Tohoku Ricoh Co., Ltd.

Ricoh Company, Ltd.

Takayuki Onodera

Hideki Asai

Kazuyoshi Kobayashi

Atsushi Ashikagaya

Kohki Ohmura

Toshimitsu Okubo

Yukihiko Yoshino

Yoshinobu Sai

Nobuyuki Hoshi

Toshiaki Sannohe

Sigenobu Irokawa

Takuo Satoh

Masayuki Abe

Yasuo Endoh

A sheet feeding device capable of again feeding, when failed to feed a sheet, the sheet by retry control is disclosed. The sheet feeding device includes a sheet tray loaded with a stack of sheets and a feed roller for sequentially feeding the sheets from the sheet tray one by one. A leading edge sensor is positioned downstream of the feed roller in the direction of sheet feed for sensing the leading edge of the sheet fed from the sheet tray. A registration roller pair is positioned downstream of the leading edge sensor in the direction of sheet feed for conveying the sheet toward an image transfer station at a preselected timing. When the retry control is to be executed, control means varies the content of control in accordance with information output from the leading edge sensor.

Sheet feeding device and printer including the same

A sheet feeding device for a printer, e.g., a stencil printer including an ink drum with a master wrapped therearound and a press drum one of which is pressed against the other during printing is disclosed. The sheet feeding device is capable of feeding a sheet at a preselected speed without regard to a print speed varying every moment due to various factors particular to an ink drum driveline, i.e., whether a set print speed is higher than a standard print speed or lower than the same. This successfully obviates the short loop of a sheet which would result in a skew or a feed failure. In addition, the device reduces noise at print speeds lower than the standard print speed and used more often than the other print speeds.

Sheet feeding device for a printer

A stencil printer or similar printer and an ink viscosity sensing device therefor are disclosed. The viscosity of ink which is the root cause of the degradation of image equality ascribable to, e.g., temperature and down time is directly sensed. The viscosity is combined with other information including a set print speed and the kind of the ink in order to effect delicate print pressure control matching the actual conditions of the printer. Stable image quality with a minimum of fluctuation is achievable against the varying environment and without resorting to complicated control pattern tables or a number of sensors.

Stencil printer and ink viscosity sensing device

An offset printer having a printing section and a plate making section in a unitary assembly. The plate making section is located above the printing section. The printing section includes a plate drum, a rubber drum, and a press drum. The press drum is disposed above and at a predetermined angle relative to the rubber drum. The diameter of the press drum is at least two times as great as the diameter of the rubber drum.

Offset printer having a press drum larger than its rubber drum

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Miyagi, Japan

Takayuki Onodera