Hitachi, Ltd.

Ricoh Company, Ltd.

Kyocera Corporation

Katsumasa Mikami

Masafumi Suzaki

Akira Sasaki

Tomoji Kitagishi

Yousuke Nagano

Akiyoshi Hakoyama

Shigetaka Furukawa

Fumio Takahagi

Ryooichi Kobayashi

Yoshihito Takahashi

Yasuo Nishiguchi

Tsuyoshi Yasutomi

Ryoichi Shiraishi

Takeo Honma

Kazuhiro Wakamatsu

Kenji Mori

Minoru Toyoda

Katsumi Kumada

Masaru Nakano

Yuichiro Suzuki

Kunio Tajima

Kouichi Oomori

Yoosuke Nagano

Rooichi Kobayashi

Yoshitaka Omori

A rotary member includes a rotating main body, and support members that are formed to be supported by bearings. Each of the support members includes a spindle core formed of a first metal, and a cylindrical sheath that sheathes a portion of the spindle core where slidably contacting respective one of the bearings and that is formed of a second metal different from the first metal.

Rotary member, developing device, and image forming apparatus

An electrophotographic apparatus comprising: a housing; a photosensitive member electrified by an electrification device; an exposure device for forming an electrostatic latent image onto the photosensitive member; a developing device for forming a toner image onto the photosensitive member; an intermediate transfer body to which the toner image is to be transferred; a transfer device for transferring the toner image formed on the intermediate transfer body onto a paper; a fixing device for heating the toner image on the paper; device for ejecting the paper outside the housing; device for exhausting the heat derived from the fixing device outside the housing; a cover provided on an upper portion of the fixing device; and an airflow path extending in a longitudinal direction of the fixing device and being provided by the cover and the housing, wherein the heat exhausting device is provided in an end portion of the airflow path.

Electrophotographic apparatus having heat exhaustion device

A combination of a thermal printer and an invertible ribbon cassette has a mechanism for preventing a portion of the inked ribbon extending between a supply core and a take-up core of the ribbon cassette from shifting in the direction perpendicular to the longitudinal direction of the inked ribbon with respect to a printing head. The mechanism includes a substantially planar surface of a platen, and a printing head is urged against the planar surface of the platen through the inked ribbon portion and a sheet to which solid ink in the area on the inked ribbon portion is transferred by the printing head. The width of that area on the inked ribbon portion in the widthwise direction of the inked ribbon is at most equal to a half of the width of the inked ribbon. Alternatively, the mechanism includes a detector mechanism operative in response to the variation in diameter of the inked ribbon wound on the supply core for applying a variable back tension in the reverse direction to the tension acting on the inked ribbon portion by the take-up core.

Thermal printer and invertible ribbon cassette therefor including a

The face pressure distribution shape of the graze portion of the thermal head is made to be consistent with the temperature distribution shape of the graze portion of the thermal head. The temperature distribution shape of the graze portion of the thermal head is made to be consistent with the face pressure distribution shape of the graze portion of the thermal head. The graze portion of the thermal head is formed projectingly in two steps, and the heating resistor element of the thermal head is provided on the top portion of the graze portion of the thermal head. A thermal transfer printer having no ink void and no ink transfer unevenness can be obtained.

Thermal transfer printer having an improved thermal head to improve ink

In a thermal printer having a flat platen, a flat platen support mechanism comprises a flat platen support plate, and a frame body. A projection having a curvature is provided between the flat platen support plate and the frame body. The projection having a curvature is to be swingable freely and to be movable with a slip movement. The projection is arranged on a center line of a flat platen width. When a thermal head is pressed with the flat platen, the flat platen swings smoothly. The thermal head is face contacted uniformly with the flat platen.

Thermal printer having a flat platen support mechanism

A thin film type thermal head includes a head substrate member, a partial projected glaze portion mounted on the head substrate member, a plurality of heating resistor elements provided on the partial projected glaze portion with each of the heating resistor elements having a uniform thin thickness and two electrode end portions. A common electrode is provided on the partial projected glaze portion and an individual control electrode is also provided on the partial projected glaze portion. The partial projected glaze portion has at least two projected portions of different height with the plurality of heating resistor elements having a portion thereof disposed on at least the highest projected portion of the partial projected glaze portion with both electrode end portions of each of the heating resistor elements being disposed on the partial projected glaze portion other than the highest projected portion of the partial projected glaze portion so as to enable a recording dot to become narrow in the printing direction.

Thermal head

A thermal head is pressed against a platen consisting of rubber through a recording paper or a heat sensitive paper. The thermal head is provided a head base, a glaze layer portion mounted on the head base, and a heating resistor portion provided on the glaze layer portion. An unit area surface pressure applied from the glaze layer portion of the thermal head to the recording paper or the heat sensitive paper is set to not less than 0.3 kg/mm.sup.2. A hardness of the rubber of the platen is adapted to about Hs 40.degree.-Hs 100.degree.. The high areas of the surface of the recording paper or the heat sensitive paper are flattened to increase the smoothness of the surface of the recording paper or the heat sensitive paper. A high quality printed product of the thermal transfer printer or the thermal printer can be obtained even when the relatively rough recording paper or the heat sensitive paper is used as the object paper.

Printer having a thermal head

A thermal transfer printer wherein the carriage is equipped with the ribbon cassette and the thermal head and has a take-up shaft engageable with the take-up core of the ribbon cassette, and clutch means is provided between the motion converting means and the take-up shaft of the carriage, rotational force is transmitted from said motion converting means to the clutch means, and the clutch means cuts off the transmission of the rotational force to the take-up shaft. The rubbing transfer phenomenon does not occur, since, the ink ribbon starts to travel before the thermal head contacts the platen or after the thermal head separates the platen. It is possible to effect control such that no rubbing transfer occurs even when the thermal head is pressed against the platen to effect printing while the carriage is moving transversely at high speed.

Thermal transfer printer

A thermal trasfer printer including a thermal head, and a platen positioned against the thermal head through a printing sheet. The thermal head has a substrate formed of heat insulating material, at least one glaze layer on a top surface of the substrate extending longitudinally thereof, a plurality of heat generating elements on the glaze layer, a plurality of electrodes each connected to the heat generating elements in a manner to form an opening for the heat generating elements and a protective layer for preventing the electrodes and heat generating elements from contacting the printing sheet to avoid their wear. A portion of the protective layer for protectng the heat generating elements has a height which is greater by more than 5 .mu.m than the height of a portion of the protective layer for protecting the electrodes. The width of the glaze layer transversely of the substrate is less than 200 .mu.m at a location which is 10 .mu.m below a top surface of the portion of the protective layer for protecting the heat generating elements in a vertical direction. The platen is a flat platen and its deflection caused to occur by a biasing force exerted on the thermal is more than 0.02 time and less than twice as great as the height of the glaze layer.

Thermal print head

In the thermal transfer printer for printing with an ink ribbon in plural columns, a center of a flat portion formed on the platen roller of a contact portion of the thermal head and a center of the thermal head are shifted corresponding to an amount of shift of printing position as against a center of width of the ink ribbon. When the printing position is set above as against the center of width of the ink ribbon, the center of the thermal head is set above width (P) of the flat portion being formed on the platen roller of the contact portion of the thermal head. When the printing position is set below as against the center of width of the ink ribbon, the center of the thermal head is set below width of the flat portion being formed on the platen roller of the contact portion of the thermal head. The present invention can prevent the shifting-up or the shifting-down of the ink ribbon at the thermal head in structure in which the center of the ink ribbon width and the center of the printing shift in the plural columns printing.

Growing community of inventors

Ibaraki, Japan

Katsumasa Mikami