CN104932235A - Image forming device - Google Patents

Abstract

The invention provides an image forming device which can reduce the power consumption in photographic fixing treatment and prevent crimp. The image forming device comprises a photographic fixing treatment part which comprises a heating part receiving the heating of a heat source and a pressurizing part, wherein the heating part and the pressurizing part form a clamping and pressing part together. Through the intelligent photographic fixing control for the heat source, when the photographic fixing for toner images requires less heat, the photographic fixing temperature of photographic fixing treatment is set lower than the photographic fixing temperature set when the required heat is much, and the temperature of the heating part is made to be the temperature higher than the photographic fixing temperature before sheets arrive at the clamping and pressing part. Then, for a first sheet and a second sheet passing through the clamping and pressing part successively, when the photographic fixing temperature of the second sheet is higher than that of the first sheet, the temperature difference limit control of images is performed, so that the temperature difference of the heating part and the pressurizing part generated when the first sheet passes through the clamping and pressing part does not exceed the preset temperature difference upper limit.

Description

Image processing system

Technical field

The present invention relates to a kind of image processing system carrying out making to be transferred to through heating the process fixing on paper of toner image on paper, say in further detail, relate to the temperature reducing fixing process as much as possible and the image processing system that can reduce power consumption.

Background technology

Printer, duplicating machine etc. have fixing handling part based on the general image processing system of electrofax mode, and this fixing handling part carries out for making to be transferred to the fixing process of toner image on paper.Fixing handling part by heating the paper carrying toner image while pressurize carry out fixing process.The paper that have passed fixing handling part can occur curling and bending.There occurs curling paper and become the main cause that paperboard occurs in conveying afterwards, and, can obstacle be there is time sometimes stacking on carton.In addition, when being bound into book form by multipage binding papers, bookbinding quality also may be caused to decline.Therefore, the amount of crimp alleviating paper generation is as much as possible expected.

So, in order to alleviate the amount of crimp of paper, control the heating-up temperature to paper in fixing handling part.Such as, a kind of image processing system is described in patent documentation 1, its first surface and the back side thereof that is second two-sided on carry out continuously in the duplex printing of image formation, when carrying out the fixing process of first surface, to the position becoming the front end of throughput direction of second, carry out fixing process with the temperature lower than other positions.Thereby, it is possible to alleviate the amount of crimp of the front of second, and reduce the bad problem of conveying when forming image on the second surface.

In addition, in patent documentation 2, describe a kind of image processing system, it is on the Width orthogonal with the throughput direction of paper, carries out fixing process with different temperature to two ends and central authorities.Specifically, when forming image on the first face, with the temperature lower than central authorities, fixing process is carried out to two ends.Further, when forming image on the second surface, with the temperature higher than centralised temperature and higher than the fixing treatment temperature of the end when first surface forms image, fixing process is carried out to two ends.Thereby, it is possible to suppress curling generation, thus prevent paperboard.

Patent documentation 1: Japanese Unexamined Patent Publication 10-10915 publication

Patent documentation 2: Japanese Unexamined Patent Publication 2012-32654 publication

But occurred a kind of image processing system in recent years, it is in order to reduce power consumption, carry out the temperature of fixing handling part to suppress for the lower fixing control of intelligence according to the image that will be formed.Specifically, the toner adhesion amount forming the toner image of image is fewer, and intelligent fixing control more carries out fixing process with low temperature.By the fixing control of intelligence, by computer heating control in Min., thus power consumption can be reduced.For the image that will be formed, the toner adhesion amount of toner image can judge according to the information such as any in concentration, text width, word size, colour and black and white.

In the image processing system carrying out the fixing control of such intelligence, the first paper carrying out fixing process with low temperature and carry out fixing process with high temperature the second paper successively by fixing handling part when, fixing handling part must be made to be set to high temperature before the second paper arrives fixing handling part.So, in this case, even if the first paper is in the process by fixing handling part, fixing handling part also must be made to heat up.But, owing to starting to heat up in the process of the first paper by fixing handling part, cause existence first paper that curling problem easily occurs.Because above-mentioned any prior art does not all consider the fixing control of such intelligence, so the problem produced in the fixing control of such intelligence all can not be solved.

Summary of the invention

The present invention makes to solve for the purpose of the problem existing for above-mentioned prior art.In other words, problem of the present invention is to provide a kind of power consumption when can reduce fixing process, and suppresses the image processing system of curling generation.

Have to solve the image processing system of the present invention made for the purpose of this problem: image forming part, it forms toner image, by being transferred on sheet material by this toner image, sheet material forms toner image; Fixing handling part, it has the heating part of the heating accepting thermal source and jointly forms the pressurization part of clamp-press part with heating part, makes the sheet material transferred with toner image carry out fixing process by clamp-press part; Apparatus control portion, each several part of its control device and carry out image formation; The feature of this image processing system is to have: heated side temperature efferent, and it exports and represents the heated side temperature value of heating part in the temperature of the position of clamp-press part; Pressure side temperature efferent, it exports and represents the pressure side temperature value of pressurization part in the temperature of the position of clamp-press part; Utilize image forming part be transferred to the fixing required heat of toner image on sheet material few time, with fixing required heat multidate ratio, sheet material is set as lower by the target of heated side temperature value during clamp-press part and fixing temperature by apparatus control portion; Apparatus control portion carries out the fixing control of intelligence of the heating of control of heat source, makes heated side temperature value before sheet material arrives clamp-press part become the temperature more than to the fixing temperature set by this sheet material; And, for the second sheet material continued through after the first sheet material of clamp-press part and the first sheet material, when fixing temperature higher than the first sheet material of the fixing temperature of the second sheet material, apparatus control portion performs the temperature difference restriction forming image and controls, and makes the first sheet material be no more than by the difference of heated side temperature value during clamp-press part and pressure side temperature value and temperature difference the ceiling temperature preset poor.

Image processing system of the present invention utilizes intelligent fixing control to carry out the heating of thermal source with Min., reduces the power consumption of fixing handling part thus.When carrying out intelligent fixing control, during fixing temperature higher than the first sheet material of the fixing temperature of the second sheet material, during the first sheet material is by clamp-press part, the heating part in clamp-press part and the temperature difference of pressurization part become greatly, may occur more serious curling by the first sheet material.So the temperature difference restriction that the mode utilizing to make temperature difference be no more than ceiling temperature difference carries out image formation controls, and can reduce by the first sheet material and curling degree occurs and suppresses paperboard.

And, in above-mentioned image processing system, preferred heated side temperature efferent detects the sensor of heating part in the temperature of the position of clamp-press part, pressure side temperature efferent detects the sensor of pressurization part in the temperature of the position of clamp-press part, apparatus control portion is in temperature difference restriction controls, when temperature difference reaches the heating stopping temperature difference being redefined for the following value of ceiling temperature difference, stop the heating of thermal source.This is due to can be poor based on the actual temperature of the heating part of clamp-press part and pressurization part, reliably makes temperature difference be no more than ceiling temperature difference.There is curling degree thereby, it is possible to alleviate the first sheet material and suppress paperboard.

And in above-mentioned image processing system, preferred heated side temperature efferent and pressure side temperature efferent are apparatus control portion; Apparatus control portion is before utilizing image forming part to start to form the toner image of the first sheet material, and heated side temperature value when making heated side temperature value rise to the fixing temperature of the second sheet material to making the first sheet material utilize thermal source to heat by clamp-press part and pressure side temperature value emulate; Based on by emulating the heated side temperature value obtained and pressure side temperature value, the guess value of the temperature difference when rear end obtaining the first sheet material arrives clamp-press part infers temperature difference; When the supposition temperature difference obtained exceedes ceiling temperature difference, determine that performing temperature difference restriction controls; When determining that performing temperature difference restriction controls, performing temperature difference restriction when the image of formation first sheet material and controlling.This limits control owing to carrying out temperature difference when inferring that the actual temperature difference of heating part and the pressurization part clamp-press part exceedes ceiling temperature difference by emulation, can by temperature difference suppression below ceiling temperature difference.There is curling degree thereby, it is possible to alleviate the first sheet material and suppress paperboard.

And in above-mentioned image processing system, apparatus control portion, in simulations based on calculated heated side temperature value and pressure side temperature value, is obtained and is namely exceeded opportunity the opportunity that the first sheet material exceedes ceiling temperature difference by the temperature difference during clamp-press part; In temperature difference restriction controls, obtained by emulation exceed opportunity before stop the heating of thermal source; After the rear end of the first sheet material have passed clamp-press part, the heating of the thermal source stopped can being made to restart.This curling degree occurs owing to can alleviate the first sheet material and suppresses paperboard this point to change.

And in above-mentioned image processing system, apparatus control portion limits the heating of thermal source in temperature difference restriction controls, make the rising degree of heated side temperature value in temperature difference restriction controls slower than the rising degree in emulation.This curling degree occurs owing to can alleviate the first sheet material and suppresses paperboard this point to change.

And, in above-mentioned image processing system, preferred embodiment control part is in temperature difference restriction controls, and before the front end of the first sheet material arrives image forming part and the rear end of the first sheet material is slower than the transporting velocity of the first sheet material in emulation by the transporting velocity that the front end of the first sheet material after image forming part arrives first sheet material of at least one party during clamp-press part.This is higher owing to can maintain formed picture quality, and can alleviate the first sheet material and curling degree occurs and suppresses paperboard.In addition, " slow down transporting velocity " also comprises the conveying of the first sheet material is temporarily stopped.

And in above-mentioned image processing system, apparatus control portion is in temperature difference restriction controls, and the rising that the rising that can make to utilize the heating of thermal source to make heated side temperature value start to rise is later than in emulation the opportunity of starting starts opportunity.This curling degree occurs owing to can alleviate the first sheet material and suppresses paperboard this point to change.

And, in above-mentioned image processing system, preferred embodiment control part temperature difference restriction control in, make the heating utilizing thermal source make heated side temperature value start rise rising start opportunity early than emulation in rising start opportunity.This is the degree owing to temperature difference can be suppressed to alleviate below ceiling temperature difference the first curl of sheet, and it is higher to maintain throughput rate.

And in above-mentioned image processing system, have: turning part, it makes the pros and cons of the sheet material being formed with image by clamp-press part on the first face overturn; Two-sided carrying path, the sheet material that have passed turning part is transported to than the position of image forming part near upstream in order to the back side at this first surface that is second form image by again; When preferably carrying out successively implementing fixing process to first surface in the duplex printing of image formation on the first surface of the first sheet material and second, apparatus control portion is carried out temperature difference restriction and is controlled.For sheet material, after utilizing turning part to overturn pros and cons, the rear end when image of first surface is formed becomes the front end during image formation of second.In addition, when forming the image of first surface, the rear end side because of sheet material sheet material by clamp-press part easily occurs serious curling.That is, front position when being formed by suppressing the image of second curling, paperboard when can prevent the image of second from being formed.In addition, when only forming image on the first face and when forming image on the second surface, because do not need afterwards to overturn pros and cons, even if therefore more or less there occurs curling, the frequency that paperboard occurs is also low.

And in above-mentioned image processing system, have: turning part, it makes the pros and cons of the sheet material being formed with image by clamp-press part on the first face overturn; Two-sided carrying path, the sheet material that have passed turning part is transported to than the position of image forming part near upstream in order to the back side at this first surface that is second form image by again; Apparatus control portion can at the fixing temperature of the fixing temperature of the second sheet material lower than the first sheet material, and by the fixing temperature of the fixing temperature of the sheet material of clamp-press part lower than the first sheet material before the first sheet material, and the first sheet material be form the sheet material of image on a first side thereof, the second sheet material is when forming the sheet material of image on a second side by two-sided carrying path, the image carrying out the second sheet material before the image of the first sheet material is formed is formed, and the restriction of execution temperature difference controls when the image of the second sheet material is formed.This curling degree occurs owing to can alleviate the first sheet material and suppresses paperboard this point to change.

And, in above-mentioned image processing system, there is storage part, this storage part stores the thickness of the first sheet material, the first sheet material length in the conveying direction, the first sheet material are shown by the relation of at least one condition in speed during clamp-press part and ceiling temperature difference and ceiling temperature difference, apparatus control portion can, in temperature difference restriction controls, use the value showing to determine with reference to ceiling temperature difference poor as ceiling temperature.This is due to based on these conditions, even if use different values poor as ceiling temperature, curling generation this point also can be suppressed to change.

According to the present invention, a kind of power consumption that can reduce fixing process can be provided, and suppress the image processing system of curling generation.

Accompanying drawing explanation

Fig. 1 is the figure representing image processing system.

Fig. 2 is the figure of the fixing handling part representing image processing system.

Fig. 3 is the schematic diagram of the control structure of image processing system.

Fig. 4 is the figure for illustration of the fixing control of intelligence.

Fig. 5 is the curve map representing the temperature making paper by fixing handling part during fixing clamp-press part under low temperature mode.

Fig. 6 is the curve map of temperature of fixing handling part when representing the fixing clamp-press part in making paper pass through to heat up.

Fig. 7 is the curve map of the temperature difference restriction control for illustration of first method.

Fig. 8 is the curve map of the temperature difference restriction control for illustration of second method.

Fig. 9 is the curve map of the temperature difference restriction control for illustration of Third Way.

Figure 10 is the curve map of the temperature difference restriction control for illustration of fourth way.

Figure 11 is the curve map of the temperature difference restriction control for illustration of the 5th mode.

Figure 12 is the curve map of the temperature difference restriction control for illustration of the 6th mode.

Description of reference numerals

1 image processing system, 4CPU, 10 image forming parts, 70 fixing handling parts, 71 backer rolls, 72 fixing rollers, 73 warm-up mills, 74 heating arrangements, 75 fixing bands, the fixing clamp-press part of N2, P paper.

Embodiment

Below, be described with reference to accompanying drawing embodiment the present invention specialized in detail.

[first method]

Fig. 1 represents the general configuration of the image processing system 1 of the manner.Image processing system 1 is the color printer of the so-called tandem with intermediate transfer belt 30.Intermediate transfer belt 30 is the ring-shaped tape members with electric conductivity, its both ends in this Fig. 1 by roller 31,32 supportings.When image is formed, in Fig. 1, the roller 31 on right side is according to carrying out shown in arrow in figure being rotated counterclockwise driving.Thus, in intermediate transfer belt 30 and Fig. 1, the roller 32 in left side carries out driven rotation respectively to direction shown in arrow in figure.

In intermediate transfer belt 30 by Fig. 1 in the outer peripheral face of part that supports of the roller 31 on right side be provided with secondary transfer roller 40.Secondary transfer roller 40 presses to intermediate transfer belt 30 along the direction (left-hand in Fig. 1) vertical with its axle and contacts with it.The part contacted with secondary transfer roller 40 at intermediate transfer belt 30 is formed with the secondary transfer printing clamp-press part N1 be transferred to by the toner image on intermediate transfer belt 30 on paper P.Secondary transfer roller 40 utilizes when image is formed and to crimp with the intermediate transfer belt 30 rotated and the friction force that produces carries out driven rotation.

Further, in intermediate transfer belt 30 by Fig. 1 in the outer peripheral face of part that supports of the roller 32 in left side be provided with band cleaning device 41.With cleaning device 41 for reclaiming the toner be attached on intermediate transfer belt 30 surface.That is, be with cleaning device 41 for being recovered in secondary transfer printing clamp-press part N1 the transfer residual toner etc. be not transferred on paper P.

Bottom in Fig. 1 of intermediate transfer belt 30, is configured with the image forming part 10Y of Huang (Y), pinkish red (M), blue or green (C), black (K) colors, 10M, 10C, 10K from left to right successively.Image forming part 10Y, 10M, 10C, 10K are toner image for the formation of corresponding look and the device be transferred on intermediate transfer belt 30, and image forming part 10Y, the structure of 10M, 10C, 10K is all identical.Therefore, in FIG, with image forming part 10Y for representative has marked Reference numeral.

Image forming part 10Y, Charging system 12, exposure device 13, developing apparatus 14, primary transfer roller 15 that 10M, 10C, 10K have cylindric electrostatic latent image supporting body and photoreceptor 11 and be configured in around photoreceptor 11.Charging system 12 is for making the uniformly charged of photoreceptor 11.Exposure device 13 forms electrostatic latent image for irradiating the laser based on the view data of corresponding look to the surface of photoreceptor 11.Developing apparatus 14 is for supplying the surface of the toner of storage to photoreceptor 11.

Primary transfer roller 15 is configured in the position relative with photoreceptor 11 across intermediate transfer belt 30.Primary transfer roller 15 presses to intermediate transfer belt 30 along the direction (in Fig. 1 lower direction) vertical with its axle and contacts with it.Be transferred to the primary transfer clamp-press part on intermediate transfer belt 30 at each several part that intermediate transfer belt 30 contacts with photoreceptor 11 toner image be formed on the photoreceptor 11 making colors because of this crimping.

It should be noted that, the image forming part 10Y of the manner, 10M, 10C, 10K be utilize developing apparatus 14 reclaim non-transfer toner on photoreceptor 11 without cleaning type image forming part.But, can have for reclaiming the non-transfer photoreceptor cleaning device to the toner on intermediate transfer belt 30 from photoreceptor 11.As photoreceptor cleaning device, enumerate tabular and the device that contacts with the outer peripheral face of photoreceptor 11 of one end.Or also can use other cleaning members, such as stationary brush, rotating brush, roller or the cleaning member formed by the multiple component combinations in these parts.

Further, be configured with the toner bottle 20Y being accommodated with each colour toners above in Fig. 1 of intermediate transfer belt 30,20M, 20C, 20K, be accommodated in the developing apparatus 14 suitably supply of each colour toners respectively to colors of these toner bottles.

In the bottom of image processing system 1, paper feeding cassette 51 is installed.Carrying path 50 is provided with upward from the right side Fig. 1 of paper feeding cassette 51.The paper P being accommodated in paper feeding cassette 51 by loading utilizes paper feed roller 52 to export to carrying path 50 page by page from the paper of its topmost.

The carrying path 50 of the paper P exported from paper feeding cassette 51 is configured with a pair aligning dancer rools 53, secondary transfer printing clamp-press part N1, fixing clamp-press part N2 and exit roller 54 successively.Be provided with in the further downstream side of carrying path 50 for discharging the paper delivery portion 55 completing the paper P that image is formed.Aim at dancer rools 53 for finely tuning the opportunity exported to secondary transfer printing clamp-press part N1 by paper P.Fixing clamp-press part N2, for carrying out making being transferred to the fixing fixing process of toner image on paper P, is formed by fixing handling part 70.

The fixing handling part 70 of the manner is described with reference to Fig. 2.As shown in Figure 2, fixing handling part 70 is made up of backer roll 71, fixing roller 72, warm-up mill 73, heating arrangement 74, fixing band 75, temperature sensor 76, wherein, the fixing roller 72 except backer roll 71, warm-up mill 73, heating arrangement 74, fixing band 75 and temperature sensor 76 are configured in the side, face of the carrying toner of paper P.Fixing handling part 70 carries out the fixing process for making toner image fixing to the paper P be transferred on carrying path 50.

As shown in Figure 2, fixing roller 72 with warm-up mill 73 have been wrapping with fixing band 75.Heating arrangement 74 is the thermals source being arranged on warm-up mill 73 inside.Temperature sensor 76 is for detecting the temperature of warm-up mill 73.Therefore, fixing roller 72, warm-up mill 73, heating arrangement 74, fixing band 75, temperature sensor 76 are structure members of heated side.On the other hand, backer roll 71 is configured in the position relative with fixing roller 72 across fixing band 75.Backer roll 71 is crimped on the outer peripheral face of fixing band 75, is formed with fixing clamp-press part N2 in this contact portion.Therefore, backer roll 71 is structure members of pressure side.

Fixing roller 72, when performing fixing process, drives shown in arrow counterclockwise according in Fig. 2.By the rotation of this fixing roller 72, backer roll 71, warm-up mill 73 and fixing band 75 carry out driven rotation separately.Warm-up mill 73 is heated by heating arrangement 74, to make temperature detected by temperature sensor 76 for set point of temperature.Thus, the temperature of fixing band 75, fixing roller 72 also raises.Paper P is by pressurized by heating one side on one side during fixing clamp-press part N2.Through this fixing process, toner image is fixed on paper P.

As shown in Figure 1, the image processing system 1 of the manner has two-sided carrying path 60.Two-sided carrying path 60 is for again carrying the paper P that once have passed carrying path 50 to carrying path 50.Thus, image processing system 1 can paper P two-sided on form image.It should be noted that, the sensor be provided with the arrival for detecting paper P in each position of carrying path 50, two-sided carrying path 60, passing through.

Fig. 2 roughly represents the control structure of image processing system 1.In order to carry out the control of each several part, image processing system 1 has engine part 2 and control part 3.Engine part 2 has the CPU4 carrying out overall control treatment and the nonvolatile memory 5 being attached to main body.

Nonvolatile memory 5 stores each value such as rotational speed, the rotational speed of each photoreceptor 11, the transporting velocity of paper P of such as roller 31, the fixing band 75 also storing fixing clamp-press part N2 and backer roll 71 by the higher limit of temperature difference of allowing and the poor TDlim of ceiling temperature etc.About ceiling temperature difference TDlim, will describe in detail below.

CPU4, based on the value be stored in nonvolatile memory 5, controls each several part of image processing system 1, performs the task that image is formed thus.In other words, when executing the task, the rotation of photoreceptor 11, each roller that roller 31 is relevant to the conveying of paper P etc. is controlled.In addition, also the heating of heating arrangement 74 is controlled etc., to guarantee that the detected temperatures of temperature sensor 76 is the set point of temperature for carrying out fixing process.In addition, CPU4 utilizes the sensor being arranged on each position of carrying path 50 and two-sided carrying path 60 to obtain the physical location of the paper P in conveying.Therefore, CPU4, by comparing the target location of the paper P set through controlling conveying and the physical location obtained by the sensor of carrying path 50 grade, can detect whether paper P paperboard etc. occurs.In addition, the CPU4 of the manner forms the information of task according to the image be transfused to, and by the emulation described in detail below, can calculate the temperature of fixing band 75 in fixing clamp-press part N2 position and backer roll 71 respectively.

Engine part 2 not only controls the various loads 6 of image processing system 1, and carries out write or the reading of the nonvolatile memory 7 being attached to each unit.Various load 6 such as comprises toner bottle, image-generating unit etc.In the nonvolatile memory 7 being attached to each unit, the storer being such as attached to toner bottle stores Toner allowance etc., and the storer being attached to image-generating unit stores number of print pages etc.

Control part 3 is connected with outside computing machine etc. and accepts indicative input.Such as, by forming instruction from computing machine acceptance pattern picture, in image processing system 1, synthetic image forms task.In addition, by various information such as engine part 2 and control part 3 exchange spot count values (De ッ ト カ ウ ン タ ー value).

Then, the common image of the image processing system 1 of simple declaration the manner forms an example of action.The following description is an example of the image formation action under the color mode of the toner formation coloured image using four colors on the paper P being accommodated in paper feeding cassette 51.When forming coloured image, the photoreceptor 11 of intermediate transfer belt 30 and colors to rotate according to direction shown in arrow in Fig. 1 with the circumferential speed of regulation respectively and carries out.

Then, the outer peripheral face of photoreceptor 11 utilizes Charging system 12 charged roughly equably.Utilize exposure device 13, the light corresponding with view data is irradiated to the outer peripheral face of charged photoreceptor 11 and forms electrostatic latent image.Utilize the beginning starting to be image formation of the exposure of this exposure device 13.Then, electrostatic latent image is developed device 14 and develops, and photoreceptor 11 forms toner image.The primary transfer clamp-press part that assorted toner image is formed in the crimping by primary transfer roller 15 is transferred (primary transferred) on intermediate transfer belt 30.Thus, the toner image of overlapping yellow (Y), pinkish red (M), blue or green (C), black (K) successively on the intermediary transfer belt 30.Then, utilize the rotation of intermediate transfer belt 30, the toner image of four overlapping colors is transported to secondary transfer printing clamp-press part N1.

On the other hand, the paper P being accommodated in paper feeding cassette 51 is extracted to carrying path 50 page by page from topmost.The paper P be drawn out of is transported to secondary transfer printing clamp-press part N1 along carrying path 50.Utilize the opportunity that paper P enters secondary transfer printing clamp-press part N1 and aim at dancer rools 53 and finely tune, make this opportunity and the toner image on intermediate transfer belt 30 enter opportunity of secondary transfer printing clamp-press part N1 consistent.Thus, at secondary transfer printing clamp-press part N1, the toner image of four overlapping colors is transferred (secondary transfer printing) on paper P.

Paper P transferred with toner image is carried to the downstream of carrying path 50 further.That is, after being implemented the fixing process of toner image, exit roller 54 is utilized to be discharged to paper delivery portion 55 through fixing clamp-press part N2 at paper P.It should be noted that, after have passed secondary transfer printing clamp-press part N1, residual transfer residual toner on the intermediary transfer belt 30 is also reclaimed by band cleaning device 41, and thus, transfer residual toner is removed from intermediate transfer belt 30.

In addition, when carrying out duplex printing to paper P, the paper P being formed with image by carrying path 50 on the first face utilizes exit roller 54 to carry out pros and cons upset, while be transported to two-sided carrying path 60.That is, in the image processing system 1 of the manner, exit roller 54 doubles as the turning part that the pros and cons of paper P is overturn.Then, the paper P that have passed two-sided carrying path 60 is transported to carrying path 50 again.Thereby, it is possible to form image on contrary with first surface second of paper P.Be formed with the rear of the paper P of image on two-sided in this way to discharge to exit roller 55.

At this, image processing system 1 can carry out making the temperature of fixing handling part 70 be set to the fixing control of intelligence of different temperatures accordingly with the image that will be formed.Specifically, in the fixing control of the intelligence of the manner, accordingly the heating of heating arrangement 74 is controlled with the toner adhesion amount of the toner image of the image that will be formed.That is, carrying the paper P of the few toner image of toner adhesion amount by fixing clamp-press part N2 time control refrigerating/heating apparatus 74, making heating-up temperature lower than carrying the paper P of the many toner images of toner adhesion amount by heating-up temperature during fixing clamp-press part N2.With toner adhesion amount multidate ratio when reason is that toner adhesion amount is few, low temperature can be utilized to heat toner image is fixed on paper P.

In addition, when utilizing intelligent fixing control to carry out fixing process to the paper P carrying the few toner image of toner adhesion amount, power consumption can be suppressed.It should be noted that, when carrying out the fixing process of the many coloured images of toner adhesion amount in the image processing system 1 of the manner, the normal mode being set to the fixing temperature T1 preset with the heating-up temperature of the paper P making fixing clamp-press part N2 carries out fixing process.On the other hand, when carrying out the fixing process of the few black white image of toner adhesion amount, carry out fixing process with the low temperature mode making the heating-up temperature of paper P be set to the fixing temperature T2 lower than the fixing temperature T1 of normal mode.That is, image processing system 1 switches the warm mode transfer formula of fixing handling part 70 and carries out fixing process between the different normal mode of temperature and low temperature mode.

It should be noted that, think in the manner, toner adhesion amount when forming coloured image compared with when forming black white image in toner image is many and carry out the switching of warm mode transfer formula.But, also can judge to carry out fixing process with which pattern in normal mode and low temperature mode based on other information.In this judgement, except the image that will be formed is any in coloured image and black white image, the information such as the text width of the image that will be formed, word size, image color can also be used.Which in addition, also can judge to carry out fixing process with the pattern in normal mode and low temperature mode based on the relevant informix of the toner adhesion amount of the toner image that will be formed.In addition, such as formed glossy image time etc., even if the adhesion amount of toner is few, sometimes also set fixing temperature higher.Therefore, also consider information outside the information that toner adhesion amount is relevant and determine to carry out fixing process with which pattern in normal mode and low temperature mode.

Utilize Fig. 4 that the example of intelligent fixing control is described.Fig. 4 is for forming multiple image A successively, the figure that the temperature variation of the fixing handling part 70 when B, C is described.In the diagram, the process of time is represented from left to right.Image A, C are black white image, and image B is coloured image.Therefore, with low temperature mode, fixing process is carried out to image A, C, and with normal mode, fixing process is carried out to image B.

First, as shown in Figure 4, CPU4 sends image A, the print command of B, C successively when performing image and forming task.It should be noted that, the matched data (マ ッ プ デ ー タ) etc. of the next image of the image that the print command of each image relates to based on print command and this image forms relevant information with image and generates.That is, the print command of image A is based on the Infomiation Production of image A and image B, and the print command of image B generates based on the information of image B and image C, and the print command of image C only generates based on the information of image C.It should be noted that, when carrying out next image formation after image C, consider the print command of the information synthetic image C of this image.

Then, based on the print command of each image, the exposure device 13 of image forming part 10 is utilized to start to expose on photoreceptor 11.Afterwards, each image of development is transferred on paper P at secondary transfer printing clamp-press part N1 respectively, and by fixing clamp-press part N2.In the diagram, represent the time arriving fixing clamp-press part N2 from the exposure to image A to the front end of image A with t1, represent from the front end of image A arrives the time that a certain position to the front end of image B arrives identical a certain position by conveying with t2.Time t1, t2 are the values known when sending the print command of image A, because the print command of image A generates based on the information of image A and image B.

At this, with normal mode, fixing process is carried out to image B with low temperature mode to image A.Wherein, the black white image few to toner adhesion amount and image A, even if carry out fixing process with the temperature of the fixing temperature T2 higher than low temperature mode, the quality of image also can not decline.On the other hand, to image B, image quality may be made to decline when carrying out fixing process with the temperature of the fixing temperature T1 lower than normal mode.Reason is: in order to make toner image fixing well on paper P, needs to heat aptly according to the toner adhesion amount of toner image.

Therefore, as shown in Figure 4, in image processing system 1, when the front end of image B arrives fixing clamp-press part N2, heating arrangement 74 is controlled with the fixing temperature T1 making the heating-up temperature of fixing clamp-press part N2 reach normal mode.At this, as shown in Figure 4, in order to make the heating-up temperature of fixing clamp-press part N2 rise to fixing temperature T1 before the front end of image B arrives, time t3 is needed.Time t3 is to make the heating-up temperature of fixing clamp-press part N2 rise to the shortest time needed for fixing temperature T1 from fixing temperature T2.Therefore, below using t3 as the shortest heating-up time.Therefore, shift to an earlier date the shortest heating-up time t3 when arriving fixing clamp-press part N2 in the front end than image B, warm mode transfer formula is switched to normal mode from low temperature mode.

In addition, the shortest heating-up time t3 is also the value known when sending the print command of image A.Due to time t1, t2, t3 are known, so the time of exposure when warm mode transfer formula is switched to normal mode from low temperature mode from image A represented with Δ t in the diagram is also the value known when sending the print command of image A.In addition, the time t1 in Fig. 4, t2, t3 and time Δ t are the time of the image quality that will be formed when being set to usual degree and enhancing productivity as much as possible.

As shown in Figure 4, by fixing clamp-press part N2 during rising to fixing temperature T1 transferred with the heating-up temperature of paper P fixing clamp-press part N2 after being switched to normal mode of image A from fixing temperature T2.

The heating-up temperature of the fixing clamp-press part N2 in intensification is at more than the fixing temperature T2 of low temperature mode.Therefore, not because causing the image quality of image A to decline by the fixing clamp-press part N2 in intensification.But the paper P that have passed the image A of the fixing clamp-press part N2 in intensification causes the curling of the degree of paperboard in conveying afterwards.

Then, illustrate that curling situation occurs the paper P of the fixing clamp-press part N2 that have passed in intensification.Fig. 5 is the curve map of fixing handling part 70 temperature when representing the fixing clamp-press part N2 making paper P by low temperature mode.Horizontal axis representing time, the longitudinal axis of Fig. 5 represent temperature.And, in Figure 5, about the temperature of fixing handling part 70, the detected temperatures of temperature sensor 76 is represented with double dot dash line, represent the temperature of fixing band 75 near fixing clamp-press part N2 with solid line, be represented by dotted lines the temperature of backer roll 71 near fixing clamp-press part N2.

The temperature near fixing clamp-press part N2 to fixing band 75 and backer roll 71, is detected by the sensor be arranged on for detected temperatures on each position.And Fig. 5 represents makes paper P by the temperature detected by each sensor during the fixing clamp-press part N2 that is in the fixing temperature T2 state of low temperature mode.

As shown in Figure 5, the temperature of fixing band 75 near fixing clamp-press part N2 maintains fixing temperature T2.As previously mentioned, fixing band 75 is structure members of the side, face of the carrying toner image of paper P.By making the temperature of fixing band 75 near fixing clamp-press part N2 be fixing temperature T2, fixing process can be carried out with low temperature mode to the toner image being carried on paper P.

It should be noted that, the temperature of fixing band 75 reduces because its heat is captured by the paper P that have passed through fixing clamp-press part N2.But the amount of the temperature of this reduction is subject to the heating of heating arrangement 74 and supplements, so the temperature of fixing band 75 near fixing clamp-press part N2 also roughly maintains fixing temperature T2 during paper P is by fixing clamp-press part N2.Further, the detected temperatures of temperature sensor 76 maintains the temperature slightly higher than fixing temperature T2.This is because the detection position of temperature sensor 76 is than the position of fixing clamp-press part N2 closer to heating arrangement 74.

The temperature of backer roll 71 near fixing clamp-press part N2 maintained the temperature slightly lower than fixing temperature T2 before paper P arrives fixing clamp-press part N2.This utilizes the heat conduction from fixing band 75 because backer roll 71 does not have thermal source and is heated.In Figure 5, represent that paper P arrives the temperature of fixing band 75 near fixing clamp-press part N2 before fixing clamp-press part N2 and the difference of the temperature of backer roll 71 near fixing clamp-press part N2 with temperature difference TD1.

As shown in Figure 5, the temperature of backer roll 71 near fixing clamp-press part N2 is reduced by fixing clamp-press part N2 due to paper P.This is because the heat of backer roll 71 is captured by the paper P by fixing clamp-press part N2, and at paper P by during fixing clamp-press part N2, the heat conduction from fixing band 75 is blocked by this paper P.

The temperature of backer roll 71 by continuing during fixing clamp-press part N2 to reduce, reaches minimum when the rear end of paper P arrives fixing clamp-press part N2 at paper P.The temperature of fixing band 75 near fixing clamp-press part N2 when representing that the rear end of this paper P arrives fixing clamp-press part N2 with temperature difference TD2 and the difference of the temperature of backer roll 71.

Temperature difference TD2 when the rear end of paper P arrives fixing clamp-press part N2 be greater than paper P arrive fixing clamp-press part N2 before temperature difference TD1.Further, the fixing band 75 near fixing clamp-press part N2 increases to rear end from the front end of the paper P by fixing clamp-press part N2 gradually with the temperature difference of backer roll 71.For paper P, the fixing band 75 of fixing clamp-press part N2 is larger with the temperature difference of backer roll 71, curling more serious by what occur after this fixing clamp-press part N2.That is, the rear end side that have passed the paper P of fixing clamp-press part N2 in Figure 5 occurs more serious than front curling.But, the temperature difference TD2 shown in Fig. 5 is so not large, and what cause the degree of paperboard serious in the conveying after the paper P that have passed fixing clamp-press part N2 can not occur in is curling.

Then, represent in figure 6 and make paper P by the temperature of fixing handling part 70 during fixing clamp-press part N2 in heating up.In other words, Fig. 6 be after switching to normal mode from low temperature mode, the heating-up temperature of fixing clamp-press part N2 rise to fixing temperature T1 by fixing temperature T2 during, paper P is by the curve map of the temperature of the fixing handling part 70 during fixing clamp-press part N2.The situation of this Fig. 6 is different from the situation of Fig. 5, and as in the diagram, paper P causes the curling of the degree of paperboard sometimes in conveying afterwards.

As shown in Figure 6, the temperature of fixing band 75 near fixing clamp-press part N2 rose before paper P arrives fixing clamp-press part N2 from fixing temperature T2.By fixing clamp-press part N2 during the temperature of paper P near the fixing clamp-press part N2 of fixing band 75 rises to fixing temperature T1 from fixing temperature T2.

On the other hand, the temperature of backer roll 71 near fixing clamp-press part N2 is reduced by fixing clamp-press part N2 because of paper P, reaches minimum when the rear end of paper P arrives fixing clamp-press part N2.In figure 6, the temperature of fixing band 75 near fixing clamp-press part N2 when representing that the rear end of paper P arrives fixing clamp-press part N2 with TD3 and the temperature difference of backer roll 71.

As shown in Figure 6, the temperature difference TD3 when rear end of paper P arrives fixing clamp-press part N2 is greater than paper P and arrives temperature difference TD1 before fixing clamp-press part N2.Further, the fixing band 75 near fixing clamp-press part N2 increases to rear end from the front end of the paper P by fixing clamp-press part N2 gradually with the temperature difference of backer roll 71.Therefore, in figure 6, occur more serious than front curling in the rear end side of the paper P that have passed fixing clamp-press part N2.

In Figure 5, as previously mentioned, the temperature of fixing band 75 near fixing clamp-press part N2 is maintained certain with fixing temperature T2, and the temperature of backer roll 71 near fixing clamp-press part N2 reduces.On the other hand, in figure 6, fixing band 75 rises from fixing temperature T2 in the temperature of fixing clamp-press part N2, and on the other hand, the temperature of backer roll 71 near fixing clamp-press part N2 reduces.Therefore, in figure 6, the temperature difference TD3 when rear end of paper P arrives fixing clamp-press part N2 is greater than the temperature difference TD2 of Fig. 5.That is, in the case shown in fig. 6, more serious curling of generation compared with the situation shown in Fig. 5.In the case of fig. 6, the paper P that have passed fixing clamp-press part N2 causes the serious curling of paperboard degree sometimes in conveying afterwards.

So the image processing system 1 of the manner is serious curling in order to suppress paper P to occur, and carries out the fixing process that fixing band 75 does not increase with the temperature difference of backer roll 71.In other words, at paper P by during fixing clamp-press part N2, the temperature difference restriction carrying out controlling each several part controls, and makes the fixing band 75 of fixing clamp-press part N2 position and the temperature difference of backer roll 71 be no more than the poor TDlim of the ceiling temperature be stored in nonvolatile memory 5.As previously mentioned, ceiling temperature difference TDlim is the fixing band 75 of fixing clamp-press part N2 and the maximum temperature difference of allowing of backer roll 71, is can be the temperature that the degree of paperboard can not occur in conveying after it have passed through fixing clamp-press part N2 by the curling suppression of paper P.Ceiling temperature difference TDlim can carry out experiment etc. in advance and obtain.

In the manner, first, before carrying out temperature difference restriction control, emulate in CPU4, to infer the fixing band 75 of paper P by the fixing clamp-press part N2 during fixing clamp-press part N2 and the temperature difference of backer roll 71.Same with Fig. 4, this emulation can form information known in relevant task with image and obtain time t1 according to the thickness of paper P and size, the transporting velocity of paper P, the degree of heat etc. of heating arrangement 74, and t2, t3 and time Δ t are while carry out.Specifically, before the exposure formed at image starts, obtain paper P by the fixing band 75 during fixing clamp-press part N2 and the backer roll 71 respective temperature at fixing clamp-press part N2, and according to calculated temperature, can temperature difference be inferred.

Then, when inferred temperature difference exceedes ceiling temperature difference TDlim, the fixing process that temperature difference restriction controls to carry out paper P is carried out.In the temperature difference restriction of the manner controls, before fixing band 75 and the temperature difference of backer roll 71 of fixing clamp-press part N2 exceed ceiling temperature difference TDlim, the heating of heating arrangement 74 is stopped.About the opportunity of the heating of this heating arrangement 74 of stopping, CPU4 can be utilized in above-mentioned emulation to obtain.Such as, consider the time preset in advance than the opportunity that fixing band 75 and the temperature difference of backer roll 71 exceed ceiling temperature difference TDlim in simulations, the heating of heating arrangement 74 is stopped.Or, the temperature of the backer roll 71 when the rear end of paper P arrives fixing clamp-press part N2 in simulations adds ceiling temperature difference TDlim.In addition, consider before the temperature of fixing band 75 is reached through the opportunity of the temperature that addition is obtained, the heating of heating arrangement 74 is stopped.

In the figure 7, represent that the temperature difference of carrying out the manner limits the temperature of fixing band 75 near fixing clamp-press part N2 when controlling with heavy line.As shown in Figure 7, after paper P enters fixing clamp-press part N2, the rear end of this paper P, by before fixing clamp-press part N2, is controlled by temperature difference restriction, the heating of heating arrangement 74 is stopped, the rising of the temperature of the fixing band 75 made between heating withholding period can be suppressed thus.Further, the temperature difference TD4 when rear end of the paper P when the heating of heating-stopping apparatus 74 arrives fixing clamp-press part N2 represents in the figure 7.

As shown in Figure 7, temperature difference TD4 be suppressed to lower than do not carry out temperature difference restriction control and the heating of not heating-stopping apparatus 74 time temperature difference TD3.Further, as shown in Figure 7, temperature difference TD4 is suppressed to lower than ceiling temperature difference TD1lim.Therefore, in the manner, the rear end side of paper P can be made not occur serious to carry out fixing process curlingly.Thereby, it is possible to suppress paper P by there is paperboard in the conveying after fixing clamp-press part N2.

Further, in the example of fig. 7, make the heating of the heating arrangement 74 of stopping restart when the rear end of paper P have passed fixing clamp-press part N2.Then, reach the fixing temperature T1 of normal mode in the heating-up temperature of fixing clamp-press part N2 after, lower a paper P can be made by fixing clamp-press part N2.That is, in the example in fig. 4, after the heating-up temperature of fixing clamp-press part N2 reaches the fixing temperature T1 of normal mode, the paper P of image B can be made by fixing clamp-press part N2 by fixing clamp-press part N2 at the paper P of image A.

In addition, above-mentioned emulation and temperature difference restriction control when the generation of print command, can only carry out when being judged as the fixing temperature of the fixing temperature of image of this print command lower than the next image of this image.That is, the situation that the fixing temperature of intelligent fixing control is identical with the next image of this image at the image that print command is correlated with and the fixing temperature of next image low can not carry out emulating and temperature difference limits and controls.

In the manner, as mentioned above, infer the fixing band 75 of paper P by the fixing clamp-press part N2 during fixing clamp-press part N2 and the temperature difference of backer roll 71, and based on inferring that the temperature difference is carried out temperature difference restriction and controlled.But, such as be respectively equipped with in the structure of the temperature sensor detecting their temperature near fixing clamp-press part N2 on fixing band 75 and backer roll 71, the actual temperature of fixing band 75 and backer roll 71 can be detected in the process of paper P by fixing clamp-press part N2.Further, the fixing band 75 near the fixing clamp-press part N2 that can detect according to this obtains actual temperature difference with the actual temperature of backer roll 71.

In order to detect the temperature of fixing band 75 near fixing clamp-press part N2, such as shown in Figure 2, the parts of hollow can be used as fixing roller 72, and the position of close fixing clamp-press part N2 inside this fixing roller 72 arrange the temperature sensor 77 represented with double dot dash line.Further, also the temperature sensor 78 represented with double dot dash line can be set for the position of close fixing clamp-press part N2 similarly inside the backer roll 71 of hollow to backer roll 71.

Then, utilize temperature sensor 77, the difference of the detected temperatures of 78 obtains temperature difference, and the temperature difference restriction can carrying out the heating controlling heating arrangement 74 controls, and the temperature difference obtained to make this is suppressed to lower than ceiling temperature difference TDlim.Specifically, paper P by temperature difference during fixing clamp-press part N2 rise to be arranged on ceiling temperature difference below TDlim threshold value heat stop temperature difference time, the heating of heating arrangement 74 is stopped.In this case, the emulation carrying out inferring temperature difference is not needed.It should be noted that, say scrupulously, temperature sensor 77, the detected temperatures of 78 is all slightly different with the actual temperature of backer roll 71 from the actual temperature of the fixing band 75 of fixing clamp-press part N2.Therefore, can by temperature sensor 77, the detected temperatures of 78 carries out the temperature of revised temperature as the fixing band 75 of fixing clamp-press part N2 and the temperature of backer roll 71.

In addition, due to the paper P at image A by fixing clamp-press part N2 during the heating of heating arrangement 74 is temporarily stopped, so how much need some times at the fixing temperature T1 reaching normal mode.But, because the heating stand-by time of heating arrangement 74 is so not long, so the production efficiency that image can not be made to be formed significantly reduces.In other words, the production efficiency that high image is formed can either be maintained, can suppress again that paper P's is curling.

In addition, carry out when temperature difference restriction controls the image formation of the first surface preferably in duplex printing.As previously mentioned, in duplex printing, carry out pros and cons upset after have passed the paper P after fixing clamp-press part N2 and carry to two-sided carrying path 60.When carrying out the image formation of second of paper P by overturning its pros and cons, contrary when its front-end and back-end are formed with the image of first surface.That is, the image that one end that the image carrying out the first surface of paper P becomes rear end when being formed carries out second after overturning pros and cons becomes front end when being formed.

The front of paper P occur serious curling time, the clamp-press part of conveying roller of its front end not by such as configuring along two-sided carrying path 60 may be made.Therefore, carry out the first surface of paper P image formed time rear end side seriously curling, this likely cause pros and cons upset after carry out second image formed time occur paperboard.But, in duplex printing, utilize temperature difference to limit and control, rear end side curling when suppressing the image carrying out first surface to be formed, thus the image that paperboard can not occur and carry out second of the paper P having overturn pros and cons is well formed.

On the other hand, only carry out first surface image formed time and carry out after the image of first surface is formed second image formed time, even if at fixing clamp-press part N2, the rear end side of the throughput direction of paper P occurs curling, and the frequency that paperboard occurs in conveying afterwards also can not be so high.It should be noted that, only carry out first surface image formed time and carry out after the image of first surface is formed second image formed time, also can carry out temperature difference restriction control.This is because the curling this point of paper P can be suppressed not change.In other words, this is owing to can carry out completing stacking in paper delivery portion 55 of paper P that image formed well, and is because be used to complete the multipage paper P that image formed can carry out high-quality bookbinding.

In addition, the ceiling temperature difference TDlim preferably such as different value along with the difference of paper P kind used in image formation.Such as, its rigidity of paper P that thickness is thicker is stronger, more easily paperboard occurs when occurring curling.Therefore, the paper P thicker to thickness, more wishes that minimizing is curling.It can be the ceiling temperature difference TDlim that paperboard degree does not occur in conveying by the curling suppression of paper P that table 1 is shown in image processing system 1 according to the type table of paper P.

As shown in table 1, the paper P that thickness is thick, preferably uses low value to suppress curling as ceiling temperature difference TDlim.It should be noted that, following table 1 is an example of the image processing system 1 of the manner, such as, according to different image processing systems, the value of different temperature differences can be used as ceiling temperature difference TDlim.

[table 1]

The kind of paper	Ceiling temperature difference TDlim [DEG C]
		Thin paper	60
Common paper	50
		Ground paper 1	40
Ground paper 2	38
		Ground paper 3	36
Ground paper 4	34
		Envelope	45

In addition, the ceiling temperature difference TDlim shown in above-mentioned table 1 can utilize paper P to be revised by condition during fixing clamp-press part N2.This is because the temperature difference of fixing band 75 when the rear end of paper P arrives fixing clamp-press part N2 and backer roll 71 is different and become different values by condition during fixing clamp-press part N2 according to this paper P.Such as, the fixing band 75 when the rear end of paper P arrives fixing clamp-press part N2 more becomes little value with the length of temperature difference on the throughput direction of this paper P of backer roll 71 is more short.This is because the length on the throughput direction of paper P is shorter, the heat that backer roll 71 is captured by whole paper P is fewer.Therefore, as paper P, use the paper that the length on its throughput direction is short, ceiling temperature difference TDlim can be made to be modified to lower.Table 2 represents according to the example of the length on the throughput direction of paper P to the modified value that ceiling temperature difference TDlim revises.

[table 2]

Paper is in the length [mm] of throughput direction	The modified value [DEG C] of ceiling temperature difference Tdlim
		＞420	+4
＞364	+2
		＞297	0
210≥	－2

And, fixing band 75 when the rear end of paper P arrives fixing clamp-press part N2 is more little value when this paper P is faster by speed during fixing clamp-press part N2 with the temperature difference of backer roll 71, this be due to paper P faster by transporting velocity during fixing clamp-press part N2 time, backer roll 71 is fewer by the heat taken away of paper P entirety.Therefore, when the transporting velocity of paper P is faster, ceiling temperature difference TDlim can be made to revise lowlyer.Table 3 represents the transporting velocity according to paper P, the example to the modified value that ceiling temperature difference TDlim revises.

[table 3]

Paper sheet delivery speed [mm/s]	The modified value [DEG C] of ceiling temperature difference TDlim
		＞310	－4
＞250	－2
		＞168	0
136≥	+2

In addition, the fixing band 75 when the rear end of paper P arrives fixing clamp-press part N2 is less when making paper P slower by the ascending velocity of the heating-up temperature in fixing clamp-press part N2 process with the temperature difference of backer roll 71.This is because the difference of the temperature of fixing band 75 when the temperature of fixing band 75 when the front end of paper P arrives fixing clamp-press part N2 and the rear end of this paper P arrive fixing clamp-press part N2 diminishes.In addition, the tendency that the fixing band 75 when the difference rear end that is less, paper P with the fixing temperature T2 of low temperature mode and the fixing temperature T1 of normal mode arrives fixing clamp-press part N2 is less with the temperature difference of backer roll 71.Therefore, to ceiling temperature difference TDlim, also can revise based on the difference of the heating-up temperature of the ascending velocity of the heating-up temperature of the paper P of these fixing clamp-press part N2, low temperature mode and normal mode.

The degree that paper P is curling is subject to the impact of the temperature and humidity of environment certainly.Therefore, the sensor of testing environment temperature and humidity can be set in image processing system 1, and utilize the detected value of this sensor to carry out the correction of ceiling temperature difference TDlim.Therefore, wait the length obtained on above-mentioned paper P kind and throughput direction, paper P by the relation of the conditions such as transporting velocity during fixing clamp-press part N2 with ceiling temperature difference TDlim in advance by experiment, this relation is stored in nonvolatile memory 5 as poor the showing of ceiling temperature.Then, when image is formed, as ceiling temperature difference TDlim, use the value showing to determine according to the ceiling temperature difference meeting the condition reference nonvolatile memory 5 that this image is formed to perform temperature difference restriction and control.

[second method]

Second method is described.In the manner, the structure of image processing system 1 etc. are identical with above-mentioned first method.In second method, in the fixing process of fixing handling part 70, also carry out intelligent fixing control.Thus, when paper P is by fixing clamp-press part N2, the fixing band 75 of fixing clamp-press part N2 position increases sometimes with the temperature difference of backer roll 71.Therefore, it is curling that the rear end side that have passed the paper P of fixing clamp-press part N2 may cause paperboard degree serious in conveying afterwards.

Therefore, in second method, also carry out for the fixing band 75 of fixing clamp-press part N2 and the temperature difference of backer roll 71 being suppressed be that lower temperature difference limits and controls, serious curling to make the paper P that have passed fixing clamp-press part N2 not occur.In second method, carry out the temperature difference restriction different from first method and control.In detail, the temperature difference restriction control of the manner is undertaken by the ascending velocity of the heating-up temperature adjusting the paper P of fixing clamp-press part N2.

In the manner, first, in CPU4, based on the information of this task before performing image formation task, the fixing band 75 of paper P by the fixing clamp-press part N2 during fixing clamp-press part N2 and the temperature difference of backer roll 71 is inferred by emulation.Then, when inferred temperature difference exceedes ceiling temperature difference TDlim, carry out temperature difference restriction and control, while carry out the fixing process of paper P.In the temperature difference restriction of the manner controls, the heating of restriction heating arrangement 74, while make the heating-up temperature of the paper P of fixing clamp-press part N2 rise.

The temperature difference restriction utilizing Fig. 8 to describe the manner in detail controls.In fig. 8, also represent that black white image and the paper P of image A and the paper P of coloured image and image B are successively by the temperature of the fixing handling part 70 during fixing clamp-press part N2.In fig. 8, for the situation that the temperature difference restriction carrying out second method controls, represent the temperature of fixing band 75 near fixing clamp-press part N2 with solid line, be represented by dotted lines the temperature of backer roll 71 near fixing clamp-press part N2.

Further, the temperature of fixing band 75 near fixing clamp-press part N2 of not carrying out when temperature difference restriction controls is represented with double dot dash line.The temperature of the fixing band 75 represented with double dot dash line near fixing clamp-press part N2 be do not limit heating arrangement 74 heating and make the heating-up temperature of the paper P of fixing clamp-press part N2 rise to fixing temperature T1 with the shortest heating-up time t3 (Fig. 4) from fixing temperature T2 time temperature, that is, the temperature of fixing band 75 near fixing clamp-press part 75 represented with double dot dash line is the temperature based on emulation.

In the manner, from the exposure of image A during elapsed time Δ t, warm mode transfer formula is also switched to normal mode from low temperature mode.This is because the next image B of black white image and image A is coloured image.Further, by warm mode transfer formula is switched to normal mode from low temperature mode, in process by fixing clamp-press part N2 of the paper P of image A, the temperature of fixing band 75 near fixing clamp-press part N2 rises.

And, in the manner, as shown in Figure 8, carry out the temperature of fixing band 75 near fixing clamp-press part N2 when temperature difference restriction controls, risen lentamente compared with not carrying out of representing with the double dot dash line temperature that temperature difference limits when controlling.This is owing to being controlled by temperature difference restriction, compared with during emulation, limits the heating of heating arrangement 74.

Therefore, the fixing band 75 near the fixing clamp-press part N2 carried out when temperature difference restriction controls and the temperature difference TD5 of backer roll 71 being suppressed is limit temperature difference TD3 when controlling lower than not carrying out temperature difference.Further, as shown in Figure 8, temperature difference TD5 is suppressed to lower than ceiling temperature difference TDlim.Therefore, in the manner, the rear end side of paper P also can be made not occur serious to carry out fixing process curlingly.Thereby, it is possible to suppress the paper P after have passed fixing clamp-press part N2, in conveying, paperboard occurs.

[Third Way]

Third Way is described.In the manner, the structure of image processing system 1 etc. are also identical with aforesaid way.In Third Way, in the fixing process of fixing handling part 70, also carry out intelligent fixing control.Thus, when paper P is by fixing clamp-press part N2, the fixing band 75 of fixing clamp-press part N2 position increases sometimes with the temperature difference of backer roll 71.Therefore, it is curling that the rear end side that have passed the paper P of fixing clamp-press part N2 may cause paperboard degree serious in conveying afterwards.

Therefore, in Third Way, carry out for the fixing band 75 of fixing clamp-press part N2 and the temperature difference of backer roll 71 being suppressed be that lower temperature difference limits and controls, serious curling to make the paper P that have passed fixing clamp-press part N2 not occur.In Third Way, carry out the temperature difference restriction different from aforesaid way and control.In detail, in the temperature difference restriction of the manner controls, make the opportunity switched from low temperature mode to normal mode early than aforesaid way.

In the manner, first, in CPU4, before execution image formation task, based on the information of this task, the fixing band 75 of paper P by the fixing clamp-press part N2 during fixing clamp-press part N2 and the temperature difference of backer roll 71 is inferred by emulation.When inferred temperature difference exceedes ceiling temperature difference TDlim, carry out temperature difference restriction and control, while carry out the fixing process of paper P.The temperature difference restriction of the manner controls, while make shift to an earlier date the opportunity switched from low temperature mode to normal mode, to make the heating-up temperature of the paper P of fixing clamp-press part N2 increase.

The temperature difference restriction utilizing Fig. 9 to explain the manner controls.In fig .9, also represent that black white image and the paper P of image A and the paper P of coloured image and image B are successively by the temperature of the fixing handling part 70 during fixing clamp-press part N2.In fig .9, for the situation that the temperature difference restriction carrying out Third Way controls, represent the temperature of fixing band 75 near fixing clamp-press part N2 with solid line, be represented by dotted lines the temperature of backer roll 71 near fixing clamp-press part N2.

Further, as shown in Figure 9, in Third Way, the exposure from image A during elapsed time Δ t1, warm mode transfer formula is switched to normal mode from low temperature mode.In other words, in the manner, warm mode transfer formula is switched to normal mode from low temperature mode by time Δ t α pre-set time illustrated by Billy Fig. 4.Time α can be set as the time of not enough time Δ t.Time Δ t is the switching time of warm mode transfer formula in emulation.

In other words, in the temperature difference restriction of the manner controls, make warm mode transfer formula switch to the opportunity of normal mode early than the opportunity emulation from low temperature mode.Thus, compared with aforesaid way, fixing band 75 can be made to rise to fixing temperature T1 in advance in the temperature of fixing clamp-press part N2.Therefore, it is possible to make the paper P of the next image B of image A with the opportunity early than aforesaid way by fixing clamp-press part N2.

By warm mode transfer formula is switched to normal mode from low temperature mode, in process by fixing clamp-press part N2 of the paper P of image A, the temperature of fixing band 75 near fixing clamp-press part N2 rises.As shown in Figure 9, in the temperature difference restriction of the manner controls, after paper P enters fixing clamp-press part N2, the heating of heating-stopping apparatus 74 before the rear end of this paper P is by fixing clamp-press part N2.About the stopping of the heating of this heating arrangement 74, identical with the explanation utilizing Fig. 7 of above-mentioned first method to carry out, namely by making the heating of heating arrangement 74 temporarily stop, the temperature difference TD6 when rear end of paper P being arrived fixing clamp-press part N2 suppresses to be lower than ceiling temperature difference TDlim.Thereby, it is possible to the rear end side of paper P does not occur serious to carry out fixing process curlingly, thus can suppress the paper P after have passed fixing clamp-press part N2, in conveying, paperboard occurs.

Therefore, limit in control in the temperature difference of the manner, the fixing band 75 near fixing clamp-press part N2 can be suppressed to be lower than ceiling temperature difference TDlim with the temperature difference TD6 of backer roll 71, and improve the production efficiency of image formation.In the above description, make the heating of heating arrangement 74 temporarily stop (Fig. 7) in the same manner as first method, thus temperature difference TD6 is suppressed be lower than ceiling temperature difference TDlim.But, also can, by the heating (Fig. 8) of restriction heating arrangement 74 in the same manner as second method, temperature difference TD6 be suppressed be lower than ceiling temperature difference TDlim.

[fourth way]

Fourth way is described.In the manner, the structure of image processing system 1 etc. are identical with aforesaid way.In fourth way, in the fixing process of fixing handling part 70, also carry out intelligent fixing control.Thus, when paper P is by fixing clamp-press part N2, the fixing band 75 of fixing clamp-press part N2 position increases sometimes with the temperature difference of backer roll 71.Therefore, it is curling that the rear end side that have passed the paper P of fixing clamp-press part N2 may cause paperboard degree serious in conveying afterwards.

Therefore, in fourth way, carry out for the fixing band 75 of fixing clamp-press part N2 and the temperature difference of backer roll 71 being suppressed be that lower temperature difference limits and controls, serious curling to make the paper P that have passed fixing clamp-press part N2 not occur.In fourth way, carry out the temperature difference restriction different from aforesaid way and control.In detail, the temperature difference restriction of the manner controls to be undertaken by the transporting velocity of adjustment paper P.

In the manner, first, in CPU4, before execution image formation task, based on the information of this task, the fixing band 75 of paper P by the fixing clamp-press part N2 during fixing clamp-press part N2 and the temperature difference of backer roll 71 is inferred by emulation.When inferred temperature difference exceedes ceiling temperature difference TDlim, carry out temperature difference restriction and control, while carry out the fixing process of paper P.In the temperature difference restriction of the manner controls, the transporting velocity before making paper P arrive fixing clamp-press part N2 is slower than common transporting velocity.

The temperature difference restriction utilizing Figure 10 to explain the manner controls.In Fig. 10, also represent that black white image and the paper P of image A and the paper P of coloured image and image B are successively by the temperature of the fixing handling part 70 during fixing clamp-press part N2, and represent the temperature of fixing band 75 near fixing clamp-press part N2 with solid line, be represented by dotted lines the temperature of backer roll 71 near fixing clamp-press part N2.

Further, as shown in Figure 10, in fourth way, the time t1 arriving fixing clamp-press part N2 from the exposure of image A to the front end of image A that the front end of image A is later than through utilizing Fig. 4 to illustrate arrives fixing clamp-press part N2.Time t1 is the time arriving fixing clamp-press part N2 in emulation from the exposure of image A to the front end of image A.That is, the paper P of image A is made to be later than opportunity in emulation by the opportunity of fixing clamp-press part N2.

Specifically, in fourth way, in the rear end of the paper P of image A by before fixing clamp-press part N2, the temperature of fixing band 75 near fixing clamp-press part N2 is made to reach fixing temperature T1.During the paper P of image A passes through fixing clamp-press part N2, make the temperature of the fixing band 75 reaching fixing temperature T1 no longer increase, thus make fixing band 75 less with the temperature difference TD7 of backer roll 71.Thus, temperature difference TD7 can be suppressed in the manner is lower than ceiling temperature difference TDlim.

Owing to making the paper of image A by being later than the time t1 in emulation the opportunity of fixing clamp-press part N2, therefore in the manner, the transporting velocity making paper P arrive fixing clamp-press part N2 is slower than speed during emulation.Specifically, before the front end of the paper P of image A arrives secondary transfer printing clamp-press part N1, or before front end arrives fixing clamp-press part N2 after rear end is by secondary transfer printing clamp-press part N1, the transporting velocity of the paper P of image A is switched to the transporting velocity of transporting velocity when being slower than emulation.This is owing to making transporting velocity slack-off in the process of paper P by secondary transfer printing clamp-press part N1, noise may be produced being transferred in the image A on paper P.That is, the transfer printing of image A to the paper P in secondary transfer printing clamp-press part N1 suitably can be carried out, while suppressed by temperature difference TD7 to be lower than ceiling temperature difference TDlim.Therefore, in the manner, the quality of formed image can not only be guaranteed higher, and the curling of paper P can be alleviated and suppress the paper P after have passed fixing clamp-press part N2, in conveying, paperboard occurs.It should be noted that, also can after the transporting velocity when the transporting velocity of the paper P making image A is temporarily slower than emulation, before the front end of this paper P arrives fixing clamp-press part N2, transporting velocity when making transporting velocity return to emulation.Or, also can before the front end of the paper P making image A arrives secondary transfer printing clamp-press part N1, or rear end is before by secondary transfer printing clamp-press part N1, front end arrives fixing clamp-press part N2, temporarily stops the conveying of this paper P.

[the 5th mode]

5th mode is described.In the manner, the structure of image processing system 1 etc. are identical with aforesaid way.In the 5th mode, in the fixing process of fixing handling part 70, also carry out intelligent fixing control.Thus, when paper P is by fixing clamp-press part N2, the fixing band 75 of fixing clamp-press part N2 position increases sometimes with the temperature difference of backer roll 71.Therefore, it is curling that the rear end side that have passed the paper P of fixing clamp-press part N2 may cause paperboard degree serious in conveying afterwards.

Therefore, in the 5th mode, also carry out for the fixing band 75 of fixing clamp-press part N2 and the temperature difference of backer roll 71 being suppressed be that lower temperature difference limits and controls, serious curling to make the paper P that have passed fixing clamp-press part N2 not occur.In the 5th mode, carry out the temperature difference restriction different from aforesaid way and control.In detail, the temperature difference restriction of the manner controls by making low temperature mode be later than aforesaid way to carry out to the opportunity that normal mode switches.

In the manner, first, in CPU4, before execution image formation task, based on the information of this task, the fixing band 75 of paper P by the fixing clamp-press part N2 during fixing clamp-press part N2 and the temperature difference of backer roll 71 is inferred by emulation.When inferred temperature difference exceedes ceiling temperature difference TDlim, carry out temperature difference restriction and control, while carry out the fixing process of paper P.The temperature difference restriction of the manner controls by making postpone to carry out the opportunity switched from low temperature mode to normal mode.

The temperature difference restriction utilizing Figure 11 to explain the manner controls.In fig. 11, also represent that black white image and the paper P of image A and the paper P of coloured image and image B are successively by the temperature of the fixing handling part 70 during fixing clamp-press part N2, and represent the temperature of fixing band 75 near fixing clamp-press part N2 with solid line, be represented by dotted lines the temperature of backer roll 71 near fixing clamp-press part N2.

Further, as shown in figure 11, in the 5th mode, the exposure from image A during elapsed time Δ t2, warm mode transfer formula is switched to normal mode from low temperature mode.That is, in the manner, warm mode transfer formula is switched to normal mode from low temperature mode with time Δ t β time delay that Fig. 4 is described by Billy.Time Δ t is the switching time of the warm mode transfer formula in emulation.That is, in the temperature difference restriction of the manner controls, the opportunity that warm mode transfer formula is switched from low temperature mode to normal mode is later than the opportunity emulation.

Further, as shown in figure 11, in the 5th mode, during the paper P of image A passes through fixing clamp-press part N2, warm mode transfer formula is low temperature mode.Therefore, in process by fixing clamp-press part N2 of the paper P of image A, the temperature of fixing band 75 near fixing clamp-press part N2 is maintained certain with fixing temperature T2.

By making the paper P of image A maintain fixing temperature T2 by the temperature of the fixing band 75 during fixing clamp-press part N2, the fixing band 75 of fixing clamp-press part N2 is less with the temperature difference TD8 of backer roll 71.Therefore, in the manner, temperature difference TD8 is suppressed to lower than ceiling temperature difference TDlim.Further, in the rear end of the paper P of image A by after fixing clamp-press part N2, by switching to normal mode, the temperature of fixing band 75 is made to rise to fixing temperature T1.It should be noted that, the switching of warm mode transfer formula can be carried out before the rear end of the paper P of image A arrives fixing clamp-press part N2.In this case, be no more than ceiling temperature difference TDlim with temperature difference TD8 and obtain time Δ t2 for condition.

[the 6th mode]

6th mode is described.In the manner, the structure of image processing system 1 etc. are also identical with aforesaid way.In the 6th mode, in the fixing process of fixing handling part 70, also carry out intelligent fixing control.Thus, when paper P is by fixing clamp-press part N2, the fixing band 75 of the position of fixing clamp-press part N2 increases sometimes with the temperature difference of backer roll 71.Therefore, it is curling that the rear end side that have passed the paper P of fixing clamp-press part N2 may cause paperboard degree serious in conveying afterwards.

Therefore, in the 6th mode, also carry out for being that lower temperature difference limits and controls by suppressing in the fixing band 75 of fixing clamp-press part N2 and the temperature difference of backer roll 71, serious curling to make the paper P that have passed fixing clamp-press part N2 not occur.In the 6th mode, different from aforesaid way, the formation order of switching image when forming multiple image continuously carries out temperature difference restriction control.

In the manner, the situation of image A as shown in Figure 4, image B, image C tri-images formation is described.In the manner, image A and image C is black white image similarly, image B is coloured image.Therefore, by the fixing control of intelligence, with the fixing temperature T2 of low temperature mode, fixing process is carried out to the paper P of image A and image C, with the fixing temperature T1 of normal mode, fixing process is carried out to the paper P of image B.

In this case, as shown in Figure 4, usually also print command is sent according to the order of image A, image B, image C.That is, under normal conditions, the first surface of paper P1 forms image A, at paper P1 by during two-sided carrying path 60, the first surface of paper P forms image B, after formation image B, second of paper P1 forms image C.

But, in the manner, during the print command of synthetic image, also consider that the image-related temperature before the image of this print command adjusts pattern information.Then, the order of the print command sending the generation image of print command and the next image of this image is judged whether to switch to carry out image formation.

To this, the situation during generation of key diagram as the print command of B.First, when the print command of synthetic image B, judge that whether fixing temperature under the warm mode transfer formula of the image A before image B and the image C after image B is all lower than the fixing temperature under the warm mode transfer formula of image B.When fixing temperature all lower than image B of the fixing temperature of image A and image C, judge whether image B is the image that will be formed on the first surface of paper P.Further, if image B is the image that will be formed on the first surface of paper P, then judge that whether image C is second image that will be formed to the paper P defining image on the first face.Then, if image C is second image that will be formed to paper P, then switch the order of image B and image C, after formation image C, carry out the formation of image B.Then, in the fixing process of image C, because the fixing temperature under the warm mode transfer formula of image B is higher than the fixing temperature under the warm mode transfer formula of image C, therefore carries out temperature difference restriction and control.

Then, utilize Figure 12, specifically describe first surface at same paper P with second on form image A and image C, the situation forming image B on the first surface of the paper P different from image A and image C respectively.At this, to form the paper P of image A and image C for paper P1.That is, the first surface of paper P1 forms image A, second of paper P1 forms image C.The first surface of the paper P2 different from paper P1 forms image B.

First, for image A, owing to being the initial image formed, therefore generate print command according to the information of image A and image B.In the print command of image A, image B is normal mode, and image A is low temperature mode.Therefore, as shown in figure 12, the exposure from image A during elapsed time Δ t, warm mode transfer formula is switched to normal mode from low temperature mode.Then, when the paper P1 carrying image A is on the first face by fixing clamp-press part N2, the temperature difference carrying out the heating of heating arrangement 74 is stopped in the same manner as Fig. 7 of above-mentioned first method limits and controls.Therefore, the rear end carrying the paper P1 of image A on the first face suppresses to be lower than ceiling temperature difference TDlim with the temperature difference TD9 of backer roll 71 at the fixing band 75 of fixing clamp-press part N2.The paper P1 being defined image A by fixing clamp-press part N2 on the first face, after pros and cons upset, is carried to two-sided carrying path 60.Further, the paper P1 defining image A on the first face, by after fixing clamp-press part N2, makes the heating of the heating arrangement 74 stopped restarting.

Then, according to the print command of the information synthetic image B of image A, image B, image C.At this, because the warm mode transfer formula of the image C after the image A before image B and image B is all low temperature mode, therefore the fixing temperature of these images is all the fixing temperature T2 lower than the fixing temperature T1 of normal mode and image B.In addition, image B is the image that will be formed to the first surface of paper P2.In addition, image C is will to second of the paper P1 image formed of formation having carried out image A on the first face.Therefore, be judged as the order of switching image B and image C, before image B, form image C.

Then, in the print command of image C, order is normal mode by the image B after switching, and its fixing temperature T1 is higher than the fixing temperature T2 of the image C of low temperature mode.Therefore, as shown in figure 12, when the paper P1 carrying image C is on the second surface by fixing clamp-press part N2, the temperature difference carrying out the heating of heating arrangement 74 is stopped in the same manner as Fig. 7 of above-mentioned first method limits and controls.Therefore, the rear end carrying the paper P1 of image C is on the second surface suppressed to lower than ceiling temperature difference TDlim with the temperature difference TD10 of backer roll 71 at the fixing band 75 of fixing clamp-press part N2.Further, the paper P1 defining image C in the second face, by after fixing clamp-press part N2, makes the heating of the heating arrangement 74 stopped restarting.Then, reach the fixing temperature T1 of normal mode at the fixing band 75 of fixing clamp-press part N2 after, make the paper P2 carrying image B on the first face by fixing clamp-press part N2.

Therefore, in the manner, can reduce and form the curling of the paper P1 of image A and image C on two-sided and the generation suppressing paperboard, and the fixing process of image B to the first surface of paper P2 can be carried out well.It should be noted that, in the manner, the formation order of switching image is carried out to temperature difference and limited situation about controlling and be illustrated in the same manner as first method (Fig. 7).But, be not limited to first method, also can carry out limiting with the same temperature difference of either type in the second to the 5th mode (Fig. 8 ~ Figure 11) controlling.

As being described in detail above, in the image processing system 1 of aforesaid way, carry out intelligent fixing control.Further, carry out intelligent fixing control, control while perform the temperature difference restriction carrying out image formation, make paper P be no more than ceiling temperature difference TDlim by the fixing band 75 of the fixing clamp-press part N2 during fixing clamp-press part N2 with the temperature difference of backer roll 71.Thus, reduce the power consumption in fixing process, and curling generation can be suppressed.

Need the expression illustrated, present embodiment just illustrates, instead of limitation of the present invention.Therefore, the present invention obviously can carry out various improvement, distortion in the scope not departing from its purport.Such as, the invention is not restricted to color printer, be also applicable to duplicating machine etc.And, such as image processing system 1 also can the different temperature difference illustrated by the above-mentioned first to the 5th mode limit in control, the production efficiency formed from the view point of image and the power consumption of fixing handling part 70, the restriction of preferable temperature difference controls and carries out.Further, such as, in the fixing control of intelligence, warm mode transfer formula is not limited to normal mode and low temperature mode, also can arrange the pattern that fixing temperature is high compared with normal mode and fixing temperature is low compared with low temperature mode pattern.

Claims (11)

1. an image processing system, has:

Image forming part, it forms toner image, by being transferred on sheet material by this toner image, sheet material forms toner image;

Fixing handling part, it has the heating part of the heating accepting thermal source and jointly forms the pressurization part of clamp-press part with described heating part, makes the sheet material transferred with toner image carry out fixing process by described clamp-press part;

Apparatus control portion, each several part of its control device and carry out image formation;

The feature of this image processing system is to have:

Heated side temperature efferent, it exports the heated side temperature value of the temperature of the position at described clamp-press part representing described heating part;

Pressure side temperature efferent, it exports the pressure side temperature value of the temperature of the position at described clamp-press part representing described pressurization part;

When the fixing required heat of the toner image utilizing described image forming part to be transferred on sheet material lacks, with fixing required heat multidate ratio, sheet material is set as lower by the target of described heated side temperature value during described clamp-press part and fixing temperature by described apparatus control portion;

Described apparatus control portion carries out the fixing control of intelligence of the heating controlling described thermal source, makes described heated side temperature value before sheet material arrives described clamp-press part become the temperature of more than the fixing temperature set this sheet material;

And, for the second sheet material continued through after the first sheet material of described clamp-press part and the first sheet material, when fixing temperature higher than the first sheet material of the fixing temperature of the second sheet material, described apparatus control portion performs the temperature difference restriction forming image and controls, and makes the first sheet material be no more than by the difference of described heated side temperature value during described clamp-press part and described pressure side temperature value and temperature difference the ceiling temperature preset poor.

2. image processing system as claimed in claim 1, is characterized in that,

Described heated side temperature efferent is the sensor of the temperature of the position at described clamp-press part detecting described heating part;

Described pressure side temperature efferent is the sensor of the temperature of the position at described clamp-press part detecting described pressurization part;

Described apparatus control portion, in described temperature difference restriction controls, when described temperature difference reaches the heating stopping temperature difference being redefined for the following value of described ceiling temperature difference, stops the heating of described thermal source.

3. image processing system as claimed in claim 1, is characterized in that,

Described heated side temperature efferent and described pressure side temperature efferent are described apparatus control portion;

Described apparatus control portion is before utilizing described image forming part to start to form the toner image of the first sheet material, and described heated side temperature value when making described heated side temperature value rise to the fixing temperature of the second sheet material to making the first sheet material utilize described thermal source to heat by described clamp-press part and described pressure side temperature value emulate;

Based on the described heated side temperature value obtained by described emulation and described pressure side temperature value, the guess value of the described temperature difference when rear end obtaining the first sheet material arrives described clamp-press part infers temperature difference;

When the described supposition temperature difference obtained exceedes described ceiling temperature difference, determine that performing the restriction of described temperature difference controls;

When determining that performing the restriction of described temperature difference controls, performing the restriction of described temperature difference when the image of formation first sheet material and controlling.

4. image processing system as claimed in claim 3, is characterized in that,

Described apparatus control portion based on calculated described heated side temperature value and described pressure side temperature value, is obtained and is namely exceeded opportunity in described emulation the opportunity that the first sheet material exceedes described ceiling temperature difference by the described temperature difference during described clamp-press part;

In described temperature difference restriction controls, before exceeding opportunity described in being obtained by described emulation, stop the heating of described thermal source;

After the rear end of the first sheet material have passed described clamp-press part, the heating of the described thermal source stopped being restarted.

5. image processing system as claimed in claim 3, is characterized in that,

Described apparatus control portion limits the heating of described thermal source in described temperature difference restriction controls, and makes the rising degree of described heated side temperature value in described temperature difference restriction controls slower than the rising degree in described emulation.

6. image processing system as claimed in claim 3, is characterized in that,

Described apparatus control portion is in the restriction of described temperature difference controls, and before the front end of the first sheet material arrives described image forming part and the rear end of the first sheet material is slower than the transporting velocity of the first sheet material in described emulation by the transporting velocity that the front end of the first sheet material after described image forming part arrives first sheet material of at least one party during described clamp-press part.

7. image processing system as claimed in claim 3, is characterized in that,

Described apparatus control portion is in the restriction of described temperature difference controls, and the rising that the rising making to utilize the heating of described thermal source to make described heated side temperature value start to rise is later than in described emulation the opportunity of starting starts opportunity.

8. the image processing system as described in claim 4 or 5, is characterized in that,

Described apparatus control portion is in the restriction of described temperature difference controls, and the rising making to utilize the heating of described thermal source to make described heated side temperature value start to rise starts opportunity early than the rising in described emulation the opportunity that starts.

9. the image processing system according to any one of claim 1 to 7, is characterized in that, has:

Turning part, it makes the pros and cons upset being formed with the sheet material of image by described clamp-press part on the first face;

Two-sided carrying path, the sheet material that have passed turning part is transported to than the position of described image forming part near upstream in order to the back side at this first surface that is second form image by again;

When the first surface of the first sheet material and second carry out implementing fixing process to first surface in the duplex printing of image formation successively, described apparatus control portion is carried out the restriction of described temperature difference and is controlled.

10. the image processing system according to any one of claim 1 to 7, is characterized in that, has:

Turning part, it makes the pros and cons upset being formed with the sheet material of image by described clamp-press part on the first face;

Two-sided carrying path, the sheet material that have passed turning part is transported to than the position of described image forming part near upstream in order to the back side at this first surface that is second form image by again;

Described apparatus control portion at the fixing temperature of the second sheet material lower than the fixing temperature of the first sheet material, and by the fixing temperature of the fixing temperature of the sheet material of described clamp-press part lower than the first sheet material before the first sheet material, and the first sheet material be form the sheet material of image on a first side thereof, the second sheet material is when forming the sheet material of image on a second side by described two-sided carrying path

The image carrying out the second sheet material before the image of the first sheet material is formed is formed, and performs described temperature difference restriction control when the image of the second sheet material is formed.

11. image processing systems according to any one of claim 1 to 7, is characterized in that,

There is storage part, this storage part stores the thickness of the first sheet material, the first sheet material length in the conveying direction, the first sheet material shown by the relation of at least one condition in speed during described clamp-press part and described ceiling temperature difference and ceiling temperature difference;

Described apparatus control portion, in described temperature difference restriction controls, uses the value showing to determine with reference to described ceiling temperature difference poor as described ceiling temperature.