Ricoh Company, Ltd.

Shoji Yanagida

Hideto Miyazaki

Takashi Kimura

Takeshi Motohashi

Shunichi Ogawa

Mamoru Takezawa

Shingo Kato

Tomoyuki Moriya

Makoto Yumoto

Osamu Kuramochi

Eiji Hashimoto

A printing device such as a printer of the type using a type wheel in which a carriage is loaded with a printing mechanism and movable along a carrier to allow the printing mechanism to print out data on a paper, which is wrapped around a platen. The carrier and/or the carriage is produced by press-forming a single sheet metal to cut down the production cost and the number of structural elements of the printer.

Printing device with carriage and carrier therefor each integrally

An electromagnet driving circuit particularly suited for use in impact printers as a means for driving to move a printing hammer includes a current control circuit for controlling a driving current to be applied to an electromagnet. In one aspect of the invention, a feed back circuit is provided between a voltage source and the current control circuit so as to compensate for fluctuations at the voltage source. In another aspect of the invention, the current control circuit is structured to use a temperature-dependent reference voltage in determining the level of the driving current thereby allowing to carry out a temperature-compensated operation.

Electromagnet driving circuit

Herein disclosed is a drive system for a servomotor for use with the carriage of a serial printer, comprising a source of a variable command signal representative of the speed at which the servomotor is to operate, detecting means for detecting the output speed of the servomotor and producing a signal representative of the detected servomotor output speed, and first and second voltage sources respectively operative to supply predetermined voltages, the voltage from the first voltage source being higher than the voltage from the second voltage source. The drive system further comprises switching means responsive to the detected speed signal and operative to select the first voltage source when the detected speed signal is increased in voltage to a first threshold level and select the second voltage source when the detected speed signal is decreased in voltage to a second threshold level lower than the first threshold level, and drive means responsive to the command signal and operative to provide a path of current from the voltage source selected by the switching means to the servomotor.

Servomotor drive system

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Yokohama, Japan

Shoji Yanagida