Abstract: There is provided a sheet feeding device in which a sheet is discriminated at preliminary loosening before feeding, and is set to be controlled according to the type of the sheet by a simple configuration without requiring a special configuration. In the sheet feeding device in which air is blown onto a sheet stack, and a sheet floating at the uppermost level by the blowing is absorbed and conveyed, a sheet type is discriminated, based on a moving amount of the tray, at preliminary loosening before sheet feeding after setting the sheet in a tray.

Abstract: There is provided a sheet feeding device in which a sheet is discriminated at preliminary loosening before feeding, and is set to be controlled according to the type of the sheet by a simple configuration without requiring a special configuration. In the sheet feeding device in which air is blown onto a sheet stack, and a sheet floating at the uppermost level by the blowing is absorbed and conveyed, a sheet type is discriminated, based on a moving amount of the tray, at preliminary loosening before sheet feeding after setting the sheet in a tray.

Abstract: An image forming system which is capable of preventing paper jam from occurring in a sheet processing apparatus to thereby maintain the stability of the system. An alignment plates of an alignment unit movable in a lateral direction each sheet are brought into abutment with opposite side edges of sheets stacked on the sheet stack unit to laterally align the sheets. A lateral registration sensor unit detects a lateral position of the sheet being conveyed. When the detected lateral position of the sheet is beyond a predetermined position, the CPU of the apparatus changes the standby positions of the alignment plates such that spacing therebetween in the lateral direction the sheet is widened by a predetermined amount, and extends the conveying interval of sheets in the image forming apparatus by a predetermined time period.

Abstract: A sheet stacking apparatus which is capable of efficiently stacking sheets of various sizes while making efficient use of space therein to realizing compactness of the apparatus. Stacker trays that are driven by respective tray lift motors perform a lifting/lowering operation to have sheets stacked thereon. Selection is made according to the size of sheets between a first stacking mode for stacking sheets having a size not larger than a predetermined size on one of the stacker trays and a second stacking mode for stacking sheets having a size larger than the predetermined size in a state extending on the stacker trays. When it is determined that one of the stacker trays is faulty, execution of the second stacking mode is inhibited, and execution of the first stacking mode using the other stacker tray is permitted.

Abstract: A sheet processing apparatus capable of reliably superposing a sheet to be buffered and a following sheet in a manner displaced by an allowable displacement amount, thereby making it possible to suppress generation of misalignment. A sheet discharged from an image forming apparatus is temporarily held back, and a following sheet is superposed on the held-back sheet in a state displaced in a conveying direction. A length in the conveying direction of the sheet to be held back and a length in the conveying direction of a sheet bundle of the superposed sheets are measured. A displacement amount provided between the superposed sheets, computed as a difference between the measured length of the sheet and the measured length of the sheet bundle, is adjusted such that the displacement amount becomes a target displacement amount.

Abstract: A drive signal for driving a semiconductor laser is generated on the basis of an image signal inputted in synchronism with a pixel clock. A bias signal to the semiconductor laser is generated at a timing earlier than the drive signal by a predetermined time. The bias signal is disabled in synchronism with the leading edge of the drive signal.

Abstract: A linear motor for giving thrust to a movable unit capable of linearly moving freely in one direction with respect to a stator, comprising a plurality of permanent magnets arranged on the base side by lining up a positive pole and a negative pole in the one direction; and a plurality of flat shaped coils arranged along the arrangement direction of permanent magnets and fixed as armatures to said movable unit side so as to face the permanent magnets by leaving an electromagnetic gap; wherein a coil fixed surface on the stage side is provided a recessed portion for defining an air gap between the coil fixed surface and said coils.

Abstract: An image forming system which is capable of preventing paper jam from occurring in a sheet processing apparatus to thereby maintain the stability of the system. An alignment plates of an alignment unit movable in a lateral direction each sheet are brought into abutment with opposite side edges of sheets stacked on the sheet stack unit to laterally align the sheets. A lateral registration sensor unit detects a lateral position of the sheet being conveyed. When the detected lateral position of the sheet is beyond a predetermined position, the CPU of the apparatus changes the standby positions of the alignment plates such that spacing therebetween in the lateral direction the sheet is widened by a predetermined amount, and extends the conveying interval of sheets in the image forming apparatus by a predetermined time period.

Abstract: A sheet processing apparatus which is capable of accurately superimposing or aligning sheets discharged from an image forming apparatus during buffering even when the space intervals between the sheets are reduced. A sheet processing apparatus sequentially receives sheets discharged from an image forming apparatus and carries out post-processing on the sheets. During execution of the post-processing on the sheets, a plurality of sheets are discharged successively from the image forming apparatus and superimposed one upon another around a buffer roller. The conveying speed of the sheets is controlled such that a conveying time period over which a sheet preceding a final one of the sheets to be superimposed one upon another around the buffer roller is conveyed over a predetermined path section is shorter than a conveying time period over which the final one is conveyed over the predetermined path section.

Abstract: An image forming system which is capable of preventing paper jam from occurring in a sheet processing apparatus to thereby maintain the stability of the system. An alignment plates of an alignment unit movable in a lateral direction each sheet are brought into abutment with opposite side edges of sheets stacked on the sheet stack unit to laterally align the sheets. A lateral registration sensor unit detects a lateral position of the sheet being conveyed. When the detected lateral position of the sheet is beyond a predetermined position, the CPU of the apparatus changes the standby positions of the alignment plates such that spacing therebetween in the lateral direction the sheet is widened by a predetermined amount, and extends the conveying interval of sheets in the image forming apparatus by a predetermined time period.

Abstract: A sheet conveyance apparatus capable of detecting a sheet end portion in a short time period even if sheets are conveyed at a narrow interval and at high speed, thus making it possible to expedite the start timing of a subsequent sheet alignment operation. In accordance with results of detection by lateral registration detection sensors performed when a sheet reaches a lateral registration detection sensor unit, the sensor unit is moved in a width direction for sheet end detection. Based on a moving distance of the sensor unit from a standby position to a position where the sheet end is detected, a shift amount to be shifted the sheet in the width direction, i.e., a lateral registration error, is computed.

Abstract: Whether an image to be formed has a prescribed M×N pixel pattern is determined by a comparator. If it is determined that the image has the prescribed M×N pixel pattern, then a light-quantity correction signal that is for reducing the current that flows through a semiconductor laser is output to a laser driving circuit when the laser emits a laser beam of a pixel of interest contained in the M×N pixel pattern.

Abstract: A drive signal for driving a semiconductor laser is generated on the basis of an image signal inputted in synchronism with a pixel clock. A bias signal to the semiconductor laser is generated at a timing earlier than the drive signal by a predetermined time. The bias signal is disabled in synchronism with the leading edge of the drive signal.

Abstract: The invention comprises registration roller pairs which detect a skew amount of a sheet being conveyed; registration roller pairs which perform skew correction of the sheet while the sheet is being conveyed; a punch unit which performs punching of the sheet; a punch-unit driving portion which drives the punch unit; a sheet-edge detecting sensor which performs detection of a sheet edge in a direction intersecting with a sheet conveyance direction; a punch-unit moving device which moves the punch unit in the direction intersecting with the sheet conveyance direction; a sheet detecting sensor which performs detection of a sheet position in the sheet conveyance direction; and a controller portion which performs control such that after skew of the sheet is corrected by the registration roller pairs in accordance with detection results of skew amount sensors, and punching is performed on the sheet by the punch-unit moving device and the punch driving portion in accordance with a detection result of the sheet detect

Abstract: A sheet processing apparatus which is capable of improving operability while suppressing an increase in apparatus size. In a front cover insertion mode, an insertion sheet for a front cover is inserted into a bundle of sheets on which images have been formed, and in a rear cover insertion mode, an insertion sheet for a rear cover is inserted into the bundle of sheets. Insertion sheets for the front cover and insertion sheets for the rear cover are set with the same orientation in a manual feed tray 105. An insertion sheet for the front cover stored in the manual feed tray 105 is conveyed to a finisher 500 in one of a face-down state and a face-up state. An insertion sheet for the rear cover stored in the manual feed tray 105 is conveyed to the finisher 500 in the other of the face-down state and the face-up state. The insertion sheets for the front cover and for the rear cover conveyed from the manual feed tray 105 and the sheets on which images have been formed are stacked on the finisher 500.

Abstract: The present invention is characterized in a sheet processing apparatus comprising a sheet processing device which binds a sheet stack with a binder and cuts off an excess part of the binder; a first containing portion which contains at least one binder excess cut off by the sheet processing device; a second containing portion which can contain the at least one binder excess contained in the first containing portion; and a controller which controls movement of the at least one binder excess contained in the first containing portion to the second containing portion on the basis of the volume of the at least one binder excess in the first containing portion.

Abstract: A sheet stacking apparatus which is capable of efficiently stacking sheets of various sizes while efficiently using space therein to thereby realize compactness thereof, and maintaining a high availability. Stacker trays for stacking sheets discharged from an image forming apparatus can be separately removed. It is detected whether any of the stacker trays is removed. When large-size sheets are stacked, a stacker control section causes the stacker trays to operate as one tray to stack the sheets in a state extending on the stacker trays, whereas when small-size sheets are stacked, the section causes one of the stacker trays to stack the sheets. Further, when one stacker tray is removed to make it impossible to stack the large-size sheets, the section causes a display section to display a guide message advising setting of the removed stacker tray.

Abstract: A sheet stacking apparatus which is capable of efficiently stacking sheets of various sizes while making efficient use of space therein to realizing compactness of the apparatus. Stacker trays that are driven by respective tray lift motors perform a lifting/lowering operation to have sheets stacked thereon. Selection is made according to the size of sheets between a first stacking mode for stacking sheets having a size not larger than a predetermined size on one of the stacker trays and a second stacking mode for stacking sheets having a size larger than the predetermined size in a state extending on the stacker trays. When it is determined that one of the stacker trays is faulty, execution of the second stacking mode is inhibited, and execution of the first stacking mode using the other stacker tray is permitted.

Abstract: A sheet processing apparatus which is capable of accurately superimposing or aligning sheets discharged from an image forming apparatus during buffering even when the space intervals between the sheets are reduced. A sheet processing apparatus sequentially receives sheets discharged from an image forming apparatus and carries out post-processing on the sheets. During execution of the post-processing on the sheets, a plurality of sheets are discharged successively from the image forming apparatus and superimposed one upon another around a buffer roller. The conveying speed of the sheets is controlled such that a conveying time period over which a sheet preceding a final one of the sheets to be superimposed one upon another around the buffer roller is conveyed over a predetermined path section is shorter than a conveying time period over which the final one is conveyed over the predetermined path section.

Abstract: A sheet processing apparatus includes a stack tray, a stapler, a stapler moving device, and an aligning member. When a stapling process is performed at least two staple positions of the sheet bundle stacked on the stack tray using the stapler, the stapler is moved to the next staple position by relative movement in which the stapler and the sheet bundle are moved in the opposite directions by the stapler moving device and the aligning member respectively. When the number of sheets in the sheet bundle or a weight of the sheet bundle is lower than a predetermined value, a moving speed of the sheet bundle is set faster than a moving speed of the sheet bundle at which the number of sheets in the sheet bundle is not lower than the predetermined value or the weight of the sheet bundle is not lower than the predetermined value.