JP3147320B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circulating document feeder provided in a copying machine or the like, in which a plurality of documents are placed on the platen of an image forming apparatus by switching two pages from the lower side and back and forth. More specifically, the present invention relates to an image forming apparatus including a parallel copying unit that conveys a document bundle to an odd number of document bundles.
The present invention relates to a method for controlling the last page of the bundle of originals.

[0002]

2. Description of the Related Art Conventionally, as a method of forming an image of two documents on the same surface of one transfer sheet using a circulating document feeder, Japanese Patent Application Laid-Open No. 60-2942 discloses a method. As described in Japanese Unexamined Patent Application Publication No. 60-84945, Japanese Patent Application Laid-Open No. 60-93462, etc., a method of feeding and placing two originals on a platen from the later page in the transport direction in parallel (hereinafter referred to as parallel). Reading mode).

With respect to the processing order of the originals, if the processing from the first page is performed, the stacking state of the originals and the transfer sheets after copying will be such that the image surface will face downward (face down) and the visibility will decrease. So the discovery of mistakes is delayed. When the processing from the last page is performed, the above problem is solved. However, if the number of originals is odd in the parallel reading mode, the first page (left side of the first sheet) of the transfer sheet becomes blank. .

As a solution to this problem, Japanese Patent Application Laid-Open No. Sho 62-5
In the device described in Japanese Patent No. 5667, a method is employed in which an odd / even setting button is arranged on the operation unit and the control is changed according to the signal. That is, when the odd number is selected by the setting button, the blank of the first page can be avoided by forming an image on one transfer sheet without performing the parallel reading mode on the last page.

<Prior Art 2> FIG. 12 shows an example of a conventional document feeder capable of a parallel reading mode. In the figure, a document P is placed on a document tray 219 with an image facing downward (face down). Document 221 sent out by feed roller 223
Is transported to the platen glass 216 via the transport belts 217 and 218, the first page P ′ is placed at the first original reference position on the left side in the figure, and the second page P ″ is transported to the second page via the transport belt 217. The document is placed at the document reference position.

A reading section 210 having a lamp 205 and a light receiving element 209 is moved left and right in the figure by a drive motor 215 to read images of both originals P 'and P ". In the parallel reading mode, both originals P' are read. , P ″ are copied onto one transfer sheet S as shown in FIG.
The originals P ′ and P ″ after the image processing are discharged to the discharge tray 220.

FIG. 14 shows a second example of a conventional document feeder. In the figure, a document P is placed on a document tray 214 in a face-up state. The document P sent out by the half-moon roller 205 is
06, separated and fed one by one by the separation belt 206,
When the tip is brought into contact with the registration roller pair 208, the sensor 2
15 is detected.

The original P fed by the pair of registration rollers 208 is brought into contact with the platen glass 203 of the image forming apparatus 1 by a transport belt 210 wound around a driving roller 211 and a driven roller 212. In the parallel reading mode, two originals P are sequentially fed, and the first original is placed on the right side of the platen glass 203 in the drawing, and the next original is placed on the left side. FIG. 15 shows a state where both originals P are simultaneously copied onto one transfer sheet S. After image formation,
Both originals P are discharged onto the discharge table 202 by the discharge rollers 213.

FIGS. 16 and 17 show a third example of a conventional document feeder. In the figure, the originals P placed on the original tray 214 in a face-up state are separated one by one from the lowest one, and
0. In the parallel reading mode, the leading m-th page is first fed to the platen glass 210, and this is fed to the platen glass 21 as shown in FIGS.
0, the original of the next page (m-1) is conveyed to the platen glass 210 as shown in FIG.
Thereafter, the m-th page and the (m-1) -th page are simultaneously transported ((d)
(E), as shown in the (e) figures, the parallel reading mode is set to a possible mounting state.

[0010]

However, in the above-described image forming apparatus, blank pages can be avoided, but the setting is troublesome and blank pages are generated if the operation buttons are not set in a predetermined state. .

In the above conventional example, when the last page of an odd number of originals is placed on a normal reference position and a normal transfer process is performed, an image formed on the transfer sheet is formed on the right side. Therefore, a blank page is generated at the position of the first page.

In copying in the parallel copying mode (copying performed in the parallel reading mode), if the transfer sheet is reduced to half the size and the transfer process is performed, the transfer sheet is not necessarily of a general size. I can't say. For example, at the time of reduction from A42 sheets to A4R, the last page has the A5 size, and it is unlikely that the user has this size.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which is an image forming apparatus in a parallel copy mode and which can be easily operated to set an odd number of sheets so that a blank portion does not occur even when the number of originals is an odd number. It is assumed that.

[0014]

The invention according to claim 1 is
The document conveying device includes a parallel copy unit that conveys a document of a plurality of document bundles onto a platen of the image forming apparatus by switching the front and rear order of the preceding document and the following document two by two from the lower side thereof, In an image forming apparatus for forming two sheets of even-numbered sheets and odd-numbered sheets placed in parallel on the platen on a single sheet, if the total number of the document bundle is odd, A control unit is provided for controlling so that the last page of the bundle is image-formed on one sheet at a position corresponding to the image forming position of the odd-numbered document on the sheet.

According to a second aspect of the present invention, the control means includes:
A timing delay unit for feeding a sheet corresponding to the last page of the document bundle to the image forming unit with a delay corresponding to the length of one document.

According to a third aspect of the present invention, the control means includes:
The last page of the document bundle is placed on the platen 2
The document feed timing adjusting means is placed so as to be placed at a distance corresponding to the length of one document from the reference line on the leading end side of the document.

[0017]

A plurality of originals are conveyed on the platen of the image forming apparatus from the lower side of the original conveying apparatus, two sheets at a time, and the originals are interchanged. Then, the two originals are image-formed on one sheet. At this time, the odd / even discrimination means discriminates whether the number of the document bundle is odd or even. If the number of the document bundle is an odd number, the control means is arranged so that the last page of the document bundle is image-formed at the position corresponding to the odd document on the sheet. Is controlled by

Thus, when forming an image in the parallel copy mode, an image can be formed without generating a blank page in a continuous page.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an image forming apparatus 13 as a copying machine.
0 and a side view of a longitudinal section of the circulating document feeder 110 placed on the platen 131.

The image forming apparatus 130 includes an optical system 132 for scanning image information of a document placed on a platen 131.
, An image forming unit 140, and a plurality of cassettes 146, 147, and the like accommodating the transfer sheet S. The original fed on the platen 131 as described later is
The platen 131 is placed so that one side edge thereof comes to the reference position 133 of the platen 131.

The movable mirror 135 moves to a position indicated by a broken line together with a lamp (not shown) to scan the original. Light reflected from the original passes through a movable mirror 135, a plurality of fixed mirrors 136, and a lens 137, and the photosensitive drum 141 of the image forming unit 140.
To form a latent image. The image forming unit 140 includes a well-known primary charger 142, a developing device 143, a cleaning device 145, and the like.

The transfer sheet S in the selected cassette (for example, 147) is fed by a feed roller 150 and is conveyed to registration rollers 153 by conveying rollers 151 and 152. The transfer sheet S fed at a predetermined timing by the registration roller 153 is
5, the toner image on the photosensitive drum 141 is transferred, and is transported to the fixing device 159 by the transport device 157 while being separated from the photosensitive drum 141 by the separation charger 156.
Transfer sheet S after fixing toner image by fixing device 159
Is discharged onto a discharge tray 161 by a discharge roller 160.

Next, the recirculating document feeder 110 will be described for each mode.

<Single-sheet copy mode> Reference numeral 105 denotes a document tray on which a plurality of documents P are placed;
106 is placed on the uppermost surface of the sheet material P, and
5 shows a document partition plate for partitioning the document P discharged onto the document 05. Document bundle P stacked on document tray 105
Is fed from the lowermost sheet (final page paper) by a feed roller 107, and is guided to a registration roller pair 112 while being separated one by one by a separation unit including a separation roller 109 and a separation belt 111.

The sheet P is abutted against the nip portion of the pair of registration rollers 112, performs registration, and is conveyed again. The driving roller 113 and the driven roller 115
And is guided to the conveyer belt 116 which rotates.
While the sheet P is held down by the platen 131 by the transport belt 116, the trailing edge of the document is moved to the reference position 133 (▽
Mark).

On the upstream side of the transport belt 116, a great circle reversing path including the pair of registration rollers 112, the reversing roller 117, and the transport roller 119 is provided. After the image is formed by the original P, the transport belt 116 rotates in the reverse direction, transports the original P by the reversing roller 117 and the transport roller 119, and discharges the original P onto the original tray 105 again by the discharge roller 120. On the other hand, when the last page is fed,
6 moves so as to be at the top of the discharged document, whereby the cycle end of the document bundle P is determined.

The above-described image forming operation is a one-sided copy mode for forming an image of image information of one side of the original P. When forming an image on both sides of the original P, the first side (front side) of the original P P is reversed by the reverse and reverse rollers 117 of the conveyance belt 116, the conveyance roller 119, and the pair of registration rollers 112, and is mounted again on the platen 131, and is formed on the document tray 105 after forming an image on the second surface (back surface). The paper is ejected.

<Parallel Copy Mode> FIG. 4 shows a flowchart of the parallel copy mode. In the parallel copy mode, two sheets from the lower side of the original bundle P are arranged in parallel on the platen,
This is to form an image of one original P on one transfer sheet S. First, the odd / even number of the number of originals P
Is determined.

(1) When the Number of Originals is Even When the number of originals is even, the last page (2n pages) is once fed onto the platen 131 in the same manner as in the one-sided copy mode of the one-sheet copy mode. Thereafter, the conveyance belt 116 rotates in the reverse direction to convey the document P to the reversing roller 117 and the conveyance roller 119, and the leading end (right end in FIG. 2) of the document P is positioned at the reference position 133 on the platen 131 (indicated by Δ in FIG. 1). ), Stop when it comes.

Next, the original P of 2n-1 pages is temporarily placed on the platen 131 in the same manner as in the one-sided copy mode. Here, the two originals are placed on the platen 131 with the right end (front end) of the 2n page and the left end (rear end) of the 2n-1 page, that is, adjacent edges being aligned at a predetermined interval.

Next, the conveyor belt 116 and the reversing roller 1
17, the two originals P are simultaneously conveyed to predetermined positions on the platen 131, and the left end (rear end) of the 2n page is set at the reference position 1
Both originals are stopped so as to reach 33 (see FIG. 2A). As shown in FIG. 2A, both originals P are
2, an image is formed by the image forming apparatus 130, and an image is formed on the first transfer sheet S as shown in FIG. 2B (however, the image is turned upside down) Is in a state of becoming).

Transfer sheet S after image formation by both originals
As shown in (b), the image of page 2n (even number page) is on the right side of transfer sheet S (even document corresponding position Se), and the image of page 2n-1 (odd number page) is on transfer sheet S. An image is formed on the left side of the sheet S (an odd document corresponding position So). Both originals after image formation are discharged onto the original tray 105 as in the single-sided mode. Hereinafter, similarly, image formation is performed up to the top document.

(2) When the number of originals is odd When the odd / even discriminating means 102 determines that the number of originals is odd, the last page (2 m
+1 page) in the same manner as in the one-sided copy mode.
Placed on top. Here, the main body registration roller pair 153
, The feeding of the transfer sheet S for the 2m + 1 page original is started up faster by the original size, so that the image formation start position on the transfer sheet S is delayed by the original size.

The control for delaying the image transfer timing to the transfer sheet S is controlled by a transfer timing delay means (not shown) in the control device 100.

FIG. 3A shows the relationship between the platen 131 and the original P placed thereon at this time, and FIG. 3B shows the state of the image formed on the transfer sheet S. FIG.
In (b), when the feeding operation of the main body registration roller pair 153 starts up quickly by the size of the document, the image is displayed on the left side of the transfer sheet S (corresponding to an odd document) as indicated by an arrow A (upper transfer sheet S). (At the position So side), image formation at an appropriate position is realized. If the main body registration roller pair 153 is started up at a normal timing, an image is formed on the right side of the transfer sheet S (the side of the even-numbered document corresponding position Se) as shown by an arrow B (lower side) and transferred. An inconvenient state occurs in which a blank page is left on the left side of the sheet S.

The 2m + 1 page original after image formation is discharged onto the original tray 105 in the same manner as in the single-sided copy mode.
After the discharge, two originals of the next 2m page and 2m + 1 page are image-formed in the same manner as in the above-mentioned even-number parallel copy mode. FIG. 4 shows a flowchart of the above-described parallel copy mode. When the number of originals is an even number in step S1 in FIG. 4, the process goes to steps S6 and thereafter, but 2m in S6 and S7 is 2n. 2m + 1 is 2n-
1 to be read (see FIG. 2).

Embodiment 2 As Embodiment 2 of the present invention, the parallel copy mode (at the time of an odd number of sheets) in the above embodiment is as follows.

The last page (2m + 1 page) is fed onto the platen 131 by the pair of registration rollers 112. At the time of this feeding, the 2m + 1 page original is placed on the platen 131 with a distance corresponding to the original size from the reference position 133. Is placed. In addition, the feeding timing of the transfer sheet S by the main body registration roller pair 153 at this time is performed at a normal timing.

As described above, the operation of placing the original P of the last page separated from the reference position 133 on the platen 131 by the size of the original is performed by an original feeding timing adjusting means (not shown) in the control device 100. Is controlled by

FIG. 5 shows the state of the original P on the platen 131 and the state of the image on the transfer sheet S after image formation. As shown in FIG. 5A, since the original P of 2m + 1 pages is placed on the platen 131 in a state in which it is advanced by the original size, the image formed on the transfer sheet S is
(B) As shown in the figure, it is formed at an appropriate position on the left side of the transfer sheet S (the side corresponding to the odd numbered document So) to prevent the generation of a blank page before the last page even in the odd numbered parallel copy mode. be able to.

<Another Example of Document Conveying Apparatus> FIG. 7 is a vertical sectional side view of a recirculating document conveying apparatus (RDF) 2, which is provided on an image forming apparatus 1 including a copying machine.

In FIG. 7, an RDF which is a document conveying device
The (circulation type document feeder of the present invention) 2 has a document tray 4 above, and a wide belt 7 wound around a driving roller 36 and a turn roller 37 is disposed below the document tray 4.
The wide belt 7 is in contact with the platen 3 of the copying machine main body 1, and conveys the sheet document P placed on the document tray 4 and places it at a predetermined position on the platen 3.
The sheet document P on the platen 3 is discharged onto the document tray 4.

Further, a pair of width direction regulating plates 33 are slidably arranged in the document tray 4 in the width direction of the sheet document P, and the width direction of the sheet document P placed on the document tray 4 is adjusted. Regulate the stability of the sheet original P during feeding,
The consistency at the time of discharging onto the document tray 4 is ensured. The width direction regulating plate 33 has a built-in jogging mechanism, which will be described later, and presses the sheet documents P discharged onto the document tray 4 one by one against the document reference guide 33 to further improve the consistency. . Further, the document tray 4 can be swung between an inclined position (FIG. 7) and a horizontal position (FIG. 8) about a swing center 40 by a document tray elevating mechanism described later.

Adjacent to the document tray 4, there is provided a half moon-shaped absorbing roller 5 and a stopper 21 which moves up and down by a stopper solenoid (not shown). Is restricted by the protruding stopper 21 so that it cannot advance downstream.

When copy conditions are input on the operation unit of the copying machine 1 and a start key (not shown) is pressed, the stopper 21 sinks down, the path of the sheet document P is opened, and the sheet document P is fed. The sheet is fed to the downstream by receiving the paper roller 5. At this time, the partition member 22 connected to a not-shown partition member motor built in the document reference guide 33 on the document tray rotates and rides on the uppermost sheet document P, and the unprocessed document and the processed document are rotated. And distinguish it.

Downstream of the stopper 21, there is provided a first separation unit including a transport roller 38 and a separation belt 6, which constitute a separation unit. The first separation unit rotates in the direction of the arrow and advances from the document tray 4. The sheet document P is separated one by one and transported further downstream.

A weight 20 is provided above the stopper 21 so that the number of sheet documents P on the document tray 4 is small and the sheet documents P are separated by the feeding force of the paper feed roller 5 alone. If the sheet document P cannot be advanced to
Is sandwiched between the sheet feeding roller 5 and the feeding force of the sheet feeding roller 5.

A document feed path (a), (b), (c) is formed from the separation sections 6, 38 to the platen 3, and the document feed paths (a), (b), (c) ) Is bent and connected to the conveyance path on the platen 3 to guide the sheet document P onto the platen 3. In the vicinity of the paper feed roller 5, an entrance sensor 23a, which is a transmission type optical sensor for detecting the presence or absence of a sheet original P placed on the original tray 4,
23b are arranged.

A large roller 1 is located on the left side of the main body of the RDF 2.
0, and the large roller 10
The document discharge paths (e) and (f) extend around the document tray 4 and extend above the document tray 4. Further, a document reversing path (e) for branching from the upper side of the large rollers 10 of the document discharge paths (e) and (f) and reversing the front and back of a double-sided document is provided. The downstream part of (e) merges with the document feeding path (b). On the downstream side of the document discharge path (f), a relay roller 44 and a discharge roller 11 are provided, and the document discharge paths (e) and (f) are provided.
Is discharged to the uppermost portion of the document bundle P on the document tray 4.

The sheet document P is conveyed and placed at a predetermined position on the platen 3 by the wide belt 7 disposed above the platen 3, and is discharged from the platen 3 after reading the image. A feeding roller 9 is provided at the junction of the document feeding paths (a), (b), and (c) and the document reversing path (e). A loop is formed in P to prevent skew of the sheet document P.
In the vicinity of the upstream of the feed roller 9, paper feed sensors 25a and 25b, which are transmission-type optical sensors for detecting the front end and the rear end of the sheet document P, are provided.
The sheet document P that has passed through any one of the transport paths (b) and (c) and the document reversing path (e) can be detected.

Downstream of the feed roller 9, registration sensors 39a and 39b, which are transmission type optical sensors for detecting the rear end of the sheet document P, are provided. Below the large roller 10 in the document discharge paths (e) and (f), reversing sensors 26a and 26b, which are transmissive optical sensors for detecting the sheet document P carried out from the platen 3, are arranged. Further, in the document discharge path (F) between the large roller 10 and the paper discharge roller 11, the passage of the sheet document P passing through the document discharge path (F) and discharged onto the document tray 4 is detected. Discharge sensors 27a and 27b, which are transmission type optical sensors, are provided.

A reversing flapper 34 for switching the path is provided at a portion branched from the document discharging paths (e) and (f) to the document reversing path (e). When the switch is turned off, the path is switched by swinging between the solid line position and the chain line position in the figure.

Further, on the right side of the main body of the RDF 2, a second document separating means for transporting a sheet document from the right end of the platen glass to an image reading portion on the platen 3, a second document feeding path (h), ( Li) and (nu).

The document tray 4 swings with the upper and lower positions shown in FIGS. 7 and 8 in conjunction with the later-described swinging operation of the document tray 4. As shown in FIG. 8, when the document tray 4 is at the lower limit position, a half-moon-shaped second paper feed roller 8 and a transport roller 15 and a separation belt 14 constituting a second separation section are arranged adjacent thereto. The document tray 4 rotates in the direction of the arrow.
The sheet originals P that have advanced from the sheet are separated one by one and conveyed further downstream.

The document tray 4 has an upper or lower limit depending on the size of the document placed on the tray and input conditions of the image forming apparatus. When the tray 4 reaches the lower limit position, the above-described stopper 21 of the tray 4 conveys the sheet document P placed on the tray 4 to the second separating means 14 and 15 for a certain distance. Tray 4
The stopper slide base 41 is rotated by the rotation of the eccentric cam 43 through the link 42 in the guide disposed in the
Move through. Eccentric cam 43 about support shaft 57
Has a flag 5 for detecting the home position.
3 and a transmission sensor 45 are provided.

When the document tray 4 reaches the lower limit position,
The sheet document stopper 19 swings upward about the support shaft 31 by the document stopper solenoid, and receives the sheet document P conveyed by the bundle conveying means. The sheet document P conveyed in a bundle is always transmitted through an optical sensor 28 of a transmission type that detects the presence or absence of a sheet document disposed near the upstream of the second separating means.
In steps a and b, the sheet is conveyed to a position where paper presence is detected. When the bundle conveyance is completed, the sheet document stopper 19 is configured to be placed on the sheet document P.

The second separation means 14, 15 is provided with a second
The second feeding roller 16 forms a loop on the reached sheet document P,
The skew of the sheet document P is prevented. In the vicinity of the upstream side of the second feed roller 16, a second paper feed sensor 3, which is a transmission type optical sensor for detecting the front end and the rear end of the sheet document P, is provided.
0a and 30b are provided. Further, a relay roller 17 is provided on the downstream side, and a transmission type optical sensor 18a for detecting the leading end position of the sheet document P is provided in the second feeding path (N).
1b is provided. The image sensor 18a, 18b
Controls the timing of a sheet material on which an image is formed in the image forming apparatus.

When the lowermost sheet is transported to the separation section by the rotation of the second transport roller 15, 1. Image forming apparatus 1
When the number of image forming copies is set to 1 by an input key, the sheet document stopper 19 remains mounted on the sheet document P, and the sheet document discharged by the discharge roller 11 is separated by the second separation. Regulate not to enter the department.

2. When the number of image forming copies is set to n by the input key in the image forming apparatus 1 (when one copy of the sheet document circulates n times); the sheet document stopper 19 moves upward until the sheet document circulates (n-1) times. When the first sheet document in the n-th cycle is reloaded on the document tray 4, the sheet document stopper 19 is placed on the sheet document, and the first sheet document is moved to the second separation section. Regulate entry. At the end of n circulation, the leading end of the sheet document P is regulated by the sheet document stopper 19. afterwards,
The document tray 4 moves upward and stops at the upper limit position.

Next, the parallel copy mode of the circulating document feeder will be described.

At the time of parallel copying, the original P is stacked on the original tray 4 in a face-up state, the parallel copying mode is set by a mode input key (not shown) of the image forming apparatus 1, and the copy of the image forming apparatus 1 is started. When the document tray 4 is turned on, the document tray 4 rotates clockwise about the pivot shaft 40 to the position shown in FIG. 8, and the document P is moved on the document tray 4 by the stopper 21 to the second separating means 14 and 15. The bundle is conveyed to the side (FIG. 9).

After the original P is conveyed in a bundle, the originals are sequentially separated one by one from the lowermost sheet by the second separating means 14 and 15, and the second sheet is moved to the second feeding path (h, l, n) side. Feed roller 16,
It is transported via the transport roller 17. FIG. 10, FIG.
As shown in FIG. 1, the original m (mth page) is
As shown in (a), the sheet is conveyed after the tip thereof abuts against the second feeding roller 16 to correct skew.

When the trailing edge of the document P passes through the sensor 30, the drive control of the second feeding roller 16 is controlled so that the trailing edge of the document m is located immediately after the nip of the second feeding roller 16. This is performed by the control device 90 (FIG. 10B).

Next, the original (m-1) is separated by the second separating means 14 and 15, and the leading end of the original (m-1) abuts on the second feed roller 16 after passing through the sensor 30. Then, skew correction is performed here (FIG. 10C).

Next, the second separating means 14 and 15, the second feeding roller 16 and the conveying roller 17 are connected to a drive source by a clutch (not shown), and start rotating at the same peripheral speed, and (M-1) is transported simultaneously. Manuscript m, (m-
1) is conveyed from the other end 3B of the platen glass 3 via the wide belt 7 and the original m is placed on the left side in the figure, and the original (m-
With 1) on the right, the two originals m and (m-1) are arranged in parallel on the platen glass 3 (FIG. 11E).

Thereafter, the reading section 1A of the image forming apparatus 1
Moves from one end 3A of the platen glass 3 to the other end 3B, and reads two images to create a copy sheet S as shown in FIG. After the image reading is completed, the two originals m and (m-1) are continuously fed to the original discharge paths (e and f).
And is discharged onto the document tray 4 by the discharge roller 11 via the By repeating the above operation a required number of times, the parallel copy mode can be implemented.

The distance (inter-page distance) between the trailing edge of the document m and the leading edge of the document (m-1) is adjusted by arbitrarily setting the stop position of the document m after passing through the sensor 30. It is possible.

In this embodiment, the second feeding roller 1
Although the interpage distance was adjusted in six copies, any roller (for example, the transport roller 17) can be used depending on the driving method of each roller, the sensor arrangement method, and the like.

As described above, at the time of setting the parallel copy mode, it is possible to exchange documents at high speed by the circulation type document transport device of the document face-up type, and to copy the inner copy paper out of page order. Can be efficiently provided to the user.

[0071]

According to the present invention, in the parallel copy mode in which image information of two documents is formed on one sheet, the last page when the number of document bundles is an odd number is at the position corresponding to the odd number of sheets. By controlling so that an image is formed, the parallel copy mode can be realized without creating a blank page in a continuous page of the sheet after the image formation.

[Brief description of the drawings]

FIG. 1 is a vertical side view of an image forming apparatus according to an embodiment of the present invention.

FIG. 2A is a plan view showing the state of the original and the platen when the original bundle in the parallel copy mode is an even number, and FIG.
The figure is a plan view showing the image state of the transfer sheet.

FIG. 3A is a plan view showing the state of the original and the platen when the number of originals in the parallel copy mode is an odd number, and FIG.
The figure is a plan view showing the image state of the transfer sheet.

FIG. 4 is a flowchart of an image forming operation in the parallel copy mode.

FIG. 5 is a plan view showing a state of a document and a platen, and a state of a transfer sheet S and an image according to a second embodiment of the present invention.

FIG. 6 is a flowchart of an image forming operation in the parallel copy mode.

FIG. 7 is a longitudinal sectional side view of a ring-shaped document conveying device as another document conveying device.

FIG. 8 is an operation diagram of a document tray and a document in the parallel copy mode.

FIG. 9 is an operation diagram of a document tray and a document in the parallel copy mode.

FIG. 10 is a sheet feeding operation diagram.

FIG. 11 is a sheet feeding operation diagram.

FIG. 12 is a vertical sectional side view showing a first example of a conventional document feeder.

FIG. 13 is a plan view of a document arrangement on a platen glass and a copy sheet.

FIG. 14 is a vertical sectional side view showing a second example of a conventional document feeder.

FIG. 15 is a plan view of a document arrangement on a platen glass and a copy sheet.

FIG. 16 is a vertical sectional side view showing a third example of a conventional document feeder.

FIG. 17 is an operation diagram showing a document arrangement on a platen glass in the same manner.

[Explanation of symbols]

 P Document (sheet document) S Transfer sheet (copy paper) (A, B) First feed path (H, L, N) Second feed path (E, F) Document discharge path 1 Image forming apparatus 1A Image reading unit 2 Circulating original transport device 3 Platen glass 3A One end of platen glass 3B The other end of platen glass 4 Document tray 6,38 First separating means 14,15 Second separating means So Odd document corresponding position Se Even document corresponding position 100 Controller 101 Parallel copying means 102 Odd / even discriminating means 110 Automatic document feeder 130 Image forming apparatus 131 Platen glass

Continuation of the front page (72) Inventor Tomohito Nakagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-4-356066 (JP, A) JP-A-4-313772 ( JP, A) JP-A-5-6048 (JP, A) JP-A-5-19562 (JP, A) JP-A-62-83744 (JP, A) JP-A-63-165841 (JP, A) JP-A-63-92533 (JP, A) JP-A-63-285557 (JP, A) JP-A-4-56872 (JP, A) JP-A-1-303456 (JP, A) JP-A-62-55667 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 G03G 21/00

Claims (3)

(57) [Claims] 1. A document conveying apparatus comprising: a document conveying device for conveying a plurality of document bundles two sheets at a time from the lower side thereof and reversing the order of preceding and succeeding originals on a platen of an image forming apparatus; An image forming apparatus comprising a copying unit, wherein two even-numbered and odd-numbered originals placed in parallel on the platen are image-formed on one sheet, wherein the total number of the original bundle is an odd number. In the case of (1), there is provided control means for controlling so that the last page of the document bundle is image-formed on one sheet at a position corresponding to the image forming position of the odd-numbered document on the sheet. Image forming apparatus. 2. The timing delay means for feeding a sheet corresponding to the last page of the bundle of originals to an image forming unit with a delay corresponding to the length of one original. The image forming apparatus according to claim 1. 3. The control unit according to claim 1, wherein the last page of the bundle of originals is moved by an amount corresponding to a length corresponding to one original from a leading end side reference line of two originals placed on the platen. The image forming apparatus according to claim 1, wherein the image forming apparatus is a document feeding timing adjusting unit that is placed separately.