EP0358954A1 - Bildaufnahmegerät - Google Patents

Bildaufnahmegerät Download PDF

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Publication number
EP0358954A1
EP0358954A1 EP89114921A EP89114921A EP0358954A1 EP 0358954 A1 EP0358954 A1 EP 0358954A1 EP 89114921 A EP89114921 A EP 89114921A EP 89114921 A EP89114921 A EP 89114921A EP 0358954 A1 EP0358954 A1 EP 0358954A1
Authority
EP
European Patent Office
Prior art keywords
sheet material
sheet
passage
refeeding
reversing
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.)
Granted
Application number
EP89114921A
Other languages
English (en)
French (fr)
Other versions
EP0358954B1 (de
Inventor
Shinji Goto
Hiroo Kobayashi
Masao Ando
Takamasa Sawada
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.)
Canon Inc
Original Assignee
Canon Inc
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
Priority claimed from JP63201618A external-priority patent/JPH0729736B2/ja
Priority claimed from JP63202028A external-priority patent/JP2756979B2/ja
Application filed by Canon Inc filed Critical Canon Inc
Publication of EP0358954A1 publication Critical patent/EP0358954A1/de
Application granted granted Critical
Publication of EP0358954B1 publication Critical patent/EP0358954B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/23—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 specially adapted for copying both sides of an original or for copying on both sides of a recording or image-receiving material
    • G03G15/231—Arrangements for copying on both sides of a recording or image-receiving material
    • G03G15/232—Arrangements for copying on both sides of a recording or image-receiving material using a single reusable electrographic recording member
    • G03G15/234—Arrangements for copying on both sides of a recording or image-receiving material using a single reusable electrographic recording member by inverting and refeeding the image receiving material with an image on one face to the recording member to transfer a second image on its second face, e.g. by using a duplex tray; Details of duplex trays or inverters

Definitions

  • the present invention relates to an image recording apparatus such as a laser beam printer, more particularly to an image recording apparatus capable of forming images on both sides of a sheet.
  • a sheet S0 accommodated in a cassette 100 or 101 is fed out by a pick-up roller 102 or 103, and is fed to a neighborhood of a photosensitive drum 105 at the timing determined by a registration roller 104. While the sheet is being fed in this manner, a latent image is formed on the photosensitive drum 105 with a laser beam from a laser unit 106, and the latent image is developed by a developer such as toner. The toner image is transferred from the drum 105 onto the sheet S0, and the sheet S0 is conveyed to an image fixing device 107 where the image is fixed thereon.
  • a flapper 108 disposed adjacent to the fixing device 107 is switched to guide the sheet S0 to a switch-back unit 102 disposed in the front side of the apparatus, so that the sheet S0 reaches a reversible roller 110.
  • the reversible roller 110 rotates in a direction for discharging the sheet S0 to the outside of the apparatus.
  • a sensor 112 detects the passage of the trailing edge of the sheet S0 through the sheet guide 110, the roller 110 is reversed to direct the sheet S0 to the sheet passages 113a, 113b and 113c formed at the bottom side of the apparatus for refeeding the sheet to form an image on the other side.
  • the most downstream sheet passage 113c extends to the registration roller 104.
  • the conveying passage 113c is provided with a sensor 114 for detecting a sheet, and when the leading edge of the sheet is detected by the sensor 114, the sheet S0 is temporarily stopped, so that the timing of the refeeding is controlled for the second side recording. In this manner, the sheet S0 is reversed in the switch-back unit 109, and is conveyed along the sheet passages 113a, 113b and 113c, by which the printed side of the sheet faces down when the second image is recorded on the sheet SO.
  • a second page image is printed on a first side of a first sheet S1, which is then conveyed into the sheet passages 113a, 113b and 113c, and which is stopped when its leading edge passes by the sensor 114. Then, the second sheet S2 is fed, and it receives an image for its second side, that is, a fourth page image on its first side, and the second sheet S2 is conveyed into the sheet passages 113a, 113b and 113c. At a predetermined interval from the second sheet S2, the first sheet S1 is refed, and it receives an image for its first page on its second side.
  • the sheet S1 is discharged onto the tray 116 through a discharge passage 115, with the first page facing down.
  • a third sheet S3 is fed, and an image for its second side, that is, the sixth page image is formed on its first side.
  • an image for a second page side (first side) for an n-th sheet that is, a 2n-th page image
  • an image for a first page side (second side) of a (n-1)th sheet that is, a (2n-3)th page image
  • an image for a second page side of a (n+l)th sheet that is, (2n+2)th page image
  • an image for a second page side of an N-th sheet that is, a 2N-th page image
  • an image for a first page side of the N-th sheet that is, (2N-1)th page image
  • the N-th sheet S N is discharged on the tray 116 with its second page side, that is, the 2N-th page facing up.
  • the sheet stopping position is disposed after the switch-back station.
  • it will result in a complicated structure of the sheet passages, and it requires a complicated sheet conveying control in accordance with the sizes of the sheet, with the result of increased cost.
  • the length of the recording sheet passage through which the sheet is conveyed during the second side recording (a first page image) is much longer than when the first side is to be recorded for the second page image, and therefore, the recording sheet is laterally (perpendicular to the direction of the sheet conveyance), deviated and therefore, the position of the second side image is deviated.
  • an abutment guide or the like for controlling the lateral position of the recording sheet 52 is disposed at a proper position, for example, a position indicated by a reference C in a passage for the second side recording.
  • the recording sheet S0 is refed to the recording station 105 after it is adjusted in its lateral position (the adjustment will hereinafter be called "lateral registration ⁇ ).
  • the abutment guide has to be adjusted each time the size of the recording sheet changes, which is cumbersome.
  • the recording sheet is more easily jammed, and the apparatus becomes bulky with increase of cost.
  • an image forming apparatus wherein an image is formed on a sheet fed from sheet feeding means by image recording means; the recorded sheet is reversed by sheet reversing means and is refed to the image recording means; the sheet reversing means is disposed downstream of the sheet refeeding passage with respect to movement direction of the sheet in the manner that the sheet is reversed by the sheet reversing means in a projection area of the sheet feeding means.
  • a sheet having received an image on its first side is reversed in its facing orientation by the sheet reversing means and is refed to the image recording means through a refeeding passage. At this time, the sheet is reversed in a projection area of the sheet feeding means, and therefore, the space for the sheet reversing is not extended out of the apparatus horizontally.
  • the second sheet Since the sheet reversing means is disposed downstream of the sheet refeeding means with respect to the sheet conveyance direction, the second sheet is recorded at a predetermined interval and can be introduced into the refeeding passage at the time of plural sheet duplex printing operation even if the first sheet is waiting for the refeeding. This is because the vacant passage is sufficient for accommodation of the second sheet.
  • the sheet reversing action for the second image formation on the same sheet is performed in the projection area of the sheet feeding means, and therefore, the switch-back station is not projected out of the main assembly, whereby the size of the entire apparatus can be reduced.
  • the sheet reversing means is disposed downstream of the sheet refeeding means, the time loss otherwise required for the first and second sheet recording during the continuous duplex print operation, can be reduced.
  • the control of the sheet reversing means can be easily and independently performed.
  • the length of the refeeding passage can be reduced, and the first print can be quickly produced.
  • an image forming apparatus wherein a recording sheet is fed from a sheet feeding station to a recording station where an image is formed; the recording sheet is reversed in a reversing station and is refed to the recording station for formation of a second image, the reversing station and the feeding station are formed as a unit, and a lateral registration means for lateral registration of the recording sheet is provided in the reversing station.
  • the lateral registration is adjusted.
  • the lateral registration can be performed without the conventional cumbersome operation even if the size of the recording sheet changes.
  • the adjusting means and the sheet feeding station constitute a unit, the size of the recording apparatus is not increased.
  • the recording sheet can be easily removed by taking the feeding station out.
  • FIG. 2 there is shown an exemplary image recording apparatus of an electrophotographic type according to an embodiment of the present invention, wherein the image recording apparatus is shown as comprising a photosensitive drum 1 (an image bearing member), on which a latent image is formed by a laser beam from a laser unit 2.
  • the latent image is developed with toner in a process unit 3 (image recording station), the process unit 3 having as an integral part the photosensitive drum 1.
  • sheet feeding means 30 for feeding a sheet, wherein two cassettes 4a and 4b for accommodating sheets S are disposed in two stages.
  • the topmost sheet S in the cassette 4a or 4b is picked up by a pick up roller 5a or 5b and is separated from the remainder with certainty by a sheet feeding roller 6a or 6b and a double-feed preventing roller 7a or 7b, to a registration roller 8.
  • image fixing device 9 for fixing the toner image transferred onto the sheet S.
  • sheet discharge passage 10 and a discharge station G1 for a simplex print Designated by a reference numeral 12 is a flapper for switching the sheet conveyance.
  • reversing passages 13a, 13b and 13c functioning as a sheet refeeding passage for the purpose of the recording on the second side of the sheet.
  • the sheet S having the fixed image on its first side is refed to the neighborhood of the registration roller 8 by a pair of conveying rollers 20 and 21.
  • a sheet switch-back station 14 functioning as the sheet reversing means is disposed below the cassette 4b.
  • the switch-back station 14 comprises trays 14a and 14b for supporting the sheet to be switched back (reversed), a flapper 14c for selectively directing the sheet S conveyed from the sheet reversing passage 13b either to the trays 14a and 14b or to the sheet reversing passage 13b, a sensor 14d for detecting a trailing edge of the sheet S introduced into the switch-back station 14 and the trailing edge of the sheet S to be refed to the process unit from the switch-back station 14, and a pair of reversible rollers 14e for switching-back the sheet S.
  • the switch-back station 14 is so constructed as being retractable from the main assembly 100 together with the pick-up rollers 5a and 5b, feeding rollers 6a and 6b and the double-feed preventing rollers 7a and 7b. Therefore, the switch-back station can be adjusted after it is taken out of the apparatus.
  • the sheet feeding unit is provided with an unshown base plate and a CPU (central processing unit), so that not only the mechanical adjustment of the unit but also electric and soft inspection can be all adjustable within the unit.
  • the switch-back station is constituted as a unit 1; the sheet feeding station is constituted as a unit 2; and the sheet guiding portion is constituted as a unit 3.
  • the units 1 and 3 may be optional.
  • the operation of the switch-back station 14 will be described.
  • An image is recorded on a first side of a sheet S, and then the sheet S is conveyed to the switch-back station 14 through the reversing passages 13a and 13b.
  • the flapper 14c is laid down as shown by chain lines in Figure 2.
  • the conveying rollers 20 and 21 are driven by a duplex print conveying motor to advance the sheet S to the trays 14a and 14b of the switch-back station (time A in Figure 3).
  • the flapper 14c is erected as shown by solid lines in Figure 2 (time B, Figure 3).
  • the reversible roller 14e is reversed (time C, Figure 3), by which the sheet S is refed for the second side image print.
  • the duplex print conveying motor is stopped to prevent the next sheet S from being fed.
  • the reversible roller 14e is stopped (time D in Figure 3) after a predetermined time period elapses from passage of the leading edge of the refed sheet (the trailing edge before being switched back) by the sensor 14d. Then, it waits for the main apparatus 100 to produce the image signal for the second side print to enable the recording operation, so that the image signal and the sheet refeeding are timed.
  • the switch-back station 14 is disposed below the cassette 4b substantially within a projection area of the cassette 4b. Therefore, the switch-back station is not projected out of the main assembly of the apparatus, as contrasted to the conventional apparatus, and therefore, the size of the apparatus can be reduced.
  • the switch-back station 14 is accommodated in the sheet feeding unit and since the CPU for controlling the sheet feeding unit is accommodated in the sheet feeding unit, the mechanism for feeding the sheet S to the process unit 3 (the image recording station) can be all adjusted and inspected independently.
  • the stoppage of the sheet S for waiting for the refeed instruction signal is independently performed by the switch-back station 14 disposed downstream of the reversing passage, and therefore, even if the first sheet S1 is waited for the refeeding, it is possible to stop the driving motor for the second side image formation conveyance for conveying the next sheet S2, a predetermined period after the stoppage of the first sheet S1. In other words, the simultaneous stoppage is not required. As a result, it is possible that the first sheet S1 is fed, and thereafter the second sheet S2 is feed at a predetermined interval between the sheets.
  • the image recording control may be to form the images in the following order as shown in Figure 4: a second page side of the first sheet (a second page, step (1)), a second page side of the second sheet (s fourth page, step (2)), a first page side of the first sheet (a first page, step (3)), a second page side of the third sheet (a sixth page, step (4)), a first page side of the second sheet (a third page, step (5)), a second page side of a fourth sheet (an eighth page, step (6)), ---, a second page side of an n-th sheet, a first page side of the (n-1)th sheet, a second page side of an (n+l)th sheet, ---, a second page side of an N-th sheet (a 2N page, step (2N-2)), a first page side of the (N-­1)th sheet ((2N-3)th page, step (2N-1)), and a first page side of an N-th sheet (a (2N-1)th page,
  • the sensor 14d for the switch-back control also functions as a sensor for the sheet refeeding, whereby the controls which are important for the duplex print can be concentrated on this area. Therefore, the attention may be paid on this area regarding the mechanical accuracy or the like, and the attention may be paid only the sheet jam regarding the other portions. This makes easier the arrangement of the part and the electric control.
  • the switch-back station 14 of this embodiment does not involve a wasteful part, and therefore, the reversing passage required for the second side recording can be made shorter, whereby the speed of the first print can be increased.
  • the switch-back station 14 can be used as a third sheet feeding inlet by inserting the sheet S directly from the outside, so that the utility of the apparatus can be increased.
  • a relatively larger space is provided at a mering point between the most downstream reversing passage 13c and the switch-back station 14.
  • the sensor 14d for detecting the trailing edge of the sheet S is disposed adjacent the upstream side of the conveying roller 21.
  • the flapper 14c takes normally the chain line position, and the rollers 14e are normally spaced apart.
  • the flapper 14c is erected to direct the trailing edge of the sheet to the most downstream reversing passage 14c.
  • the rollers 14e are contacted to grip the sheet S to enable the conveyance of the sheet by them.
  • the switch-back operation can be effected without reversing the roller 14e, and therefore, the mechanism and the control can be made simpler.
  • the apparatus comprises a tray 32 for stacking the sheets S thereon, a flapper 33 and a sensor 34 having the similar functions as in the foregoing embodiments, an upper reversible roller 35a, a lower double-feed preventing roller 35b, a pick-up roller 36 for picking up the sheet S in the tray 32.
  • the double-feed preventing roller 35b normally rotates in the direction indicated by an arrow B and is connected with an unshown torque limiter, so that the roller 35b is stopped or rotated in the opposite direction when the torque over a predetermined level is applied to the roller 35b.
  • N sheets are continuously fed out of the cassette 4a or 4b, and the images of the first, third, fifth, ---, (2N-1)th pages are recorded on the first sides.
  • the printed sheets S are introduced into the switch-back station through the reversing passages 13a and 13b.
  • the flapper 33 takes the chain line position, and the reversible roller 35a rotates in the direction indicated by an arrow Q.
  • the pick-up roller 36 is at the chain line position, that is, it is spaced apart from the sheet S. Therefore, the sheets S having the first side images are stacked in the tray 32 with the printed side facing down and with the N-th sheet on the top.
  • the sheet length and the sheet width can be set in accordance with the size of the sheet is used, manually or automatically.
  • the reversible roller 35a reverses its rotation to rotate in the direction R at time B1, so as to advance the sheet S fed out by the pick-up roller 36 toward the most downstream reversing passage 14c. If plural sheets S are introduced into between the reversible roller 35 and the double-feed preventing roller 35b, the double-feed preventing roller 35b rotating in the direction P functions to return the bottommost sheet S back into the tray 32. On the other hand, only one sheet is introduced into therebetween, the torque limiter operates so that the double-feed preventing roller 35b follows the sheet S conveyed by the reversible roller 35a. The leading edge of the refed sheet by the reversible roller 35a is detected by the sensor 34 (time D1).
  • the reversible roller 35a stops (time E1). At this time, the leading edge of the sheet abuts the nip formed between the registration rollers 8, and a loop or curve of the sheet is formed. Then, the registration rollers 8 are started to rotate to advance the sheet S into the image recording station (time F1) to effect the second side image formation on the sheet S. At the time when the trailing edge of the sheet passes by the sensor 34 (time G1), the next sheet S is fed out from the tray 32 (time H1). The image recording on the second page size are performed in the order of 2N page, (2N-2) page, ---, 2 page. Therefore, on the reverse tray 11, N sheets S are stacked with the first page on the top and facing up.
  • the description will be made as to the case where the duplex print is performed only on a single sheet S.
  • the reversible roller 35a is reversed to effect the refeeding operation.
  • the sheet S is not required to be stacked on the tray 32, and therefore, the printing speed is increased.
  • the pick-up roller is engageable to and disengageable from the sheet S, but the pick-up roller may be in a different type, for example, a crescent roller.
  • the roller is stationary, while the tray 32 is movable to establish a press-contact between the roller and the topmost sheet S.
  • the tray 32 may be constituted as being detachable from the main assembly 100, as in a cassette. In that case, it is usable as a third cassette.
  • the method of separating the sheet S in the tray 32 may be in the form of a friction separation type using a separation pad.
  • flapper means 43 and 44 are disposed in the merging portion between the most downstream reversing passage 40c and feeding passage.
  • the flapper means 43 and 44 include flappers 43a and 44a and elastic sheets 43b and 44b made of polyester film or the like, respectively.
  • the flapper means 43 guides the sheet S taking the solid line position to direct it in the allows a and b. When it takes the chain line position, it guides the sheet S in the direction c.
  • the flapper 44 taking the solid line position directs the sheet in the directions d and e. When it takes the chain line position, it directs the sheet in the direction f.
  • the sheet S conveyed through the reversing passage 40a and 40b is returned by the operation of the flappers 43 and 44 either to the cassette 4a or to the cassette 4b (preferably to the cassette from which the sheet is fed for the first side print.
  • the reversible rollers 38a and 38b and the double-feed preventing rollers 39a and 39b are operated in the manner described in conjunction with Figures 6 and 7, in accordance with the signals from the sensors 45 and 46.
  • the crescent pick-up rollers 37a and 37b are rotated in the direction opposite to the sheet feeding direction.
  • the size of the apparatus can be reduced; and in addition, since the sheet S fed out of a cassette is returned to the same cassette after the first side print, a regulating member for changing the sheet S conveying direction in accordance with the size of the sheet S, can be omitted. It is not inevitable that the sheets S are accommodated in the cassette, since the reversible roller is rotated forwardly and backwardly for one sheet to switch back it to perform the duplex print.
  • the sheet feeding roller can be commonly used for the first side print and for the second side print, by which the variation in the interval between the sheet feed for the first side print and the sheet feed for the second side print, can be reduced.
  • the present invention is not limited to the duplex print, but it is applicable to a superposing print in which plural images are recorded on the same side of the sheet S.
  • an image recording apparatus 51 includes a detachably mountable sheet feeding station 52 in the form of a sheet feeding cassette or a sheet feeding tray accommodating recording sheets P to be fed into the image recording apparatus 51.
  • the sheet feeding station 52 has recording sheet setting plates 52a and 52b for regulating lateral positions of the recording sheets P, and a raising plate 52c for raising the leading edge P′ of the recording sheet P to a predetermined level.
  • a sheet feeding roller 53 is rotatable in the direction indicated by an arrow to feed the recording sheet P out of the feeding station 52.
  • the sheet is then conveyed by a registration roller 54 to a recording station which will be described hereinafter.
  • the image recording apparatus further comprises a laser scanner 55, a reflection mirror 56, the recording station 57 which includes a photosensitive drum 57a, a charger 57b, a developing device 57c and a cleaner 57d. Therefore, the laser beam 55′ emitted from the laser scanner 55 is projected onto the photosensitive drum 57a through the reflection mirror 56 to form an electrostatic latent image thereon. The latent image is visualized by the developing device 50c, and is recorded on the recording sheet P by the charger 7b.
  • an image fixing station 58 the image recorded on the recording sheet P by the recording station 57 is fixed on the recording sheet.
  • a flapper 59 disposed at the outlet of the fixing station 58 is operated to move in the directions d and e.
  • Discharging rollers 60 are disposed above the fixing station 58 to discharge to the discharge tray 61 the recording sheet P conveyed along the conveying passage A after the image fixing.
  • Reversible rollers 62 function to convey to the reversing station the recording sheet P conveyed through the conveying passage and then to a sheet refeeding passage D.
  • the reversing rollers 62 include a driving roller 62 driven by a driving motor M1 and a plurality of follower rollers 62 contacted to the driving roller 62 to rotate following the rotation of the driving roller 62.
  • the driving motor M1 is driven through a control system (not shown) containing a timer when the duplex print mode is selected on an operation panel (not shown).
  • the timer is activated to once stop the rotation of the driving roller 62a when the detecting means K detects the trailing edge of the recording sheet P, as shown in Figure 13B. After a predetermined period of time, the timer is deactuated to rotate the driving roller 62a in the reverse direction, as shown in Figure 13C.
  • the follower roller 62b is supported through a shaft 62d in a groove 62c′ of a bearing 62c which is vertically movable by the rotation of the driving gear 62e driven by a motor M2.
  • the motor M2 is driven by the above-mentioned control system (not shown), and when the detecting means K detects the trailing edge of the recording sheet P, an unshown timer is actuated to rotate the driving gear 62e in the direction X to move the follower roller 62b away from the driving roller 62a to stop it. After a predetermined period of time, the timer is deactuated to rotate the driving gear 62e in the direction Y to bring the follower roller 62b into contact with the driving gear 62a.
  • the groove 62c′ is formed so as to have a larger width adjacent one end of the shaft 62d.
  • the follower roller 62b is horizontally swingable within a predetermined angle, as shown by the chain lines.
  • the reversing station for reversing the recording sheet P is integrally formed at a lower side of the recording sheet feeding station 52.
  • the reversing station 63 is to reverse the recording sheet P which has been conveyed through the recording station 57, the fixing station 58, the conveying passage B and the conveying roller B′.
  • the reversing station 63 is provided with adjusting means 64 which adjusts the lateral position of the recording sheet P conveyed to the reversing station 63.
  • the adjusting means 64 in this embodiment, is in the form of a pair of guiding members 64a spaced from each other with an interval equal to the width of the recording sheet P accommodated in the sheet feeding station 52.
  • the guiding members 64a are extended in the direction of the sheet conveyance.
  • Figures 16A and 16B show another example of the adjusting means.
  • a pinion 72d is rotatable supported adjacent a center between the recording sheet setting plates 72a and 72b, and the opposing surfaces of the recording sheet setting plates 72a and 72b are formed into a projections 72a′ and 72b′ having racks 2e meshable with the pinion 72d.
  • a groove 72f is formed in a bottom surface of the feeding station 72.
  • a connecting part 72g is extended from the bottom surface of each of the recording sheet setting plates 72a and 72b toward the reversing station 83, and a diving member 84a is connected to the connecting portion 72g.
  • the guiding members 84a also slide in the lateral direction.
  • Figure 19 shows a further embodiment, wherein the present invention is applied to an image forming apparatus of a two stage cassette type.
  • the process of recording an image on the recording sheet is the same as the foregoing embodiments, and therefore, the detailed description thereof is omitted.
  • the conveyance of the recording sheet in the duplex print mode will be described.
  • the recording sheet P fed out of the upper cassette 202A is subjected to the image fixing operation by the fixing device 58 for the first image.
  • the flapper 59 it is conveyed to the conveying roller B′ along the conveying passage B.
  • the flapper 230 it is passed through conveying passages 233 and 234, and further by a flapper 235, it is passed through a conveying passage 236.
  • the sheet is then advanced by a reversing roller 217A into the reversing station 213 disposed below the cassette 52A. Thereafter, the sheet is subjected to the lateral registration operation which has been described in the foregoing embodiment. Then, the sheet is fed along the conveying guide 237 by the reversing roller 217A, so that it is subjected to the image recording operation on the other side, that is, the side opposite to the side having the first image.
  • the recording sheet P fed from the lower cassette 202B is conveyed through the conveying passage 234, and is advanced into the recording station 57 through the conveyance passage 238 by the flapper 235, so that a first image is recorded on the recording sheet P.
  • the sheet is then subjected to the image fixing operation by a fixing device 58 for the first image.
  • the sheet is conveyed to the conveying roller B′ through the conveying passage B by the flapper 59.
  • the sheet is directed to the conveying passage 231 by the flapper 230, and is conveyed by the reversing roller 217B into the reversing station 213 disposed below the cassette 202B.
  • the lateral registration operation is imparted to the recording sheet P which is the same as the operation described in the foregoing embodiment.
  • the sheet is then conveyed by the reversing roller 217B along the conveying guide 232, 234 and 238, so that a second image is recorded on the opposite side, that is, the side opposite to the first image bearing side.
  • the two cassette type is taken, but it is possible that it has three or more cassettes.
  • the duplex printing mechanism for various sizes can be provided with a simple structure.
  • the reversing roller 62 is provided in the image recording apparatus 51 side, but it may be disposed in the sheet feeding station 52. It is a possible alternative that a one sheet separating means (for example, a vertically movable feeding roller is provided to the adjusting means side of the roller 62, and the sheets are separated one by one by the roller 62) is provided to temporarily accommodate the plural recording sheets.
  • the present invention is not limited to the case of the duplex print, but is applicable to the superimposing print.
  • the recording sheet P in the feeding station 52 is fed out by the feeding roller 53 and is fed into the recording station 56 through the registration roller 54.
  • the sheet is then subjected to the image recording operation on the first side, and thereafter, the image is fixed on the recording sheet P in the fixing station 58.
  • the flapper 59 takes the position indicated by an arrow d, so that the recording sheet P after the image fixing operation is discharged onto the discharging tray 61 through the conveying passage A and the discharging roller 60.
  • the recording sheet P is introduced into the fixing station 58 in the similar manner described above.
  • the flapper 59 is rotated in the direction e, so that the recording sheet P is conveyed to the reversing roller 62 through the conveying passage B and the conveying roller B′ ( Figure 13A).
  • the motor M1 for rotating the driving roller 62a stops, and the timer is actuated, and simultaneously the motor M2 is actuated to drive the driving gear 62e in the direction X.
  • the recording sheet P which has been subjected to the reversing and lateral registration operations is conveyed into the recording station 56 through the registration roller 54.
  • the image is formed on the second side, that is, the side opposite to the side having the first image.
  • the sheet is discharged onto the discharging tray 61 through the image fixing station 58, the conveying passage A and the discharging rollers 60.
  • the flapper 59 has been rotated in the direction indicated by d.
  • the operations are the same as with Figure 11 embodiment.
  • An image recording apparatus includes a sheet material accommodating device for accommodating sheet materials, a sheet material feeding device for feeding the sheet materials from the sheet material accommodating device, an image recording device for recording images on the sheet materials fed by the feeding device, sheet material refeeding device for refeeding to the image recording device through a refeeding passage the sheet material on which an image has been formed by the image recording device, a sheet material reversing device for reversing the sheet material and conveying it to the image recording device, the sheet material reversing device being disposed downstream of the refeeding passage with respect to a movement direction of the sheet material substantially within a projection area of the sheet material accommodating device.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Conveyance By Endless Belt Conveyors (AREA)
  • Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)
EP89114921A 1988-08-12 1989-08-11 Bildaufnahmegerät Expired - Lifetime EP0358954B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP63201618A JPH0729736B2 (ja) 1988-08-12 1988-08-12 画像記録装置
JP201618/88 1988-08-12
JP202028/88 1988-08-15
JP63202028A JP2756979B2 (ja) 1988-08-15 1988-08-15 画像記録装置

Publications (2)

Publication Number Publication Date
EP0358954A1 true EP0358954A1 (de) 1990-03-21
EP0358954B1 EP0358954B1 (de) 1996-04-24

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP89114921A Expired - Lifetime EP0358954B1 (de) 1988-08-12 1989-08-11 Bildaufnahmegerät

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EP (1) EP0358954B1 (de)
DE (1) DE68926327T2 (de)

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DE4002785A1 (de) * 1989-02-01 1990-08-02 Ricoh Kk Verfahren zum erzeugen beidseitiger kopien in einer bilderzeugungseinrichtung
DE19622167B4 (de) * 1995-06-07 2008-03-27 Eastman Kodak Company Bilderzeugungsvorrichtung mit Duplexpfad und Blatt-Wendevorrichtung
EP3528056A1 (de) * 2018-02-19 2019-08-21 OCE Holding B.V. Verfahren zur korrektur von registrierungsfehlern von medienblättern bei doppelseitigem drucken und doppelseitiges drucken dafür

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US4758862A (en) * 1987-04-16 1988-07-19 Kentek Information Systems, Inc. Electrographic printer/copier with duplex printing
US4763166A (en) * 1985-09-27 1988-08-09 Kabushiki Kaisha Toshiba Image forming apparatus
EP0295612A1 (de) * 1987-06-16 1988-12-21 Canon Kabushiki Kaisha Verfahren zur Steuerung einer Vorrichtung zum beidseitigen und mehrfachen Kopieren

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US4724460A (en) * 1985-06-28 1988-02-09 Kabushiki Kaisha Toshiba Copying device
US4763166A (en) * 1985-09-27 1988-08-09 Kabushiki Kaisha Toshiba Image forming apparatus
US4758862A (en) * 1987-04-16 1988-07-19 Kentek Information Systems, Inc. Electrographic printer/copier with duplex printing
EP0295612A1 (de) * 1987-06-16 1988-12-21 Canon Kabushiki Kaisha Verfahren zur Steuerung einer Vorrichtung zum beidseitigen und mehrfachen Kopieren

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PATENT ABSTRACTS OF JAPAN *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4002785A1 (de) * 1989-02-01 1990-08-02 Ricoh Kk Verfahren zum erzeugen beidseitiger kopien in einer bilderzeugungseinrichtung
DE19622167B4 (de) * 1995-06-07 2008-03-27 Eastman Kodak Company Bilderzeugungsvorrichtung mit Duplexpfad und Blatt-Wendevorrichtung
EP3528056A1 (de) * 2018-02-19 2019-08-21 OCE Holding B.V. Verfahren zur korrektur von registrierungsfehlern von medienblättern bei doppelseitigem drucken und doppelseitiges drucken dafür

Also Published As

Publication number Publication date
DE68926327T2 (de) 1996-10-02
DE68926327D1 (de) 1996-05-30
EP0358954B1 (de) 1996-04-24

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