JP2015129884A - image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problems: sheet interval can be expanded and properly secured by controlling paper-feed timing, while productivity of an image forming apparatus is reduced due to delay of a following sheet to be fed.SOLUTION: An image forming apparatus includes: receiving means for receiving image information; image forming means for forming an image on a recording material on the basis of the image information; fixing means for fixing recording material with the image formed thereon; driving means for driving the fixing means; and control means for controlling drive of the driving means when the recording material is fixed by the fixing means on the basis of information on an area of the image formed on the recording material, to control conveyance speed of the recording material.

Description

  The present invention relates to an image forming apparatus using an electrophotographic system.

  Conventionally, in an electrophotographic image forming apparatus, in order to perform image formation at high speed, a gap between the trailing edge of the preceding sheet and the leading edge of the succeeding sheet conveyed following the preceding sheet is shortened. Image formation is performed. In such an image forming apparatus, the setting between the sheets is set so as to ensure a time in which the preceding sheet and the succeeding sheet can be detected by the sensor, for example. In addition to the sensor, when the preceding sheet is switched back to perform double-sided image formation, a time is set so that the succeeding sheet does not enter the preceding sheet.

  However, depending on the state of the image forming apparatus, there may be a case where such an appropriate sheet interval cannot be ensured. Therefore, in Patent Document 1, it is determined whether the full load is erroneously detected by the full load detection sensor by comparing the paper interval detected by the conveyance path sensor and the paper interval detected by the full load detection sensor. And when it is judged that there is a possibility that the full load may be erroneously detected by the full load detection sensor, a method is disclosed in which an appropriate paper gap is ensured by delaying the feeding timing of the subsequent paper by a predetermined time. Yes.

JP2011-221179

  However, although it is possible to widen the sheet interval by controlling the sheet feeding timing as in Patent Document 1 and to secure an appropriate sheet interval, delaying the sheet feeding timing of the subsequent sheet increases the productivity of the image forming apparatus. There was a problem that it would decrease.

  The invention according to the present application has been made in view of the above situation, and an object thereof is to widen the space between the preceding paper and the succeeding paper while suppressing a decrease in productivity.

  To achieve the above object, the present invention provides a receiving unit that receives image information, an image forming unit that forms an image on a recording material based on the image information, and a fixing that fixes the recording material on which the image is formed. And driving means for driving the fixing means, and controlling the driving of the driving means when the recording material is fixed on the fixing means based on information relating to the area of the image formed on the recording material. And a control means for controlling the conveyance speed of the recording material.

  According to the configuration of the present invention, it is possible to widen the space between the preceding paper and the succeeding paper while suppressing a decrease in productivity.

Schematic configuration diagram of an image forming apparatus Control block diagram of image forming apparatus Diagram showing the image area formed on the recording material Flow chart showing the paper spacing control method A diagram showing the relationship between the preceding and succeeding sheets Diagram showing the image area formed on the recording material Diagram showing the relationship between printing rate and transport speed Flow chart showing the paper spacing control method A diagram showing the relationship between the preceding and succeeding sheets Diagram showing the relationship between printing rate and transport speed

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the present invention.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present embodiment. When the laser beam printer 101 receives a print instruction from the video controller 202, the laser beam printer 101 starts image formation. First, the recording material S as paper is picked up and fed from the paper feed cassette 102 by the paper feed roller 103. The fed recording material S is conveyed to the top sensor 104. When the top sensor 104 detects the leading edge of the recording material S, the recording material S is conveyed to the image forming unit 207.

  The image forming unit 207 includes a photosensitive drum 105, a transfer roller 106, a charging roller 107, and a developing device 108. First, the photosensitive drum 105 is uniformly charged by the charging roller 107. Thereafter, an electrostatic latent image is formed on the surface of the photosensitive drum 105 by the laser light L emitted from the laser exposure device 109. Note that the laser exposure device 109 irradiates the laser light L based on the image data 204 as image information transmitted from the video controller 202. The electrostatic latent image formed on the photosensitive drum 105 is visualized as a toner image by being attached with toner by the developing device 108. Then, the photosensitive drum 105 rotates to convey the toner image to the transfer position, and the recording material S is also conveyed to the transfer position in synchronization with the rotation of the photosensitive drum 105.

  At the transfer position, a voltage having a reverse polarity to the toner image is applied to the transfer roller 106, and the toner image on the photosensitive drum 105 is transferred to the recording material S. The recording material S to which the toner image has been transferred is conveyed to the fixing device 110, and is heated and pressurized by the fixing device 110, so that the toner image is fixed on the recording material S. The recording material S on which the toner image is fixed is conveyed by the paper discharge roller 111 and discharged onto the paper discharge tray 112. Although not shown, the fixing device 110 and the paper discharge roller 111 are driven by the same drive motor. The full load detection sensor unit 160 includes a lever member 161 and a photo interrupter type sheet detection sensor unit 162 disposed above the lever member 161. A shielding part is provided on the base end side of the lever member 161, and the state of the lever member 161 can be detected by the shielding part shielding the sheet detection sensor part 162. When the sheet detection sensor unit 162 is shielded by the shielding unit for a predetermined time or longer or is not shielded for the predetermined time or longer, it can be determined that the paper discharge tray 112 is full of the recording material S.

  Although an example of an image forming apparatus that forms a monochrome image has been described here as an example, the present invention is also applicable to an intermediate transfer type image forming apparatus in which a color image formed on an intermediate transfer belt is transferred to a recording material. Is possible. The present invention can also be applied to a direct transfer type image forming apparatus in which an image is transferred from a photosensitive drum to a recording material conveyed to a recording material conveyance belt to form a color image.

  FIG. 2 is a control block of the image forming apparatus in the present embodiment. The laser beam printer 101 includes an operation panel 212 that displays the state of the image forming apparatus, a video controller 202 that generates image data to be printed and a print instruction, and an engine control unit 203 that controls each member in the image forming apparatus. ing. When the video controller 202 receives a print instruction from the PC 213 that is an external device, the video controller 202 calculates a distance L1 from the leading edge position of the recording material S to the trailing edge position of the image to be formed as shown in FIG. . In other words, the distance L1 from the leading edge position of the recording material S to the leading edge position of the image margin is calculated. The distance L1 can be obtained by analyzing the image data and calculating the rear end position of the image in the recording material conveyance direction. The video controller 202 notifies the engine control unit 203 of the distance L1 calculated by the communication line 205. Further, a print start instruction is notified to the engine control unit 203.

  Here, as an example, the method of calculating the distance L1 by the video controller 202 has been described, but the present invention is not limited to this. It is also possible to transmit the image data 204 from the video controller 202 to the engine control unit 203, and the engine control unit 203 calculates the distance L1. Although an example in which the video controller 202 and the engine control unit 203 are configured with different CPUs has been shown here, it may be configured with the same CPU.

  When receiving an instruction from the video controller 202, the engine control unit 203 starts a series of image forming operations. In a series of image forming operations, the paper feed control unit 206 starts feeding the recording material S, and the image forming unit 207 forms an image. Then, the operation is performed until the image formed on the recording material S is thermally fixed by the fixing device 110 and the fixed recording material S is discharged to the paper discharge tray. The fixing sensor 113 detects the leading edge and the trailing edge of the recording material S on the downstream side of the fixing device 110, and can detect a winding jam of the recording material S in the fixing device 110. The full load detection sensor unit 160 is a sensor that detects the stacked state of the recording materials S stacked on the paper discharge tray. If the trailing edge of the recording material S cannot be detected even after a predetermined time has elapsed since the leading edge of the recording material S has been detected, it can be determined that the recording material S is full on the paper discharge tray. . When the full load is detected, the engine controller 203 notifies the video controller 202 of the full load via the communication line 205.

  In this full load detection by the full load detection sensor unit 160, if the space between the preceding paper and the succeeding paper that is conveyed following the preceding paper becomes narrow, the recording material S is not fully loaded in the paper discharge tray yet. There is a possibility of false detection. In other words, when continuous printing is performed in a state where the gap between the sheets is narrow, for example, when the preceding sheet is discharged to the sheet discharge tray, the lever member 161 that operates in response to the leading end of the preceding sheet entering the The leading edge of the succeeding paper may enter before returning to the initial state due to the missing edge. Therefore, the trailing edge of the preceding sheet cannot be detected, and the detection result is as if the same recording material is continuously detected by the full load detection sensor unit 160, and may be erroneously detected as full. There is. In this way, when the paper gap is narrow, widening the paper gap can secure the time for the lever member 161 to sufficiently return to the initial state after the trailing edge of the preceding paper is pulled out, thereby suppressing erroneous detection. can do.

  In order to widen the gap between sheets without reducing productivity, it is possible to accelerate between the time when the preceding sheet is fed and the time when the preceding sheet is fed, with the interval between feeding the preceding sheet and the following sheet remaining unchanged. It is done. However, since it is desirable to form the image without misalignment between the feeding of the recording material and the transfer of the image onto the recording material, it is desirable to match the speed of the conveyance of the recording material and the formation of the image. It is not preferable to control the conveyance speed in order to widen the width. Although it is conceivable to control the conveyance speed of the recording material after the recording material passes through the fixing device 110 and is discharged, the image forming apparatus has been downsized and discharged after fixing. It is conceivable that the paper interval cannot be sufficiently widened until the period up to.

  Therefore, in the present embodiment, after the front end of the recording material S is detected by the fixing sensor 113, the recording material S is conveyed by a distance L1 that is a region where the previously obtained image is formed. Control is performed such that the conveyance speed of the recording material S is accelerated and the space between the preceding sheet and the succeeding sheet is increased. In this way, it is possible to perform control to widen the sheet interval before the trailing edge of the recording material S passes through the fixing device 110. In particular, in a miniaturized image forming apparatus, it is possible to ensure the sheet interval. Become advantageous. In order to reduce the cost of the image forming apparatus, it can be considered that the fixing device 110 and the discharge roller are driven in a common configuration. Even in such a case, since the recording material S can be accelerated before the rear end of the recording material S passes through the fixing device 110, it is advantageous to ensure the space between the sheets.

  Note that the conveyance speed is accelerated after the recording material S is conveyed by the distance L1 because the area where the toner image is transferred is conveyed at a predetermined conveyance speed according to the type of the recording material S, thereby fixing. This is to keep the sex. In this embodiment, since the area where the toner image is transferred is calculated as the distance L1, it is possible to determine the area where the toner image is not formed on the recording material S. That is, the presence / absence of a toner image can be analyzed from the image information as information relating to the image area. Since the speed of the recording material S is accelerated in the area where the toner image is not formed, it is possible to widen the gap between sheets while suppressing a decrease in fixability.

  FIG. 4 is a flowchart showing a paper gap control method according to this embodiment. Here, as an example, the operation when performing continuous printing of the preceding sheet and the succeeding sheet will be described. FIG. 5 is a diagram illustrating the relationship between the preceding sheet and the succeeding sheet in the present embodiment. Specifically, the distance L1 from the leading edge of the preceding paper to the trailing edge of the image formed on the preceding paper, the distance L2 from the leading edge of the trailing sheet to the trailing edge of the image to be formed on the trailing sheet, and the interval between the leading sheet and the trailing sheet It is the figure which showed a certain paper gap L3. The sheet interval L3 can be set for each image formation, and can be measured by the time from when the trailing edge of the preceding sheet is detected by the top sensor 104 until the leading edge of the succeeding sheet is detected. Further, here, the interval between sheets, which is the interval at which the full load detection sensor unit 160 can detect the full load of the recording material S, is L4.

  In step S401, when the engine control unit 203 receives a print start instruction from the video controller 202, the engine control unit 203 sets the feeding timing of the preceding sheet and the succeeding sheet so that the sheet interval L3 is obtained. In step S402, the engine control unit 203 stores a distance L1 from the leading edge of the preceding sheet to the trailing edge of the image formed on the preceding sheet, and a distance L2 from the leading edge of the succeeding sheet to the trailing edge of the image to be formed on the trailing sheet. . The distances L1 and L2 may be received from the video controller 202, or may be obtained by the engine control unit 203 from each image data. In step S <b> 403, the engine control unit 203 compares the space L <b> 3 between the preceding sheet and the succeeding sheet and the sheet interval L <b> 4 that is an interval at which the full load detection sensor unit 160 can detect the full load of the recording material S. If L3 ≧ L4, it is determined that the full load detection sensor 160 can detect the full load, and the process proceeds to S410. If L3 <L4, it is determined that there is a possibility that the full load detection sensor unit 160 may erroneously detect the full load, and the process proceeds to S404.

  In step S <b> 404, the engine control unit 203 determines whether the fixing sensor 113 has detected the leading edge of the preceding sheet. When the leading edge of the preceding sheet is detected, in step S405, the engine control unit 203 obtains a timing T1 until the trailing edge of the image formed on the preceding sheet is fixed by the fixing device 110 from the conveyance speed and distance L1 of the preceding sheet. In step S406, the engine control unit 203 determines whether the timing T1 obtained in step S405 has elapsed. When T1 has elapsed, in step S407, the engine control unit 203 accelerates the conveyance speed of the preceding sheet in order to widen the sheet interval L3. As a result, the control is performed so that the paper gap L3 is equal to or greater than the paper gap L4, or at least the paper gap L3 approaches the paper gap L4.

  In step S <b> 408, the engine control unit 203 obtains a timing T <b> 2 for returning the speed of the fixing device 110 to the fixing speed of the subsequent paper before the leading edge of the subsequent paper enters the fixing device 110. In FIG. 5, since the image is formed from the leading edge of the succeeding paper, the speed of the fixing device 110 is returned to the fixing speed of the succeeding paper until the leading edge of the succeeding paper enters the fixing device 110. Depending on the position of the image formed on the succeeding paper, even after the leading edge of the succeeding paper has entered the fixing device 110, the leading edge of the image to be formed on the succeeding paper may not reach the fixing device 110. It is sufficient that the fixing speed is controlled. In step S409, when T2 has elapsed, the engine control unit 203 controls the fixing device 110 so that the speed of the fixing device 110 becomes the fixing speed of the subsequent sheet. In S410, if there is no image to be subsequently formed, the engine control unit 203 ends the image forming operation.

  In addition, here, as an example, the explanation has been made to widen the sheet space in order to suppress erroneous detection by the full load detection sensor unit 160, but the present invention is not limited to this. For example, the sheet interval may be widened in order to secure a period for detecting the fixing wrap jam by the fixing sensor 113, or the sheet interval may be secured in order to ensure a period for switching back the preceding sheet on the duplex conveyance path. You can spread it.

  As described above, after the leading end of the recording material S is detected by the fixing sensor 113, the recording material S is conveyed from the position where the recording material S is conveyed by the distance L1 that is the area where the previously obtained image is formed. Control is performed to increase the speed and widen the space between the preceding paper and the following paper. By doing so, it is possible to perform control to widen the sheet interval before the trailing edge of the recording material S passes through the fixing device 110, and suppresses the decrease in productivity, and the preceding sheet and the succeeding sheet after fixing. The space between the papers can be widened.

(Second Embodiment)
In the first embodiment, the method of controlling the timing for accelerating the preceding paper according to the area of the image formed on the preceding paper has been described. In the present embodiment, a method for controlling the timing for accelerating the preceding paper according to the printing rate (density) of the image formed on the preceding paper will be described. In the present embodiment, differences from the first embodiment will be described, and the description of the same configuration as the first embodiment, such as the configuration of the image forming apparatus, is omitted here.

  When receiving a print instruction from the PC 213, the video controller 202 divides the recording material S into a plurality of regions (regions 1, 2, and 3) for the image to be formed as shown in FIG. Then, distances L5 and L6 to the change point of the printing rate and printing rates 1, 2, and 3 are calculated. In other words, the distance L5 from the tip position of the recording material S to the first printing rate change point and the distance L6 from the recording material tip position to the second printing rate change point are calculated. Here, the printing rate is the ratio of the image forming area to the area on the recording material. Here, as an example, the change point of the first printing rate is 90%, and the changing point of the second printing rate is 25%. However, the present invention is not limited to this, and the number of changing points of the printing rate can be arbitrarily set according to the fixing property to be obtained.

  The printing rate can be obtained as a ratio of the area on the recording material and the image forming area in the area on the recording material sequentially from the leading end side in the conveyance direction of the recording material S by analyzing the image data. As shown in FIG. 6, the distances L5 and L6 are calculated by obtaining the change point of the first print rate and the change point of the second print rate and obtaining the distance from the leading end of the recording material S to each change point. Can do. The video controller 202 notifies the engine control unit 203 of the distances L5 and L6 calculated by the communication line 205 and the printing rates 1, 2, and 3. Further, a print start instruction is notified to the engine control unit 203.

  Here, as an example, the method of calculating the distances L5 and L6 and the printing rates 1, 2, and 3 by the video controller 202 has been described, but the present invention is not limited to this. It is also possible to transmit the image data 204 from the video controller 202 to the engine control unit 203, and the engine control unit 203 can calculate the distances L5 and L6 and the printing ratios 1, 2, and 3. Although an example in which the video controller 202 and the engine control unit 203 are configured with different CPUs has been shown here, it may be configured with the same CPU.

  According to the calculated printing rate, the acceleration limit speed of the fixing motor is provided as shown in FIG. 7, and the conveyance speed of the recording material S is controlled. After the leading edge of the recording material S is detected by the fixing sensor 113, when the recording material S is conveyed by the distances L5 and L6, the conveyance speed of the recording material S is accelerated and the space between the preceding paper and the succeeding paper is increased. Control to spread. In this way, it is possible to perform control to widen the sheet interval before the trailing edge of the recording material S passes through the fixing device 110. In particular, in a miniaturized image forming apparatus, it is possible to ensure the sheet interval. Become advantageous. In order to reduce the cost of the image forming apparatus, it can be considered that the fixing device 110 and the discharge roller are driven in a common configuration. Even in such a case, since the recording material S can be accelerated before the rear end of the recording material S passes through the fixing device 110, it is advantageous to ensure the space between the sheets.

  Note that the reason why the conveyance speed is accelerated from the point where the recording material S is conveyed by the distances L5 and L6 is to maintain the fixability by conveying the recording material S at a predetermined conveyance speed according to the printing rate of the formed toner image. It is. In this embodiment, the recording material S is conveyed at a speed of 300 mm / s in the area 1, 330 mm / s in the area 2, and 370 mm / s in the area 3. That is, as the information related to the image area, the printing rate of the toner image can be analyzed from the image information. Since the speed of the recording material S is accelerated in a region where the printing rate of the toner image is low, it is possible to widen the gap between sheets while suppressing a decrease in fixability.

  FIG. 8 is a flowchart showing a paper spacing control method in this embodiment. Here, as an example, the operation when performing continuous printing of the preceding sheet and the succeeding sheet will be described. FIG. 9 is a diagram showing the relationship between the preceding sheet and the succeeding sheet in the present embodiment. Specifically, the distance L5 from the leading edge position of the preceding paper to the first printing rate change point, the distance L6 from the leading edge position of the recording material to the second printing rate changing point, and the third edge from the leading edge position of the succeeding paper. FIG. 6 is a diagram illustrating a distance L7 to a change point of the printing rate and a space L8 between the preceding sheet and the succeeding sheet. Note that the sheet interval L8 can be set for each image formation, and can be measured by the time from when the trailing edge of the preceding sheet is detected by the top sensor 104 until the leading edge of the subsequent sheet is detected. Further, here, the sheet interval, which is the interval at which the full load detection sensor unit 160 can detect the full load of the recording material S, is L9. FIG. 10 is a diagram showing the acceleration limit speed of the fixing motor according to the printing rate of each area in the present embodiment.

  In step S <b> 801, upon receiving a print start instruction from the video controller 202, the engine control unit 203 sets the sheet feeding timing for the preceding sheet and the succeeding sheet so that the sheet interval L <b> 8 is reached. In step S802, the engine control unit 203 determines the distance L5 from the leading edge position of the preceding sheet to the first printing rate changing point, the distance L6 from the leading edge position of the recording material to the second printing rate changing point, The distance L7 from the tip position to the third printing rate change point is stored. The distances L5, L6, and L7 may be received from the video controller 202, or may be obtained from the respective image data by the engine control unit 203. In step S <b> 803, the engine control unit 203 compares the space L <b> 8 between the preceding sheet and the succeeding sheet and the sheet interval L <b> 9 that is an interval at which the full load detection sensor unit 160 can detect the full load of the recording material S. If L8 ≧ L9, it is determined that the full load detection sensor 160 can detect the full load of the recording material S, and the process proceeds to S818. If L8 <L9, it is determined that there is a possibility that the full load detection sensor unit 160 may erroneously detect the full load, and the process proceeds to S804.

  In step S804, the engine control unit 203 determines whether the fixing sensor 113 has detected the leading edge of the preceding sheet. When the leading edge of the preceding paper is detected, in S805, the engine control unit 203 determines from the speed 1 and distance L5 when the preceding paper area 1 is fixed until the fixing device 110 finishes fixing the area 1 on the preceding paper. Find T3. In step S806, the engine control unit 203 determines whether the timing T3 obtained in step S805 has elapsed. When T3 has elapsed, in S807, the engine control unit 203 accelerates the fixing motor speed from speed 1 to speed 2 in accordance with the printing rate in area 2, as shown in FIG. As a result, the control is performed so that the paper gap L8 is equal to or greater than the paper gap L9, or at least the paper gap L8 approaches the paper gap L9. The fixing motor speed corresponding to each area is stored in advance in a memory (not shown) or the like.

  In step S808, the engine control unit 203 obtains a timing T4 until the fixing device 110 finishes fixing the area 2 on the preceding paper from the speed 2 and the distance (L6-L5) when the preceding paper area 2 is fixed. In step S809, the engine control unit 203 determines whether the timing T4 obtained in step S808 has elapsed. When T4 elapses, in S810, the engine control unit 203 increases the fixing motor speed from speed 2 to speed 3 in accordance with the printing rate in the area 3, as shown in FIG. As a result, the control is performed so that the paper gap L8 is equal to or greater than the paper gap L9, or at least the paper gap L8 approaches the paper gap L9.

  In step S811, the engine control unit 203 determines the timing until the fixing unit 110 finishes fixing the area 3 on the preceding sheet from the speed 3 and the distance (the preceding sheet length−L6) when the preceding sheet area 3 is fixed. Find T5. In S812, the engine control unit 203 determines whether or not the timing T5 obtained in S811 has elapsed. When T5 elapses, in S813, the engine control unit 203 changes the motor fixing speed from speed 3 to speed 4 as shown in FIG.

  In step S <b> 814, the engine control unit 203 determines whether the fixing sensor 113 has detected the leading edge of the subsequent sheet. When the leading edge of the succeeding sheet is detected, in S815, the engine control unit 203 obtains a timing T6 until the fixing device 110 finishes fixing the area 4 on the succeeding sheet from the speed 4 and the distance L7 that are the conveying speed of the succeeding sheet. In S816, the engine control unit 203 determines whether or not the timing T6 obtained in S815 has elapsed. When T6 has elapsed, the engine control unit 203 changes the fixing motor speed from the speed 4 to the speed 5 according to the printing rate in the area 5 as shown in FIG. In S818, if there is no image to be subsequently formed, the engine control unit 203 ends the image forming operation.

  In addition, here, as an example, the explanation has been made to widen the sheet space in order to suppress erroneous detection by the full load detection sensor unit 160, but the present invention is not limited to this. For example, the sheet interval may be widened in order to secure a period for detecting the fixing wrap jam by the fixing sensor 113, or the sheet interval may be secured in order to ensure a period for switching back the preceding sheet on the duplex conveyance path. You can spread it. In the present embodiment, the fixing motor speed is changed for each region as an example, but the present invention is not limited to this. If a sheet interval necessary for full load detection has already been secured in a certain area, it is possible to control so that the conveyance speed of the recording material S is not accelerated in the subsequent areas.

  As described above, after the front end of the recording material S is detected by the fixing sensor 113, the distance L5, L6, and L7, which are regions where the printing rate of the image formed on the recording material S changes, are conveyed. Control is performed such that the conveyance speed of the recording material S is accelerated and the space between the preceding sheet and the succeeding sheet is increased. By doing so, it is possible to perform control to widen the sheet interval before the trailing edge of the recording material S passes through the fixing device 110, and suppresses the decrease in productivity, and the preceding sheet and the succeeding sheet after fixing. The space between the papers can be widened.

110 Fixing Unit 203 Engine Control Unit

Claims (10)

Receiving means for receiving image information;
Image forming means for forming an image on a recording material based on the image information;
Fixing means for fixing the recording material on which the image is formed;
Driving means for driving the fixing means;
Control means for controlling the conveyance speed of the recording material by controlling the driving of the driving means when the recording material is fixed to the fixing means, based on the information on the area of the image formed on the recording material; An image forming apparatus comprising:   The control means controls the drive of the driving means when the preceding paper, which is a recording material conveyed in advance, is fixed on the fixing means, so that the preceding paper and the preceding paper are followed. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled so as to widen a gap between papers that are transported in succession.   The image forming apparatus according to claim 2, wherein the control unit performs control to increase a gap between the sheets by accelerating a conveyance speed of the preceding sheet.   4. The image forming apparatus according to claim 1, further comprising a calculation unit configured to calculate information related to a region of the image formed on the recording material based on the image information.   The image forming apparatus according to claim 4, wherein the calculation unit calculates the presence or absence of an image as information relating to the area of the image.   The image forming apparatus according to claim 4, wherein the calculation unit calculates a printing rate of an image to be formed as information relating to the area of the image.   The control means determines the conveyance speed of the recording material when the area without the image is fixed by the fixing means from the conveyance speed of the recording material when the area where the image exists is fixed by the fixing means. 6. The image forming apparatus according to claim 5, wherein the image forming apparatus is controlled to be faster.   The control unit has a second printing rate that is lower than the first printing rate by the fixing unit than the conveyance speed of the recording material when the region having the first printing rate is fixed by the fixing unit. The image forming apparatus according to claim 6, wherein the image forming apparatus is controlled so that a conveyance speed of the recording material when the area is fixed is higher. Stacking means for stacking the recording material fixed on the fixing means;
Detecting means for detecting the recording material loaded on the loading means,
The image forming apparatus according to claim 2, wherein the control unit controls the gap between the sheets so that the detection unit can detect the recording material. A conveying unit that conveys the recording material fixed to the fixing unit;
The image forming apparatus according to claim 1, wherein the fixing unit and the conveying unit are driven by the common driving unit.

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