JP2015169938A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of shortening the change time of suitable fixing setting temperature when a kind of a recording material is changed.SOLUTION: When a paper thickness sensor 70 detects that a recording sheet S stored in a paper-feeding cassette 11 and the like is changed, a CPU 301 records a detection value to a preceding recording sheet S detected by the paper thickness sensor 70 and a flatness detector 80 in a memory portion 302, then successively detects kinds and the flatness of the following recording sheets S to store its detection value in the memory portion 302, decides the fixing setting temperature of a fixing device 60 to the following recording sheets S according to the detected kinds and the flatness, and resets the detection value stored in the memory portion 302 when the paper thickness sensor 70 detects the change of the recording sheet S.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a multifunction machine that combines these functions.

  An electrophotographic image forming apparatus such as a copying machine, a facsimile machine, a printer, or a multifunction machine that is a combination of these functions records a toner image transferred onto a recording material such as recording paper by heating and pressurizing it under predetermined conditions. An image is formed by fixing on a material.

  In such an image forming apparatus, it is necessary to consider fixing conditions such as a fixing set temperature and a pressurizing amount when fixing a toner image. In particular, when performing high-quality image formation, it is necessary to individually set conditions for fixing a toner image according to the type of recording material.

  This is because the image quality recorded on the recording material is greatly influenced by the material, thickness, humidity, smoothness, coating state, and the like of the recording material. For example, there is smoothness as an index representing smoothness. The smoothness is expressed in terms of time [seconds] in which a test plate is brought into close contact with the surface of the recording material and a certain amount of air flows between the surface of the recording material and the test plate. The term “coating” means that ink or paint is coated or printed.

  Here, there is a very high correlation between the smoothness of the recording material and the fixing quality. This is because the degree of unevenness on the surface of the recording material, particularly the fixing rate of the toner image in the recesses changes. Therefore, when fixing is performed under fixing conditions that do not consider smoothness, it is difficult to obtain a high-quality image, and it may cause abnormal images such as poor fixing depending on circumstances.

  On the other hand, with recent advances in image forming apparatuses and diversification of expression methods, there are hundreds of types of recording paper as recording materials, and the basis weight and thickness of each type of recording paper There are various brands due to the differences. Therefore, in order to form a high-quality image, it is necessary to set detailed fixing conditions and the like according to the type and brand of recording material such as recording paper.

  For example, there are other types of recording materials such as plain paper, gloss coated paper, matte coated paper, coated paper such as art coated paper, OHP sheets, etc., as well as special paper with the paper surface embossed. doing. These special papers are increasing in recent years. Note that recording materials other than recording paper and the like exist as recording materials.

By the way, in the current image forming apparatus, as one of the fixing conditions, it is very common to indicate the thickness of the recording material as the basis weight per unit area and set it according to the basis weight. For example, recording paper with a basis weight of 60 to 90 g / m ² is plain paper, recording paper with 91 to 105 g / m ² is medium thick paper, recording paper with 106 to 200 g / m ² is thick paper, and so on, depending on the basis weight. Classification is performed, and the fixing temperature, recording material conveyance speed (fixing speed), and the like are changed for each classification.

  In general, the basis weight information of the recording material is often described in a package or the like in which the recording material is packed in units of a predetermined number of sheets, and can be grasped by the user himself.

  For example, in the case of a copying machine, such basis weight information can be recognized by the control unit of the apparatus main body by setting it using an operation unit (operation panel). In the case of a printer, it can be recognized by the control unit of the apparatus main body by setting it using a printer driver displayed on the display of a personal computer and including it in the print information. Furthermore, a technique relating to an image forming apparatus that is equipped with a sensor that detects the thickness of a recording material and that automatically detects the thickness of the recording material and recognizes it by a control unit of the apparatus main body has been studied.

  On the other hand, the smoothness of the recording material is usually not printed on the package of the recording material, and it is extremely difficult for the user to know the smoothness information. For this reason, the smoothness of the recording material has to be obtained using a sensor or the like.

  As described above, there is a high correlation between smoothness and fixing quality, but smoothness is the time during which a certain amount of air flows between the surface of the recording material and the test piece. Have difficulty. Therefore, conventionally, as a substitute characteristic of smoothness, a sensor that measures surface roughness and light reflected light quantity highly correlated with smoothness has been studied.

  Conventionally, as a method for detecting such smoothness, illumination light emitted from a light source such as a light emitting diode (LED) is irradiated onto the surface of the recording material, and the smoothness of the recording material is determined by the amount of reflected light reflected from the surface of the recording material. A light detection method for detecting is known. According to this light detection method, since the smoothness can be detected without contact with the recording material, there is an advantage that there is no damage to the recording material.

  Further, as a smoothness detection method using this type of light detection method, for example, the material (smoothness) of the recording material is determined based on the amount of reflected light reflected on the surface of the recording material and the amount of transmitted light transmitted through the recording material. A detection method is known (for example, see Patent Document 1).

  In addition, it has one light emitting source and two light receiving portions, and the two light receiving portions receive the regular reflection light and the scattered reflected light of the illumination light irradiated on the surface of the recording material from the one light emission source. A method of detecting the material (smoothness) of the recording material based on the amount of light is also known (see, for example, Patent Document 2).

  The smoothness detected by such a detection method is used, for example, for setting fixing conditions such as fixing temperature and image forming conditions. Further, a predetermined time is required from the start of image formation to transfer onto transfer paper and until the actual fixing temperature reaches the fixing set temperature.

  Therefore, in an image forming apparatus that uses the detected smoothness of the recording material for setting the fixing conditions and the image forming conditions, it is necessary to detect the smoothness in advance in consideration of the predetermined time as described above. In particular, the arrangement and detection timing of the sensor for detecting the smoothness are particularly important.

  Therefore, using the sensor for detecting the smoothness, the sensor detection value for the recording material conveyed first and the sensor detection value for the recording material conveyed next to the recording material are used for subsequent conveyance. An image forming apparatus that determines the fixing set temperature for the recording material has been proposed previously.

  However, in this method, when the fluctuation width of the smoothness of the recording material is large between the front and rear recording materials, the change range of the fixing temperature is also largely switched, the temperature control is not stable, and as a result, an abnormal image is likely to occur. In addition, there is a problem that the power consumption increases.

  Therefore, an image forming apparatus has been proposed in which the representative smoothness is calculated using the average smoothness and standard deviation of a plurality of recording materials, and the fixing temperature is changed based on the calculation result.

  Thereby, there is little change of control temperature, it became possible to suppress the temperature ripple which generate | occur | produces by control temperature change, and it became possible to make control temperature low. Even if the correction amount varies due to variations in the recording material, the average value and the standard deviation are used to carry the next offset without risking the occurrence of offset. The correction amount of the fixing set temperature for the recording material to be recorded could be minimized.

  However, in this method, since the representative smoothness is calculated using the average smoothness calculated from the past sensor detection values and the standard deviation, when the type of recording material to be used is changed, it is appropriate for different types. There is a problem that it is difficult to change to a fixed fixing temperature.

  The present invention has been made in view of the circumstances as described above, and provides an image forming apparatus that can contribute to shortening the change time of an appropriate fixing set temperature when the type of recording material is changed. The purpose is to do.

  In order to achieve the above object, an image forming apparatus according to the present invention includes a storage unit that stores and feeds a recording material, a type detection unit that detects the type of the recording material stored in the storage unit, and a recording material Smoothness detecting means for detecting the smoothness on the surface, and the detected value for the previous recording material detected by the type detecting means and the smoothness detecting means are stored, and detected by the type detecting means and the smoothness detecting means. Based on the detected values recorded in the storage means, the storage means for sequentially accumulating and storing the detected values for the recording material after the recording, the fixing means for fixing the toner image transferred to the surface of the recording material by heating and pressing And a temperature control means for determining a fixing set temperature of the fixing means for the subsequent recording material, the temperature control means when the detected value of the recording material detected by the type detecting means deviates from a predetermined value. It has a configuration to reset the detected value stored in the storage means as the type of the recording material is changed.

  According to the present invention, it is possible to provide an image forming apparatus that can contribute to shortening the change time of an appropriate fixing set temperature when the type of recording material is changed.

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. 1 shows an image forming apparatus according to an embodiment of the present invention, where (A) is an explanatory diagram of a drawer sensor ON (light incident) state, and (B) is an explanatory diagram of a drawer sensor OFF (light shielding) state. 1 illustrates an image forming apparatus according to an embodiment of the present invention, where (A) is an explanatory diagram of a sheet set detection sensor ON (light incident) state, and (B) is an explanatory diagram of a sheet set detection sensor OFF (light shielding) state. . 1A and 1B show an image forming apparatus according to an embodiment of the present invention, where FIG. 3A is an explanatory diagram of a storage sensor ON state, and FIG. It is a schematic front view of the smoothness detector which concerns on embodiment of this invention. 1 is a functional block diagram of an image forming apparatus according to an embodiment of the present invention. It is a graph which shows the relationship between the representative smoothness and correction temperature which concern on embodiment of this invention. It is a graph which shows the area coverage rate relationship between normal distribution and standard deviation which concerns on embodiment of this invention. It is a graph which shows an example of the change with respect to the number of passing sheets of the number of passing sheets and a standard deviation which concerns on embodiment of this invention. It is a graph for comparing the change in the correction temperature for each conventional sheet passing number and the change in the correction temperature for each sheet passing number according to the present invention. FIG. 7 is a flowchart showing a fixing temperature correction routine in the fixing device according to the embodiment of the present invention.

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

  As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment employs an electrophotographic system, and from the top in the drawing, a document sheet conveying apparatus 100, an image reading apparatus 200, an image forming apparatus main body 300, and the like. A double-sided conveying device 400 disposed on the side surface of the image forming apparatus main body 300.

  The document sheet conveying apparatus 100 uses an automatic document sheet conveying apparatus that automatically loads and conveys a single sheet of document sheets in order from the topmost document sheet, and can be installed as an option.

  The document sheet conveying apparatus 100 can be opened and closed with respect to the image reading apparatus 200 with the back side of the image forming apparatus 1 as an axis. The document sheet conveying apparatus 100 may employ a known configuration. Therefore, detailed description thereof is omitted here.

  The image reading device 200 is a scanner device, and has a function of reading an image of a document sheet in the process of being conveyed by the document sheet conveying device 100 and a function of reading an image of a fixed document (not shown). The image data of the original sheet read by the image reading apparatus 200 is output to the image forming apparatus main body 300. The image reading apparatus 200 can employ a known configuration. Therefore, detailed description thereof is omitted here.

  The image forming apparatus main body 300 includes a paper feeding device 10, an exposure device 20, an image forming device 30, an intermediate transfer device 40, a secondary transfer device 50, and a fixing device 60 in the order of the image forming process.

  The sheet feeding device 10 is disposed below the inside of the image forming apparatus main body 300. The paper feeding device 10 has a plurality of drawer-type paper feeding cassettes 11 arranged in a plurality of stages. In this example, the upper and lower two-stage paper feeding cassettes 11A and 11B are arranged as the paper feeding cassette 11. The paper feed cassette 11 can store a recording sheet S such as a recording sheet as a recording material. The recording sheets S stored in the paper feed cassettes 11A and 11B are fed one by one from the uppermost one and fed to the transport path unit 12 at the upper part on the downstream end side of the paper feed cassettes 11A and 11B. Feed rollers 13A and 13B are provided. The paper feed cassettes 11A and 11B are, for example, a drawer sensor arranged on the back side (the depth side of the paper surface in FIG. 1) or the side surface in the drawing direction as to whether the paper cassettes 11A and 11B have been drawn out or properly stored in the image forming apparatus main body 300. 111 and 112 are detected.

  FIG. 2 shows an example of the drawer sensors 111 and 112, and includes detection units 111 a and 112 a and movable units 111 b and 112 b that are displaced in conjunction with the drawing / inserting operation of the paper feeding cassettes 11 A and 11 B. For the detection units 111a and 112a, photoelectric sensors or the like are used. For example, as shown in FIG. 2 (A), the detection unit 111a is turned on when the light is incident to detect a drawing state in which the paper feed cassette 11A is pulled out, and as shown in FIG. 2 (B), the detection unit 111a When the light is shielded, it is turned off to detect the storage state in which the paper feed cassette 11A is inserted.

  Sheet set detection sensors 121 and 122 are provided in the vicinity of the sheet feeding rollers 13A and 13B. The sheet set detection sensors 121 and 122 set the recording sheet S when the paper feeding cassettes 11A and 11B are pulled out and the recording material is exchanged, and the paper feeding cassettes 11A and 11B are inserted into the storage state. Detect state. As shown in FIG. 3, the sheet set detection sensor 121 includes a detection unit 121 a such as a photoelectric sensor and a movable unit 121 b that is displaced in conjunction with the raising and lowering operations of the tray bottoms 11 a and 11 b of the paper feed cassettes 11 </ b> A and 11 </ b> B. I have. For example, as shown in FIG. 3A, the detection unit 121a is turned on when the detection unit 121a enters the light until just before the insertion of the paper feed cassette 11A, and detects a sheet non-detection state. Further, for example, as shown in FIG. 3B, the detection unit 121a is turned off when the insertion completion detection unit 121a of the paper feed cassette 11A is shielded and enters a sheet detection state.

  As shown in FIG. 3B, the tray bottoms 11a and 11b are tilted according to the number of stored recording sheets S when the paper cassettes 11A and 11B are not pulled out from the image forming apparatus main body 300. It is in. On the other hand, when the recording sheet S is pulled out from the image forming apparatus main body 300 and the recording sheet S is replenished or replaced, as shown in FIG. In position. When the paper cassettes 11A and 11B are inserted from this state, the tray bottoms 11a and 11b are displaced so as to incline from the initial position to the paper feeding position by an elevating mechanism (not shown) such as a motor or a solenoid immediately before starting the paper feeding. To do.

  When the tray bottoms 11a and 11b are inclined from the initial position to the paper feeding position, the paper feeding rollers 13A and 13B come into contact with the uppermost recording sheet S, and the movable portion 121b is connected to the paper feeding rollers 13A and 13B. It rotates integrally and shields the movable part 121b.

  The conveyance path unit 12 includes a conveyance roller pair 14, a registration device 15, a secondary transfer device 50, a fixing device 60, a paper discharge unit 16, a discharge unit 16 on the downstream side in the conveyance direction of the recording sheet S from the uppermost paper supply roller 13 </ b> A. The paper tray unit 17 is arranged in order.

  The registration device 15 corrects the skew of the recording sheet S conveyed to the conveyance path unit 12 and adjusts the secondary transfer timing, and then conveys the recording sheet S to the downstream side.

  The exposure device 20 is disposed above the uppermost sheet cassette 11A. The exposure device 20 irradiates the image forming device 30 with laser light based on image data of a document sheet or fixed document received by the image reading device 200 or image data received through a personal computer or a telephone line (not shown).

  The image forming device 30 includes image forming devices 30c, 30m, 30y, and 30k for each color of cyan (c), magenta (m), yellow (y), and black (k). The image forming devices 30c, 30m, 30y, and 30k are arranged in a quadruple tandem manner. The image forming devices 30c, 30m, 30y, and 30k are charged, developed, transferred (primary transfer), cleaned, and discharged on the periphery of a drum-shaped image carrier 31 that rotates clockwise in FIG. Processes are executed in this order. The image forming devices 30c, 30m, 30y, and 30k replenish toner, which is a developer corresponding to each color, from the toner bottles 32c, 32m, 32y, and 32k.

  The intermediate transfer device 40 is configured to stretch an endless intermediate transfer belt 41 wound around a plurality of rollers substantially horizontally and to rotate counterclockwise in the drawing. The intermediate transfer device 40 includes primary transfer devices 42c, 42m, 42y, and 42k that face each other with the image carrier 31 of the image forming devices 30c, 30m, 30y, and 30k and the intermediate transfer belt 41 interposed therebetween. The primary transfer devices 42c, 42m, 42y, and 42k are configured to transfer the toner image formed on the image carrier 31 to the intermediate transfer belt 41.

  The secondary transfer device 50 is arranged on the path of the conveyance path unit 12 and secondarily transfers a toner image, which is a primary transfer image formed on the intermediate transfer belt 41, to the recording sheet S.

  The fixing device 60 includes a heating unit 61 disposed on the sheet surface side for fixing the toner image transferred to the recording sheet S to the recording sheet S, and a pressurizing unit disposed on the sheet back surface side to pressurize the heating unit 61. 62. The fixing device 60 in the present embodiment constitutes a fixing unit.

  The fixing device 60 fixes the toner image on the recording sheet S by heating and pressurizing the recording sheet S on which the toner image is secondarily transferred. The image forming apparatus main body 300 discharges the recording sheet S after toner fixing from the paper discharge unit 16 to the paper discharge tray unit 17.

  The double-sided conveyance device 400 is used when images are formed on both sides of the recording sheet S, and includes a switchback unit 410 and a reversing unit 420. In addition to the paper feeding cassette 11, the duplex conveying device 400 includes a manual paper feeding device 430 that stores the recording sheet S and can supply the recording sheet S to the image forming apparatus main body 300.

  The recording sheet S on which the image is fixed on one side is conveyed to the reversing unit 420 in a state where the upstream end and the downstream end in the conveying direction are switched by the switchback unit 410. The reversing unit 420 re-feeds the recording sheet S to the vicinity of the upstream end of the transport path unit 12 using a path for supplying the recording sheet S from the manual sheet feeding device 430 to the image forming apparatus main body 300.

  The manual sheet feeding device 430 is pivotally supported by the double-sided conveyance device 400 at the lower end side so as to be rotatable. As shown in FIG. 4A, the manual sheet feeding device 430 is stored in the double-sided conveyance device 400 and from the double-sided conveyance device 400 with the leading end side obliquely upward as shown in FIG. It is designed to rotate to the protruding usage state.

  The double-sided conveyance device 400 is provided with a storage sensor 401 that detects that the manual sheet feeding device 430 is in the storage state. For example, a button switch, a photoelectric sensor, or the like is used for the storage sensor 401. The storage sensor 401 is turned on when the manual sheet feeding device 430 is in the storage state, and is turned off when it is in use.

  In addition, the manual sheet feeder 430 is provided with an empty sensor 431. As the empty sensor 431, for example, a photoelectric sensor is used. For example, the empty sensor 431 is turned on when the recording sheet S is stored in the manual sheet feeder 430 to detect the storage of the recording sheet S, and the recording sheet S is stored in the manual sheet feeder 430. It turns off when there is no incident light and detects that the recording sheet S is empty. When the manual sheet feeding device 430 is stored in the duplex conveying device 400, the recording sheet S is not stored in the manual sheet feeding device 430. Therefore, the empty sensor 431 detects whether or not the recording sheet S is stored in the manual sheet feeding device 430 when the storage sensor 401 detects the non-storage state, that is, the use state.

  On the other hand, between the conveying roller pair 14 and the registration device 15, a paper thickness sensor 70 that detects the type from the paper thickness of the recording sheet S is provided upstream, and a smoothness detector that detects the surface smoothness of the recording sheet S. 80 is arranged on the downstream side.

  The paper thickness sensor 70 includes, for example, a light emitting unit 71 and a light receiving unit 72. The paper thickness sensor 70 detects the paper thickness of the recording sheet S based on the amount of light received by the light receiving unit 72 when the recording sheet S conveyed to the conveyance path unit 12 passes between the light emitting unit 71 and the light receiving unit 72. Thus, the type of the recording sheet S is determined.

Receiving unit 72, for example, the type of the recording sheet S, depending on the amount of light received by the light receiving portion 72, the basis weight 60 to 90 g / ^{m 2} plain paper, thick paper in the 91~105g / ^{m 2,} 106~200g / Sort like m ² cardboard.

In addition, the thing with the high sensitivity of the light-receiving part 72 can be used. Thus, for example, basis weight 60~81g / ^{m 2} plain paper, recycled paper, midweight port basis weight 82~105g / ^{m 2,} cardboard 1 having a basis weight of 106~169g / ^{m 2,} the basis weight 170~220g / ^{m 2} cardboard 2 basis weight 221～256G / ^{m 2} cardboard 3, it is also possible to subclassification of as. At this time, for example, the middle thick mouth may include special paper, letterhead-attached paper, coated paper, envelope, and the like.

  The smoothness detector 80 is provided on the upstream side of the registration device 15 and calculates the smoothness of the recording sheet S fed to the transport path unit 12 from the paper feed cassette 11 or the manual paper feed device 430. The smoothness detector 80 detects the smoothness of the recording sheet S used when setting the fixing conditions including the fixing set temperature described later, from the calculated smoothness of the recording sheet S. The smoothness detector 80 in the present embodiment constitutes a smoothness detection means.

  The smoothness detector 80 is arranged on the upstream side of the registration device 15, so that it is not installed so as to correspond to each of the paper feed cassettes 11 </ b> A and 11 </ b> B and the manual paper feed device 430, and the transport path unit 12. It is possible to calculate the smoothness of all the recording sheets S passing through.

  In addition, by disposing the paper thickness sensor 70 and the smoothness detector 80 on the upstream side of the registration device 15, when the registration processing of the recording sheet S is performed, that is, the conveyance of the recording sheet S is instantaneously stopped. Paper thickness and smoothness can be detected. Therefore, the strictness and reliability of the detection value can be made higher than when the paper thickness and smoothness are detected in the paper feeding process, that is, in a moving state.

  FIG. 5 is an explanatory diagram of an example of the configuration of the smoothness detector 80.

  The smoothness detector 80 includes a light source 81, a collimating lens 82, a regular reflection light detector 83 as a light detector, an aperture 84, and a control unit 85.

  The light source 81 is configured by a surface emitting laser (VCSEL: Vertical Cavity Surface Emitting Laser). Therefore, the light source 81 can suppress FFP (Far Field Pattern) and form a more accurate optical system than a case where a general LED or an end face LD (Laser Diode) is used as a stable light source. Can do. Here, FFP is a value that means the beam divergence angle. The light source 81 is not limited to the surface emitting laser, and may be configured by various light sources such as LEDs.

  The collimating lens 82 is an aspherical convex lens that is provided between the light source 81 and the irradiation surface of the recording sheet S and converts a laser beam emitted from the light source 81 into a collimated beam. Here, collimating means that the laser beam emitted from the light source 81 is converted into a parallel beam that does not diffuse and converge. Therefore, the collimated light beam means a laser light beam adjusted in a parallel state.

  The smoothness detector 80 increases the detection sensitivity of the smoothness of the recording sheet S by adjusting the incident angle of the laser beam irradiated from the light source 81 by the collimating lens 82 and the parallelism of the collimated beam. Can be made.

  The regular reflection light detector 83 is provided on the downstream side of the reflection surface of the recording sheet S in the optical axis direction of the laser light beam emitted from the light source 81, and detects the reflected light beam that is regularly reflected by the recording sheet S. It consists of a photodiode or the like.

  The regular reflection light detector 83 detects the light intensity of the reflected light flux regularly reflected on the recording sheet S as a voltage, and outputs the detection result to the control unit 85 as an output signal. Thereby, the smoothness detector 80 can calculate the smoothness of the recording sheet S by the control unit 85.

  The aperture (aperture stop) 84 is provided between the irradiation surface of the recording sheet S and the regular reflection light detector 83, and restricts the incident angle of the reflected light beam incident on the regular reflection light detector 83. By providing the aperture 84, the smoothness detector 80 can limit the scattered light mixed in the reflected light beam while ensuring the amount of the reflected light beam irradiated from the light source 81 and reflected by the surface of the recording sheet S. Therefore, it is possible to prevent the accuracy of smoothness detection from being lowered.

  The control unit 85 is connected to the regular reflection light detector 83 and calculates the smoothness of the recording sheet S from the sensor value (detection value) detected by the regular reflection light detector 83. The function of the control unit 85 will be described later.

  The smoothness detector 80 configured as described above detects the light intensity of the specularly reflected light in the specular direction of the laser beam irradiated to the recording sheet S by the light source 81 to thereby smooth the surface of the recording sheet S. Is supposed to be detected. The smoothness detector 80 in the present embodiment constitutes a smoothness detection means.

  Next, an example of the image forming processing operation in the image forming apparatus 1 will be described in the case of the copy function.

  First, the image forming apparatus 1 supports the image forming apparatuses 30c, 30m, 30y, and 30k in which the latent images corresponding to the color toner images of the original image read by the image reading apparatus 200 are uniformly charged by the charging device. Writing is performed on the surface of the body 31 using the exposure apparatus 20.

  Next, the image forming apparatus 1 forms a toner image by applying each color toner from the developing device to each color toner latent image on the image carrier 31 of each image forming device 30c, 30m, 30y, 30k.

  Next, the image forming apparatus 1 sequentially transfers the respective color toner images formed on the image carrier onto the intermediate transfer belt 41 using the primary transfer apparatuses 42c, 42m, 42y, and 42k, thereby performing intermediate transfer. A desired color image is formed on the belt 41.

  On the other hand, the image forming apparatus 1 selectively rotates one of the sheet feeding rollers 13A and 13B in the two-stage sheet feeding cassettes 11A and 11B to feed out the recording sheet S from the corresponding sheet feeding cassette 11 or manually. The manually fed recording sheet S is fed out from the difference sheet feeding device 430.

  Next, the image forming apparatus 1 carries the recording sheet S fed from the paper feed cassette 11 or the manual paper feed device 430 into the transport path unit 12.

  Next, the image forming apparatus 1 uses the registration device 15 to record the recording sheet S conveyed to the registration device 15 through the conveyance path unit 12 and timing with the toner image formed on the intermediate transfer belt 41. 50 is fed to the secondary transfer position.

  Here, the image forming apparatus 1 calculates the smoothness of the recording sheet S by the smoothness detector 80 and then transfers the color image on the intermediate transfer belt 41 to the recording sheet S by the secondary transfer device 50.

  Next, the image forming apparatus 1 conveys the recording sheet S on which the color image has been transferred to the fixing device 60, and heats and presses the recording sheet S at the nip portion of the fixing device 60, thereby fixing the color image on the recording sheet S.

  Here, when an image is also formed on the back side of the recording sheet S, the image forming apparatus 1 uses a switching claw (not shown) for switching the conveyance path of the recording sheet S on which the color image is fixed on one side. Transport to the transport device 400.

  Then, in the double-sided conveyance device 400, the recording sheet S is conveyed to the reversing unit 420 in a state where the upstream end and the downstream end in the conveying direction are switched by the switchback unit 410. The reversing unit 420 re-feeds the recording sheet S to the vicinity of the upstream end of the transport path unit 12 using a path for supplying the recording sheet S from the manual sheet feeding device 430 to the image forming apparatus main body 300.

  After the recording sheet S is fed again, the image forming apparatus 1 secondarily transfers the color image for the back surface formed on the intermediate transfer belt 41 to the recording sheet S in the same manner as the front surface, and the fixing device 60. To fix the color image that has been secondarily transferred.

  When all the fixing of the color image on the recording sheet S is completed, the image forming apparatus 1 discharges the recording sheet S on which the color image is fixed from the paper discharge unit 16 toward the paper discharge tray unit 17. Are stacked, the image forming operation is completed.

  FIG. 6 is a functional block diagram showing each configuration of the image forming apparatus 1.

  In FIG. 6, the image forming apparatus 1 is configured such that each element is connected to a CPU 301 provided in the image forming apparatus main body 300 via a bus, and the CPU 301 controls each element so that the function of the image forming apparatus 1 can be exhibited. Yes.

  The CPU 301 is connected to the document sheet conveying apparatus 100, the image reading apparatus 200, and the double-sided conveying apparatus 400, and controls these drive systems or control systems. Further, the CPU 301 is connected to a paper feed cassette 11, a transport path unit 12, a paper discharge unit 16, and a manual paper feed device 430. These drive systems (for example, the paper feed cassettes 11A and 11B) are connected. The paper feed rollers 13A and 13B) are controlled. In addition to the exposure device 20, the image forming device 30, the intermediate transfer device 40, the secondary transfer device 50, the registration device 15, the conveyance roller pair 14 (not shown in FIG. 6), the CPU 301 and the paper thickness of the fixing device 60. A sensor 70 and a smoothness detector 80 are connected. Further, a memory unit 302, a current control circuit 305, an A / D conversion unit 306, a voltage detection unit 307, and an interface 308 are connected to the CPU 301.

  The CPU 301 includes a drawer sensor 111 that detects the drawer state of the paper feed cassette 11A, a sheet set detection sensor 121 that detects the set state of the recording sheet S, and an empty sensor 131 that detects whether the recording sheet S is empty. The detection signal is input.

  The CPU 301 includes a drawer sensor 112 that detects a drawing state of the sheet cassette 11B, a sheet set detection sensor 122 that detects a setting state of the recording sheet S, and an empty sensor 132 that detects whether the recording sheet S is empty. The detection signal is input.

  The CPU 301 receives a detection signal from the storage sensor 401 that detects the storage state of the manual sheet feeding device 430 with respect to the duplex conveying device 400. In addition, regarding the manual sheet feeding device 430, a detection signal is input from an empty sensor 431 that detects whether the recording sheet S is empty.

  Accordingly, the CPU 301 detects that the drawer sensors 111 and 112 have pulled out the sheet cassettes 11A and 11B, and the recording sheet S when the storage sensor 401 detects a change in the storage state of the manual sheet feeder 430. It is detected that the storage state has changed. Similarly, the CPU 301 detects that the storage state of the recording sheet S has been changed by the sheet set detection sensors 121 and 122 according to the detection result of the recording sheet S setting state. Further, the CPU 301 detects that the storage state of the recording sheet S has changed when the empty sensors 131, 132, 431 detect that the recording sheet S is empty. The drawer sensors 111 and 112, the storage sensor 401, the sheet set detection sensors 121 and 122, and the empty sensors 131, 132, and 431 also serve as a type detection unit that detects that the type of the recording sheet S has been changed. .

  Further, when the detected value of the recording sheet S by the paper thickness sensor 70 is different from the detected value for the previous recording sheet S, the CPU 301 has changed the type of the recording sheet S to a different type of recording sheet S from the previous time. Is detected. Further, when the paper type information of the recording sheet S included in the print data received from the external communication device 310 is different from the previous time, the CPU 301 confirms that the type of the recording sheet S has been changed to a different type of recording sheet S from the previous time. To detect. Similarly, when the type of the recording sheet S designated by the operation unit 320 is different from the previous time, the CPU 301 detects that the type of the recording sheet S has been changed to a different type of recording sheet S from the previous time. The paper thickness sensor 70, the external communication device 310, and the operation unit 320 function as a type detection unit that detects that the type of the recording sheet S has been changed.

  Note that the upper sheet cassette 11A, the lower sheet cassette 11B, and the manual sheet feeder 430 constitute a storage unit that stores the recording sheet S. In addition, the empty sensors 131, 132, 431 and the pull-out sensors 111, 112 can be used in combination as type detecting means for detecting that the type of the recording sheet S has been changed.

  The fixing device 60 includes a heat source control circuit 63 that determines the amount of heat supplied to the heat source 64 of the heating unit 61 (hereinafter referred to as “supplied heat amount”), that is, a fixing set temperature, and a thermistor that detects the temperature of the heat source 64 of the heating unit 61. 66.

  Here, in order to obtain a high-quality image as described above, it is necessary to determine the fixing set temperature in consideration of the type and smoothness of the recording sheet S that has a very high correlation with the fixing quality. Therefore, the heat source control circuit 63 according to the present embodiment determines the fixing set temperature according to the sensor values of the paper thickness sensor 70 and the smoothness detector 80 described above.

  For example, when the type information of the recording sheet S including the paper thickness is input by the operation unit 320 provided in the image forming apparatus main body 300 or the external communication device 310 such as a personal computer, the CPU 301 detects the sensor of the paper thickness sensor 70. The paper type information is used in preference to the value.

  In addition, the fixing device 60 includes an A / D conversion unit 65 that A / D converts the analog value detected by the thermistor 66 into a digital value for processing by the CPU 301 and notifies the CPU 301 of it. Further, the fixing device 60 includes a pressure control circuit 67 that controls the force pressing the pressure unit 62 against the heating unit 61 and the width of the nip portion.

  Further, the control unit 85 of the smoothness detector 80 is connected to the fixing device 60, and when the fixing device 60 receives a signal transmitted from the control unit 85, the heat source control circuit 63 and the pressure control circuit. 67 is executed. Thereby, the control part 85 in this Embodiment comprises a temperature control means.

  The memory unit 302 includes a ROM 303 and a RAM 304. The ROM 303 stores program codes executed by the CPU 301 and a fixing control pattern. In addition, the detection voltage is temporarily stored in the RAM 304.

  The CPU 301 reads the program code stored in the ROM 303, develops it in the RAM 304, executes the program defined by the program code while using the RAM 304 as a data buffer, and controls each element.

  The current control circuit 305 receives signals transmitted from the paper thickness sensor 70 and the control unit 85 of the smoothness detector 80, and determines a transfer current value when the secondary transfer device 50 transfers the toner image to the recording sheet S. It is an element to control.

  For example, when the type information of the recording sheet S including the paper thickness is input by the operation unit 320 or the external communication device 310, the current control circuit 305 has priority over the sensor value of the paper thickness sensor 70. Is used.

  The A / D conversion unit 306 converts the analog voltage detected by the voltage detection unit 307 that performs voltage detection in order to perform control in a stable power state into a digital value for processing by the CPU 301 and notifies the CPU 301 of the analog voltage. It is.

  The interface 308 can be connected to an information storage element 309 such as a hard disk device. Further, the interface 308 functions as a connection unit that connects to an external communication device 310 such as a personal computer via a network line NW, and can take image data into the image forming apparatus 1 from the outside.

  In the image forming apparatus 1 according to the present embodiment, the representative smoothness (M) is determined using the smoothness detected for each of the plurality of recording sheets S in order to set a more appropriate fixing set temperature. The fixing set temperature is corrected according to the representative smoothness (M).

  As shown in FIG. 7, the representative smoothness (M) is used to determine a correction temperature by using a correction temperature table for a preset representative smoothness (M). On the other hand, the increase / decrease value of the correction temperature is determined as the fixing set temperature.

  Note that when any type detecting means of the empty sensors 131, 132, 431 and the pull-out sensors 111, 112 detects a change in the storage state of the recording sheet S, the detection value stored in the memory unit 302 is reset. Return to the original state. That is, when the detection value is reset, the above-described increase / decrease value for the correction temperature is substantially set to “0”.

  For this reason, in the present embodiment, the fixing set temperature for the fixing device 60 is obtained by using the detected value of the recording sheet S detected by the smoothness detector 80 in the memory unit 302 sequentially with the previous detected value and the subsequent detected value. Accumulate and calculate average smoothness (m). Then, the representative smoothness (M) is calculated using the average smoothness (m) and the standard deviation (δ), and the increase / decrease value is determined based on the result.

  Here, the coefficient A of the standard deviation (δ) used when calculating the representative smoothness (M) is 99.73% of the normal distribution based on the average smoothness (m) as shown in FIG. It is desirable to use “3” which is ± δ3 that can be covered.

  Further, the sheet passing number (sheet feeding number) B at the switching timing to be corrected by the calculation formula of the representative smoothness (M) may be the eighth sheet that is the sheet passing number at which the standard deviation shown in FIG. Since the larger one is desirable from the viewpoint of property, the tenth sheet is desirable.

  As a result, as shown in FIG. 10, the increase / decrease value of the correction temperature when the correction based on the representative smoothness (M) is performed as compared with the case where the correction based on the representative smoothness (M) is not performed. Can be stabilized.

  Accordingly, it is possible to provide an appropriate fixing set temperature in consideration of the correction temperature, it is possible to perform fixing at the fixing set temperature at an early stage, and it is possible to perform temperature control related to the fixing process without waste.

  Specifically, the fixing setting temperature of the fixing device 60 for the subsequent recording sheet S is determined according to the detected smoothness.

  Hereinafter, determination of the fixing set temperature according to the present embodiment will be described with reference to FIG.

  In step S1, the CPU 301 performs an image forming process using a preset initial value, that is, a fixing set temperature set by the paper thickness and smoothness of A4 plain paper normally used as the recording sheet S as an initial value. The heat source control circuit 63 is controlled to execute.

  If there is a history of executing the previous image forming process, the heat source control circuit 63 is controlled to execute the image forming process based on the previous value. At this time, whether or not there is a history of executing the previous image forming process is determined based on whether or not the detected value stored in the memory unit 302 is an initial value, and the processing number counter provided as a standard in the image forming apparatus main body 300. The counter value can be determined. In the following description, this “history of executing the previous image forming process” is simply referred to as “execution history”.

  In step S <b> 2, the CPU 301 detects the recording sheet S storing the recording sheet S or the recording sheet S stored in the manual sheet feeding device 430, in particular, the user selection by the operation unit 320 or the sheet feeding cassette 11 automatically selected by the CPU 301. In addition, the storage state of the recording sheet S is detected for the manual sheet feeding device 430.

  That is, the CPU 301 refers to the detection results of the drawer sensors 111 and 112, the storage sensor 401, the sheet set detection sensors 121 and 122, the empty sensors 131, 132, 431, and the like. Then, the CPU 301 detects whether there is a possibility that the recording sheet S has been replaced based on the reference result. The drawer sensors 111 and 112, the storage sensor 401, the sheet set detection sensors 121 and 122, and the empty sensors 131, 132, and 431 constitute storage detection means.

  It should be noted that the change of the storage state due to the detection of the empty sensors 131, 132, 431, etc. is mostly an interrupt signal, so that the recording sheet S is exchanged at the timing of step S2 shown in FIG. Not necessarily.

  In step S <b> 3, the CPU 301 detects that there is a possibility that the smoothness may change due to the replacement of the recording sheet S when executing the image forming process (step S <b> 2: YES), and turns on the flag.

  In step S <b> 4, the CPU 301 starts control of the heat source control circuit 63 using the previous value when there is an execution history and using the initial value when there is no execution history so that the fixing set temperature is reached. Further, the recording sheet S is started to be fed, and the sheet thickness sensor 70 detects the sheet thickness at the time of registration processing such as skew correction of the recording sheet S and adjustment of the secondary transfer timing by the registration device 15.

In step S5, if there is an execution history and the CPU 301 detects that the paper thickness of the recording sheet S has changed by comparing the previous value and the current value (step S5: YES), the process proceeds to step S6. Transition. On the other hand, if the CPU 301 detects that there is an execution history and the paper thickness of the recording sheet S has not changed (step S5: NO), the CPU 301 proceeds to step S7. For example, if the previous value is within the range of the amount of light received by the light receiving unit 72 corresponding to plain paper having a basis weight of 60 to 90 g / m ² , the CPU 301 receives light corresponding to the basis weight of 60 to 90 g / m ^2. The amount is set to a predetermined value, and it is determined that the paper thickness of the recording sheet S has changed when the current value deviates from the predetermined value.

  Note that the CPU 301 determines whether or not the flag is ON in the determination routine of step S5. That is, even if there is a change in the storage state and the flag is ON in step S2, it is detected that there is an execution history and the paper thickness of the recording sheet S has not changed by comparing the previous value and the current value (step S5). : NO). For example, although it is determined in step S2 that the type of the recording sheet S is changed (step S2: YES), the case where it is determined in step S5 that the type of the recording sheet S is not changed (step S5: NO) is included. . Specifically, even when the paper feed cassette 11 is pulled out or the empty sensors 131, 132, and 431 detect that the recording sheet S is empty, the same type of recording sheet S is actually replenished. There are many. In such a case, if the previous value is reset in step S3, the value used for the determination in step S5 becomes an initial value, and a satisfactory determination result cannot be obtained. Therefore, in step S3, if the flag is simply turned on, the previous value and the current value can be compared in step S5 corresponding to the simple replenishment.

  In step S <b> 6, the CPU 301 has an execution history when executing the image forming process, and detects that the type of the recording sheet S has been changed (step S <b> 5: YES). The previous value such as the detected value stored in is reset to “0”.

Therefore, the CPU 301 may indicate the following 43 in relation to the results of the determination routines in step S2 and step S5.
(1) If it is determined in step S2 that there is no change in the storage state (flag OFF), and it is determined in step S5 that there is no change in the type of the recording sheet S. If not, use the initial value.
(2) If it is determined in step S2 that there is no change in the storage state (flag OFF), and it is determined in step S5 that there is a change in the type of recording sheet S. If there is an execution history, the previous value is reset. The initial value is used, and when there is no execution history, the initial value is used.
(3) If it is determined in step S2 that the storage state has changed (flag ON) and it is determined in step S5 that the type of the recording sheet S has not been changed ... If there is an execution history, the previous value and the execution history are If not, use the initial value.
(4) If it is determined in step S2 that the storage state has changed (flag ON) and it is determined in step S5 that the type of the recording sheet S has been changed ... If there is an execution history, the previous value is reset. The initial value is used, and when there is no execution history, the initial value is used.

  Thus, the CPU 301 can control the heat source control circuit 63 with an appropriate previous value or initial value. In step (2), it is determined in step S2 that the type of recording sheet is not changed (flag OFF). In this state, it is assumed that the type of the recording sheet S stored in the paper feed cassette 11 or the manual paper feeder 430 is changed.

  In step S <b> 7, the CPU 301 starts feeding and feeding the recording sheet S, and performs a smoothness detector during registration processing such as skew correction of the recording sheet S (previous recording sheet S <b> 1) and secondary transfer timing adjustment by the registration device 15. Smoothness detection by 80 is executed.

  In step S <b> 8, the CPU 301 calculates the average smoothness (m) based on the detection value stored in the memory unit 302. Here, if not reset to the initial value in step S5, this time is the recording sheet S of the first image forming process, but the past detection values accumulated before the previous time are stored in the memory unit 302. include.

で平均平滑度（ｍ）を求めてメモリ部３０２に記憶する。 Thereby, in step S8, the CPU 301 sets the average smoothness of the detection values accumulated in the memory unit 302 to m, the detection value (variable) stored in the memory unit 302 to Xi, the number of fed recording sheets S to N, When the standard deviation is δ,

The average smoothness (m) is obtained and stored in the memory unit 302.

で標準偏差（δ）を求めてメモリ部３０２に記憶する。 In step S8, the CPU 301 determines whether the distributed formula is used.

The standard deviation (δ) is obtained and stored in the memory unit 302.

  In step S9, the CPU 301 controls the heat source control circuit 63 to change the fixing set temperature using the average smoothness (m) or the standard deviation (δ).

  Here, for example, in the case of plain paper or the like, since the smoothness is high and the change in the detection value detected by the smoothness detector 80 is small, the value of the average smoothness (m) does not change greatly. Therefore, in such a case, the CPU 301 controls the heat source control circuit 63 to change the fixing set temperature by using the average smoothness (m) or an approximate value thereof (such as a truncation process in consideration of errors).

  On the other hand, for example, when the recording sheet S having a large difference in surface irregularities and low smoothness is used, since the change in the detected value detected by the smoothness detector 80 is large, the average smoothness (m) The value changes greatly. As described above, when the smoothness fluctuation range is large, the fixing set temperature is switched for each recording sheet S, and the temperature control is not stable. Therefore, in such a case, the CPU 301 controls the heat source control circuit 63 to change the fixing set temperature by using the standard deviation (δ) or an approximate value thereof (such as a truncation process in consideration of errors).

  Next, in step S10, the CPU 301 determines whether or not the sheet passing number (N) used when calculating the average smoothness (m) has reached a predetermined number B, for example, ten.

  If the CPU 301 determines that the number of sheets to be passed (N) has not reached 10 (step S10: NO), the CPU 301 does not correct the fixing set temperature (step S11), and the fixing set temperature updated in step S9. The process proceeds to step S12.

On the other hand, if the CPU 301 determines that the number of sheets passed (N) has reached 10 (step S10: YES), it calculates the average smoothness (m) and standard deviation (δ) stored in the memory unit 302. Reference (step S12), when the representative smoothness is M and the rational number is A,
M = m−Aσ
To calculate the representative smoothness (M) (step S13).

  In step S <b> 14, the CPU 301 outputs a correction value corresponding to the representative smoothness (M) to the control unit 85. Thus, the control unit 85 controls the heat source control circuit 63 to output a control signal obtained by increasing / decreasing the correction value to the set fixing temperature, and thereafter the CPU 301 repeats the above routine until the final image forming process is completed. (Step S15).

  As described above, in the image forming apparatus of the present embodiment, the recording sheet S that stores and feeds the recording sheet S and the storage state of the recording sheet S stored in the sheet feeding cassette 11 and the like are detected. The empty sensors 131, 132, 431 or the drawer sensors 111, 112, the paper thickness sensor 70 for detecting the type of the recording sheet S, the external communication device 310, the operation unit 320, and the smoothness of the surface of the recording sheet S in a predetermined range. A smoothness detector 80 to detect, a memory unit 302 for storing a detected value of smoothness detected by the smoothness detector 80, and a fixing device for fixing the toner image transferred to the surface of the recording sheet S by heating and pressing. 60, and a control unit 85 that determines the fixing set temperature of the fixing device 60 based on the detection value recorded in the memory unit 302. The control unit 85 detects the smoothness with the smoothness detector 80. After the detected values for the recording sheets S are recorded in the memory unit 302, the smoothness of the subsequent recording sheets S is sequentially detected, and the detected values are accumulated and stored in the memory unit 302, according to the detected smoothness. The fixing temperature of the fixing device 60 for the subsequent recording sheet S is determined, and the paper thickness sensor 70, the external communication device 310, and the operation unit 320 that detect the type of the recording sheet S detect the change in the type of the recording sheet S. Sometimes, resetting the detection value stored in the memory unit 302 can contribute to shortening the change time of the fixing set temperature of the fixing device 60 when the type of the recording sheet S is changed.

  By the way, in the above-described embodiment, the case where the recording sheets S are image forming processing operations for the same print job and are all fed from the same paper feed cassette (for example, the paper feed cassette 11A) has been described. However, the present invention is not limited to this.

  For example, image forming processing for a series of print jobs using a copy function, which is from recording sheets S of different sizes (A4 and A3, etc.), that is, from different paper feed cassettes (eg, paper feed cassettes 11A, 11B). The present invention is applicable even in the case of the mixed loading mode in which paper is fed.

  Even in such a mixed loading mode, the CPU 301 simply performs switching of the paper feed cassettes 11A, 11B, etc. in accordance with the change in the size of the recording sheet S detected by the document sheet conveying apparatus 100, etc. The case where the paper thickness of the sheet S does not change is included. Therefore, if the paper thickness of the recording sheet S does not change, it is not necessary to change the previous value of the paper feed cassettes 11A and 11B, so that only the correction described above needs to be performed for the paper feed cassettes 11A and 11B. Become.

  As described above, in the image forming apparatus according to the present invention, not only when the smoothness of the recording material is predicted to be changed, but also when the type of the recording material is actually changed, fixing of the fixing unit is performed. It has the effect of being able to contribute to shortening the time for changing the set temperature, and can be applied to image forming apparatuses such as copiers, facsimiles, printers, and multifunction devices that are functionally combined with these.

1 Image forming apparatus 11A Paper feed cassette (storage means)
11B Paper feed cassette (storage means)
60 Fixing device (fixing means)
63 Heat source control circuit 70 Paper thickness sensor (type detection means)
80 Smoothness detector (smoothness detection means)
85 Control unit (temperature control means)
111 Drawer sensor (storage detection means)
112 Drawer sensor (storage detection means)
121 Sheet set detection sensor (storage detection means)
122 Sheet set detection sensor (storage detection means)
131 Empty sensor (storage detection means)
132 Empty sensor (storage detection means)
301 CPU (temperature control means)
302 Memory unit (storage means)
310 External communication equipment (type detection means)
320 Operation unit (type detection means)
401 Storage sensor (storage detection means)
430 Manual paper feeder (storage means)
431 Empty sensor (storage detection means)
S Recording sheet (recording material)

JP-A-10-160687 JP 2006-062842 A

Claims (9)

Storage means for storing and feeding the recording material;
Type detection means for detecting the type of recording material stored in the storage means;
Smoothness detecting means for detecting smoothness on the surface of the recording material;
The detection values for the previous recording material detected by the type detection means and the smoothness detection means are stored, and the detection values for the subsequent recording materials detected by the type detection means and the smoothness detection means are sequentially accumulated. Storage means for storing;
Fixing means for fixing the toner image transferred on the surface of the recording material by heating and pressing; and
Temperature control means for determining a fixing set temperature of the fixing means for subsequent recording materials based on the detection value recorded in the storage means,
When the temperature control unit detects that the type of the recording material has been changed by the type detection unit, the temperature control unit stores the detection value stored in the storage unit as the type of the recording material stored in the storage unit has been changed. An image forming apparatus, wherein the image forming apparatus is reset. The type detection means is a switch means for detecting the state of the storage means or the recording material stored in the storage means,
When the temperature control means detects that the switch means has changed the state of the storage means or the recording material stored in the storage means, the type of the recording material stored in the storage means has been changed. The image forming apparatus according to claim 1, wherein the detected value stored in the storage unit is reset as the image forming apparatus. A plurality of the storage means;
The storage means stores the detection value detected by the smoothness detection means for each of the plurality of storage means,
The type detection unit is a drawer detection switch unit that detects whether any of the plurality of storage units is pulled out from the image forming apparatus main body.
The temperature control unit changes the type of the recording material stored in the storage unit when the drawer detection switch unit detects that any of the plurality of storage units is pulled out from the main body of the image forming apparatus. The image forming apparatus according to claim 2, wherein the detection value stored in the storage unit corresponding to the storage unit is reset. A plurality of the storage means;
The storage means stores the detection value detected by the smoothness detection means for each of the plurality of storage means,
The type detection means is an empty detection switch means for detecting the presence or absence of a recording material stored in the plurality of storage means,
When the temperature detection means detects that the recording material stored in the storage means is changed when the empty detection switch means detects that the recording material is not stored in any of the plurality of storage means The image forming apparatus according to claim 2, wherein the detection value stored in the storage unit is reset corresponding to the storage unit.   The temperature control means resets the detection value stored in the storage means that the type of the recording material stored in the plurality of storage means is changed when the main power supply of the male body of the image forming apparatus is turned off. The image forming apparatus according to claim 4. A plurality of the storage means;
The storage means stores the detection value detected by the smoothness detection means for each of the plurality of storage means,
The type detection means is a position detection switch means for detecting the position of the bottom plate of the plurality of storage means,
The temperature control means changes the type of the recording material stored in the storage means when the position detection switch means detects that the position of any bottom plate of the storage means has returned to the initial position. The image forming apparatus according to claim 2, wherein the detection value stored in the storage unit corresponding to the storage unit is reset. The type detection means is an optical sensor means for detecting a paper thickness of the storage means or a recording material stored in the storage means,
The temperature control unit resets the detection value stored in the storage unit as the type of the recording material is changed when the detection value related to the paper thickness of the recording material detected by the optical sensor unit deviates from a predetermined value. The image forming apparatus according to claim 1. A plurality of the storage means;
The storage means stores detection values detected by the type detection means and the smoothness detection means for each of the plurality of storage means,
The temperature control means stores in the storage means corresponding to the storage means when the detected value of the recording material detected by the type detection means deviates from the predetermined value corresponding to the plurality of storage means. The image forming apparatus according to claim 7, wherein the detection value is reset. A plurality of the storage means;
Storage detection means for detecting the storage state of the recording material stored for each of the plurality of storage means,
The storage means stores detection values detected by the type detection means and the smoothness detection means for each of the plurality of storage means,
The temperature control means resets a detection value stored in the storage means corresponding to the storage means when the storage detection means detects a change in the storage state of the storage means. The image forming apparatus according to claim 7 or 8.

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