EP0859289A2 - Empileur de feuilles pour éviter de feuilles absents et appareil d'impression avec l'empileur de feuilles - Google Patents

Empileur de feuilles pour éviter de feuilles absents et appareil d'impression avec l'empileur de feuilles Download PDF

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Publication number
EP0859289A2
EP0859289A2 EP97307961A EP97307961A EP0859289A2 EP 0859289 A2 EP0859289 A2 EP 0859289A2 EP 97307961 A EP97307961 A EP 97307961A EP 97307961 A EP97307961 A EP 97307961A EP 0859289 A2 EP0859289 A2 EP 0859289A2
Authority
EP
European Patent Office
Prior art keywords
sheet
path
reversing
printer
ejected
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP97307961A
Other languages
German (de)
English (en)
Other versions
EP0859289A3 (fr
Inventor
Nobuo Fujita
Shoki Iwawaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Publication of EP0859289A2 publication Critical patent/EP0859289A2/fr
Publication of EP0859289A3 publication Critical patent/EP0859289A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/65—Apparatus which relate to the handling of copy material
    • G03G15/6552—Means for discharging uncollated sheet copy material, e.g. discharging rollers, exit trays
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H15/00—Overturning articles
    • B65H15/004—Overturning articles employing rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H29/00—Delivering or advancing articles from machines; Advancing articles to or into piles
    • B65H29/58—Article switches or diverters
    • B65H29/60—Article switches or diverters diverting the stream into alternative paths
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/65—Apparatus which relate to the handling of copy material
    • G03G15/6555—Handling of sheet copy material taking place in a specific part of the copy material feeding path
    • G03G15/6573—Feeding path after the fixing point and up to the discharge tray or the finisher, e.g. special treatment of copy material to compensate for effects from the fixing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2301/00—Handling processes for sheets or webs
    • B65H2301/30—Orientation, displacement, position of the handled material
    • B65H2301/33—Modifying, selecting, changing orientation
    • B65H2301/333—Inverting
    • B65H2301/3331—Involving forward reverse transporting means
    • B65H2301/33312—Involving forward reverse transporting means forward reverse rollers pairs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2511/00—Dimensions; Position; Numbers; Identification; Occurrences
    • B65H2511/50—Occurence
    • B65H2511/52—Defective operating conditions
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
    • G03G2215/00535—Stable handling of copy medium
    • G03G2215/00548—Jam, error detection, e.g. double feeding
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
    • G03G2215/00535—Stable handling of copy medium
    • G03G2215/00548—Jam, error detection, e.g. double feeding
    • G03G2215/00552—Purge of recording medium at jam

Definitions

  • the present invention relates to a sheet stacker and, more particularly, to a large capacity sheet stacker used by being connected to a large scale printer.
  • the sheet stacker is for stacking a large number of printed sheets on a table. Since the large number of sheets are bound, if it is desired, a missing page cannot be allowed. Accordingly, it is required for the sheet stacker to take measures to prevent an occurrence of a missing page.
  • the sheet stacker has a mechanism for reversing sheets, there is a higher possibility of occurrence of a missing page than a sheet stacker which dose not have a sheet reversing mechanism. Thus, it is particularly required for the sheet stacker to take measures to prevent an occurrence of a missing page.
  • FIG.1 shows a conventional large capacity sheet stacker 10.
  • the sheet stacker 10 is operated by being mechanically and electrically connected to a large scale printer 11 as shown in FIG.2.
  • the printer 11 includes a sheet path 12.
  • the end of the sheet path 12 is a sheet eject opening 13.
  • a sheet 14 is fed from a sheet cassette 15, and a front surface of the sheet 14 is printed while the sheet 14 passes a photosensitive drum 17 on which a photostatic latent image is provided by an optical unit 16 and a fixing device 18.
  • the sheet 14 being printed on the front surface is ejected from the sheet eject opening 13 by sheet feed rollers 19, and enters the sheet stacker 10.
  • the sheet stacker 10 comprises a main body 30, a sheet reversing mechanism 31 inside the main body 30 and a sheet table 32 extending from the main body 30.
  • a sheet is switched back by the sheet reversing mechanism 31 in the sheet stacker 10 so that the printed surface is directed downwardly (face down), and the sheet is stacked on the sheet table 32.
  • the lower end of a reversing path 33 which constitutes a part of the sheet reversing mechanism 31 is an opening 34 which responds to various sheet sizes.
  • the sheet stacker 10 stops its operation when an abnormality such as a paper jam occurs in the printer 11, and starts an initializing operation when a recovery of the abnormality is completed and a return command is provided.
  • the initializing operation is performed so as to confirm whether or not a sheet is present in the sheet stacker 10.
  • the initializing operation includes an operation to draw a sheet into the reversing path 33, and an operation to feed a sheet out of the reverse path 33.
  • the sheet stacker 10 performs the initializing operation after recovery from an abnormality is completed and the return command is provided, the sheet left in the reversing path 33 is fed further along the reversing path 33, and falls inside the sheet stacker 10 by passing through the opening 34 as indicated by reference numeral 35.
  • a more specific object of the present invention is to provide a sheet stacker which prevents a sheet remaining in a reversing path from falling inside the sheet stacker when an initializing operation is performed.
  • a sheet stacker for use with a printer adapted to eject a sheet having a printed surface, the sheet stacker comprising:
  • the sheet stacker comprises the sheet purge table and the sheet purge path provided between the lower end of the reversing path and the sheet purge path, and the sheet remaining in the sheet reversing mechanism is ejected on the sheet purge table by passing through the sheet purge path.
  • the sheet ejected from the sheet reversing mechanism is placed on the sheet table when the initializing operation is performed, that is the sheet is placed on the sheet purge table after the initializing operation has been completed.
  • the operator will realize the sheet placed on the sheet purge table before binding the sheets stacked on the table. Accordingly, the operator will pick up the sheet on the sheet purge table, and insert the sheet in the right place in the stacked sheets before binding the sheets.
  • binding of the sheets without realizing that a sheet is missing is effectively prevented.
  • a sheet stacker for use with a printer adapted to eject a sheet having a printed surface, the sheet stacker comprising:
  • the stopper member is mounted on a portion of the reversing path.
  • a sheet remaining in the sheet reversing mechanism is ejected onto the table after being engaged with the stopper member by the initializing operation performed after recovery from an abnormality.
  • a sheet stacker for use with a printer adapted to eject a sheet having a printed surface, the sheet stacker comprising:
  • the stopper member is movably provided in the downward direction at a portion in the middle of the reversing path. Additionally, an urging means for upwardly moving the stopper member to the original position is provided. A force generated by the urging means is set to be smaller than the force exerted by the end of the sheet being fed. Thus, the end of the sheet in the sheet reversing mechanism presses down the stopper member against the force generated by the urging means, and thereafter the sheet is ejected onto the table. Thus, a missing page can be prevented when the sheets stacked on the table are bound. Additionally, since the stopper member is movable downwardly, the sheet stacker can handle all size sheets. Accordingly, adjustment is not needed when the sheet size is changed, which is very convenient for use.
  • a sheet stacker for use with a printer adapted to eject a sheet having a printed surface, the sheet stacker comprising:
  • the sheet receiver is provided at the lower end of the reversing path
  • the sheet sensor is provided near the lower end of the reversing path so as to detect the sheet received by the sheet receiver.
  • the sheet located in the sheet reversing mechanism is detected by the sheet sensor since the sheet falls on the sheet receiver by the initial operation performed after recovery from an abnormality. Accordingly, the operator can realize that the sheet that fell on the sheet receiver before binding the sheets stacked on the table. Thus, the operator will insert the sheet on the sheet receiver into the correct position, and then bind the sheets. Thus, binding without realizing that a page is missing can be effectively prevented.
  • a sheet stacker for use with a printer adapted to eject a sheet having a printed surface, the sheet stacker comprising:
  • the sheet since the means for rendering the sheet reversing mechanism to return the sheet remaining in the reversing path toward the sheet at the beginning of the initializing operation performed after recovery from an abnormality of the printer, the sheet can be positively prevented from falling in the interior of the sheet stacker. Thus, a missing page when binding the sheets can be prevented.
  • a printer can be provided having a sheet stacker device similar to one of the sheet stackers according to the present invention.
  • FIG.3 shows a sheet stacker 40 according to a first embodiment of the present invention.
  • the sheet stacker 40 is mechanically and electrically connected to a large scale printer 11 as shown in FIG.4.
  • a sheet receiving opening 60 of the sheet stacker 40 faces a sheet eject opening 13 of the printer 11.
  • the printer 11 includes a sheet path 12.
  • the end of the sheet path 12 is a sheet eject opening 13.
  • a sheet 14 is fed from a sheet cassette 15, and a front surface of the sheet 14 is printed while the sheet 14 passes a photosensitive drum 17 on which a photostatic latent image is provided by an optical unit 16 and a fixing device 18.
  • the sheet 14, having being printed on the front surface, is ejected from the sheet eject opening 13 by sheet feed rollers 19, and the sheet 14 enters the sheet stacker 10.
  • the sheet stacker 40 comprises a main body 50, a sheet reversing mechanism 51 inside the main body 50, a sheet table 52 extending from the main body 50, a sheet purge path 53, and a purge table 54.
  • the sheet purge path 53 is connected to the lower end of a reversing path 63, and extends in an oblique and downward direction.
  • the lower end of the sheet purge path 53 is a sheet eject opening 55 which is located in a portion of the main body under the sheet table 52.
  • the purge table 54 is provided directly under the sheet eject opening 55.
  • the sheet reversing mechanism 51 switches the back and front of a sheet so as to turn the sheet with the printed surface facing downwardly.
  • the sheet reversing mechanism 51 comprises a sheet receiving opening 60; a sheet eject opening 61; a receiving path 62 which extends from the sheet receiving opening 60 so as to receive a sheet ejected from the printer; a reversing path which extends from the receiving path 62 and extends in a vertically downward direction; an eject path 64 between a top portion of the reversing path 63 and the sheet eject opening 61; a sheet feed roller 65 provided in the receiving path 62; a sheet feed roller 66 provided in the reversing path 63; a first motor 68; a second motor 69; a guide member 70 in the receiving path 62; a first sheet passage sensor 72 provided in the receiving path 62 to detect passage of a sheet; and a second sheet sensor 73 provided in the eject path 64 to detect passage of a sheet.
  • the first motor 68 rotates the sheet feed roller 65 via a gear 74.
  • the second motor 69 rotates the sheet feed rollers 66 and 67 via a belt 75 engaged with the sheet feed rollers 66 and 67 and a pulley of the second motor 69.
  • Each of the sheet feed rollers 65, 66 and 67 is pressed by a roller so as to make a pair of rollers with the corresponding rollers 65, 66 and 67.
  • the sheet stacker 40 includes, in association with the sheet reversing mechanism 51, a microcomputer 80, a first motor drive circuit 81, a second motor drive circuit 82 and a plunger drive circuit 83.
  • Information from the printer 11 and sheet passage sensors 72 and 73 is provided to the microcomputer 80 so that the microcomputer 80 outputs control signals to the plunger drive circuit 83 and the first and second motor drive circuits 81 and 82.
  • a plunger 71 is driven by the plunger drive circuit 83.
  • the first motor 68 is driven by the first motor drive circuit 81, and second motor 69 is driven by the second motor drive circuit 82.
  • the sheet stacker 40 operates in synchronization with an operation of the printer 11.
  • the sheet stacker 40 normally operates as shown in FIG.6.
  • the first motor is rotated in a normal direction as shown in FIG.6-(B) and the second motor is also rotated in the normal direction as shown in FIG.6-(B).
  • the sheet feed rollers 65, 66 and 67 are rotated as shown in FIG.6-(E).
  • the sheet 14, which was ejected from the printer 11 and entered the sheet stacker 40 through the sheet receiving opening 60, is fed to the receiving path 62 by the sheet feed roller 65.
  • the sheet 14 is then fed to the reversing path 63 by the sheet feed roller 66.
  • the first sheet passage sensor 72 When the rear end of the sheet 14 with respect to a feeding direction passes the first sheet passage sensor 72, the first sheet passage sensor 72 outputs a signal as shown in FIG.6-(C).
  • the first and second motors 68 and 69 continue to rotate from a time t1 when the signal is output until a predetermined time period T1 has passed so that the entire sheet 14 enters the reversing path 63. In this state, the sheet 14 is straightened due to its elasticity, and the rear end of the sheet 14 is directed to the eject opening 64.
  • the first motor 68 is stopped, and the second motor 69 is rotated in the reverse direction.
  • the sheet feed rollers 66 and 67 are rotated as shown in FIG.6-(F).
  • the sheet 14 in the reverse path 63 is fed upwardly by the sheet feed roller 66, and moves out of the reversing path 63 and enters the eject path 64. That is, the sheet 14 is switched back so that the printed surface is directed downwardly, and the sheet 14 is fed so as to be ejected from the sheet eject opening 61 by the sheet feed roller 67.
  • the second sheet passage sensor 73 When the rear end of the sheet 14 passes the second sheet passage sensor 73, the second sheet passage sensor 73 outputs a signal as shown in FIG.6-(D).
  • the second motor 69 continues to rotate from a time t2 when the signal is output until a predetermined time period T2 has passed. Thereby the entire sheet 14 is ejected from the sheet eject opening 61, and the sheet 14 is ejected and stacked on the sheet table 52 with the printed surface down.
  • the micro computer 80 operates as shown in a flowchart of FIG.7.
  • the microcomputer 80 first rotates the first motor 68 and the second motor 68 in the normal direction (step ST1). Then the microcomputer 80 stops the first motor 68 and the second motor 69 after the predetermined time period T1 has passed after the first sheet passage sensor 72 detects the passage of the sheet 14 (steps ST2, ST3 and ST4). When the passage of the sheet 14 is not detected by the first sheet passage sensor 72, an alarm is displayed (step ST9).
  • step ST5 the second motor 69 is reversed (step ST5).
  • the second motor 69 is stopped after the predetermined time period T2 has passed since the second sheet passage sensor 73 detects the passage of the sheet (steps ST6, ST7 and ST8).
  • an alarm is displayed (ST9).
  • a return command is output from the printer 11 and the sheet stacker 40 performs an initializing operation.
  • the initializing operation is performed so as to check if a sheet is remaining in the sheet stacker 40.
  • the initialising operation is performed in two steps.
  • the microcomputer 80 is operated as shown by a flowchart of FIG.9.
  • the first motor 68 and the second motor 69 are rotated in the normal direction (step ST10). Then, the first motor 68 and the second motor 69 are stopped after the predetermined time period T3 has passed (steps ST11 and ST12). Thereafter, the second motor 69 is stopped (step ST13). The second motor is stopped after the predetermined time period T4 has passed.
  • FIG.10-(A) shows the sheet stacker 40 in a state in which operations of the printer 11 and the sheet stacker 40 are stopped due to a paper jam in the printer 11.
  • the sheet 14 has just entered the reversing path 63 of the sheet stacker 40.
  • the return command is output from the printer 11 and the sheet stacker 40 performs the above-mentioned initializing operation.
  • the sheet 14 in the reversing path 63 is fed downwardly by the sheet feed roller 66 rotating clockwise.
  • the above-mentioned time period T3 is set to a time period sufficient for drawing the sheet 14, which has slightly entered the receiving path 62, into the reversing path 63.
  • the rear end (the upper end in FIG.10-(A)) of the sheet 14 with respect to the feeding direction passes the position of the sheet feed roller 66.
  • the sheet 14 passes through the sheet purge path 53 and is ejected onto the purge table 54 outside the main body 50 via the sheet eject opening 55.
  • the initializing operation in the second step is performed irrespective of the sheet 14 being ejected onto the purge table 54.
  • the sheet 14 is still placed on the purge table 54. If the sheet 14 is placed on the purge table 54, the operator can easily realize the occurrence of a missing page.
  • Sheets which are printed in the resumed operation are stacked on the sheets which were already stacked on the sheet table 52 by the sheet stacker 40.
  • the operator will realize the sheet 14 is on the purge table 54, and will pickup the sheet 14 from the purge table 54 and insert it in the correct position in the stacked sheets. Then, the operator can bind the sheets. Thus, a problem that sheets are bound without realizing a page is missing can be effectively prevented.
  • FIG.11 shows a sheet stacker 40A according to a second embodiment of the present invention.
  • the sheet stacker 40A includes a stopper member 90 instead of the purge sheet path 53 and the purge table 54 of the sheet stacker 40 according to the above-mentioned sheet stacker 40.
  • FIGS.11 and 12 parts that are the same as the parts shown in FIG.3 are given the same reference numerals, and descriptions thereof will be omitted. It is assumed that the printer 11 performs printing on A4 size print medium.
  • a portion of the reversing path below the sheet feed roller 66 has a construction in which a wall 91 forming a side of the reversing path 63 is rotated with respect to a hinge 92 so that the reversing path 63 can be opened, if necessary.
  • a wall 91 forming a side of the reversing path 63 is rotated with respect to a hinge 92 so that the reversing path 63 can be opened, if necessary.
  • stopper member mounting portions 93 and 94 are provided on the wall 91.
  • the stopper member 90 is secured to the upper stopper member mounting portion 93 by a screw 95 in response to the A4 size which is the size of the sheet in the printer 11.
  • the stopper member 90 traverses the reversing path 63 as shown in FIG.11
  • a distance L1 between the stopper member 90 and the sheet feed roller 66 is slightly less than a longitudinal dimension C1 of the A4 size sheet provided in a cassette of the printer 11.
  • FIG.13-(A) shows a state in which a paper jam occurs in the printer 11 and the operations of the printer 11 and the sheet stacker 40A are stopped.
  • the A4 size sheet 14 is located in the reversing path 63 of the sheet stacker 40A.
  • the return command is output from the printer 11, and the sheet stacker 40A performs the above-mentioned initializing operation.
  • the sheet 14 in the reversing path 63 is fed downwardly by the sheet feed roller 66 rotating clockwise, and the rear end (the upper end in FIG.10(A)) of the sheet 14 with respect the feeding direction passes the position of the sheet feed roller 66.
  • the end 14b on the leading side of the sheet 14 with respect to the feeding direction contacts the stopper member 90.
  • the sheet 14 is moved further downwardly while the downward movement of the end 14b is restricted by the stopper member 90 contacting the end 14 of the sheet 14.
  • the sheet 14 is trapped between the stopper member 90 and the sheet feed roller 66 in a slightly bent state as shown in FIG.13-(B).
  • the end 14a of the sheet 14 is urged upwardly due to the high bending strength of the sheet 14, that is, the elasticity of the sheet 14 itself, and is pressed against a portion between the sheet feed roller 66 and the roller contacting the sheet feed roller 66.
  • the sheet 14 enters the eject path 64, and is fed by the sheet feed roller 67.
  • the second sheet passage sensor 73 detects the passage of the sheet 14, and the sheet 14 is ejected from the sheet stacker 40A so that the sheet 14 is placed on the sheets stacked on the sheet table 52 with the printed surface facing downwardly.
  • the stopper member 90 is removed from the stopper member mounting portion 93 and is mounted to the lower stopper member mounting portion 94.
  • the sheet stacker 40A is then in a state shown in FIG.14.
  • a distance L2 between the stopper member 90 and the sheet feed roller 66 is slightly less than a longitudinal dimension C2 of the A3 size sheet provided in a cassette of the printer 11.
  • the A3 size sheet is stopped by the stopper member 90, and does not fall inside the sheet stacker 40A and is ejected on the sheet table 52 from the sheet stacker 40A.
  • FIG.15 shows a sheet stacker 40B according to a third embodiment of the present invention.
  • the sheet stacker 40B is generally a variation of the sheet stacker 40A according to the above-mentioned second embodiment.
  • parts that are the same as the parts shown in FIGS.9 and 10 are given the same reference numerals, and descriptions thereof will be omitted.
  • an elongated opening 100 is formed in a wall 91A, and guide members 101 and 102 are fixed on each side of the elongated opening 100.
  • a stopper 103 is provided so that a stopper tab 103a protrudes into the elongated opening 100 and a side rod 103b fits into the guide members 101 and 102.
  • a tension coil spring 105 which acts as a biasing means is bridged between the stopper member 103 and a lug 104 on the wall 91A.
  • the characteristic of the tension coil spring 105 is set so that a spring force is far smaller than the bending strength of the sheet, and is far smaller than a feeding force of the sheet feed roller 66. This is to provide a normal operation of the sheet stacker 40B without problems. Due to the coil spring, the stopper member 103 is located at the highest position with respect to the guide rails.
  • a distance L4 between the stopper tab 103a and the sheet feed roller 66 is slightly shorter than the longitudinal dimension of the minimum size sheet used by the printer 11.
  • FIG.17-(A) shows a state in which a paper jam occurs in the printer 11, and the operations of the printer 11 and the sheet stacker 40B are stopped.
  • the A4 size sheet 14 is located in the reversing path 63 of the sheet stacker 40B. After the operator has completed recovery from the paper jam, the return command is output from the printer 11, and the sheet stacker 40A performs the initializing operation.
  • the sheet 14 in the reversing path 63 is fed downwardly by the sheet feed roller 66 rotating clockwise by the initializing operation in the above-mentioned first step.
  • the end 14b of the sheet 14 abuts the stopper tab 103a, and presses the stopper member 103.
  • the sheet 14 is further moved downwardly by moving the stopper member 103 by extending the tension coil spring 105, and the end 14a passes the position of the sheet feed roller 66.
  • the sheet 14 is set in a state in which the end 14a of the sheet 14 is pressed against a position between the sheet feed roller 60 and the roller contacting the sheet roller 60.
  • the sheet 14 enters the eject path 64, and is fed by the sheet feed roller 66.
  • the second sheet passage sensor 73 detects passage of the sheet 14, and the sheet 14 is ejected from the sheet stacker 40B so that the sheet 14 is placed on the sheets stacked on the sheet table 52 with the printed surface facing downwardly.
  • the stopper 103 is moved to a position lower than that shown in FIG.17-(B). Additionally, the present embodiment can be applied without change even when the size of the sheet 14 is changed. That is, no change with respect to the stopper is required when a sheet size is changed, and thus it is convenient for use.
  • FIG.18 shows a sheet stacker 40C according to a fourth embodiment of the present invention.
  • the sheet stacker 40C has a construction in which the sheet purge path 53 and the purge table 54 are removed from the sheet stacker 40 according to the first embodiment shown in FIG.3 and, instead, the reversing path 63 is extended downwardly, a sheet receiver 120 being provided at the lower end of the reversing path 63, and an actuator type sheet sensor 121 is provided near the lower end of the reversing path 63.
  • the sheet sensor 121 and the sheet receiver 120 are provided below a level H0 of the sheet feed roller 66 as a reference level.
  • a level H1 is a level distant from the level H0 by the length of a sheet having a maximum length Cmax.
  • the sheet sensor 121 is located at a level H2.
  • the level H2 is lower than the level H1. Accordingly, as long as the sheet is caught by the sheet feed roller 66, the sheet sensor 121 does not detect the sheet even if the sheet has the maximum length.
  • the sheet receiver 120 is located at the level H3.
  • the level H3 is lower than the level H2.
  • a distance L10 between the level H2 and the level H3 is less than the above-mentioned length Cmax. Accordingly, when the sheet moves off the sheet feed roller 66 and falls on the sheet receiver 120, the sheet sensor 121 positively detects the sheet even when if the sheet has a minimum length.
  • the operator can recognize that the sheet moved from the sheet feed roller 66 and fell onto the sheet receiver by monitoring an output of the sheet sensor 121. Accordingly, the operator can realize that the occurrence of a missing page prior to binding the sheets stacked on the sheet table 52. This prevents the operator from binding the sheets without realizing that a page is missing.
  • FIG.19 shows a sheet stacker 40D according to a fifth embodiment of the present invention.
  • parts that are the same as the parts shown in FIGS.3 and 5 are given the same reference numerals, and descriptions thereof will be omitted.
  • the sheet stacker 40D comprises, as shown in FIG.19 and also in FIG.20, the main body 50, the sheet reverse mechanism 51 in the main body 50 and the sheet table 52 extending from the main body 50.
  • the initializing operation is performed so as to check if there is a sheet remaining in the sheet stacker 40D.
  • the initializing operation includes the following three steps.
  • the microcomputer 80 operates as indicated by a flowchart shown in FIG.22.
  • the first motor 68 and the second motor 69 are rotated in the reverse direction (step ST20). Then, the first motor 68 and the second motor 69 are stopped (steps ST21 and ST 22).
  • step ST23 It is then determined whether the first sheet passage sensor 72 or the second sheet passage sensor 73 detects the sheet 14 (step ST23). If one of the first sheet passage sensor 72 and the second sheet passage sensor 73 detects the sheet 14, an alarm is displayed (step ST31). Thereafter, the first motor 68 and the second motor 69 are rotated in the normal direction (step ST24). Then, the first motor 68 and the second motor 69 are stopped after the predetermined time period T11 has passed (step ST25 and ST26). Thereafter, the second motor 69 is rotated in the reverse direction (step ST27). After the predetermined time period T12 has passed, the second motor 69 is stopped (step ST28 and ST29).
  • FIG.23 shows a printer 130 according to a sixth embodiment of the present invention.
  • the printer 130 has a structure in which a printer unit 131 and a sheet stacker unit 40E are integrated, the sheet stacker 40E having a structure the same as the sheet stacker 40 shown in FIG.3.
  • the sheet stacker 40E may also have a structure the same as that of the sheet stacker 40A, 40B, 40C and 40D shown in FIGS.11, 15, 18 and 19, respectively.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)
  • Pile Receivers (AREA)
  • Paper Feeding For Electrophotography (AREA)
  • Handling Of Cut Paper (AREA)
EP97307961A 1997-02-14 1997-10-07 Empileur de feuilles pour éviter de feuilles absents et appareil d'impression avec l'empileur de feuilles Withdrawn EP0859289A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP30505/97 1997-02-14
JP9030505A JPH10226448A (ja) 1997-02-14 1997-02-14 用紙スタッカ装置及びプリンタ装置

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EP0859289A2 true EP0859289A2 (fr) 1998-08-19
EP0859289A3 EP0859289A3 (fr) 1998-10-14

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EP97307961A Withdrawn EP0859289A3 (fr) 1997-02-14 1997-10-07 Empileur de feuilles pour éviter de feuilles absents et appareil d'impression avec l'empileur de feuilles

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EP (1) EP0859289A3 (fr)
JP (1) JPH10226448A (fr)

Cited By (2)

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US9682836B2 (en) 2015-05-01 2017-06-20 Konica Minolta, Inc. Sheet conveying device, and image forming apparatus and image forming system including the same
US9969592B2 (en) * 2015-05-01 2018-05-15 Konica Minolta, Inc. Sheet conveying device, and image forming apparatus and image forming system including the same

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Publication number Priority date Publication date Assignee Title
JP5186326B2 (ja) * 2008-09-30 2013-04-17 理想科学工業株式会社 印刷装置のリカバリー機構および用紙搬送装置
JP2014015326A (ja) * 2012-07-11 2014-01-30 Glory Ltd 表裏反転機構および投票用紙分類機

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Publication number Priority date Publication date Assignee Title
US9682836B2 (en) 2015-05-01 2017-06-20 Konica Minolta, Inc. Sheet conveying device, and image forming apparatus and image forming system including the same
US9969592B2 (en) * 2015-05-01 2018-05-15 Konica Minolta, Inc. Sheet conveying device, and image forming apparatus and image forming system including the same

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Publication number Publication date
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EP0859289A3 (fr) 1998-10-14

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