Abstract: In a recording medium feeding apparatus for use in an electronic photography printing machine, an outer appearance of a popular paper feeding apparatus is formed to have the same outer appearance of an envelope feeding apparatus, thereby by exchanging the two feeding apparatuses the object to be recorded can exchange from the popular papers to the envelopes. The envelope feeding apparatus is formed to have the same height toward the right side and the left side of the envelopes when the envelopes are mounted and to make equal the force added to the right side and the left side. An envelope pressing member of the envelope feeding apparatus is constituted of a rod shape elastic member. A spring member supports the envelope pressing member as a fulcrum at one end portion of the envelope pressing member and opens or closes by the pressurized force and another end of the envelope pressing member is consistent with a tip end of the envelopes.

Abstract: A roller fixing unit for a color electrophotographic apparatus having a fixing roller and a pressing roller rotating in contact with each other, at least one of the rollers acting as a heating roller, as well as a control unit for connecting a power source to the heating device for only a predicted time duration based on a detected surface temperature of the heating roller so that the surface temperature of the heating roller reaches a setting temperature before the time when the top end of a first sheet of print medium having a color image arrives at the fixing roller in a case where the surface temperature of the heating roller in a standby state is lower than the setting temperature. The control unit is set to perform a power source connection for every sheet of print media coming out from an intermediate transfer unit in the color electrophotographic apparatus.

Abstract: An electrophotographic image fixing device having preventing offsetting and affording images of high quality is provided. The electrophotographic image fixing device has a heating roller 1, made up of a mandrel 5 and an elastic layer 4 of 40-60.degree. in hardness, as measured by a spring type hardness meter of JIS K6301, provided on the mandrel, and a pressure roller 2, arranged in contact with the heating roller 1 and having a surface layer 6 the hardness of which is equal to or higher than the hardness of the elastic layer 4 of the heating roller 1. A heater 8 is provided for heating and fusion-depositing a toner image onto a toner substrate 3, by passing through the nip portion between the two rollers the toner substrate 3 on which the toner image has been formed. The linear speed of the surface of the pressure roller is 1.005-1.05 times that of the surface of the heating roller.

Abstract: In an electrophotographic recording apparatus, toner images of different colors formed on a photosensitive belt are transferred in overlapping fashion to an intermediate transfer drum to form a color toner image and the color toner image is transferred to a secondary recording medium by means of a transfer unit and then fixed. The intermediate transfer drum includes an electrically conductive drum substrate and a dielectric layer whose resistance is adjusted to a predetermined range, and the drum substrate is connected to earth potential so that setting of an electric field for toner image transfer from the photosensitive belt may not interfere with setting of an electric field for toner image transfer by the transfer unit. Efficiencies of transfer at the two transfer sections can be improved to provide a color image of high quality and the apparatus can be reduced in size.

Abstract: Guide rollers are provided to be symmetric with respect to a center of the thermal head. The guide rollers comprise first two guide rollers provided in a vicinity of the thermal head, a guide roller provided in a vicinity of the supply core, a guide roller provided in a vicinity of the take-up core, and second two guide rollers. The second two guide rollers are disposed nearly in a vicinity of the first two guide rollers. The back tension force adding members comprise a fixed brake adding member provided at the supply shaft and an outer peripheral brake adding member for contacting the ink ribbon. The ink ribbon shifting down phenomenon can be prevented. The dirty background and the rubbing transfer phenomenon can be reduced. The aligned winding of the ink ribbon make possible a practical reciprocating ink ribbon cassette. without concern about ink ribbon winding accidents.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.