Mitsubishi Denki Kabushiki Kaisha

Keisuke Oda

Hiroshi Fukumoto

Kazuhiko Higashi

Kiyoshi Takakuwa

Kazuaki Arimoto

Terumi Kuwada

Kenichi Naruki

Fumio Kouzai

Yasunori Kasahara

Naoya Tanaka

Takashi Yoshida

A sheet feeding apparatus detects the position of a sheet (30) during feeding thereof and calculates a deviation of the detected sheet position relative to a reference position to thereby enable accurate color printing. A follower roller (41) for detecting a feeding amount of the sheet is in contact with the sheet which is fed by a sheet feeding roller 1, so that is rotated in accordance with the movement of the sheet. A sensor (43) generates an output signal each time the follower roller (41) rotates a predetermined angle of rotation. In one form of the invention, a timing deviation detector (51) is provided for detecting a deviation in the output timing of an output signal of the sensor relative to a reference value. In another form, a rotation angle deviation detector is provided for detecting a deviation in the rotation angle of the sheet feeding roller relative to a reference value each time the sensor generates an output signal. A feeding amount deviation calculator (52) periodically calculates a deviation in the amount of feeding of the sheet relative to a reference feeding amount based on the deviation in the output timing of the sensor output signal of based on the deviation in the rotation angle of the sheet feeding roller each time the follower roller rotates a predetermined rotation angle.

Sheet feeding apparatus

A thermal printer includes a memory for storing a correction for cancelling variations in a paper feed caused by a previously determined uneven paper feed, a first calculator for calculating an uneven paper feed in each of the lines to be printed, a second calculator for calculating a correction corresponding to the uneven paper feed calculated by the first calculator; and a control for controlling the paper feed in each of the lines according to the correction calculated by the second calculator.

Thermal printer with means for reducing color shifts

A printing paper protective device includes a protecting plate having a bent portion for separating a paper stack and an open portion for detecting when the paper stack has disappeared. The protecting plate is placed on the printing surface of printing paper and is accommodated in a paper cassette together with the paper stack.

Printing paper protecting device

A printer for printing variable density, multiple color prints in response to commands for controlling parameters, such as color density of a printed image, and image data sent from a host computer includes a CPU responsive to commands from the host computer; a first variable density regulating circuit storing color density correction data, receiving image data from the host computer, and connected to and controlled by the CPU for totally regulating the color density of a color image to be printed and outputting totally regulated image data; a second variable density regulating circuit connected to the first variable density regulating circuit and to the CPU and storing a plurality of predetermined density regulating data for finely regulating the color density of the color image to be printed in response to the totally regulated image data received from the first variable density regulating circuit and one of the predetermined density regulating data selected by an operator through the CPU and outputting finely regulated image data; and a printing device connected to the second variable density regulating circuit for receiving the finely regulated image data from the second variable density regulating circuit and printing the color image in response.

Printer with dual color density regulation

Growing community of inventors

Hiroshima, Japan

Keisuke Oda