Brother Kogyo Kabushiki-kaisha

Takesi Izaki

Kenji Sakakibara

Michitoshi Akao

Hiroshi Morisaki

Tokunori Katoh

Hiroto Sugahara

Satoshi Watanabe

Masanari Kobayashi

Shin Asai

An image forming apparatus has a thermal fixing unit which includes a heater to thermally fix an image on a recording medium. The temperature in the apparatus goes down when a replaceable unit is exchanged. A temperature sensor detects the reduction in temperature. A status sensor detects an exchanging state in which the replaceable unit is exchanged and outputs a detection signal indicating the exchanging state. A CPU judges that the heater is properly operating even if the temperature signal indicates the reduction in temperature when the detection signal is outputted.

Apparatus for detecting the proper functioning of a thermal fixing unit

Motor-control device for an image forming apparatus includes a motor, an encoder, a microcomputer, and a driving circuit. The encoder generates a pulse signal in response to rotation of the motor. The microcomputer includes a CPU, a RAM and a ROM. The CPU detects actual rotational speed of the motor based upon the pulse signal generated by the encoder. The CPU cyclically provides a driving signal by comparing the actual rotational speed with a predetermined target rotational speed of the motor. An operating cycle is proportional to a cycle of the pulse signal generated by the encoder. The driving circuit drives the motor based upon the driving signal provided by the CPU. The CPU determines the operating cycle based upon the predetermined target rotational speed. The CPU also determines whether the motor condition is normal or abnormal by comparing the driving signal with a predetermined reference driving signal.

Motor-control device for image forming apparatus

An image recording apparatus for recording an image of an original on a developer sheet with the use of a microcapsule, in which the developer sheet and the microcapsule sheet having a surface coated with immense number of photosensitive and pressure-rupturable microcapsules are subjected to pressure development by a pair of pressurizing rollers. To ensure that the pressure development is performed under the condition where the developer sheet and the microcapsule sheet are superposed one on the other, the nip and retract timings of the pressurizing rollers are determined properly according to the present invention. For example, the developer sheet is conveyed at a speed asynchronous with the microcapsule conveying speed and the conveyance of the developer sheet is stopped after its leading edge is introduced between the rollers held in spaced apart condition. The rollers are brought to the nip position to thereby start the pressure development when the exposure start line on the microcapsule sheet is in alignment with the leading end of the developer sheet. The retract timing is determined, for example, depending upon the size of the developer sheet.

Method and apparatus for performing pressure developement with a pair of

An image fixing device comprises a supporting platform for supporting thereon a recording sheet on which a provisional image is formed, one or more of rollers adapted to roll over the surface of the recording sheet in a direction substantially transversely of a paper feeding direction, and a resilient member for applying a downward force to the rollers to thereby apply pressure to the surface of said recording medium for fixing the provisional image under pressure. The rollers are connected to an arm rotating or swinging about a shaft extending vertically with respect to the platform. The swinging amplitude may be adjusted to become applicable to recording sheets of different width. The resilient member may be a coil spring coiled around the shaft in such manner as to apply a downward directing force to the rollers. Alternatively, the resilient member may be a shaft spring which comprises the rotating or swinging arm.

Image fixing device

A pressing device for pressing a sheet-shaped subject such as a recording sheet on which an image is formed by toners or an optical latent image is formed to be fixed or developed is disclosed. The disclosed pressing device comprises a pair of pressing rollers, between which the sheet-shaped subject is passed, one of the pressing rollers being arranged such that a rotary axis thereof crosses a feeding direction of the sheet-shaped subject at right angles while the other one of the pressing rollers being arranged such that a rotary axis thereof crosses the rotary axis of the one of the rollers at a certain angle; and means for supporting the other one of the rollers to be moved in the axial direction thereof when it is driven to rotate in contact with the one of the rollers being rotating.

Growing community of inventors

Nagoya, Japan

Takesi Izaki