JP2024078808A - Image formation apparatus and acquisition method - Google Patents

Abstract

To provide an image formation apparatus capable of acquiring a content of a release agent in toner, and an acquisition method.SOLUTION: An image formation apparatus 100 includes: a fixation member which fixes a toner image transferred to a transfer object surface to the transfer object surface by coming into contact with the transfer object surface to which the toner image is transferred on a sheet; a transfer processing unit 62 which transfers a predefined specific toner image to the sheet that is conveyed via the fixation member; a detection processing unit 63 which detects an amount of a release agent adhering to a detection object region that is in contact with the specific toner image in the fixation member; and an acquisition processing unit 64 which acquires a content of the release agent in the toner used for formation of the toner image on the basis of a detection result by the detection processing unit 63.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electrophotographic image forming apparatus and an acquisition method.

Image forming devices that form images on sheets using an electrophotographic method are known (see, for example, Patent Document 1). The image forming device includes a fixing member that fixes the toner image transferred to the sheet to the sheet. The image forming device also forms an image using toner that contains a release agent to enhance releasability from the fixing member.

JP 2011-8120 A

However, if the release agent content in the toner is low, the leading edge of the sheet may stick to the fixing member together with the toner transferred to the leading edge of the sheet, causing a paper jam. In response to this, it is possible to extend the margin area at the leading edge of the sheet when the release agent content in the toner is equal to or less than a predetermined amount. However, the conventional image forming device does not have a function for acquiring the release agent content in the toner, and therefore is unable to acquire the release agent content in the toner.

The object of the present invention is to provide an image forming apparatus and method capable of acquiring the release agent content in a toner.

An image forming apparatus according to one aspect of the present invention includes a fixing member, a transfer processing unit, a detection processing unit, and an acquisition processing unit. The fixing member contacts a transfer surface of a sheet onto which a toner image has been transferred, and fixes the toner image transferred to the transfer surface. The transfer processing unit transfers a predetermined specific toner image to the sheet transported via the fixing member. The detection processing unit detects the amount of release agent adhering to a detection target area of the fixing member that has come into contact with the specific toner image. The acquisition processing unit acquires the amount of release agent contained in the toner used to form the toner image based on the detection result by the detection processing unit.

The determination method according to another aspect of the present invention is executed by an image forming apparatus equipped with a fixing member that comes into contact with a transfer surface onto which a toner image of a sheet has been transferred, and fixes the toner image transferred to the transfer surface to the transfer surface, and includes a transfer step, a detection step, and an acquisition step. In the transfer step, a predetermined specific toner image is transferred to the sheet transported via the fixing member. In the detection step, the amount of release agent adhering to a detection target area of the fixing member that has come into contact with the specific toner image is detected. In the acquisition step, the content of the release agent in the toner used to form the toner image is acquired based on the detection result from the detection step.

According to the present invention, it is possible to obtain the release agent content in the toner.

FIG. 1 is a cross-sectional view showing the configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing a system configuration of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing the configuration of an image forming unit of the image forming apparatus according to the embodiment of the present invention. FIG. 4 is a side view showing the configuration of the media sensor of the image forming apparatus according to the embodiment of the present invention. FIG. 5 is a diagram showing a detection toner image formed on a sheet by the image forming apparatus according to the embodiment of the present invention. FIG. 6 is a diagram showing a detection toner image formed on a sheet by the image forming apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart showing an example of a content acquisition process executed in the image forming apparatus according to the embodiment of the present invention.

The following describes an embodiment of the present invention with reference to the attached drawings. Note that the following embodiment is an example of the present invention and does not limit the technical scope of the present invention.

[Configuration of image forming apparatus 100]
First, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS.

For ease of explanation, the vertical direction in the installed state (as shown in FIG. 1) in which the image forming device 100 can be used is defined as the up-down direction D1. The left side of the paper surface of the image forming device 100 shown in FIG. 1 is defined as the front (front face) as the front direction D2. The left-right direction D3 is defined based on the front face of the image forming device 100 in the installed state.

The image forming device 100 is an image processing device having a print function that forms an image based on image data. Specifically, the image forming device 100 is a multifunction device having multiple functions including the print function. Note that the image forming device of the present invention may be a printer, fax machine, or copier having the print function.

As shown in FIG. 1 and FIG. 2, the image forming device 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a sheet conveying unit 4, an operation display unit 5, a memory unit 6, and a control unit 7.

The ADF 1 transports documents whose images are to be read by the image reading unit 2. The ADF 1 includes a document setting unit, multiple transport rollers, a document holder, and a paper discharge unit.

The image reading unit 2 provides a scanning function for reading an image of a document. The image reading unit 2 includes a document table, a light source, multiple mirrors, an optical lens, and a CCD (Charge Coupled Device).

The image forming unit 3 realizes the printing function. Specifically, the image forming unit 3 forms a color or monochrome image on a sheet supplied from the sheet conveying unit 4 according to an electrophotographic method. In other words, the image forming unit 3 forms an image on the sheet using toner.

The sheet conveying unit 4 conveys the sheet on which the image is formed by the image forming unit 3.

The operation display unit 5 is a user interface of the image forming device 100. The operation display unit 5 includes a display unit and an operation unit. The display unit displays various information in response to control instructions from the control unit 7. For example, the display unit is a liquid crystal display. The operation unit inputs various information to the control unit 7 in response to user operations. For example, the operation unit is a touch panel.

The storage unit 6 is a non-volatile storage device. For example, the storage unit 6 is a flash memory. The storage unit 6 may also be an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

The control unit 7 performs overall control of the image forming device 100. Note that the control unit 7 may be a control unit provided separately from the main control unit that performs overall control of the image forming device 100.

As shown in FIG. 2, the control unit 7 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 is a processor that executes various types of arithmetic processing. The ROM 12 is a non-volatile storage device in which information such as control programs for causing the CPU 11 to execute various types of processing is stored in advance. The RAM 13 is a volatile or non-volatile storage device used as a temporary storage memory (work area) for the various types of processing executed by the CPU 11. The CPU 11 comprehensively controls the image forming apparatus 100 by executing the various control programs stored in advance in the ROM 12. The control unit 7 may be configured with an electronic circuit such as an application specific integrated circuit (ASIC).

[Configuration of image forming unit 3]
Next, the configuration of the image forming section 3 will be described with reference to Figures 1 to 3. Here, Figure 3 is a cross-sectional view showing the configuration of the image forming unit 24.

As shown in FIG. 1, the image forming section 3 includes multiple image forming units 21 to 24, an optical scanning device 25, an intermediate transfer belt 26, a secondary transfer roller 27, a fixing device 28, and a paper output tray 29.

Image forming unit 21 forms a toner image on intermediate transfer belt 26 using the Y (yellow) toner. Image forming unit 22 forms a toner image on intermediate transfer belt 26 using the C (cyan) toner. Image forming unit 23 forms a toner image on intermediate transfer belt 26 using the M (magenta) toner. Image forming unit 24 forms a toner image on intermediate transfer belt 26 using the K (black) toner. As shown in FIG. 1, image forming units 21 to 24 are arranged side by side in the order of yellow, cyan, magenta, and black from the front side of image forming device 100 along the front-rear direction D2 of image forming device 100.

As shown in FIG. 3, image forming unit 24 includes a photoconductor drum 31, a charging roller 32, a developing device 33, a primary transfer roller 34, and a drum cleaning unit 35. Each of image forming units 21 to 23 has the same configuration as image forming unit 24. Each of image forming units 21 to 24 includes a toner container 36 shown in FIG. 1.

An electrostatic latent image is formed on the photosensitive drum 31. The photosensitive drum 31 receives a rotational driving force supplied from a motor (not shown) and rotates in the drum rotation direction D4 shown in FIG. 3. As a result, the photosensitive drum 31 transports the electrostatic latent image formed on its surface.

The charging roller 32 is applied with a preset charging voltage to charge the surface of the photoconductor drum 31. The surface of the photoconductor drum 31 charged by the charging roller 32 is irradiated with light based on image data emitted from the optical scanning device 25. This forms an electrostatic latent image on the surface of the photoconductor drum 31.

The developing device 33 develops the electrostatic latent image formed on the surface of the photosensitive drum 31. The developing device 33 includes a pair of stirring members and a developing roller. The pair of stirring members stir the toner and carrier contained inside the developing device 33. This stirring causes the toner and the carrier to be frictionally charged. The developing roller scoops up the toner stirred by the pair of stirring members and transports the toner to the opposing area between the developing roller and the photosensitive drum 31. In addition, the developing roller receives a preset development bias voltage and supplies the toner transported to the opposing area to the photosensitive drum 31. As a result, the toner is selectively supplied to the exposure area of the photosensitive drum 31 irradiated with light emitted from the optical scanning device 25, and the electrostatic latent image formed on the surface of the photosensitive drum 31 is developed. The toner is supplied to the developing device 33 from a toner container 36.

The primary transfer roller 34 receives a preset primary transfer current and transfers the toner image formed on the surface of the photoconductor drum 31 onto the intermediate transfer belt 26.

The drum cleaning unit 35 removes the toner remaining on the surface of the photoconductor drum 31 after the toner image is transferred by the primary transfer roller 34.

The optical scanning device 25 emits light based on image data toward the surface of the photoconductor drum 31 of each image forming unit 21 to 24.

The toner image formed on the surface of the photoconductor drum 31 of each of the image forming units 21 to 24 is transferred to the intermediate transfer belt 26. The intermediate transfer belt 26 is stretched at a predetermined tension by a drive roller, a tension roller, and four primary transfer rollers 34. The intermediate transfer belt 26 rotates in the belt rotation direction D5 shown in Figures 1 and 3 as the drive roller rotates in response to a rotational driving force supplied from a motor (not shown). As a result, the intermediate transfer belt 26 transports the transferred toner image.

The secondary transfer roller 27 receives a preset secondary transfer current and transfers the toner image transferred onto the surface of the intermediate transfer belt 26 onto a sheet transported by the sheet transport unit 4. The secondary transfer roller 27 is disposed opposite the drive roller, with the intermediate transfer belt 26 sandwiched between them. The secondary transfer roller 27 is biased toward the drive roller by a biasing member (not shown). This forms a transfer nip portion between the intermediate transfer belt 26 and the secondary transfer roller 27 that pinches the sheet.

The fixing device 28 fixes the toner image transferred to the sheet by the secondary transfer roller 27 to the sheet. As shown in FIG. 1, the fixing device 28 includes a fixing member 28A and a pressure member 28B. The fixing member 28A comes into contact with the transfer surface of the sheet to which the toner image has been transferred, and fixes the toner image transferred to the transfer surface to the transfer surface. Specifically, the fixing member 28A is a roller- or belt-shaped member that heats the toner image transferred to the sheet. The temperature of the fixing member 28A is maintained at a predetermined fixing control temperature by a heater (not shown). The pressure member 28B is a roller-shaped member that presses the sheet. The pressure member 28B is urged toward the fixing member 28A by an urging member (not shown). As a result, a fixing nip portion that pinches the sheet is formed between the fixing member 28A and the pressure member 28B.

Here, the toner contains a release agent to improve releasability from the fixing member 28A. For example, the release agent is a natural ester wax such as carnauba wax, or a synthetic ester wax.

The sheet on which the toner image has been fixed by the fixing device 28 is discharged onto the discharge tray 29.

[Configuration of Sheet Conveying Unit 4]
Next, the configuration of the sheet conveying unit 4 will be described with reference to Fig. 1, Fig. 2, and Fig. 4. Fig. 4 shows the configuration of the media sensor 48 and the pre-reversal sheet SH1 before passing through the reversal conveying path 47.

As shown in FIG. 1, the sheet transport unit 4 includes a paper feed cassette 41, a pickup roller 42, a paper feed roller 43, a separation roller 44, a paper feed path 45, a paper discharge path 46, a reverse transport path 47, and a media sensor 48.

The paper feed cassette 41 contains sheets on which an image is formed by the image forming unit 3. For example, the paper feed cassette 41 contains sheets such as paper, coated paper, postcards, envelopes, and overhead projector sheets. A lift plate 41A (see FIG. 1) is provided at the bottom of the paper feed cassette 41. The lift plate 41A lifts the stack of sheets contained in the paper feed cassette 41 to a contact position with the pickup roller 42.

The pickup roller 42 is provided above the paper feed cassette 41. The pickup roller 42 comes into contact with the top sheet in the sheet stack lifted by the lift plate 41A and transports the sheet to the paper feed roller 43.

The paper feed roller 43 is provided in the paper feed path 45 and contacts the upper surface of the sheet transported by the pickup roller 42 to transport the sheet in the first transport direction D6 (see FIG. 1).

The separation roller 44 is provided below the paper feed roller 43. The separation roller 44 is biased toward the paper feed roller 43 by a biasing member (not shown). This forms a paper feed nip portion between the paper feed roller 43 and the separation roller 44 that pinches the sheet. When multiple sheets are transported to the nip portion, the separation roller 44 separates the sheet that comes into contact with the paper feed roller 43 from the other sheets.

The paper feed path 45 is a path along which the sheet travels from the paper feed cassette 41 to the transfer nip where the toner image is transferred by the secondary transfer roller 27. In the paper feed path 45, the sheet is transported in the first transport direction D6 shown in Figures 1 and 4.

The discharge path 46 is a passageway along which the sheet travels from the transfer nip portion through the fixing nip portion to the discharge tray 29. In the discharge path 46, the sheet is transported in the second transport direction D7 shown in FIG. 1. A discharge roller 46A (see FIG. 1) is provided at the downstream end of the discharge path 46 in the second transport direction D7. The discharge roller 46A discharges the sheet to the discharge tray 29.

The reversing conveying path 47 is used to reverse the sheet that has passed through the secondary transfer roller 27 and the pressure member 28B, and to re-convey the sheet to the secondary transfer roller 27 and the pressure member 28B. The reversing conveying path 47 branches off from the paper discharge path 46 at a branching position P1 (see FIG. 1) downstream of the pressure member 28B in the paper discharge path 46 in the second conveying direction D7. The reversing conveying path 47 also merges with the paper feed path 45 at a merging position P2 (see FIG. 1) upstream of the secondary transfer roller 27 in the first conveying direction D6 in the paper feed path 45. In the reversing conveying path 47, the sheet is conveyed in the third conveying direction D8 shown in FIG. 1.

As shown in FIG. 1, a movable guide member 46B is provided at branch position P1 in discharge path 46. The movable guide member 46B is provided so as to be capable of changing its position between a first position (see FIG. 1) in which the sheet conveyed in the second conveying direction D7 is guided to discharge rollers 46A, and a second position in which the sheet conveyed by discharge rollers 46A in the direction opposite to the second conveying direction D7 is guided to reverse conveying path 47.

In the image forming device 100, when images are formed on both sides of a sheet, the discharge roller 46A and the movable guide member 46B are used to send the sheet with an image formed on one side to the reverse transport path 47. Specifically, the control unit 7 reverses the rotation of the discharge roller 46A after the rear end of the sheet transported in the second transport direction D7 passes through the branch position P1 and before the sheet is discharged to the discharge tray 29. This causes the sheet to be transported in the opposite direction to the second transport direction D7. The control unit 7 also changes the position of the movable guide member 46B from the first position to the second position. This causes the sheet transported in the opposite direction to the second transport direction D7 to be guided to the reverse transport path 47.

The media sensor 48 is used to determine the type of sheet. As shown in FIG. 1, the media sensor 48 is located upstream of the secondary transfer roller 27 in the paper feed path 45 in the first transport direction D6 and downstream of the joining position P2 with the reverse transport path 47 in the first transport direction D6.

The media sensor 48 includes an optical sensor 51 and a thickness sensor 52 as shown in FIG. 2.

The optical sensor 51 includes a light emitting portion 51A shown in FIG. 4.

The light emitting unit 51A emits emission light L1 (see FIG. 4) toward the surface of the pre-inversion sheet SH1 (see FIG. 4) opposite to the surface onto which the toner image is transferred before passing through the inversion transport path 47, upstream of the secondary transfer roller 27 in the paper feed path 45 in the first transport direction D6 and downstream of the joining position P2 with the inversion transport path 47. The light emitting unit 51A also emits emission light L1 toward the transferred surface of the post-inversion sheet after passing through the fixing member 28A and passing through the inversion transport path 47. In FIG. 4, the emission light L1 is indicated by a thick line with an arrow.

For example, the light emitting unit 51A is a light emitting element such as a light emitting diode that emits light of a predetermined wavelength. The light emitting unit 51A may also include a light guiding member that guides the light emitted from the light emitting element.

The optical sensor 51 detects the amount of reflected light L2 (see FIG. 4), which is the regular reflected light reflected by the pre-inversion sheet SH1 or the post-inversion sheet, out of the emitted light L1 emitted from the light emitting section 51A. In FIG. 4, the reflected light L2 is indicated by a solid line with an arrow.

Specifically, the optical sensor 51 includes a light receiving unit 51B shown in FIG. 4.

For example, the light receiving unit 51B is a light receiving element such as a phototransistor that outputs a first electrical signal having a signal value corresponding to the amount of reflected light L2 in response to receiving the reflected light L2. The first electrical signal output from the light receiving unit 51B is input to the control unit 7.

The thickness sensor 52 detects the thickness of the pre-inversion sheet SH1 upstream of the secondary transfer roller 27 in the paper feed path 45 in the first transport direction D6 and downstream of the merging position P2 in the first transport direction D6.

The thickness sensor 52 includes a lever member 52A shown in FIG. 4. The thickness sensor 52 also includes a displacement detection unit (not shown).

The lever member 52A is provided so that it can be displaced from a predetermined reference position by contact with the pre-reversal sheet SH1. In FIG. 4, the lever member 52A installed at the reference position is indicated by a dashed line. For example, the lever member 52A is provided so that it can be pivoted about the pivot shaft 52B shown in FIG. 4. The pivot shaft 52B is an axis that extends in the width direction (left-right direction D3) of the pre-reversal sheet SH1, which is perpendicular to the first conveying direction D6 (see FIG. 4). The lever member 52A is displaced from the reference position in the pivot direction about the pivot shaft 52B by an amount according to the thickness of the pre-reversal sheet SH1 by contact with the pre-reversal sheet SH1.

The displacement amount detection unit detects the amount of displacement of the lever member 52A from the reference position. For example, the displacement amount detection unit is an electric circuit that includes a variable resistor whose electrical resistance changes in response to the rotation of the pivot shaft 52B and outputs a second electric signal whose signal value corresponds to the electrical resistance of the variable resistor. The second electric signal output from the displacement amount detection unit is input to the control unit 7.

However, if the release agent content in the toner is low, the leading edge of the sheet may stick to the fixing member 28A together with the toner transferred to the leading edge of the sheet, causing a paper jam. In response to this, it is possible to extend the margin area at the leading edge of the sheet when the release agent content in the toner is below a predetermined amount. However, conventional image forming devices are not equipped with a function for acquiring the release agent content in the toner, and therefore are unable to acquire the release agent content in the toner.

In contrast, in the image forming apparatus 100 according to an embodiment of the present invention, the release agent content in the toner can be obtained as described below.

[Configuration of control unit 7]
Next, the configuration of the control unit 7 will be described with reference to FIG.

As shown in FIG. 2, the control unit 7 includes a cleaning processing unit 61, a transfer processing unit 62, a detection processing unit 63, an acquisition processing unit 64, an extension processing unit 65, a notification processing unit 66, and an adjustment processing unit 67.

Specifically, an operation control program for causing the CPU 11 of the control unit 7 to function as each of the above-mentioned units is stored in advance in the ROM 12 of the control unit 7. The CPU 11 of the control unit 7 then executes the operation control program stored in the ROM 12 to function as each of the above-mentioned functional units. Note that some or all of the functional units included in the control unit 7 may be configured with electronic circuits. The operation control program may also be a program for causing multiple processors to function as each of the functional units included in the control unit 7.

The cleaning processing unit 61 cleans the contact surface of the fixing member 28A that comes into contact with the sheet.

For example, the cleaning unit 61 cleans the contact surface by transporting a sheet, the surface of which that comes into contact with the contact surface not having toner transferred thereto, via the fixing member 28A. In other words, the cleaning unit 61 transfers dirt from the contact surface to the sheet transported via the fixing member 28A. The image forming apparatus 100 may also include a cleaning member that is movable between a first position where the cleaning unit comes into contact with the contact surface and cleans the contact surface, and a second position where the cleaning unit is spaced apart from the contact surface. In this case, the cleaning unit 61 may clean the contact surface using the cleaning member.

For example, the cleaning processing unit 61 transports a blank sheet from the paper feed cassette 41 to the paper discharge tray 29 without passing through the reversing transport path 47. The cleaning processing unit 61 may also transport a blank sheet from the paper feed cassette 41 to the paper discharge tray 29 via the reversing transport path 47. The cleaning processing unit 61 may also transport the inverted sheet, which has a toner image transferred to only one side, via the fixing member 28A.

The transfer processing unit 62 transfers a predetermined detection toner image T10 (see FIG. 5) onto the sheet transported via the fixing member 28A. The detection toner image T10 is an example of a specific toner image of the present invention.

For example, when the contact surface is cleaned by the cleaning processing unit 61, the transfer processing unit 62 transfers the detection toner image T10 to the sheet transported via the fixing member 28A. Note that the transfer processing unit 62 may transfer the detection toner image T10 to the sheet transported via the fixing member 28A at a timing different from the timing when the contact surface is cleaned by the cleaning processing unit 61.

For example, the transfer processing unit 62 transfers four detection toner images T11 to T14 (see FIG. 5) corresponding to the four image forming units 21 to 24 (see FIG. 1) onto a sheet transported via the fixing member 28A. Specifically, the detection toner image T11 is a Y (yellow) toner image having a predetermined density. The detection toner image T12 is a C (cyan) toner image having a predetermined density. The detection toner image T13 is an M (magenta) toner image having a predetermined density. The detection toner image T14 is a K (black) toner image having a predetermined density. The transfer processing unit 62 may transfer only one of the four detection toner images T11 to T14 onto a sheet transported via the fixing member 28A.

Now, the detection toner image T10 will be described with reference to FIG. 5. FIG. 5 shows the pre-inversion sheet SH1 onto which the detection toner images T11 to T14 have been transferred, being transported along the paper discharge path 46 (see FIG. 1). Note that in FIG. 5, each of the four detection toner images T11 to T14 is hatched.

The detection toner image T10 is a toner image whose size in the second transport direction D7 is equal to or smaller than the circumference X1 (see FIG. 5) of the fixing member 28A. For example, as shown in FIG. 5, each detection toner image T10 is a toner image whose size in the second transport direction D7 is shorter than the divided circumference X2 (see FIG. 5) obtained by dividing the circumference X1 into four equal parts. Each detection toner image T10 may be a toner image whose size in the second transport direction D7 is the same as the divided circumference X2. In addition, when the number of detection toner images T10 transferred to the sheet by the transfer processing unit 62 is one, the size in the second transport direction D7 of that one detection toner image T10 may be the same as the circumference X1.

For example, as shown in FIG. 5, each detection toner image T10 is a rectangular toner image. Note that each detection toner image T10 may be a toner image having a shape other than rectangular.

As shown in FIG. 5, the four detection toner images T11-T14 are transferred upstream of the downstream end of the pre-inversion sheet SH1 in the second transport direction D7. The four detection toner images T11-T14 are transferred side by side along the second transport direction D7. The four detection toner images T11-T14 are transferred so that the row distance along the second transport direction D7 formed by the four detection toner images T11-T14 is equal to or less than the circumference X1. Hereinafter, the area between the downstream end of the pre-inversion sheet SH1 in the second transport direction D7 and the detection toner image T11 located furthest downstream in the second transport direction D7 among the four detection toner images T11-T14 is referred to as the reference area R11 (see FIG. 5).

In the image forming apparatus 100, the pre-reversal sheet SH1 onto which the four detection toner images T11 to T14 have been transferred by the transfer processing unit 62 passes through the fixing nip. As a result, the four detection toner images T11 to T14 transferred onto the pre-reversal sheet SH1 are fixed onto the pre-reversal sheet SH1. In addition, the release agent adheres to each of the four detection target areas that come into contact with the four detection toner images T11 to T14 on the contact surface of the fixing member 28A.

The detection processing unit 63 detects the amount of release agent adhering to the detection target area that comes into contact with the detection toner image T10 on the fixing member 28A.

For example, the detection processing unit 63 detects the amount of the release agent adhering to the sheet due to contact between the detection target area and the sheet as the amount of the release agent adhering to the detection target area. Note that the detection processing unit 63 may directly detect the amount of the release agent adhering to the detection target area using a sensor capable of detecting the amount of the release agent adhering to the detection target area.

For example, the detection processing unit 63 uses the optical sensor 51 of the media sensor 48 (see FIG. 1) to detect the amount of the release agent that adheres to the sheet due to contact between the detection target area and the sheet.

Specifically, in the image forming apparatus 100, the reversing conveying path 47 is used to reverse the pre-reversal sheet SH1 on which the four detection toner images T11 to T14 are fixed. Then, the reversing sheet SH2 (see FIG. 6) on which the four detection toner images T11 to T14 are fixed on one side is conveyed via the media sensor 48.

Figure 6 shows the surface of the inverted sheet SH2, on which the detection toner images T11 to T14 are fixed, that faces the optical sensor 51 and is transported along the paper feed path 45.

The detection processing unit 63 causes the light emitting unit 51A to emit the emission light L1 at the timing when the fourth region R24 (see FIG. 6) of the inverted sheet SH2 (see FIG. 6) passes through the irradiation position of the emission light L1. The detection processing unit 63 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the fourth region R24, which is output from the light receiving unit 51B in response to the emission of the emission light L1 by the light emitting unit 51A. Here, the fourth region R24 is the region of the pre-inversion sheet SH1 (see FIG. 5) that first comes into contact with the detection target region corresponding to the detection toner image T14. In other words, in the pre-inversion sheet SH1, the fourth region R24 is a region separated from the detection toner image T14 by the circumference X1 upstream in the second transport direction D7.

The detection processing unit 63 also causes the light emitting unit 51A to emit the emission light L1 at the timing when the third region R23 (see FIG. 6) in the inverted sheet SH2 (see FIG. 6) passes through the irradiation position of the emission light L1. The detection processing unit 63 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the third region R23, which is output from the light receiving unit 51B in response to the emission of the emission light L1 by the light emitting unit 51A. Here, the third region R23 is the region in the pre-inversion sheet SH1 (see FIG. 5) that first comes into contact with the detection target region corresponding to the detection toner image T13. In other words, in the pre-inversion sheet SH1, the third region R23 is a region separated from the detection toner image T13 by the circumference X1 upstream in the second transport direction D7.

The detection processing unit 63 also causes the light emitting unit 51A to emit the emission light L1 at the timing when the second region R22 (see FIG. 6) in the inverted sheet SH2 (see FIG. 6) passes through the irradiation position of the emission light L1. The detection processing unit 63 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the second region R22, which is output from the light receiving unit 51B in response to the emission of the emission light L1 by the light emitting unit 51A. Here, the second region R22 is the region in the pre-inversion sheet SH1 (see FIG. 5) that first comes into contact with the detection target region corresponding to the detection toner image T12. In other words, in the pre-inversion sheet SH1, the second region R22 is a region separated from the detection toner image T12 by the circumference X1 upstream in the second transport direction D7.

The detection processing unit 63 also causes the light emitting unit 51A to emit the emission light L1 at the timing when the first region R21 (see FIG. 6) in the inverted sheet SH2 (see FIG. 6) passes through the irradiation position of the emission light L1. The detection processing unit 63 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the first region R21, which is output from the light receiving unit 51B in response to the emission of the emission light L1 by the light emitting unit 51A. Here, the first region R21 is the region in the pre-inversion sheet SH1 (see FIG. 5) that first comes into contact with the detection target region corresponding to the detection toner image T11. In other words, in the pre-inversion sheet SH1, the first region R21 is a region separated from the detection toner image T11 by the circumference X1 upstream in the second transport direction D7.

The detection processing unit 63 also causes the light emitting unit 51A to emit the emission light L1 at the timing when the reference region R11 (see FIG. 6) on the inverted sheet SH2 (see FIG. 6) passes through the irradiation position of the emission light L1. The detection processing unit 63 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the reference region R11, which is output from the light receiving unit 51B in response to the emission of the emission light L1 by the light emitting unit 51A.

Then, the detection processing unit 63 acquires the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the first region R21 (hereinafter referred to as the "first detection value") as a value indicating the amount of the release agent adhered to the first region R21. In other words, the detection processing unit 63 acquires the first detection value as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T11.

The detection processing unit 63 also acquires the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the second region R22 (hereinafter referred to as the "second detection value") as a value indicating the amount of the release agent adhered to the second region R22. In other words, the detection processing unit 63 acquires the second detection value as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T12.

The detection processing unit 63 also acquires the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the third region R23 (hereinafter referred to as the "third detection value") as a value indicating the amount of the release agent adhered to the third region R23. In other words, the detection processing unit 63 acquires the third detection value as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T13.

The detection processing unit 63 also acquires the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the fourth region R24 (hereinafter referred to as the "fourth detection value") as a value indicating the amount of the release agent adhered to the fourth region R24. In other words, the detection processing unit 63 acquires the fourth detection value as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T14.

Hereinafter, the first detection value, the second detection value, the third detection value, and the fourth detection value may be collectively referred to as "detection values."

In addition, in the image forming apparatus 100, another optical sensor having a configuration similar to that of the optical sensor 51 may be provided downstream of the fixing member 28A in the second transport direction D7 in the paper discharge path 46 (see FIG. 1). In this case, the detection processing unit 63 may use the other optical sensor to detect the amount of the release agent adhering to the sheet due to contact between the detection target area and the sheet. In addition, the detection processing unit 63 may detect the amount of the release agent using a type of sensor different from the optical sensor 51 that is capable of detecting the amount of the release agent adhering to the sheet.

The acquisition processing unit 64 acquires the release agent content in the toner based on the detection results by the detection processing unit 63.

Specifically, the acquisition processing unit 64 acquires the release agent content in the Y (yellow) toner based on the first detection value acquired by the detection processing unit 63.

The acquisition processing unit 64 also acquires the release agent content in the C (cyan) toner based on the second detection value acquired by the detection processing unit 63.

The acquisition processing unit 64 also acquires the release agent content in the M (magenta) toner based on the third detection value acquired by the detection processing unit 63.

The acquisition processing unit 64 also acquires the release agent content in the K (black) toner based on the fourth detection value acquired by the detection processing unit 63.

For example, the acquisition processing unit 64 acquires the release agent content in the toner using table data that indicates the correspondence between the detection value and the release agent content in the toner, which is provided for each fixing control temperature.

Here, the table data can be created based on data obtained for each of a plurality of toners having different release agent contents, in which the release agent contents in the toners correspond to the detection values obtained using the toners. The table data created for each fixing control temperature may be stored in advance in the storage unit 6.

The acquisition processing unit 64 may acquire the release agent content in the toner using a relational equation that indicates the relationship between the detection value and the release agent content in the toner, the relational equation being set for each fixing control temperature.

The extension processing unit 65 extends the margin area at the leading edge of the sheet when the release agent content acquired by the acquisition processing unit 64 is equal to or less than a predetermined first threshold value (an example of the threshold value of the present invention).

For example, the extension processing unit 65 extends the margin area at the leading edge of the sheet when the release agent content of at least one color of toner is equal to or less than the first threshold value. Note that the extension processing unit 65 may extend the margin area at the leading edge of the sheet when the release agent content of multiple colors of toner is equal to or less than the first threshold value.

For example, the extension processing unit 65 extends the margin area at the leading edge of the sheet by accelerating the timing of conveying the sheet to the transfer nip. The extension processing unit 65 may also extend the margin area at the leading edge of the sheet by changing the layout of the image to be printed on the sheet.

The first threshold value may be set based on the results of an experiment in which the release agent content in the toner is increased or decreased in stages and the occurrence of paper jams is confirmed at each stage.

The notification processing unit 66 notifies the user when the release agent content acquired by the acquisition processing unit 64 is outside a predetermined specific range.

For example, the notification processing unit 66 causes the operation display unit 5 to display a message for each of the toners whose release agent content is outside the specific range, indicating that the toner is not a predetermined specific type of toner. For example, the specific type of toner is a toner manufactured by a predetermined manufacturer. The control unit 7 may also cause a display unit of an external information processing device communicatively connected to the image forming apparatus 100 to display a message for each of the toners whose release agent content is outside the specific range, indicating that the toner is not a predetermined specific type of toner.

The specific range may be set based on the variation in the release agent content in the specific type of toner.

The adjustment processing unit 67 adjusts the temperature of the fixing member 28A based on the release agent content acquired by the acquisition processing unit 64.

For example, the adjustment processing unit 67 reduces the fixing control temperature by a predetermined value when the release agent content of at least one color of toner exceeds a second threshold value that is higher than the first threshold value. The adjustment processing unit 67 may also reduce the fixing control temperature when the release agent content of multiple colors of toner exceeds the second threshold value.

In addition, the adjustment processing unit 67 may increase the fixing control temperature by a predetermined value when the content of the release agent for at least one color or multiple colors of the toner is equal to or less than the first threshold value. In this case, the extension processing unit 65 does not need to extend the margin area at the leading edge of the sheet.

[Content Acquisition Process]
7, an example of a content acquisition process executed by the control unit 7 in the image forming apparatus 100 and an acquisition method of the present invention will be described. Here, steps S11, S12, ... represent the numbers of the processing procedures (steps) executed by the control unit 7. For example, the content acquisition process is executed when the image forming apparatus 100 is powered on. The content acquisition process may be executed in response to a user's operation on the operation display unit 5. The content acquisition process may also be executed when it is determined that any of the toner containers 36 has been replaced.

<Step S11>
First, in step S11, the control unit 7 cleans the contact surface of the fixing member 28A. The process of step S11 is executed by the cleaning process unit 61 of the control unit 7.

Specifically, the control unit 7 transports a blank sheet from the paper feed cassette 41 to the paper discharge tray 29 without passing through the reversing transport path 47.

<Step S12>
In step S<b>12 , the control unit 7 conveys the sheet from the sheet feed cassette 41 to the sheet discharge tray 29 via the reversing conveying path 47 .

<Step S13>
In step S13, the control unit 7 transfers the detection toner image T10 (see FIG. 5) onto the pre-reversal sheet SH1 conveyed by the process of step S12. Here, the process of step S13 is executed by the transfer processing unit 62 of the control unit 7. The process of step S13 is an example of a transfer step of the present invention.

Specifically, the control unit 7 controls the operation of the image forming units 21 to 24, the optical scanning device 25, the intermediate transfer belt 26, and the secondary transfer roller 27 to transfer the four detection toner images T11 to T14 (see Figure 5) onto the pre-inversion sheet SH1.

<Step S14>
In step S14, the control unit 7 detects the amount of the release agent adhering to the detection target area that has come into contact with the detection toner image T10 transferred to the pre-reversal sheet SH1 by the process of step S13 in the fixing member 28A. Here, the process of step S14 is executed by the detection processing unit 63 of the control unit 7. The process of step S14 is an example of a detection step of the present invention.

Specifically, the control unit 7 causes the light emitting unit 51A to emit the emitted light L1 at the timing when the fourth region R24 of the inverted sheet SH2 (see FIG. 6) on which the four detection toner images T11 to T14 are fixed passes through the irradiation position of the emitted light L1. The control unit 7 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the fourth region R24, which is output from the light receiving unit 51B in response to the emission of the emitted light L1 by the light emitting unit 51A.

The control unit 7 also causes the light emitting unit 51A to emit the emitted light L1 at the timing when the third region R23 of the inverted sheet SH2 (see FIG. 6) on which the four detection toner images T11 to T14 are fixed passes through the irradiation position of the emitted light L1. The control unit 7 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the third region R23, which is output from the light receiving unit 51B in response to the emission of the emitted light L1 by the light emitting unit 51A.

The control unit 7 also causes the light emitting unit 51A to emit the emitted light L1 at the timing when the second region R22 of the inverted sheet SH2 (see FIG. 6) on which the four detection toner images T11 to T14 are fixed passes through the irradiation position of the emitted light L1. The control unit 7 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the second region R22, which is output from the light receiving unit 51B in response to the emission of the emitted light L1 by the light emitting unit 51A.

The control unit 7 also causes the light emitting unit 51A to emit the emitted light L1 at the timing when the first region R21 of the inverted sheet SH2 (see FIG. 6) on which the four detection toner images T11 to T14 are fixed passes through the irradiation position of the emitted light L1. The control unit 7 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected by the first region R21, which is output from the light receiving unit 51B in response to the emission of the emitted light L1 by the light emitting unit 51A.

The control unit 7 also causes the light emitting unit 51A to emit the emitted light L1 at the timing when the reference region R11 in the inverted sheet SH2 (see FIG. 6) on which the four detection toner images T11 to T14 are fixed passes through the irradiation position of the emitted light L1. The control unit 7 also acquires the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the reference region R11, which is output from the light receiving unit 51B in response to the emission of the emitted light L1 by the light emitting unit 51A.

Then, the control unit 7 acquires the first detection value, which is the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the first region R21, as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T11.

The control unit 7 also acquires the second detection value, which is the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the second region R22, as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T12.

The control unit 7 also acquires the third detection value, which is the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the third region R23, as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T13.

The control unit 7 also acquires the fourth detection value, which is the difference between the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the reference region R11 and the signal value of the first electrical signal corresponding to the reflected light L2 reflected at the fourth region R24, as a value indicating the amount of the release agent adhered to the detection target region corresponding to the detection toner image T14.

<Step S15>
In step S15, the control unit 7 acquires the content of the release agent in the toner based on the detection result in the process of step S14. Here, the process of step S15 is executed by the acquisition processing unit 64 of the control unit 7. The process of step S15 is an example of the acquisition step of the present invention.

Specifically, the acquisition processing unit 64 acquires the release agent content in the toner for each toner color using the table data corresponding to the current fixing control temperature.

<Step S16>
In step S16, the control unit 7 determines whether or not the amount of the release agent obtained in the process of step S15 is outside the specific range.

Specifically, when at least one of the contents of the multiple release agents corresponding to the multiple colors obtained by the processing of step S15 is outside the specific range, the control unit 7 determines that the obtained content of the release agent is outside the specific range.

Here, if the control unit 7 determines that the content of the release agent obtained is outside the specific range (Yes side of S16), it shifts the process to step S17. If the control unit 7 determines that the content of the release agent obtained is not outside the specific range (No side of S16), it shifts the process to step S18.

<Step S17>
In step S17, the control unit 7 executes a notification process to notify the user that the content of the release agent obtained in the process of step S15 is outside the specific range. Here, the process of step S17 is executed by the notification processing unit 66 of the control unit 7.

Specifically, for each toner determined to have a release agent content outside the specific range, the control unit 7 causes the operation display unit 5 to display a message indicating that the toner is not the specific type of toner. This allows the user of the image forming device 100 to recognize that the toner being used is not the specific type of toner.

<Step S18>
In step S18, the control unit 7 determines whether or not the amount of the release agent obtained in the process of step S15 is equal to or less than the first threshold value.

Specifically, when at least one of the contents of the multiple release agents corresponding to the multiple colors obtained by the processing of step S15 is equal to or less than the first threshold value, the control unit 7 determines that the obtained content of the release agent is equal to or less than the first threshold value.

Here, when the control unit 7 determines that the content of the release agent obtained is equal to or less than the first threshold value (Yes side of S18), it shifts the process to step S19. When the control unit 7 determines that the content of the release agent obtained is not equal to or less than the first threshold value (No side of S18), it shifts the process to step S20.

<Step S19>
In step S19, the control unit 7 executes an extension process to extend the margin area at the leading edge of the sheet. The process in step S19 is executed by the extension processing unit 65 of the control unit 7.

Specifically, the control unit 7 advances the timing of conveying the sheet to the transfer nip, thereby expanding the margin area at the leading edge of the sheet. This makes it possible to prevent the leading edge of the sheet from sticking to the fixing member 28A together with the toner transferred to the leading edge of the sheet, thereby preventing paper jams.

<Step S20>
In step S20, the control unit 7 determines whether or not the amount of the release agent obtained in the process of step S15 exceeds the second threshold value.

Specifically, the control unit 7 determines that the content of the release agent obtained exceeds the second threshold value when at least one of the contents of the release agents corresponding to the multiple colors obtained by the processing of step S15 exceeds the second threshold value.

Here, when the control unit 7 determines that the acquired amount of the release agent exceeds the second threshold (Yes side of S20), it shifts the process to step S21. When the control unit 7 determines that the acquired amount of the release agent does not exceed the second threshold (No side of S20), it ends the amount acquisition process.

<Step S21>
In step S21, the control unit 7 adjusts the temperature of the fixing member 28 A. The process of step S21 is executed by the adjustment processing unit 67 of the control unit 7.

Specifically, the control unit 7 lowers the fixing control temperature by a predetermined value. This makes it possible to reduce power consumption in the fixing device 28 without increasing the probability of paper jams.

In this way, the image forming apparatus 100 includes a transfer processing unit 62 that transfers the detection toner image T10 onto the sheet transported via the fixing member 28A, a detection processing unit 63 that detects the amount of release agent adhering to the detection target area that has come into contact with the detection toner image T10 on the fixing member 28A, and an acquisition processing unit 64 that acquires the release agent content in the toner based on the detection result by the detection processing unit 63. This makes it possible to acquire the release agent content in the toner.

In addition, in the image forming device 100, the amount of release agent adhering to the sheet is detected using an optical sensor 51 included in the media sensor 48 used to determine the type of sheet. This makes it possible to reduce the number of sensors compared to a configuration that includes the other optical sensor in addition to the optical sensor 51.

[Notes on the invention]
The following will provide an overview of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

<Appendix 1>
an image forming apparatus comprising: a fixing member that comes into contact with a transfer surface onto which a toner image of a sheet has been transferred, and fixes the toner image transferred to the transfer surface; a transfer processing unit that transfers a predetermined specific toner image onto the sheet transported via the fixing member; a detection processing unit that detects an amount of release agent adhering to a detection target area of the fixing member that has come into contact with the specific toner image; and an acquisition processing unit that acquires the content of the release agent in the toner used to form the toner image based on the detection result by the detection processing unit.

<Appendix 2>
2. The image forming apparatus according to claim 1, wherein the detection processing unit detects the amount of release agent adhering to the sheet due to contact between the detection target area and the sheet as the amount of release agent adhering to the detection target area.

<Appendix 3>
An image forming apparatus as described in Appendix 2, including a light emitting unit that emits emission light toward the transferred surface of the sheet that has passed through the fixing member, and a photosensor that detects the amount of reflected light reflected by the sheet from the emission light emitted from the light emitting unit, wherein the detection processing unit uses the photosensor to detect the amount of release agent adhered to the sheet due to contact between the detection target area and the sheet.

<Appendix 4>
An image forming apparatus as described in Appendix 3, further comprising a cleaning processing unit that cleans a contact surface of the fixing member that comes into contact with the sheet, and the transfer processing unit transfers the specific toner image to the sheet transported via the fixing member when the contact surface has been cleaned by the cleaning processing unit.

<Appendix 5>
The image forming apparatus according to claim 4, wherein the cleaning processing section cleans the contact surface by transporting the sheet, which does not have toner transferred to its surface that comes into contact with the contact surface, through the fixing member.

<Appendix 6>
6. The image forming apparatus according to claim 1, further comprising an extension processing unit that extends a margin area at a leading end of the sheet when the content of the release agent acquired by the acquisition processing unit is equal to or less than a predetermined threshold value.

<Appendix 7>
7. The image forming apparatus according to claim 1, further comprising a notification processing unit that notifies a user when the content of the release agent acquired by the acquisition processing unit is outside a predetermined specific range.

<Appendix 8>
8. The image forming apparatus according to claim 1, further comprising an adjustment processing unit that adjusts a temperature of the fixing member based on the content of the release agent acquired by the acquisition processing unit.

<Appendix 9>
An acquisition method performed in an image forming apparatus equipped with a fixing member that comes into contact with a transfer surface onto which a toner image on a sheet has been transferred, and fixes the toner image transferred to the transfer surface onto the transfer surface, the acquisition method including: a transfer step that transfers a predetermined specific toner image onto the sheet transported via the fixing member; a detection step that detects the amount of release agent adhering to a detection target area on the fixing member that has come into contact with the specific toner image; and an acquisition step that acquires the content of the release agent in the toner used to form the toner image based on the detection result by the detection step.

1 ADF
2 Image reading section 3 Image forming section 4 Sheet conveying section 5 Operation display section 6 Storage section 7 Control section 21 Image forming unit (Y)
22 Image forming unit (C)
23 Image forming unit (M)
24 Image forming unit (K)
Reference Signs List 25 Optical scanning device 26 Intermediate transfer belt 27 Secondary transfer roller 28 Fixing device 28A Fixing member 45 Paper feed path 46 Paper discharge path 47 Reversal transport path 48 Media sensor 51 Optical sensor 61 Cleaning processing unit 62 Transfer processing unit 63 Detection processing unit 64 Acquisition processing unit 65 Decompression processing unit 66 Notification processing unit 67 Adjustment processing unit 100 Image forming apparatus

Claims (9)

a fixing member that comes into contact with a receiving surface of the sheet onto which the toner image has been transferred, and fixes the toner image transferred onto the receiving surface;
a transfer processing unit that transfers a predetermined specific toner image onto the sheet conveyed via the fixing member;
a detection processing unit that detects an amount of release agent adhering to a detection target area of the fixing member that has come into contact with the specific toner image;
an acquisition processing unit that acquires a content of the release agent in the toner used to form the toner image based on a detection result by the detection processing unit;
An image forming apparatus comprising: the detection processing unit detects an amount of the release agent adhering to the sheet due to contact between the detection target area and the sheet as the amount of the release agent adhering to the detection target area.
The image forming apparatus according to claim 1 . a light emitting section that emits light toward the transferred surface of the sheet that has passed through the fixing member, and a light sensor that detects an amount of reflected light reflected by the sheet out of the light emitted from the light emitting section,
the detection processing unit detects, by using the optical sensor, the amount of the release agent adhering to the sheet due to contact between the detection target area and the sheet;
The image forming apparatus according to claim 2 . a cleaning processing section configured to clean a contact surface of the fixing member that comes into contact with the sheet,
the transfer processing unit transfers the specific toner image onto the sheet transported via the fixing member when the contact surface is cleaned by the cleaning processing unit.
The image forming apparatus according to claim 3 . the cleaning processing section cleans the contact surface by conveying the sheet, the surface of which contacts the contact surface and toner is not transferred, via the fixing member.
The image forming apparatus according to claim 4. an extension processing unit that extends a margin area at a leading end of the sheet when the content of the release agent acquired by the acquisition processing unit is equal to or less than a predetermined threshold value;
6. The image forming apparatus according to claim 1. a notification processing unit that notifies a user when the content of the release agent acquired by the acquisition processing unit is outside a predetermined specific range;
6. The image forming apparatus according to claim 1. an adjustment processing unit that adjusts a temperature of the fixing member based on the content of the release agent acquired by the acquisition processing unit;
6. The image forming apparatus according to claim 1. 1. An acquisition method performed in an image forming apparatus including a fixing member that comes into contact with a transfer surface onto which a toner image is transferred in a sheet, and fixes the toner image transferred to the transfer surface onto the transfer surface, the method comprising:
a transfer step of transferring a predetermined specific toner image onto the sheet conveyed via the fixing member;
a detection step of detecting an amount of release agent adhering to a detection target area of the fixing member that has come into contact with the specific toner image;
an acquisition step of acquiring a content of the release agent in the toner used to form the toner image based on a detection result in the detection step;
Acquisition methods include:

Images