JPH11143138A - Both-side image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity in forming images on the both surfaces of plural transfer materials by forming the images on the surfaces of plural other transfer materials, during a time from image formation on the front surface to that on the rear surface. SOLUTION: The first - third transfer materials P1-P3 among first - fourth transfer materials P1-P4 carried from a paper feeding system D are carried to a photoreceptor C. The first - third transfer materials P1-P3 are successively transferred on the front surfaces by the photoreceptor C, carried to an ejection and reverse both-side system and turned upside down after the paths are selected. Then, the first transfer material P1 is carried to the photoreceptor C as it is and is transferred onto the rear surface and then, ejected outside a device. Thus, in the both-side image forming device for forming the images on the front surfaces of the other transfer materials, during a time from the image formation on the front surface to the image formation on the rear surface in the first sheet of the transfer material, since the other transfer materials are two or more, the productivity of the image formation on the both surfaces of the plural transfer materials can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic double-sided image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, image data is stored as a double-sided image forming apparatus of this type, and based on the stored image data, an image is formed between the image formation on the front surface of the first transfer material and the image formation on the back surface. A double-sided image forming apparatus for forming an image on the surface of another transfer material is known.

[0003]

The above-described double-sided image forming apparatus has a problem that productivity of double-sided image formation of a plurality of transfer materials is low.

Accordingly, an object of the present invention is to provide a double-sided image forming apparatus capable of solving the above-mentioned problems of the conventional double-sided image forming apparatus and improving the productivity of double-sided image forming of a plurality of transfer materials. To offer.

[0005]

According to the present invention, in order to achieve the above object, the invention according to claim 1 stores image data, and stores one image based on the stored image data. In a double-sided image forming apparatus that forms an image on the front surface of another transfer material between the image formation on the front surface and the image formation on the back surface of the first transfer material, the number of the other transfer materials is two or more. A double-sided image forming apparatus characterized by the above-mentioned.

According to a second aspect of the present invention, image data is stored, and another image data is stored between the image formation on the front surface and the image formation on the back surface of the first transfer material based on the stored image data. In the double-sided image forming apparatus for forming an image on the surface of a transfer material, the number of the other transfer materials is changed according to the size of the transfer material.

According to a third aspect of the present invention, image data is stored, and based on the stored image data, another image data is transferred between the image formation on the front surface and the image formation on the back surface of the first transfer material. In the double-sided image forming apparatus for forming an image on the surface of a transfer material, the number of the other transfer materials is changed depending on the time until the image data is transferred.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in the drawings, in FIG. 1, a writing system B writes image data read by a reading system A on a photosensitive member C to form a latent image. This latent image is formed into a visible image by toner by the developing system. Then, this visible image is transferred by the photoconductor C onto the transfer material P conveyed from the paper feeding system D, and the transfer material P is discharged, inverted, and conveyed to the double-sided system F.

Further, this embodiment has an operation program (not shown) including an operation program in which the operation procedure of each member corresponding to the image data stored in the storage unit is incorporated, and an operation unit for operating each unit by the operation program. Control means is provided.

FIG. 2 shows the details of the discharging, reversing, and double-sided system F. In this embodiment, the image forming is started, and the transfer material P conveyed from the paper feeding system D is transferred to the photosensitive members C, When the image is fixed by the fixing system E and the path I is selected after passing through the fixing system E, the branch claw 3 is switched to the dotted line position, and is discharged out of the apparatus as it is as indicated by the solid arrow I.

Next, when the paths II and III are respectively selected, the branch claw 3 is switched to the position indicated by the solid line. Then, the transfer material P advances between the first guide plates 2 and 4 and the second guide plates 5 and 11 and temporarily stops on the transport guide plate 10 as indicated by solid arrows II and III. Then, after traveling in the opposite direction and being reversed, when the route II is selected, the vehicle travels along the first guide plate 4 as indicated by the dotted arrow II, and when the route III is selected, the transport guide plate 10 is selected. And between the upper and lower guide plates 15 and 16 provided between the sheet feeding system D and the sheet feeding system D.

A detection sensor 6 is provided on the second guide plate 5, and a reversing roller 7 which rotates in the direction of the arrow above and below the second guide plate 5, and is urged upward. Inverted branch claws 23 are provided, which are nested with each other. When the transfer material P enters between them, the transfer material P is pressed against the reversing roller 7 by the reversing branch claw 23 and advances between them.

When the transfer material P that has proceeded as described above once stops on the transport guide plate 10, it can be widened and narrowed in the vertical direction with respect to FIG. Moves back and forth toward the narrow position, and the transfer material P
The position of both sides of the. During the transfer of the transfer material P as described above, the reverse drive roller 8 provided to be able to move up and down moves downward from the solid line position to the chain line position according to the detection information of the detection sensor 6 which has detected the rear end. The transfer material P is conveyed on the conveyance guide plate 10 in the reverse direction as indicated by dotted arrows II and III. In this way, when the transfer material P traveling in the reverse direction is sandwiched between the two-side drive roller 13 and the two-side driven roller 12, the reverse rotation drive roller 8
Returns to the upper position, and the side fence 30 also returns to the wide position.

When the path II is selected, the double-sided branching pawls 14 located on the front surfaces of the rollers 12 and 13 are switched to the positions indicated by the dotted lines, and the transfer material P is transferred to the first guide plate 4 as shown by the solid arrow II. Proceed along.

On the other hand, when the path III is selected, the double-sided branching pawl 14 is switched to the solid line position, and the transfer material P is moved to the upper guide plate.
Between the lower guide plate 16 and the lower guide plate 16 by driving rollers 17, 19;
Proceed as shown in I. The driving rollers 17 and 19 are constituted by interlocking driving rollers, one of which is provided with a clutch, and the driving roller 21 is provided with a clutch.
19; 21 stop or start. A transport detection sensor 2 is provided between the rollers 17 and 19;
0 and 22 are provided.

Driving roller 21 and driven roller opposed thereto
The transfer material P having passed through the transfer roller 18 is guided by guide plates 15, 24; 25 and 26, and is conveyed to the photoconductor C by conveyance rollers 27 and registration rollers 28. The guide plate 26 is provided with a pre-registration sensor 29. ing.

FIG. 3 shows a procedure for forming images on the front and back surfaces of a plurality of transfer materials P1 to P6 (six in total, four front and back transfer in this embodiment) according to the embodiment of the present invention. 4 to 7 show the operation state at that time. In this case, the image data read by the reading system A in advance is stored in the storage unit of the apparatus main body. Here, of the first to fourth transfer materials P1 to P4 conveyed from the paper feeding system D, the first
The third transfer material P1 to P3 are conveyed to the photosensitive member C as shown in FIG.
It is located between and stopped.

[0018]

Embodiment 1 [Surface Transfer of First to Third Transfer Materials P1 to P3] Then, as shown in FIG.
P3 is sequentially transferred to the surface by the photoconductor C,
The sheet is discharged, inverted, and conveyed to the double-sided system F (S1 to S in FIG.
3), the path III is selected and inverted.

[Back Transfer of First Transfer Material P1] And FIG.
As shown in (1), the first transfer material P1 is conveyed as it is to the photoreceptor C, transferred to the back surface, discharged, inverted, conveyed to the double-sided system F, and the path I is selected and discharged out of the apparatus. (S4 in FIG. 3).

On the other hand, the leading end of the second transfer material P2 is detected by the conveyance detecting sensor 22, and the leading end of the third transfer material P3 is detected by the carrying detection sensor 20. , 19, lower guide plate respectively
16, the fourth transfer material P4 is still stopped.

[Surface Transfer of Fourth Transfer Material P5] In this case, when the trailing end of the first transfer material P1 is detected by the pre-registration sensor 29, the transport of the fourth transfer material P4 stopped as shown in FIG. Is started, is conveyed to the photoreceptor C, is transferred to the surface thereof, and is discharged, turned over, conveyed to the double-sided system F, and the path III
Is selected and inverted (S5 in FIG. 3).

[Back Transfer of Second Transfer Material P2] In this case, when the rear end of the fourth transfer material P4 is detected by the pre-registration sensor 29, as shown in FIG. 5, the stopped second transfer material P2 is conveyed. Is started, and as shown in FIG. 6, the sheet is conveyed to the photoreceptor C, transferred to the rear surface thereof, discharged, inverted, conveyed to the double-sided system F, and the path I is selected and discharged out of the apparatus ( S6 in FIG. 3).

After the transfer of the second transfer material P2 is started, the transfer of the third transfer material P3 is also started, and the leading end thereof is detected by the transfer detection sensor 22 and stopped by the drive roller 21. 5th
The leading end of the transfer material P5 is located between the guide plates 24 and stopped.

[Surface Transfer of Fifth Transfer Material P5] At this time, when the trailing end of the second transfer material P2 is detected by the pre-registration sensor 29, the stopped transfer of the fifth transfer material P5 is started, and the photosensitive member is started. C, transferred to the surface, discharged,
The sheet is conveyed to the reversing and double-sided system F, and the path III is selected and reversed (S7 in FIG. 3).

[Transfer of Back Side of Third Transfer Material P3] In this case, when the rear end of the fifth transfer material P5 is detected by the pre-registration sensor 29, the third transfer material P stopped on the lower guide plate 16 is detected.
3 is started, is conveyed to the photoconductor C, is transferred to the back surface thereof, is discharged, inverted, is conveyed to the double-sided system F, and the path I is selected and discharged out of the apparatus (S8 in FIG. 3). ).

[Surface Transfer of Sixth Transfer Material P6] In this case, when the rear end of the third transfer material P3 is detected by the pre-registration sensor 29, the conveyance of the stopped sixth transfer material P6 is started, and the photosensitive member is started. C, transferred to the surface, discharged,
The sheet is conveyed to the reversing and double-sided system F, and the path III is selected and reversed (S9 in FIG. 3).

[Transfer of Back Surface of Fourth Transfer Material P4] In this case, when the rear end of the sixth transfer material P6 is detected by the pre-registration sensor 29, the conveyance of the stopped fourth transfer material P4 is started, and the photosensitive member is started. C, transferred to the back side, discharged,
The sheet is conveyed to the reversing and double-sided system F, and the path I is selected and discharged out of the apparatus (S10 in FIG. 3).

[0028]

[Embodiment 2] FIG. 8 shows a first embodiment of the present invention in which five first transfer papers are used when transfer papers of a certain size or more are applied.
2 to 5 show a second embodiment having a procedure in which images are formed on both front and back surfaces of transfer materials P1 to P5, and FIGS. 9 to 12 show operating states at that time.

In this case, the image data read by the reading system A in advance is stored in the storage section of the apparatus main body.
Here, the first and second transfer materials P1 and P2 conveyed from the paper feeding system D
9 is conveyed to the photoreceptor C as shown in FIG.

[Surface Transfer of First and Second Transfer Materials P1 and P2]
The first and second transfer materials P1 and P2 conveyed from the paper feeding system D are shown in FIG.
Are transferred to the photoconductor C as shown in FIG. 9 and sequentially transferred to the surface thereof by the photoconductor C as shown in FIG.
The sheet is discharged, turned over, and transported to the duplex system F, where the path III is selected and turned upside down (S1, S2 in FIG. 3).

[Back Transfer of First Transfer Material P1] And FIG.
As shown in (1), the first transfer material P1 is conveyed as it is to the photoreceptor C, transferred to the back surface, discharged, inverted, conveyed to the double-sided system F, and the path I is selected and discharged out of the apparatus. (S3 in FIG. 3).

On the other hand, the tip of the second transfer material P2 is a sensor.
The third transfer material P3 is stopped on the lower guide plate 16 by the drive roller 21 after being detected by the drive roller 21, and the leading end of the third transfer material P3 is stopped between the guide plates 24.

[Surface Transfer of Third Transfer Material P3] In this case, when the trailing end of the first transfer material P1 is detected by the pre-registration sensor 29, the conveyance of the third transfer material P3 stopped as shown in FIG. Is started, is conveyed to the photoreceptor C, is transferred to the surface thereof, and is discharged, turned over, conveyed to the double-sided system F, and the path III
Is selected and inverted (S4 in FIG. 3).

[Transfer of Back Side of Second Transfer Material P2] When the rear end of the third transfer material P3 is detected by the pre-registration sensor 29 at this time, the conveyance of the stopped second transfer material P2 is started.
As shown in FIG. 11, after being conveyed to the photoreceptor C and transferred to the back surface thereof, discharged, reversed, conveyed to the double-sided system F, the path I
Is selected and discharged out of the apparatus (S5 in FIG. 3).

After the transfer of the second transfer material P2 is started, the transfer of the third transfer material P3 is also started, and the leading end thereof is detected by the sensor 22 and stopped by the drive roller 21. On the other hand, the fifth transfer material P
5 is stopped with its tip located between the guide plates 24.

[Surface Transfer of Fourth Transfer Material P4] When the trailing end of the second transfer material P2 is detected by the pre-registration sensor 29 at the time described above, as shown in FIG. Conveyance is started, conveyed to the photoreceptor C, transferred to the surface thereof, discharged, reversed, conveyed to the double-sided system F, and route II
I is selected and inverted (S6 in FIG. 3).

[Transfer of Back Side of Third Transfer Material P3] In this case, when the rear end of the fourth transfer material P4 is detected by the pre-registration sensor 29, the third transfer material P stopped on the lower guide plate 16 is stopped.
Then, as shown in FIG. 12, the sheet is conveyed to the photoreceptor C, transferred to the back surface thereof, discharged, inverted, conveyed to the double-sided system F, and the path I is selected and discharged out of the apparatus. (S7 in FIG. 3).

[Surface Transfer of Fifth Transfer Material P5] When the trailing end of the third transfer material P3 is detected by the pre-registration sensor 29 at this time, the stopped transfer of the fifth transfer material P5 is started, and the photosensitive member is started. C, transferred to the surface, discharged,
The sheet is conveyed to the reversing and double-sided system F, and the path III is selected and reversed (S8 in FIG. 3).

When the rear end of the fifth transfer material P5 is detected by the pre-registration sensor 29 at this time, the conveyance of the stopped fourth transfer material P4 is started, and the photosensitive member is transferred. C, transferred to the back side, discharged,
The sheet is conveyed to the reversing and double-sided system F, and the path I is selected and discharged out of the apparatus (S9 in FIG. 3).

In this embodiment, as described above, when the transfer material has a predetermined size or more, the surface transfer of the second transfer material is performed between the front transfer and the back transfer of the first transfer material. Will be performed.

[0041]

Third Embodiment FIGS. 13 to 16 are applied to the case where the time until the image data stored in the storage unit is developed and written in the writing system B is longer than a predetermined time in the first embodiment. Three first to third transfer materials P1 to P3 in the case
3 shows an operation state of the third embodiment having a procedure of forming an image on both the front and back surfaces.

In this case, the first and second transfer materials P1 and P2 conveyed from the paper feeding system D are conveyed to the photosensitive member C as shown in FIG. It is located between the plates 24 and stopped.

[Surface Transfer of First and Second Transfer Materials P1 and P2]
The first and second transfer materials P1 and P2 conveyed as described above are shown in FIG.
As shown in FIG. 13, the image is sequentially transferred to the surface by the photoconductor C, and then discharged, inverted, transported to the double-sided system F, and the path II
I is selected and inverted.

Here, the tip of the first transfer material P1 is detected by the sensor 22 and detected by the drive roller 21, and the tip of the second transfer material P2 is detected by the sensor 20 and the drive roller 21 detects the drive roller.
As shown in FIG. 14, the motors 17 and 19 are stopped on the lower guide plate 16, respectively.

[Back surface transfer of first transfer material P1] Here, when a data write command is issued, the drive rollers 21, 17 and 19 are sequentially operated to leave the first transfer material P1 as shown in FIG. After being conveyed to the photoreceptor C and transferred to the back surface, discharged, inverted, conveyed to the duplex system F, the path I is selected and discharged out of the apparatus, and the second transfer material P2 is the first transfer material before the transfer. It moves to the position of P1 and stops.

[Surface Transfer of Third Transfer Material P3] In this case, when the trailing end of the first transfer material P1 is detected by the pre-registration sensor 29, the conveyance of the stopped third transfer material P3 is started, and the photosensitive member is started. C, transferred to the surface, discharged,
Inverted, transported to the double-sided system F, and the route III is selected.
As shown in (2), at the rear of the second transfer material P2, it moves to the position of the second transfer material P2 before transport and stops. After that the second
The image is transferred to the subsequent transfer material in the same order as in the embodiment.

In this embodiment, as described above, if the time from developing and writing the image data is equal to or longer than a predetermined time, the time between the front transfer and the back transfer of the first transfer material is
The surface transfer of the second transfer material is performed.

[0048]

The present invention is as described above. According to the first aspect of the present invention, image data is stored, and an image of the surface of the first transfer material is stored based on the stored image data. In a double-sided image forming apparatus that forms an image on the front surface of another transfer material between the formation and the image formation on the back surface, the other transfer material is two or more. There is an effect that the productivity of image formation can be improved.

According to a second aspect of the present invention, image data is stored, and another image data is stored between the image formation on the front surface and the image formation on the back surface of the first transfer material based on the stored image data. In the double-sided image forming apparatus for forming an image on the surface of a transfer material, the number of the other transfer materials is changed according to the size of the transfer material. Since the front transfer of the second transfer material is performed between the front transfer and the back transfer of the first transfer material, the following transfer material collides with the preceding transfer material during double-sided image formation. This has the effect of avoiding the occurrence of.

According to a third aspect of the present invention, image data is stored, and based on the stored image data, another image is formed between the image formation on the front surface and the image formation on the back surface of the first transfer material. In the double-sided image forming apparatus for forming an image on the surface of the transfer material, the number of the other transfer materials is changed depending on the time until the transfer of the image data, and the image data is developed. If the time until writing is equal to or longer than a predetermined time, the surface transfer of the second transfer material is performed between the front transfer and the back transfer of the first transfer material. This has the effect of avoiding the problem that the subsequent transfer material collides with the next transfer material.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the present invention.

FIG. 2 is an enlarged front view of a main part of the above.

FIG. 3 is an operation procedure diagram of the first embodiment.

FIG. 4 is an operation explanatory view of an initial step of the embodiment.

FIG. 5 is an operation explanatory view of a subsequent step of the above.

FIG. 6 is an operation explanatory view of the next succeeding step of the above.

FIG. 7 is an operation explanatory view of the next succeeding step of the above.

FIG. 8 is an operation procedure diagram of the second embodiment.

FIG. 9 is an operation explanatory view of an initial step of the embodiment.

FIG. 10 is an operation explanatory view of a subsequent step of the above.

FIG. 11 is an operation explanatory view of the next succeeding step of the above.

FIG. 12 is an operation explanatory view of the next succeeding step of the above.

FIG. 13 is an operation explanatory view of an initial step of Embodiment 3 of the present invention.

FIG. 14 is an operation explanatory view of a subsequent step of the above.

FIG. 15 is an operation explanatory view of the next succeeding step of the above.

FIG. 16 is an operation explanatory view of the next succeeding step of the above.

[Explanation of symbols]

Reference Signs List A reading system B writing system C photoreceptor D paper feeding system E fixing system F discharging, reversing, double-sided system 2 first guide plate 3 branch claw 4 first guide plate 5 second guide plate 6 detection sensor 7 reversing roller 8 reverse rotation Drive roller 9 Reverse rotation driven roller 10 Conveyance guide plate 11 Second guide plate 12 Double-sided driven roller 13 Double-sided drive roller 14 Double-sided branch claw 15 Upper guide plate 16 Lower guide plate 17 Drive roller 18 Drive roller 19 Drive roller 20 Transport detection sensor 21 Drive Roller 22 Transport sensor 23 Reverse branch claw 24 Guide plate 25 Guide plate 26 Guide plate 27 Transport roller 28 Registration roller 29 Pre-registration sensor

Claims (3)

[Claims] 1. An image processing method for storing image data on a front surface of another transfer material during a period from the image formation on the front surface of the first transfer material to the image formation on the back surface based on the stored image data. In the double-sided image forming apparatus for forming, the other transfer material comprises two or more sheets. 2. A method for storing image data on a front surface of another transfer material during a period from the image formation on the front surface of the first transfer material to the image formation on the back surface based on the stored image data. In the double-sided image forming apparatus for forming, the number of the other transfer materials is changed according to the size of the transfer material. 3. An image on the front surface of another transfer material between image formation on the front surface of the first transfer material and image formation on the back surface based on the stored image data. In the double-sided image forming apparatus for forming, the number of the other transfer materials is changed according to the time until the transfer of the image data.