Abstract: A unit retraction device has a hook member which engages with an engaged portion provided on a unit, and a retraction force generating mechanism which exerts a retraction force on the unit. The retraction force generating mechanism includes a first rotary member which is rotatably disposed on a first rotation pivot and to a rotating end part of which the hook member is coupled, a biasing member of which one end is hooked to the first rotary member and which biases the first rotary member in such a direction that the hook member retracts the unit into the apparatus body, and a second rotary member to which another end of the biasing member is hooked and which is rotatably disposed on a second rotation pivot. The second rotary member rotates in the same direction as the first rotary member as the latter is rotated by the biasing member.

Abstract: A sheet stacking device includes sheet stacking portion, electric motor, current detecting portion, abnormality determining portion, and updating portion. The sheet stacking portion is supported to be movable in up-down direction and configured to stack sheets thereon. The electric motor outputs, to the sheet stacking portion, a driving force for moving the sheet stacking portion in up-down direction. The current detecting portion detects a current value of the electric motor. The abnormality determining portion determines that the sheet stacking portion is in abnormal state when the detected current value is greater than a predetermined threshold. The updating portion updates the threshold based on the current value that was detected by the current detecting portion while the sheet stacking portion with a predetermined set amount of sheets stacked thereon was being moved by the driving force received from the electric motor.

Abstract: A unit retraction device has a hook member which engages with an engaged portion provided on a unit, and a retraction force generating mechanism which exerts a retraction force on the unit. The retraction force generating mechanism includes a first rotary member which is rotatably disposed on a first rotation pivot and to a rotating end part of which the hook member is coupled, a biasing member of which one end is hooked to the first rotary member and which biases the first rotary member in such a direction that the hook member retracts the unit into the apparatus body, and a second rotary member to which another end of the biasing member is hooked and which is rotatably disposed on a second rotation pivot. The second rotary member rotates in the same direction as the first rotary member as the latter is rotated by the biasing member.

Abstract: A copier includes a developing unit, a toner container, a first movable unit, and a second movable unit. The first movable unit carries the developing unit and is movable between a close position where a developing roller of the developing unit is located close to a photosensitive drum and a distant position where the developing roller is located away from the photosensitive drum. The second movable unit carries the toner container and is configured to drag the first movable unit from the close position to the distant position. The copier is configured so that while the second movable unit is located at a standby position for the drag, a clearance is formed between the first and second movable units to avoid physical contact between the first and second movable units.

Abstract: A sheet stacking device includes sheet stacking portion, electric motor, current detecting portion, abnormality determining portion, and updating portion. The sheet stacking portion is supported to be movable in up-down direction and configured to stack sheets thereon. The electric motor outputs, to the sheet stacking portion, a driving force for moving the sheet stacking portion in up-down direction. The current detecting portion detects a current value of the electric motor. The abnormality determining portion determines that the sheet stacking portion is in abnormal state when the detected current value is greater than a predetermined threshold. The updating portion updates the threshold based on the current value that was detected by the current detecting portion while the sheet stacking portion with a predetermined set amount of sheets stacked thereon was being moved by the driving force received from the electric motor.

Abstract: A copier includes a developing unit, a toner container, a first movable unit, and a second movable unit. The first movable unit carries the developing unit and is movable between a close position where a developing roller of the developing unit is located close to a photosensitive drum and a distant position where the developing roller is located away from the photosensitive drum. The second movable unit carries the toner container and is configured to drag the first movable unit from the close position to the distant position. The copier is configured so that while the second movable unit is located at a standby position for the drag, a clearance is formed between the first and second movable units to avoid physical contact between the first and second movable units.

Abstract: A transporting device moves sheet-like objects. The transporting device has an elevator plate mounted to be liftable and lowerable on a loading surface to load an object to be moved; a drive part to lift and to lower the elevator plate via gears; and a controller to execute a preparatory operation to operate the drive part in a direction only by a drive amount corresponding to the gear backlash during the time after the drive part has completed an elevator plate drive operation in one direction until the start of an elevator plate drive operation in another direction.

Abstract: A sheet feed tray has a bottom plate on which a sheet is to be placed; two side fences for positioning opposite widthwise sides of a sheet placed on the bottom plate; and an interlocking mechanism for interlocking movements of the side fences toward and away from each other. The interlocking mechanism includes two racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate. The pinion is rotatable about its central axis and is engageable with the pair of racks. Locking projections are disposed at the respective rack sides and project toward the bottom plate side. Contact portions are disposed at the bottom plate side and engage the locking projections with the pair of side fences maximally or minimally spaced apart from each other.

Abstract: A document conveying apparatus (1) includes a conveying unit (30) inside a document feeding section (10), and the conveying unit (30) includes two fans (34) for cooling the inside of the document conveying apparatus (1). The fans (34) are arranged to pass air from upstream to downstream with respect to the document conveying direction. Thus, the stream of air produced by the fan (34) flows along the document conveying direction so that a document sheet is conveyed without being affected by a braking effect. Moreover, the air stream produced by the fan (34) flows along the document conveying passage (13) both on the air intake side and the air exhaust side of the fan (34). This facilitates the conveying of a document sheet by pulling it on the air intake side of the fan (34) and pushing it on the air exhaust side of the fan (34).

Abstract: A transporting device moves sheet-like objects. The transporting device has an elevator plate mounted to be liftable and lowerable on a loading surface to load an object to be moved; a drive part to lift and to lower the elevator plate via gears; and a controller to execute a preparatory operation to operate the drive part in a direction only by a drive amount corresponding to the gear backlash during the time after the drive part has completed an elevator plate drive operation in one direction until the start of an elevator plate drive operation in another direction.

Abstract: A document conveying apparatus (1) includes a conveying unit (30) inside a document feeding section (10), and the conveying unit (30) includes two fans (34) for cooling the inside of the document conveying apparatus (1). The fans (34) are arranged to pass air from upstream to downstream with respect to the document conveying direction. Thus, the stream of air produced by the fan (34) flows along the document conveying direction so that a document sheet is conveyed without being affected by a braking effect. Moreover, the air stream produced by the fan (34) flows along the document conveying passage (13) both on the air intake side and the air exhaust side of the fan (34). This facilitates the conveying of a document sheet by pulling it on the air intake side of the fan (34) and pushing it on the air exhaust side of the fan (34).

Abstract: A sheet feed tray has a bottom plate on which a sheet is to be placed; two side fences for positioning opposite widthwise sides of a sheet placed on the bottom plate; and an interlocking mechanism for interlocking movements of the side fences toward and away from each other. The interlocking mechanism includes two racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate. The pinion is rotatable about its central axis and is engageable with the pair of racks. Locking projections are disposed at the respective rack sides and project toward the bottom plate side. Contact portions are disposed at the bottom plate side and engage the locking projections with the pair of side fences maximally or minimally spaced apart from each other.

Abstract: An image forming apparatus that includes an image reading section, a transportation path, a photoreceptor, transferring area, a fixing area, and a feeding speed controller. The feeding speed controller selects the speed at which an original document passes through the image reading section between two speeds. A first speed is used when the transfer sheet is normal sized and for a period of time prior to a large sized sheet entering the fixing area. Once a large sized sheet enters the fixing area, the feeding speed controller changes the speed of the original document from the first speed to the second speed to provide proper scaling of the reproduced image on the transferred sheet. The second speed may be adjusted depending on the type of transfer sheet being used to take into account the amount of stretching of the material used to make the transfer sheet.

Abstract: An image forming apparatus improved so that the leading end of a sheet can be exactly stopped in a nip position of registration rollers, and an image transferred to the sheet is not shifted. A locking device is provided in relation to the registration rollers provided in a conveying path. When the leading end of a cut sheet is inserted into the conveying path and is fed to the registration rollers, the registration rollers are brought into a state where it cannot be rotated by the locking device. Therefore, the leading end of the cut sheet fed is reliably stopped in the nip position of the registration rollers, and cannot enter the conveying path beyond this position. The conveyance of the cut sheet is thereafter resumed by the registration rollers and reaches a downstream pair of conveying rollers where the sheet is subjected to so-called secondary sheet feeding to an image forming section.

Abstract: An image forming apparatus which is adapted to transfer an image on a roll sheet fed out of a roll body and transported through a transportation path to an image forming section. When a user opens a front door of the image forming apparatus and sets a new roll body around a feed reel thereof, the leading edge of a roll sheet fed out of the roll body is located at a predetermined position in the transportation path. When the user closes the front door upon completion of replacement of the roll body, the roll sheet is further fed out, and a leading edge portion of the roll sheet having a predetermined length from the leading edge thereof is cut off. The cut-off portion is discharged through the transportation path out of a main body of the image forming apparatus in the same manner as in an ordinary sheet transportation process.

Abstract: An image recording apparatus according to the present invention has a photosensitive drum, a pre-transfer roller, and a fixing roller. The photosensitive drum, the pre-transfer roller and the fixing roller are generally rotated at an equal peripheral speed. Particularly, the peripheral speed of the photosensitive drum and the peripheral speed of the fixing roller are equal to each other, whereby there is no problem that an image transferred to a rolled-paper sheet from the photosensitive drum extends due to the leading end of the rolled-paper sheet being pulled after reaching the fixing roller. On the other hand, after the leading end of the rolled-paper sheet reaches the fixing roller, the peripheral speed of the pre-transfer roller is so controlled as to be lower than the peripheral speed of the photosensitive drum during a predetermined time period.

Abstract: An image forming apparatus having a structure in which it is judged whether or not the trailing end of a continuous sheet is fixed to a feeding reel. The continuous sheet wound around the feeding reel is pulled out, and is conveyed through a conveying path passing through an image forming section. When the continuous sheet is conveyed, the rotation or the stop of the feeding reel is detected. When the stop of the rotation of the feeding reel is detected while the continuous sheet is being conveyed, it is judged that the continuous sheet has been used up. The continuous sheet is further conveyed for a predetermined time period after the judgment. It is judged whether or not the trailing end of the continuous sheet is fixed to the feeding reel depending on whether or not the continuous sheet exists in a predetermined position of the conveying path.

Abstract: An image forming apparatus capable of cutting a strip-shaped continuous sheet on which an image is formed to a desirable cutting length. A rolled-sheet is conveyed by registration rollers and the like. The rolled-sheet is further led to the vicinity of a photosensitive drum through pre-transfer rollers. The rolled-sheet to which a toner image has been transferred is subjected to toner fixing processing by a fixing device. When the leading end of the rolled-sheet reaches the pre-transfer rollers, the rotational speed of a sheet feeding motor is increased during a predetermined time. Consequently, the sheet conveying speed on the upstream side of the pre-transfer rollers in a direction of sheet conveyance is increased, thereby forming slack in a sheet portion between the registration rollers and the pre-transfer rollers. Consequently, tension exerted on a sheet portion between the fixing device and the pre-transfer rollers does not affect the conveyance of the sheet by the registration rollers.

Abstract: An image forming apparatus capable of simplifying work for removing a sheet by a user after a jam occurs. An image is formed on a sheet having a predetermined length cut from a rolled-sheet. A cutting mechanism is provided in a halfway portion of a conveying path through which the sheet passes. When a jam occurs in the conveying path, the cutting mechanism is operated, whereby the sheet is cut. The sheet in the apparatus can be immediately removed, therefore.

Abstract: A roll sheet cutter mechanism for an image forming apparatus is provided which is adapted to cut a roll sheet 4 paid out of a feed reel 51 between a rotary blade 82 and a stationary blade 81. When the leading edge of the transported roll sheet 4 passes over the rotary blade 82 located at a guiding position, the rotary blade 82 guides the leading edge of the roll sheet 4 in a transportation direction. The rotary blade 82 returns to a cutting stand-by position before the tail edge portion of the roll sheet 4 passes over the rotary blade 82. Therefore, the occurrence of jam of the roll sheet due to the curling thereof can assuredly be prevented. Further, time loss can be eliminated because the rotary blade is adapted to return to the cutting stand-by position.