulse train is associated with the movement of the slit plate and thus with the weight of said article. A counter for counting the number of pulses of said pulse train for providing a weight value signal, a display register for storing the weight value signal, and a display responsive to the register for displaying the weight value in said register are employed. An addition/subtraction detecting circuit is provided for generating an addition pulse or a subtraction pulse and a minus sign signal responsive to an incremental or decremental change of said pulse train. A vibration detecting circuit is provided for detecting a sequential occurrence of an incremental pulse and a decremental pulse in the order described, and said display register is adapted to be prevented from being loaded with a new weight value signal in the counter for a predetermined time period in response to the output from said vibration detecting circuit, whereby the previous data is displayed in the display for said predetermined time period, with the result that flickering of the display is eliminated.