Abstract: An image forming apparatus which includes a fixing device including a fixing roller, a pressure roller pressed into contact with the fixing roller, and a thermistor in contact with a non-paper-passage region on the surface of the fixing roller, the fixing roller incorporating a first halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in a middle region thereof is higher than heat in opposite-end regions thereof, and a second halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in opposite-end regions thereof is higher than heat in a middle region thereof; and a controller for controlling power supply to the first and second halogen heaters. The controller starts power supply to the first and second halogen heaters to start warm-up of the fixing device, and cuts off power supply to the first halogen heater for a predetermined period of time during the warm-up.

Abstract: An image forming apparatus comprising: a fixing device including a fixing roller, a pressure roller pressed into contact with the fixing roller, and a thermistor in contact with a non-paper-passage region on the surface of the fixing roller, the fixing roller incorporating a first halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in a middle region thereof is higher than heat in opposite-end regions thereof, and a second halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in opposite-end regions thereof is higher than heat in a middle region thereof; and a controller for controlling power supply to the first and second halogen heaters. The controller starts power supply to the first and second halogen heaters to start warm-up of the fixing device, and cuts off power supply to the first halogen heater for a predetermined period of time during the warm-up.

Abstract: Umbilics of two surfaces are compared and it is determined from this comparison whether the suspect surface is a copy of the original surface based on the comparison. Comparing umbilics includes determining whether locations of the umbilics of the suspect surface match within a specified margin umbilics of the original surface, and determining whether pattern types of umbilics of the suspect surface match pattern types of corresponding umbilics of the original surface. A “weak” test may be performed, in which corresponding points on the two surfaces are compared, wherein the comparison of umbilics is performed if corresponding points of the two surfaces are located within a specified margin of each other. The points may be gridpoints on wireframes, which in turn may be based on lines of curvature of the surfaces. Comparing umbilics is performed if it is determined that each surface has at least one umbilic.

Abstract: The present invention relates to an optical scanning unit used for exposing a photosensitive drum of an image forming apparatus to light, and an image forming apparatus using this optical scanning unit. This optical scanning unit comprises a light source; an optical scanning mechanism for scanning with light from the light source; a start detecting mechanism for detecting scan light of the optical scanning mechanism at an end portion of a scanning range of the scan light to detect beginning of light scanning; and a frame which has a higher rigidity than that of a frame of an image forming apparatus and to which the light source, the optical scanning mechanism and the start detecting mechanism are attached.

Abstract: A printing apparatus includes a printing head for printing on a bank book, a platen disposed opposite the printing head, and a cam mechanism for moving the platen. A sensor detects the thickness of the bank book which is between the printing head and the platen, and a sensor moving mechanism moves the sensor toward or away from the platen. A controller controls the operation of the cam mechanism and the sensor moving mechanism as the sensor is moved to a measuring position approaching the printing head. The printing head is moved toward the platen according to a detected value and then the sensor is retracted from the measuring position. As a result, after moving the printing head, the sensor does not contact the surface of the bank book, and therefore does not produce jamming or oblique feeding of the bank book during a line feed or printing operation.

Abstract: There is disclosed an image forming apparatus which facilitates exchange of a process cartridge for forming an image and which can allow a large exchangeable process cartridge to be used.

Abstract: There is disclosed a process cartridge exchangeably provided to an image forming apparatus provided with an endless light-sensitive carrier, a mechanism for charging the light-sensitive carrier, a cleaner for cleaning residual toner on the light-sensitive carrier, a cartridge frame installed with at least the light-sensitive carrier, the charging mechanism and the cleaner, the cartridge frame having a fulcrum hole, and wherein a developing unit is detachably provided to the cartridge frame for developing an electrostatic image on the light-sensitive carrier, the developing unit including a developing unit frame having a free fit hole and connection rod freely fitted into the fulcrum hole and as well freely fitted to the free fit hole of the developing unit frame for installing the developing unit to the cartridge frame such that the developing unit is rotatably movable with respect to the cartridge frame.

Abstract: Disclosed are a single-side image forming device with a sheet inverting unit attached thereto for image forming on the reverse side of a sheet, and a double-side image forming apparatus that employs such a sheet inverting unit. The sheet inverting unit is detachable from an image forming apparatus, which has a sheet cassette; an image forming mechanism; a stacker; and a feeding path along which the sheet supplied from the sheet cassette is conveyed first to the image forming mechanism and then to the stacker. The sheet inverting unit comprises a switching lever for selectively guiding the image bearing sheet either toward the stacker or upward of the image forming device; switchback rollers for feeding the sheet guided upward by the switching lever and then inversely feeding the sheet; a guide path, which extends from the switchback rollers to a terminus in the vicinity of an inserting port of the image forming device; and feeding rollers provided along the guide path.

Abstract: The distance between a paper discharging portion and an intermediate tray in a paper discharging device is increased, thus increasing the quantity of papers stacked in the intermediate tray, and also allowing the easy correction of jamming and preventing curling downwardly and rearwardly of papers discharged from the paper discharging portion.

Abstract: A printer having a bail roller opening and closing apparatus including a bail roller for pressing a printing medium against a platen, a bail roller opening and closing mechanism for moving the bail roller between a closed position and an open position, and a clutch for connecting a space motor to the bail roller opening and closing mechanism. The bail roller opening and closing mechanism includes a rotating member rotationally driven by the space motor via the clutch, a transmission member causing the bail roller to be displaced by displacement of the transmission member and manual displacement of the bail roller, and a bidirectional motion transmission mechanism for transmitting bidirectional motion between the rotating member and the transmission member.

Abstract: A sheet feeding device is provided with a guide member for guiding sheets of paper sent out from the paper pile section in the sheet feeding direction, a feeding roller which is installed above the guide member and by which a sheet of paper is transferred in the sheet feeding direction, and a separation member which is engaged in non-contact with the feeding roller in the axial direction thereof and by which sheets of paper can be separated sheet by sheet between the separation member and the feeding roller and is so composed that a separation portion formed between the feeding roller and the separation member can be arranged in the downstream side in the sheet feeding direction from a minimum clearance portion formed between the guide member and the feeding roller.

Abstract: A printer having a bail roller opening and closing apparatus including a bail roller for pressing a printing medium against a platen, a bail roller opening and closing mechanism for moving the bail roller between a closed position and an open position, and a clutch for connecting a space motor to the bail roller opening and closing mechanism. The bail roller opening and closing mechanism includes a rotating member rotationally driven by the space motor via the clutch, a transmission member causing the bail roller to be displaced by displacement of the transmission member and manual displacement of the bail roller, and a bidirectional motion transmission mechanism for transmitting bidirectional motion between the rotating member and the transmission member.

Abstract: A printer having an ink ribbon shift apparatus includes a carrier unit having a printer head and a ribbon guide which is movable upwardly and downwardly. Up and down shift means are provided to shift an ink ribbon cassette up and down. A shaft is disposed parallel to a platen and extends along the entire range of movement of the carrier unit. The shaft shifts up and down together with the ink ribbon cassette and is engaged with the said ribbon guide. The up and down shift means moves the ink ribbon cassette up and down and the ribbon guide is thereby shifted up and down via the shaft so that a predetermined color band of an ink ribbon is positioned on a printing line.

Abstract: A printer comprises a cylindrical platen for supporting and feeding a printing sheet, a pinch roller in resilient contact with the platen to cooperate therewith to feed the cut sheet, and an inclined sheet guide on which a cut sheet is loaded. A leading edge of the cut sheet is inserted into a space between the platen and the pinch roller so that the cut sheet is ready to be compulsorily fed by the platen. When or after a cut sheet is loaded on the sheet guide, the platen is rotated in the reverse direction by a predetermined amount of rotation and then rotated in the forward direction to set the cut sheet at a given print start position. During the reverse rotation of the platen, the leading edge of the cut sheet is pushed up so that the posture of the cut sheet is corrected.

Abstract: A sheet feeding mechanism includes a receiving member, a feed member for feeding sheets from a stack thereof on the receiving member, and an overlapping feed preventing device including a roller to be rotated in a predetermined direction and a friction member cooperating with the roller. In relation to the friction member, a device is provided for substantially preventing the leading end of a fed sheet from contacting that part of the friction member which is upstream, in the sheet feeding direction, of the nipping site between the friction member and the roller.

Abstract: In a method and apparatus for changing the line of a sheet to be printed, the sheet is set in a print starting position, in which a front end of the sheet is located in front of bail rollers which feed the sheet together with a platen, and a carriage with a print head and a sheet guide is moved to a predetermined guide position in which the sheet guide is located at or near the center of width of the sheet, prior to every change of line, until the front end of the sheet is held between the bail rollers and the platen.

Abstract: Toner collecting apparatus in which a toner collecting container for collecting toner remaining on the surface of a photosensitive drum in a copying machine or a facsimile machine is provided, at the lower side thereof, with a toner receiving port, a sponge roller for rotatingly feeding collected tone disposed adjacent the toner receiving port, and an optical detector for detecting that a predetermined amount or more toner has been collected in the toner collecting container. The optical detector, is disposed on the toner collecting container. At least those portions of the toner collecting container located opposite to the optical detector are made of a light-permeable material.

Abstract: A fish breeding apparatus is disclosed, which comprises a frame body for the fish breeding framed by connecting rod elastic reinforcements to each other into a polygon at a side number of 4 to 30 through bent couplings, and a mooring cable connected at its one end to each of the bent couplings.

Abstract: An apparatus for developing a latent electrostatic image comprises a developer receptacle containing a developer composed of carrier particles and toner particles, a developer applying mechanism for holding on its surface a part of the developer in the developer receptacle and applying it to a latent electrostatic image to be developed, a toner receptacle containing toner particles, and a toner supplying mechanism to be selectively operated to supply toner particles to the developer in the developer receptacle from the toner receptacle. A detector detects the electrical conductivity of the developer in the developer receptacle.

Abstract: A multi-vane type compressor formed with vane back pressure spaces having introduced thereinto a suction gas pressure in the suction and compression strokes and a discharge gas pressure in the discharge stroke. The compressor includes supply grooves for introducing the discharge gas pressure into the vane back pressure spaces, which are each split into a trailing side portion and a leading side portion. Each leading side portion for coping with the terminating stage of the discharge stroke is exposed to the discharge gas pressure via a passageway offering large resistance to the flow of fluid, to throttle the gas forced out of the vane back pressure spaces as the vanes are forced into vane grooves to thereby raise the vane back pressure. This is conducive to prevention of the jumping action of the vanes, and wear of the tips of the vanes and to minimization of vibration and noise.