Oki Data Corporation

Oki Electric Industry Co., Ltd.

Naoki Sunaga

Masahiro Fukuda

Tatsuya Murakami

Masato Sakai

Shigeki Nakajima

Tsutomu Yamamoto

Takao Uchida

Takashi Wakana

Toyokazu Shiraishi

Kiyoshi Matsuda

Tetsuji Kojima

Koji Morimoto

Shigemi Hagiwara

Sumio Aramata

Shuuichi Fujikura

Hiromi Miyashita

To improve image quality upon preventing abrasion traces from strongly forming on a surface of a fusing member, an invented fusing device has a pressure member, a fusing member movably arranged as faced with the pressure member, and a contact element arranged in contact with an outer circumferential surface of the fusing member, with the surface roughness of the fusing member of 1.0 to 4.0 [&#x3bc;m]. When the fusing member is moved in contact with the contact element, the contact element rubs a surface of the fusing member, but in the fusing member, the portion in contact with the contact element and the portion not in contact with the contact element become about equal in the surface roughness with the above surface roughness.

Fusing device with rough surface and method for manufacturing the fusing member

A medium thickness detecting apparatus detects the thickness of a recording medium. A displacement section is disposed in a transport path through which a recording medium passes. When the recording medium passes the displacement section, the displacement section displaces in a direction substantially normal to the surface of a recording medium. An amplifying section amplifies a displacement of the displacement section by a predetermined factor. A thickness determining section outputs a signal representative of an amplified value of the displacement. The displacement section may be one of two rollers between which the recording medium passes, and displaces upward when the recording medium passes between the two rollers. Alternatively, the displacement section my be positioned to sit on a stage provided in the transport path such that the displacement section is pushed away from the stage when the recording medium passes between the displacement section and the surface.

Medium thickness detecting apparatus

An electrophotographic image recording apparatus incorporates a fixing unit in which a toner image deposited on a print medium is fused by heat under pressure. The fixing unit includes a fixing member and a separator plate. The fixing member is in pressure contact with a pressure member. The separator plate that is disposed close to the fixing member and has a longitudinal portion extending in a direction transverse to a transport path of the print medium. The separator plate has a mid portion of the longitudinal portion. The mid portion has resiliency to extend away from the transport path and a guide member that pushes the mid portion of the separator plate to maintain the entire longitudinal portion flat so that mid portion is prevented from extending away from the transport path.

Fixing unit having a separator plate for separating a print medium from a roller

When the surface temperature of a heating roller exceeds a predetermined temperature, bearings that rotatably support the heating roller melt. Thus, a pressuring roller causes the heating roller to move toward a temperature detecting device. Thus, the heating roller comes in contact with the temperature detecting device. Consequently, when a defect takes place, the warm-up time after the temperature detecting device works until the power to the heater is shut off can be reduced. In addition or in the alternative, an electrode plate has edges electrically contacting and connecting the heater in the heating roller and a power supply. As the heating roller moves, electrical contact between the heater and the electrode plate is broken and the power from the power supply to the heater is disconnected. As a result, an electrophotographic printing apparatus can be prevented from getting defective, thereby improving the reliability thereof.

Overheating prevention device for a fixing unit

Printer provided with an image reading unit

Growing community of inventors

Tokyo, Japan

Naoki Sunaga