JPH10186737A - Double-side image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable images to be formed on second and first sides at desired time intervals by adjusting the timing of synchronizing three operations, i.e., formation of a toner image transferred onto a toner image receiver as a second- side image, formation of a toner image on a photoreceptor drum as a first-side image, and the feed of transfer paper. SOLUTION: Paper feed means feed transfer paper P from a paper feed cassette, sends it out using a feed roller, and conveys it to a feed timing roller. Drive means drive a photoreceptor drum 10 and a toner image receiver. Synchronization means synchronize the paper feed means with the drive means. At a resist control part 31 serving as the synchronization means, three operations, i.e., the operation of the photoreceptor drum 10, the operation of brining the toner image receiver into contact with the photoreceptor drum, and the operation of starting the transfer paper P, are synchronized. At a timing control part 32, formation of an image on a first side is controlled, and information is sent to an image write control part 40. A transfer paper feed control part 33 controls a paper motor 15d. The control part 30 controls execution of image formation on both sides through synchronization achieved by the synchronization means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to double-sided image forming in which a charging unit, a writing unit and a developing unit are arranged around a photosensitive drum to transfer and fix a toner image formed on the photosensitive drum onto transfer paper. Related to the device.

[0002]

2. Description of the Related Art Conventionally, in a double-sided image forming apparatus, an image on a first side formed on a photosensitive drum is transferred and fixed on a transfer sheet, and temporarily stored in a double-sided reversing sheet feeder. The transfer paper is fed from the double-sided reversing paper feeder again in synchronization with the image formed on the photosensitive drum, and the image on the second side is transferred and fixed on the transfer paper.

This double-sided image forming apparatus is, as described above,
Since the transfer of the transfer sheet is performed such as feeding the sheet to the two-sided reversing sheet feeder and passing the sheet twice through the fixing device, the reliability of transfer sheet transfer is low, which causes a jam or the like. In contrast, JP-B-49-37538 and JP-B-54-2
JP-A-8740, JP-A-1-44457 and JP-A-4-214576 disclose a method in which a toner image is formed on both sides of a transfer sheet and then fixed once.

[0004]

However, in a double-sided image forming apparatus for forming a double-sided image using the double-sided reversing sheet feeding apparatus, as is well known, the transfer distance of the transfer paper is long, so that much processing time is required for copying. And the transfer paper is heated twice to fix the image on the transfer paper. Therefore, the inventor of the present invention provided the two image bearing units and the two transfer units in advance to transfer the toner image to both surfaces (the first and second surfaces) of the transfer paper.
A study was conducted on an apparatus that simultaneously fixes transfer paper having toner images on both sides, and it was possible to realize a two-sided image forming apparatus capable of simultaneously performing two-sided copying.

However, as a further problem, a two-sided image forming apparatus (printer) for forming an image by inputting external image information is required to print a color image or a high-definition monochrome image having a very large amount of image information to be printed. It takes time to develop dots in the memory in the printer, which is an obstacle to improving the printer speed. On the front and back sides, there is a problem in matching the processing time in the image processing unit in the computer with the timing of the printing operation on the front and back sides. Further, in a double-sided image forming apparatus (copier) having an image reading unit, when the automatic document feeder is not provided, the reversal of the front side and the back side must be performed manually, which causes a time interval. There is.

Accordingly, an object of the present invention is to provide a two-sided image forming apparatus, comprising: a toner image transferred to a toner image receiver as a two-sided image; a toner image formed on a photosensitive drum as a first-sided image; It is another object of the present invention to provide a double-sided image forming apparatus which can improve the way of setting three synchronous timings of sheet feeding and can form images on the second side and the first side at arbitrary time intervals. Another object of the present invention is to provide a double-sided image forming apparatus according to the above-described double-sided image forming apparatus, wherein a jam processing mechanism of the transfer sheet is easily processed when a paper jam occurs during copying. Is to provide.

[0007]

The above object is achieved by the following means. That is, (1) a toner image forming means including a photosensitive drum, a toner image receiving body which is an intermediate transfer body of the toner image, and a toner image formed on the photosensitive drum is transferred to the toner image receiving body, or First transfer means for transferring the toner image to the first surface of the transfer paper; second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper;
An image memory for storing image information, writing means for writing to the photosensitive drum based on the image information in the image memory, and a toner image forming timing detecting means for detecting a toner image forming timing or detecting a toner image on the photosensitive drum A toner image detector that detects a toner image on the toner image receiver, a toner image formation timing detector or the toner image detector, and a toner image receiver detector that detects the toner image on the toner image receiver. Paper feeding means for feeding transfer paper, driving means for driving the photosensitive drum and the toner image receiving body, synchronizing means for synchronizing the paper feeding means and the driving means, An image instructing unit, and a control unit for controlling execution of double-sided image formation, wherein after forming the first side of the document on the photosensitive drum, the photosensitive drum is After transferring the toner image to the toner image receiving member from, the photosensitive drum stops rotating, the toner image receiving member is separated from the photosensitive drum, the rotation is continued, and an instruction signal from the instruction means is provided. The synchronous unit synchronizes the photosensitive drum, the toner image receiver, and the paper feed unit for forming an image on the second side, and the control unit forms a double-sided image. Double-sided image forming device.

(2) Toner image forming means including a photosensitive drum, a toner image receiving member as an intermediate transfer member of the toner image,
A first transfer unit that transfers the toner image formed on the photosensitive drum to the toner image receiver or transfers the toner image to the first surface of a transfer sheet; and a first transfer unit that transfers the toner image transferred to the toner image receiver. A second transfer unit for transferring the image to the second side of the transfer sheet; an image memory for storing image information; a writing unit for writing to the photosensitive drum based on the image information in the image memory; Toner image forming timing detecting means for detecting or a toner image detecting means for detecting a toner image on a photosensitive drum; toner image receiving body detecting means for detecting a toner image on the toner image receiving body; and toner image forming timing detecting Means or a toner image detecting means, paper feeding means for feeding a transfer sheet based on the information of the toner image receiver detecting means, the photosensitive drum and the toner image receiving means. A driving unit for driving a body, a synchronizing unit for synchronizing the paper feeding unit and the driving unit, an instruction unit for instructing image formation on a second surface, and a control unit for controlling execution of double-sided image formation, After forming an image of the first side of the document on the photoconductor drum, transferring the toner image from the photoconductor drum to the toner image receiver, the photoconductor drum continues to rotate, and the toner image receiver is The photoconductor drum, the toner image receiver, and the paper feeding unit for forming an image on the second surface by the synchronizing unit in accordance with an instruction signal from the instruction unit, while separating from the body drum and continuing rotation. Wherein a double-sided image is formed by the control unit.

(3) Toner image forming means including a photosensitive drum, a toner image receiving member as an intermediate transfer member of the toner image,
A first transfer unit that transfers the toner image formed on the photosensitive drum to the toner image receiver or transfers the toner image to the first surface of a transfer sheet; and a first transfer unit that transfers the toner image transferred to the toner image receiver. A second transfer unit for transferring the image to the second side of the transfer sheet; an image memory for storing image information; a writing unit for writing to the photosensitive drum based on the image information in the image memory; Toner image forming timing detecting means for detecting or a toner image detecting means for detecting a toner image on a photosensitive drum; toner image receiving body detecting means for detecting a toner image on the toner image receiving body; and toner image forming timing detecting Means for feeding a transfer sheet based on information of the toner image detecting means and the toner image receiver detecting means, the photosensitive drum and the toner image receiving means A driving unit that drives the sheet feeding unit, a synchronizing unit that synchronizes the driving unit with the paper feeding unit, an instruction unit that instructs image formation on a second surface, and a control unit that controls execution of double-sided image formation. After forming an image of the first side of the document on the photoconductor drum, transferring the toner image from the photoconductor drum to the toner image receiver, the photoconductor drum stops rotating, and the toner image receiver receives the photoconductor drum. The photosensitive drum, the toner image receiver, and the sheet feeding unit for forming an image on the second side are formed by the synchronizing unit in response to an instruction signal from the instruction unit, while separating from the drum and stopping the rotation. A two-sided image forming apparatus, wherein two-sided image formation is performed by the control unit in synchronization.

(4) A toner image forming means including a photosensitive drum, a toner image receiving member as an intermediate transfer member of the toner image,
A first transfer unit that transfers the toner image formed on the photosensitive drum to the toner image receiver or transfers the toner image to the first surface of a transfer sheet; and a first transfer unit that transfers the toner image transferred to the toner image receiver. A second transfer means for transferring the image on the second side of the transfer sheet, an image memory for storing document information on a document table, and reading out the image memory as necessary, and the photosensitive member based on the read image information. Writing means for writing to the drum, toner image forming timing detecting means for detecting the writing timing of the toner image forming means or toner image detecting means for detecting the toner image on the photosensitive drum, and detecting the toner image on the toner image receiver Toner image receiver detecting means, document size detecting means for detecting a document size on a document table, toner image timing detecting means or toner image detecting means The information of the toner image receiving body detecting means, means for determining a toner image forming timing,
A transfer unit that feeds a transfer sheet, a drive unit that drives the photosensitive drum and the toner image receiver, and a synchronization unit that synchronizes the feed unit with the drive unit. An image forming apparatus for forming images on both sides of a transfer sheet in a single pass of the document, wherein the document is manually handled and the document size is detected to determine whether the document size is A4 or less or exceeds A4. A double-sided image forming apparatus, wherein a mode selection is made between one image formation and two image formations per rotation of a toner image receiver, and image formation is performed according to the mode selection result.

(5) Toner image forming means including a photosensitive drum, a toner image receiving member carrying a toner image formed on the photosensitive drum on its surface, and a toner image formed on the photosensitive drum Transfer means for transferring the toner image to the toner image receiver or transferring the toner image to the first surface of the transfer paper, and second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper In a double-sided image forming apparatus having a transfer unit and a fixing unit for fixing the toner images transferred to the first side and the second side, which are both sides of the transfer sheet, a double-sided image formation is performed when a jam of the transfer sheet occurs. A double-sided image forming apparatus, comprising a paper discharge tray means for discharging jams for discharging and storing transfer paper remaining in the apparatus.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1-1) A duplex image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. Embodiment 1-1 describes a double-sided image forming apparatus (printer) that forms an image by inputting external image information.
FIG. 1 is a sectional view showing the configuration of a two-sided image forming apparatus according to the present invention.
FIG. 3 is a block diagram of a main part of the double-sided image forming apparatus, and FIG. 3 is a first flowchart of the double-sided image forming apparatus. In addition,
FIG. 1 is a diagram common to the embodiment 1-1 and the embodiment 1-2, and the image reading unit is for the embodiment 1-2.

1 and 2, the toner image forming means includes a photosensitive drum 10, a scorotron charger 11, a writing unit 12, a developing unit 13, and the like. First, the photosensitive drum 10 is an image carrier, for example, a cylindrical base formed of a transparent member is provided inside, and a transparent conductive layer, a-S
A photosensitive layer such as an i-layer or an organic photosensitive layer (OPC) is formed on the outer periphery of the substrate, and is rotated in the direction of the arrow shown in the figure.

The scorotron charger 11 includes yellow (Y), magenta (M), cyan (C) and black (K).
The photosensitive drum 1 is used in the image forming process of each color of
0 in the direction orthogonal to the moving direction of the photosensitive drum 10.
It is installed facing. Further, a charging action is performed on the organic photoconductor layer of the photoconductor drum 10 by a control grid maintained at a predetermined potential and corona discharge having the same polarity as that of the toner as the discharge electrode 11a. Apply potential.

The writing section 12 writes original information in the image memory 35 onto the photosensitive drum 10.
The writing unit 12 for each color sets the exposure position on the photosensitive drum 10 between the scorotron charger 11 and the developing unit 13.
It is arranged in a state provided on the upstream side in the rotation direction of the photosensitive drum with respect to the developing sleeve 131. Further, the writing unit 12 is an exposure element 12 in which a plurality of LEDs and the like arranged in the main scanning direction in parallel with the axis of the photosensitive drum 10 are arranged in an array.
a and a Selfoc lens 12b as an equal magnification imaging element
(Product name) is attached to the holding member 20. The holding member 20 is provided with a writing unit 12, a uniform exposure unit 12c, and a simultaneous transfer exposure unit 12d for each color.
Of the substrate.

The developing unit 13 has yellow (Y) and magenta (M) developing units on the left side of the photosensitive drum 10 with respect to the rotation direction of the photosensitive drum 10, and cyan (C) and black (K). Are disposed on the right side of the photosensitive drum 10. Y and M scorotron chargers 11 are provided below the developing casing 138 of the Y and M developing units 13, and C and
C and K are located above the developing casing 138 of the K developing device 13.
Is provided. The developing units 13 for the respective colors contain one-component or two-component developers of yellow (Y), magenta (M), cyan (C) and black (K), respectively. And a developing sleeve 131 formed of an aluminum material that rotates in the same direction as the rotation direction of the photosensitive drum 10 at the developing position while maintaining a predetermined gap. Further, the developing device 13 is configured to contact the photosensitive drum 1 with an abutting roller (not shown).
When a developing action is performed by the developing unit 13 for each color, a developing bias to which a DC voltage or an AC voltage AC is further applied is applied to the developing sleeve 131, and one component contained in the developing unit is accommodated. Alternatively, jumping development using a two-component developer is performed, and a DC bias having the same polarity as that of the toner is applied to the negatively charged photosensitive drum 10 that grounds the transparent conductive layer, thereby causing the toner to adhere to the exposed portion. The developing device 13 for each of the above-mentioned colors is a non-contact state in which the electrostatic latent image on the photosensitive drum 10 formed by charging by the scorotron charger 11 and image exposure by the writing unit 12 is applied by applying a developing bias voltage. And reversal development with toner having the same polarity as the charging polarity.

The toner image receiving member 14a is an intermediate transfer member provided for temporarily transferring the toner image from the photosensitive drum 10 in the transfer area 14b. Toner image receiver 14
In a, the drive roller 14d is rotated by a motor (not shown), and the driven roller 14e is further rotated, so that the toner image receiver 14a moves in the direction of the arrow.

A transfer unit 14c, which is a first transfer unit, transfers the toner image formed on the photosensitive drum 10 to the toner image
a, or the toner image is transferred to the first side of the transfer paper P.

A transfer device 14g as a second transfer means transfers the toner image transferred to the toner image receiver 14a to the second surface of the transfer paper P.

The image memory 35 is an electronic RDH for recording document information on the document table 21. The image memory is called by a signal at a necessary timing.

Toner image detecting sensor 2 of toner image detecting means
Numeral 9 detects the toner image on the photosensitive drum 10.

The toner image formation timing detecting means detects the timing of toner image formation.

The toner image receiver detecting sensor 27 serving as a toner image receiver detector detects a toner image on the toner image receiver 14a.

The paper feeding means is fed from a paper feeding cassette 15 by a feeding roller 15a, and is conveyed to a paper feeding timing roller 15c.

The driving means drives the photosensitive drum 10 and the toner image receiving member 14a. The photoconductor drum 10 is rotated clockwise in the figure by a motor (not shown), the driving roller 14d is rotated by a motor (not shown), the driven roller 14e is further rotated by a motor (not shown), and the toner image receiving body 14a is moved by an arrow. Move in the direction of.

The synchronizing means synchronizes the paper feeding means with the driving means. The registration control unit 3 serving as a synchronization unit
In 1, the three synchronizations of the contact of the photosensitive drum 10 and the toner image receiver 14a with the photosensitive drum and the start of the transfer paper P are achieved. Further, the timing control unit 32 controls the image formation on the first surface and outputs information to the image writing control unit 40. The transfer paper feed control unit 33 controls the feed motor 15d.

The instruction means 50 is for instructing the image formation on the second surface. The control unit 30 controls execution of double-sided image formation by synchronizing the synchronizing means.

Toner image receiver cleaning device 14i
The toner remaining on the peripheral surface of the toner image receiver 14a is cleaned by a toner image receiver cleaning blade 14j that can be brought into contact with and released from the toner image receiver 14a with the support shaft 14k as a rotation fulcrum. The toner remaining on the periphery of the photosensitive drum after the transfer is subjected to static elimination by the image carrier AC static eliminator 16, and then the toner of the cleaning device 19 is scraped off by the cleaning blade 19a and collected by the screw 19b.

The fixing device 17 applies heat and pressure between the upper roller 17a and the lower roller 17b to fix the toner adhered to the first and second surfaces on the recording paper P.

In order to perform good transfer, uniform exposure is performed by a simultaneous transfer exposure device 12d using, for example, a light emitting diode.

Here, the copy operation will be described with reference to FIGS.
This will be described with reference to FIG. In addition, the code | symbol of the following parenthesis shows the code | symbol of FIG. The second side is instructed to form an image (F101), the second side image data is read out (F102), and the second side is written on the photosensitive drum by the writing unit 12 (F103). Then, an image is formed on the second surface on the photosensitive drum (F10).
4). Then, the second surface is transferred to a transfer device 14 as a first transfer unit.
c, the image is transferred to the toner image receiving body 14a (F10
5). After the transfer, the photosensitive drum 10 is stopped, the toner image receiver 14a is separated from the photosensitive drum 10, and continues to rotate (F106).

Next, an image formation instruction is given for the first side (F107).
The first-side image data is read out and standby is performed (F10
9). Then, the leading end of the image on the toner image receiver 14a is detected by the toner image receiver detection sensor 27, and a detection signal is sent to the controller 30 (F110). Here, the photosensitive drum 10,
Three synchronizations of the contact of the toner image receiver 14a with the photosensitive drum and the start of the transfer paper P are taken by the synchronization means (F111). Based on the image data in the image memory 35, the image formation of the first surface of the original on the photosensitive drum (F112) and the start of the paper feed timing roller 15c (F113) are performed. Then, the toner image on the first surface is transferred from the photosensitive drum 10 to the transfer paper P (F114), and the toner image on the second surface is transferred from the toner image receiver 14a to the transfer paper P (F11).
5) The recording paper P is synchronized with the toner image on the first surface carried on the photosensitive drum 10 and the toner image on the second surface carried on the toner image receiver 14a by driving the timing roller 15c. And is fed to the transfer area 14b.
At this time, the recording paper P is charged to the same polarity as the toner by the paper charger 14f, is attracted to the toner image receiver 14a, and is fed to the transfer area 14b. The charge is removed by an AC discharger 14h for separating the transfer paper, separated from the toner image receiving body 14a, and the transfer paper for double-sided image transfer is fixed (F1).
16) The paper is discharged by the paper discharge roller 18 (F117).

(Embodiment 1-2) A double-sided image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the above-described Embodiment 1-1, the double-sided image forming apparatus (printer) that forms an image by inputting external image information has been described. Next, a double-sided image forming apparatus (copier) having an image reading unit will be described with reference to the drawings. Will be explained. FIG. 4 is a block diagram of a main part of the double-sided image forming apparatus.
FIG. 5 is a second flowchart of the double-sided image forming apparatus. Further, description will be given with reference to FIG.
For those that do not change in function, their explanation is omitted.
In addition, members that are not changed mechanically and functionally are described with the same reference numerals. Embodiment 1-2 includes the image reading unit 22 in FIG.

In FIGS. 1 and 4, a reading section 22 is a section for reading an image on the first or second side of a document. The reading section 22 is placed on a document table 21 with a lamp 22a to illuminate the document image.
2b, lens 22c, prism 22d, and CCD2
An image is read at 2e.

Here, the copy operation will be described with reference to FIGS.
This will be described with reference to FIG. The reference numerals in parentheses below indicate the reference numerals in FIG. The original on the second side is placed on the platen 21 (F
101). Next, the second side original is read by the reading unit 22 (F102), and the second side is written on the photosensitive drum by the writing unit 12 (F103). Then, an image is formed on the second surface on the photosensitive drum (F104). Then, the second surface is transferred by the transfer unit 14c as the first transfer unit.
The image is transferred to the toner image receiver 14a (F105). After the transfer, the photosensitive drum 10 stops, and the toner image receiving body 14a
Is separated from the photosensitive drum 10 and continues to rotate (F1
06).

Next, the original on the first side is placed on the original table (F107). Next, the first-side original is read by the reading unit 22 (F108), and the first-side original is stored in the image memory 35 (F109). Then, the leading end of the image on the toner image receiver 14a is detected by the toner image receiver detection sensor 27, and a detection signal is sent to the controller 30 (F110). Thereafter, a two-sided image is formed in the same manner as in the flowchart of FIG.

(Embodiment 2) An embodiment according to claim 2 will be described with reference to the drawings. FIG. 1 is a sectional view of the configuration of the double-sided image forming apparatus, and FIG. 6 is a third flowchart of the double-sided image forming apparatus. The same members as those in FIG. 1 are denoted by the same reference numerals, and descriptions of those members that do not change mechanically or functionally are omitted.

Here, the manual copy operation will be described with reference to FIG.
This will be described with reference to FIGS. Original platen 21
(F201), and the second original is read by the reading unit 22 (F202). Further, the second surface is a photosensitive drum 1
0 is written by the writing unit 12 (F203), and the second surface is image-formed on the photosensitive drum 10 (F204). Then, the second surface is transferred to the toner image receiver 14a (F20).
5). After the transfer, the photosensitive drum 10 does not form an image but continues to rotate, and the toner image receiver 14a
And the rotation is continued (F206).

Next, the original on the first side is placed on the original platen 21 (F207), and the original on the first side is read by the reading section 22 (F208), and the first side is loaded into the image memory 35 (F2).
09). The tip of the image on the toner image receiver 14a is positioned at the toner image receiver detection center 27 which is a toner image receiver detector.
, And sends a detection signal to the control unit 30 (F210).
Three synchronizations of the contact of the photosensitive drum 10 and the toner image receiver 14a with the photosensitive drum 10 and the start of the transfer paper P are obtained by the synchronization means (F211).

Then, the first surface image is formed on the photosensitive drum 10 based on the image data in the image memory 35 (F212).
The feed timing roller 15c is started (F
213). Then, the toner image on the first surface is
0 to the transfer paper P (F214), and the toner image on the second surface is transferred from the toner image receiver 14a to the transfer paper P (F214).
215). Then, the two-sided image is fixed on the transfer paper (F21
6) and discharge the paper (F217).

In the above embodiment, a two-sided image forming apparatus (copier) having an image reading section has been described. However, a two-sided image forming apparatus (printer) for forming an image by inputting external image information is also described in the above embodiment. 1-1
The present invention can be applied in the same manner as described above.

(Embodiment 3) An embodiment according to claim 3 will be described with reference to the drawings. FIG. 7 is a fourth flowchart of the double-sided image forming apparatus. In addition, FIG.
The description will be given with reference to FIG. 4, but the description of those which do not change mechanically and functionally will be omitted, and the members which do not change mechanically and functionally will be described with the same reference numerals.

Here, the manual copy operation will be described with reference to FIG.
This will be described with reference to FIGS. First, the document on the second side is placed on the document table 21 (F301). Further, the original on the second side is read by the reading unit 22 (F302), the second side is written on the photosensitive drum 10 (F303), and the second side is image-formed on the photosensitive drum 10 (F304). And
The second surface is transferred to the toner image receiver 14a (F30
5). Further, after the transfer, the photosensitive drum 10 stops. The toner image receiver 14a is separated from the photosensitive drum 10 and stops rotating (F306). Next, the original on the first side is placed on the document table 21 (F307), the original on the first side is read (F308), and the first side is loaded into the image memory 35 (F309). The tip of the toner image on the toner image receiver 14 is detected by the toner image receiver detection sensor 27 of the toner image receiver detector and a detection signal is sent to the controller 30 (F3).
10). Then, the photosensitive drum 10, the toner image receiver 1
Three synchronizations of the contact of the photosensitive drum 4a with the photosensitive drum 4 and the start of the transfer paper P are taken by the synchronization means (F311).

The first surface image is formed on the photosensitive drum 10 based on the image data in the image memory 35 (F312), and the paper feed timing roller 15c is started (F312).
313). The first side is transferred from the photosensitive drum 10 to the transfer paper P (F314), and the second side is transferred to the toner image receiving body 1
4A to transfer paper P (F315). Then, the transfer paper P of the double-sided image is fixed (F316), and then discharged (F317).

In the above embodiment, a two-sided image forming apparatus (copier) having an image reading unit has been described. However, a two-sided image forming apparatus (printer) for forming an image by inputting external image information is also described in the above embodiment. 1-1
The present invention can be applied in the same manner as described above.

(Embodiment 4) An embodiment according to claim 4 will be described with reference to the drawings. FIG. 8 is a fifth flowchart (1) of the double-sided image forming apparatus, and FIG. 9 is a fifth flowchart (2) of the double-sided image forming apparatus. 1 and 4, the description is omitted for components that do not change mechanically and functionally, and the same reference numerals are used for members that do not change mechanically and functionally. The description will be made with reference to FIG.

The original size detecting means detects whether the original is A4 size or larger than A4 size by using the original size detection sensor 28 by using the reflected light from the original placed on the original table 21. The means for determining the toner image formation timing is based on information from a toner image timing sensor or a toner image sensor 29 as the toner image detector and a toner image receiver sensor 27 as a toner image receiver detector. , Means for setting the timing of toner image formation.

Here, the manual copy operation will be described with reference to FIG.
This will be described with reference to 4, 8, and 9. The first-side document is placed on the document table 21 (F401). Here, it is determined whether the document size detection sensor 28 is equal to or smaller than the A4 size (F4
02). First, the case of YES will be described. The two-image mode is selected (F403), and the first side is stored in the image memory 35 (F404). Then, an image is formed on the first surface of the first sheet (F405) and transferred to the toner image receiving body 14a (F4).
06). Next, an image is formed on the first side of the second sheet (F407),
Similarly, the image is transferred to the toner image receiver 14a (F408).
As a result, two identical toner images on the first surface are formed on the toner image receiver.

Next, after the transfer, the photosensitive drum 10 stops, and the toner image receiver 14a stops or continues rotating. Alternatively, the photosensitive drum 10 and the toner image receiver 14
a), the toner image receiver 14a is separated from the photosensitive drum 10 (F409). This time 2
The original on the first side is placed on the original platen 21 (F410), the second side is read (F411), and the second side is further stored in the image memory 3.
5 (F412).

Then, the leading end of the toner image on the toner image receiver 14 is detected by the toner image receiver detecting sensor 27 which is a toner image receiver detector, and a detection signal is sent to the controller 30 (F413). Here, three synchronizations of contact of the photosensitive drum 10 and the toner image receiver 14a with the photosensitive drum 10 and start of the transfer paper P are obtained (F414).

Then, a continuous second image is formed on the basis of the image data in the image memory 35 (the second image is formed on the photosensitive drum) (F415). In addition, the paper feed timing roller 15c starts two continuous sheets (F416). The second surface is transferred from the photoconductor drum 10 to the transfer paper P continuously (F417). Next, two continuous sheets are transferred from the toner image receiver 14a on the first side to the transfer paper P (F41).
8). Two continuous sheets of transfer paper P for double-sided image transfer are fixed (F419). Then, two consecutive sheets are discharged (F42).
0).

This time, the document size detection sensor 28 as document size detecting means determines whether or not the document is smaller than the A4 size (F402), and the case of NO will be described.
The one-sheet mode is selected (F421), and the first side is stored in the image memory 35 (F422). Then, an image is formed on the first side (F423), and the image is transferred to the toner image receiver 14a (F4).
24). After the transfer, the photosensitive drum is stopped and the toner image receiver is stopped, or the rotation is continued, or both the photosensitive drum and the toner image receiver 14a are continuously rotated, and the toner image receiver 14a is 10 (F425).

The original on the second side is placed on the original table 21 (F
426). Then, the second side is read by the reading unit 22 (F427), and the second side is stored in the image memory 35 (F428). Thereafter, the leading end of the image on the toner image receiver 14 is detected by the toner image receiver detection sensor 27 of the toner image receiver detector, and a detection signal is sent to the controller 30 (F42).
9). Three synchronizations of the contact of the photosensitive drum 10 and the toner image receiver 14a with the photosensitive drum 10 and the start of the transfer paper P are performed by the synchronization means (F430). One image on the second surface is formed based on the image data in the image memory 35 (image formation on the second surface of the document is performed on the photosensitive drum) (F43).
1). Further, one sheet is started by the sheet feed timing roller 15c (F432). One sheet of the second side is transferred from the photosensitive drum to the transfer paper P (F433). One sheet is transferred from the toner image receiver 14a on the first side to transfer paper (F434).
Then, one sheet of transfer paper P for double-sided image transfer is fixed (F43).
5). Then, one sheet is discharged (F436). Thus, a double-sided image is obtained.

(Embodiment 5) An embodiment according to claims 5 and 6 will be described with reference to the drawings. FIG. 10 is a sectional view of the configuration of the double-sided image forming apparatus, and FIG. The same members as those in FIG. 1 are denoted by the same reference numerals, and descriptions of those members that do not change mechanically or functionally are omitted.

In FIG. 10, the sorting guide 25 is rotated by a driving mechanism (not shown).
Are divided into two. When a jam of the transfer paper occurs during copying, the jam is detected by a jam detection sensor (not shown), and the driving mechanism is operated. Further, the distribution guide 25 guides the transfer paper P conveyed by the toner image receiver 14a in the direction of the fixing device 17 in the solid line state of FIG.
Further, the transfer paper P conveyed by the toner image receiving body 14a in the dotted line state in FIG. 10 is guided in the direction of the paper discharge tray 24 for jam clearance. In addition, 26 is the transfer paper P
Is a belt unit that conveys the image. Paper output tray 2 for jam clearance
Reference numeral 4 denotes a tray for discharging the transfer sheet P during image formation remaining in the apparatus when the transfer sheet P is jammed in the apparatus. In the embodiment, since the sorting guide 25 is provided on the side of the fixing device 17 of the toner image receiving member 14a, for example, when the transfer sheet P is jammed in the fixing device 17 during the continuous copy mode, the paper feeding is performed. The transfer paper P remaining on the feed roller 15b, the feed timing roller 10c, and the like, and the transfer paper P remaining on the toner image receiver 14a from the cassette 15 are sorted by the sorting guide 25, and the jam-ejecting discharge tray is used. 24. Further, for example, when a paper jam occurs during paper supply from the paper supply cassette 15 in the continuous copy mode, the transfer paper P remaining on the toner image receiver 14a is discharged to the paper discharge tray 24 for paper jam processing. In addition, the feeding roller 15
(b) If the transfer sheet P is jammed by the feed timing roller 10c or the like, the fixing is completed if there is transfer sheet in the fixing device 17.

Here, a case where the transfer paper jams due to separation of the paper feed cassette 15 during the operation in the continuous copy mode will be described with reference to FIGS. If the transfer paper jams due to separation of the paper feed cassette 15 during operation in the continuous copy mode (F501), the paper feed cassette 1
A jam detection sensor (not shown) provided at the separation portion of No. 5 detects occurrence of a jam (F502). Here, the jam tray controller operates (F503), and the distribution guide 25 rotates counterclockwise (F505). Toner image receiver 14
The transfer paper P remaining in a is continuously transported (F50).
6), the transfer paper is discharged to the paper discharge tray 24 for jam clearance (F507). On the other hand, even if transfer paper jam occurs,
The operation of the remaining process is continued (F504). For example, when there is a transfer sheet in the fixing device 17, the fixing is terminated and the operation is stopped (F508). Thereafter, the transfer sheet on which the paper jam has occurred due to the separation of the sheet feeding cassette 15 is taken out (F509).

As described above, when a jam of the transfer paper P occurs, the transfer paper P, for example, on the toner image receiver 14a is stored in the paper discharge tray 24 for jam processing as it is.
The operation of removing the transfer paper P remaining in the apparatus is omitted. Also, forgetting to remove the remaining transfer paper can be prevented. In particular, the difficulty of removing the transfer paper electrostatically attracted to the toner image receiver 14a when jamming occurs is eliminated. Further, the transfer paper P being conveyed from the paper supply cassette 15 to the toner image receiver 14a is also stored in the paper discharge tray for jam clearance.

In the above embodiment, the double-sided image forming apparatus (printer) for forming an image by inputting external image information has been described. However, the present invention is similarly applicable to a double-sided image forming apparatus (copier) having an image reading unit. Can be applied. Further, the paper discharge tray 2 for jam clearance according to the embodiment
Although the sorting guide 25 is provided between the toner image receiving body 14a and the fixing device 17, the present invention is not limited to this, and may be between the fixing device 17 and an external discharge tray.

Although the above embodiments have been described with respect to a double-sided image forming apparatus for forming a color image, the present invention is similarly applied to a double-sided image forming apparatus for forming a monochrome image.

[0060]

According to the structure described above, the following effects can be obtained.

According to the first aspect of the present invention, double-sided image formation can be performed by manually reversing the original, and the memory capacity can be reduced as compared with the case where the ADF is used. Further, since the rotation of the toner image receiver is continued after the transfer to the toner image receiver, it is not necessary to restart the toner image receiver. This eliminates the need for a device or control for stopping and restarting the toner image receiver. In addition, it is possible to prevent the speed unevenness immediately after the start, which tends to occur at the time of the restart.

According to the second aspect of the present invention, double-sided image formation can be performed by manually reversing the original, and the memory capacity can be reduced as compared with the case where the ADF is used. Further, since the rotation of the toner image receiver is continued after the transfer to the toner image receiver, it is not necessary to restart the toner image receiver. This eliminates the need for a device or control for stopping and restarting the toner image receiver. In addition, it is possible to prevent speed unevenness immediately after the start, which is likely to occur at the time of restart, and because the photosensitive drum continues to rotate, it is possible to prevent speed unevenness at the time of starting the photosensitive drum rotation, so that the writing timing can be shortened accordingly. it can.

According to the third aspect of the invention, double-sided image formation can be performed by manually reversing the original, and the memory capacity can be reduced as compared with the case where the ADF is used. In addition, since the toner image receiver is stopped, the durability of the belt of the toner image receiver and the driving rotation unit of the toner image receiver increases.

According to the fourth aspect of the invention, in the case of A4 size (small size) copying, copying can be performed in units of two sheets, and the copying work can be shortened.

According to the fifth aspect of the present invention, the operation of removing the transfer paper remaining in the apparatus can be omitted, and the forgetting to remove the remaining transfer paper can be prevented. In particular, the difficulty of removing the transfer sheet electrostatically attracted to the toner image receiving member during jamming is eliminated.

According to the present invention, when a paper jam occurs, the transfer paper remaining in the transfer paper transport path from the paper supply cassette to the top of the toner image receiver is discharged to a paper discharge tray for jam processing. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a two-sided image forming apparatus.

FIG. 2 is a block diagram of a main part configuration of the double-sided image forming apparatus.

FIG. 3 is a first flowchart of the double-sided image forming apparatus.

FIG. 4 is a main block diagram of the double-sided image forming apparatus.

FIG. 5 is a second flowchart of the double-sided image forming apparatus.

FIG. 6 is a third flowchart of the duplex image forming apparatus.

FIG. 7 is a fourth flowchart of the double-sided image forming apparatus.

FIG. 8 is a fifth flowchart (1) of the double-sided image forming apparatus.
FIG.

FIG. 9 is a fifth flowchart (2) of the double-sided image forming apparatus.
FIG.

FIG. 10 is a cross-sectional view illustrating a configuration of a double-sided image forming apparatus.

FIG. 11 is a flowchart of a transfer sheet jam process.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum 12 writing unit 13 developing device 14a toner image receiver 14b transfer area 14c transfer device 14g transfer device 15 paper feed cassette 15a feed roller 15b feed roller 15c feed timing roller 15d feed motor 18 discharge roller 21 original Table 22 Image reading unit 24 Paper discharge tray for jam processing 25 Sorting guide 27 Toner image receiver detection sensor 28 Document size detection sensor 29 Toner image detection sensor 30 Control unit 35 Image memory 50 Instruction means P Transfer paper

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsu Haneda Konica Corporation, 2970 Ishikawa-cho, Hachioji-shi, Tokyo (72) Inventor Kunio Shigeta Konica Corporation, 2970 Ishikawa-cho, Hachioji-shi, Tokyo (72) Inventor Yotaro Sato 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation

Claims (6)

[Claims] A toner image forming means including a photosensitive drum, a toner image receiving member which is an intermediate transfer member of the toner image, and a toner image formed on the photosensitive drum is transferred to the toner image receiving member. First transfer means for transferring the toner image to the first surface of the transfer paper, second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper, and recording image information Image memory, writing means for writing to the photosensitive drum based on image information in the image memory, and toner image forming timing detecting means for detecting the formation timing of the toner image or toner image detecting means for detecting the toner image on the photosensitive drum And a toner image receiver detecting means for detecting a toner image on the toner image receiver,
The toner image forming timing detecting means or the toner image detecting means, a paper feeding means for feeding a transfer sheet based on the information of the toner image receiving body detecting means, and a drive for driving the photosensitive drum and the toner image receiving body Means, synchronization means for synchronizing the paper feeding means and the driving means, instruction means for instructing image formation on the second side, and a control unit for controlling execution of double-sided image formation. After forming an image on the photoconductor drum, after transferring the toner image from the photoconductor drum to the toner image receiver, the photoconductor drum stops rotating,
The toner image receiver is separated from the photoconductor drum, continues to rotate, and, in response to an instruction signal from the instruction unit, the photoconductor drum for forming an image on the second surface by the synchronization unit, and the toner. A two-sided image forming apparatus, wherein a two-sided image is formed by the control unit by synchronizing an image receiving body and the sheet feeding unit. 2. A toner image forming means including a photosensitive drum, a toner image receiving member as an intermediate transfer member of the toner image, and a toner image formed on the photosensitive drum is transferred to the toner image receiving member. First transfer means for transferring the toner image to the first surface of the transfer paper, second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper, and storing image information An image memory, writing means for writing to the photosensitive drum based on image information of the image memory, and toner image forming timing detecting means for detecting a toner image forming timing or a toner image for detecting a toner image on the photosensitive drum Detecting means, toner image receiver detecting means for detecting a toner image on the toner image receiver, toner image forming timing detecting means or toner image detecting means, According to the information of the toner image receiver detecting means, the paper feeding means for transferring the transfer paper, the driving means for driving the photosensitive drum and the toner image receiving body, and the synchronizing of the paper feeding means and the driving means A synchronizing unit, an instructing unit that instructs image formation on the second side, and a control unit that controls execution of double-sided image formation. After forming the first side of the document on the photosensitive drum, After transferring the toner image to the toner image receiver, the photoconductor drum continues to rotate, the toner image receiver separates from the photoconductor drum, continues to rotate, and responds to an instruction signal from the instruction unit. Wherein the synchronizing means synchronizes the photosensitive drum, the toner image receiver, and the paper feeding means for forming an image on the second side, and forms a double-sided image by the control unit. Forming equipment. 3. A toner image forming means including a photosensitive drum, a toner image receiving member as an intermediate transfer member of the toner image, and a toner image formed on the photosensitive drum is transferred to the toner image receiving member. First transfer means for transferring the toner image to the first surface of the transfer paper, second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper, and storing image information An image memory, writing means for writing to the photosensitive drum based on document information in the image memory, and toner image forming timing detecting means for detecting a toner image forming timing or a toner image for detecting a toner image on the photosensitive drum Detecting means, toner image receiver detecting means for detecting a toner image on the toner image receiver, toner image forming timing detecting means or toner image detecting means, Paper feeder for feeding the transfer paper, drive for driving the photosensitive drum and the toner image receiver, and synchronization for synchronizing the paper feeder with the drive based on the information of the toner image receiver. Means for instructing image formation on the second side, and a control unit for controlling execution of double-sided image formation. After forming the first side of the document on the photosensitive drum, the toner is transferred from the photosensitive drum to the toner. After transferring the toner image to the image receiving member, the photosensitive drum stops rotating, the toner image receiving member separates from the photosensitive drum, stops rotating, and responds to an instruction signal from the instruction means. Wherein the synchronizing means synchronizes the photosensitive drum, the toner image receiver, and the paper feeding means for forming an image on the second side, and forms a double-sided image by the control unit. apparatus. 4. A toner image forming means including a photosensitive drum, a toner image receiving member which is an intermediate transfer member of the toner image, and a toner image formed on the photosensitive drum is transferred to the toner image receiving member. First transfer means for transferring the toner image to the first surface of the transfer paper, second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper, and a document on a platen An image memory for storing information;
A writing unit that reads the image memory as needed and writes the photosensitive drum based on the read image information; and a toner image forming timing detecting unit that detects a writing timing of the toner image forming unit or a photosensitive drum. Toner image detection means for detecting a toner image, toner image receiver detection means for detecting a toner image on a toner image receiver, document size detection means for detecting a document size on a platen, and toner image timing detection Means for determining the timing of forming a toner image based on information from the means or the toner image detecting means and the toner image receiving body detecting means, a paper feeding means for feeding a transfer sheet, the photosensitive drum and the toner image receiving body. A driving unit for driving, and a synchronizing unit for synchronizing the paper feeding unit and the driving unit, wherein the transfer is performed by one pass of the transfer paper. An apparatus for forming an image on both sides of the toner image receiving device, wherein the manual operation of the original is performed manually, and the original size is detected to determine whether the original size is smaller than A4 or larger than A4. A double-sided image forming apparatus, wherein a mode selection is performed to form two or two images, and an image is formed according to the mode selection result. 5. A toner image forming means including a photosensitive drum, a toner image receiving member carrying a toner image formed on the photosensitive drum on a surface, and a toner image formed on the photosensitive drum. First transfer means for transferring the toner image to the image receiving member or transferring the toner image to the first surface of the transfer paper; and second transfer means for transferring the toner image transferred to the toner image receiver to the second surface of the transfer paper. A fixing unit for fixing the toner images transferred on the first and second sides of the transfer sheet,
A two-sided image forming apparatus, comprising a paper discharge tray unit for jam processing for discharging and storing the transfer paper remaining in the two-sided image forming apparatus when the transfer paper is jammed. 6. The paper discharge tray for jam processing branches to the paper discharge tray for paper jam between transfer paths of transfer paper from the toner image receiver to the fixing means. A double-sided image forming apparatus according to claim 5.