Abstract: A toner image that is formed on a photosensitive drum is transferred onto a paper and the paper is fed between a heat roller and a pressure roller so that the toner is fixed onto the paper. The guide plate for guiding the paper between the heat roller and the pressure roller is arranged so as to contact the paper between a first surface and a second surface. Because the position of the paper is fed stably, the toner is not scattered from the paper and deterioration in the image is prevented.

Abstract: Each rear edge of an upper plate that receives a portion of a front edge side of a sheet is engaged with each slit provided to a sheet support member that receives a portion of a rear edge side of the sheet. Further, an end guide where the rear edge of the sheet contact is provided to the sheet support member. Therefore, the end guide moves back and forth in synchronization with a vertical swing of the upper plate. Even though the upper plate is vertically swung, a distance between a front edge of the upper plate and the end guide is maintained at substantially the same distance. Consequently, a deviation of the sheet caused by swinging only the upper plate can be prevented.

Abstract: In a thermal fixing device, a thermister, a temperature fuse and a thermostat are disposed in alignment with symmetrical positions spaced by a predetermined distance from the axial center of a heat roller, that is, a temperature distribution center of a heater. Accordingly, the temperature fuse and the thermostat can sense substantially the same temperature as that sensed by the thermister, and the temperature fuse and the thermistate function as thermal cutoff devices promptly and properly to prevent the heat roller from overheating when the heat roller is excessively heated.

Abstract: A sheet accommodating device is provided which always performs stable sheet feeding in accordance with sizes of sheets or the number of sheets to be stacked. A holder member that is movable back and forth supports a sheet pressing plate near the center of gravity of the sheets. The holder member is movable in accordance with the sizes of the sheets or the amount of stacked sheets, so that the sheets can be stacked and fed with stability.

Abstract: A heat-resistant insulation sheet 40 is formed from an insulation base 41 divided into an insulation region Z, a heat-generating region Y, and a pressing region X. The insulation base 41 is formed from a polyimide resin film member. A rectangular-shaped electrically-conductive resilient body 46 is attached on the pressing region X and a resistance-type heat-generating body 44 is attached on the heat-generating region Y. The resilient body 46 and the heat-generating body 44 are formed integrally from the same stainless steel plate, which is attached on the surface of the insulation base 41 and etched into a desired pattern. The heat-resistant insulation sheet 40 formed in this manner is mounted into a roller body in a rolled up condition with the pressing region X disposed interior to the heat-generating region Y, and the heat-generating region Y disposed interior to the insulation region Z.

Abstract: A collector plate 74a, which serves as a contact surface of a rotational electrode member 71, is disposed to intersect an imaginary rotational axis RA of a thermal roller 10. The stationary electrode member 72 can be brought into contact with the collector plate 74a at a position near the rotational center of the collector plate 74a. As a result, friction between the two electrode members can be suppressed so that the electrode members do not wear out as quickly. Defective contact or damage of electrode members can be reduced.

Abstract: A fixing apparatus comprises a fixing heating roller for heating a recording medium deposited with a recording material, and a pressing roller for transporting the recording medium while interposing it between the fixing heating roller and the pressing roller. The heating roller includes a hollow main roller body, and a sheet-shaped insulative film provided over an inner circumferential surface of the main roller body. A pattern of a resistance heat-generating element and an electrode pattern connected to the pattern of the resistance heat-generating element are formed on the insulative film. A margin is provided between the electrode pattern and at least one of edges of the insulative film in the circumferential direction, and the margin has a size which is not less than a distance that conforms to the UL1950 standard with respect to a voltage supplied to the resistance heat-generating element. Thus, the insulation performance between the electrode pattern and the main roller body is ensured.

Abstract: Even if a halogen lamp is thermally expanded or contracted when electricity is supplied to it, the fixing unit in accordance with the invention responds to the thermal expansion or contraction of the halogen lamp without breaking it and supplies electricity to the halogen lamp reliably. In the fixing unit, lead pins extend from both ends of the halogen lamp that is disposed in a heating roller. Each lead pin is fixed at a pin fixing portion wherein each lead pin is pinched by a top pinching portion and a bottom pinching portion of one of a pair of conductive spring members. A static friction force generated between each conductive spring member and the corresponding lead pin is set to not exceed 10 kgf, and the surface roughness of each lead pin is adjusted to not exceed Rz 3.2 .mu.m. A cone-like pin guide portion which is open at the lead pin side is formed on the top pinching portion of the conductive spring member.

Abstract: Wear of the surface of a heating roller caused by toner, paper powder and other like contaminants and a cleaning force are made uniform over a length of a heating roller by setting the press-contact force of a cleaning member with respect to each end portion of the heating roller smaller than the press-contact force at a portion other than the end portions on the basis of a tendency for the distribution of the toner, paper powder and the other like contaminants resulting from the rotation of the heating roller. Five attaching holes are formed at an upstream portion of a lower cover, defining the bottom of a fixing chamber in a fixing unit, lock members are not fitted into the two attaching holes corresponding to the end portions of the heating roller. Lock members are fitted into the other three attaching holes corresponding to the central portion of the heating roller in a state where a base end portion of the elastic spring member is inserted into the three attaching holes.

Abstract: Curl caused in a paper sheet in a fixing device during fixing of a toner image is removed while smoothly changing a direction of feed of the paper toward a plurality of paired discharge rollers in the fixing device. Anti-curl ribs, each having a rounded face that projects to pass through a plane connecting a contact point between a heating roller and a pressing roller and a contact point between the respective discharge rollers are arranged between the heating roller and the pressing roller and the plurality of paired discharge rollers in a fixing unit. Further, a first set of paired discharge rollers and a fourth set of paired discharge rollers are arranged respectively in correspondence with the anti-curl ribs and two of the anti-curl ribs are provided in correspondence with the side portions of the paper. Lastly, bent guide films are arranged on both sides of second guide ribs that correspond to the first and fourth sets of paired discharge rollers to facilitate paper feed.

Abstract: A fixing device having a heat roller and a pressure roller in nipping relation therewith. The heat roller includes a metallic sleeve member and a halogen lamp disposed in a hollow space of the sleeve member. The pressure roller includes a core member and an elastic rubber layer formed over the core member. The sleeve member provides a moment of inertia of area ranging from 700 mm.sup.4 to 1700 mm.sup.4 and a maximum deflection amount of not more than 0.29 at the longitudinal center. Further, the sleeve member provides a thermal capacity of not more than 0.035 J/K.

Abstract: The invention provides a fixing device in which a temperature fuse melts quickly when a heat roller becomes overheated. The heat roller, to which pressure is applied by a pressure roller placed in a fixing unit case, is axially supported by bearings which are made of synthetic resin and soften upon overheating of the heat roller. An electrical insulating cover, placed adjacent the heat roller opposite to the position of the pressure roller is fixed to an inner surface of a lower case. The electrical insulating cover has a heat collecting surface which is arcuate in cross section and placed opposed to a circumferential surface of the heat roller. The temperature fuse is fixed to the reverse side of the cover and is connected in series with an electric circuit from a power source to a halogen lamp in the heat roller.

Abstract: A sheet-supply unit including a drive source for supplying rotational drive power; a supply roller supplying one sheet at a time to a sheet transport pathway when rotated; a partial gear provided so as to rotate integrally with the supply roller and be capable of receiving transmission of rotational drive power from the drive source; a lever pivotable between a transmission mode wherein rotational drive power from the drive source is transmitted to the partial gear and a non-transmission mode wherein rotational drive power from the drive source is prevented from being transmitted to the partial gear; a pair of resist rollers disposed in the sheet transport pathway for stopping and aligning a sheet supplied by the supply roller and for transporting the aligned sheet, and capable of receiving rotation drive power from the drive source; an actuator capable of switching between a first mode and a second mode; and a switching mechanism for, based on the mode of the actuator, pivoting the lever into the transmissio

Abstract: A fixing device includes a heat roller, which is rotatably mounted to a frame, a press roller, which is rotatably mounted to the frame, and a press mechanism for pressing the press roller against the heat roller. The press mechanism has a displacement member that is displaceable in a press direction, a bearing portion that is movable in the opposite direction relative to the displacement member and supports the press roller at a shaft portion thereof, an urging member for urging the bearing portion in the press direction, and displacing structure for displacing the displacement member between a first position corresponding to a non-press position and a second position corresponding to a press position. The urging force of the urging member in the press direction is reinforced by action of the bearing portion, which is displaced in the opposite direction relative to the displacement member when the displacement member is displaced from the first position to the second position.

Abstract: An image recording apparatus for recording an image on an image receiving sheet with use of a photosensitive microcapsule sheet on which microcapsules being photohardenable upon exposure and being hardened by heating are applied, is disclosed.The image recording apparatus comprises an exposing means for rendering the microcapsules hardenable upon exposure thereby, a heating means for forming a latent image on the photosensitive sheet by heating the exposed hardenable microcapsules, a feeding means for feeding the photosensitive sheet to the image receiving sheet through a feeding path and a pressure means for transferring the latent image on the image receiving sheet by pressurizing both photosensitive sheet and the image receiving sheet in superposing the sheets.In such the image recording apparatus, the feeding means is located downstream the heating means on the feeding path.

Abstract: An image recording apparatus having a sheet cartridge in which a rolled photosensitive recording medium is accommodated. The sheet cartridge has a sheet retaining device for preventing the recording medium from being retracted into a cartridge casing. The retaining device also provides a light shielding member. The image recording apparatus also includes structure for preventing the cartridge from being removed in a case where a residual recording medium is still rolled in the cartridge casing. The image recording apparatus is provided with a wiper member for removing dusts deposited on a surface of a feed roller. Further, a sensor element is provided for detecting non-rotation of a takeup shaft or a slack of the recording medium.

Abstract: An image recording apparatus which produces an image on a photosensitive recoding medium through a light shieldable mask image carried on a light transmissive member. The apparatus comprises; a mask image forming means provided at a mask image forming zone for forming the light shieldable mask on the light transmissive member; exposure means for exposing the photosensitive recording medium to light through the light transmissive member carrying the mask in an exposure zone for forming a latent image corresponding to the mask image on the photosensitive recording medium, the mask image forming zone being identical with the exposure zone; developing means for developing the latent image into a visible image on the photosensitive recording medium; and, a holding means for selectively holding portions of the light transmissive member extending outside of the exposure zone and maintaining the light transmissive member in the exposure zone during the mask image formation and during the exposure.