JP2017032717A - Image forming apparatus and fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a deterioration in image quality even when a fixing part is replaced before use.SOLUTION: An image forming apparatus 100 comprises: an image forming part 309; a fixing part 150 that can be attached to a main body 100A of the image forming apparatus 100; a rubbing rotator 156 that rubs a surface of a rotator 151 of the fixing part 150; a counting part 301 that counts the number of recording materials to be conveyed to the fixing part 150; a storage part 154 in the fixing part 150 that stores information on the number counted by the counting part 301; and an execution part 301 that, when the number counted by the counting part 301 exceeds a predetermined number, causes the rubbing rotator 156 to execute rubbing processing. The counting part 301 counts the number of recording materials conveyed to the fixing part on the basis of the information in the storage part 154 in the fixing part 150 attached to the main body 100A of the image forming apparatus 100.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an electrophotographic image forming apparatus and a fixing device used in an electrophotographic image forming apparatus.

  An electrophotographic image forming apparatus includes a fixing device (fixing unit) that fixes an unfixed toner image formed on a recording material to the recording material. In order to obtain a higher quality product, a method is known in which a fixing device having a different purpose of use is used in accordance with the size and type of the recording material to be fixed. Japanese Patent Application Laid-Open No. 2004-133620 proposes a method for detecting identification information of a fixing device and notifying a user when a fixing device that is not appropriate for the determined print job specification is recognized.

  On the other hand, when fixing an unfixed toner image in the fixing device, the surface of the fixing member is brought into contact with the end of the recording material (the end in the direction perpendicular to the recording material conveyance direction) with the fixing member (rotating body). It is known to cause minute scratches. If the same spot on the fixing member is repeatedly scratched, the surface property of the fixing member where the scratch is repeatedly applied becomes rough compared to other parts, and there is a risk of uneven glossiness on the image on the fixed recording material. is there. For this reason, a method is known in which the surface of the fixing member is leveled by rubbing the surface of the fixing member (fixing refresh operation) by the rubbing rotator each time the counted number of passing sheets of recording material exceeds a predetermined number. (Patent Document 2).

JP 2011-56945 A JP 2008-40364 A

  However, when a system that uses a plurality of fixing devices is used, the number of recording materials for performing the fixing refresh operation is not properly counted, and printing starts without performing the fixing refresh operation at an appropriate timing. There is a risk of being. As a result, there is a risk of uneven glossiness in the output image.

  Therefore, an object of the present invention is to suppress deterioration in image quality even when the fixing unit is replaced and used.

In order to achieve the above object, the first invention provides:
An image forming apparatus for forming an image on a recording material,
An image forming unit for forming an unfixed toner image on a recording material;
A first rotating body that forms a nip portion for fixing an unfixed toner image formed on a recording material conveyed from the image forming unit, the fixing unit being detachable from a main body of the image forming apparatus And a fixing unit including a second rotating body,
A rubbing rotator for rubbing the surface of the first rotator,
A counting unit for counting the number of recording materials conveyed to the fixing unit;
A storage unit that is provided in the fixing unit and stores information on the number of sheets counted by the counting unit;
An execution unit that causes the rubbing rotary body to perform rubbing processing of the first rotating body when the number counted by the counting unit exceeds a predetermined number;
Have
The counting unit counts the number of recording materials conveyed to the fixing unit based on the information stored in the storage unit of the fixing unit mounted on the main body of the image forming apparatus. It is.

The second invention is
An image forming apparatus for forming an image on a recording material,
An image forming unit for forming an unfixed toner image on a recording material;
A first rotating body that forms a nip portion for fixing an unfixed toner image formed on a recording material conveyed from the image forming unit, the fixing unit being detachable from a main body of the image forming apparatus And a fixing unit including a second rotating body,
A rubbing rotator for rubbing the surface of the first rotator,
A counting unit that counts a value corresponding to the length in the conveyance direction of the recording material conveyed to the fixing unit;
A storage unit that is provided in the fixing unit and stores information of a value counted by the counting unit;
When the value counted by the counting unit exceeds a predetermined value, an execution unit that causes the rubbing rotating body to perform rubbing processing of the first rotating body;
Have
The counting unit has a value corresponding to the length in the conveyance direction of the recording material conveyed to the fixing unit based on the information stored in the storage unit of the fixing unit mounted on the main body of the image forming apparatus. It is characterized by counting.

The third invention is
An image forming apparatus for forming an image on a recording material,
An image forming unit for forming an unfixed toner image on a recording material;
A first rotating body that forms a nip portion for fixing an unfixed toner image formed on a recording material conveyed from the image forming unit, the fixing unit being detachable from a main body of the image forming apparatus And a fixing unit including a second rotating body,
A rubbing rotator for rubbing the surface of the first rotator,
A timing unit for measuring the time for the fixing unit to fix the recording material;
A storage unit that is provided in the fixing unit and stores information of a time measured by the timing unit;
When the time measured by the timer exceeds a predetermined time, an execution unit that causes the rubbing rotary body to perform rubbing processing of the first rotating body;
Have
The counting unit measures the time for the fixing unit to fix the recording material based on the time information stored in the storage unit of the fixing unit attached to the main body of the image forming apparatus. Is.

The fourth invention is:
A fixing device detachable from an image forming apparatus for forming an image on a recording material,
A first rotating body and a second rotating body that form a nip portion for fixing an unfixed toner image formed on a recording material;
A rubbing rotator for rubbing the surface of the first rotator,
A storage unit capable of storing information on the number of recording materials conveyed to the fixing device;
It is characterized by having.

  According to the present invention, it is possible to suppress deterioration in image quality even when the fixing unit is replaced and used.

1 is a cross-sectional view illustrating an example of an image forming apparatus. It is a block diagram which shows an example of a structure of a control system. FIG. 3 is a cross-sectional view illustrating an example of a fixing unit. FIG. 6 is a diagram illustrating a state in which a fixing unit nips and conveys a recording material. It is a figure explaining the gloss nonuniformity by the edge part of a recording material. 6 is a flowchart from when the power switch is turned on until the standby mode is set. It is a flowchart from the state in which the front door is open to the standby mode. It is a flowchart of a refresh sequence. It is a flowchart regarding the count of recording materials. FIG. 6 is a diagram illustrating an example of information held in a memory of a fixing device. It is a flowchart of a refresh sequence. It is a flowchart regarding the count of recording materials.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the components described in this embodiment are merely examples, and the present invention is not limited to only those described in the embodiment.

[Example 1]
(1. Overall configuration of image forming apparatus)
FIG. 1 is a cross-sectional view illustrating an example of an image forming apparatus.

  Here, the overall configuration of the image forming apparatus 100 will be described.

  The image forming apparatus 100 conveys the recording material 102 stored in the recording material storage unit 103 to the image forming unit 309 (FIG. 2), and forms a toner image on the recording material 102. Details of the image forming unit 309 will be described later.

  Thereafter, the image forming apparatus 100 conveys the recording material 102 on which the toner image is formed by the image forming unit 309 to the fixing unit (first fixing device 150, second fixing device 170), and applies heat and pressure. The toner image (unfixed) on the recording material 102 is fixed on the recording material 102. Details of the fixing unit will be described later.

  In the case of single-sided printing, the image forming apparatus 100 discharges the recording material 102 on which image formation has been completed through the image forming unit 309 and the fixing unit to the outside of the image forming apparatus 100 by the flapper 132 guiding the recording material 102 to the discharge path 139. .

  On the other hand, in the case of duplex printing, the image forming apparatus 100 inverts the recording material 102 that has been printed on one side and conveys the recording material 102 to the image forming unit 309 again. Specifically, the fixed recording material 102 is guided by the flapper 132 to the conveyance path 134 and conveyed to the reversing unit 136. When the reverse sensor 135 detects the trailing edge of the recording material 102, the flapper 133 switches the conveyance direction of the recording material 102 to the conveyance path 137. The image forming apparatus 100 conveys the reversed recording material 102 again to the image forming unit 309 and the fixing unit via the conveyance path 137.

  The recording material 102 on which the image formation on both sides is completed is guided to the discharge path 139 by the flapper 132 and discharged to the outside of the image forming apparatus 100.

  Here, the flapper 132 is a switching member that switches whether the recording material 102 that has passed through the image forming unit 309 and the fixing unit is transported to the transport path 134 or discharged to the outside of the image forming apparatus 100.

  The recording material 102 is an image on which an image is formed by the image forming apparatus 100. Examples of the recording material 102 include paper and an OHP sheet.

  The operation unit 180 that functions as a notification unit, a selection unit, a setting unit, and a reception unit includes a display screen and a selection key. The operation unit 180 displays the state of the image forming apparatus 100 on the display screen, and receives an operation instruction from the operator using a selection key. Examples of the operation instruction include setting of the type (surface property, basis weight, size, etc.) of the recording material 102 used for image formation, setting of the number of copies to be printed, setting of single-sided printing / double-sided printing, and the like.

  The power switch 101 is a start switch that starts the image forming apparatus 100.

  The front door 140 serving as an opening / closing unit is an image forming apparatus for mounting the fixing device (first fixing device 150, second fixing device 170) on the mounting unit (first mounting unit 141, second mounting unit 142). 100 is a door provided in an opening of 100A main body 100A.

  Further, the image forming apparatus 100 includes an open / close sensor (optical sensor) 305 (FIG. 2) as a sensor for detecting that the front door 140 is in a closed state. The open / close sensor 305 and the CPU 301 (FIG. 2) function as an open / close detection unit. The front door 140 is provided with a protrusion (not shown), and is inserted into a receiving portion (not shown) of the main body 100A of the image forming apparatus 100 when the front door 140 is closed. The CPU 301 detects that the front door 140 has been closed based on a signal output from the opening / closing sensor 305 when the protrusion is inserted into the receiving portion. On the other hand, when the signal from the open / close sensor 305 is not output, the CPU 301 detects that the front door 140 is open. The CPU 301 detects that the front door 140 is opened based on a signal output from the opening / closing sensor 305 when the front door 140 is opened. On the other hand, when the signal from the opening / closing sensor 305 is not output, the CPU 301 May be configured to detect that the front door 140 is closed.

(2. Configuration of control system)
FIG. 2 is a block diagram showing an example of the configuration of the control system.

  The image forming apparatus 100 (FIG. 1) includes a CPU 301, a RAM 302, a ROM 303, and the like for controlling the operation of the image forming apparatus 100.

  The CPU 301 functioning as a control unit performs basic control of the image forming apparatus 100 by executing a control program stored in the ROM 303. The operation of the flowchart described later is executed by the CPU 301 based on a control program stored in the ROM 303. The CPU 301 uses the RAM 302 as a work area for executing control program processing.

  The CPU 301 is electrically connected to each mechanism to be controlled in addition to the RAM 302 and the ROM 303.

  The CPU 301 also functions as a counter (counter) that counts (counts) the number of recording materials 102 conveyed into the first fixing device 150 and the second fixing device 170. A specific configuration will be described later.

  The external I / F unit 304 is a communication circuit for communicating with an external device connected via a network (for example, a LAN or a WAN). Examples of the external device include a PC and other image forming apparatuses.

  The CPU 301 is connected to the open / close sensor 305 and detects whether or not the front door 140 is in a closed state.

  The sensor group 306 is a sensor on the conveyance path including the sensors 153, 155, 173, and 175 shown in FIG. 1, and is a sensor for the CPU 301 to detect the presence / absence and passage of a recording material.

  The CPU 301 is connected to the operation unit 180. The CPU 301 accepts switching of display contents on the display screen and an operation instruction from the operator through the selection key of the operation unit 180. Further, the CPU 301 displays information such as the operation status of the image forming apparatus 100 and the operation mode set by input from the selection key on the display screen of the operation unit 180.

  The CPU 301 is connected to the timer 307. The timer 307 functions as a timer unit that measures time. As will be described later, it is used for jam detection and measurement of fixing refresh operation time.

  The CPU 301 is connected to the transport unit 308 and controls the transport of the recording material 102. The conveyance unit 308 includes a supply unit that supplies the recording material 102 from the recording material storage unit 103 to the conveyance path, each conveyance roller for conveying the recording material 102 on the conveyance path, and each flapper (see FIG. 1). Flappers 131, 132, 133) shown.

  The CPU 301 is connected to an image forming unit 309, which will be described later, and controls the image forming unit 309.

  The fixing unit memory 310 includes a memory 154 included in the first fixing unit 150 mounted on the image forming apparatus 100 and a memory 174 included in the second fixing unit 170 mounted on the image forming apparatus 100. The CPU 301 is connected to the memories 154 and 174 included in the first fixing device 150 and the second fixing device 170 mounted on the image forming apparatus 100, and performs writing and reading to the memories 154 and 174.

  The CPU 301 is connected to the main body memory 312. The main body memory 312 is a rewritable nonvolatile memory and may be integrated with the RAM 302.

  The CPU 301 is connected to a mechanism group X included in the first fixing device 150 attached to the image forming apparatus 100, and temperature adjustment control (hereinafter also referred to as temperature control) of the first fixing device 150. Control of fixing refresh operation. The mechanism group X indicates a temperature sensor 320, a heater 321, a contact / separation mechanism 322, a motor 323, a refresh roller motor 324, and a refresh roller contact / separation mechanism 325.

  Here, the temperature sensor 320 is a plurality of temperature sensors included in the first fixing device 150, and includes a thermistor 159 (FIG. 3) and a thermistor (not shown) of the pressure belt 152.

  Here, the heater 321 is a plurality of heaters included in the first fixing device 150, and includes a halogen heater 161 (FIG. 3) and a halogen heater (not shown) inside the heating roller 163.

Further, the CPU 301 is connected to the mechanism group X of the second fixing device 170 mounted on the image forming apparatus 100, and temperature adjustment control (hereinafter also referred to as temperature control) and fixing refresh of the second fixing device 170. Control the operation. Since the mechanism group X of the second fixing device 170 is the same as the mechanism group X of the first fixing device 150, the description thereof is omitted by giving the same reference numerals. (In the description of the mechanism group X described above, the first fixing device 150 can be replaced with the second fixing device 170, the pressure belt 152 can be replaced with the pressure roller 172, and the heating roller 163 can be replaced with the pressure roller 172. Just do it.)
In this embodiment, the CPU 301 controls each mechanism. However, for example, a plurality of CPU circuit units that control the operation of each mechanism and a main CPU circuit unit that is connected to the plurality of CPU circuit units and controls the whole may be configured.

(3. Image forming unit)
The image forming apparatus 100 includes stations 120, 121, 122, and 123 as an image forming unit 309 (FIG. 2), an intermediate transfer belt 115 as an intermediate transfer member, and a transfer roller 116 as a transfer unit (FIG. 1). ).

  Stations 120, 121, 122, and 123 form yellow, magenta, cyan, and black toner images on the intermediate transfer belt 115, respectively.

  The configuration of the station 120 will be described. A photosensitive drum 110 as an image carrier rotates counterclockwise in FIG. A primary charger 111 as a charging unit charges the photosensitive drum 110 to a uniform surface potential. The laser unit 112 as an exposure unit has a light source 113 that outputs laser light, and forms an electrostatic latent image on the photosensitive drum 110 according to the document image. A developing device 114 as a developing unit develops the electrostatic latent image formed on the photosensitive drum 110 with toner to form a toner image. Since the configuration of the stations 121, 122, and 123 is the same as that of the station 120, description thereof is omitted.

  The toner images formed by the stations 120, 121, 122, and 123 are transferred onto the intermediate transfer belt 115. The transfer roller 116 transfers the toner image on the intermediate transfer belt 115 to the recording material 102 conveyed from the recording material storage unit 103.

(4. Fixing part)
(4.1. Tandem fixing)
The first fixing device 150 and the second fixing device 170 as fixing units fix the toner image transferred to the recording material 102 to the recording material 102 by applying heat and pressure to the recording material 102 (FIG. 1).

  The second fixing device 170 is arranged downstream of the first fixing device 150 with respect to the conveyance direction of the recording material 102. The second fixing device 170 gives gloss to the toner image on the recording material 102 fixed by the first fixing device 150, or has a large basis weight that requires a large amount of heat for fixing processing (for example, thick paper) The first fixing device 150 alone is used for the purpose of compensating for the heat quantity that is insufficient.

  On the other hand, when fixing is possible only with the first fixing device 150, the second fixing device 170 does not have to be used. Therefore, the recording material 102 does not pass through the second fixing device 170 for the purpose of reducing energy consumption. It is conveyed on the conveyance path 130. For example, there is a case where the recording material 102 is plain paper or thin paper and the setting for adding a lot of gloss is not made. Whether the recording material 102 is conveyed to the second fixing device 170 (tandem fixing route) or the recording material 102 is conveyed by bypassing the second fixing device 170 (bypass route) is controlled by the CPU 301 switching the flapper 131. To do.

(4.2. Configuration of fixing unit)
The first fixing device 150 and the second fixing device 170 are detachably provided on a first mounting portion 141 and a second mounting portion 142 (mounting portion) provided in the image forming apparatus 100, respectively. The first fixing device 150 and the second fixing device 170 can be replaced with a fixing device having the following configuration.

  The first fixing device 150 is provided with a memory 154 as a storage unit. The second fixing device 170 is provided with a memory 174 as a storage unit. Details will be described later.

  Further, as jam detection units, the first fixing device 150 is provided with sensors 153 and 155, and the second fixing device 170 is provided with sensors 173 and 175. In each fixing device, the sensors 155 and 175 on the upstream side in the conveyance direction of the recording material 102 also function as a detection unit that detects that the recording material 102 has been conveyed to each fixing device. Details will be described later.

  FIG. 3 is a cross-sectional view showing an example of the fixing unit. The detailed configuration of the first fixing device 150 will be described with reference to FIG.

  The first fixing device 150 includes a fixing roller 151 (fixing member) (rotating member) and a pressure belt 152 (pressure member) (rotating member), which fix the toner image on the recording material 102. A nip portion is formed to

  The fixing roller 151 is a hollow roller, and a halogen heater 161 is incorporated therein as a heating source. A thermistor 159 as a temperature detection unit is a sensor that measures the temperature of the fixing roller 151. The CPU 301 controls ON / OFF of the halogen heater 161 based on the temperature information detected by the thermistor 159. This is for maintaining and adjusting the temperature of the fixing roller 151 at a predetermined temperature. The predetermined temperature includes an error.

  The pressure belt 152 is an endless belt supported by three rollers. A pressure pad 164 that presses the pressure belt 152 toward the fixing roller 151 is provided on the inner peripheral surface of the pressure belt 152. The heating roller 163, which is one of the three rollers, is a hollow roller and incorporates a halogen heater (not shown) as a heating source therein to heat the pressure belt. Similarly to the fixing roller 151, the CPU 301 controls the halogen heater (not shown) of the heating roller 163 based on temperature information detected by a thermistor (not shown) as a sensor for measuring the temperature of the pressure belt 152. As a result, the temperature of the pressure belt 152 is maintained and adjusted to a predetermined temperature.

  The fixing roller 151 is rotationally driven by a motor 323 (FIG. 2) as a drive source, and conveys the recording material 102 in the direction of arrow A in FIG. The pressure belt 152 is configured to rotate following the fixing roller 151.

  Further, the first fixing device 150 moves the pressure belt 152 so that the fixing roller 151 and the pressure belt 152 are in contact with each other to form a contact state and a separation state in which the nip portion is formed. It has a mechanism 322 (FIG. 2). In this embodiment, the contact / separation mechanism 322 moves the pressure belt 152, but the fixing roller 151 may be moved, or both the fixing roller 151 and the pressure belt 152 may be moved. Good.

  On the other hand, the second fixing device 170 has a pressure roller 172 instead of a pressure belt as a pressure member, and the fixing roller 171 (fixing member) and the pressure roller 172 (pressure member) are toner on the recording material 102. A nip portion for fixing the image is formed (FIG. 1). The pressure roller 172 is a hollow roller and incorporates a halogen heater (not shown) as a heating source. The pressure roller 172 includes a thermistor (not shown) as a temperature sensor. As the CPU 301 controls a thermistor (not shown) and a halogen heater (not shown), the temperature of the pressure roller 172 is maintained and adjusted to a predetermined temperature.

  Since the other configuration of the second fixing device 170 is the same as that of the first fixing device 150, description thereof is omitted.

In the following description, the first fixing device 150 will be described, but the same applies to the second fixing device 170 unless otherwise specified. (In this case, the configuration related to the first fixing device 150 may be replaced with the configuration related to the second fixing device 170).
In this embodiment, the first fixing device 150 and the second fixing device 170 have different configurations on the pressure side, but may have the same configuration. That is, the configuration of the pressure side of both the first fixing device 150 and the second fixing device 170 may be a pressure belt, or the pressure side of both the first fixing device 150 and the second fixing device 170. The configuration may be a pressure roller. Further, the configuration on the pressure side of the first fixing device 150 may be a pressure roller, and the configuration on the pressure side of the second fixing device 170 may be a pressure belt.

(4.3. Refresh roller)
Next, the refresh roller 156 as a rubbing rotator for rubbing the surface of the rotator will be described. An example in which the surface of the fixing roller 151 of the first fixing device 150 is rubbed will be described. The same applies to the second fixing device 170, and thus the description thereof is omitted.

  In this embodiment, the refresh roller 156 performs a rubbing process on the surface of the fixing roller 151. The refresh roller 156 is disposed so as to be able to come into contact with and separate from the fixing roller 151, and can slide on the peripheral surface of the fixing roller 151. The refresh roller 156 is a roughing roller that has abrasive grains fixed on its peripheral surface and is rotationally driven with a peripheral speed difference from the fixing roller 151 to roughen the peripheral surface of the fixing roller 151.

  Specifically, the refresh roller 156 is provided with a rubbing layer in which abrasive grains are closely bonded via an adhesive layer on the peripheral surface of a stainless steel pipe (SUS304) having an outer diameter of 12 mm.

  Various types of abrasive grains or a mixture of various types of abrasive grains that are commercially available can be bonded with an adhesive layer to form a rubbing layer. Examples of commercially available abrasive grains are aluminum oxide, aluminum hydroxide oxide, silicon oxide, cerium oxide, titanium oxide, zirconia, lithium silicate, silicon nitride, silicon carbide, iron oxide, chromium oxide, antimony oxide, diamond, etc. is there.

  Here, aluminum oxide abrasive grains (alumina-based abrasive grains, alundum, molundum) were used as the abrasive grains of the rubbing layer. Aluminum oxide abrasive grains are the most widely used abrasive grains, which are sufficiently harder than the fixing roller 151, have an acute angle shape, and are excellent in machinability, and are suitable as a rubbing layer. In order for the surface roughness of the fixing roller 151 after the rubbing treatment by the refresh roller 156 to satisfy the effect of the fixing refresh operation described later, the grain size of the abrasive grains in the rubbing layer is preferably 5 μm or more and 20 μm or less. Has been confirmed.

  The refresh roller 156 moves so that the refresh roller contact / separation mechanism 325 can take a contact state in contact with the fixing roller 151 and a separation state in which the refresh roller 156 is separated from the fixing roller 151. The CPU 301 controls the refresh roller contact / separation mechanism 325 to control the contact / separation state of the refresh roller 156.

  The refresh roller 156 has a refresh roller motor 324 as a drive source, and is driven to rotate with a circumferential speed difference from the fixing roller 151. The CPU 301 controls the refresh roller motor 324 to control the rotation and stop of the refresh roller 156. The refresh roller 156 may have a relative speed in the same direction as the movement direction of the surface of the fixing roller 151 or may have a relative speed difference in the opposite direction.

  The refresh roller 156 is rotatively driven by the motor 324 of the refresh roller while being in contact with the fixing roller 151 by the refresh roller contact / separation mechanism 325, so that the peripheral surface of the fixing roller 151 is rubbed. The CPU 301 controls the refresh roller contact / separation mechanism 325 and the refresh roller motor 324 to cause the refresh roller 156 to rub the fixing roller 151 and execute a fixing refresh operation for bringing the peripheral surface of the fixing roller 151 closer to a uniform surface state.

(5. Uneven gloss due to the edge of the recording material)
Here, the reason why the fixing refresh operation is necessary will be described.

  In the fixing roller 151, an elastic layer of silicon rubber having a rubber hardness of 20 ° (JIS-A1 kg load) and a thickness of about 1.0 mm is disposed around a base layer made of aluminum having an outer diameter of 68 mm. The surface of the elastic layer is covered with a release layer made of a fluororesin tube having a thickness of 30 μm.

  When the image forming apparatus 100 forms an image, the first fixing device 150 forms a nip portion between the fixing roller 151 and the pressure belt 152.

  As in this embodiment, when toner having high meltability is used in the oilless fixing method, the surface state of the fixing roller 151 is easily reflected on the surface of the toner layer on the recording material 102. That is, the influence of fine irregularities on the surface of the fixing roller 151 is likely to appear in the surface state of the output image by the fixing process. Such a property is called a fixed image mapping property. When the meltability of the toner is improved and the image clarity is improved, it is important to maintain the surface state of the fixing roller 151 in order to form a high-quality image with high glossiness.

  The fixing roller 151 in the initial state is a uniform mirror surface as a whole. Here, the surface roughness (ten-point average roughness) Rz of the peripheral surface was about 0.1 μm to 0.3 μm. Hereinafter, the surface roughness Rz is a ten-point average roughness (based on JIS standards) measured using a surface roughness measuring instrument SE-3400 of Kosaka Laboratory. The measurement conditions are feed rate: 0.5 mm / sec, cut-off: 0.8 mm, and measurement length: 2.5 mm.

  FIG. 4 is a diagram illustrating a state in which the fixing unit nips and conveys the recording material.

  When the fixing process of the recording material 102 is accumulated in the first fixing device 150, the surface state of the fixing roller 151 changes due to contact with the end of the recording material 102, paper dust, offset toner, and the like, and the fixing roller 151. The surface gradually becomes rough. The recording material 102 repeatedly passes through a fixed position in the direction of the rotation axis of the fixing roller 151, so that the (I) non-passing portion, (II) passing portion, and (III) the fixing roller 151 in the boundary region of the fixing roller 151. The surface roughness is different.

  Here, the end portion of the recording material 102 is an end portion in a direction perpendicular to the conveying direction of the recording material 102 and is hereinafter referred to as an edge portion.

FIG. 5 is a diagram for explaining uneven glossiness due to the edge of the recording material. In the enlarged view in FIG. 5 (the figure showing the scratches on the fixing roller), the left portion (white portion) is (I) the non-passing portion, and the central portion (coarse dot portion) is (III) the boundary region. The right part (the part painted darkly) shows the passing part (II).
(I) The non-passing portion is an area through which the recording material 102 does not pass and does not contact the recording material 102. (I) In the non-passing portion, the surface of the fixing roller 151 abuts exclusively on the surface of the pressure belt 152.
(II) The passing portion is an area through which the recording material 102 passes, and the recording material 102 contacts. (II) In the passing portion, the fibers of the recording material 102, the filler of the recording material 102, the external additive of the developer present on the recording material 102 together with the toner come into contact, and the surface of the fixing roller 151 is gradually roughened. .
(III) Since the boundary region is located at the boundary between the passing portion and the non-passing portion and repeatedly contacts the edge portion of the recording material 102, (II) the surface roughness is rougher than that of the passing portion.

That is, the surface roughness of the fixing roller 151 is obtained by repeatedly passing the recording material 102 through a certain position in the direction of the rotation axis of the fixing roller 151.
(III) boundary region> (II) passing portion> (I) non-passing portion.

  In the process of fixing the unfixed toner image on the recording material 102, the minute surface shape of the fixing roller 151 is transferred to the surface of the fixed image after the fixing process.

  As shown in FIG. 5, if the surface state is different between the (II) passing portion of the fixing roller 151 and the (III) boundary region, a difference in surface state is generated on the surface of the fixed image, and the fixed image is glossy. Unevenness (gross unevenness) occurs. In the figure showing the gloss unevenness on the image (on the recording material) in FIG. 5, the left portion (dot portion) corresponds to (I) the non-passing portion, and the central portion (white portion) corresponds to (III). A location corresponding to the boundary region and a right portion (a darkly painted portion) indicate (II) a location corresponding to the passing portion. In addition, since the width of the (III) boundary region is as narrow as about 1 to 2 mm, the gloss difference that occurs between (I) the non-passing portion and (II) the passing portion gives an impression as gloss unevenness (gross unevenness) in a wide region. Is big.

  Further, the gloss unevenness of the fixed image also depends on the paper type of the recording material 102. For example, even if the gloss unevenness is at a level that is not visible on plain paper, the uneven gloss becomes noticeable in a fixed image on glossy coated paper with high surface smoothness and high image quality. In a fixed image on gloss coated paper, a low-gloss streak stands out at a position corresponding to the (III) boundary region (rougher than other regions) of the fixing roller 151, and (I) non-passing portion and (II) passing through The difference in gloss that occurs between the parts is also noticeable. Therefore, the gloss unevenness of the fixed image becomes remarkable as a whole.

  As described above, the roughness of the surface of the fixing roller 151 differs between (I) the non-passing portion and (II) the passing portion, thereby causing a difference in glossiness on the fixed image. In particular, the (III) boundary region tends to be rough, and a difference in glossiness occurs between (I) the non-passing portion and (II) the passing portion.

  Although the first fixing device 150 has been described as an example, the same applies to the second fixing device 170, and thus the description thereof is omitted.

(6. Fixing refresh operation)
As described above, when the recording material 102 repeatedly passes through the nip portion, the surface state is nonuniform in the longitudinal direction of the fixing roller 151 (the direction of the rotation axis), which may lead to uneven gloss.

  Therefore, in the image forming apparatus 100, after a predetermined number of recording materials 102 are conveyed to the first fixing device 150, a fixing refresh operation for improving the surface state of the fixing roller 151 is executed. Hereinafter, the first fixing device 150 will be described as an example, but the same applies to the second fixing device 170, and thus description thereof will be omitted.

  The refresh roller 156 rubs against the fixing roller 151 in the fixing refresh operation. As a result, the surface roughness of the fixing roller 151 is improved by leveling the surface roughness of the fixing roller 151 in the longitudinal direction.

  The refresh roller 156 roughens the surface of the fixing roller 151 roughened by the passage of the recording material 102 and the surface of the fixing roller 151 not relatively roughened to a desired level by applying a number of fine scratches. That is, the refresh roller 156 reduces the difference in the surface state of the entire fixing roller 151.

  This eliminates the low gloss streak at the position on the image corresponding to the edge portion ((III) boundary region) and (I) the gloss difference between the non-passing portion and (II) passing portion. That is, the surface state of the fixing roller 151 can be improved (improved). By making the scratches made by the refresh roller 156 small and many rubbing scratches, the scratches made by the refresh roller 156 on the fixing roller 151 become difficult to see on the image. In other words, the scratch due to the end of the recording material 102 on the fixing roller 151 is superimposed on the scratch due to the end of the recording material 102 on the surface of the fixing roller 151, so that the scratch due to the end of the recording material 102 on the fixing roller 151. Make it difficult to see above.

  The purpose of rubbing by the refresh roller 156 is to make fine rubbing scratches on the surface of the fixing roller 151, and not to scrape the surface of the fixing roller 151 to give a new surface. The refresh roller 156 scratches the surface of the fixing roller 151 without substantially removing the surface. The rubbing by the refresh roller 156 is not at the level at which the fixing roller 151 is polished, but at the level of embossing that returns the uneven state of the surface of the fixing roller 151 to the initial state.

(6.1. Recording material counting method)
In this embodiment, the number of the recording material 102 conveyed to the first fixing device 150 is used as a reference for executing the fixing refresh operation. Specifically, the predetermined number of sheets is set to 500, and after the number of recording materials 102 conveyed to the first fixing device 150 (hereinafter referred to as the number of conveyed sheets) exceeds 500, the fixing refresh operation is performed. Is executed.

  In this example, the CPU 301 functioning as a counting unit (counter) counts the number of conveyed sheets on the RAM 302 based on the signal from the sensor 155.

  A sensor 155 serving as a detection unit is a sensor provided in the first fixing device 150, and is provided upstream of the nip portion of the first fixing device 150 in the transport direction. The sensor 155 is a sensor for detecting that the recording material 102 has been conveyed to the first fixing device 150, and an optical sensor, for example, is used. The CPU 301 detects that the recording material 102 has been conveyed to the first fixing device 150 by receiving a signal output by the sensor 155 when the recording material 102 passes.

  Each time the CPU 301 detects that the recording material 102 has been conveyed to the first fixing device 150, the CPU 301 counts up the value (count value) on the RAM 302, thereby recording the recording material conveyed to the first fixing device 150. The number of materials 102 is managed.

  Then, the CPU 301 causes the fixing refresh operation to be executed after the count value exceeds a value indicating a predetermined number (for example, 500).

  Note that the method of counting the number of recording materials 102 conveyed to the first fixing device 150 is not limited to this.

  For example, the number of recording materials 102 conveyed to the first fixing device 150 may be counted based on the number of printed sheets specified in the print job received by the operation unit 180. For example, when the designated print job is 30 sheets, the CPU 301 sequentially conveys the 30 recording materials 102 to the first fixing device 150. At the same time, the CPU 301 sequentially counts up the count values on the RAM 302 (for a total of 30 sheets).

(6.2. Fixing refresh operation)
The fixing refresh operation performed after the predetermined number of recording materials 102 are conveyed to the first fixing device 150 will be described more specifically.

  In the fixing refresh operation, the CPU 301 controls the refresh roller motor 324 to rotate the refresh roller 156. At this time, the CPU 301 controls the refresh roller contact / separation mechanism 325 to bring the refresh roller 156 into contact with the fixing roller 151. As a result, the refresh roller 156 rubs the surface of the fixing roller 151.

  When the CPU 301 rubs the fixing roller 151 by the refresh roller 156 for a predetermined time, the CPU 301 moves the refresh roller 156 away from the fixing roller 151.

  Here, the timer 307 built in the image forming apparatus 100 measures the time (30 seconds in this embodiment) for which the refresh roller 156 performs the rubbing process. The winding time may be measured by providing a clock on the image forming apparatus 100 and counting based on the time output by the CPU 301.

  When the predetermined time has elapsed, the CPU 301 separates the refresh roller 156 from the fixing roller 151 and stops driving the refresh roller. This completes the fixing refresh operation.

(7. Effect of fixing refresh operation)
In the fixing refresh operation, the refresh roller 156 has innumerable sliding scratches (thin directional concave portions) such that the surface roughness Rz (10-point average roughness) of the fixing roller 151 is 0.5 μm or more and 2.0 μm or less. Are formed along the rotation direction of the fixing roller 151. The refresh roller 156 forms sliding scratches (concave portions) having a width of 10 μm or less at a density of 10 or more per 100 μm along the rotation axis direction of the fixing roller 151.

  When the refresh roller 156 forms a large number of fine rubbing scratches on the entire peripheral surface of the fixing roller 151, the difference in surface condition between (I) non-passing portion, (II) passing portion, and (III) boundary region is caused. As a result, the non-uniformity of the surface state on the fixing roller 151 is not noticeable.

  As a result, the surface condition of the fixing roller 151 decreases to a level at which the gloss difference on the transferred fixed image cannot be visually recognized, and the effect of scratches on the edge of the recording material 102 formed on the fixing roller 151 is also visually recognized on the image. It becomes difficult. Further, the low gloss streak at the position corresponding to the (III) boundary region of the fixed image is substantially eliminated, and the gloss unevenness generated between the (I) non-passing portion and the (II) passing portion of the fixed image becomes inconspicuous. .

  Specifically, the surface roughness Rz (10-point average roughness) on the image (toner portion on the recording material 102) of the recording material 102 that has been subjected to the fixing process by the fixing roller 151 that rubbed the surface is 0. It was about 5 μm or less, and it was difficult to visually recognize a gloss difference at this level. Further, with respect to the density of rubbing scratches, if there are several sparsely, it becomes easy to visually recognize as streaks, but if there are streaks in high density (high frequency), it becomes difficult to visually recognize gloss differences.

  A rubbing time (30 seconds in this embodiment) of the refresh roller 156 suitable for restoring the surface state on the fixing roller 151 is preset (stored in the ROM 303). In addition, a predetermined number of sheets (500 sheets in this embodiment) serving as a reference for executing the fixing refresh operation is also preset (stored in the ROM 303). These values of time and number of sheets are not limited to the above example, and may be set as appropriate according to the configuration of the apparatus.

(8. Standby mode)
The standby mode refers to a period in which the image forming apparatus 100 can start image formation and is waiting for a print command (print job) from an operator. An operation unit 180 serving as a reception unit is configured to set the type of recording material 102 (surface property, basis weight, size, etc.) used for image formation, the number of copies to be printed, and single-sided / double-sided printing settings. Accept print jobs.

  When the power switch 101 of the image forming apparatus 100 is turned on, the image forming apparatus 100 prepares to start image formation of the first fixing device 150, the second fixing device 170, the image forming unit 309, and the like. Perform the operation (start-up operation). Even when the image forming apparatus 100 is ready to start image formation (that is, even when the start-up operation is completed), when there is no print job to be started, or after execution of the print job is finished, the mode is shifted to the standby mode. To do.

  As the image forming apparatus 100 becomes ready to start image formation, the CPU 301 displays a message such as “Can print” on the operation unit (notification unit) 180.

  In the present embodiment, when the standby mode is set, temperature control (for example, the fixing roller 151 and the second fixing device 151) is performed so that printing can be started immediately after receiving a print job. The temperature control of the pressure belt 152 is continued.

  Note that if a print reservation is made during the start-up operation in which the image forming apparatus 100 is ready to start image formation, the reserved print job processing (image formation processing) is started immediately without shifting to the standby mode. Let

  For example, when a jam occurs during the execution of a print job, the image forming apparatus 100 stops operating and interrupts the print job. In this case, a start-up operation is performed so that the image forming apparatus 100 can start image formation after the jam is eliminated. When resuming a job that has been interrupted in this way, the job that has been interrupted upon completion of the start-up operation is resumed without shifting to the standby mode.

(9. Fixing unit replacement system)
A fixing device replacement system will be described.

  The image forming apparatus 100 can print on a plurality of types and sizes of recording materials 102. In the image forming apparatus 100 of this embodiment, in order to obtain a higher quality product, the purpose of use varies depending on the type of the recording material 102 to be fixed among the image-forming recording materials 102 and the preference of the operator. The fixing device can be replaced and used.

  For example, there is a case where the fixing device to be used is changed depending on whether an envelope is used as the recording material 102 or not. When an envelope is used as the recording material 102, a fixing device dedicated to the envelope is used. Since the envelope is bound in a bag shape, wrinkles are likely to occur due to the pressure applied during the fixing process. Therefore, it is desirable to use an envelope-dedicated fixing device in which the pressure between the fixing roller 151 and the pressure belt 152 (hereinafter also referred to as nip pressure) is adjusted according to the envelope.

  Although the first fixing device 150 has been described as an example, the same applies to the second fixing device 170.

  As described above, with the image forming apparatus 100 according to the present exemplary embodiment, the operator can use the fixing device according to the type and preference of the recording material 102 that the operator wants to print.

  When replacing the fixing device, the operator opens the front door 140 and takes out the fixing device already attached to the image forming apparatus 100. Then, the operator attaches a fixing device different from the taken-out fixing device to the image forming apparatus 100 and closes the front door 140. In this embodiment, the fixing devices that can be replaced as described above are both the first fixing device 150 and the second fixing device 170.

(10. Fixer memory)
In this embodiment, since a fixing device replacement system is employed, the first fixing device 150 is provided with a memory 154 as a storage unit, and the second fixing device 170 is provided with a memory 174 as a storage unit. Provided. The memories 154 and 174 are rewritable nonvolatile memories (storage units) represented by EEPROM, flash memory and the like. Further, not only the first fixing device 150 and the second fixing device 170 mounted on the image forming apparatus 100 but also a fixing device prepared outside the image forming apparatus 100 as a fixing device for replacement. Similarly, a memory is provided.

  Here, the reason why the memory is provided in the fixing device group including the first fixing device 150 and the second fixing device 170 is to solve the following problems. That is, there is a problem that occurs when the first fixing device 150 and / or the second fixing device 170 is once taken out from the image forming apparatus 100 and the taken out fixing device is attached to the image forming apparatus 100 again. This is to solve the problem. Hereinafter, the first fixing device 150 will be described as an example. Since the same applies to the second fixing device 170, the description thereof is omitted.

(10.1. Specific situations)
Specifically, the following situations are assumed. The replacement target is the case of the first fixing device 150.

  For example, it is assumed that the first fixing device 150 performs the fixing refresh operation after 500 recording materials 102 are conveyed. It is assumed that when the fixing device A that is not dedicated to the envelope is installed as the first fixing device 150, 450 print jobs (for example, image formation on A4 size plain paper, vertical feeding) are performed. Thereafter, when printing of the envelope becomes necessary, the fixing device A is taken out from the image forming apparatus 100 in order to replace it with the fixing device B dedicated to the envelope. The operator executes 50 print jobs in a state where the fixing device B is mounted as the first fixing device 150.

  Conventionally, the CPU manages the number of sheets of recording material conveyed to the first fixing device with a counter provided in the main body of the image forming apparatus, thereby executing a fixing refresh operation after the number of conveyed sheets exceeds a predetermined number. Yes. Therefore, when the fixing device A is replaced with the fixing device B, the CPU transfers the number of sheets conveyed to the first fixing device to 500 at the timing when the fixed fixing device B has finished 50 print jobs. Therefore, only the fixing device B is caused to execute the fixing refresh operation. That is, the CPU determines that the fixing refresh operation after 500 recording materials have been conveyed is finished.

  When the recording material other than the envelope (for example, plain paper) is to be printed at a later date, the operator mounts the fixing device A again. It is assumed that the operator has executed 50 print jobs (image formation on A4 size plain paper. Vertical feed).

  Since the fixing device A has already transported 450 recording materials last time, the fixing roller that has completed 50 print jobs is in a state where the surface state is non-uniform in the longitudinal direction. If the next print job (for example, image formation on A3 size plain paper) is performed in this state, glossiness unevenness occurs in the output image, and the image quality is greatly reduced.

  Therefore, in this embodiment, the memory 154 is provided in the first fixing device 150. As a result, the first fixing device 150 and the fixing device for replacement can each store information on the number of recording materials 102 conveyed to the fixing device. For example, as illustrated in FIG. 10, the CPU 301 causes the memory 154 to hold information on the number of conveyed recording materials 102 (the number of conveyed sheets). Here, FIG. 10 is a diagram showing an example of information held in the memory of the fixing device.

(10.2. Counting based on information in the memory of the fixing device)
The CPU 301 serving as a counting unit counts the number of sheets of recording material 102 (the number of conveyed sheets) conveyed to the first fixing device 150 based on information in the memory 154.

  The CPU 301 can cause the first fixing device 150 to perform the fixing refresh operation based on the more accurate information on the number of sheets conveyed by counting the number of sheets conveyed based on the information in the memory 154. It is possible to suppress deterioration in the image quality of the recording material 102 to be output.

  The configuration of the present embodiment will be specifically described.

  First, the CPU 301 acquires information on the number of sheets from the memory 154 when the first fixing device 150 is remounted by the operator.

  Here, when the first fixing device 150 is replaced, the operator opens the front door 140, pulls out the already-attached first fixing device 150 from the image forming apparatus 100, and mounts the fixing device. Change. Then, the first fixing device 150 is moved in the direction opposite to that when being pulled out and set in the image forming apparatus 100, and the front door 140 is closed.

  The CPU 301 detects that the front door 140 is closed based on a signal from the open / close sensor 305. When the CPU 301 detects that the front door 140 is closed, the CPU 301 accesses the memory 154 of the first fixing device 150. From this, it is confirmed whether or not the first fixing device 150 is attached. If the CPU 301 cannot access the memory 154, the CPU 301 determines that the first fixing device 150 is not attached. Note that the method of determining (confirming) whether or not the first fixing device 150 is attached is not limited to this. For example, the conductive state or non-conductive state between the image forming apparatus 100 and the first fixing device 150 is used. It is good also as a structure which determines (confirms) by detecting.

  When the power switch 101 is replaced with the power switch 101 turned off, the open / close sensor 305 cannot detect that the front door 140 is closed. Therefore, the CPU 301 accesses the memory 154 of the first fixing device 150 when the power switch 101 is turned on. From this, it is confirmed whether or not the first fixing device 150 is attached. If the CPU 301 cannot access the memory 154, the CPU 301 determines that the first fixing device 150 is not attached.

  Next, when the information acquired from the memory 154 exceeds the predetermined number as the first fixing device 150 is remounted, the CPU 301 causes the refresh operation to be executed. When the information acquired from the memory 154 does not exceed the predetermined number, the CPU 301 determines the number of conveyed sheets in which the recording material 102 is conveyed to the first fixing device 150 from the continuation of the number of conveyed sheets stored in the memory 154. Is counted on the RAM 302. For example, if the information acquired from the memory 154 is 30 sheets, the CPU 301 counts 31, 32, 33,... On the RAM 302 every time the recording material 102 is conveyed to the first fixing device 150. When the count value on the RAM 302 exceeds a predetermined number, the CPU 301 executes a fixing refresh operation. In this embodiment, the sensor 155 detects that the recording material 102 has been conveyed to the first fixing device 150 as described above. When the fixing refresh operation is executed, the CPU 301 resets the count value on the RAM 302.

  The count number per sheet may be weighted according to the length of the recording material 102 in the transport direction. That is, as a reference for executing the fixing refresh operation, the value held in the memory 154 or counted on the RAM 302 corresponds to the number of sheets of recording material 102 (the number of sheets conveyed) conveyed to the first fixing device 150. Any value can be used. In this case, similarly to the main scanning length information of the recording material 102, the length information in the conveyance direction of the recording material 102 is acquired from the content of the print job accepted by the CPU 301. The degree of weighting is stored in the ROM 303 in advance so that the CPU 301 can acquire it.

  Note that the method of counting the number of transported sheets based on the information in the memory 154 is not limited to this. For example, the CPU 301 updates and records information on the number of conveyed sheets in the memory 154 of the first fixing device 150 each time the recording material 102 is conveyed into the first fixing device 150, so that the first fixing device 150. A configuration may be adopted in which the number of the recording materials 102 conveyed therein is counted. The CPU 301 counts based on the information on the number of conveyed sheets stored in the memory 154. Accordingly, in this case as well, the CPU 301 as a counting unit counts the number of sheets of recording material 102 (the number of sheets conveyed) conveyed to the first fixing device 150 based on the information in the memory 154.

  Further, for example, the CPU 301 may be configured to count the number of transported sheets so as to be a predetermined number in combination with the number of transported sheets acquired from the memory 154. Specifically, when the information acquired from the memory 154 is 30 sheets, the CPU 301 reads 1, 2, 3,... On the RAM 302 every time the recording material 102 is conveyed to the first fixing device 150. Count. When the predetermined number of sheets is 500, the CPU 301 determines that the number of conveyed sheets exceeds the predetermined number in response to the count value on the RAM 302 becoming 470.

  The reference for executing the fixing refresh operation may not be information on the number of recording materials 102 conveyed to the first fixing device 150. For example, it may be a total value of the lengths of the recording material 102 conveyed to the first fixing device 150 in the conveyance direction. In this case, the memory 154 holds a total value of the lengths in the conveyance direction of the recording material 102 conveyed to the first fixing device 150. The CPU 301 adds (counts) the value in the conveyance direction of the recording material 102 conveyed to the first fixing device 150 to the value acquired from the memory 154. If this value exceeds a predetermined length, the CPU 301 executes a fixing refresh operation.

  Further, for example, as a reference for executing the fixing refresh operation, the time during which the fixing roller 151 has been performing the fixing process may be measured and held in the memory 154. In this case, the reference for executing the fixing refresh operation is also time (for example, 4000 seconds). For example, a timer (timer) 307 measures the time during which the fixing roller 151 and the pressure belt 152 are in contact with each other.

  Specifically, the CPU 301 sets the time of the fixing process acquired from the memory 154 as an initial value of the timer 307. The timer 307 measures the time during which the fixing roller 151 and the pressure belt 152 are in contact from the continuation of the set initial value. When the value of the timer 307 exceeds a predetermined time, the CPU 301 executes a fixing refresh operation. Note that the initial value of the timer 307 may be set to zero, and the CPU 301 may add the time measured by the timer 307 and the time stored in the memory 154 to measure the time during which the fixing roller 151 has performed the fixing process. .

  In addition, as information held in the memory 154, when the information on the number of transported sheets is zero (no data), the CPU 301 determines that the information on the number of transported sheets is stored.

  Further, the memory 154 may store information other than the information on the number of transported sheets. For example, information indicating the use and type of the first fixing device 150 such as an envelope or an A4 size may be stored.

(10.3. Count for each width size)
Further, in this embodiment, the number of transported sheets is stored for each length of the recording material 102 in the direction perpendicular to the transporting direction of the recording material 102. Here, the length of the recording material 102 in the direction perpendicular to the conveyance direction of the recording material 102 is referred to as a main scanning length (or width size). FIG. 10 is an example in which the number of transported sheets is stored for every 5 mm of the main scanning length of the recording material 102.

  As described above, the (III) rough boundary area is generated when the edge portion of the recording material 102 repeatedly contacts a certain position in the direction of the rotation axis of the fixing roller 151. That is, it occurs when the number of conveyed recording materials 102 having the same main scanning length increases.

  Further, in the fixing refresh operation, the surface state of the entire fixing roller 151 ((I) non-passing portion, (II) passing portion, (III) boundary region) is leveled. The unevenness of the surface state of the fixing roller 151 due to the edge portion of the recording material 102 having another main scanning length is also leveled.

  Therefore, in this embodiment, the number of the recording materials 102 conveyed to the first fixing device 150 is stored in the memory 154 for each main scanning length of the recording material 102 of 5 mm. After the number of transported recording materials 102 of any main scanning length exceeds a predetermined number (500 in this example), the CPU 301 executes a fixing refresh operation. Thereafter, the count of the number of conveyed sheets for all main scanning lengths is set to zero. Again, when the number of conveyed recording materials 102 of any main scanning length exceeds a predetermined number (500 in this example), the CPU 301 executes a fixing refresh operation.

  Here, the information on the main scanning length of the recording material 102 is acquired from the contents of the print job accepted by the CPU 301. When receiving a print job from the operator, the operation unit 180 also receives an instruction for the size (for example, A3) of the recording material 102 on which an image is formed as one of the contents.

  As a result, uneven glossiness of the output image can be suppressed, and the frequency of the fixing refresh operation can be reduced as compared with the case where the fixing refresh operation is performed regardless of the main scanning length of the recording material 102.

(11. Control flow)
In this embodiment, the CPU 301 counts the number of conveyed recording materials 102 conveyed to the first fixing device 150 for each main scanning length (for each width size), and stores it in the memory 154. When the count value of the number of transported recording materials 102 of any main scanning length exceeds a predetermined value during printing, the fixing refresh operation is executed after the execution of the print job (image forming process), and then the standby Transition to mode. That is, when the count value at the end of the image forming process exceeds a predetermined value, the fixing refresh operation is executed after the print job is finished. In addition, when any of the count values of the number of conveyed sheets 102 of the main scanning length acquired from the memory 154 when the power is turned on or when the front door 140 is closed, the CPU 301 exceeds a predetermined value. After executing the fixing refresh operation, the mode shifts to the standby mode.

  The above will be described in more detail with reference to the flowcharts of FIGS.

  These flowcharts are performed when the CPU 301 functioning as an execution unit (recording unit) controls the operation of various mechanisms of the image forming apparatus 100 based on a control program stored in the ROM 303. The first fixing device 150 will be described as an example, but the same applies to the second fixing device 170.

(11.1. Sequence when the power is turned on and when the front door is closed)
FIG. 6 is a flowchart from when the power switch is turned on until the standby mode is entered.

  When the power switch 101 is turned on by the operator, the CPU 301 is activated. The CPU 301 determines whether the first fixing device 150 is attached to the image forming apparatus 100 (S101). When the first fixing device 150 is attached, the CPU 301 can access the memory 154. If the first fixing device 150 is not attached, the process returns to S101. In this case, the CPU 301 may display a message for prompting the operation unit 180 to insert the first fixing device 150. If the first fixing device 150 is attached to the image forming apparatus 100, the process proceeds to S102.

  The CPU 301 causes the first fixing device 150 to perform the refresh sequence of FIG. 8 (S102). Details will be described later.

  In step S103, the CPU 301 waits until the image forming apparatus 100 is ready to start image formation. The CPU 301 causes each mechanism such as the first fixing device 150 and the image forming unit 309 to perform a preparation operation (startup) for starting image formation after the power switch 101 is turned on. For example, temperature control of the fixing roller 151 is one of them.

  When the start-up is completed and the image forming apparatus 100 is ready to start image formation (Yes in S103), the CPU 301 displays a message such as “Can print” on the operation unit 180 (S104). This notifies the operator that the image forming apparatus 100 can start image formation. And it shifts to standby mode.

  FIG. 7 is a flowchart from the state in which the front door is open to the standby mode.

  The open / close state of the front door 140 is detected by the CPU 301 based on a signal from the open / close sensor 305 of the front door 140. When the front door 140 is open, the CPU 301 waits for the front door 140 to be closed (S201). Further, when the front door 140 is open, the CPU 301 may display a message prompting the operation unit 180 to close the front door 140. When the CPU 301 detects that the front door 140 is closed (S201), the process proceeds to S202.

  S202 to S205 are the same as S101 to S104 in FIG. After S205, the process shifts to the standby mode.

(11.2. Refresh sequence)
FIG. 8 is a flowchart of the refresh sequence. The flowchart of FIG. 8 shows the details of the refresh sequence of S102, S203, and S409 described later.

  First, the CPU 301 reads data stored in the memory 154 of the first fixing device 150 mounted on the image forming apparatus 100 (S301). In the memory 154, for example, information indicating the number of conveyed sheets every 5 mm in the main scanning width direction of the recording material as shown in FIG. 10 is held.

  The CPU 301 stores a predetermined number of sheets (predetermined value) for the number of conveyed sheets (count value on the memory 154) of the recording material 102 of all main scanning lengths as information on the number of conveyed sheets for each main scanning length held in the memory 154. If the number is 500 or less in this example, the process proceeds to S303 (S302).

  The CPU 301 sets the value of the number of transported sheets for each main scanning length read from the memory 154 as the counter value on the RAM 302 for each main scanning length (S303).

  On the other hand, in S <b> 302, the CPU 301 determines that the value (count value) of the number of conveyed sheets of the recording material 102 of any main scanning length among the information on the number of conveyed sheets for each main scanning length held in the memory 154 is a predetermined value (this value). When the number exceeds 500 in the example, the process proceeds to S304.

  In S304, the CPU 301 executes the above-described fixing refresh operation. As a result, the surface of the fixing roller 151 is rubbed and the unevenness of the surface state is leveled.

  When the fixing refresh operation is completed, the CPU 301 sets the counter value to zero for each main scanning length. That is, the value on the RAM 302 is reset (S305).

  The CPU 301 records the number of conveyed sheets for every main scanning length as zero as information on the number of conveyed sheets held in the memory 154. (S306). Specifically, the values on the RAM 302 set in S305 are copied to the memory 154 in correspondence with the main scanning length information. By recording the number of transported sheets for all main scanning lengths as zero, the number of transported sheets of any main scanning length again exceeds a predetermined value (500 in this example) after execution of the fixing refresh operation. The CPU 301 can execute a fixing refresh operation. That is, the CPU 301 indicates that the fixing refresh operation has been executed in the memory 154 by recording the number of transported sheets for every main scanning length on the memory 154 as zero in association with the execution of the fixing refresh operation. Information is being recorded. In this way, the fixing refresh operation is repeatedly executed every time the number of conveyed recording materials 102 of any main scanning length exceeds the predetermined number.

  In addition, the number of pieces of information written to the memory 154 in S306 may be recorded when the CPU 301 detects the opening of the front door 140 based on a signal from the open / close sensor 305 in the standby mode. Good. Further, the information on the number of transported sheets in the memory 154 in S306 may be recorded as the power switch 101 is turned off. This is because the replacement of the first fixing device 150 involves opening the front door 140.

(11.3. Sequence for recording material count)
FIG. 9 is a flowchart regarding recording material counting. Specifically, a flowchart when executing a print job of the image forming apparatus 100 is shown.

  In the standby mode in which the image forming apparatus 100 can print, the apparatus waits until a print job is received from the external PC or the like via the operation unit 180 or the external I / F unit 304 (S401). At this time, the image forming apparatus 100 displays a selection screen for selecting the type of the recording material 102 to be printed on the display screen of the operation unit 180 or an external PC, and prints from the operator as the contents of the print job. An instruction of the type of the recording material 102 is also accepted.

  When the print job is received (S401 Yes), the CPU 301 controls each mechanism of the image forming apparatus 100 such as the stations 120 to 123, the first fixing device 150, the second fixing device 170, and the like. The formation process is started. That is, the print job is started (S402).

  When the CPU 301 detects that the recording material 102 has been transported to the first fixing device 150 at the stage where the print job is not completed (No in S403), the CPU 301 increments the count value on the RAM 302. Here, the CPU 301 counts the count value corresponding to the main scanning length of the conveyed recording material 102 among the count values on the RAM 302. In step S <b> 401, the CPU 301 acquires information on the main scanning length of the conveyed recording material 102 based on the content of the print job. Further, the CPU 301 detects that the recording material 102 has been conveyed to the first fixing device 150 based on a signal from the sensor 155.

  On the other hand, if it is not detected in S404 that the recording material 102 has been conveyed to the first fixing device 150, the CPU 301 proceeds to S406 without counting up. For example, even if the print job has not ended, the sensor 155 cannot detect the passage of the next recording material 102 after a certain period of time has passed since the previous recording material 102 was detected. is there. The timer 307 measures the fixed time.

  When the occurrence of a jam in the image forming apparatus 100 is not detected (No in S406), the CPU 301 continues the print job until the print job is completed while repeating the operations of S404 and S405.

  When the CPU 301 detects a jam in the image forming apparatus 100 (S406), the CPU 301 records the count value indicated by the RAM 302 in the memory 154 for each main scanning length as information on the number of transported sheets. (S407). Here, the CPU 301 detects a jam in the image forming apparatus 100 based on a signal from the sensor group 306. For example, if the sensor on the upstream side in the conveyance direction of the recording material 102 detects the passage of the recording material 102 and the downstream sensor does not detect the passage of the recording material 102 even after a predetermined time has passed, the CPU 301 It is determined that the recording material 102 stays between the two sensors. Here, the timer 307 measures the predetermined time.

  When a jam occurs in the image forming apparatus 100, the CPU 301 interrupts the print job. At this time, since the operator removes the recording material 102 staying in the conveyance path of the image forming apparatus 100, the front door 140 and the like are opened.

  The CPU 301 waits for the front door 140 to be closed (S408). When the CPU 301 detects that the front door 140 is closed based on a signal from the open / close sensor 305 (S408), it executes a refresh sequence (S409).

  The refresh sequence in S409 corresponds to the flow shown in FIG. In this refresh sequence, as described above, the memory 154 of the first fixing device 150 is read (S301). Here, the reason why the memory 154 is read is that the first fixing device 150 may be replaced at the timing when the front door 140 is opened for jam processing.

  In step S410, the CPU 301 waits until the image forming apparatus 100 is ready to start image formation. The CPU 301 causes each mechanism such as the first fixing device 150 and the image forming unit 309 of the image forming apparatus 100 to perform a preparatory operation (startup) for resuming image formation in accordance with the resolution of the jam. For example, temperature control of the fixing roller 151 is one of them.

  When the start-up is completed and the image forming apparatus 100 is ready to resume image formation (Yes in S410), the CPU 301 displays a message such as “printing can be resumed” on the operation unit 180 (S411). This notifies the operator that the image forming apparatus 100 can start image formation. After that, the process returns to S403, and the CPU 301 resumes the interrupted print job and continues the print job until the print job is completed.

  When the print job is finished (S403 Yes), the CPU 301 determines whether any of the values of the number of conveyed sheets for each main scanning length indicated by the RAM 302 exceeds a predetermined value (500 sheets in this example) ( S412).

  In S412, if the value of the number of transported sheets for every main scanning length indicated by the RAM 302 is equal to or less than a predetermined value (500 sheets in this example), the CPU 301 proceeds to S415.

  In S412, the CPU 301 executes the above-described fixing refresh operation when any of the values of the number of conveyed sheets for each main scanning length indicated by the RAM 302 exceeds a predetermined value (500 sheets in this example) (S413). . When the fixing refresh operation is completed, the CPU 301 sets the value for each main scanning length indicated by the RAM 302 to zero. That is, the counter value is reset (S414).

  In step S415, the CPU 301 records the count value indicated by the RAM 302 in the memory 154 for each main scanning length as information on the number of transported sheets. Here, when the flow of S414 is performed, the number of transported sheets for every main scanning length is recorded as zero as information on the number of transported sheets.

  The CPU 301 displays a message such as “Can print” on the operation unit 180 and notifies the operator that the image forming apparatus 100 can start image formation (S416). And it shifts to standby mode.

  By storing information on the number of conveyed sheets in the memory 154 before shifting to the standby mode, even when the first fixing device 150 is taken out from the image forming apparatus 100 during the standby mode, a more accurate number of conveyed sheets can be obtained. Information can be stored in the memory 154.

  The writing to the memory 154 in S407 may be executed only when the jam occurrence location in S406 is the first fixing device 150 and / or the second fixing device 170 (jamming in the fixing unit). Good. It is assumed that the front door 140 is opened by the operator after the jam occurs when a jam occurs in the fixing unit. In the case of a jam at the fixing unit, the operator removes the recording material 102 staying in the first fixing device 150 and / or the second fixing device 170. There is a possibility that the first fixing device 150 may be replaced by the operator when the front door 140 is opened.

  In this case, the sensors 153 and 155 function as a jam detection unit. For example, an optical sensor is used. The CPU 301 receives signals from the sensors 153 and 155 and detects that the recording material 102 is staying in the first fixing device 150 (jamming at the fixing unit). For example, when the downstream sensor 153 does not detect the passage of the recording material 102 even after a predetermined time has elapsed since the sensor 155 on the upstream side in the conveyance direction of the recording material 102 detects the passage of the recording material 102, the CPU 301 detects the sensor 155. , 153, it is determined that the recording material 102 remains. Here, the timer 307 measures the predetermined time.

  In the fixing refresh operation in S304 and S413, the time for which the refresh roller 156 performs the rubbing process may not be uniform. That is, the CPU 301 has a value of the number of conveyed sheets (count value) of the recording material 102 having the main scanning length out of the information of the number of conveyed sheets for each main scanning length, exceeding a predetermined value (500 sheets in this example). The rubbing process is executed for a time corresponding to the number of sheets.

  For example, in S412, S413, for a predetermined value of 500 sheets, if the count value is 500 sheets, the rubbing process for 30 seconds is performed. If the count value is 600 sheets, the rubbing process for 40 seconds is performed. Let it be executed.

  In this case, the rubbing processing time may be set to gradually increase as the amount of excess of the count value with respect to the predetermined value increases, or several step times may be set according to the amount of excess. May be. Data (table, function, etc.) for associating the amount of excess of the count value with respect to the predetermined value and the time of the rubbing process is stored in the ROM 303 in advance.

  As described above, the replacement of the first fixing device 150 by the operator involves opening and closing the front door 140 of the image forming apparatus 100. That is, when the front door 140 of the image forming apparatus 100 is opened by the operator, the first fixing device 150 may be replaced. Further, the first fixing device 150 may be replaced while the power switch 101 is off. For this reason, each time the power switch 101 of the image forming apparatus 100 is turned on or the front door 140 is closed, information is read from the memory 154 of the first fixing device 150 and conveyed to the memory 154. Get information about the number of copies. As a result, the CPU 301 can cause the first fixing device 150 to execute a fixing refresh operation based on more accurate information on the number of conveyed sheets, thereby suppressing deterioration in the image quality of the output recording material 102. Can do.

  In the above description, the first fixing device 150 has been described as an example, but the same applies to the second fixing device 170.

[Example 2]
In the first embodiment, when the count value of the number of transported recording materials 102 of any main scanning length exceeds a predetermined value during printing, the fixing refresh operation is executed after the print job is completed, and then the operation proceeds to the standby mode. To do.

  In the second embodiment, when the total count value (total count value) of the number of transported recording materials 102 of the main scanning length exceeds the predetermined value during printing, a fixing refresh operation is executed in the middle of the print job.

  In the first exemplary embodiment, the number of transported recording materials 102 having a main scanning length is counted on the RAM 302 and stored in the memory 154.

  In the second embodiment, the number of transported sheets is counted on the memory 154 of the first fixing device 150. That is, the CPU 301 updates the count value of the number of conveyed sheets on the memory 154 and records it every time it detects that the recording material 102 has been conveyed to the first fixing device 150 based on the signal of the sensor 155. It functions as a part (counter).

  The same applies to the second fixing device 170.

  Since other configurations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and detailed description thereof is omitted.

  Hereinafter, the first fixing device 150 will be described as an example. The same applies to the second fixing device 170.

  The memory 154 stores the number of recording materials 102 conveyed through the first fixing device 150 for each main scanning length of the recording material 102 of 5 mm. The CPU 301 causes the fixing refresh operation to be executed after the total number (total count value) of transported recording materials 102 for each main scanning length exceeds a predetermined value (500 sheets in this example). Thereafter, the count of the number of conveyed sheets for all main scanning lengths is set to zero. When the total count value again exceeds a predetermined value (500 sheets in this example), the CPU 301 executes a fixing refresh operation.

  Note that the value counted on the memory 154 is not the number of conveyed sheets for each main scanning length, but the number of all recording materials 102 conveyed to the first fixing device 150 regardless of the main scanning length. Also good.

  Further, the fixing refresh operation in the middle of the print job may be executed by interrupting the print job (that is, by increasing the interval of the recording material 102 conveyed to the first fixing device 150). It may be executed while continuing (that is, while performing the fixing process). However, it is preferable that the print job is interrupted (that is, the interval between the recording materials 102 conveyed to the first fixing device 150 is widened). In this case, it is possible to reduce a possibility that the toner image during the fixing process is disturbed due to vibration or the like when the refresh roller 156 is brought into contact with the fixing roller 151 in accordance with the fixing refresh operation.

(12. Control flow 2)
This will be described with reference to the flowcharts of FIGS. 6 and 7 and the flowcharts of FIGS. These flowcharts are performed when the CPU 301 functioning as an execution unit (recording unit) controls the operation of various mechanisms of the image forming apparatus 100 based on a control program stored in the ROM 303. The first fixing device 150 will be described as an example, but the same applies to the second fixing device 170.

(12.1. Sequence when the power is turned on and when the front door is closed)
The sequence when the power is turned on and when the front door is closed will be described with reference to the flowcharts of FIGS.

  In this embodiment, the process proceeds to the refresh sequence of FIG. 11 in S102 (FIG. 6) and S203 (FIG. 7).

  Since other configurations are the same as those of the first embodiment, description thereof is omitted.

(12.2. Refresh sequence)
FIG. 11 is a flowchart of the refresh sequence. The flowchart of FIG. 11 shows details of the refresh sequence of S102 (FIG. 6), S203 (FIG. 7), and S608 described later in the present embodiment.

  Since S501 is the same as S301 in FIG.

  In step S <b> 502, the CPU 301 sums up the values indicated by the information on the number of conveyed sheets held in the memory 154 for all main scanning lengths, and determines whether the value (total count value) exceeds a predetermined value.

  When the CPU 301 determines that the total count value is equal to or less than a predetermined value (500 sheets in this example), the CPU 301 proceeds to S503 (S502).

  Since S503 is the same as S304 in FIG.

  When the fixing refresh operation (S503) is completed, the CPU 301 sets the count value as zero for each main scanning length on the memory 154 as a counter value. That is, the value on the memory 154 is reset (S504).

  On the other hand, if the total count value is equal to or less than the predetermined value (500 sheets in this example) in S502, the CPU 301 ends the refresh sequence without executing the fixing refresh operation.

(12.3. Sequence for recording material count)
FIG. 12 is a flowchart regarding recording material counting. Specifically, a flowchart when executing a print job of the image forming apparatus 100 is shown.

  S601 and S602 are the same as S401 and S402 (FIG. 9), respectively, and thus description thereof is omitted.

  When the CPU 301 detects that the recording material 102 has been transported to the first fixing device 150 (S604 Yes) at a stage where the print job has not ended (S603 No), the CPU 301 increments the count value of the memory 154. Here, the CPU 301 counts up the count value corresponding to the main scanning length of the conveyed recording material 102 among the count values held by the memory 154. In step S601, the CPU 301 acquires information on the main scanning length of the conveyed recording material 102 based on the content of the print job. Further, the CPU 301 detects that the recording material 102 has been conveyed to the first fixing device 150 based on a signal from the sensor 155.

  On the other hand, if it is not detected in step S604 that the recording material 102 has been conveyed to the first fixing device 150, the CPU 301 proceeds to step S606 without counting up. For example, even if the print job has not ended, the sensor 155 cannot detect the passage of the next recording material 102 after a certain period of time has passed since the previous recording material 102 was detected. is there. The timer 307 measures the fixed time.

  If a jam occurs in the image forming apparatus 100 (S606 Yes), the CPU 301 interrupts the print job. At this time, since the operator removes the recording material 102 staying in the conveyance path of the image forming apparatus 100, the front door 140 and the like are opened.

  The CPU 301 waits for the front door 140 to be closed (S607). When the CPU 301 detects that the front door 140 is closed based on a signal from the open / close sensor 305 (S607), it executes a refresh sequence (S608).

  The refresh sequence in S608 corresponds to the flow shown in FIG. In this refresh sequence, as described above, the memory 154 of the first fixing device 150 is read (S501). Here, the reason why the memory 154 is read is that the first fixing device 150 may be replaced at the timing when the front door 140 is opened for jam processing.

  Since S609 is the same as S410, description thereof is omitted.

  When the start-up is completed and the image forming apparatus 100 is in a state where image formation can be resumed (S609 Yes), the CPU 301 displays a message such as “printing can be resumed” on the operation unit 180 (S610). This notifies the operator that the image forming apparatus 100 can start image formation (S610).

  After that, the process returns to S603, and the CPU 301 resumes the interrupted print job and continues the print job until the print job is completed.

  When the occurrence of a jam in the image forming apparatus 100 is not detected (No in S606), the CPU 301 indicates that the total (total count value) of the number of transported sheets for each main scanning length indicated by the memory 154 is a predetermined value (500 in this example). It is determined whether or not the number exceeds (sheets) (S611).

  In step S611, if the total count value indicated by the memory 154 is equal to or less than the predetermined value (500 sheets in this example), the CPU 301 proceeds to step S603 and continues the print job until printing is completed.

  In S611, when the total count value indicated by the memory 154 exceeds a predetermined value (500 sheets in this example), the CPU 301 causes the above-described fixing refresh operation to be executed (S612).

  When the fixing refresh operation is completed, the CPU 301 sets the value for each main scanning length indicated by the memory 154 to zero. That is, the counter value is reset (S613).

  Thereafter, the process returns to S603, and the CPU 301 continues the print job until the print job is completed.

  When the print job is finished (S603 Yes), the CPU 301 shifts to the standby mode.

  In this embodiment, the count value of the conveyance number of the recording material 102 is managed on the memory 154, and the CPU 301 records the count value of the conveyance number of the memory 154 each time the recording material 102 is conveyed to the first fixing device 150. To do. Thus, even when the first fixing device 150 is taken out from the image forming apparatus 100, more accurate information on the number of conveyed sheets can be held in the memory 154.

  As described above, the replacement of the first fixing device 150 by the operator involves opening and closing the front door 140 of the image forming apparatus 100. That is, when the front door 140 of the image forming apparatus 100 is opened by the operator, the first fixing device 150 may be replaced. Further, the first fixing device 150 may be replaced while the power switch 101 is off. Therefore, the information on the number of conveyed sheets is acquired from the memory 154 of the first fixing device 150 each time the power switch 101 of the image forming apparatus 100 is turned on or the front door 140 is closed. Then, the CPU 301 counts the number of transported sheets based on the count value of the number of transported sheets in the memory 154. As a result, the CPU 301 can cause the first fixing device 150 to execute a fixing refresh operation based on more accurate information on the number of conveyed sheets, thereby suppressing deterioration in the image quality of the output recording material 102. Can do.

  In the above description, the first fixing device 150 has been described as an example, but the same applies to the second fixing device 170.

[Modification 1]
Note that the image forming apparatus 100 may be configured to be set to a mode in which the above-described fixing refresh operation is not executed according to user settings. In this case, the operation unit 180 includes a selection unit for displaying a setting screen for setting either a mode in which the fixing refresh operation is executed or a mode in which the fixing refresh operation is not executed. The user can set whether or not to perform the fixing refresh operation through the operation unit 180. Information on the selected mode is held in the main body memory 312 as setting information of the image forming apparatus 100. An operation program in the case where the mode in which the fixing refresh operation is not executed is set is stored in the ROM 303. When the image forming apparatus 100 is set to a mode in which the fixing refresh operation is not executed, the CPU 301 executes a program that does not execute the above-described fixing refresh operation.

  As described above, the reason why the fixing refresh operation is necessary is that the uneven glossiness of the image generated due to the difference in surface roughness between the (I) non-passing portion, (II) passing portion, and (III) boundary region of the fixing roller 151. It is for suppressing. The difference in surface roughness of the fixing roller 151 appears as gloss unevenness when (I) the non-passing portion, (II) passing portion, and (III) the recording material 102 passes through the nip portion across the boundary region. is there. Therefore, gloss unevenness can also be suppressed by replacing and using a fixing device having the same configuration as the first fixing device 150 for each main scanning length of the recording material 102. Therefore, in a fixing device replacement system, a user who places importance on glossiness often prepares a fixing device for each main scanning length of the recording material 102 to be printed in order to avoid a reduction in the result article grade.

  As described above, when the influence of uneven gloss due to the edge portion of the recording material 102 can be ignored, the fixing refresh operation is not executed to prevent the rubbing scratch by the refresh roller 156 from affecting the glossiness of the image. Is desirable.

  As in this modification, the configuration of the image forming apparatus 100 can be switched between a mode in which the fixing refresh operation is executed and a mode in which the fixing refresh operation is not executed according to the user's selection, thereby meeting a wider range of user needs. An apparatus can be provided.

[Modification 2]
In the above description, the case where the end of the recording material 102 is in contact with the fixing roller 151 is described as an example of the cause of the difference in glossiness on the fixed image, but the present invention is not limited to this. For example, this is a case where a separation claw that contacts the fixing roller 151 is provided in order to prevent the recording material 102 from being wound around the fixing roller 151.

  In this case, as the fixing process is accumulated, contact scratches due to the contact of the separation claws may occur on the surface of the fixing roller 151. When the separation claw is arranged with a gap in the longitudinal direction (direction of the rotation axis) of the fixing roller 151, the surface of the fixing roller 151 becomes rough in the vicinity of the contact portion of the separation claw, and in the longitudinal direction of the fixing roller 151 There is a risk of non-uniform surface conditions. As a result, a difference in glossiness may occur on the fixed image.

  Even in such a case, by providing the refresh roller 156 and executing the fixing refresh operation as described above, the influence on the image quality due to the contact scratch can be reduced.

[Modification 3]
In the above description, the refresh roller 156 is provided on the fixing roller 151 and the surface of the fixing member is rubbed. However, the surface of the pressure belt 152 and the pressure roller 172 is provided with a rubbing rotator to be added. The surface of the pressure member may be rubbed.

[Modification 4]
In operation of the replacement system, the operator replaces and uses the fixing device according to the type and preference of the recording material 102 that he / she wants to print. At this time, if the operator does not use a fixing device that matches the recording material 102 to be printed, there is a possibility that a merit at the time of adopting the replacement system that a higher quality product can be obtained may not be obtained. Therefore, in this modification, the image forming apparatus 100 informs the operator whether or not the recording material 102 that the operator wants to print matches the use of the fixing device.

  In the following, a method for associating the use of the fixing device with the type of the recording material 102 to be printed will be described in a form supplementing the above-described FIGS. 8 and 9 (Example 1). Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted. The first fixing device 150 will be described as an example, but the same applies to the second fixing device 170.

  In the memory 154, as identification information indicating the use of the first fixing device 150, for example, identification information indicating the type and use of the fixing device such as “for envelope” is stored in advance. On the other hand, the main body memory 312 stores in advance information (limitation information) indicating the type of the recording material 102 that limits the fixing process in association with the identification information.

  In S301 of FIG. 8, the CPU 301 reads the data stored in the memory 154 of the first fixing device 150 attached to the image forming apparatus 100 and identifies the memory 154 of the first fixing device 150. Read information. Based on this identification information and the type of recording material 102 that limits the fixing process stored in the main body memory 312, the CPU 301 determines the type of recording material 102 that should limit the fixing process to the first fixing device 150. To grasp.

  In S401 of FIG. 9, the CPU 301 performs the fixing process in the first fixing device 150 on the selection screen for allowing the operator to select the type of the recording material 102 used for printing when receiving a print job from the operator. The type of the recording material 102 to be restricted is not selectable.

  As a result, printing by the first fixing device 150 that does not correspond to the recording material 102 that the operator wants to print can be restricted, and a higher quality product can be obtained.

  Information corresponding to the type of the recording material 102 that restricts the fixing process may be stored in the memory 154 of the first fixing device 150 instead of the main body memory 312. In this case, the CPU 301 reads information corresponding to the type of the recording material 102 that restricts the fixing process from the memory 154 of the first fixing device 150 in conjunction with the reading of the data from the memory 154 in S301 (S301). Based on the type of the recording material 102 that restricts the fixing process, the CPU 301 grasps the type of the recording material 102 that should restrict the fixing process to the first fixing device 150.

  Moreover, although this modification was demonstrated in the form supplemented to Example 1, you may apply to Example 2. FIG. Since the same applies to the second embodiment, the description thereof is omitted.

[Modification 5]
In the above description, the CPU 301 uses the information about the number of recording materials 102 conveyed to the first fixing device 150 and the second fixing device 170 as the memory 154 of the first fixing device 150 and the memory 174 of the second fixing device 170. It was set as the structure made to hold. The same information may be backed up not only in the memories 154 and 174 but also in the main body memory 312 in parallel with the writing of information into the memories 154 and 174 by the CPU 301.

[Modification 6]
In the above description, the operation unit 180 includes a display screen and a selection key. However, the operation screen of the operator may be received using the display screen as a touch panel and the screen of the touch panel as a selection unit.

[Modification 7]
Further, the image forming apparatus 100 including the first fixing device 150 and the second fixing device 170 has been described above as an example (tandem fixing). However, the image forming apparatus 100 may include only the first fixing device 150.

[Modification 8]
In the above description, the image forming apparatus 100 is described as an example of a color image forming apparatus having image forming units (stations 120 to 123) for forming yellow, magenta, cyan, and black toner images. It may be a forming device. For example, a monochrome image forming apparatus that forms a black toner image.

[Modification 9]
In the above description, the image forming apparatus 100 is configured to have the intermediate transfer belt 115 as an intermediate transfer member (intermediate transfer method), but may be configured as follows (direct transfer method).

  In this case, the image forming unit 309 includes an image forming unit (stations 120 to 123) and a transfer conveyance belt that functions as a transfer unit. The image forming units (stations 120 to 123) are provided so as to contact the transfer conveyance belt. The image forming apparatus 100 conveys the recording material 102 from the recording material storage unit 103 to the transfer conveyance belt. The transfer conveyance belt is a belt that conveys the recording material 102 while electrostatically adsorbing to the recording material 102, and includes a transfer roller at a position facing the image forming unit via the transfer conveyance belt (inner belt side). . The transfer roller transfers the toner image formed on the image carrier to the recording material 102 conveyed by the transfer conveyance belt. As a result, a toner image (unfixed) is formed on the recording material 102.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 102 Recording material 141 First mounting part 142 Second mounting part 150 First fixing device 151 Fixing roller 153 Sensor 154 Memory 155 Sensor 156 Refresh roller 170 Second fixing device 171 Fixing roller 173 Sensor 174 Memory 175 Sensor 180 Operation unit 301 CPU
309 Image forming unit

Claims (13)

An image forming apparatus for forming an image on a recording material,
An image forming unit for forming an unfixed toner image on a recording material;
A first rotating body that forms a nip portion for fixing an unfixed toner image formed on a recording material conveyed from the image forming unit, the fixing unit being detachable from a main body of the image forming apparatus And a fixing unit including a second rotating body,
A rubbing rotator for rubbing the surface of the first rotator,
A counting unit for counting the number of recording materials conveyed to the fixing unit;
A storage unit that is provided in the fixing unit and stores information on the number of sheets counted by the counting unit;
An execution unit that causes the rubbing rotary body to perform rubbing processing of the first rotating body when the number counted by the counting unit exceeds a predetermined number;
Have
The counting unit counts the number of recording materials conveyed to the fixing unit based on the information stored in the storage unit of the fixing unit mounted on the main body of the image forming apparatus. Forming equipment. A reception unit that receives an instruction of a width size that is a size of a recording material to be conveyed to the fixing unit and is a size in a direction perpendicular to the conveyance direction;
The counting unit counts the number of recording materials conveyed to the fixing unit based on the width size instruction acquired from the receiving unit for each width size,
The storage unit stores information on the number of sheets counted by the counting unit for each width size,
The execution unit causes the rubbing process to be executed when the number of recording materials of any of the width sizes out of the number of recording materials counted by the counting unit exceeds the predetermined number. The image forming apparatus according to claim 1.   The said execution part makes the said rubbing process be performed after completion | finish of the image formation process which forms an image on a recording material, when the number of sheets which the counting part counted exceeds the said predetermined number of sheets. The image forming apparatus according to any one of 1 and 2.   When the number of sheets counted by the counting unit exceeds a second predetermined number that is greater than the predetermined number at the end of the image forming process, the execution unit performs the time longer than the rubbing process. The image forming apparatus according to claim 3, wherein the rubbing rotary body is caused to perform a process of rubbing the surface of the first rotating body.   The said execution part records the information which shows that the said rubbing process was performed in the said memory | storage part according to having performed the said rubbing process, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. The image forming apparatus described in the item.   The execution unit causes the rubbing process to be executed when the number of recording materials conveyed to the fixing unit after the rubbing process exceeds the predetermined number. The image forming apparatus according to claim 5. A jam detection unit for detecting a jam at the fixing unit;
A recording unit that records information on the number of sheets counted by the counting unit in the storage unit in response to the detection of the jam by the jam detecting unit;
The image forming apparatus according to claim 1, further comprising:   The said execution part records the information of the number of sheets which the said counting part counted in the said memory | storage part when the image formation process which forms an image on a recording material was complete | finished. The image forming apparatus according to claim 1. A notification unit for notifying an operator that the image forming apparatus is in a state in which an image forming process for forming an image on a recording material can be performed;
When the number of pieces indicated by the information stored in the storage unit of the fixing unit attached to the main body of the image forming apparatus exceeds the predetermined number, the execution unit is not notified by the notification unit. 9. The image forming apparatus according to claim 1, wherein the rubbing process is performed on the image forming apparatus.   The rubbing rotator is characterized in that the surface of the first rotator is rubbed so that the ten-point average roughness of the first rotator is 0.5 μm or more and 2.0 μm or less. The image forming apparatus according to claim 1. An image forming apparatus for forming an image on a recording material,
An image forming unit for forming an unfixed toner image on a recording material;
A first rotating body that forms a nip portion for fixing an unfixed toner image formed on a recording material conveyed from the image forming unit, the fixing unit being detachable from a main body of the image forming apparatus And a fixing unit including a second rotating body,
A rubbing rotator for rubbing the surface of the first rotator,
A counting unit that counts a value corresponding to the length in the conveyance direction of the recording material conveyed to the fixing unit;
A storage unit that is provided in the fixing unit and stores information of a value counted by the counting unit;
When the value counted by the counting unit exceeds a predetermined value, an execution unit that causes the rubbing rotating body to perform rubbing processing of the first rotating body;
Have
The counting unit has a value corresponding to the length in the conveyance direction of the recording material conveyed to the fixing unit based on the information stored in the storage unit of the fixing unit mounted on the main body of the image forming apparatus. An image forming apparatus characterized by counting. An image forming apparatus for forming an image on a recording material,
An image forming unit for forming an unfixed toner image on a recording material;
A first rotating body that forms a nip portion for fixing an unfixed toner image formed on a recording material conveyed from the image forming unit, the fixing unit being detachable from a main body of the image forming apparatus And a fixing unit including a second rotating body,
A rubbing rotator for rubbing the surface of the first rotator,
A timing unit for measuring the time for the fixing unit to fix the recording material;
A storage unit that is provided in the fixing unit and stores information of a time measured by the timing unit;
When the time measured by the timer exceeds a predetermined time, an execution unit that causes the rubbing rotary body to perform rubbing processing of the first rotating body;
Have
The counting unit measures the time for the fixing unit to fix the recording material based on the time information stored in the storage unit of the fixing unit attached to the main body of the image forming apparatus. Image forming apparatus. A fixing device detachable from an image forming apparatus for forming an image on a recording material,
A first rotating body and a second rotating body that form a nip portion for fixing an unfixed toner image formed on a recording material;
A rubbing rotator for rubbing the surface of the first rotator,
A storage unit capable of storing information on the number of recording materials conveyed to the fixing device;
A fixing device.

Images