Importance

Loading Importance Indicators...

Abstract

A serial dot matrix printer is provided with a slit encoder and an optical sensor opposed to the slit encoder. In the slit encoder, firing signal slits each having a fixed width are provided at a fixed pitch, and block signal slits each having a width smaller than that of each firing signal slit are provided in every block composed of a plurality of the firing signal slits. As a carriage moves, the optical sensor moves along the slit encoder to produce a signal at every slit. The signal from the optical sensor is applied to a first control device having a block detector and a firing timing unit. The block detector receives the signal from the optical sensor, measures the passing time between every slit, and detects a block signal according to a difference in passing time between the slits. The firing timing unit produces firing timing signals obtained by equally dividing the passing time of each of the firing signal slits by a predetermined number whenever the passing time of the each firing signal slit is measured. There is further provided a second control device having a carriage controller for controlling a carriage moving motor according to the block signal.

Loading the Abstract Image...

First Claim