JP5422959B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer or a copying machine, and relates to sheet conveyance control for improving the winding of a sheet around a fixing belt that occurs in a fixing unit.

  In multicolor image forming apparatuses such as full-color printers and spot color printers, a plurality of photosensitive drums are arranged along the traveling direction of an intermediate transfer belt composed of an endless belt, and electrostatic latent images formed on the respective photosensitive drums are arranged. There is a tandem system in which toners of different colors are adsorbed to form a toner image and sequentially transferred onto a transfer belt.

  In such an image forming apparatus, usually, the sheets stacked on the sheet feeding device are fed out one by one, and the fed-out paper is conveyed toward the transfer position of the toner image.

  In the transport control, the paper is temporarily stopped by a pair of registration rollers before the transfer position, and the pair of registration rollers is driven in time with the toner image transported on the intermediate transfer belt to feed the paper to the transfer position. Is generally known.

  In an image forming apparatus, generally, a toner image is melted and pressed and fixed on a sheet by a fixing device.

  As such a fixing device, it is stretched between a roller type fixing device composed of an upper heat roller and a lower pressure roller (including a lower heat roller) and a plurality of belt conveying rollers having a structure in which the fixing temperature is further suppressed. There is a fixing device of a fixing belt type comprising an endless fixing belt that rotates and a pressure roller (including a heating roller).

  These fixing devices include an oil application mechanism, and supply paper peeling oil to a heating roller and a fixing belt to prevent paper jam that occurs in the fixing device.

  Further, in Patent Document 1 of the conveyance control of a roller type fixing device composed of an upper heat roller and a lower pressure roller (including a lower heat roller), since a single oil application mechanism method is adopted, a sheet to be printed on the back side is used. When transporting to the fixing device, a method of uniformly applying oil to the lower heat roll is used by leaving a transport interval of one rotation or more of the lower heat roller without an oil application mechanism between the preceding paper. Yes.

In a fixing belt type fixing device, a method is generally used in which an oil application mechanism is provided on each of the fixing belt side and the pressure roller side so that oil is uniformly applied and the paper is conveyed without leaving a paper interval.
Japanese Patent Laid-Open No. 2003-43844

  A fixing belt type fixing device that provides an oil application mechanism on each of the fixing belt side and the pressure roller side to uniformly apply oil is used for continuous printing of coated paper or paper with low hygroscopicity. The oil can be kept uniform. However, in the case of an envelope or a non-coated paper with high moisture absorption, the paper absorbs oil applied to the fixing belt at the time of fixing and consumes a lot of oil. At this time, there arises a problem that the sheet peelability of the fixing belt is lowered, and the sheet is wound around the fixing belt to cause a sheet jam. In particular, envelopes and paper with high hygroscopicity have a problem that the hygroscopicity varies greatly depending on the environment and easily causes paper jam.

  In order to solve this problem, it is effective to increase the amount of oil applied to the fixing belt, but if the amount of oil applied to the fixing belt is increased, the amount of oil applied will be excessive, causing problems such as oil scattering and oil dripping. Occur.

  The present invention relates to printing on highly hygroscopic paper such as an envelope or printing in an environment where the paper has high hygroscopicity, without changing the oil application mechanism of the fixing device. An object of the present invention is to provide an image forming apparatus capable of stably supplying a peeling oil and preventing a paper jam.

In order to solve the above problems, according to the present invention, as described in claim 1, a toner image that is a latent image formed on an intermediate transfer belt by appropriately stopping a sheet conveyed from a sheet feeding unit on a conveyance path. A transport control unit that transports the paper to which the toner image is transferred to the fixing unit and fixes the toner image onto the paper with the fixing device and discharges the toner image. An endless fixing belt that is wound around and rotated between a plurality of belt conveying rollers, and a pressure that presses a portion of the fixing belt that is wound around a fixing roller that is one of the plurality of belt conveying rollers. provided with a roller, the fixing belt and the pressure roller is provided with an oil coating mechanism for supplying the paper separation oil, the oil applying mechanism provided in the fixing belt provided with oil blade to adjust the oil supply, In order to realize the supply of the specified sheet peeling oil, the conveyance control unit conveys the sheet to the fixing device at a conveyance interval of one rotation or more of the fixing belt set according to the type of the sheet. Is the gist.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the conveyance interval is a length obtained by adding a margin length to a length corresponding to one rotation of the fixing belt, and a sheet conveyance speed. It can be set as the conveyance interval based on the above.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the conveyance control unit sets a conveyance interval that is equal to or greater than one rotation of the fixing belt according to the thickness of the sheet to be conveyed. can do.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, the conveyance control unit includes the fixing belt 1 according to the temperature and humidity of the paper feeding unit in addition to the type of the paper. It is possible to set a conveyance interval equal to or greater than the rotation amount.

According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, the transport control unit transports the fixing belt for one rotation or more depending on an in-machine temperature and humidity in addition to the type of the paper. An interval can be set.

According to a sixth aspect of the present invention, in the image forming apparatus according to the first aspect, in addition to the type of the sheet, the conveyance control unit is equal to or more than one rotation of the fixing belt depending on a set fixing temperature. A conveyance interval can be set.

Further, as described in claim 7, carried in the image forming apparatus according to claim 1, wherein the conveyance control unit, when continuously conveying the sheet to be conveyed at a conveyance interval, the first sheet Thereafter, the conveyance interval can be conveyed as a conveyance interval equal to or longer than one rotation of the fixing belt .

  In the image forming apparatus of the present invention, in printing on highly hygroscopic paper such as an envelope or printing in an environment where the paper has high hygroscopicity, fixing without changing the oil application mechanism of the fixing device. It is possible to stably supply sheet peeling oil from the oil application mechanism to the belt, thereby preventing sheet jamming.

  In the present embodiment, in printing on highly hygroscopic paper such as an envelope or printing in an environment where the hygroscopicity of the paper is high, the oil application mechanism is applied to the fixing belt without changing the oil application mechanism of the fixing device. An object of the present invention is to stably supply paper peeling oil and prevent paper jam. For this purpose, in the operation of stopping the sheet appropriately in the conveyance path of the conveyance control unit and conveying the sheet to the transfer unit in accordance with the toner image latent image on the intermediate transfer belt, the next sheet is conveyed to the transfer unit and then the next. The conveyance interval until the sheet is conveyed to the transfer unit is set as a conveyance interval based on one rotation of the fixing belt depending on the type of sheet, the thickness of the sheet, and the environment, and control for conveying the sheet to the fixing device is performed. Realized by adding to the transport device.

  The present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of a four-color full-color image forming apparatus using a paper transport device of a transport paper standby system according to an embodiment of the present invention.

  The image forming apparatus includes four image forming units 1 a, 1 b, 1 c, and 1 d arranged along the traveling direction of the intermediate transfer belt 10. The image forming unit 1a includes a photosensitive drum 2a as an image carrier, a drum charger 3a, an exposure device 4a, a developing device 5a, a transfer device 6a, a cleaning device 7a, and the like. The image forming units 1b to 1d are configured similarly to 1a. Assume that the image forming units 1a to 1d form images of different colors, for example, the image forming unit 1a is yellow, 1b is magenta, 1c is cyan, and 1d is black.

  When such a photosensitive drum 2a receives an image forming operation start instruction signal from a print control device (not shown), the photosensitive drum 2a starts rotating in the direction of (a) in the drawing and continues rotating until the image forming operation ends. When the photosensitive drum 2a starts rotating, a high voltage is applied to the drum charger 3a, and negative charges are uniformly charged on the surface of the photosensitive drum 2a. When the character data or graphic data converted into a dot image is sent from the print control device (not shown) to the image forming device as an on / off signal of the exposure device 4a, the exposure device 4a has the surface of the photosensitive drum 2a. A portion irradiated with the laser light and a portion not irradiated are formed. When the portion of the photosensitive drum 2a whose charge has been reduced by the laser beam irradiation from the exposure device 4a reaches a position facing the developing device 5a, the portion of the photosensitive drum 2a where the charge has been reduced is charged with a negative charge. The attracted toner is attracted to form a toner image.

  When the toner image formed on the photosensitive drum 2a reaches the transfer device 6a as the primary transfer means, the toner image is transferred in the direction of arrow A in the figure by the action of a high voltage applied to the transfer device 6a. The image is transferred onto the intermediate transfer belt 10. Note that the toner remaining without being transferred onto the photosensitive drum 2a even after passing through the transfer position (image transfer portion) is cleaned by the cleaning device 7a and is prepared for the next image forming operation.

  An image forming operation is performed in the same manner in the image forming unit 1b following the image forming unit 1a, and the toner image formed on the photosensitive drum 2b is applied to the intermediate transfer belt 10 by the action of a high voltage applied to the transfer device 6b. Transcribed.

  At this time, the timing at which the image formed by the image forming unit 1 a and transferred onto the intermediate transfer belt 10 reaches the transfer device 6 b and the toner image formed on the photosensitive drum 2 b are transferred to the intermediate transfer belt 10. By matching the transfer timing, the toner images formed by the image forming unit 1a and the image forming unit 1b are overlapped on the transfer belt 10. Similarly, a full color image is formed on the intermediate transfer belt 10 by superimposing the toner images formed by the image forming units 1 c and 1 d on the intermediate transfer belt 10.

  At the same time when this full-color image reaches the paper transfer device 9 as the secondary transfer means, the paper 8 conveyed in the direction of arrow D in the figure from the paper supply device 17 of the image forming apparatus reaches the paper transfer device 9. The full color image on the intermediate transfer belt 10 is transferred to the paper 8 by the action of the high voltage applied to the paper transfer device 9. When the full color image is transferred, the sheet 8 is conveyed to the fixing device 11 by the conveying belt 18.

  When the paper 8 is conveyed to the fixing device 11, the toner image on the paper 8 is melted and fixed on the paper 8. After the full-color image passes through the position of the sheet transfer device 9, the untransferred toner remaining on the intermediate transfer belt 10 is cleaned by the belt cleaning mechanism 12. The paper 8 that has passed through the fixing device 11 is conveyed in the direction of arrow E in the figure. The paper 8 to be printed on the back side with this paper 8 is transported in the machine and reaches the pair of transport rollers 14g. The paper 8 is temporarily stopped at a paper stop point 16c, and is prepared for transport for back side printing. Alternatively, the paper 8 that has passed through the fixing device 11 is transported in the direction of arrow E in the figure and discharged from the image forming apparatus.

  The paper supply device 17 includes paper stacking units 19a and 19b and paper supply units (calling rollers, paper supply rollers, separation rollers, and grip rollers) 20a and 20b.

  When the paper feeding unit 20a receives a paper feeding start instruction signal from a printing apparatus control device (not shown), the paper feeding unit 20a starts to rotate the calling roller, the paper feeding roller, the separation roller, and the grip roller. The calling roller of the paper stacking unit 19a feeds the paper 8 and transports it to the paper feed roller and the separation roller in the previous transport path. The upper sheet 8 fed from the calling roller is fed by the sheet feeding roller and conveyed to the grip roller. The separation roller rotates reversely to the paper feed roller and pushes back the lower paper 8 fed from the calling roller to the paper stacking portion 19a. The paper 8 transported by the paper feed roller is transported by the grip roller to the previous transport roller pair 14a, 14b. The conveyance roller pairs 14a and 14b convey the paper 8 to the conveyance roller pair 14c. The transport roller pair 14c reaches the transport roller pair 14g when the paper 8 is in the previous transport path, or reaches the transport roller pair 14g for backside printing, and the paper 8 is temporarily stopped at the paper stop point 16c. When the transport of No. 8 is first, the transport of the paper 8 is temporarily stopped at the paper stop point 16a, and the transport timing is waited.

  Upon receiving a paper feed start instruction signal from a printing apparatus control device (not shown), the paper feed unit 20b feeds the paper 8 from the paper stacking unit 19b and transports the paper 8 to the transport roller pair 14c. Similarly to the paper 8 from the paper supply unit 20a, the conveyance roller pair 14c temporarily stops the conveyance of the paper 8 at the paper stop point 16a as necessary, and waits for the conveyance timing. The conveyance roller pair 14c conveys the paper 8 to the conveyance roller pair 14d at the conveyance timing. The conveyance roller pair 14d conveys the paper 8 in the direction of arrow C and conveys it to the conveyance roller pair 14e. The conveyance roller pair 14 e conveys the paper 8 to the registration roller pair 13. The registration roller pair 13 conveys the sheet 8 to the sheet stop point 16b and asks the conveyance timing. The registration roller pair 13 transfers the paper 8 so that the paper transfer full-color image transferred onto the intermediate transfer belt 10 reaches the paper transfer device 9 as the secondary transfer means, and at the same time, conveys the paper 8 to the paper transfer device 9. It is conveyed to the timing roller pair 15. The timing roller 15 finely adjusts the paper transfer position of the full color image by adjusting the acceleration timing of the rotation speed.

  Further, temperature / humidity sensors 21a, 21b and 21c for detecting the temperature / humidity in the apparatus and the temperatures / humidities of the paper stacking sections 19a, 19b are arranged so that the temperature / humidity can be monitored.

  FIG. 2 is an enlarged configuration diagram showing the fixing device 11. The fixing device 11 supports the endless fixing belt 24, which is a belt member, from the back side of the loop by the fixing roller 22 and the heating roller 23, which are stretching members, and is stretched while being pressed by the tension roller 26 from the front side of the belt. Yes. The fixing belt 24 rotates in the clockwise direction of the fixing roller 22 and the heating roller 23 in the drawing. A pressure roller 25 is disposed below the fixing roller 22. The pressure roller 25 is pressed toward the fixing roller 22 as a back-side roller that contacts the back surface while contacting the loop surface of the fixing belt 24. Thus, a fixing nip is formed in which the fixing belt 24 and the pressure roller 25 are in contact with each other in the surface movement direction. When the sheet 8 on which the full-color image has been transferred passes through the fixing nip surface 41, the toner of the full-color image transferred on the sheet is melt-pressed to fix the toner on the sheet 8 on the full-color image.

  The heating roller 23 includes a heat source 37 such as a halogen heater inside the roller, and heats the fixing belt 24 from the back side by heat generated by the heat roller. A temperature sensor 39 a is disposed below the heating roller 23. The temperature sensor 39a sends a signal that detects the surface temperature of the portion where the fixing belt 24 is wound around the heating roller 23 in a non-contact manner to a temperature control unit (not shown). Based on the signal sent from the temperature sensor 39a, the temperature control unit controls ON / OFF the power supply to the heat source 37 of the heating roller 23 so that the surface temperature of the fixing belt 24 is maintained at a preset fixing temperature. To do. Further, in the illustrated fixing device 11, the fixing belt 24 is sufficiently stored with respect to the heating roller 23 serving as a heating unit to sufficiently store heat.

  The pressure roller 25 also includes a heat source 38 such as a halogen heater inside the roller, and the pressure roller 25 is heated by the heat generated thereby. A temperature sensor 39b is disposed below the pressure roller 25. The temperature sensor 39b sends a signal that detects the surface temperature of the pressure roller 25 in a non-contact manner to a temperature control unit (not shown). Based on the signal sent from the temperature sensor 39b, the temperature control unit turns on / off the power supply to the heat source 38 of the pressure roller 25 so as to maintain a preset fixing temperature of the surface temperature of the pressure roller 25. Turn OFF control.

  The fixing belt 24 is provided with a fixing belt side oil application device 28 and a take-up web cleaner 27 for sheet peeling. The winding web cleaner 27 fixes the full-color image on the paper 8 with the fixing nip surface 41 and then wipes and cleans off the residue of the full-color image that cannot be fixed on the fixing belt 24. The fixing belt side oil application device 28 includes an oil discharge pipe 30, a felt 31, a supply roller 32, a regulating blade 33, an application roller 34, and an oil tray 35. In an oil storage tank (not shown), sheet peeling promoting oil is stored. The sheet peeling accelerating oil is sent from the oil storage tank into the oil discharge pipe 30 and impregnated in the felt 31 in contact with the oil discharge pipe 30.

  The supply roller 32 is rotationally driven by a driving unit (not shown) while being in contact with the felt 31, the regulation blade 33, and the application roller 34, whereby the sheet peeling promotion oil moves in the order of the supply roller 32 and the application roller 34. The regulation blade 33 can adjust the paper peeling promoting oil supply to the supply roller 32. Further, the regulation blade 33 collects excess paper peeling acceleration oil. Excess paper peeling promoting oil is collected in the oil tray 35 through the regulation blade 33. The sheet peeling accelerating oil is applied to the fixing belt 24 by the application roller 34 and the fixing belt 24 being rotationally driven by a driving unit (not shown) while being in contact with each other. The fixing belt 24 is prepared for the fixing operation in a state where the sheet peeling accelerating oil is sufficiently applied, so that the sheet 8 on which the full color image is transferred is conveyed to the fixing device 11 and passes through the fixing device 11. The paper 8 can be transported without the paper 8 being attracted to the fixing belt 24.

  When the paper 8 passes through the fixing device 11, the paper 8 absorbs the paper peeling promoting oil applied to the fixing belt 24. The sheet peeling accelerating oil applied to the fixing belt 24 is reduced because the sheet 8 absorbs moisture after the fixing operation. Therefore, the fixing belt 24 is driven to rotate, and the sheet peeling acceleration oil is applied from the fixing belt side oil applying device 28 to the portion where the fixing belt side oil application amount is reduced to prepare for the next fixing operation. .

  The pressure roller 25 is provided with a pressure roller-side oil application device 29 and a surplus oil collecting and conveying tube 36. One end of the surplus oil collecting and conveying tube 36 is disposed on the bottom side of the oil receiving tray 35, and the other end is disposed on the upper side of the pressure roller side oil applying device 29. The surplus oil collected by the oil tray 35 flows into the pressure roller side oil application device 29 through the surplus oil collection transport tube 36 and is collected. The sheet peeling acceleration oil collected by the pressure roller side oil application device 29 is applied to the pressure roller 25 through the oil pad 40 in the pressure roller side oil application device 29.

  Next, the conveyance operation of the sheet conveyance control device for setting the sheet conveyance interval according to the sheet type, the thickness of the sheet 8, and the environmental temperature according to the present invention will be described with reference to the flowcharts of FIGS.

  FIG. 3 is a flowchart of the sheet conveyance interval setting process according to the present invention. In the paper conveyance interval setting process, first, in step S1, it is checked whether or not the paper 8 has been fed from the paper supply device. If the paper 8 has been fed, in step S2, data such as the type of the paper 8, the paper thickness, the internal temperature / humidity, the temperature / humidity of the fed paper stacking unit, and the fixing set temperature are prepared as data preparation for the paper. Prepare.

In step S3, when the consumption of the peeling acceleration oil applied to the fixing belt 24 in the fixing operation is large from the data prepared in step S2, the sheet conveyance interval is set to N on the basis of one rotation of the fixing belt in order to secure the peeling acceleration oil supply time. Set to lap. When the consumption of the peeling accelerating oil is small, this N lap becomes zero. N laps can be set up to the nth decimal place. n can be set as an integer of 1, 2, 3, 4. If the sheet conveyance interval is set to N in step S3, it is checked in step S4 whether the sheet 8 fed from the current sheet stacking unit is the first sheet. At this time, if it is not the first sheet, the sheet conveyance interval time T is calculated in step S5. In step S5, the time T is calculated by (fixing belt length L1 + margin L2) ÷ linear velocity × fixing belt N circumference, and then the paper conveyance interval time T is set in the information of the paper 8 fed in step S6.

  On the other hand, if it is determined in step S4 that the first sheet 8 fed from the sheet stacking unit is the first sheet, the sheet conveyance interval N is set to 0 in step S7, and the sheet 8 fed in step S8 is set. In this information, the sheet conveyance interval time T is set to 0.

  FIG. 4 is a diagram showing a flowchart of the paper stop point conveyance process according to the present invention. In the paper stop point conveyance process, it is checked in step S9 whether the leading end position of the paper 8 is at the paper stop point 16b. If the leading edge of the paper 8 is at the paper stop point 16b in step S9, it is checked in step S10 whether an image has been transferred to the intermediate transfer belt 10. If the image is not transferred to the intermediate transfer belt 10 in step S10, the rotation of the timing roller pair 15 and the rotation of the registration roller pair 13 are stopped in step S11, and the sheet 8 is stopped and waited at the sheet stop point 16a. .

  If the image is transferred to the intermediate transfer belt 10 in step S10, it is checked in step S12 whether or not the conveyance timing for transferring the image to the paper 8 is reached. In step S12, in the case of the conveyance timing for transferring the image to the paper 8, the paper 8 is conveyed to the paper transfer unit 9 by rotating the timing roller pair 15 and the registration roller pair 13 in step S13.

  If the leading end position of the paper 8 is not at the paper stop point 16b in step S9 or if it is not in the transport timing for transferring the image to the paper 8 in step S12, the paper stop point transport process is temporarily ended.

  FIG. 5 is a diagram showing a flowchart of an operation for setting a paper conveyance interval in the paper conveyance processing according to the present invention. In the paper transport process, the T time of the information on the paper 8 is checked in step S14. If the T time of the information on the paper 8 is other than 0 in step S14, the elapsed time since the previous image forming operation instruction is checked in step S15.

  In step S15, if the elapsed time from the previous image forming operation instruction has passed for more than T hours, the image forming operation of the sheet 8 is instructed to the image forming units 1a to 1d in step S16. If the T time of the information on the paper 8 is 0 in step S14, the image forming operation of the paper 8 is instructed to the image forming units 1a to 1d in step S16.

  In step S15, if the elapsed time from the previous image forming operation instruction is less than T time, the paper conveyance process is once ended.

As described above, the present embodiment has the following advantages.
(1) The paper type and paper when feeding paper by providing means for detecting the paper type, paper thickness, machine environment temperature and humidity, or the temperature and humidity of the paper stacking unit. Depending on the thickness of the machine or the environment of the machine and the paper feed unit, setting the transport interval and increasing the paper transport interval to the fixing unit makes it possible to print highly hygroscopic paper, such as envelopes, In printing in such an environment, paper jam can be prevented by stably supplying the sheet peeling oil from the oil application mechanism to the fixing belt without changing the oil application mechanism of the fixing device.
(2) The paper conveyance control device sets the conveyance interval to be equal to or longer than one rotation of the fixing belt so that the oil can be uniformly applied regardless of the portion of the fixing belt where the oil application amount is insufficient. It is effective.
(3) The sheet conveyance control device is provided with means for setting the continuous conveyance number N and the conveyance interval of the sheet after the continuous conveyance so that the conveyance is performed with a conveyance interval of the sheet conveyance after the N sheets are continuously printed. By repeating the above and limiting the number of fixing sheets per time, the execution speed can be reduced.

  The present invention has been described above by the preferred embodiments of the present invention. While the invention has been described with reference to specific embodiments, various modifications and changes may be made to the embodiments without departing from the broad spirit and scope of the invention as defined in the claims. Obviously you can. In other words, the present invention should not be construed as being limited by the details of the specific examples and the accompanying drawings.

1 is a schematic diagram of a four-color full-color image forming apparatus using a transport sheet standby type sheet transport apparatus according to an embodiment of the present invention. 1 is a configuration diagram of a fixing device using a fixing belt system in an embodiment of the present invention. FIG. FIG. 6 is a flowchart illustrating a sheet conveyance interval setting process according to the present invention. FIG. 6 is a flowchart of a sheet stop point conveyance process according to the present invention. FIG. 6 is a diagram illustrating a flowchart of a sheet conveyance process for making a sheet conveyance interval according to the present invention.

Explanation of symbols

1a to 1d Image forming unit 2a to 2d Photosensitive drum 3a to 3d Drum charger 4a to 4d Exposure device 5a to 5d Developer 6a to 6d Transfer device 7a to 7d Cleaning device 8 Paper 9 Paper transfer device 10 Intermediate transfer belt 11 Fixing device DESCRIPTION OF SYMBOLS 12 Belt cleaning mechanism 13 Registration roller pair 14a-14g Conveyance roller pair 15 Timing roller pair 16a-16c Paper stop point 17 Paper supply device 18 Conveyance belt 19a-19b Paper stacking part 20a-20b Paper feed part 21a-21c Temperature / humidity sensor 22 Fixing roller 23 Heating roller 24 Fixing belt 25 Pressure roller 26 Tension roller 27 Winding web cleaner 28 Fixing belt side oil application device 29 Pressure roller side oil application device 30 Oil discharge pipe 31 Felt 32 Supply roller 33 Control blade 34 application roller 35 oil pan 36 excess oil collecting the transfer tube 37 heat source 38 heat sources 39a, 39b temperature sensor 40 Oil pad 41 fixing nip plane

Claims (7)

The paper transported from the paper feed unit is appropriately stopped on the transport path, and the paper is transported to the transfer unit according to the toner image latent on the intermediate transfer belt, and then the paper onto which the toner image has been transferred is transported to the fixing device. A transport control unit that fixes and discharges a toner image on a sheet with the fixing unit;
The fixing device includes an endless fixing belt that is looped between a plurality of belt conveyance rollers and rotates, and a portion that is wound around the fixing roller that is one of the plurality of belt conveyance rollers on the fixing belt. The fixing belt and the pressure roller are provided with an oil application mechanism for supplying paper peeling oil, and the oil application mechanism provided for the fixing belt has an oil blade for adjusting oil supply. Provided ,
In order to realize a stable supply of paper peeling oil, the transport control unit transports the paper to the fixing device at a transport interval of one rotation or more of the fixing belt set according to the type of the paper. An image forming apparatus. The image forming apparatus according to claim 1.
2. The image forming apparatus according to claim 1, wherein the conveyance interval is a conveyance interval based on a length obtained by adding a margin length to the length of one rotation of the fixing belt and a sheet conveyance speed. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the conveyance control unit sets a conveyance interval equal to or more than one rotation of the fixing belt according to a thickness of a sheet to be conveyed. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the conveyance control unit sets a conveyance interval equal to or more than one rotation of the fixing belt according to the temperature and humidity of the sheet feeding unit in addition to the type of the sheet. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the conveyance control unit sets a conveyance interval equal to or greater than one rotation of the fixing belt according to an in-machine temperature and humidity in addition to the type of the sheet. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the conveyance control unit sets a conveyance interval equal to or more than one rotation of the fixing belt according to a set fixing temperature in addition to the type of the sheet. The image forming apparatus according to claim 1.
The conveyance control unit conveys a conveyance interval after conveying the first sheet as a conveyance interval equal to or more than one rotation of the fixing belt when continuously conveying sheets conveyed with a conveyance interval. An image forming apparatus.

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