JP2005107234A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can form images even on the tab of tab paper or the periphery of the punched hole of punched paper, without causing transfer failure. <P>SOLUTION: The image forming apparatus is provided with an operation part for inputting information, showing that recording paper for image formation has a tab or punched hole; and a control value storage part for storing control values which are voltage or current values, for transferring toner image to the tab or to the periphery of the punched hole. When the toner image is transferred to the tab or the periphery of the punched hole, the transfer voltage or the transfer current is switched to the control value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for forming an image on a recording sheet having tabs, punch holes, and the like.

  In the image forming apparatus, a recording paper (hereinafter referred to as “tab paper”) provided with a portion called a tab or an index used for applications such as headings and a punch hole for filing are provided. Recording paper (hereinafter referred to as “punch hole paper”) or the like may be used. A technique for detecting the tab portion of the tab paper and printing the portion, and a technique for detecting the punch hole portion of the punched paper and controlling the printing are already well known (for example, Patent Documents 1 and 2). 3).

  FIG. 9 is a diagram illustrating the periphery of the transfer unit that transfers the toner image onto the recording paper in the image forming apparatus, from the moving direction of the recording paper and the orthogonal direction. In the drawing, a recording paper P and an intermediate transfer belt 104 are pressed so as to be in close contact with each other between a secondary transfer roll 107 and a driven roll 106 to which a potential difference is applied, and an electric field formed in this close contact portion. As a result, the toner image on the intermediate transfer belt 104 is transferred onto the recording paper P. There are constant current control and constant voltage control as a method of performing transfer in the transfer portion. The constant current control is a method in which a constant transfer current is passed between the secondary transfer roll 107 and the driven roll 106 to perform transfer, and the constant voltage control is the transfer between the secondary transfer roll 107 and the driven roll 106. In this method, transfer is performed by applying a constant transfer voltage.

  Here, FIG. 10 is a view showing the state of the transfer surface of the transfer portion at each position of the recording paper when viewed in parallel to the moving direction of the recording paper, and each transfer surface is the recording paper. AA ′ part, BB ′ part and CC ′ part are shown. As shown in the figure, in the tab portion of the tab paper (BB ′ portion in the figure) and the punch hole portion of the punched hole paper (CC ′ portion in the figure), the other portions (in the drawing) Compared with the AA ′ portion), the area of the recording paper P sandwiched between the secondary transfer roll 107 and the driven roll 106 becomes very small. This causes the following problems.

First, in the case of constant current control, a portion where the recording paper P is present has a higher electrical resistance than a portion where the recording paper P is not present, so that more current flows to the portion where the recording paper P is not present. For this reason, the current is relatively reduced in a portion of the recording paper P, and this causes a transfer defect to easily occur between the tab portion or the punch hole.
Next, in the case of constant voltage control, electric resistance is generated by the secondary transfer roll 107, the recording paper P, the intermediate transfer belt 104, and the driven roll 106 against the potential difference generated between the secondary transfer roll 107 and the driven roll 106. Assuming that R ₁ , R ₂ , R ₃ , and R ₄ act, the electrical resistance R ₂ of the recording paper P becomes smaller as the portion with the recording paper P decreases. For this reason, when the transfer is performed between the tab portion or between the punch hole and the punch hole, the electric resistance R ₂ becomes smaller than when the transfer is performed to the other portion. Becomes smaller and transfer defects are likely to occur.

Japanese Patent Laid-Open No. 06-227734 Japanese Patent Laid-Open No. 11-327363 JP 2000-132005 A

  The present invention has been made under such a background, and an object of the present invention is to enable image formation without causing a transfer defect even in a tab portion of a tab paper or a punch hole periphery of a punch hole paper. An image forming apparatus is provided.

In order to solve the above-described problem, an image forming apparatus according to the present invention includes a transfer unit that transfers toner to a recording medium, and a protrusion or notch at least at one end of the recording medium, or the recording medium has a hole. An input means for inputting information indicating that the toner image has a voltage value applied to transfer a toner image to the recording surface around the hole or notch or the recording surface of the protrusion, or a current to be supplied Control value storage means storing a control value as a value; and when the information is input to the input means, the transfer means is controlled in accordance with the control value stored in the control value storage means to the recording medium. Transfer control means for transferring the toner image.
As a result, it is possible to form an image on a recording medium having a protruding portion such as a tab, a hole such as a punch hole, or a notch, without causing a transfer defect.

In a more preferred aspect of the image forming apparatus according to the present invention, the input unit is input with characteristic information characterizing the protruding portion, the notch portion, or the hole portion together with the information. The toner image is transferred to the recording medium by controlling the transfer unit according to the control value corresponding to the feature information.
At this time, the feature information is information indicating an area of the projecting portion, the notch portion, or the hole portion, and the control value varies depending on the feature information.
Alternatively, the feature information is a weight per unit area of the recording medium, and the control value varies depending on the feature information.
According to this aspect, it is possible to perform image formation controlled by a more appropriate control value in accordance with the size of the protrusion, hole, or notch of the recording medium and the basis weight of the recording medium.

In a more preferred aspect, the image forming apparatus according to the present invention further includes a measurement unit that measures temperature or humidity, and the transfer control unit controls the transfer unit according to the control value corresponding to the temperature or humidity. Then, the toner image is transferred to the recording medium.
According to this aspect, it is possible to perform image formation controlled by a more appropriate control value according to temperature and humidity.

  Further, in the image forming apparatus according to the present invention, the control value transfers the toner image to a recording surface other than the recording surface around the hole or notch on the recording medium or to a recording surface other than the protruding portion. It is also possible to indicate the value relative to the value of the applied voltage or the supplied current.

In a more preferred aspect of the image forming apparatus according to the present invention, the transfer control unit includes a recording surface other than the recording surface around the hole or notch on the recording medium, or other than the protruding portion. A change from the value of the voltage applied to transfer the toner image to the recording surface or the value of the supplied current to the control value is performed continuously or stepwise.
More preferably, the transfer control means applies a voltage to transfer a toner image to a recording surface other than the recording surface around the hole or notch on the recording medium or to a recording surface other than the protrusion. Or the value of the current to be supplied is changed to the control value from the periphery of the protrusion or notch or the hole and from the protrusion or notch or a part other than the hole.
More preferably, the transfer control means applies a voltage to transfer a toner image to a recording surface other than the recording surface around the hole or notch on the recording medium or to a recording surface other than the protrusion. Or the value of the supplied current to the control value is terminated at a predetermined portion of the protrusion or notch or the hole.
According to this aspect, the voltage or current is gradually changed around the tabs and punch holes, and image formation can be performed without suddenly changing the image quality.

(1) Configuration FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 according to the present embodiment. Hereinafter, the configuration of the image forming apparatus 1 will be described in detail with reference to FIG. In the figure, a dotted line P indicates a recording paper conveyance path.
The image forming apparatus 1 includes a control unit 100, a control value storage unit 101, image forming units 102Y, 102M, 102C, and 102K, primary transfer rolls 103Y, 103M, 103C, and 103K, an intermediate transfer belt 104, and a drive roll. 105, a plurality of driven rolls 106, a secondary transfer roll 107, a fixing device 108, a plurality of transport rolls 109, recording paper trays 110a, 110b, 110c, and 110d, and an operation unit 111.

The control unit 100 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like, and controls each unit of the image forming apparatus 1 by executing various application programs and arithmetic processing. The control value storage unit 101 stores control values for transfer voltage values and transfer current values under various transfer conditions such as the temperature and humidity inside the image forming apparatus 1 and the basis weight of the recording paper. Reads out a control value corresponding to the above-described transfer condition from the control value storage unit 101, and controls the transfer voltage or transfer current at the time of transfer.
Each of the image forming units 102Y, 102M, 102C, and 102K includes a photosensitive drum, a charging device, an exposure device, a developing device, and the like (not shown), and Y (yellow), M (magenta), C (cyan), and K (black). A toner image of each color is formed. The generated toner images of the respective colors are transferred to the intermediate transfer belt 104 by the primary transfer rolls 103Y, 103M, 103C, and 103K. The intermediate transfer belt 104 is rotationally driven by a drive roll 105, and a plurality of driven rolls 106 are stretched around the intermediate transfer belt 104 and are driven to rotate.
Different types of recording paper are stored in the recording paper trays 110a, 110b, 110c, and 110d, respectively. A plurality of transport rolls 109 transport recording paper.
The secondary transfer roll 107 transfers the toner image formed on the intermediate transfer belt 104 onto the recording paper. The fixing device 108 fixes the toner image on the recording paper to the recording paper by heating and pressing. A portion where the secondary transfer roll 107 transfers the toner image onto the recording paper is hereinafter referred to as a “transfer portion”.
The operation unit 111 includes a liquid crystal panel, a plurality of buttons, and the like, and an operator inputs information such as the type of recording paper and an image forming mode described later.

In addition to the normal rectangular recording paper, the recording paper used in the present embodiment includes tab paper and punched hole paper.
FIG. 2 is a diagram illustrating tab paper and punched hole paper. As shown in the figure, a tab sheet is a recording sheet in which a substantially rectangular protrusion (tab) is provided on one side of the recording sheet, and a punch hole sheet is a recording sheet. The recording paper is provided with a hole (punch hole) in a part of the recording surface. There are various shapes and positions of tabs and punch holes, and the number thereof is also various.

(2) Operation Under such a configuration, the image forming apparatus 1 forms an image on a recording sheet. The image forming apparatus 1 of the present embodiment has two types of image forming modes, “plain paper mode” and “tab paper / punch hole paper mode”. The plain paper mode is an image formation mode that is selected when normal recording paper without tabs or punch holes is used for image formation. The tab paper / punch hole paper mode is an image of recording paper with tabs or punch holes. This is an image forming mode selected when used for forming. The above-mentioned plain paper mode is set as a default in the image forming apparatus. However, when the operator inputs an instruction to form an image on tab paper or punched paper, the image forming mode is set to this tab paper.・ Switch to punched hole paper mode.

In the tab sheet / punch hole paper mode, the image forming apparatus 1 transfers the transfer voltage applied or the transfer current value supplied to transfer the toner image onto the recording sheet to the tab portion or the punch hole peripheral portion. And in other cases.
As described with reference to FIG. 10, the area of the recording paper sandwiched between the secondary transfer roll 107 and the driven roll 106 is very small in the tab portion or the peripheral portion of the punch hole as compared with other portions. For this reason, in the constant voltage control, the transfer voltage applied to the recording paper decreases, and in the constant current control, the current flowing through the recording paper portion decreases. In order to compensate for the decrease in the transfer voltage or the decrease in the transfer current, when transferring the tab portion or the peripheral portion of the punch hole, the transfer is performed with a transfer voltage or transfer current higher than that of the other portions. Hereinafter, this operation will be described in more detail.

When the image forming mode of the image forming apparatus 1 is switched to the tab sheet / punch perforated sheet mode, the operator instructs the mode switching and inputs various information. The information is information indicating the number of tabs, basis weight, or tab position, which will be described later. Further, the image forming apparatus 1 constantly monitors the temperature and humidity inside the apparatus, and this information is also supplied to the control unit 100 of the image forming apparatus 1 as appropriate. Hereinafter, these pieces of information are collectively referred to as “input information”.
When the input information described above is supplied, the control unit 100 reads the transfer condition corresponding to the input information from the control value storage unit 101, and determines the transfer voltage applied to the transfer unit or the supplied transfer current according to the transfer condition. Control.

  In the following, three examples will be shown for the case where the image forming apparatus 1 performs transfer by changing the transfer voltage with respect to the tab portion of the tab sheet, and the results of experiments conducted according to these examples are shown. In these embodiments, it is assumed that the recording paper is transported such that the tab-attached side is orthogonal to the recording paper transport direction.

(2-1) Example 1
In this embodiment, the image forming apparatus 1 changes the transfer voltage value at the tab portion according to the total number of tabs at the time of transfer, that is, the size of the tabs.
FIG. 3 is a diagram illustrating three types of tab sheets used in this embodiment. As shown in the figure, in this embodiment, tab sheets having 5, 7, and 10 tabs are used, and when transferring is performed on the tab portions of the respective tab sheets, different transfer voltages are applied.

As already described, the transfer voltage decreases as the portion of the recording paper decreases during transfer. That is, as the number of tabs increases and the size of each tab decreases, the degree of decrease in transfer voltage increases.
Therefore, the applicant conducted the experiment shown below and found the optimum control value of the transfer voltage of the tab portion in the recording paper of each number of tabs.

In the experiment in this embodiment, for three types of tab sheets having 5, 7, and 10 tabs, the transfer voltage when the toner image is transferred to the tab portion is stepped from the initial value (transfer voltage of the portion other than the tab). The voltage value at which a print result equivalent to the portion other than the tab was obtained was obtained. The recording paper used in the experiment had a basis weight of 270 g / m ² and the experimental environment was a standard environment (temperature 22 ° C., humidity 55%).
FIG. 4 is a table showing voltage values (control values) at the respective tab numbers. The voltage value shown in the figure is shown as a relative value with respect to the initial value described above. In other words, in the case of a tab sheet with the number of tabs being “5”, this experimental result is equivalent to the portion other than the tab by applying a transfer voltage 1.4 times the transfer voltage of the portion other than the tab. It is shown that the print result is obtained.

Thus, as the number of tabs increases and the size of each tab decreases, the transfer voltage decreases, and it is necessary to increase the transfer voltage more in order to obtain a print result equivalent to the portion other than the tab at the tab portion. It was confirmed.
Further, by storing the value shown in FIG. 4 in the control value storage unit 101 as a control value, the image forming apparatus 1 causes a transfer failure even for the tab portion of the tab sheet used in the above-described experiment. Thus, it is possible to form an image in the same manner as the portion other than the tab. Similarly, the control value of the transfer voltage is obtained for tab sheets having tab portions of various modes, and this is stored in the control value storage unit 101, whereby the image forming apparatus 1 uses the tab sheets having various tabs. Similarly, it is possible to form an image.

(2-2) Example 2
Subsequently, in this embodiment, the image forming apparatus 1 changes the transfer voltage value at the tab portion according to the type of recording paper, specifically, the basis weight of the recording paper.
In general, the larger the basis weight of recording paper, the greater the electrical resistance during transfer. That is, the larger the basis weight, the larger the difference in transfer voltage between the tab portion and the portion other than the tab.
Therefore, the applicant conducted an experiment shown below to obtain an optimum control value of the transfer voltage of the tab portion in the recording paper of each basis weight.

In the experiment in this embodiment, for three types of tab sheets having a basis weight of 120, 210, and 270 (g / m ² ), the transfer voltage when transferring the toner image to the tab portion is set to the initial value (the portion other than the tab). The voltage value at which a printing result equivalent to that of the portion other than the tab was obtained was obtained in a stepwise manner from the transfer voltage. The number of tabs of the recording paper used in the experiment was 5, and the experiment environment was a standard environment (temperature 22 ° C., humidity 55%).
FIG. 5 is a table showing voltage values (control values) at respective basis weights. The voltage value shown in the figure is shown as a relative value with respect to the initial value described above. In other words, in the case of a tab sheet having a basis weight of “120 g / m ² ”, this experimental result shows that a transfer voltage of 1.1 times the transfer voltage of a portion other than the tab is applied to the tab portion. It shows that the printing result equivalent to the part was obtained.

As described above, it is confirmed that the transfer voltage is decreased as the basis weight is increased, and it is necessary to increase the transfer voltage more in order to obtain a print result equivalent to the portion other than the tab at the tab portion.
Further, by storing the value shown in FIG. 5 in the control value storage unit 101 as a control value, the image forming apparatus 1 causes a transfer defect even for the tab portion of the tab sheet used in the above-described experiment. Thus, it is possible to form an image in the same manner as the portion other than the tab. Similarly, the control values of the transfer voltage are obtained for tab sheets of various basis weights and stored in the control value storage unit 101, so that the image forming apparatus 1 similarly applies to tab sheets of various basis weights. Thus, image formation can be performed.

(2-3) Example 3
Finally, in this embodiment, the image forming apparatus 1 changes the transfer voltage value at the tab portion according to the temperature and humidity inside the apparatus.
In general, the electric resistance of paper depends on temperature and humidity, and becomes high resistance at low temperature and low humidity, and low resistance at high temperature and high humidity. That is, as the environment becomes lower in temperature and humidity, the difference in transfer voltage between the tab portion of the tab sheet and the portion other than the tab increases.
Therefore, the applicant conducted an experiment shown below and obtained an optimum control value of the transfer voltage of the tab portion in different environments.

In the experiment in the present embodiment, there are three kinds of environments: a low temperature and low humidity environment (temperature 10 ° C., humidity 15%), a standard environment (temperature 22 ° C., humidity 55%), and a high temperature high humidity environment (temperature 28 ° C., humidity 85%). In step 1, the transfer voltage when the toner image is transferred to the tab part is changed stepwise from the initial value (transfer voltage of the part other than the tab), and the print result equivalent to the part other than the tab is obtained. The voltage value obtained was determined. The number of tabs of the recording paper used in the experiment was 5, and the basis weight was 270 (g / m ² ).
FIG. 6 is a table showing voltage values (control values) in each environment. The voltage value shown in the figure is shown as a relative value with respect to the initial value described above. In other words, the results of this experiment show that when an image is formed on a tab sheet in a low temperature and low humidity environment, a transfer voltage of 1.5 times the transfer voltage of the portion other than the tab is applied to the tab portion. It shows that an equivalent print result was obtained.

In this way, it was confirmed that the transfer voltage at the tab portion decreased as the environment became lower in temperature and humidity, and it was necessary to increase the transfer voltage more to obtain the same print result as the portion other than the tab at the tab portion. .
Further, by storing the value shown in FIG. 6 in the control value storage unit 101 as a control value, the image forming apparatus 1 causes a transfer failure even for the tab portion of the tab sheet used in the above-described experiment. Thus, it is possible to form an image in the same manner as the portion other than the tab. Similarly, the control value of the transfer voltage is obtained in various environments and is stored in the control value storage unit 101, so that the image forming apparatus 1 performs image formation in the same manner in other various environments. Is possible.

(3) Modifications The embodiment of the present invention has been described with reference to three examples. However, the present invention can be implemented without being limited to the above-described embodiment. An example is shown below.
First, in the above-described embodiment, the image forming apparatus 1 having the configuration shown in FIG. 1 has been described. However, the application of the present invention is not limited to the image forming apparatus having this configuration. For example, an image forming apparatus using a sheet conveying belt may be used instead of the intermediate transfer belt 104 shown in the figure, and of course, an image forming apparatus using another intermediate transfer member may be used. 1 has a so-called tandem configuration in which the four color image forming units 102Y, 102M, 102C, and 102K are arranged along the intermediate transfer belt 104. However, the image forming apparatus 1 is not limited to this, and an image having a multi-cycle configuration. It is of course possible to apply the present invention to the forming apparatus.
In the above-described embodiment, information indicating the number of tabs, the basis weight, or the tab position is input from the operation unit 111 by the operator. For example, the information is input to the recording paper trays 110a, 110b, 110c, and 110d. It is also possible to provide means for inputting the above information so that the information can be input when tab paper or punched paper is set on the recording paper tray.

In the above-described embodiment, the recording medium on which an image is formed is limited to recording paper. Of course, other recording media, for example, plastics such as an OHP film, various materials such as wood and cloth are used. It is possible.
In the above-described embodiment, the tab sheet and punched hole paper are described as examples. However, the application of the present invention is not limited to these recording media. For example, a recording medium having both a tab and a punch hole can be used. In addition, it is also possible to use a recording medium having a shape obtained by cutting out or cutting out a part of a normal rectangular recording paper. That is, the recording media that are effective by the application of the present invention are all recording media in which the area of the recording medium in contact with the transfer body on the transfer surface changes greatly during a series of image forming processes. Therefore, the recording medium used in the image forming apparatus according to the present invention has a recording medium having a protrusion such as a tab at least one end, or a recording medium having a hole such as a punch hole. I just need it. In contrast to the protruding shape such as the protruding portion, as shown in FIG. 7, a notched portion having a notched shape at least at one end of the recording medium may be provided. Of course, such a protrusion, notch, or hole may have any shape, and a recording medium having a plurality of different protrusions, notches, or holes may be used.

Further, in the above-described three embodiments, it has been described that the transfer is performed with the voltage values shown in FIGS. However, if the difference between the voltage value at the tab portion and the initial value (transfer voltage at the portion other than the tab) is large, the image quality may change abruptly at the transfer voltage switching portion. Therefore, it is desirable that the transfer voltage is switched continuously or stepwise from the portion without the tab, and the change is terminated when the tab portion is entered.
FIG. 8 is a diagram showing changes in the transfer voltage when transferring the tab paper and punched paper. Points P _{1 to} P ₃ and points Q _{1 to} Q ₄ on the graph correspond to the positions of the same symbols shown on the tab paper and punch hole paper, respectively.
As shown in the figure, the change from the voltage V ₁ to V ₂ continuously changes before and after the point P ₂ . Similarly, changes from the voltage V ₃ to the voltage V ₄ or the voltage V ₃ from the voltage V _4, is continuously changed before and after the point Q ₂ or point Q _3. When the transfer voltage reaches V ₂ to V ₄ , that is, the control value, the change of the transfer voltage is stopped. By doing so, it is possible to prevent a change in image quality due to a sudden change in the transfer voltage at the transfer voltage switching portion, that is, around the point P ₂ , the point Q ₂ , and the point Q _{3 in} the drawing.

In the above-described three embodiments, the transfer voltage is controlled. However, the transfer current may be controlled. Furthermore, although all the above-mentioned three embodiments have been described with respect to the case of transferring to the tab portion of the tab paper, the present invention can also be applied to the case of transferring to the punch hole paper in the same manner.
In the above-described three embodiments, the voltage value is shown as a relative value with respect to the initial value. However, an actual voltage value may be stored in the control value storage unit 101.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is the figure which illustrated the tab paper and punch hole paper in the embodiment. It is the figure which illustrated tab paper used in the 1st example of the embodiment. It is the table | surface which showed the voltage value in each tab number in the Example. It is the table | surface which showed the voltage value in each basic weight in the 2nd Example of the embodiment. It is the table | surface which showed the voltage value in each environment in the 3rd Example of the embodiment. It is the figure which illustrated the recording medium provided with the notch part. It is a figure showing change of transfer voltage at the time of transfer of tab paper and punch hole paper, respectively. FIG. 4 is a diagram illustrating a periphery of a transfer unit from a moving direction of a recording sheet and a direction orthogonal thereto. FIG. 6 is a diagram illustrating a state of a transfer surface of a transfer unit at each position of a recording sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 100 ... Control part, 101 ... Control value memory | storage part, 102Y, 102M, 102C, 102K ... Image forming unit, 103Y, 103M, 103C, 103K ... Primary transfer roll, 104 ... Intermediate transfer belt, 105 ... Drive roll, 106 ... driven roll, 107 ... secondary transfer roll, 108 ... fixing device, 109 ... transport roll, 110a, 110b, 110c, 110d ... recording paper tray, 111 ... operation unit.

Claims (9)

Transfer means for transferring toner to a recording medium;
An input means for inputting information indicating that the recording medium has a protrusion or notch at at least one end of the recording medium, or that the recording medium has a hole;
Control value storage means for storing a control value which is a value of a voltage to be applied or a value of a current to be supplied to transfer a toner image to a recording surface around the hole or notch or the recording surface of the protrusion;
An image forming apparatus comprising: a transfer control unit configured to control the transfer unit according to the control value stored in the control value storage unit to transfer a toner image onto the recording medium when the information is input to the input unit; . Characteristic information characterizing the protrusion or notch or the hole is input to the input means together with the information,
The image forming apparatus according to claim 1, wherein the transfer control unit controls the transfer unit according to the control value corresponding to the feature information to transfer a toner image onto the recording medium. Equipped with measuring means to measure temperature or humidity,
The image forming apparatus according to claim 1, wherein the transfer control unit controls the transfer unit according to the control value corresponding to the temperature or humidity to transfer a toner image onto the recording medium. The control value is a value of a voltage applied to transfer a toner image to a recording surface other than the recording surface around the hole or notch on the recording medium, or a recording surface other than the protrusion, or a current to be supplied. The image forming apparatus according to claim 1, wherein the image forming apparatus is represented by a relative value with respect to the value of. The characteristic information is information indicating an area of the protruding portion or the notch portion or the hole portion,
The image forming apparatus according to claim 2, wherein the control value varies depending on the feature information. The characteristic information is a weight per unit area of the recording medium,
The image forming apparatus according to claim 2, wherein the control value varies depending on the feature information. The transfer control means is a voltage value or supply applied to transfer a toner image to a recording surface other than the recording surface around the hole or notch on the recording medium, or to a recording surface other than the protrusion. The image forming apparatus according to claim 1, wherein a change from a current value to the control value is performed continuously or stepwise. The transfer control means is a voltage value or supply applied to transfer a toner image to a recording surface other than the recording surface around the hole or notch on the recording medium, or to a recording surface other than the protrusion. The change from the value of the current to the control value is started from the periphery of the protrusion or notch or the hole and from the protrusion or notch, or a part other than the hole. Image forming apparatus. The transfer control means is a voltage value or supply applied to transfer a toner image to a recording surface other than the recording surface around the hole or notch on the recording medium, or to a recording surface other than the protrusion. The image forming apparatus according to claim 1, wherein the change from the current value to the control value is terminated at a predetermined portion of the protrusion or notch or the hole.

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