JPH07160126A - Synthetic transfer device - Google Patents

Abstract

PURPOSE:To provide a device capable of unnecessitating a transfer voltage, or a current output at high level as a conventional one, and also, capable of suppressing the occurrence of ozone than heretofore. CONSTITUTION:The device is provided with a layering information instruction switch 24 for instructing that two original images are composited on one sheet of paper 106, a transfer drum 107 for holding the paper 106 and rotated adjacently to a photoreceptor drum 101 in synchronism with the rotation of the photoreceptor drum 101, a transfer electrode 13 on which a voltage, or a current is impressed at a prescribed timing in order to transfer the original image formed on the photoreceptor drum 101 to the paper 106 placed on the surface of the transfer drum 107 in accordance with the rotation of the transfer drum 107, and the device is also provided with a control substrate 21 for controlling so that the voltage, or the current may not be impressed on the transfer electrode 13 in a substantial transfer area for the remaining original image other than the original image which is on the way of transferring to the paper 106 at the time of successively transferring two original images to the paper 106, in the case the instruction is given by the synthetic information instruction switch 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite transfer device for an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus, for example, a full color image forming a visible image of color by sequentially transferring a maximum of four color toner images formed on a photoconductor using a transfer drum onto a copy sheet. In a copying machine, a transfer electrode for electrostatically transferring a toner image on a photoconductor onto a copy sheet by using corona discharge is provided inside a transfer drum so as to be close to the photoconductor. The configuration and operation of an example of such a full-color copying machine will be described with reference to FIG.

That is, in FIG. 1, the photosensitive drum 1
The surface of 01 is uniformly charged by the charging electrode 102 (charging step).

A light image of a document (not shown) placed on the document table 103 is decomposed by a color separation filter (not shown), and a specific light image decomposed through a predetermined color separation filter (blue filter) is formed. The photoreceptor drum 101 is exposed to light to form an electrostatic latent image of a specific color (yellow as a complementary color to the blue filter) (color separation exposure step).

For example, for a yellow electrostatic latent image,
A developing unit 104 having four color (yellow, magenta, cyan, and black) developing units movably arranged near the photoconductor drum 101 moves, and yellow toner having a charge opposite in polarity to the latent image is moved. The yellow toner developing device 104a in which is stored is set at a predetermined position of the photosensitive drum 101, and a toner image is developed using yellow toner (developing step).

On the other hand, the paper 106 supplied from the copy paper cartridge 105 is rotatably arranged in the full-color copying machine 100 at a substantially central portion thereof so as to be close to the photosensitive drum 102. Is held in place. Inside the transfer drum 107, a transfer electrode 108 for electrostatically transferring the toner image onto the paper 106 by using corona discharge is provided.

The transfer drum 107 rotates in synchronism with the photosensitive drum 101 while holding the paper 106, and has a predetermined high voltage (V _k ; k = 1-4 integer) of about 5 kV.
k indicates the k-th transfer step), but the polarity of the toner is changed by corona discharge from the back side of the transfer electrode 108 applied to the paper 106 for a certain time (T) according to the paper size. The opposite charge is given. As a result, the toner is attracted to the front side of the sheet by the electrostatic force, and the toner image on the photosensitive drum 101 is transferred onto the sheet 106 (transfer step).

Further, residual toner and the like remaining on the surface of the photosensitive drum 101 are removed and cleaned (cleaning step).

Each of the above steps is performed for four cycles until four color toner images are sequentially transferred onto the same paper 106 and transfer of all colors is completed. In this case, in order to maintain the transfer efficiency, the transfer voltage V _k (k = 1 to
4) must be increased. Transfer drum 107
If the material is PVdF (polyvinylidene fluoride),
Especially, the necessity increases. That is, V ₁ <V ₂ <V ₃ <
It becomes V ₄ .

After that, the four color toner images are transferred, and the paper 106 separated from the transfer drum 107 is fixed to the fixing device 1.
The toner is conveyed to 09, heated, mixed with toner and fixed (fixing step), and color transfer is completed.

Next, by using the above-mentioned full-color copying machine, a plurality of original images, for example, as shown in FIG.
When the color original images of different types (see FIG. 6A) are composite-transferred in color on the same surface of one sheet (see FIG. 6B) (hereinafter, this composite transfer is referred to as “2 in 1 color transfer”). ), The operation will be described mainly with reference to FIG.

The operator turns on a composite transfer instruction switch (not shown), instructs the size (A4 size) of the paper 106 by means of a paper size selection switch (not shown), and further specifies the reduction ratio (71%) of the original. Then, Fig. 6
The document 1 (A4 size) shown in FIG.
Then, the copy start switch (not shown) is turned on. Here, the predetermined position means that the transfer position of the original document 1 after composition is relative to the selected paper size.
It is a position considered so as to be closer to the front end portion 106a of the paper than the center.

The transfer voltage V applied to the transfer electrode 108 when the transfer drum 107 makes four revolutions for sequentially transferring the color toner images of four colors for the above-mentioned reason.
_{k, n} (where k is an integer of 1 to 4 and n is an integer of n ≧ 1. Here, k represents the k-th transfer step as described above, and n represents the n-th original image. Is shown)
Is n = 1 because the original image is the first, and V _1,1 <
_V2,1 < _V3,1 < _V4,1 .

When the color transfer of the first original 1 is completed,
When the second original 2 is placed at a predetermined position on the original placing table 103 and the copy start switch is turned on, the transfer drum 107 holding the same paper 106 is moved to the same position as that of the first original 1. Rotate.

For the second original 2 (A4 size) as well, in order to maintain the transfer efficiency similarly to the original 1, it is necessary to apply a voltage higher than the transfer voltage for the original 1.

That is, V _4,1 <V _{k, 2} (k = 1 to 4), and as shown in FIG. 7, in order to perform "2 in 1 color transfer", the transfer voltage is at least 8
Voltage levels in stages are required, and V _1,1 <V _{2, 1} <V _{3, 1} <
It is necessary to satisfy the relationship of V ₄ , ₁ <V _{1, 2} <V _{2, 2} <V _{3, 2} <V ₄ , ₂ . It should be noted that the transfer voltage V _{k, n} is irrespective of the substantial transfer area of the original image on the paper 106.
6 area (that is, the leading edge portion 106a of the sheet excluding the sheet holding portion on the transfer drum 107 shown in FIG. 6B).
To the rear end portion 106b of the sheet). Therefore, the transfer voltage application time (ON
T as time) is determined by the selected paper size information, the predetermined rotation speed of the transfer drum 107, and the like.

As described above, "2 in 1 color transfer" as shown in FIG. 6B is performed.

[0018]

However, in such a structure, in order to maintain the transfer efficiency, the transfer voltage V _{k, n} (where k = 1 to 4 is an integer; n ≧ 1 is an integer) at each transfer step. ) Needs to be increased, for example, “2 in
When performing "one color transfer", the transfer voltage V _{k, n} requires at least eight voltage levels, and V _1,1
<V _{2, 1} <V _{3, 1} <V _{4, 1} <V _{1, 2} <V _{2, 2} <V _{3, 2} <V _{4, 2}
It was necessary to satisfy the relationship. Therefore, it is necessary to output a transfer voltage or current at a higher level in a wide range, and it is necessary to provide an expensive high-voltage generator, which leads to an increase in the cost of the entire copying machine.

Further _, by increasing the transfer voltage V _{k, n,} etc. at each transfer step, the higher the voltage level, the more ozone is generated.

The present invention, in consideration of such a problem of the composite transfer device in the conventional image forming apparatus, does not require the transfer voltage or current output at a high level as in the prior art, and the generation of ozone can be suppressed by the conventional method. It is an object of the present invention to provide a synthetic transfer device that can be suppressed compared to the above.

[0021]

According to the present invention of claim 1, there is provided a combination instruction means for instructing to combine a plurality of original images on one copy sheet, a copy sheet held, and a photosensitive member. A transfer drum that rotates in close proximity to the photoconductor in synchronism with rotation, and the original image formed on the photoconductor is transferred onto the copy paper held on the surface of the transfer drum as the transfer drum rotates. When a transfer electrode to which a voltage or a current is applied at a predetermined timing and an instruction from the combining instruction unit are received, when a plurality of original images are sequentially transferred to one copy sheet, A composite including a transfer electrode control unit for controlling so that no voltage is applied to the transfer electrode in the substantial transfer area of the whole or a part of the original image with respect to the original image being transferred to the copy sheet. It is a transfer device.

According to a second aspect of the present invention, the transfer electrode control means prevents the transfer electrode from being applied to the original image being transferred in a substantial transfer area of the already transferred original image. , A synthetic transfer device for controlling.

[0023]

In the present invention, the combining instruction means gives an instruction to combine a plurality of original images on one copy sheet. The transfer drum holds the copy sheet and rotates in proximity to the photoconductor in synchronization with the rotation of the photoconductor, and the transfer electrode is formed on the photoconductor as the transfer drum rotates. A voltage or current is applied at a predetermined timing to transfer the original image onto the copy sheet held on the surface of the transfer drum. When an instruction to combine a plurality of original images on one copy sheet is received from the combining instruction means, the transfer electrode control means, when sequentially transferring the plurality of original images to one copy sheet, the transfer electrode control means The control is performed so that no voltage is applied to the transfer electrode in the substantial transfer area of the whole or a part of the original image with respect to the original image being transferred onto one copy sheet.

[0024]

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

FIG. 1 is a schematic side view for explaining a partial structure of a full-color copying machine including a synthetic transfer device according to an embodiment of the present invention and a block diagram for explaining a control operation of a transfer electrode. The configuration of this embodiment will be described with reference to FIG. The components having basically the same functions as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

The transfer drum 107 has a paper clip 11 for holding the front end of the paper 106 in order to hold the paper 106 on its surface. The sheet position detection sensor 12 is composed of a photocoupler light emitting portion 12a fixed at a predetermined place inside the main body of the full-color copying machine 10 and a photocoupler light receiving portion 12b on the side of the transfer drum 107 at a predetermined position opposite thereto. ing. Here, the predetermined position means the paper 1
This is the position where the optical path of the paper position detection sensor 12 is blocked when 06 is correctly held and starts rotating together with the transfer drum 107.

On the other hand, the control board 21 as the transfer electrode control means of the present invention is provided at a predetermined position inside the main body of the full-color copying machine 10 and has a timer function or the like to control the operation of each part. The transfer high-voltage unit 22 is a means provided at a predetermined position inside the main body of the full-color copying machine 10. The transfer high-voltage unit 22 includes a voltage level of the transfer voltage applied to the transfer electrode 13 and timing signals for starting and releasing the application. A high-voltage transfer voltage is generated based on the instruction information from the control board 21, and is output to the transfer electrode 13.

The paper size selection switch 23 is a switch for the operator to select a desired copy paper size, and the composite information instruction switch 24 is a "number information" of the composite image of the original image to be transferred by the operator. “Position information” of each document image after the composite transfer for determining to which position on the sheet of paper 106 the composite transfer is performed, and “copy magnification information” at the time of the composite transfer of each document image A black / white / color selection switch 25 is a switch for selecting in advance, a switch for selecting a color tone of a document image after copying, and a copy start switch 26 is an operation switch for instructing the start of a copying operation. Is. All of these switches are arranged on the operation panel (not shown) of the full-color copying machine 10, and the control board 2 is an electric circuit.
Connected to 1.

With the above-described structure, the operator can use, as shown in FIGS.
Two types of color document images of A4 size document 1 and document 2 (see FIG. 3A) as shown in FIG. 3 are composite-transferred to a uniform area in color on the same surface of one A4 size sheet. (See FIG. 3B) The operation of the present embodiment will be described with a focus on the case. Here, FIG. 3A is an explanatory diagram showing two types of color original images of an A4 size original 1 and an original 2, and FIG. 3B shows the same surface of one A4 size sheet. FIG. 9 is an explanatory diagram showing a result of composite transfer to a color uniform area. However, the relative dimensional relationship in the drawing of each sheet in FIG. 3 does not necessarily match the relative dimensional relationship as the original sheet size (for example, the above A4 size).

That is, as shown in FIG. 1, the operator first selects the size "A4" from the paper size selection switch 23.

Next, "2" is input as the "information of the number of original images" to be combined by the combination information instruction switch 24 (if not combining, "1" is input), and after each combination transfer. As the “transfer position information” of the document image, the A1 size document 1 (see FIG. 3A) is fed to the front end portion 106 of the paper 106.
The "front half area" of the entire sheet based on a (Fig. 3
(See (b)), and the document 2 (see FIG. 3 (a)) is transferred to the “rear half region” (see FIG. 3 (b)) of the entire sheet with reference to the leading edge 106a of the sheet 106. Enter. Further, from the composite information instruction switch 24, as the "copy magnification information", it is inputted that each original image is reduced to "71%".

Further, "color" is selected from the monochrome / color selection switch 25, the original 1 and the original 2 shown in FIG. 3A are placed on the automatic original feeder (not shown), and the copy start switch 26 is turned on. Turn on.

The control operation of the transfer high-voltage unit 22 by the control board 21 and the like will be mainly described below mainly with reference to the flowcharts shown in FIGS. 1 and 4. Here, FIG. 4 is a flowchart for mainly explaining the control operation of the transfer high-voltage unit 22 in this embodiment.

Upon receipt of the above information and the like, the control board 21 automatically supplies the original 1 to the original placing table 103 from the automatic original feeder, and transfers the A4 size paper 106 to the transfer drum 10.
7, the copying operation is started for each unit (step 11).

Paper 106 supplied to transfer drum 107
Is a toner image formed on the photoconductor drum 101 by sandwiching the front end portion 106a of the paper clip 11 (yellow toner is used in the first transfer).
In synchronism with the above, rotation is started in the direction of arrow A (see FIG. 1) while being wound around the surface of the transfer drum 107. The paper leading end portion 106a shuts off the optical path of the paper position detection sensor 12 with the start of rotation, and the photocoupler light receiving portion 12b turns off.
Change from N state to OFF state. The OFF state of the photocoupler light receiving unit 12b is continued until the paper 106 has completed passing through the predetermined location of the sensor, is released again after the completion of passing, and is turned on again. This ON /
The change in the OFF state is used as information that will be described later, such as determining the timing of applying the transfer voltage and counting the number of times of transfer.

As described above, when the paper 106 changes from the ON state to the OFF state of the photocoupler light receiving portion 12b, the state change information is transmitted to the control board 21 and the timing signal is turned ON, until then. The timer A (not shown) in the control board 21, which was in the standby state, starts time counting (step 12).

In step 13, it is determined that the mode is the composite transfer mode based on "2" of "original image number information" already input from the composite information instruction switch 24, and the process proceeds to step 14. However, if the operator has instructed to perform normal color transfer without performing the composite transfer (enter "1" if the composite transfer is not performed), the process proceeds from step 13 to step 20. In step 16, the transfer operation is repeated four times (or once in the case of black and white) basically by the same method as the conventional method, and the transfer operation is finished (step 22).

The control board 21 is based on the information on the number of times the same original image is transferred by the paper position detection sensor 12 and the "color" selection information by the monochrome / color selection switch 25.
Is a composite document with two original images currently being transferred.
Determine whether it is the first original or the second original (step 1
4). Here, the first sheet is determined and the process proceeds to step 15.

On the other hand, before proceeding to step 15, the control board 2
1 is based on information such that the first original, that is, the original 1 is reduced to 71% and is transferred to the “front half area” of the entire A4 size paper with the leading edge 106a of the paper 106 as a reference. And decide the next.

That is, the ON time of the transfer output of the transfer high-voltage unit 22 (that is, the transfer voltage application time) T
₂ indicates that the "front half area" of the paper 106 is above the transfer electrode 13 from the timing when the timer A in the control board 21 which started the time counting at the above timing and the paper leading edge 106a thereafter passes the transfer electrode 13. It is determined by the control board 21 as a scheduled time for counting the timing until the end of passage. As a result, the transfer voltage application start timing (t _{on, 1} ) and the application release timing (t _{on, 1} )
_{off, 1} ) are also decided.

Further, information on the number of times of transfer of the same original image by the paper position detection sensor 12 (1 in the case of color in this embodiment).
The output voltage of the transfer high-voltage unit 22 (that is, the transfer voltage) V _k (k is an integer of 1 to 4) is determined based on (4 times), which is once for black and white.

In step 15, the transfer electrode 13 operates based on the transfer voltage V _k of the transfer high voltage unit 22 thus _obtained and the control information such as the application time T ₂ .

As described with reference to FIG. 7, it is necessary to increase the voltage level of the transfer voltage V _k in each of the first to fourth color transfer processes. Here, FIG. 2 shows the transfer voltage V _k , the application time T _2, etc. of the composite color transfer in this embodiment in comparison with the case of the prior art (shown in FIG. 7). From the figure, for example, the transfer voltage V ₁ in the _first transfer step of the original 1 is the same as the conventional V _1,1 and V ₁ = V _1,1 , but the application time T ₂ is Since control is performed so that only the entire "first half area" (see FIG. 3B) is applied, T ₂ = T / 2 in half the time of the conventional case.
Becomes

In this way, the first transfer process of the original 1 is completed, and the process proceeds to step 16 to determine whether the transfer process has been completed four times in the case of color (one in the case of black and white). To do.

Here, in the case of color, which may be the place where the first transfer process is completed, the process immediately returns to the step immediately before step 12, and the above-mentioned steps (steps 12 to 12).
Repeat step 16) three more times. When the four-color full-color composite transfer of the original 1 is completed, the process proceeds from step 16 to step 21 to determine whether or not there is an untransferred original,
As a result, since the transfer process of the original 2 still remains, the process returns to the step immediately before step 12, and the next original 2 is placed on the original table 10.
Wait until it is set to 3. When the original 2 is automatically supplied to the original placing table 103 from the automatic original feeder,
Go to step 12, step 1 in the judgment of step 14
Proceed to 7.

In step 17, the "front half area" (see FIG. 3B) of the entire sheet on which the document 1 is transferred is excluded,
The waiting time is set in order to control the application of the transfer electrode 13 only to the remaining "rear half region".

In other words, this waiting time is controlled by the control board 21.
After timer A inside starts counting time,
The control board 21 determines the time until the “first half area” of 06 has finished passing over the transfer electrode 13 (in the case of the original 1, this waiting time is set by the timer A in the control board 21. After starting counting, the leading edge of the paper 10
6a is the time until it passes through the transfer electrode 13 and is always constant regardless of the paper size and the like).

As a result, the transfer voltage application start timing (t _{on, 2} ) and the application release timing (t _{off, 2} ) are also determined.

The elapse of the waiting time is judged (step 1
8) The process proceeds to step 19, and the transfer voltage V _k of the transfer high-voltage unit 22 thus _obtained and the application time T
₂ (in the case of the present embodiment, the transfer areas of the original 1 and the original 2 are the same for the front half and the rear half of the paper 106, so the application time is the same), and the transfer electrode 13 operates based on control information such as (See FIG. 2).

Thereafter, step 16 is passed four times in the same manner as described above, and step 21 is followed by step 22 to complete the synthetic transfer operation.

As described above, it is necessary to increase the voltage level of the transfer voltage V _k for every four transfer steps of color transfer, as described with reference to FIG.
Here, the most important points that are basically different from the conventional ones are as follows.

That is, when the original 1 is transferred, the paper 1
The application timing of the transfer voltage is controlled so that the application area of the transfer voltage on 06 does not reach the area of the original 2 after the composite transfer, and the application area of the transfer voltage does not become the entire area of the paper 106 as in the conventional case. That is the point.

As a result, as shown in FIG. 2, when the original 2 is composite-transferred, V _{4, 1} (original 1 4
Transfer voltage in the second transfer process) <V _{k, 2} (k of original 2)
The relationship of the transfer voltage; k = 1 to an integer of 4) in the transfer step of the second time becomes unnecessary, and therefore, eight voltage levels are required,
And V _1,1 <V _{2, 1} <V _{3, 1} <V _{4, 1} <V _{1, 2} <V _{2, 2} <V
It is not necessary to satisfy the relationship of _{3, 2} <V ₄ , ₂ .

Therefore, the level of the transfer voltage V _{k for} the original 2 is the same as that for the original 1, and the upper limit of the level of the transfer voltage is V ₄ = V _4,1. As 22, it is possible to use the same one as a full-color copying machine which does not have a conventional synthetic transfer device.

Further, the amount of ozone generated can be suppressed to the same level as that of a full-color copying machine having no conventional synthetic transfer device.

Further, when the original 2 is transferred, the paper 106
In the above description, the transfer voltage is not applied to the transfer area of the document 1 that has already been transferred,
No adverse effects such as reverse transfer occur.

In the above embodiment, the case where the number of original images to be combined is two has been described, but the number of original images to be combined is not limited to this.

Further, in the above embodiment, two original images are converted into one.
The case has been described in which the leading edge of a sheet of paper is used as a reference for allocating to a balanced region such as the first half and the second half, but the invention is not limited to this. Of course, it is not necessary to be assigned.

In the above embodiment, the transfer areas of the two original images are not overlapped by the transfer voltage application areas, but the present invention is not limited to this. When there are a plurality of original images to be transferred, it is a matter of course that the transfer area of the already transferred original image may entirely or partially overlap the transfer voltage application area of the remaining original images.

In the above embodiment, the transfer positions of the two original images are set in the order in which the original images are transferred.
Although the case where the transfer position is sequentially determined from the leading end portion of the sheet has been described, the present invention is not limited to this. For example, assuming that the original 1 is transferred first and the original 2 is transferred last, the respective transfer positions on the sheet are In the case where 2 is the front end side of the paper and the original 1 is at the rear end side of the paper, the relationship between the transfer order of the original images and the transfer position of the original images on the paper is not important.

The present invention can be applied not only to the copying machine but also to other image forming apparatuses such as printers and facsimiles.

Further, the present invention may be realized by hardware using each component, or not limited to this, and may be realized by software.

[0063]

As is apparent from the above description,
The present invention according to claim 1 has an advantage that a high level transfer voltage or current output as in the prior art is not required and the generation of ozone can be suppressed as compared with the prior art.

In addition to the above effects, the present invention according to claim 2 has an advantage that adverse effects such as reverse transfer do not occur.

[Brief description of drawings]

FIG. 1 is a schematic side view for explaining a partial structure of a full-color copying machine including a synthetic transfer device according to an embodiment of the present invention and a block diagram for explaining a control operation of a transfer electrode.

FIG. 2 is a transfer voltage V for composite color transfer in the embodiment.
_k , application time T ₂ etc. in the case of the conventional technique (shown in FIG. 7)
Explanatory diagram for explaining in comparison with

FIG. 3A is an explanatory view showing two types of color original images of an A4 size original 1 and an original 2; FIG. 3B is a composite transfer in a color uniform area on the same surface of one A4 size sheet. Explanatory diagram showing the results

FIG. 4 is a flowchart for mainly explaining a control operation of the transfer high-voltage unit in the embodiment.

FIG. 5 is a block diagram of a conventional full-color copying machine.

FIG. 6A is an explanatory view showing two types of color original images of an A4 size original 1 and an original 2; FIG. 6B is a composite transfer to a color uniform area on the same surface of one A4 size sheet. Explanatory diagram showing the results

FIG. 7 is an explanatory view showing the level of a transfer voltage at the time of synthetic transfer of a conventional full-color copying machine.

[Explanation of symbols]

 10 Full Color Copier 11 Paper Clip 12 Paper Position Detection Sensor 12a Photocoupler Light Emitting Section 12b Photocoupler Light Receiving Section 13 Transfer Electrode 21 Control Board (Transfer Electrode Controlling Means) 22 Transfer High Voltage Unit 23 Paper Size Selection Switch 24 Synthetic Information Instruction Switch (Synthesis) (Instructing means) 25 Black-and-white / color selection switch 26 Copy start switch 100 Full-color copying machine 101 Photosensitive drum 102 Charging electrode 103 Original placing table 104 Developing unit 104a Yellow toner developing device 105 Copy paper cartridge 106 Paper 107 Transfer drum 108 Transfer electrode 109 Fixing vessel

Front Page Continuation (72) Inventor Takao Ichihashi 1-2-2 Tamatsukuri, Chuo-ku, Osaka City, Osaka Prefecture Mita Industry Co., Ltd.

Claims (2)

[Claims] 1. A synthesizing instruction unit for instructing to synthesize a plurality of original images on one copy sheet, holding the copy sheets, and in proximity to the photoconductor in synchronization with rotation of the photoconductor. And a rotation of the transfer drum, and a voltage is applied at a predetermined timing to transfer the original image formed on the photoconductor onto the copy sheet held on the surface of the transfer drum as the transfer drum rotates. Alternatively, when a transfer electrode to which a current is applied and the instruction from the combining instruction unit are received, when the plurality of document images are sequentially transferred to the one copy sheet, the transfer image is transferred to the one copy sheet. And a transfer electrode control means for controlling the transfer electrode so that the application is not performed in a substantial transfer region of the whole or a part of the original image with respect to the inside original image. Synthetic transfer equipment Place 2. The transfer electrode control means is configured to prevent the voltage from being applied to the transfer electrode in a substantial transfer area of the already transferred original image with respect to the original image being transferred.
The synthetic transfer device according to claim 1, which is controlled.