JPH09230738A - Image forming device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily estimate the temperature range of a pressure roller and to obtain a required fixing ratio and a small curling quantity, even if the temp. of the pressure roller is low or high by controlling a heat source in accordance with the count value of a job counter, with a temperature control means. SOLUTION: The temp. of a heating roller 12 is detected by a temperature detecting means 15a, the heat source 13 is controlled by the temperature control means 50a and a recording medium to which a developer is transferred from a latent image carrying member is pressed on the heating roller 12 by the pressure roller 14. At this time, a start-up for starting printing from a printing standby state where the latent image carrying member is stopped is executed by the job counter 70 and an operation from the execution of the printing to the stopping of the latent image carrying member is counted as one job. Then, the temperature control means 50a controls the heat source 13 in accordance with the count value of the job counter 70. Thus, the temperature range of the pressure roller 14 can be easily estimated and the required fixing ratio and the small curling quantity can be obtained even if the temp. of the pressure roller 14 is low or high.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a toner (developer).
To an image forming apparatus including an electrophotographic apparatus such as a copying machine and a laser printer using the same, and a control method thereof, and particularly to an image forming apparatus having a fixing device provided with a heat source for fixing toner onto a recording medium by heat and its control Regarding the method.

[0002]

2. Description of the Related Art In a conventional fixing device provided with a heat source of an image forming apparatus, the temperature of the fixing device is detected by a thermosensitive element (temperature sensor) such as a thermistor, and a halogen lamp or the like is set at a preset temperature level. The heat source was controlled to control the temperature (see, for example, Japanese Patent Application No. 7-271289).

FIG. 25 is an explanatory view of a conventional example. In FIG. 25, the conventional image forming apparatus is provided with a fixing device 11, a temperature measuring device 15, a fixing device temperature control device 16, an initial operation necessity detecting device 17, a print command issue detecting device 18, and a drive control device 20. The fixing device 11 is provided with a heat roller 12, a heat source 13, and a pressure roller 14.

The fixing device 11 is a heat source 1 such as a halogen lamp.
The pressure roller 14 presses the recording medium against the heat roller 12 having the built-in 3 to fix the recording medium. The temperature measuring means 15 comprises a heat sensitive element such as a thermistor that detects the surface temperature of the heat roller 12. The fixing device temperature control means 16 detects the surface temperature of the heat roller 12 from the temperature measuring means 15 and the initial operation necessity detecting means 1.
Initial operation instruction from 7 and print command issuance detection means 1
The temperature control of the heat source 13 and the control of the drive control means 20 are performed by a print command or the like from 8.

The initial operation necessity detecting means 17 is an opening / closing operation of an apparatus cover which can be opened / closed by turning on the apparatus power, removing a jam of a medium with the apparatus turned on, and replacing consumables, or the like. The detection is performed when an initial operation such as reception of a device reset signal from a print data transmission source (host) such as a computer or a word processor is required.

The print command issuance detection means 18 detects the issuance of a print command from a computer, word processor or the like. The drive control means 20 controls the drive of the fixing device 11 and the like.

FIG. 26 is an explanatory diagram of switching of the fixing temperature in the conventional example. In FIG. 26, the print command shows a case where the issuance of the print command (corresponding to four pages) is detected after the completion of the predetermined initial operation. VR is a VR signal (video synchronized request) to which the image forming apparatus responds to the host after a lapse of t ₁ time after detecting the print command. The print data is print data sent from the host after t ₂ time has elapsed since the VR signal was received. During printing / standby, the time from the VR signal transmission until the print data is interrupted until t ₃ is defined as printing.

In the fixing device set temperature of the conventional example (1), when the printing is started from the waiting state (standby: fixing device control temperature 140 ° C.) after performing a predetermined initial operation, the fixing device is set. The temperature setting (control temperature) of the target temperature of 1 is detected 17 times after the issuance of the print command is detected, both when the printing is continued (print command ~) and when it is not continued (print command).
0 ° C is set, and the target temperature after the lapse of t ₄ hours after the completion of sending the print data is the control temperature of 140 ° during standby (standby).
It was C.

As described above, when the print data does not arrive after waiting the predetermined time t ₄ after the completion of the print data transmission, the control of the fixing device is shifted to the standby mode. In order to keep the pressure roller on, the pressure roller was unnecessarily heated.

The fixing temperature of the fixing device of the conventional example (2) is set to a fixing device when printing is started from a waiting state (standby: fixing device control temperature 140 ° C.) after performing a predetermined initial operation. The temperature setting (control temperature) is set to 160 ° C as the control temperature of the fixing device at the time of printing the first page (print command), and 170 ° C if printing is continued (print command). The target temperature after the lapse of t ₃ hours from the completion of sending the print data was set to 140 ° C., which is the control temperature during standby.

As described above, the control mode of the heat source 13 such as the halogen lamp is shifted to the standby mode after the time t ₃ shorter than the time t ₄ of the conventional example (1), so that the light is forcibly turned off. For this reason, the pressure roller of the fixing device was not unnecessarily heated after printing.

FIG. 27 is an explanatory diagram of the pressure roller temperature during intermittent printing. In FIG. 27, after the initial operation is completed,
The temperature of the pressure roller when one print is repeated 80 times at intervals of 30 seconds, and the temperature of the pressure roller when the print operation of start-up-one-page printing-stop after that is repeated at one-second intervals are shown. ing.

FIG. 28 is an explanatory view of the curl of the printing paper.
FIG. 28 (a) is an explanation of the forward curl, and FIG. 28 (b) is an explanation of the reverse curl. In FIG. 28A, the printing on the printing surface is shown in an enlarged manner, and the positive curl is curved so as to have the center on the printing surface side, in other words, it is curved to the heat roller 12 side of the fixing device. In general, the positive curl amount increases as the temperature of the pressure roller increases.

In FIG. 28 (b), the reverse curl refers to curving so as to have its center on the side opposite to the printing surface side, in other words, curling to the pressure roller 14 side of the fixing device. When the temperature of the pressure roller becomes low, and when the medium absorbs moisture, the amount of reverse curl increases.

[0015]

The above-mentioned prior art has the following problems. (A) In the above-mentioned conventional example (2), it may not be possible to cope with changes in device specifications such as printing speed and warm-up time (Warm Up Time) for heating the pressure roller. Causes a stack defect and a large curl, which makes it difficult to handle as an output medium.

For example, when the Warm Up Time is not sufficient and the pressure roller is not warmed to the required temperature at cold start, (1) the fixing device at the time of printing the first first page is Control temperature and (2) Control temperature setting for continuing printing (1) / (2) = 160
The required fixing rate cannot be secured unless the temperature of ° C / 170 ° C is shifted to the high temperature side.

However, if printing is repeated while shifting to the high temperature side, the pressure roller will be heated more than necessary as shown in FIG. In this case, if the pressure roller that is warmed more than necessary and the control temperature that is shifted to the high temperature side are combined, the fixing rate becomes unnecessarily high, and the positive curl amount exceeds the allowable amount. That is, with respect to the temperature change of the pressure roller, the fixed set of control temperatures (1) and (2) could not satisfy the two performances of the fixing rate and the positive curl amount.

(B) In the control in which the control temperature after the printing is finished and the lighting start timing are limited to one, when the next printing is executed before the sufficient time elapses, the heat roller temperature is higher than the standby temperature. Since it is warm, the temperature of the fixing device reaches a peak before or during entry of the medium.
For this reason, the balance between the fixing ratio and the positive curl was lost due to the deviation from the optimum fixing device temperature timing. As a result, the fixing rate may decrease.

Further, if the temperature of the fixing device reaches a peak before or during the entry of such a medium, the timing at which the medium enters and the timing at which the temperature of the heat roller rises are deviated from each other. Since the pressure roller is warmed, the temperature of the pressure roller rises and tends to increase. For this reason, there has been a problem such as an excessive amount of curl.

In the conventional example, since the heat roller temperature varies at the time of receiving the print command, whether or not the halogen lamp (heater) is turned on (the heat roller temperature is C) varies when the medium passes. . Therefore, there was a large variation in the fixing rate.

For example, immediately after the end of printing, the heat roller temperature does not drop much. In such a case, if the halogen lamp lighting command is issued immediately after the next printing command, the energy generated by lighting is mainly used to warm the pressure roller, and the heat roller temperature is the paper (medium). Control temperature is reached before approach. However,
On the other hand, when the most important sheet is passed, it remains off, and fixing is performed with residual heat. In the worst case, the temperature of the trailing edge of the paper becomes low and the light is turned on again. In such a case, it is necessary to add an extra temperature margin to the control temperature.

(C) In a device with a short distance between media,
Since the distance between the media is short, it is difficult to heat the pressure roller, and the temperature of the pressure roller decreases during continuous printing. In particular, when the medium absorbs moisture, this tendency becomes remarkable and reverse curling of the medium occurs.

For this reason, a stack defect occurs, and in the double-sided printing apparatus, the reverse curl is large at the time of printing on the back side, so that it becomes difficult to separate the medium from the photosensitive drum surface.
There was a media jam.

For example, when continuous printing is performed due to a short distance between sheets, the pressure roller temperature decreases as shown by the pressure roller temperature change curve in FIG. 9, and when the medium absorbs moisture, reverse curl occurs. Was.

The present invention solves such a conventional problem, estimates the pressure roller temperature by using the concept of a job counter, and changes the control temperature of the fixing device based on this to estimate the pressure roller temperature. When the print command is received, print the timing of lighting the heat source such as a halogen lamp even if the heat roller temperature varies when the print command is received. Adjust according to the temperature of the heat roller at that time so that fixing is always performed in the optimum temperature range.Furthermore, even if the medium absorbs moisture, the sequence to warm the pressure roller temperature by user settings etc. is continuously printed. It is intended to be inserted inside to suppress reverse curl.

[0026]

FIG. 1 is a diagram for explaining the principle of the present invention. In FIG. 1, 11 is a fixing device, 12 is a heat roller, 13 is a heat source, 14 is a pressure roller, and 15a is a temperature detecting means. , 50a is a temperature control means, and 70 is a job counter.

The present invention has the following structure in order to solve the above conventional problems. (1): A heat roller 12 having a built-in heat source 13, and a temperature detecting means 15a for detecting the temperature of the heat roller 12.
A pressure roller 14 for pressing the recording medium having the developer transferred from the latent image holding member against the heat roller 12, a temperature control means 50a for controlling the heat source 13, and the latent image holding member being stopped. The temperature control means 50 is provided with a job counter 70 that starts the printing from a waiting state for printing and counts the operation until the latent image holding member is stopped after the printing is performed as one job.
The a controls the heat source 13 according to the count value of the job counter 70.

(2): The heat roller 12 having the built-in heat source 13, the temperature detecting means 15a for detecting the temperature of the heat roller 12, and the recording medium on which the developer is transferred from the latent image holding member. The pressure roller 14 to be pressed against and the temperature control means 50a for controlling the heat source 13.
In the method of controlling the image forming apparatus, the latent image holding member is activated to start printing from a waiting state where the latent image holding member is stopped, and the latent image holding member is stopped by executing printing. The operation up to is counted as one job,
According to the counted number of jobs, the temperature control means 5
0a controls the heat source 13.

(3): In the image forming apparatus control method of (2), the counted number of jobs is held in a storage area. (4): In the image forming apparatus control method of (3), the counted number of jobs is stored in a storage area that is retained even after the power is turned off.

(5): In the control method of the image forming apparatus according to (2) to (4), control for setting the heat roller 12 at the time of printing the first first page which starts printing from the print waiting state. The temperature is changed according to the number of jobs.

(6): In the image forming apparatus control method of (5), the control temperature to be changed according to the number of jobs is selected from a control temperature group prepared in advance.

(7): In the control method of the image forming apparatus according to (6), actual control is performed from the control temperature group selected according to the temperature of the heat roller 12 at the time of receiving the print command. The temperature and the drive timing of the heat source 13 are determined.

(8): In the method for controlling the image forming apparatus according to (2) to (4), the heat roller is used when printing is continued from the first page where printing is started from the print waiting state. The control temperature set to 12 is selected according to the number of jobs.

(9): In the control method of the image forming apparatus of (2) to (4), when the power is turned on, the cover is opened / closed, or the initial operation is executed by a reset signal, the temperature of the heat roller 12 is changed. Is higher than the predetermined temperature, the number of jobs held after the power is turned off is counted as an initial value.

(10): In the method of controlling the image forming apparatus of (2) to (4), when the power is turned on, the cover is opened / closed, or the initial operation is executed by a reset signal, the temperature of the heat roller 12 is increased. Is lower than the determined temperature, the initial value of the number of jobs is counted as zero.

(11) The heat roller 12 containing the heat source 13, the temperature detecting means 15a for detecting the temperature of the heat roller 12, and the recording medium having the developer transferred from the latent image holding member on the heat roller 12. The pressure roller 14 to be pressed and the temperature control means 50a for controlling the heat source 13
In a method of controlling an image forming apparatus including the above, when performing continuous printing, a print end operation and a print start operation are inserted during the continuous printing.

(12): The control method of the image forming apparatus described in (2) to (11) above is used as the control method of the printer of the information processing system. (Operation) The operation based on the above configuration will be described.

The temperature detection means 15a detects the temperature of the heat roller 12, the temperature control means 50a controls the heat source 13, and the pressure roller 14 heats the recording medium on which the developer is transferred from the latent image holding member. In the image forming apparatus that is pressed against the roller 12, the job counter 70 is activated to start printing from a waiting state where the latent image holding member is stopped, the printing is executed, and the latent image holding member is stopped. The operation up to is counted as one job, and the temperature control means 50a controls the heat source 13 according to the count value of the job counter 70. For this reason,
It is possible to easily estimate the temperature range of the pressure roller 14, and it is possible to obtain a required fixing ratio and a small positive curl amount when the temperature of the pressure roller 14 is low or high.

Further, the temperature of the heat roller 12 is detected by the temperature detecting means 15a, the heat source 13 is controlled by the temperature controlling means 50a, and the recording medium on which the developer is transferred from the latent image holding member is pressed by the pressure roller 14. In the method of controlling the image forming apparatus that presses against the heat roller 12, the latent image holding member is activated to start printing from a waiting state for printing, and the latent image holding member is The operation up to the stop is counted as one job, and the temperature control means 50a controls the heat source 13 according to the counted number of jobs. Therefore, the pressure roller 14
The temperature range of the pressure roller 1 can be easily estimated.
It is possible to obtain a required fixing ratio and a small amount of positive curl when the temperature of 4 is low or high.

Further, the counted number of jobs is held in the storage area. Therefore, the number of jobs can be easily read from the storage area when necessary. Further, the counted number of jobs is stored in a storage area that is retained even after the power is turned off. For this reason, the temperature range of the pressure roller 14 can be easily estimated even if the apparatus power is turned off and then turned on again.

Further, the control temperature set in the heat roller 12 at the time of printing the first page starting printing from the waiting state for printing is changed according to the number of jobs. Therefore, it is possible to obtain a necessary fixing ratio and a small amount of positive curl at the time of printing the first page.

The control temperature to be changed according to the number of jobs is selected from a control temperature group prepared in advance, and the actual control temperature is the heat roller at the time when the print command is received. According to the temperature of 12, the temperature is determined from the selected control temperature group, and the driving timing of the heat source 13 is determined. Therefore, finer control can be performed, and a required fixing rate and a small positive curl amount can be reliably obtained.

Further, the control temperature to be set in the heat roller 12 when the printing is continued after the first page where printing is started from the print waiting state is selected according to the number of jobs. For this reason, even when the printing is continued after the first page where the printing is started from the waiting state for printing, the required fixing ratio and a small curl amount can be obtained.

Further, when the power is turned on, the cover is opened / closed, or the initial operation is executed by a reset signal, if the temperature of the heat roller 12 is higher than a predetermined temperature, the heat roller 12 is held even after the power is turned off. The number of jobs that have been created is counted as the initial value. Therefore, even if the temperature of the fixing device is not lowered so much after the power source of the device is turned off, the temperature range of the pressure roller 14 can be easily estimated from the temperature of the heat roller 12 at that time even if the fixing device is turned on again. ,
A required fixing rate and a small amount of positive curl can be obtained.

When the power is turned on, the cover is opened or closed, or the initial operation is performed by a reset signal, if the temperature of the heat roller 12 is lower than a predetermined temperature, the initial value of the number of jobs is set to the initial value. Count as zero. Therefore, even if the temperature of the fixing device is sufficiently lowered after the power of the device is turned off, the temperature range of the pressure roller 14 can be easily estimated from the temperature of the heat roller 12 at that time. It is possible to obtain the required fixing rate and a small amount of positive curl.

Further, the temperature detecting means 15a detects the temperature of the heat roller 12, and the temperature controlling means 50a detects the heat source 13.
In the control method of the image forming apparatus in which the pressure roller 14 presses the recording medium on which the developer is transferred from the latent image holding member to the heat roller 12, when continuous printing is performed, printing is performed during the continuous printing. Include the end operation and print start operation. Therefore, the temperature of the pressure roller 14 can be raised for each predetermined number of sheets during continuous printing, and the reverse curl can be suppressed even for a medium that has absorbed moisture.

Further, the control method of the image forming apparatus is used as the control method of the printer of the information processing system. Therefore, it is possible to obtain a printer of an information processing system having a required fixing rate and a small curl amount, and a required fixing rate and a small curl amount during continuous printing.

[0048]

2 to 24 are diagrams showing an embodiment of the present invention, and an embodiment of the present invention will be described below with reference to the drawings. 1): Description of Printer Device FIG. 2 is an explanatory diagram of an overview of a printer device and a paper path route according to the embodiment. In FIG. 2, a printer apparatus which is an image forming apparatus includes a paper path route 33, a paper cassette 39 for storing paper, a pick roller 36 for supplying the paper to the printer, and a registration roller 35 for aligning the printing front end. A transfer roller 32 that transfers a toner image onto a sheet, a photoconductor drum 31 that is a latent image holding member on which a toner image is formed and is carried, and a toner image is fixed on the sheet onto which the toner image is transferred. A fixing device 11 for performing
A discharge roller 34 for discharging the recorded sheet, a process cartridge 30 for performing a recording process, an optical system 37 for exposing the photosensitive drum 31 to form a latent image, and a power source 38. Have.

In response to the print command, the printer device starts to start up the optical system 37, the process cartridge 30 and the fixing device 11, and when a predetermined print preparation is completed, the paper (medium) accommodated in the paper cassette 39 is picked up by the pick roller 36. To pick.

The picked paper is temporarily stopped by the registration roller 35 for aligning the leading edge of the print, and is conveyed to the transfer portion between the photosensitive drum 31 and the transfer roller 32 while keeping timing with the optical system 37. The toner image formed on the photoconductor drum 31 is transferred to a sheet at the transfer unit and heads for the fixing device 11. In the fixing device 11, the heat roller 12 and the pressure roller 14 fix the toner to the sheet by heat and pressure. After that, the paper is discharged by the paper discharge roller 34.

2): Description of Printer Engine FIG. 3 is a block diagram showing an outline of the printer engine. In FIG. 3, the printer engine 4 of the printer device
3, a mechanism unit 44 and a mechanism control unit 45 are provided.

The mechanism section 44 includes, for example, the fixing device 11 and
A transfer system 52 that transfers the toner image formed on the photoconductor drum 31 to a sheet, an optical system 51 that exposes the photoconductor drum 31 on the sheet, and a conveyance system 53 that conveys the sheet.

Further, the mechanism control section 45 includes various sensors 4
7, and an optical system controller 48 for controlling the optical system 51.
And a motor controller 49 for rotating the photosensitive drum 31 and the fixing device 11, and a fixing device temperature controller 50.

Further, the mechanical section 44 receives a print control signal such as a print command and a video signal of the print data itself from the host 46 side such as a personal computer or a word processor. In this way, the mechanism control unit 45 communicates with the host 46,
Printing preparation and printing are repeatedly performed for the printer mechanism of No. 4.

3): Description of the function of the control system FIG. 4 is a functional block diagram of the control system. In FIG.
The printer device includes a heat roller 12 having a halogen lamp 13 as a heat source, a pressure roller 14 for pressing a sheet against the heat roller 12, and the halogen lamp 13.
11 having AC driver 62 for driving
A temperature sensor 71 such as a thermistor for measuring the temperature of the surface of the heat roller 12, a CPU (central processing unit) and a program 60 provided in the mechanism control unit 45.
And an A / D converter 61 for converting analog data of the temperature sensor 71 into digital data, an operation / display unit 63 for user operation and display to the user, and control of connection with the host 46. And an interface 64 for performing.

Here, the heat roller 12 is a cylinder made of, for example, aluminum or the like, and the pressure roller 14 is made of rubber or the like having no heat source. Further, the temperature sensor 71 and the A / D converter 61 constitute the temperature measuring means 15.

Further, the CPU and the program 60 include a print sequence control unit 65, a target temperature selection / drive instruction unit 66, a heater ON / OFF control unit 67, a temperature comparison unit 68, an initial operation required detection unit 69, and a job. Counter 70, print start detection unit 76, print command issue detection unit 7
7, a recording medium passage detection unit 78, and an idling state setting unit 79.

The print sequence control section 65 controls the sequence of printing operations. The target temperature selection / drive instructing unit 66 selects a target temperature to be achieved based on the comparison result or instruction of the temperature comparing unit 68 for the temperature measured by the temperature sensor 71, or issues an instruction to drive the target temperature. It is something to do.

The heater ON / OFF control unit 67 drives the halogen lamp 13 which is the heat source of the heat roller 12 based on the temperature measured by the temperature sensor 71 so as to achieve the instructed target temperature. 62
On / off control (voltage application interruption control) of application (ON) and interruption (OFF) of an AC voltage is performed with respect to.
The temperature comparison unit 68 compares the temperature measured by the temperature sensor 71 with the target temperature.

When the initial operation is required, the detecting unit 69 opens and closes the apparatus cover which can be opened and closed by turning on the apparatus power, removing a jam of the medium with the apparatus turned on, and replacing consumables, or The detection is performed when an initial operation such as reception of a device reset signal from a print data transmission source (host) such as a computer or a word processor is required.

The job counter 70 is rotated and started to start printing from the state of waiting for printing when the photosensitive drum 31 which is the latent image holding member is stopped, and executes the printing.
The operation until the photosensitive drum 31 is stopped due to circumstances such as interruption of print data is counted as one unit of job. For example, if one page is printed and the photosensitive drum 31 is stopped, it is counted as 1Job, and if five pages are printed continuously and the photosensitive drum 31 is stopped, this is also counted as 1Job.

The print start-up time detection unit 76 detects the print start-up time when the print operation is started by the print command in the idling state after completing the initial operation or after completing the print operation. The print command issuance detection unit 77
The issuance of a print command from the host 46 or the like is detected. The recording medium passage detection unit 78 detects whether or not a sheet, which is a recording medium, has passed through the fixing device 11 by a sheet discharge sensor (not shown).

If the next print command is not issued during printing, the idling state setting unit 79 selects the target temperature when the recording medium passage detecting unit 78 detects passage of the recording medium. The drive instruction unit 66 is immediately instructed to set the target temperature in the idling state (waiting for printing).

4): Description of print start control temperature In order to keep the temperature of the pressure roller within the required range, the control temperature of the heat roller is switched according to the temperature of the pressure roller. However, since no temperature sensor is attached to the pressure roller, the range of the pressure roller temperature is predicted from the form of the print job.

When the number of print jobs is small, the pressure roller is not sufficiently warm, so the control temperature of the heat roller is set to a high temperature. When the number of print jobs is large, the pressure roller is warm, so the heat roller is controlled. Try to set the temperature lower.

Therefore, a control temperature group prepared in advance is selected according to the count value of the job counter 70. Further, the counted number of jobs can be held in a storage area such as a memory, and as the storage area, one that can hold the storage even after the power of the device is turned off can be used. The number of jobs can be stored in a storage area that disappears after the power of the apparatus is turned off and a storage area that can retain the storage even after the power of the apparatus is turned off.

Further, when the apparatus performs an initial operation and the temperature of the heat roller surface is higher than a predetermined temperature, the printing job is retained even after the apparatus power is turned off.
The b number (job count value) can be read into the job counter 70 as an initial value. Further, when the apparatus performs the initial operation and the temperature of the heat roller surface is lower than the predetermined temperature, the job counter 70 can be read with the initial value as “0”.

Although it is easy to attach a temperature sensor to the pressure roller here, it is not attached in consideration of troubles such as attachment and cost increase. 5): Description of fixing ratio / correct curl FIG. 5 is an explanatory diagram of the pressure roller temperature. In FIG.
After the initial operation shown by, intermittent printing is performed 6 times (~
) Pressure roller 1 which is the backup roller when
4 shows the temperature change. In this way, the temperature of the pressure roller rises when the printing start by the intermittent printing is repeated.

When the temperature of the pressure roller is increased more than necessary, the fixing rate is necessary and sufficient, but there are problems such as the positive curl of the medium becoming larger than the permissible value and the wrinkling of the medium easily occurring. Get off. Therefore, the heat roller 12
It is necessary to keep the halogen lamp 13 on as much as possible except when necessary to suppress the temperature rise of the pressure roller.

In order to secure the fixing rate, not only the temperature of the heat roller 12 detected by the temperature sensor 71 such as a thermistor, but also the halogen lamp 13 which is a heat source when the medium passes.
It is important that is lit (detailed in Figure 8),
The fixing rate can be improved by devising the lighting timing.

FIG. 6 is an explanatory diagram of the relationship between the fixing ratio / normal curl and the heat roller temperature / pressure roller temperature. In FIG. 6, the fixing ratio / positive curl is determined by the heat roller temperature and the pressure roller temperature. The fixing rate improves as the heat roller temperature and the pressure roller temperature increase. The positive curl increases when the temperature of the pressure roller rises more than necessary. It was found that the temperature of the heat roller is determined by the surface temperature detected by the temperature sensor 71 and the lighting of the halogen lamp 13, which is a heat source.

FIG. 7 is an explanatory diagram of the fixing device control temperature. In FIG. 7, in the case of the heat roller temperature (output of the temperature sensor) initiative, when the heat roller temperature (output of the temperature sensor) and the pressure roller temperature are used, the heat roller temperature (output of the temperature sensor), the pressure roller temperature, and the halogen. When the lamp 13 is turned on, the change in the fixing rate depending on the control temperature of the fixing device is shown.

As shown in FIG. 7, the fixing ratio can be improved by heating the temperature of the heat roller, the temperature of the pressure roller, and turning on the halogen lamp 13. That is, in order to obtain the required fixing rate α, the halogen lamp 1 is adjusted in accordance with the paper (medium) entry.
By controlling the lighting timing of No. 3 and turning on the halogen lamp 13 when the paper passes, the control temperature of the fixing device can be lowered.

Therefore, by (1) suppressing the temperature rise of the pressure roller due to the decrease of the control temperature, and (2) controlling the lighting timing of the halogen lamp 13 and the paper entry timing, the halogen lamp 13 at unnecessary timing. Can be turned off.

Due to the effects of (1) and (2), the rise of the pressure roller temperature can be suppressed and the control temperature can be lowered, so that the positive curl can be reduced. 6): Description of heat roller temperature at which fixing is possible FIG. 8 is an explanatory diagram of heat roller temperature at which fixing is possible. FIG. 8 shows qualitative relations regarding the heat roller temperature at which fixing is possible, such as turning on / off the halogen lamp, the heat roller temperature in terms of the output of the temperature sensor, and the medium entry timing. The heat roller temperature rises when the halogen lamp 13 is turned on, and changes after passing the peak after the lamp is turned off. The thick line portion of this change is the fixing possible temperature.

At the following two medium entry timings shown in FIG. 8, there is a difference in heat roller temperature at which fixing is possible, and it was found that fixing can be performed at a lower temperature.
It is presumed that this is mainly due to overshoot that cannot be detected by the thermistor element.

When the halogen lamp 13 is on and the output of the temperature sensor is rising When the halogen lamp 13 is off and the output of the temperature sensor is falling For this reason, it is possible to fix the medium at a lower temperature. Since it is advantageous because the positive curl can be reduced,
Halogen lamp 1 considering the heat roller temperature at the time of receiving the print command so that fixing is performed at regular timing.
The control for shifting the lighting command of 3 is performed.

As described above, by devising the lighting timing by making the lighting command independent from the printing command, even if the heat roller temperature varies at the time of receiving the printing command, it is always possible to obtain the same result as shown in FIG.
The control is performed so that the fixing is performed at the most advantageous and reliable timing shown in.

7): Description of continuous printing During continuous printing, the temperature of the pressure roller decreases, and in particular, when the medium absorbs moisture, reverse curl occurs. In order to prevent this occurrence, the print end operation and the print start operation are set during continuous printing according to user settings.

As a result, a continuous sheet number counter or the like is provided,
A rotation start operation for starting printing is executed every predetermined number of sheets (for example, 5 sheets) during continuous printing. Therefore, the pressure roller temperature can be raised every time a predetermined number of sheets are printed.
As a result, it is possible to suppress the occurrence of reverse curl even with a medium that has absorbed moisture.

8): Description of Pressure Roller Temperature, Fixability and Curl Characteristic FIG. 9 is an explanatory view of the pressure roller temperature, fixability and curl characteristic. The figure shows the time course of the temperature of the pressure roller after the power supply to the device familiar with room temperature is turned on. The conventional method and the method of the present invention are all
Printing is started after about 5 minutes have passed (the initial operation ends during this time).

The conventional method shows a case where the intermittent printing, which is a general method of using a printer, in which 1 to 5 sheets are printed per 1 job, is repeated. In this case, as the printing is repeated, the pressure roller rises and the amount of positive curl increases.

The method of the present invention shows the case where the intermittent printing of printing 1 to 5 sheets per 1 Job, which is a general method of using a printer, is repeated. In this case, even if the printing is repeated, the pressure roller is used. Does not rise more than necessary.

The method of the present invention shows a temperature change curve when continuous printing with a short inter-medium distance is performed after repeating intermittent printing of printing 1 to 5 sheets per 1 Job which is a general printer usage method. ing. In this case, if continuous printing is continued, the temperature of the pressure roller decreases, and if the medium absorbs moisture, the amount of reverse curl increases.

The method of the present invention shows a temperature change curve when continuous printing with a short distance between the mediums from the cold start is performed. In this case, the temperature of the pressure roller does not rise so much and the medium absorbs moisture. If so, the amount of reverse curl increases.

As described above, according to the method of the present invention, the fixing failure does not occur, but the amount of reverse curl increases when the medium absorbs moisture. In order to prevent the amount of reverse curl from increasing, a continuous sheet number counter is provided during continuous printing according to a user setting (reverse curl mode) so that a print end operation and a print start operation are performed for each appropriate number of sheets. To do.

9): Description of control temperature specifications FIG. 10 is an explanatory diagram of control temperature specifications. FIG. 10 shows an example of the control temperature specifications, and the peripheral speed when the photosensitive drum rotates is 90 mm / s. In the standard mode, when the device performs the initial operation, when the fixing device (heat roller temperature) is a low temperature (Cold) of 100 ° C. or less, the initial temperature (1) is set to 2 as the control temperature of the heat roller.
The temperature is set to 00 ° C, and when heating (Warm) above 100 ° C, the initial temperature (2) is set to 145 ° C.

When the device is in the print standby mode and the job counter (J.C.) is "10" or less, the standby (Stan
d-by) The control temperature of the heat roller is 16 as the temperature (1).
Set to 0 ° C and the job counter (JC) is "11".
In the above cases, the control temperature of the heat roller is set to 145 ° C. as the standby (Stand-by) temperature (2).

At the time of printing start, when the job counter (J.C.) is "1", the control temperature of the heat roller is set as the print start control temperature (1) according to the heat roller temperature at the time of receiving the print command. Set to 185 ° C or 182 ° C. When the job counter (J.C.) is "2" to "10", the control temperature of the heat roller is set to 18 depending on the heat roller temperature when the print command is received as the print start control temperature (2).
Set to 0 ° C or 177 ° C. When the job counter (JC) is "11", the print start control temperature (3)
As, the control temperature of the heat roller is set to 173 ° C. or 170 ° C. according to the heat roller temperature at the time of receiving the print command. When the job counter (J.C.) is 12 or more, the print start control temperature (4) is set to 165 ° C. or 162 ° C. depending on the heat roller temperature when the print command is received. Set to.

In the case of continuous printing, when the job counter (JC) is "10" or less, the control temperature of the heat roller is set to 190 ° C as the continuous printing control temperature (1), and the job counter is set. When (J.C) is "11" or more, the control temperature of the heat roller is set to 185 ° C as the control temperature (2) during continuous printing. Also, both sides (Duplex)
The control temperature during continuous printing is 182 ° C, 177 ° C, 173 ° C / depending on the count value of the job counter (JC).
It is set to either 176 ° C or 162 ° C / 165 ° C. In addition, 173 ° C / 176 ° C and 162 ° C / 1
The fact that there are two set temperatures at 65 ° C indicates switching between the front and back sides of the paper.

The heating time (WUT: warm-up time) is as follows in the case of a Simplex machine (single-sided printing machine).
It takes 60 seconds, and in the case of a Duplex machine (double-sided printing machine), it takes 90 seconds. Also, the first print time (FP
T) is 12 seconds when the print density is 400 dpi or less and 15 seconds when the print density is 480 dpi or more.

In the thick paper mode, in the case of automatic paper feeding (MFF) including postcards, the control temperature of the heat roller is 195 ° C.
In the case of manual insertion including a postcard, the control temperature of the heat roller is set to 195 ° C.

10): Flowchart Explanation of Temperature Control of Fixing Device FIGS. 11 to 24 are flow charts of temperature control of the fixing device. Hereinafter, description will be given based on FIGS. 11 to 24.

(A) Description of Initial Operation FIG. 11 is a processing flowchart of the initial operation.
Hereinafter, description will be given according to the processing S11 to processing S33 of FIG.

S11: In the temperature comparison unit 68, the initial operation required time detection unit 69 causes the device cover opening / closing operation (Cover
Open / Close), power-on of the device (Power On), or device reset signal (Interface Reset) from a print data source such as a computer or word processor.
The surface temperature (TH) of the heat roller 12 measured in 1 is 1
It is determined whether the temperature is 00 ° C or lower. If the surface temperature (TH) of the heat roller 12 is 100 ° C. or lower in this determination, the process proceeds to step S12. If it is not 100 ° C. or lower, the process proceeds to step S26.

S12: Target temperature selection / drive instruction section 66
Resets the job counter 70 (job count value Jn = 0), and proceeds to processing S13 (cold start). S13: The target temperature selection / drive instruction unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 200 ° C. (TH = 200
C.) and the heater ON / OFF controller 67 controls the halogen lamp 13 which is the heat source of the heat roller 12.
Is turned on and the process proceeds to step S14.

S14: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 8 in the temperature comparison unit 68.
When the temperature exceeds 0 ° C, the process proceeds to step S15. S15: The target temperature selection / drive instructing unit 66 instructs the print sequence control unit 65 to rotate the fixing device, and the process S1
Go to 6.

S16: The print sequence control unit 65 rotates the fixing device for 45 seconds, and then proceeds to processing S17. S17: The printer device (CPU) outputs a printer ready signal in a printable state, and moves to processing S18.

S18: It is determined whether or not the print command is detected by the print command issuance detection unit 77 before the completion of the initial operation at the cold start. If the print command is detected in this determination, the process proceeds to step S19. If the print command is not detected, the process proceeds to step S20.

S19: The printer device judges whether the mode is the thick paper mode. If the determination is in the thick paper mode, the process S
161 (FIG. 22), and if it is not the thick paper mode, the process proceeds to step S41 (FIG. 12).

S20: If the print command is not detected in the determination of the process S19, the target temperature selection / drive instruction unit 6
6 is the control temperature of the surface temperature of the heat roller 12 is 160
The temperature is set to ° C (TH = 160 ° C), and the process proceeds to step S21.

S21: It is determined whether the print command issuance detection unit 77 has detected a print command. If a print command is detected in this determination, the process proceeds to step S19, and if
If the print command is not detected, the process proceeds to step S22.

S22: The printer device determines whether it is in the energy saving mode. If the energy saving mode is determined by this determination, the process proceeds to step S23. If the energy saving mode is not determined, the process returns to step S20.

S23: The printer device determines whether 30 minutes have elapsed after the printing operation (in this case, the initial operation) is completed. If 30 minutes have elapsed in this determination, the process proceeds to step S24, and if 30 minutes has not elapsed,
It returns to process S20.

S24: Target temperature selection / drive instruction section 66
Causes the heater ON / OFF control unit 67 to turn off the halogen lamp 13 which is a heat source (sleep: TH off), and proceeds to the processing S25.

S25: The print command issuance detection unit 77 waits until the next print command is detected, and when the print command is detected, the process returns to step S11. S26: If it is determined in step S11 that the temperature is not lower than 100 ° C., the target temperature selection / drive instructing unit 66 causes the job counter 70 that is held in the memory or the like even after the power supply to the apparatus is cut off.
The value of is continuously counted up, and the process proceeds to step S27 (warm start).

S27: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 145 °
C (TH = 145 ° C) and heater ON / OF
The halogen lamp 13 that is the heat source of the heat roller 12 is turned on (lighted) by the F control unit 67, and the process proceeds to step S28.

S28: Target temperature selection / drive instruction section 66
Instructs the print sequence controller 65 to rotate the fixing device, and then proceeds to step S29. S29: The print sequence control unit 65 rotates the fixing device for 11 seconds, and proceeds to processing S30.

S30: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 1 in the temperature comparison unit 68.
When the temperature reaches 45 ° C, the process proceeds to step S31. S31: The printer device outputs a printer ready signal in a printable state and moves to processing S32.

S32: It is judged whether or not the print command is detected by the print command issuance detection unit 77 before the completion of the initial operation at the warm start. If the print command is detected in this determination, the process proceeds to step S33. If the print command is not detected, the process proceeds to step S61 (FIG. 14).

S33: Target temperature selection / drive instruction section 66
Indicates that the count value (Jn) of the job counter 70 is "10"
Determine if it is greater than. If the count value is greater than "10" in this determination, the process proceeds to step S61 (FIG. 14). If it is not greater than "10", the process step S71 is performed.
(Fig. 15).

(B) Explanation of control temperature timing when the number of jobs is "1" FIG. 12 is a control temperature timing processing flowchart (Job
(When the number is 1). Hereinafter, description will be given according to the processing S41 to processing S49 of the flowchart of FIG.

S41: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 1 in the temperature comparison unit 68.
It is determined whether the temperature is 72 ° C or lower. If the surface temperature (TH) of the heat roller 12 is 172 ° C. or lower in this determination, the process proceeds to step S42. If it is not 172 ° C. or lower, the process proceeds to step S43.

S42: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 185 °
Set to C (TH: 185 ° C) and turn heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S51 (see FIG. 1).
Move on to 3). Here, the duty is a ratio of being turned on when the halogen lamp 13 is driven not intermittently but intermittently (on / off). For example, rated 800W
When the halogen lamp 13 is driven at a duty of 60%, the output becomes substantially 480W.

S43: If the surface temperature of the heat roller 12 is not 172 ° C. or lower in the judgment of the step S41, the target temperature selection / drive instructing unit 66 causes the temperature comparing unit 68 to determine that the surface temperature of the heat roller 12 is 182 ° C. Judge whether it is C or less. If the surface temperature (TH) of the heat roller 12 is 182 ° C. or lower in this determination, the process proceeds to step S44. If it is not 182 ° C. or lower, the process proceeds to step S47.

S44: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 160 °
By setting C (TH: 160 ° C), the heater is turned on /
The OFF control unit 67 prohibits the lighting of the halogen lamp 13, and the process proceeds to step S45.

S45: Target temperature selection / drive instruction section 66
Starts the drum motor that drives the photoconductor drum 31, and after 0.5 second has elapsed, moves to step S46. When the photosensitive drum 31 rotates, the heat roller 12 and the like also rotate at the same time.

S46: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 182 °
C (TH: 182 ° C) and heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S51 (see FIG. 1).
Move on to 3).

S47: When the surface temperature of the heat roller 12 is not 182 ° C. or lower in the judgment of the process S43, the target temperature selection / drive instructing unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 160 ° C. ( TH: 160 ° C.), the heater ON / OFF control unit 67 prohibits lighting of the halogen lamp 13, and the process proceeds to step S48.

S48: Target temperature selection / drive instruction section 66
Waits for the registration motor that drives the registration roller 35 to start, and when the registration motor starts, the process proceeds to step S49.

S49: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 182 °
C (TH: 182 ° C) and heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S51 (see FIG. 1).
Move on to 3).

As described above, when the surface temperature of the heat roller 12 is low (172 ° C. or lower), the halogen lamp 13 immediately turns on the halogen lamp 13 and the surface temperature of the heat roller 12 is medium (172 ° C. or higher). At 182 ° C or less)
In the case of, the drum motor is started 0.5 seconds later, and if the surface temperature of the heat roller 12 is high (182 ° C. or higher), the registration motor, which is the latest timing, is turned on at the start.

(C) Description of Print Execution Processing for Number of Jobs "1" FIG. 13 is a flowchart of print execution processing for the number of jobs "1". Hereinafter, processing S51 to the processing in the flowchart of FIG.
It will be described according to the process S59.

S51: The print sequence controller 65 performs a predetermined print operation, and proceeds to the processing S52. S52: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected by this determination, the process proceeds to step S53, and if not detected, the process proceeds to step S61 (FIG. 14).

S53: Target temperature selection / drive instruction section 66
Determines whether it is Duplex (duplex) continuous printing.
In the case of Duplex continuous printing in this determination, the process S54
If no Duplex continuous printing is performed, the process proceeds to step S56.

S54: Target temperature selection / drive instruction section 66
Indicates that the count value of the job counter (JC) 70 is "1.
It is determined whether it is smaller than 1 ”. If the count value is smaller than "11" in this determination, the process proceeds to step S55. If it is not smaller than "11", the process proceeds to step S57.

S55: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 177 °
Set to C (TH: 177 ° C) and turn heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process returns to step S51.

S56: Duplex in the determination of S53
If it is not continuous printing, the target temperature selection / drive instruction unit 66
Indicates that the count value of the job counter (JC) 70 is "1.
It is determined whether it is smaller than 1 ”. If the count value is smaller than “11” in this determination, the process S111 (see FIG.
If it is not smaller than “11”, the process proceeds to step S121 (FIG. 19).

S57: When the count value of the job counter (J.C.) 70 is not smaller than "11" in the judgment of S54, the target temperature selection / drive instructing unit 66 causes the job counter (J.C.) 70 It is determined whether the count value is smaller than "12". The count value is "12" in this judgment
If it is smaller, the process proceeds to step S58, and if "12".
If it is not smaller, the process proceeds to step S59.

S58: Target temperature selection / drive instruction section 66
The control temperature of the surface temperature of the heat roller 12 is 173 ° C. for the front side printing of the paper and 176 ° C. for the back side printing.
C (TH: 173.degree. C./176.degree. C.) is set, and the heater ON / OFF control section 67 drives the halogen lamp 13 to light with a duty of 60% (Duty: 60%), and the process returns to step S51.

S59: If the count value of the job counter (JC) 70 is not smaller than "12" in the determination of S57, the target temperature selection / drive instructing section 66 causes the surface temperature of the heat roller 12 to be the control temperature. Is 162 ° C for front side printing and 165 ° C for back side printing (TH: 16
2 ° C / 165 ° C) and heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process returns to step S51.

(D) Description of Job Count Value Judgment Processing FIG. 14 is a flowchart of the job count value judgment processing. Hereinafter, description will be given according to the processing S61 to processing S65 of the flowchart of FIG.

S61: Target temperature selection / drive instruction section 66
Indicates that the count value (Jn) of the job counter 70 is "10"
Determine if it is greater than. If the count value is greater than "10" in this determination, the process proceeds to step S99 (FIG. 17). If it is not greater than "10", the process step S62 is performed.
Move on to

S62: Target temperature selection / drive instruction section 66
Counts up the count value of the job counter (J.C.) 70 and moves to process S63 (the number of jobs "2"-
"10" print standby).

S63: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 160 °
C (TH = 160 ° C.) is set, and the process proceeds to step S64. S64: The print command issuance detection unit 77 determines whether the print command data is received. If the print command data is received in this determination, the process proceeds to step S65. If not, the process returns to step S63.

S65: The printer device judges whether the mode is the thick paper mode. If the determination is in the thick paper mode, the process S
161 (FIG. 22), and if it is not the thick paper mode, the process proceeds to step S71 (FIG. 15).

(E) Description of control temperature timing when the number of jobs is “2” to “10” FIG. 15 is a control temperature timing processing flowchart (Job
If the number is 2 to 10). Hereinafter, description will be given according to the processing S71 to processing S79 in the flowchart of FIG.

S71: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 1 in the temperature comparison unit 68.
It is determined whether the temperature is 67 ° C or lower. If the surface temperature (TH) of the heat roller 12 is 167 ° C. or lower in this determination, the process proceeds to step S72. If it is not 167 ° C. or lower, the process proceeds to step S73.

S72: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 180 °
Set to C (TH: 180 ° C) and turn heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S81 (see FIG. 1).
Move to 6).

S73: If the surface temperature of the heat roller 12 is not 167 ° C. or lower in the judgment of the process S71, the target temperature selection / drive instructing unit 66 causes the temperature comparing unit 68 to determine that the surface temperature of the heat roller 12 is 177 ° C. Judge whether it is C or less. If the surface temperature (TH) of the heat roller 12 is 177 ° C. or lower in this determination, the process proceeds to step S74. If it is not 177 ° C. or lower, the process proceeds to step S77.

S74: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 160 °
By setting C (TH: 160 ° C), the heater is turned on /
The OFF control unit 67 prohibits lighting of the halogen lamp 13, and the process proceeds to step S75.

S75: Target temperature selection / drive instruction section 66
Starts the drum motor for driving the photosensitive drum 31, and after 0.5 second has elapsed, moves to the processing S76. S76: The target temperature selection / drive instruction unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 177 ° C. (TH: 177
Temperature) and the heater ON / OFF control unit 67 controls the halogen lamp 13 to have a duty of 60% (Duty: 6).
The lighting is driven at 0%), and the process proceeds to step S81 (FIG. 16).

S77: When the surface temperature of the heat roller 12 is not 177 ° C. or lower in the judgment of the process S73, the target temperature selection / drive instructing unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 160 ° C. ( TH: 160 ° C.), the heater ON / OFF control unit 67 prohibits the halogen lamp 13 from turning on, and the process proceeds to step S78.

S78: Target temperature selection / drive instruction section 66
Waits for the registration motor that drives the registration roller 35 to start, and if the registration motor starts, the process proceeds to step S79.

S79: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 177 °
Set to C (TH: 177 ° C) and turn heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S81 (see FIG. 1).
Move to 6).

(F) Description of the print start processing when the number of jobs is “2” to “10” FIG. 16 is a print start processing flowchart (the number of jobs is 2 to 1).
0)). Hereinafter, a description will be given according to the processing S81 to processing S89 of the flowchart of FIG.

S81: The print sequence controller 65 performs a predetermined print operation, and proceeds to process S82. S82: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected by this determination, the process proceeds to step S83, and if not detected, the process proceeds to step S61 (FIG. 14).

S83: Target temperature selection / drive instruction section 66
Determines whether it is Duplex (duplex) continuous printing.
In the case of Duplex continuous printing in this determination, processing S84
If no Duplex continuous printing is performed, the process proceeds to step S86.

S84: Target temperature selection / drive instruction section 66
Indicates that the count value of the job counter (JC) 70 is "1.
It is determined whether it is smaller than 1 ”. If the count value is smaller than "11" in this determination, the process proceeds to step S85, and if it is not smaller than "11", the process proceeds to step S87.

S85: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 177 °
Set to C (TH: 177 ° C) and turn heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process returns to step S81.

S86: Duplex in the judgment of S83
If it is not continuous printing, the target temperature selection / drive instruction unit 66
Indicates that the count value of the job counter (JC) 70 is "1.
It is determined whether it is smaller than 1 ”. If the count value is smaller than “11” in this determination, the process S111 (see FIG.
If it is not smaller than “11”, the process proceeds to step S121 (FIG. 19).

S87: If the count value of the job counter (J.C.) 70 is not smaller than "11" in the determination of S84, the target temperature selection / drive instructing unit 66 causes the job counter (J.C.) 70 It is determined whether the count value is smaller than "12". The count value is "12" in this judgment
If it is smaller, the process moves to S88, and if it is "12".
If it is not smaller, the process proceeds to step S89.

S88: Target temperature selection / drive instruction section 66
The control temperature of the surface temperature of the heat roller 12 is 173 ° C. for the front side printing of the paper and 176 ° C. for the back side printing.
The temperature is set to C (TH: 173 ° C./176° C.), and the heater ON / OFF control unit 67 drives the halogen lamp 13 to light with a duty of 60% (Duty: 60%), and the process returns to step S81.

S89: If the count value of the job counter (J.C.) 70 is not smaller than "12" in the judgment of S87, the target temperature selection / drive instructing section 66 causes the surface temperature of the heat roller 12 to be the control temperature. Is 162 ° C for front side printing and 165 ° C for back side printing (TH: 16
2 ° C / 165 ° C) and heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process returns to step S81.

(G) Description of Print Standby and Print Start Processing with Number of Jobs of "11" or More FIG. 17 is a print wait and print start processing flowchart (Jo
b is 11 or more). Hereinafter, description will be given according to the processing S91 to processing S101 of the flowchart of FIG.

S91: The print sequence controller 65 performs a predetermined print operation, and proceeds to the processing S92. S92: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected by this determination, the process proceeds to step S93, and if not detected, the process proceeds to step S95.

S93: Target temperature selection / drive instruction section 66
Determines whether it is Duplex continuous printing. If Duplex continuous printing is determined by this determination, the process proceeds to step S94,
If it is not Duplex continuous printing, step S12.
1 (FIG. 19).

S94: Target temperature selection / drive instruction section 66
The control temperature of the surface temperature of the heat roller 12 is 162 ° C. for the front side printing of the paper and 165 ° C. for the back side printing.
C (TH: 162 ° C / 165 ° C) is set, and the heater ON / OFF control unit 67 drives the halogen lamp 13 to light up with a duty of 60% (Duty: 60%), and the process returns to step S91.

S95: When the next print command is not detected in the determination of S92, the printer device determines whether it is in the energy saving mode. If the energy saving mode is determined by this determination, the process proceeds to step S96, and if not, the process proceeds to step S99.

S96: The printer device determines whether 30 minutes have elapsed after the printing operation is completed. 30 in this judgment
If the minutes have elapsed, the process proceeds to step S97. If the 30 minutes have not elapsed, the process proceeds to step S99.

S97: Target temperature selection / drive instruction section 66
Causes the heater ON / OFF control unit 67 to turn off the halogen lamp 13 which is a heat source (sleep: TH off), and proceeds to the processing S98.

S98: The print command issuance detection unit 77 waits until the next print command is detected, and when the print command is detected, the process returns to the process S11 (FIG. 11). S99: When the energy saving mode is not determined by the determination of the process S95 or when 30 minutes is not determined by the determination of the process S96, the target temperature selection / drive instruction unit 66 sets the control temperature of the surface temperature of the heat roller 12 to the control temperature. 145 ° C (TH = 1
45 ° C.) and the process proceeds to S100.

S100: The print command issuance detection unit 77 determines whether or not the print command data is received. If the print command data is received in this determination, the process proceeds to step S101, and if not received, the process returns to step S95.

S101: The printer device determines whether or not it is in the thick paper mode. If the determination is in the thick paper mode, the process proceeds to step S161 (FIG. 22). If the mode is not the thick sheet mode, the process proceeds to step S131 (FIG. 20).

(H) Description of Continuous Printing Process for Job Number "1" to "10" FIG.
0)). Hereinafter, description will be given according to the processing S111 to processing S116 of the flowchart of FIG.

S111: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 190 °
C (TH = 190 ° C.) is set, and the process proceeds to step S112. S112: The print sequence control unit 65 performs a predetermined printing operation, and proceeds to processing S113.

S113: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected in this determination, the process proceeds to step S114. If not, the process S6 is performed.
1 (FIG. 14).

S114: Target temperature selection / drive instruction section 66
Determines whether the reverse curl mode is set (ON). If the reverse curl mode is set in this determination, the process proceeds to step S115, and if not, the process returns to step S111.

S115: Target temperature selection / drive instruction section 66
Determines whether the count value (Lo) of the continuous number counter is larger than "4". The count value (L
If o) is larger than “4” (Lo> 4), processing S11
Move to 6 and, if it is not larger than "4", process S
Return to 111.

S116: Target temperature selection / drive instruction section 66
Performs a print end operation, further performs a stop (1 second) operation of the photosensitive drum 31, and then performs a start operation, and the process S
Return to 111.

(I) Description of Continuous Printing Process with Job Number "11" or More FIG. 19 is a continuous printing process flowchart (when the number of jobs is 11 or more). Hereinafter, a description will be given according to the processing S121 to processing S127 in the flowchart of FIG.

S121: The printer device determines whether or not it is in the thick paper mode. If the determination is in the thick paper mode, the process proceeds to step S161 (FIG. 22). If the mode is not the thick sheet mode, the process proceeds to step S122.

S122: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 185 °
C (TH = 185 ° C.) is set, and the process proceeds to step S123. S123: The print sequence control unit 65 performs a predetermined print operation, and proceeds to processing S124.

S124: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected in this determination, the process proceeds to step S125. If not, the process S6 is performed.
1 (FIG. 14).

S125: Target temperature selection / drive instruction section 66
Determines whether the reverse curl mode is set (ON). If the reverse curl mode is set in this determination, the process proceeds to step S126, and if not, the process returns to step S121.

S126: Target temperature selection / drive instruction section 66
Determines whether the count value (Lo) of the continuous number counter is larger than "4". The count value (L
If o) is larger than “4” (Lo> 4), processing S12
7. If it is not greater than "4", go to step S7.
Return to 121.

S127: Target temperature selection / drive instruction section 66
Performs a print end operation, further performs a stop (1 second) operation of the photosensitive drum 31, and then performs a start operation, and the process S
Return to 121.

(J) Description of Control Temperature Timing when Number of Jobs is "11" FIG. 20 is a control temperature timing processing flowchart (when the number of jobs is 11). Hereinafter, FIG.
The processing will be described according to the processing S131 to processing S141 of the flowchart.

S131: Target temperature selection / drive instruction section 66
Indicates that the count value (Jn) of the job counter 70 is "11".
Determine whether or not. If the count value is "11" in this determination, the process proceeds to step S132, and if it is not "11", the process proceeds to step S151 (FIG. 21).

S132: Target temperature selection / drive instruction section 66
Counts up the count value of the job counter (J.C.) 70, and moves to the processing S133. S133: The target temperature selection / drive instructing unit 66 determines whether the surface temperature of the heat roller 12 is 160 ° C. or less by the temperature comparing unit 68. Heat roller 1
If the surface temperature (TH) of 2 is 160 ° C. or lower, the process proceeds to step S134. If it is not 160 ° C. or lower, the process proceeds to step S135.

S134: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 by 173 °
Set to C (TH: 173 ° C) and turn heater on / of
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S91 (FIG. 1) is performed.
Move on to 7).

S135: If the surface temperature of the heat roller 12 is not lower than 160 ° C. in the judgment of the processing S133, the target temperature selection / drive instructing section 66 causes the temperature comparing section 68 to operate.
Then, it is determined whether the surface temperature of the heat roller 12 is 170 ° C. or lower. If the surface temperature (TH) of the heat roller 12 is 170 ° C. or lower in this determination, the process S1
36, and if 170 ° C. or less, move to processing S139.

S136: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 153 °
By setting C (TH: 153 ° C), the heater is turned on /
The OFF control unit 67 prohibits lighting of the halogen lamp 13, and the process proceeds to step S137.

S137: Target temperature selection / drive instruction section 66
Starts the drum motor that drives the photoconductor drum 31, and after 0.5 second has elapsed, moves to step S138. S138: The target temperature selection / drive instruction unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 170 ° C. (TH: 17
0 ° C.) and the heater ON / OFF control unit 67
The halogen lamp 13 with a duty of 60% (Duty:
Lighting is driven at 60%), and the process proceeds to step S91 (FIG. 17).

S139: If the surface temperature of the heat roller 12 is not lower than 170 ° C. in the judgment of the process S135, the target temperature selection / drive instructing section 66 causes the heat roller 1
The control temperature of the surface temperature of 2 is 153 ° C (TH: 153 °
C), the heater ON / OFF control unit 67
The halogen lamp 13 is prohibited from being turned on by the step S14.
Move to 0.

S140: Target temperature selection / drive instruction section 66
Waits for the registration motor that drives the registration roller 35 to start, and if the registration motor starts, the process proceeds to step S141.

S141: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 170 °
Set to C (TH: 170 ° C) and turn heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S91 (FIG. 1) is performed.
Move on to 7).

(K) Description of control temperature timing when the number of jobs is “12” or more FIG. 21 is a control temperature timing processing flowchart (Job
If the number is 12 or more). Hereinafter, description will be given according to the processing S151 to processing S159 of the flowchart of FIG.

S151: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 1 in the temperature comparison unit 68.
It is determined whether the temperature is 52 ° C or lower. If the surface temperature (TH) of the heat roller 12 is 152 ° C. or lower in this determination, the process proceeds to step S152. If it is not 152 ° C. or lower, the process proceeds to step S153.

S152: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 165 °
C (TH: 165 ° C) and heater ON / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S91 (FIG. 1) is performed.
Move on to 7).

S153: If the surface temperature of the heat roller 12 is not lower than 152 ° C. in the judgment of the process S152, the target temperature selecting / driving instructing unit 66 causes the temperature comparing unit 68 to operate.
Then, it is determined whether the surface temperature of the heat roller 12 is 162 ° C. or lower. If the surface temperature (TH) of the heat roller 12 is 162 ° C. or lower in this determination, the process S1
The process moves to 54, and if it is not lower than 162 ° C., the process moves to S157.

S154: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 145 °
By setting C (TH: 145 ° C), heater ON /
The OFF control unit 67 prohibits lighting of the halogen lamp 13, and the process proceeds to step S155.

S155: Target temperature selection / drive instruction section 66
Starts the drum motor that drives the photoconductor drum 31, and after 0.5 second has elapsed, moves to step S156. S156: The target temperature selection / drive instruction unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 162 ° C. (TH: 16
2 ° C) and the heater ON / OFF control unit 67
The halogen lamp 13 with a duty of 60% (Duty:
Lighting is driven at 60%), and the process proceeds to step S91 (FIG. 17).

S157: When the surface temperature of the heat roller 12 is not lower than 162 ° C. in the judgment of the process S153, the target temperature selection / drive instructing section 66 causes the heat roller 1
The control temperature of the surface temperature of 2 is 145 ° C (TH: 145 °
C), the heater ON / OFF control unit 67
The halogen lamp 13 is prohibited from being turned on by the step S15.
Move to 8.

S158: Target temperature selection / drive instruction section 66
Waits for the registration motor that drives the registration roller 35 to start, and if the registration motor starts, the process proceeds to step S159.

S159: Target temperature selection / drive instruction section 66
Controls the surface temperature of the heat roller 12 to 162 °
Set to C (TH: 162 ° C) and turn on heater / OF
The F control unit 67 controls the duty of the halogen lamp 13 to 6
The lighting is driven at 0% (Duty: 60%), and the process S91 (FIG. 1) is performed.
Move on to 7).

(L) Description of Cardboard Mode Processing FIG. 22 is a flowchart of cardboard mode processing. Less than,
Processing steps S161 to S174 in the flowchart of FIG.
It will be described according to.

S161: The printer device determines whether the paper feed port is automatic paper feed (MFF) or manual insertion. If the sheet is automatically fed (MFF), the process proceeds to step S162. If the sheet is manually inserted, the process proceeds to step S169.

S162: The printer device determines whether the paper is a postcard. In the case of a postcard in this determination, processing S16
If it is not a postcard, the process proceeds to step S169. S163: The target temperature selection / drive instruction unit 66 sets the control temperature of the surface temperature of the heat roller 12 to 195 ° C. (TH = 19).
5 ° C) and the heater ON / OFF control unit 6
The halogen lamp 13 which is the heat source of the heat roller 12 is turned on (Heater On) by 7 to stop the rotation of the drum motor for driving the photosensitive drum 31, and the process S164 is performed.
Move on to

S164: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 1 in the temperature comparison unit 68.
It waits until it becomes higher than 65 ° C, and when it becomes higher than 165 ° C, it moves to the processing S165.

S165: The print sequence controller 65
The pick roller 36 that supplies the paper to the printer is started (Pick Start) to perform a predetermined printing operation, and the process S1 is performed.
Move to 66.

S166: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected in this determination, the process proceeds to step S167. If not, the process S6 is performed.
1 (FIG. 14).

S167: Target temperature selection / drive instruction section 66
Continuously sets the control temperature of the surface temperature of the heat roller 12 to 195 ° C. (TH = 195 ° C.), and turns on the halogen lamp 13 which is the heat source of the heat roller 12 by the heater ON / OFF control unit 67. (Heater On) and the process proceeds to step S168.

S168: The print sequence controller 65
The sheets are separated by 1.33 seconds or more, the pick roller 36 that feeds the sheets to the printer is started (Pick Start), a predetermined printing operation is performed, and the process returns to step S166.

S169: Target temperature selection / drive instruction section 66
If the determination in S161 is manual insertion,
When the determination of No. 2 is not a postcard, the control temperature of the surface temperature of the heat roller 12 is set to 195 ° C. (TH = 195 ° C.), and the heater ON / OFF control unit 67 sets the halogen as the heat source of the heat roller 12. Turn on the lamp 13 (He
(ater On) to stop the rotation of the drum motor that drives the photosensitive drum 31, and the process proceeds to step S170.

S170: Target temperature selection / drive instruction section 66
Indicates that the surface temperature of the heat roller 12 is 1 in the temperature comparison unit 68.
It waits until it becomes higher than 60 ° C, and when it becomes higher than 160 ° C, it moves to processing S171.

S171: The print sequence controller 65
The pick roller 36 that supplies the paper to the printer is started (Pick Start) to perform a predetermined printing operation, and the process S1 is performed.
Move on to 72.

S172: The print command issuance detection unit 77 determines whether or not the next print command is detected during the printing operation. If the next print command is detected in this determination, the process proceeds to step S173. If not, the process S6 is performed.
1 (FIG. 14).

S173: Target temperature selection / drive instruction section 66
Continuously sets the control temperature of the surface temperature of the heat roller 12 to 195 ° C. (TH = 195 ° C.), and turns on the halogen lamp 13 which is the heat source of the heat roller 12 by the heater ON / OFF control unit 67. (Heater On) and the process moves to S174.

S174: The print sequence controller 65
The sheets are separated by 1.33 seconds or more, the pick roller 36 that supplies the sheets to the printer is started (Pick Start), a predetermined printing operation is performed, and the process returns to step S172.

(M) Detailed description of copy (determination process at the time of printing end and continuation) FIG. 23 is a flowchart of the judgment process at the end of printing and continuation (details of part ◆ in FIGS. 13, 16 and 17). Less than,
Processing steps S181 to S186 in the flowchart of FIG.
It will be described according to.

S181: The print sequence controller 65
A predetermined printing operation is performed, and the process proceeds to step S182. S182: The print command issuance detection unit 77 causes the paper ejection sensor (fu
ser senser) determines whether the next print command is detected during the printing operation until the edge of the paper is detected as passing through the fixing device. If the next print command is detected by this determination (Yes), the process proceeds to the print continuation process, and if not detected, the process proceeds to step S183.

S183: Target temperature selection / drive instruction section 66
Is the control temperature of the surface temperature of the heat roller 12 is 145 °
By setting C (forced TH: 145 ° C), the heater O
The halogen lamp 13, which is the heat source of the heat roller 12, is forcibly turned off by the N / OFF control unit 67, and the process proceeds to step S184.

S184: The print command issuance detection unit 77 determines whether or not the next print command is detected. If the next print command is detected in this determination (Yes), the process proceeds to the print continuation process, and if not detected, the process proceeds to step S185.

S185: The printer device determines whether or not the issuance of the command for stopping the photosensitive drum 31 is detected. If the issuance of the command to stop the photosensitive drum 31 is detected in this determination, the process proceeds to step S186, and if
If it cannot be detected, the process returns to step S184.

S186: Idling state setting unit 79
Causes the printer device to shift to the standby state (Stand-by Mode). (N) Details of & Section (Details of Duplex Printing) FIG. 24 is a flowchart of detailed Duplex printing processing (details of & section in FIGS. 13, 16 and 17). Hereinafter, FIG.
The process will be described in accordance with processes S190 to S193 of the flowchart of FIG.

S190: Target temperature selection / drive instruction section 66
Counts up the count value of the job counter (J.C.) 70, and proceeds to processing S191. S191: The print sequence control unit 65 performs a predetermined printing operation, and proceeds to processing S192.

S192: Target temperature selection / drive instruction section 66
Is set to 145 ° C (forced TH: 145 ° C) for 2.2 seconds after controlling the surface temperature of the heat roller 12 after the discharge sensor detects that the edge of the paper has passed the fixing device. The heater ON / OFF control unit 67 forcibly turns off the halogen lamp 13, which is the heat source of the heat roller 12, and proceeds to step S193.

S193: Target temperature selection / drive instruction section 66
Prints the control temperature of the surface temperature of the heat roller 12 Jo
182 ° C or 177 ° C or 173 ° C depending on the number of b
/ 176 ° C or 162 ° C / 165 ° C (173 ° C
/ 176 ° C and 162 ° C / 165 ° C are switched between the front side and the back side of the paper) and the heater O is set.
The N / OFF control unit 67 lights the halogen lamp 13 with a duty of 60% (Duty: 60%).

[0220]

As described above, the present invention has the following effects. (1): The latent image holding member is stopped by the job counter, the printing is started from the waiting state for printing,
The operation from printing to the stop of the latent image holding member is counted as one job, and the temperature control unit controls the heat source according to the count value of the job counter. It can be easily estimated, and the required fixing ratio and a small curl amount can be obtained when the temperature of the pressure roller is low or high.

(2): The latent image holding member is stopped to start printing to start printing, the printing is executed, and the operation until the latent image holding member is stopped is 1
The temperature range of the pressure roller can be easily estimated due to the control method of the image forming apparatus in which the temperature control unit controls the heat source according to the counted number of jobs. It is possible to obtain a required fixing ratio and a small amount of positive curl when the temperature is low or high.

(3): Since the counted number of jobs is held in the storage area, the number of jobs can be easily read from the storage area when necessary. (4): Since the counted number of jobs is stored in the storage area that is retained even after the power is turned off, the temperature range of the pressure roller can be easily estimated even when the device is turned off and then turned on again. be able to.

(5): In order to change the control temperature set in the heat roller at the time of printing the first page for starting printing from the print waiting state in accordance with the number of jobs,
It is possible to obtain a required fixing ratio and a small amount of positive curl at the time of printing the first page.

(6): Since the control temperature to be changed according to the number of jobs is selected from the control temperature group prepared in advance, the control temperature can be easily set. (7): Since the actual control temperature and the heat source drive timing are determined from the control temperature group selected according to the temperature of the heat roller at the time of receiving the print command, finer control can be performed, which is reliable. It is possible to obtain a fixing ratio and a small amount of positive curl required for the above.

(8): Start printing from the print waiting state. Since the control temperature to be set to the heat roller when printing is continued after the first page is selected according to the number of jobs, print waiting is performed. Even if you continue printing after the first page that starts printing from the state of
A required fixing rate and a small amount of positive curl can be obtained.

(9): When executing the initial operation,
If the temperature of the heat roller is higher than the specified temperature, the number of jobs held even after the power is turned off is counted as the initial value.Therefore, the temperature of the fuser will drop too much after the power of the device is turned off. Even if the device power is turned on again when the power is off, the temperature range of the pressure roller can be easily estimated from the temperature of the heat roller and the number of jobs at that time, and the required fixing rate and a small amount of positive curl can be obtained. .

(10): When executing the initial operation, if the temperature of the heat roller is lower than the predetermined temperature, the initial value of the number of jobs is counted as zero. Even if the power of the device is turned on again when the temperature of the fixing device is sufficiently low, the temperature of the heat roller can be easily estimated from the temperature of the heat roller at that time, and the required fixing ratio and a small positive curl amount can be obtained. Obtainable.

(11) When the continuous printing of the hygroscopic medium is performed by the setting of the user or the like, in order to insert the printing end operation and the printing start operation during the continuous printing, the pressure roller is applied every predetermined number of sheets during the continuous printing. The temperature can be increased, and even if the medium absorbs moisture, reverse curl can be suppressed.

(12) Since the temperature control method of the image forming apparatus is used for the printer control method of the information processing system, the required fixing rate and the small amount of positive curl, and the required fixing rate during continuous printing are small. It is possible to obtain the printer of the information processing system having the reverse curl amount.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram of a printer device overview and a paper path route according to the embodiment.

FIG. 3 is a block diagram showing an outline of a printer engine in the embodiment.

FIG. 4 is a functional block diagram of a control system in the embodiment.

FIG. 5 is an explanatory diagram of a pressure roller temperature in the embodiment.

FIG. 6 is an explanatory diagram of a relationship between fixing ratio / normal curl and heat roller temperature / pressure roller temperature in the embodiment.

FIG. 7 is an explanatory diagram of a fixing device control temperature in the embodiment.

FIG. 8 is an explanatory diagram of a heat roller temperature at which fixing is possible in the embodiment.

FIG. 9 is an explanatory diagram of pressure roller temperature, fixing property and curl characteristic in the embodiment.

FIG. 10 is an explanatory diagram of control temperature specifications in the embodiment.

FIG. 11 is a processing flowchart of an initial operation in the embodiment.

FIG. 12 is a control temperature timing processing flowchart (when the number of jobs is 1) in the embodiment.

FIG. 13 is a print execution process flowchart of the number of jobs “1” according to the embodiment.

FIG. 14 is a flowchart of a job count value determination process according to the embodiment.

FIG. 15 is a control temperature timing processing flowchart (when the number of jobs is 2 to 10) in the embodiment.

FIG. 16 is a print start processing flowchart (when the number of jobs is 2 to 10) in the embodiment.

FIG. 17 is a flowchart of print standby and print start processing according to the embodiment (when the number of jobs is 11 or more).

FIG. 18 is a flowchart of a continuous printing process according to the embodiment (when the number of jobs is 1 to 10).

FIG. 19 is a flowchart of continuous printing processing according to the embodiment (when the number of jobs is 11 or more).

FIG. 20 is a control temperature timing processing flowchart (when the number of jobs is 11) in the embodiment.

FIG. 21 is a control temperature timing processing flowchart (when the number of jobs is 12 or more) in the embodiment.

FIG. 22 is a flowchart of thick paper mode processing according to the embodiment.

FIG. 23 is a flowchart of a determination process when printing is completed or continued in the embodiment.

FIG. 24 is a flowchart of detailed Duplex printing processing according to the embodiment.

FIG. 25 is an explanatory diagram of a conventional example.

FIG. 26 is an explanatory diagram of switching of fixing temperature in a conventional example.

FIG. 27 is an explanatory diagram of the pressure roller temperature during intermittent printing in the conventional example.

FIG. 28 is an explanatory diagram of a conventional printing paper curl.

[Explanation of symbols]

 11 Fixing Device 12 Heat Roller 13 Heat Source 14 Pressure Roller 15a Temperature Detection Means 50a Temperature Control Means 70 Job Counter

Claims (12)

[Claims] 1. A heat roller having a built-in heat source, a temperature detecting means for detecting the temperature of the heat roller, a pressure roller for pressing a recording medium having a developer transferred from a latent image holding member against the heat roller, A temperature control unit that controls the heat source, and the latent image holding member is started to start printing from a waiting state in which printing is stopped, until printing is performed and the latent image holding member is stopped. An image forming apparatus, wherein the temperature control unit controls the heat source according to a count value of the job counter. 2. A heat roller having a built-in heat source, a temperature detecting means for detecting the temperature of the heat roller, a pressure roller for pressing the recording medium having the developer transferred from the latent image holding member against the heat roller. In a method of controlling an image forming apparatus including a temperature control unit that controls the heat source, the latent image holding member is activated to start printing from a print standby state, and print is executed. The operation until the latent image holding member is stopped is counted as one job, and the temperature control means controls the heat source according to the counted number of jobs. . 3. The method of controlling an image forming apparatus according to claim 2, wherein the counted number of jobs is held in a storage area. 4. The method of controlling an image forming apparatus according to claim 3, wherein the counted number of jobs is stored in a storage area which is retained even after the power is turned off. 5. The control temperature set in the heat roller at the time of printing the first page of the print starting from the print waiting state is changed according to the number of jobs. 5. The method for controlling the image forming apparatus according to any one of 4 above. 6. The method of controlling an image forming apparatus according to claim 5, wherein the control temperature changed according to the number of jobs is selected from a control temperature group prepared in advance. 7. The actual control temperature and the drive timing of the heat source are determined from the selected control temperature group according to the temperature of the heat roller at the time of receiving a print command. 6. A method for controlling an image forming apparatus according to item 6. 8. A control temperature to be set in the heat roller when printing is continued from the first page where printing is started from a print waiting state is selected according to the number of jobs. The method for controlling an image forming apparatus according to claim 2, 9. When the power is turned on, when the cover is opened or closed, or when the initial operation is executed by a reset signal, if the temperature of the heat roller is higher than a predetermined temperature, it is retained even after the power is turned off. The method of controlling an image forming apparatus according to claim 2, wherein the number of jobs is counted as an initial value. 10. The initial value of the number of jobs is set to zero when the temperature of the heat roller is lower than a predetermined temperature when the power is turned on, when the cover is opened and closed, or when the initial operation is performed by a reset signal. The method for controlling an image forming apparatus according to claim 2, wherein the control is performed as follows. 11. A heat roller having a built-in heat source, a temperature detecting means for detecting the temperature of the heat roller, a pressure roller for pressing the recording medium having the developer transferred from the latent image holding member against the heat roller, In the control method of the image forming apparatus including the temperature control means for controlling the heat source, when performing continuous printing, an image characterized by including a print end operation and a print start operation during the continuous printing Control method of forming apparatus. 12. A method for controlling an image forming apparatus according to claim 2, which is used for a method for controlling a printer of an information processing system.