Fujitsu Corporation

Masato Ishii

Hirohiko Kubo

Masanori Tokuhisa

Ryoichi Iwama

Syuzou Masuda

An electrophotographic printing machine includes a transporting part for transporting a recording medium, and a carriage movable in a first direction transverse to a second direction in which the recording medium is transported. The carriage includes a process part for forming a latent image on an image carrier and forming a toner image of the latent image, and a fixing part for thermally fixing a transferred image corresponding to the toner image on the recording medium. A transfer part, which is provided at a first side of the recording medium opposite to a second side thereof at which the carriage is located, transfers the toner image on the recording medium to thereby form the transferred image. A refuge part in which the fixing part can take refuge is located at a side of the transfer part and located in a print starting position in which the fixing part provided in the carriage is located so as to prevent the transfer part from being thermally affected by the fixing part.

Electrophotographic printing machine having a heat protecting device for

A xerographic serial printer includes a sheet feeding mechanism for feeding a recording sheet, a xerographic recording head for recording a toner image on a recording sheet, a carriage disposed below a sheet path for carrying the xerographic recording head such that the xerographic recording head records the image on a lower major surface of the recording sheet, a carriage actuation mechanism for driving the carriage along a recording sheet in a horizontal direction such that the xerographic recording head scans the lower major surface in the horizontal direction, a platen plate disposed above the recording sheet feed path in engagement with an upper major surface of the recording sheet, for causing a transfer of the toner image to the lower major surface of the recording sheet, and a fixing unit for fixing the toner image transferred to the lower major surface of the recording sheet by heating the toner image on the recording sheet.

Xerographic serial printer with carriage below the paper path

A toner quantity detecting system has a toner quantity detector (4c) and is capable of accurately detecting the decrease of the quantity of toner contained in the toner container of the developing unit of an image recording apparatus to an upper threshold quantity and to a lower threshold quantity regardless of the inherent output characteristic of the toner quantity detector (4c) and determining a prewarning voltage (E.sub.nep) representing the upper threshold quantity and a warning voltage (E.sub.emp) representing the lower threshold quantity so that the difference between the prewarning voltage (E.sub.nep) and the warning voltage (E.sub.emp) is sufficiently large. The prewarning voltage (E.sub.nep) and the warning voltage (E.sub.emp) are determined on the basis of the inherent output characteristic of the toner quantity detector (4c). The output voltage (E.sub.s) of the toner quantity detector (4c) is compared with the prewarning voltage (E.sub.nep) and the warning voltage (E.sub.emp) to provide a prewarning signal (NAL) upon the reduction of the quantity of the toner to the upper threshold quantity and to provide a warning signal (EAL) upon the reduction of the quantity of the toner to the lower threshold quantity.

Toner quantity detecting system for an image recording apparatus, a

An electrophotographic recording apparatus including a light-sensitive drum for carrying toner images developed thereon, and a transfer unit arranged at a prescribed distance from the light-sensitive drum for transferring the toner images from a light-sensitive drum to the image recording paper. The transfer unit has a charging wire electrode for electrically charging the paper and a generally inverted U-shaped housing having spaced sidewalls with respective bottom edges. A separator is provided for separating the paper from the light-sensitive drum as the paper travels along a conveying path and comprises a paper separating plate extending from the downstream one of the bottom edges of the housing of the transfer unit in the downstream direction of the travel of the paper along the conveying path side thereof, with and the housing of the transfer unit is grounded. The paper separating plate has a distal end having a saw tooth shape along the length thereof, as measured transversely to the conveying path.

Means for separating image recording medium in electrophotographic

An image forming apparatus includes a developing unit and a photoconductive drum. A toner sensor is disposed in a toner mixing chamber of the developing unit. A mixing member is included in the chamber for mixing and frictionally charging the toner. A detection device is mounted on the unit for detecting the residual quantity of density of the toner according to the output voltage of the sensor. The residual quantity or density of the toner is detected by sampling an output voltage of the toner sensor at predetermined times during a predetermined period while the mixing member is rotated at a specific constant speed, and averaging the sampled vales. As a result correct data for the residual quantity or density of the toner can be obtained.

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Kawasaki, Japan

Masato Ishii