JP2015191018A - image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can reduce stains on a recording target medium due to a toner moved from a separation member to a heating roller.SOLUTION: An image forming apparatus 1 includes a heating roller 121, pressure roller 122, and separation member 123. The heating roller 121 and pressure roller 122 are rotatable and hold a sheet P to thermally fix a toner image to the sheet P. The separation member 123 is arranged to contact the heating roller 121. The separation member 123 is a member to separate the sheet P from the heating roller 121. When images are continuously formed on the plurality of sheets P, the rotations of the heating roller 121 and pressure roller 122 are suspended at least once.

Description

  The present invention relates to an image forming apparatus.

  Image forming apparatuses such as printers and copiers that employ an electrophotographic system form an image on a recording medium such as paper based on image data. The image data is created, for example, by an image forming apparatus reading a document placed on a document table. In general, an electrophotographic image forming apparatus presses and heats a recording medium with a heating roller and a pressure roller to fix an unfixed toner image on the recording medium. In addition, the electrophotographic image forming apparatus generally includes a separation member provided so that the tip of the heating roller is in contact with the heating roller. The separating member is provided to prevent the recording medium from being wound around the heating roller.

  In the image forming apparatus having such a configuration, the toner that has not been fixed to the recording medium may adhere to the separation member. When images are continuously formed on a plurality of recording media, Toner is accumulated. The toner accumulated on the separation member moves onto the heating roller when the next print job is executed. For this reason, the toner on the heating roller may adhere to the recording medium and stain the recording medium. Therefore, in the image forming apparatus described in Patent Document 1, the separation member cleaning device is used to clean the separation member and reduce the amount of toner accumulated in the separation member.

JP 2001-022218 A

  However, the image forming apparatus described in Patent Document 1 requires a mechanism for cleaning the separating member, and the configuration of the image forming apparatus is complicated. In addition, a space for providing a mechanism for cleaning the separation member is required, resulting in an increase in the size of the image forming apparatus.

  The present invention has been made in view of the above problems, and can reduce contamination of a recording medium due to toner moved on a rotating member such as a heating roller provided in a fixing device without using a separation member cleaning device. An object is to provide an image forming apparatus.

  An image forming apparatus according to the present invention includes an image forming unit, a pair of rotating members, a separating member, and a control unit. The image forming unit forms a toner image on a recording medium. The pair of rotating members are rotatable, sandwich the recording medium, and thermally fix the toner image on the recording medium. The separation member is disposed so as to contact one of the pair of rotating members. The separation member is a member for separating the recording medium from one of the pair of rotating members. The controller temporarily stops the rotation of the pair of rotating members at least once when images are continuously formed on the plurality of recording media.

  According to the image forming apparatus of the present invention, it is possible to reduce the contamination of the recording medium due to the toner moved to one of the pair of rotating members without using the separation member cleaning device.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a fixing unit according to an embodiment of the present invention. It is a figure which shows the relationship between the separating member which concerns on embodiment of this invention, and a paper. 1 is a block diagram of an image forming apparatus according to Embodiment 1 of the present invention. 3 is a flowchart illustrating an operation of the image forming apparatus according to the first exemplary embodiment of the present invention. FIG. 4 is a diagram illustrating a relationship between a fixing unit and toner according to an exemplary embodiment of the present invention. FIG. 5 is a block diagram of an image forming apparatus according to Embodiments 2 and 3 of the present invention. 6 is a flowchart illustrating an operation of the image forming apparatus according to the second exemplary embodiment of the present invention. 10 is a flowchart illustrating an operation of the image forming apparatus according to the third exemplary embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

[Embodiment 1]
The configuration of the image forming apparatus 1 will be described with reference to FIG. FIG. 1 is a diagram showing an outline of the configuration of the image forming apparatus 1. The image forming apparatus 1 can be a copying machine, a printer, a facsimile machine, or a multifunction machine having these functions.

  The image forming apparatus 1 includes an image forming unit 10, a control unit 20, a paper feeding unit 30, a transport unit 40, and a discharge unit 50.

  The image forming unit 10 forms an image on a recording medium based on the image data. In the present embodiment, the image forming unit 10 includes an image forming unit 110 and a fixing unit 120. The recording medium is paper P. The paper P can be plain paper, cardboard, or glossy paper.

  The image forming unit 110 forms a toner image on the paper P. The image forming unit 110 includes a plurality of photoconductors 111, a plurality of developing devices 112, a transfer device 113, and an exposure device 114. Each of the plurality of developing devices 112 is arranged corresponding to each photoconductor 111.

  The exposure device 114 exposes each photoconductor 111 by irradiating it with a laser beam, and forms an electrostatic latent image on each photoconductor 111. Each photoconductor 111 carries an electrostatic latent image and a toner image. Each developing device 112 supplies toner to the corresponding photoconductor 111 to develop the electrostatic latent image. Thereby, a toner image is formed on each photoconductor 111. Each developing device 112 is supplied with toner from a corresponding toner supply device 115.

  The transfer device 113 transfers the toner image formed on each photoconductor 111 so as to overlap the paper P.

  The fixing unit 120 includes a heating roller 121 and a pressure roller 122 which are an example of a pair of rotating members. The fixing unit 120 fixes the unfixed toner image formed on the paper P in the image forming unit 110 to the paper P.

  The control unit 20 has a storage area. The storage area stores programs and setting information. The storage area is composed of a RAM (Random Access Memory) and a ROM (Read Only Memory). The control unit 20 controls the overall operation of the image forming apparatus 1 by executing various control programs stored in advance in the ROM.

  The paper feed unit 30 accommodates a plurality of sheets P and feeds the paper P to the transport unit 40. The paper feed unit 30 includes a plurality of paper feed roller groups 31 and a plurality of paper feed cassettes 32. Each of the plurality of paper feed roller groups 31 is arranged corresponding to each paper feed cassette 32. The plurality of paper feed roller groups 31 take out the paper P stored in the corresponding paper feed cassette 32 one by one and feed it to the transport unit 40.

  The transport unit 40 transports the paper P to the discharge unit 50 via the image forming unit 110 and the fixing unit 120. The discharge unit 50 discharges the paper P outside the apparatus.

  Next, the fixing unit 120 will be described in detail with reference to FIG. FIG. 2 is a diagram illustrating the fixing unit 120.

  As shown in FIG. 2, the fixing unit 120 further includes a separation member 123 and a thermistor 124 in addition to the heating roller 121 and the pressure roller 122. The heating roller 121 and the pressure roller 122 are rotatable around their respective rotation axes. The heating roller 121 is disposed to face the pressure roller 122, and the paper P is sandwiched between the heating roller 121 and the pressure roller 122 and conveyed in the paper conveyance direction D1. The heating roller 121 rotates in a rotation direction D2 (counterclockwise direction on the paper surface) by a driving source. A heat source H that heats the heating roller 121 is disposed inside the heating roller 121. The pressure roller 122 follows the heating roller 121 and rotates in the rotation direction D3 (clockwise direction on the paper surface).

  The heating roller 121 and the pressure roller 122 are pressed against each other, and a nip portion N is formed between the heating roller 121 and the pressure roller 122. An unfixed toner image made of toner T is formed on the paper P before passing through the nip portion N. As the paper P passes through the nip portion N and is heated and pressurized, the toner image (toner T) is fixed on the paper P. In the present embodiment, a case where a toner image is formed on one side of the paper P (hereinafter referred to as a printing surface Ps) will be described. When the paper P passes through the nip portion N, the printing surface Ps faces the peripheral surface of the heating roller 121.

  The separation member 123 is arranged so that the tip thereof is in contact with the peripheral surface of the heating roller 121. The separation member 123 separates the paper P from the heating roller 121 when the paper P that has passed through the nip portion N tries to wind around the heating roller 121. At this time, the printing surface Ps of the paper P comes into contact with the leading end of the separation member 123.

  The thermistor 124 detects the surface temperature of the heating roller 121. The heat source H is controlled based on the temperature detected by the thermistor 124.

  Next, the relationship between the separating member 123 and the paper P will be described with reference to FIG. FIG. 3 is a diagram illustrating the relationship between the separation member 123 and the paper P, as viewed from the printing surface Ps side of the paper P.

  As shown in FIG. 3, in the present embodiment, the number of separation members 123 is four, and the tips of the separation members 123 are in contact with the heating roller 121 in four regions included in the peripheral surface of the heating roller 121. Therefore, there is a possibility that the printing surface Ps of the paper P may come into contact with the front end of each separation member 123 at positions corresponding to the four contact areas where the front end of each separation member 123 and the peripheral surface of the heating roller 121 come into contact. Hereinafter, a region facing the contact region where the separation member 123 and the heating roller 121 are in contact with each other on the printing surface Ps (a region corresponding to the separation member 123 in the paper P) is referred to as a facing region 501. The print surface Ps may come into contact with the tip of the separation member 123 in the facing region 501. The number of areas that may come into contact with the leading end of the separation member 123 on the printing surface Ps varies depending on the width of the paper P. Here, a case will be described in which the four regions included in the printing surface Ps of the paper P may come into contact with the leading ends of the corresponding separation members 123, respectively. In this case, the facing region 501 is a region obtained by combining four regions that may come into contact with the separation member 123.

  Next, with reference to FIG. 4, the control unit 20 provided in the image forming apparatus 1 will be described in detail.

  The control unit 20 includes an image processing control unit 210 and a print control unit 220. The image processing control unit 210 includes a calculation unit 211, a determination unit 212, a counting unit 213, a determination unit 214, and an initialization unit 215.

  The calculation unit 211 calculates the image density D of the image formed in the facing area 501 (see FIG. 3) on the paper P based on the image data. Specifically, the image density D is obtained by the following formula 1.

D = Sd / Sg (Formula 1)
Sd indicates the area of the image formed in the facing region 501 of one sheet of paper P. Sg indicates the area of the facing region 501 of one sheet of paper P. For example, the image data is input to the control unit 20 from an external PC client. Alternatively, the control unit 20 creates image data based on a signal generated by scanning a document placed on the document table. Alternatively, the control unit 20 creates image data based on a signal generated by scanning a document sent by the automatic document feeder.

  The determination unit 212 determines a threshold value according to the image density D. For example, a table in which the image density is associated with the threshold value may be stored in the storage area, and the determination unit 212 may determine the threshold value using the table. The contents of the table can be set arbitrarily. For example, a table having a threshold value corresponding to an image density of 5% to less than 10% is set to 1000 and a threshold value corresponding to an image density of 10% to less than 20% is stored in the storage area. When the image density D calculated by the calculation unit 211 is 5%, the determination unit 212 compares the image density D (5%) with the contents of this table and determines 1000 as the threshold value. The determination unit 212 determines a smaller threshold value as the image density D increases. Note that an expression defining the relationship between the image density and the threshold value may be stored in the storage area, and the determination unit 212 may determine the threshold value using this expression.

  The counting unit 213 sequentially counts the number of sheets P every time an image is formed.

  The determination unit 214 compares the count result by the count unit 213 with the threshold value determined by the determination unit 212 each time the count result by the count unit 213 changes, and determines whether the count result matches the threshold value. .

  The initialization unit 215 initializes the count result (count value N) of the count unit 213 every time the count result by the count unit 213 matches the threshold value.

  The print control unit 220 controls the image forming operation of the image forming apparatus 1. In the present embodiment, the processing by the print control unit 220 includes processing for temporarily stopping the rotation of the heating roller 121 and the pressure roller 122 (see FIG. 2) under a predetermined condition. Specifically, the print control unit 220 temporarily stops the rotation of the heating roller 121 and the pressure roller 122 while stopping the conveyance operation of the paper P by the conveyance unit 40.

  Next, the operation of the image forming apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the image forming apparatus 1. Specifically, the flowchart of FIG. 5 shows the operation of the image forming apparatus 1 when there is one document. The image forming apparatus 1 forms an image on the paper P by executing steps S602 to S618. In the present embodiment, the operation of the image forming apparatus 1 will be described by taking as an example a case where a document is placed on a document table.

  Step S602: The control unit 20 creates image data based on a signal generated by scanning a document placed on a document table.

  Step S604: The calculation unit 211 calculates the image density D based on the image data.

  Step S606: The determination unit 212 determines a threshold according to the image density D.

  Step S608: The count unit 213 increments the count value N by 1 each time image forming processing is performed on one sheet of paper P.

  Step S610: The determination unit 214 determines whether or not the count value N matches the threshold value determined by the determination unit 212. If the number of sheets P on which an image is formed (count value N) matches the threshold value (step S610: Yes), the process proceeds to step S612. On the other hand, when the number of sheets P on which an image is formed does not match the threshold (step S610: No), the process proceeds to step S616.

  Step S612: The initialization unit 215 initializes the count value N.

  Step S614: The printing control unit 220 stops the conveyance operation of the paper P by the conveyance unit 40, and temporarily stops the rotation of the heating roller 121 and the pressure roller 122. After temporarily stopping the rotation of the heating roller 121 and the pressure roller 122, the process proceeds to step S616 (the conveyance operation of the paper P by the conveyance unit 40 is resumed, and the rotation of the heating roller 121 and the pressure roller 122 is resumed). ) Note that the order of step S612 and step S614 can be interchanged.

  Step S616: The print control unit 220 controls each unit of the image forming apparatus 1 so as to form an image.

  Step S618: The control unit 20 determines whether or not the image forming process (print job) is completed. If it is determined that the image forming process has ended (step S618: Yes), the process ends. On the other hand, when it is not determined that the image forming process has been completed (step S618: No), the process returns to step S608.

  Next, the movement of the toner T when the rotation of the heating roller 121 and the pressure roller 122 is temporarily stopped will be described with reference to FIG. As shown in FIG. 6A, the toner T that has not been fixed on the paper P may adhere to the separation member 123, and when images are continuously formed on a plurality of papers P, separation is performed. The toner T is accumulated in the member 123.

  When the rotation of the heating roller 121 and the pressure roller 122 is resumed after the rotation of the heating roller 121 and the pressure roller 122 is temporarily stopped, as shown in FIG. 6B, the toner T attached to the separation member 123. However, it moves from the separating member 123 to the heating roller 121. This is because the dynamic friction coefficient is smaller than the static friction coefficient. In the present embodiment, if the count result (count value N) of the counting unit 213 matches the threshold value during the process of continuously forming images on a plurality of sheets P (during execution of a print job), the print control unit 220 The rotation of the heating roller 121 and the pressure roller 122 is temporarily stopped. Therefore, the toner T accumulated in the separation member 123 moves from the separation member 123 to the heating roller 121 in a small amount. As a result, the stain on the paper P due to the toner T moved to the heating roller 121 becomes inconspicuous. That is, in a state where toner T (amount of toner T determined by the threshold) that does not make the paper P dirty is accumulated in the separation member 123, the toner T attached to the separation member 123 is moved to the heating roller 121, Further, the sheet P is moved.

  The first embodiment has been described above. According to the first embodiment, the amount of toner T accumulated in the separation member 123 can be suppressed. Accordingly, it is possible to reduce the contamination of the paper P due to the toner T moved from the separation member 123 to the heating roller 121. That is, the toner T accumulated in the separation member 123 can be moved to the paper P by an amount that does not make the paper P dirty.

[Embodiment 2]
Next, the operation of the image forming apparatus 1 according to the second embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 7 and 8. The second embodiment and the first embodiment are different in conditions for temporarily stopping the rotation of the heating roller 121 and the pressure roller 122. Hereinafter, matters different from the first embodiment will be described with respect to the second embodiment, and descriptions of matters overlapping with the first embodiment will be omitted.

  As illustrated in FIG. 7, the image processing control unit 210 includes a calculation unit 211, a determination unit 214, an initialization unit 215, and an addition unit 216.

  The addition unit 216 repeatedly adds the image density D calculated by the calculation unit 211 each time image formation is performed on one sheet of paper P, thereby calculating an addition value Ad.

  Each time the addition value Ad changes, the determination unit 214 compares the addition value Ad with the threshold value determined by the determination unit 212 and determines whether or not the addition value Ad is equal to or greater than the threshold value.

  The initialization unit 215 initializes the addition value Ad every time the addition value Ad becomes equal to or greater than the threshold value.

  Next, the operation of the image forming apparatus 1 according to the second embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the operation of the image forming apparatus 1. Specifically, the flowchart of FIG. 8 shows the operation of the image forming apparatus 1 when there is one document. The image forming apparatus 1 forms an image on the paper P by executing steps S702 to S716. In the present embodiment, the operation of the image forming apparatus 1 will be described by taking as an example a case where a document is placed on a document table.

  Step S702: The control unit 20 creates image data based on a signal generated by scanning a document placed on a document table.

  Step S704: The calculation unit 211 calculates the image density D based on the image data.

  Step S706: The addition unit 216 sequentially obtains the addition value Ad of the image density D every time the image forming process is performed on one sheet of paper P. The addition value Ad is obtained by repeatedly adding the same value (image density D). That is, the added value Ad corresponds to an integrated value of the number of times of image formation and the image density.

  Step S708: The determination unit 214 determines whether or not the addition value Ad is greater than or equal to a threshold value. When the addition value Ad is equal to or greater than the threshold (step S708: Yes), the process proceeds to step S710. On the other hand, when the addition value Ad is less than the threshold value (step S708: No), the process proceeds to step S714. The threshold value may be set in advance by the user or may be a specified value.

  Step S710: The initialization unit 215 initializes the addition value Ad.

  Step S712: The print control unit 220 stops the conveyance operation of the paper P by the conveyance unit 40, and temporarily stops the rotation of the heating roller 121 and the pressure roller 122. After temporarily stopping the rotation of the heating roller 121 and the pressure roller 122, the process proceeds to step S714 (the conveyance operation of the paper P by the conveyance unit 40 is resumed and the rotation of the heating roller 121 and the pressure roller 122 is resumed). ) Note that the order of step S710 and step S712 can be interchanged.

  Step S714: The print control unit 220 controls each unit of the image forming apparatus 1 so as to form an image.

  Step S716: The control unit 20 determines whether or not the image forming process (print job) has ended. If it is determined that the image forming process has been completed (step S716: Yes), the process ends. On the other hand, if it is not determined that the image forming process has been completed (step S716: No), the process returns to step S706.

The second embodiment has been described above. According to the second embodiment, as in the first embodiment, during the process of continuously forming images on a plurality of sheets P, the rotation of the heating roller 121 and the pressure roller 122 is temporarily stopped to cause the separation member 123 to move. The amount of accumulated toner can be suppressed. Accordingly, it is possible to reduce the contamination of the paper P due to the toner T moved from the separation member 123 to the heating roller 121.
[Embodiment 3]
Next, the operation of the image forming apparatus 1 according to the third embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 7 and 9. The third embodiment and the first embodiment are different in that there are a plurality of documents. Hereinafter, matters different from the first embodiment will be described with respect to the third embodiment, and descriptions of matters overlapping with the first embodiment will be omitted.

  As illustrated in FIG. 7, the image processing control unit 210 includes a calculation unit 211, a determination unit 214, an initialization unit 215, and an addition unit 216.

  The adding unit 216 sequentially adds the image densities D calculated by the calculating unit 211 in the order in which the images are formed to obtain an added value Ad. Note that the newly obtained addition value Ad is added to the addition value Ad that is the sum of the image densities D of the images that have been continuously formed (images in the opposing region 501), and the next image to be formed (in the opposing region 501). The image density D of (image) can be obtained by addition.

  Each time the addition value Ad changes, the determination unit 214 compares the addition value Ad with the threshold value determined by the determination unit 212 and determines whether or not the addition value Ad is equal to or greater than the threshold value.

  The initialization unit 215 initializes the addition value Ad every time the addition value Ad becomes equal to or greater than the threshold value.

  Next, the operation of the image forming apparatus 1 according to the third embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing the operation of the image forming apparatus 1. Specifically, the flowchart of FIG. 9 shows the operation of the image forming apparatus 1 when there are a plurality of documents. The image forming apparatus 1 forms an image on a plurality of sheets P by executing steps S802 to S816. In the present embodiment, the operation of the image forming apparatus 1 will be described by taking as an example a case where image data corresponding to a plurality of documents is input from an external client PC to the control unit 20.

  Step S802: A plurality of image data is input to the control unit 20.

  Step S804: The calculation unit 211 calculates the image density D based on each image data.

  Step S806: The addition unit 216 sequentially obtains the addition value Ad of the image density D in the order in which images are formed each time the image forming process is performed on one sheet of paper P.

  Step S808: The determination unit 214 determines whether or not the addition value Ad is greater than or equal to a threshold value. When the addition value Ad is equal to or greater than the threshold (step S808: Yes), the process proceeds to step S810. On the other hand, when the addition value Ad is less than the threshold value (step S808: No), the process proceeds to step S814. The threshold value may be set in advance by the user or may be a specified value.

  Step S810: The initialization unit 215 initializes the addition value Ad.

  Step S812: The print control unit 220 stops the conveyance operation of the paper P by the conveyance unit 40, and temporarily stops the rotation of the heating roller 121 and the pressure roller 122. After temporarily stopping the rotation of the heating roller 121 and the pressure roller 122, the process proceeds to step S814 (the conveyance operation of the paper P by the conveyance unit 40 is resumed, and the rotation of the heating roller 121 and the pressure roller 122 is resumed). ) Note that the order of step S810 and step S812 can be interchanged.

  Step S814: The print control unit 220 controls each unit of the image forming apparatus 1 so as to form an image.

  Step S816: The control unit 20 determines whether or not the image forming process (print job) has ended. If it is determined that the image forming process has ended (step S816: Yes), the process ends. On the other hand, if it is not determined that the image forming process has been completed (step S816: No), the process returns to step S806.

  The third embodiment has been described above. According to the third embodiment, the rotation of the heating roller 121 and the pressure roller 122 is temporarily stopped and accumulated in the separation member 123 during the process of continuously forming images on a plurality of sheets P, as in the first embodiment. The amount of toner to be reduced can be suppressed. Accordingly, it is possible to reduce the contamination of the paper P due to the toner T moved from the separation member 123 to the heating roller 121.

  The embodiment of the present invention has been described above with reference to the drawings (FIGS. 1 to 9). However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof.

  For example, in the above embodiment, the number of separation members 123 is four, but the number of separation members 123 is not particularly limited, and one or more separation members 123 may be provided.

  In the above-described embodiment, the case where the counter area 501 includes four areas has been described. However, depending on the size of the paper P, the counter area 501 includes fewer than four areas.

  Moreover, although the said embodiment demonstrated the case where the width | variety of each area | region which comprises the opposing area | region 501 was equal to the width | variety of each separation member 123, the width | variety of each area | region which comprises the opposing area | region 501 is the width | variety of each separation member 123. It may be set more widely.

  In the above embodiment, the configuration in which the separation member 123 is arranged in contact with the heating roller 121 has been described as an example. However, in the present invention, the separation member 123 is arranged in contact with the pressure roller 122. Is also applicable.

  In the above-described embodiment, the case where the print control unit 220 temporarily stops the rotation of the heating roller 121 and the pressure roller 122 while stopping the conveyance operation of the paper P by the conveyance unit 40 has been described. The print control unit 220 may temporarily stop the rotation of the heating roller 121 and the pressure roller 122 without stopping the operation of the transport unit 40.

  In addition, in order to make it easy to understand, the drawings schematically show each component as a main component. Accordingly, the thickness, length, and the like of each illustrated component are different from actual ones for the convenience of drawing.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Image forming part 20 Control part 40 Conveying part 110 Image forming part 120 Fixing part 121 Heating roller 122 Pressure roller 123 Separating member 211 Calculation part 212 Determination part 213 Counting part 214 Determination part 215 Initialization part 216 Addition part

Claims (6)

An image forming apparatus for forming an image on a recording medium,
An image forming unit for forming a toner image on the recording medium;
A pair of rotatable rotating members that sandwich the recording medium and thermally fix the toner image on the recording medium;
A separation member disposed so as to contact one of the pair of rotation members and separating the recording medium from one of the pair of rotation members;
An image forming apparatus comprising: a controller that temporarily stops the rotation of the pair of rotating members at least once when images are continuously formed on the plurality of recording media.
A transport unit that transports the recording medium to the pair of rotating members via the image forming unit;
The image forming apparatus according to claim 1, wherein the control unit temporarily stops the rotation of the pair of rotation members while the conveyance unit stops the conveyance operation of the recording medium.
The controller is
A calculation unit that calculates an image density of an image formed in an area corresponding to the separation member on the recording medium based on image data;
A determination unit that determines a threshold according to the image density;
A counting unit that counts the number of recording media each time an image is formed;
A determination unit that determines whether the counting result of the counting unit matches the threshold every time the counting result of the counting unit changes;
An initialization unit that initializes the counting result of the counting unit each time the counting result of the counting unit matches the threshold value,
The image forming apparatus according to claim 1, wherein the rotation of the pair of rotating members is temporarily stopped every time the counting result of the counting unit matches the threshold value.
The image forming apparatus according to claim 3, wherein the determination unit determines a smaller threshold value as the image density increases.
The controller is
A calculation unit that calculates an image density of an image formed in an area corresponding to the separation member on the recording medium based on image data;
An addition unit that repeatedly adds the image density to obtain an addition value each time an image is formed;
An initialization unit that initializes the addition value each time the addition value becomes equal to or greater than the threshold value,
The image forming apparatus according to claim 1, wherein the rotation of the pair of rotating members is temporarily stopped every time the added value becomes equal to or greater than the threshold value.
The controller is
A calculation unit for calculating an image density of an image formed in an area corresponding to the separation member in each of the plurality of recording media based on a plurality of image data;
An adder that calculates an added value of the image density in the order in which the images are formed each time an image is formed;
A determination unit that determines whether or not the addition value is equal to or greater than a threshold each time the addition value changes;
An initialization unit that initializes the addition value each time the addition value becomes equal to or greater than the threshold value,
The image forming apparatus according to claim 1, wherein the rotation of the pair of rotating members is temporarily stopped every time the added value becomes equal to or greater than the threshold value.

Images