JPH09274408A - Temperature controller for heating roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature controller for a heating roll capable of preventing the abnormal high temp. of the heating roll, even if an engine is stopped to stop the supply of power to a heat source. SOLUTION: The surface temp. of the heating roll 9 is measured by three thermistors 14a-14c arranged side by side in an axial direction in the vicinity of the surface of the heating roll 9. An engine control part 15 detects a temperature distribution on the surface of the heating roll 9, based on the temp. measured by these thermistors 14a-14c. The engine control part 15 rotates cooling fans 12a-12c and 13a-13c provided to correspond to the thermistors 14a-14c respectively, so as to make the surface temperature of the heating roll 9 uniform over the whole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for a heat roll used in an electrophotographic apparatus, and more particularly to a temperature control device for a heat roll for blowing cooling air to the heat roll to cool it.

[0002]

2. Description of the Related Art An electrophotographic apparatus used in a copying machine, a printer, or a facsimile transfers a toner image formed on a transfer drum onto a recording sheet and heats the recording sheet on which the toner image is transferred with a heat roll and a press. The toner image is fixed by passing it through a roll. Since this heat roll has a heat source such as a halogen lamp built therein, the toner image can be fixed by pressing the recording paper against the press roll to heat-fuse the toner. is there.

In such an electrophotographic apparatus, recording papers of various widths are used. For example, there is a case where recording paper having a width narrower than that of the heat roll is used. In that case, if the recording paper is constantly passed through the central portion of the heat roll, the end portion of the heat roll is likely to have an abnormally high temperature as compared with the central portion. Further, when the paper is constantly passed through one end of the heat roll, the central portion and the other end of the heat roll are likely to have an abnormally high temperature as compared with the one end. For the sake of safety, the heat roll should be prevented from having an abnormally high temperature.

Conventionally, temperature sensors are provided near the ends and the center of the heat roll, and only the center or the end of the heat roll has an abnormally high temperature based on the temperatures detected by these sensors. If detected, stop the power supply to the heat source in the heat roll,
The heat roll was prevented from reaching a higher temperature, and the heat roll was allowed to cool naturally.

[0005]

By the way, once the engine of the printer is stopped and the power supply to the heat source is stopped, the temperature of the heat roll decreases, but the engine restarts and the halogen lamp as the heat source is restarted. There was a problem that it took time to generate heat.

In view of the above problems of the conventional heat roll cooling device, the problem of the present invention is that the heat roll partially reaches an abnormally high temperature without stopping the engine to stop the power supply to the heat source. It is to provide a temperature control device for a heat roll that can prevent such a situation.

[0007]

In order to solve the above-mentioned problems, a temperature control device for a heat roll according to a first aspect of the present invention drives a cooling fan based on the temperature measured by a temperature sensor to heat the heat roll. Is designed to be cooled. That is, the temperature control device for a heat roll according to claim 1 is a temperature control device for a heat roll for fixing the toner transferred onto the paper by heat generated from a heat source provided inside the heat roll. A plurality of temperature sensors arranged along the axial direction of the heat roll to measure the temperature of the heat roll, a cooling fan that blows cooling air to the heat roll, and the temperature measured by the plurality of temperature sensors. A control circuit for controlling the amount of cooling air from the cooling fan based on the above.

There may be only one cooling fan or a plurality of cooling fans. Further, when the cooling air from the cooling fan is increased, the control circuit may rotate the cooling fan that has been stopped until then, or increase the rotation speed of the cooling fan that has been rotating until then. May be. When there are a plurality of cooling fans, the amount of cooling air may be controlled for each cooling fan.

According to a second aspect of the present invention, there is provided a heat roll temperature control device in which the plurality of temperature sensors according to the first aspect are arranged at least near the center of the heat roll and near one end thereof, and the cooling fan is provided. Is configured to blow cooling air to both ends of the heat roll, the control circuit, the temperature measured by a temperature sensor arranged near the end of the heat roll near the center of the heat roll. When the temperature is higher than the temperature measured by the temperature sensor arranged, the amount of cooling air from the cooling fan is increased to identify the temperature. According to this structure, even when a paper having a width narrower than that of the heat roll is passed through the center of the heat roll, it is possible to prevent the portion not in contact with the paper from having an abnormally high temperature. .

According to a third aspect of the present invention, there is provided a heat roll temperature control device, wherein the cooling fans are arranged near both ends of the heat roll according to the second aspect.

According to a fourth aspect of the present invention, there is provided a heat roll temperature control device, wherein a plurality of cooling fans according to the first aspect are provided corresponding to the plurality of temperature sensors, respectively, and the surface thereof is controlled by the corresponding temperature sensors. It is specified by blowing cooling air to each area on the surface of the heat roll where the temperature is measured. With this configuration,
It is possible to make the surface temperature of the entire heat roll uniform by cooling that part regardless of the abnormally high temperature, not limited to the end part of the heat roll.

According to a fifth aspect of the present invention, there is provided a heat roll temperature control device according to the fourth aspect, wherein the control circuit according to the fourth aspect is configured to make the temperatures uniform when the temperatures measured by the plurality of temperature sensors are not uniform. It is specified by adjusting the amount of cooling air from each cooling fan.

According to a sixth aspect of the present invention, there is provided a heat roll temperature control device in which a plurality of temperature sensors and cooling fans according to the fourth or fifth aspect are arranged near the center of the heat roll and near both ends thereof. It has been specified.

In the temperature control device for a heat roll according to claim 7, the control part according to claim 5 or 6 increases the amount of cooling air by the cooling fan corresponding to the temperature sensor measuring the temperature higher than the others. That is what was specified.

In order to solve the above-mentioned problems, the heat roll temperature control device according to claim 8 of the present invention controls the cooling air in advance according to the width and position of the paper used so that the heat roll does not heat. It is the one. That is, the temperature control device for the heat roll according to claim 8 is the temperature control device for the heat roll for fixing the toner transferred onto the paper by the heat generated from the heat source provided inside,
A cooling fan for blowing cooling air to the heat roll,
And a control circuit that controls the amount of cooling air from the cooling fan based on the width of the paper and the passing position on the surface of the heat roll.

According to a ninth aspect of the present invention, in the heat roll temperature control device, the control circuit of the eighth aspect allows the paper to pass on the surface of the heat roll when the width of the paper is narrower than a predetermined reference value. This is specified by increasing the amount of cooling air blown to the non-operating area.

According to a tenth aspect of the present invention, there is provided a heat roll temperature control device, wherein the cooling fan according to the ninth aspect is located near the center of the heat roll and near both ends thereof.

According to an eleventh aspect of the present invention, in the heat roll temperature control device, the control circuit of the tenth aspect further controls the amount of cooling air by the cooling fan when the thickness of the paper is a predetermined reference value or more. By increasing the number, it is specified.
If the paper is thick, the degree of temperature distribution also increases. Therefore, by increasing the amount of cooling air, it is possible to prevent the temperature distribution from occurring in such a case.

According to a twelfth aspect of the present invention, in the heat roll temperature control device, when the control circuit according to any one of the first to eleventh aspects increases the amount of the cooling air, the rotation speed of the cooling fan is increased. It has been specified.

In a heat roll temperature control device according to a thirteenth aspect, when the control circuit according to any one of the first to eleventh aspects increases the amount of the cooling air, the cooling fan in a stopped state is rotated. Then, it was specified.

In order to solve the above-mentioned problems, a heat roll temperature control device according to a fourteenth aspect of the present invention is such that the blowing position of the cooling air by the cooling fan is displaced based on the temperature measured by the temperature sensor. . That is,
15. The heat roll temperature control device according to claim 14, wherein the heat roll temperature control device fixes the toner transferred onto the paper by heat generated from a heat source provided inside the heat roll. On the surface of the heat roll, a plurality of temperature sensors arranged along the axial direction of the heat roll to measure the temperature, a cooling fan for blowing cooling air to the heat roll, and cooling air by the cooling fan. Guide means for movably guiding to any part, and controlling the guide means based on the temperature measured by the plurality of temperature sensors to displace the blowing position of the cooling air on the surface of the heat roll. And a control circuit.

The guide means may be one in which the outlet of one duct is movable, or one in which a plurality of ducts are fixedly provided to interrupt the passage of cooling air.
Further, it does not have to have a form of a complete duct whose upper, lower, left and right sides are closed, and may have a form like a straightening plate that changes the flow of cooling air. The control circuit may control the amount of cooling air from the cooling fan in addition to the control of the guide means.

According to a fifteenth aspect of the present invention, there is provided a heat roll temperature control device in which a plurality of temperature sensors according to the fourteenth aspect are arranged near the center of the heat roll and near both ends thereof, and the control circuit includes When the temperatures measured by the plurality of temperature sensors are not uniform, the blowing position of the cooling air on the surface of the heat roll is displaced so that the temperatures are uniform, and the temperature is specified.

According to a sixteenth aspect of the heat roll temperature control device of the present invention, the guide means of the fourteenth or fifteenth aspect is a movable duct for guiding the cooling air from the cooling fan onto the surface of the heat roll. It was done.

According to a seventeenth aspect of the present invention, there is provided a heat roll temperature control apparatus, wherein the control circuit of the fourth aspect is configured so that when the temperature measured by any one of the temperature sensors exceeds a predetermined range. It is specified by adjusting the amount of cooling air from each cooling fan so that it falls within the predetermined range.

According to an eighteenth aspect of the present invention, there is provided a heat roll temperature control device according to the seventeenth aspect, wherein the plurality of temperature sensors and the cooling fan are arranged near the center of the heat roll and near both ends thereof. It was done.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows an example in which the heat roll temperature control device according to the present invention is applied to a laser beam printer. <Schematic Configuration of Laser Beam Printer> A schematic configuration of the laser beam printer 21 will be described with reference to the side configuration diagram of FIG. This laser beam printer is used by connecting it to an external personal computer, etc., and print data (including image data) sent from this personal computer etc.
Is printed on continuous paper (fanfold paper).

First, in FIG. 1, around the photosensitive drum 1, in the order of clockwise, the charging section 2, the reflection mirror 4, and the like.
The developing unit 5 and the transfer unit 7 are provided. And
When the photosensitive drum 1 rotates clockwise in the figure, first, the charging unit 2 charges the surface of the photosensitive drum 1. Next, the reflection mirror 4 reflects the scanning light (modulated light) emitted from the laser scanning unit 3 according to the print data toward the photosensitive drum 1, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. Form. Next, the developing unit 5 attaches toner to the electrostatic latent image to visualize it as a toner image. Next, the transfer unit 7 transfers the toner image onto the fanfold paper 6.

The fanfold paper 6 is a continuous paper drawn from the supply port 21a of the laser printer 21 to the discharge port 21b, and feed holes (not shown) are formed on both side edges at a constant pitch. There is. The tractor 8 is a belt conveyor having a large number of protrusions 8a that fit into the feed holes, and conveys the fanfold paper 6 at the same speed as the rotational peripheral speed of the photosensitive drum 1 by the protrusions 8a.

On the downstream side of the fanfold paper 6 conveyed by the tractor 8, there are provided a heat roll 9 and a press roll 11 which sandwich the fanfold paper 6 from both sides and press it into contact therewith. The heat roll 9 has a halogen lamp 10 for heat generation therein, and the fan fold paper 6 can be driven by a motor (not shown).
It is rotationally driven at the same rotation peripheral speed as the transport speed of. on the other hand,
The press roll 11 is in pressure contact with the heat roll 9 at a constant pressure, and is rotationally driven as the heat roll 9 rotates. Therefore, the portion of the fanfold paper 6 on which the toner image is transferred is the heat roll 9 and the press roll 1.
When the toner image passes through 1 and 1, the toner is crushed by heat and pressure and fused on the fanfold paper 6, and the toner image is fixed.

On the surface of the heat roll 9, three thermistors 14 (only one is shown in FIG. 1) for measuring the surface temperature of the heat roll 9 are provided.
In addition, on the same side as the heat roll 9 with respect to the fanfold paper 6, at a position closer to the tractor 8 than the heat roll 9, there are three (only one shown in FIG. 1) for blowing cooling air to the heat roll 9. ) Cooling fan 1
2 are arranged. On the other hand, on the same side as the press roll 11 with respect to the fanfold paper 6, even at a position closer to the tractor 8 than the press roll 11, there are three (only one is shown in FIG. 1) for blowing cooling air to the press roll 11. ) Cooling fan 13 is arranged. The positional relationship between the thermistor 14 and the cooling fans 12 and 13 with respect to the rolls 9 and 11 is shown in the perspective view of FIG.

As shown in FIG. 2, the surface temperature near the left end of the heat roll 9 is measured so as to face the surface near the left end of the heat roll 9 when viewed from the tractor 8 side. The first thermistor 14a is arranged. Also, facing the surface near the right end of the heat roll 9,
A third thermistor 14c is arranged to measure the surface temperature near the right end of the heat roll 9. A second thermistor 14b for measuring the surface temperature near the center of the heat roll 9 is arranged so as to face the surface near the center of the heat roll 9.

Further, corresponding to the first thermistor 14a,
A first heat roll cooling fan 12a for blowing cooling air is arranged near the left end of the heat roll 9, and corresponding to the third thermistor 14c, a cooling air is blown near the right end of the heat roll 9. A third heat roll cooling fan 12c is arranged, and a second heat roll cooling fan 12b for blowing cooling air is arranged near the center of the heat roll 9 corresponding to the second thermistor 14b.

Further, a first press roll cooling fan 13a for blowing cooling air near the left end of the press roll 11 is arranged at a position symmetrical to the first heat roll cooling fan 12a with the fanfold paper 6 interposed therebetween. A third press roll cooling fan 13c for blowing cooling air near the right end of the press roll 11 is arranged at a position symmetrical to the third heat roll cooling fan 12c, and a second heat roll cooling fan 12b is provided. A second press roll cooling fan 13b for blowing cooling air is arranged near the center of the press roll 11 at symmetrical positions.
In the present embodiment, the first thermistor 14a and the third thermistor 14c are separated from each other by 8 inches or more. In addition, the first thermistor 14a and the second thermistor 1
The distance between the second thermistor 14b and the third thermistor 14c is 4 inches or more.

The thermistors 14a-c and the cooling fans 12a-c, 13a-c are connected to the engine control unit 15, respectively. The engine control unit 15 has
In addition, the controller unit 16 and the halogen lamp 10 are connected. In addition to the controller unit 16, the operation unit 17 and the external personal computer 18 described above are connected.

The external personal computer or the like 18 sends to the controller section 16 the print data, the designation information of the width and thickness of the paper to be printed, and the designation information of the printing position. The designation information of the print position is the reflection mirror 4
From the side, whether the center of the electrostatic latent image formed by the laser scanning unit 3 and the reflection mirror 4 is aligned with the center of the photosensitive drum 1 (center registration) or the left end of the electrostatic latent image is aligned with the left end of the photosensitive drum 1 ( The left side resist) is information for specifying whether the right end of the electrostatic latent image is aligned with the right end of the photosensitive drum 1 (right side resist).

The paper width and thickness designation information and the print position designation information can be directly input to the controller unit 16 by the operation unit 17. The controller unit 16 is a processing device that controls the entire laser beam printer 21, and modulates the laser beam emitted from the laser beam scanning unit 3 based on print data received from an external personal computer 18 or the like, and controls the paper. The laser beam scanning unit 3 is caused to perform scanning based on the width designation information and the print position designation information.
The controller unit 16 also drives the photosensitive drum 1, the tractor 8 and the heat roll 9 to convey the fanfold paper 6, and also activates the charging unit 2, the developing unit 5 and the transfer unit 7 to perform fanfold paper. A toner image is formed on the surface 6 by laser beam scanning. Controller unit 16
When performing printing based on one print data, the engine control unit 15 is requested to specify the paper width and thickness designation information,
In addition, the print position designation information is notified and the print start is notified.

The engine control unit 15 as a control circuit is
It is a circuit that drives and controls a printer engine (a motor (not shown) that rotates the heat roller 9, a halogen lamp 10, etc.) under the control of the controller unit 16. The engine control unit 15 lights the halogen lamp 10 to heat the heat roll 9 when the laser beam printer 21 is in the operating state.

The engine control unit 15 is the controller unit 1.
Specification information of width and thickness of paper to be printed from 6, and
When the notification of the designation information of the printing position is received, the information is analyzed and the portion on the surface of the heat roll 9 where the fanfold paper 6 passes and the portion where the fanfold paper 6 does not pass are specified. Then, the thermistors 14a to 14c located near the portion through which the fanfold paper 6 passes are set for temperature control, and based on the surface temperature of the heat roll 9 measured by the thermistor 14 set for this temperature control. Then, the halogen lamp 10 is made to blink. In this way, the engine control unit 15 controls so that the temperature of the surface of the heat roll 9 at this portion maintains a predetermined constant value suitable for fixing the toner.

On the other hand, the engine control unit 15 includes the heat roll cooling fan 12 and the press roll cooling fan 1 which are located in the vicinity of the portion where the fanfold paper 6 does not pass.
By rotating 3 the cooling air is blown to the relevant part, and this part is prevented from having an abnormally high temperature as compared with the part through which the fanfold paper 6 passes. When the thickness of the paper included in the designation information is thicker than a predetermined reference value, the engine control unit 15 increases the rotation speeds of the heat roll cooling fan 12 and the press roll cooling fan 13 to generate the cooling air. Increase the amount.

During printing, the engine control unit 15
Recognizes the temperature distribution on the surface of the heat roll 9 by comparing the surface temperature measured by the thermistor 14 set for temperature control with the surface temperature measured by the other thermistors 14. Then, when an abnormally high temperature portion is detected as compared with the surface temperature of the portion through which the fanfold paper 6 passes, the heat roll cooling fan 1 located near the high temperature portion is detected.
2 and the rotation speed of the press roll cooling fan 13 are increased to increase the amount of cooling air to cool the high temperature portion. on the other hand,
When an abnormally low temperature portion is detected in comparison with the surface temperature of the portion through which the fanfold paper 6 passes, the rotation of the heat roll cooling fan 12 and the press roll cooling fan 13 located near this low temperature portion is rotated. The number is decreased to reduce the amount of cooling air, and the surface temperature of this low temperature part is increased.
By the above control, the engine control unit 15 can keep the surface temperature of the heat roll 9 uniform.

The signal line for transmitting the control signal from the engine control unit 15 to each of the cooling fans 12 and 13 is 2 in the middle.
It branches into a book and is connected to a heat roll cooling fan 12 and a press roll cooling fan 13, which are located symmetrically with respect to the fanfold paper 6, respectively. Therefore, the same control signal is transmitted to the pair of heat roll cooling fan 12 and press roll cooling fan 13 which are located at these symmetrical positions, so that they can increase and decrease their rotation speeds in perfect synchronization. become. In the following, the set of heat roll cooling fans 12 and the press roll cooling fans 13 located symmetrically are collectively referred to as the cooling fans 12, 13 (first cooling fans 12a, 13a, second cooling fan 12b,
13b, the third cooling fan 12c, 13c). <Engine Control Processing> Next, the control processing executed by the engine control unit 15 will be described with reference to the flowcharts of FIGS.

This control process is triggered by the reception of paper information (paper width and thickness designation information, and print position designation information) from the controller section 16. In S001, which is the first time after the start, the engine control unit 15 waits until the input of the information on this paper is completed. When the paper information has been input, the engine control unit 15
The process proceeds to S002.

In this S002, the engine control unit 15
Analyzes the paper information (print position designation information) input in S001 to identify the paper position (print position).
Specifically, when the designation information of the print position indicates the left side resist, the engine control unit 15 causes the left end of the paper (print position) to be seen from the supply port 21a side when the photosensitive drum 1 and the heat roll 9 are used. When it is determined that the left end of the line is matched, the process proceeds to S003. When the print position designation information indicates the center registration, the engine control unit 1
5 determines that the center of the paper (printing position) is aligned with the center of the photosensitive drum 1 and the heat roll 9, and the process is S00.
Proceed to 9. When the designation information of the print position indicates the right side resist, the engine control unit 15 determines that the right end of the paper (print position) is the right end of the photosensitive drum 1 and the heat roll 9 when viewed from the supply port 21a side. If it is determined that they match, the process proceeds to S014.

In S003, the engine controller 15 sets the first thermistor 14a as a temperature control thermistor. In next step S004, the engine control unit 15 analyzes the paper information (paper width designation information) and checks whether the paper width is 8 inches or more. And the paper width is 8
If it is at least inches, it is considered that the temperature distribution does not occur on the surfaces of the heat roll 9 and the press roll 11 because there is almost no portion through which the fanfold paper 6 does not pass, and S005
At, all the cooling fans 12 and 13 are stopped. On the other hand, if the paper width is less than 8 inches, the engine control unit 15 checks in S006 whether the paper width is 4 inches or more. Then, if the paper width is 4 inches or more, it is considered that the vicinity of the right ends of the heat roll 9 and the press roll 11 is likely to become high temperature, and in S007, the third cooling fans 12c and 13c are rotated at the initial speed NR. On the other hand, if the paper width is less than 4 inches, it is considered that the temperature near the center and the vicinity of the right end of the heat roll 9 and the press roll 11 are likely to be high, and in S008, the second cooling fans 12b and 13b and the third cooling fan are heated. 12c and 13c are rotated at the initial rotation speed NR [rpm]. In any case, the engine control unit 15 then advances the process to S019.

On the other hand, in S009, the engine control unit 15
Sets the second thermistor 14b as a temperature control thermistor. In the next S010, the engine control unit 15
Analyzes the paper information (paper width designation information) and checks whether the paper width is 8 inches or more. And
If the paper width is 8 inches or more, it is considered that there is no temperature distribution on the surfaces of the heat roll 9 and the press roll 11 because there is almost no part where the fanfold paper 6 does not pass,
In S011, all the cooling fans 12 and 13 are stopped. On the other hand, if the paper width is less than 8 inches, the engine control unit 15 considers that the vicinity of both ends of the heat roll 9 and the press roll 11 is likely to become high temperature, and in S012, the first cooling fans 12a, 13a and the first cooling fans 12a, 13a. 3 The cooling fans 12c and 13c are rotated at the initial rotation speed NR [rpm]. In any case, the engine control unit 15
Next advances the process to S019.

On the other hand, in S013, the engine control unit 15
Sets the third thermistor 14c as a temperature control thermistor. In the next S014, the engine control unit 15
Analyzes the paper information (paper width designation information) and checks whether the paper width is 8 inches or more. And
If the paper width is 8 inches or more, it is considered that there is no temperature distribution on the surfaces of the heat roll 9 and the press roll 11 because there is almost no part where the fanfold paper 6 does not pass,
In S015, all the cooling fans 12 and 13 are stopped. On the other hand, if the paper width is less than 8 inches, the engine control unit 15 checks in S016 whether the paper width is 4 inches or more. If the paper width is 4 inches or more, it is considered that the vicinity of the left end of the heat roll 9 and the press roll 11 is likely to become high temperature, and S001
7, the first cooling fans 12a and 13a are rotated at the initial rotation speed NR [rpm]. On the other hand, if the paper width is less than 4 inches, it is considered that the temperature near the center and near the left end of the heat roll 9 and the press roll 11 is likely to become high, and in S018, the first cooling fans 12a and 13a.
Also, the second cooling fans 12b and 13b are rotated at the initial speed NR. In any case, the engine control unit 1
Then, the process proceeds to S019.

In step S019, the engine control unit 15 analyzes the paper information (paper thickness designation information) and determines that the paper thickness is 0.
Identify whether it is 15 mm or less. If the paper thickness is 0.15 mm or less, the process is directly performed in S021.
Proceed to On the other hand, when the paper thickness is thicker than 0.15 mm, the engine control unit 15 considers that the temperature distribution becomes larger when the temperature distribution occurs on the surfaces of the heat roll 9 and the press roll 11. , S020
In this case, the number of rotations of the cooling fans 12 and 13 currently rotating at 1.5 times the initial number of rotations (NR [rpm]) (1.5N
R [rpm]), and then the process proceeds to S021.

In S021, the engine control unit 15 waits for the notification of the start of printing from the controller unit 16. Then, when the start of printing is notified, the engine control unit 15 advances the processing to S022.

In S022, the engine control unit 15 causes the S
The temperature measured by the thermistor 14 set for temperature control in 003, S009 or S013 (hereinafter, "T
R ”), so that the surface temperature of the portion of the surface of the heat roll 9 measured by the temperature control thermistor 14 becomes constant.
ON / OFF adjustment. That is, the engine control unit 15
Controls the halogen lamp 10 so that the halogen lamp 10 is turned on only when the temperature measured by the temperature control thermistor 14 is equal to or lower than a predetermined reference value.

In the next S023, the engine control unit 15
Is the temperature measured by the first thermistor 14a (T
The temperature (TR) measured by the temperature control thermistor 14 is subtracted from 1) and the temperature difference between them is checked. Then, when the difference between T1 and TR is within +/− 10 degrees (including the case where the first thermistor 14a is set as the temperature control thermistor), the engine control unit 15 directly performs the process in S028. Proceed to.

On the other hand, if the temperature (T1) measured by the first thermistor 14a is higher than the temperature (TR) measured by the temperature control thermistor 14 by 10 degrees or more, the engine control section 15 determines in S024 It is checked whether or not the current rotational speeds of the 1 cooling fans 12a and 13a are more than twice the initial rotational speed (NR [rpm]) (2NR [rpm]). And the current speed is 2NR
If it is equal to or higher than [rpm], the engine control unit 15
The process proceeds directly to S028. On the other hand, when the current rotational speed is less than 2NR [rpm], the engine control unit 15 determines in S025 that the first cooling fan 1
The rotation speed of 2a and 13a is increased by 50% from the current value. At this time, if the first cooling fans 12a and 13a were originally stopped, the initial rotation speed (NR [rpm])
50% (0.5NR [rpm]) of the first cooling fan 12
a and 13a are rotated. After that, the engine control unit 15
Advances the process to S028.

On the other hand, when the temperature (T1) measured by the first thermistor 14a is lower than the temperature (TR) measured by the temperature control thermistor 14 by 10 degrees or more, the engine control section 15 determines in S026 1 Check whether the cooling fans 12a and 13a are stopped. Then, when the first cooling fans 12a and 13a are stopped, the engine control unit 15 advances the process directly to S028. On the other hand, when the first cooling fans 12a and 13a are not stopped, the engine control unit 15 determines in S027 the first cooling fan 12
The rotation speeds of a and 13a are lowered by 50% from the current value. After that, the engine control unit 15 advances the processing to S028.

In S028, the engine controller 15 subtracts the temperature (TR) measured by the temperature control thermistor 14 from the temperature (T2) measured by the second thermistor 14b and checks the temperature difference. When the difference between T2 and TR is within ± 10 degrees (including the case where the second thermistor 14b is set as the temperature control thermistor), the engine control unit 1
In step 5, the process directly proceeds to S033.

On the other hand, if the temperature (T2) measured by the second thermistor 14b is higher than the temperature (TR) measured by the temperature control thermistor 14 by 10 degrees or more, the engine control unit 15 determines in S029 that 2 It is checked whether the current rotation speed of the cooling fans 12b and 13b is more than twice the initial rotation speed (NR [rpm]) (2NR [rpm]). And the current speed is 2NR
If it is equal to or higher than [rpm], the engine control unit 15
The process proceeds directly to S033. On the other hand, when the current rotation speed is less than 2NR [rpm], the engine control unit 15 determines in S030 the second cooling fan 1
The rotation speed of 2b and 13b is increased by 50% from the current value. At this time, if the second cooling fans 12b and 13b were originally stopped, the initial rotation speed (NR [rpm])
Second cooling fan 12 at 50% (0.5 NR [rpm])
Rotate b and 13b. After that, the engine control unit 15
Advances the process to S033.

On the other hand, when the temperature (T2) measured by the second thermistor 14b is lower than the temperature (TR) measured by the temperature control thermistor 14 by 10 degrees or more, the engine control unit 15 determines in S031 2 Check whether the cooling fans 12b and 13b are stopped. Then, when the second cooling fans 12b and 13b are stopped, the engine control unit 15 advances the process directly to S033. On the other hand, when the second cooling fans 12b and 13b are not stopped, the engine control unit 15 determines in S032 the second cooling fan 12b.
The rotation speeds of b and 13b are reduced by 50% from the current value. After that, the engine control unit 15 advances the processing to S033.

In S033, the engine controller 15 subtracts the temperature (TR) measured by the temperature control thermistor 14 from the temperature (T3) measured by the third thermistor 14c and checks the temperature difference. When the difference between T3 and TR is within ± 10 degrees (including the case where the third thermistor 14c is set as the temperature control thermistor), the engine control unit 1
In No. 5, the process directly proceeds to S038.

On the other hand, if the temperature (T3) measured by the third thermistor 14c is higher than the temperature (TR) measured by the temperature control thermistor 14 by 10 degrees or more, the engine control unit 15 determines in S034 It is checked whether the current rotation speed of the three cooling fans 12c and 13c is more than twice the initial rotation speed (NR [rpm]) (2NR [rpm]). And the current speed is 2NR
If it is equal to or higher than [rpm], the engine control unit 15
The process directly proceeds to S038. On the other hand, when the current rotation speed is less than 2NR [rpm], the engine control unit 15 determines in S035 that the third cooling fan 1
The rotation speeds of 2c and 13c are increased by 50% from the current value. At this time, if the third cooling fans 12c and 13c were originally stopped, the initial rotation speed (NR [rpm])
50% (0.5NR [rpm]) of the third cooling fan 12
Rotate c and 13c. After that, the engine control unit 15
Advances the process to S038. On the other hand, the third thermistor 1
When the temperature (T3) measured by 4c is lower than the temperature (TR) measured by the temperature control thermistor 14 by 10 degrees or more, the engine control unit 15 stops the third cooling fans 12c and 13c in S036. Check if you are doing. Then, the third cooling fan 12
When c and 13c are stopped, the engine control unit 1
In No. 5, the process directly proceeds to S038. On the other hand, when the third cooling fans 12c and 13c are not stopped, the engine control unit 15 reduces the rotation speed of the third cooling fans 12c and 13c by 50% from the current value in S037. . After that, the engine control unit 15 advances the processing to S038.

In S038, the engine control unit 15 causes the S
At 021, it is checked whether printing based on the print data notified of the start of printing is completed. Then, when the printing based on the print data is not completed yet, the engine control unit 15 returns the process to S022. On the other hand, when the printing based on the print data is completed, the engine control unit 15 terminates this control process, and the information of the next paper (paper width and thickness designation information, and printing). It waits for notification of (position designation information) from the controller unit 16. <Operation of the Embodiment> According to the present embodiment configured as described above, the fanfold paper 6 passes based on the paper width and the print position designated by the operator through the external personal computer 18 or the operation unit 17. Therefore, a portion on the surface of the heat roll 9 that is likely to have an abnormally high temperature is specified in advance. Then, in order to prevent the occurrence of such an abnormally high temperature, the cooling air is blown from any of the cooling fans 12 and 13 to such a portion from the initial stage of printing. Further, when the thickness of the paper designated by the operator through the external personal computer 18 or the operation unit 17 is thicker than 0.15 mm, the abnormal high temperature is expected to be larger, so that the amount of cooling air is increased. To be done.

When a temperature distribution exceeding the prediction occurs as a result of actual printing, a fanfold is applied to correct the temperature distribution and make the temperature on the surface of the heat roll 9 uniform. By increasing the amount of cooling air blown to a portion having a temperature higher than the temperature of the portion through which the paper 6 passes by 10 degrees or more (increasing the number of rotations of the cooling fans 12 and 13 corresponding to the thermistor 14 measuring a temperature higher than 10 degrees), The cooling air blown to a portion which is lower than the temperature of the portion through which the fanfold paper 6 passes by 10 degrees or more is reduced (the number of rotations of the cooling fans 12 and 13 corresponding to the thermistor 14 measuring the temperature lower than 10 degrees is reduced. ). Thereby, even if the temperature distribution occurs on the surfaces of the heat roll 9 and the press roll 11 after the start of printing, this can be immediately corrected.

[0061]

Embodiment 2 The second embodiment of the present invention is the same as the first embodiment described above.
Compared with the embodiment of the above, the control of the cooling fans 12 and 13 according to the difference between the temperature (TR) measured by the temperature control thermistor 4 and the temperatures (T1 to T3) measured by other thermistors 4 ( Without performing S023 to S037),
Temperature measured by each thermistor 4 (T1 to T3)
Is compared with preset upper limit value (TH) and lower limit value (TL), respectively, and based on the comparison result, each temperature (T1 to
T3) is controlled so as to be between the upper limit value and the lower limit value (the temperature controllable range by turning ON / OFF the halogen lamp 10).

Since the hardware configuration of the second embodiment is exactly the same as that of the first embodiment, its explanation is omitted. <Engine Control Processing> The control processing executed by the engine control unit 15 of the second embodiment will be described with reference to the flowcharts of FIGS. 6 to 8.

S101 to S122 in this control process
The process of S001 to S0 in the above-described first embodiment.
Since it is exactly the same as the processing of 22, the description thereof will be omitted. S
In 123, the engine control unit 15 uses the first thermistor 1
Check the temperature (T1) measured by 4a.
If T1 is between the preset lower limit value (TL) and upper limit value (TH), the engine control unit 15
Advances the processing directly to S128.

On the other hand, when the temperature (T1) measured by the first thermistor 14a is equal to or higher than the preset upper limit value (TH), the engine control section 15 determines in S124 that the first cooling fans 12a and 13a are in operation. The current rotation speed of is twice the initial rotation speed (NR [rpm]) (2NR [rpm])
Check if this is the case. Then, when the current rotation speed is 2NR [rpm] or more, the engine control unit 15 advances the process directly to S128. On the other hand, if the current rotation speed is less than 2NR [rpm], the engine control unit 15 determines in S125 that the first
The number of rotations of the cooling fans 12a and 13a is set to 5 from the current value.
Increase by 0%. At this time, the first cooling fan 12
When a and 13a are originally stopped, the first speed is 50% (0.5NR [rpm]) of the initial rotation speed (NR [rpm]).
The cooling fans 12a and 13a are rotated. After that, the engine control unit 15 advances the processing to S128.

On the other hand, when the temperature (T1) measured by the first thermistor 14a is equal to or lower than the preset lower limit value (TL), the engine control section 15 causes the first cooling fans 12a and 13a in S126. Check if is stopped. Then, the first cooling fan 12
When a and 13a are stopped, the engine control unit 1
In No. 5, the process proceeds directly to S128. On the other hand, when the first cooling fans 12a and 13a are not stopped, the engine control unit 15 reduces the rotation speed of the first cooling fans 12a and 13a by 50% from the current value in S127. . After that, the engine control unit 15 advances the processing to S128.

In S128, the engine controller 15 checks the temperature (T2) measured by the second thermistor 14b. Then, when T1 is between the preset lower limit value (TL) and upper limit value (TH), the engine control unit 15 advances the process directly to S133.

On the other hand, when the temperature (T2) measured by the second thermistor 14b is equal to or higher than the preset upper limit value (TH), the engine control section 15 determines in S129 that the second cooling fans 12b and 13b are in operation. The current rotation speed of is twice the initial rotation speed (NR [rpm]) (2NR [rpm])
Check if this is the case. Then, when the current rotation speed is 2NR [rpm] or more, the engine control unit 15 advances the process directly to S133. On the other hand, when the current rotation speed is less than 2NR [rpm], the engine control unit 15 determines in S130 that the second
The number of rotations of the cooling fans 12b and 13b is set to 5 than the current value.
Increase by 0%. At this time, the second cooling fan 12
When b and 13b are originally stopped, the second speed is set to 50% (0.5NR [rpm]) of the initial rotation speed (NR [rpm]).
The cooling fans 12b and 13b are rotated. After that, the engine control unit 15 advances the processing to S133.

On the other hand, when the temperature (T2) measured by the second thermistor 14b is equal to or lower than the preset lower limit value (TL), the engine control section 15 causes the second cooling fans 12b and 13b to proceed in S131. Check if is stopped. Then, the second cooling fan 12
If b and 13b are stopped, the engine control unit 1
In No. 5, the process directly proceeds to S133. On the other hand, when the second cooling fans 12b and 13b are not stopped, the engine control unit 15 reduces the rotation speed of the second cooling fans 12b and 13b by 50% from the current value in S132. . After that, the engine control unit 15 advances the processing to S133.

In S133, the engine controller 15 checks the temperature (T3) measured by the third thermistor 14c. Then, when T3 is between the preset lower limit value (TL) and upper limit value (TH), the engine control unit 15 advances the process directly to S138.

On the other hand, when the temperature (T3) measured by the third thermistor 14c is equal to or higher than the preset upper limit value (TH), the engine control section 15 causes the third cooling fans 12c and 13c in S134. The current rotation speed of is twice the initial rotation speed (NR [rpm]) (2NR [rpm])
Check if this is the case. Then, when the current rotation speed is 2NR [rpm] or more, the engine control unit 15 advances the process directly to S138. On the other hand, when the current rotation speed is less than 2NR [rpm], the engine control unit 15 determines in step S135 that the third
The number of rotations of the cooling fans 12c and 13c is set to 5 than the current value.
Increase by 0%. At this time, the third cooling fan 12
When c and 13c are originally stopped, the third rotation is performed at 50% (0.5NR [rpm]) of the initial rotation speed (NR [rpm]).
The cooling fans 12c and 13c are rotated. After that, the engine control unit 15 advances the processing to S138.

On the other hand, when the temperature (T3) measured by the third thermistor 14c is equal to or lower than the preset lower limit value (TL), the engine control section 15 determines in S136 that the third cooling fans 12c and 13c. Check if is stopped. Then, the third cooling fan 12
When c and 13c are stopped, the engine control unit 1
In No. 5, the process directly proceeds to S138. On the other hand, when the third cooling fans 12c and 13c are not stopped, the engine control unit 15 reduces the rotation speed of the third cooling fans 12c and 13c by 50% from the current value in S137. . After that, the engine control unit 15 advances the processing to S138.

In S138, the engine control unit 15 causes the S
At 121, it is checked whether printing based on the print data notified of the start of printing is completed. Then, when the printing based on the print data is not completed yet, the engine control unit 15 returns the process to S122. On the other hand, when the printing based on the print data is completed, the engine control unit 15 terminates this control process, and the information of the next paper (paper width and thickness designation information, and printing). It waits for notification of (position designation information) from the controller unit 16. <Operation according to the embodiment> The second embodiment configured as described above
According to the embodiment, as a result of performing actual printing, a low temperature portion exceeding a predetermined lower limit value (TL) and an upper limit value (TH) (a temperature controllable range by turning ON / OFF the halogen lamp 10). Alternatively, when a high temperature portion is generated, the cooling air blown to the high temperature portion having the upper limit value (TH) or more so that the temperature distribution is corrected and the surface temperature of the heat roll 9 is entirely within the temperature controllable range. Is increased and the cooling air blown to the low temperature portion below the lower limit value (TL) is decreased. Thereby, even if the temperature distribution occurs on the surfaces of the heat roll 9 and the press roll 11 after the start of printing, this can be immediately corrected.

[0073]

Third Embodiment FIG. 9 is a plan view of each component between the photosensitive drum 1 and the heat roll 9 in the laser beam printer to which the heat roll temperature control device according to the present invention is applied. Note that, in FIG. 9, only the configuration above the fanfold paper 6 (on the heat roll 9 side) is illustrated, and the same reference numerals are given to the same components as in the first embodiment.

In the third embodiment, as shown in FIG. 9, the cooling fan 22 for the heat roll 9 is located at a position slightly separated from the surface of the central portion of the heat roll 9.
Only one is fixed. The fixed partition plate 2 for preventing the diffusion of the cooling air blown out from the cooling fan 22 between the both side edges of the cooling fan 22 and both ends of the heat roll 9.
3a and 23b are fixed. Also, heat roll 9
Rotating shafts 24a and 25a oriented in a direction orthogonal to the paper surface of FIG. 9 are provided at positions where the two fixed partition plates 23a and 23b are equally divided into three parts in the vicinity of. The rotary partition plates 24, 25a are respectively attached to the rotary shafts 24a, 25a.
One end of 25 is rotatably supported, and the movable partition plates 24 and 25 are rotatable around the rotary shafts 24a and 25a. These moving partition plates 24, 2
At the other end of 5, cam pins 24b, 25b oriented in a direction orthogonal to the paper surface of FIG. 9 are fixed. In addition, each of these fixed partition plates 23a and 23b and the movable partition plates 24 and 25.
The shape of the heat roll 9 is in the direction orthogonal to the paper surface of FIG.
Has a rectangular plate shape having a width substantially equal to the diameter of.

On the other hand, on the fanfold paper 6 side of the cooling fan 22, with a long distance from the cooling fan 22 and its major axis oriented in the conveying direction of the fanfold paper 6, a rectangular plate-shaped partition plate. An adjusting tool 26 is arranged. A ball nut (not shown) that is screwed into a ball screw 28 that is installed in the direction in which the fanfold paper 6 is conveyed is fixed to the back side surface of the partition plate adjusting tool 26. Therefore, by rotating the ball screw 28 in either forward or reverse directions by the motor 27, the partition plate adjusting tool 26 can be moved back and forth in the conveying direction of the fanfold paper 6.

FIG. 10 is a plan view of the partition plate adjusting tool 26.
Shown in As is apparent from FIG. 10, the cam pin 24b of the moving partition plate 24 is provided on the surface of the partition plate adjusting tool 26.
A cam groove 26a into which the cam pin 26b fits and a cam groove 26b into which the cam pin 25b of the moving partition plate 25 fits are formed.
Therefore, by moving the partition plate adjuster 26 back and forth, both moving partition plates 24, 25 can be rotationally moved to the rotational position uniquely determined by the shapes of the cam grooves 26a, 26b. As a result, both fixed partition plates 23a, 23
It is possible to change the shape of the duct formed by b and the moving partition plates 24 and 25, and blow the cooling air to an arbitrary portion on the surface of the heat roll 9 (corresponding to the guide means).

That is, it is assumed that a reference line FC passing through the center of the cooling fan 22 and oriented in the width direction of the fanfold paper 6 is defined as shown in FIG. Then, when the partition plate adjusting tool 26 moves so that the relative positional relationship of the reference line FC to the partition plate adjusting tool 26 becomes the state shown in P4 of FIG. 10, the fixed partition plate 23a and the moving partition plate 24 are moved. And the space between the movable partition plates 24 and 25 are closed, so that the cooling air is blown only to the vicinity of the left end of the heat roll 9 as viewed from the photosensitive drum 1 side.

The reference line F for the partition plate adjusting tool 26
When the partition plate adjusting tool 26 is moved so that the relative positional relationship of C becomes the state shown in P2 of FIG. 10, only the fixed partition plate 23a and the movable partition plate 24 are closed. When viewed from the drum 1 side, the cooling air is blown only to the vicinity of the left end portion and the center of the heat roll 9.

The reference line F for the partition plate adjusting tool 26
When the partition plate adjusting tool 26 is moved so that the relative positional relationship of C becomes the state shown in P0 of FIG. 10, the space between the fixed partition plates 23a and 23b and the movable partition plates 24 and 25 is increased. Since it can be opened evenly, cooling air can be blown to the entire heat roll 9.

The reference line F for the partition plate adjusting tool 26
When the partition plate adjusting tool 26 is moved so that the relative positional relationship of C becomes the state shown in P1 of FIG. 10, only both moving partition plates 24 and 25 are closed, so that both ends of the heat roll 9 are closed. The cooling air is blown only near the part.

Further, the reference line F for the partition plate adjusting tool 26
When the partition plate adjuster 26 is moved so that the relative positional relationship of C becomes the state shown in P3 of FIG. 10, the fixed partition plates 23a and 23b and the movable partition plates 24 and 25 are separated from each other. Since it can be opened evenly, cooling air can be blown to the entire heat roll 9.

Further, the reference line F for the partition plate adjusting tool 26
When the partition plate adjuster 26 is moved so that the relative positional relationship of C becomes the state shown in P5 of FIG. 10, only the space between the fixed partition plate 23b and the movable partition plate 25 is closed. When viewed from the drum 1 side, the cooling air is blown only to the vicinity of the right end portion and the vicinity of the center of the heat roll 9.

The reference line F for the partition plate adjusting tool 26
When the partition plate adjusting tool 26 is moved so that the relative positional relationship of C becomes the state shown in P6 of FIG. 10, between the fixed partition plate 23b and the moving partition plate 25, and the moving partition plate 2
Since 5 and 24 are closed, the cooling air is blown only to the vicinity of the right end portion of the heat roll 9 when viewed from the photosensitive drum 1 side.

The engine control unit 15 in this embodiment
Controls the rotation direction and rotation amount of the motor 27 based on the surface temperature of the heat roll 9 measured by the thermistors 14a to 14c, and controls the position of the partition plate adjusting tool 26.

That is, as in the case of the first embodiment, first, the input paper information is analyzed to determine whether it is the left side resist, the center resist, or the right side resist. To do.

If it is the left side resist, the first thermistor 14a is set for temperature control,
Only when the paper width is less than 8 inches, the cooling fan 22 is rotated and the partition plate adjusting tool 26 is moved back and forth. That is, when the paper width is 4 inches or more, the reference line FC is moved to the position P6 in FIG. 10 with respect to the partition plate adjusting tool 26. As a result, when viewed from the photosensitive drum 1 side, the cooling air is blown only to the vicinity of the right end portion of the heat roll 9. If the paper width is less than 4 inches,
The reference line FC for this partition plate adjusting tool 26 is P in FIG.
Move to position 5. As a result, when viewed from the photosensitive drum 1 side, the cooling air is blown only to the vicinity of the central portion and the vicinity of the right end portion of the heat roll 9.

If it is a center resist,
The second thermistor 14b is set for temperature control, and only when the paper width is less than 8 inches, the cooling fan 22 is rotated and the partition plate adjusting tool 26 is moved back and forth to refer to the partition plate adjusting tool 26. The line FC is moved to the position P1 in FIG. As a result, the heat roll 9
The cooling air is blown only to the vicinity of both ends of the.

When the resist is the right side resist,
The third thermistor 14c is set for temperature control, and only when the paper width is less than 8 inches, the cooling fan 22 is rotated and the partition plate adjusting tool 26 is moved back and forth. That is,
When the paper width is 4 inches or more, the reference line FC is moved to the position P4 in FIG. 10 with respect to the partition plate adjusting tool 26. As a result, when viewed from the photosensitive drum 1 side,
Cooling air is blown only to the vicinity of the left end of the heat roll 9. When the paper width is less than 4 inches, the reference line FC is moved to the position P2 in FIG. 10 with respect to the partition plate adjusting tool 26. Thereby, the photosensitive drum 1
When viewed from the side, the cooling air is blown only to the vicinity of the central portion and the vicinity of the left end portion of the heat roll 9.

When the paper information specifies a paper thicker than 0.15 mm, the engine control unit 15 sets the rotation speed of the cooling fan 22 to the initial rotation speed (NR [rp
m]) 1.5 times (1.5 NR [rpm])
Increase the cooling air.

After the start of printing, the engine control unit 15 makes the surface temperature of the region measured by the temperature control thermistor 14 a constant value based on the temperature measured by the temperature control thermistor 14. Thus, the halogen lamp 10 is ON / OFF controlled.

Thereafter, the engine controller 15 detects whether or not a temperature distribution is generated on the surface of the heat roll 9 based on the temperatures measured by the thermistors 14a to 14c.

Then, when the first thermistor 14a is set for temperature control, the temperature measured by the other two thermistors 14b and 14c is higher than the temperature measured by the first thermistor 14a by 10 degrees or more. If it becomes, move the partition plate adjustment tool 26,
The reference line FC for this partition plate adjusting tool 26 is P in FIG.
Move to position 5. Further, only the temperature measured by the third thermistor 14c is the first thermistor 1
When the temperature becomes higher than the temperature measured by 4a by 10 degrees or more, the reference line FC is moved to the position P6 of FIG. 10 with respect to the partition plate adjusting tool 26. In these cases, if the cooling fan 22 has been stopped until then, the cooling fan 22 is set to the initial rotation speed (NR [rp
m]) at 50% (0.5 NR [rpm]).

In addition, when the second thermistor 14b is set for temperature control, the temperature measured by the other two thermistors 14a and 14c is higher than the temperature measured by the second thermistor 14b by 10 degrees or more. When it becomes, the partition plate adjusting tool 26 is moved so that the reference line FC is P1 in FIG. 10 with respect to the partition plate adjusting tool 26.
Move to the position. Also, the first thermistor 1
Only the temperature measured by 4a is the second thermistor 14
When the temperature becomes higher than the temperature measured by b by 10 degrees or more, the reference line FC with respect to the partition plate adjusting tool 26 is shown in FIG.
Move to the position of P4 of 0. Further, when only the temperature measured by the third thermistor 14c becomes higher than the temperature measured by the second thermistor 14b by 10 degrees or more, the reference line F with respect to the partition plate adjusting tool 26 is used.
Let C move to the position of P6 in FIG. In addition,
In these cases, if the cooling fan 22 has been stopped until then, the cooling fan 22 is set to the initial rotation speed (NR
Rotate at 50% (0.5 NR [rpm]) of [rpm]).

Further, when the third thermistor 14c is set for temperature control, the temperature measured by the other two thermistors 14a and 14b is higher than the temperature measured by the third thermistor 14c by 10 degrees or more. When it becomes, the partition plate adjusting tool 26 is moved, and the reference line FC with respect to the partition plate adjusting tool 26 is P2 in FIG.
Move to the position. Also, the first thermistor 1
Only the temperature measured by 4a is the third thermistor 14
When the temperature is higher than the temperature measured by c by 10 degrees or more, the reference line FC with respect to the partition plate adjusting tool 26 is shown in FIG.
Move to the position of P4 of 0. In these cases, when the cooling fan 22 has stopped until then, the cooling fan 22 is set to the initial rotation speed (NR [rpm]).
At 50% (0.5 NR [rpm]).

Even if the rotation of the cooling fan 22 and the partition plate adjusting tool 26 are moved as described above, if there is a temperature distribution on the surface of the heat roll 9, the position of the partition plate adjusting tool 26 is left as it is. Then, the rotation speed of the cooling fan 22 is increased by 50% from the current value to increase the amount of cooling air.

Other configurations and operations in the third embodiment are the same as those in the first embodiment, and therefore the description thereof will be omitted.

[0097]

According to the temperature control device for a heat roll of the present invention configured as described above, the heat roll partially becomes abnormally high temperature without stopping the engine to stop the power supply to the heat source. Can be prevented. Further, if the position where the cooling air is blown onto the heat roll can be changed, the occurrence of temperature distribution on the surface of the heat roll can be prevented.

[Brief description of drawings]

FIG. 1 is a side view of a laser beam printer to which a heat roll temperature control device according to a first embodiment of the present invention is applied.

FIG. 2 is a partial perspective view near the heat roll of FIG.

FIG. 3 is a flowchart showing a control process executed by the engine control unit of FIG.

FIG. 4 is a flowchart showing a control process executed by the engine control unit of FIG.

5 is a flowchart showing a control process executed by the engine control unit of FIG.

FIG. 6 is a flowchart showing a control process executed by an engine control unit according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a control process executed by an engine control unit according to the second embodiment of the present invention.

FIG. 8 is a flowchart showing a control process executed by an engine control unit according to a second embodiment of the present invention.

FIG. 9 is a plan view of a heat roll temperature control device according to a third embodiment of the present invention.

FIG. 10 is a plan view of the partition plate adjusting tool of FIG.

[Explanation of symbols]

 9 Heat Roll 12 Cooling Fan 14 Thermistor 15 Engine Control Section

Claims (18)

[Claims] 1. A temperature control device of a heat roll for fixing toner transferred onto paper by heat generated from a heat source provided inside, wherein the heat is used to measure the temperature on the surface of the heat roll. A plurality of temperature sensors arranged along the axial direction of the roll, a cooling fan for blowing cooling air to the heat roll, and a cooling air blown by the cooling fan based on the temperatures measured by the temperature sensors. A temperature control device for a heat roll, comprising: a control circuit for controlling the amount. 2. The plurality of temperature sensors are arranged at least near the center of the heat roll and near one end of the heat roll, and the cooling fan blows cooling air to both ends of the heat roll. The temperature is measured by a temperature sensor arranged near the end of the heat roll is higher than the temperature measured by a temperature sensor arranged near the center of the heat roll. The heat roll temperature control device according to claim 1, wherein the amount of cooling air from the cooling fan is increased. 3. The temperature control device for a heat roll according to claim 2, wherein the cooling fans are arranged near both ends of the heat roll. 4. The cooling fan is provided in a plurality corresponding to each of the plurality of temperature sensors, and is provided in an area on the surface of the heat roll where the surface temperature is measured by the corresponding temperature sensor. The heat roll temperature control device according to claim 1, wherein cooling air is blown to each. 5. The control circuit, when the temperatures measured by the plurality of temperature sensors are not uniform, adjusts the amount of cooling air from the cooling fans so that the temperatures become uniform. The temperature control device of the heat roll according to claim 4. 6. The temperature control of a heat roll according to claim 4, wherein the plurality of temperature sensors and the cooling fan are arranged near the center of the heat roll and near both ends thereof. apparatus. 7. The heat roll according to claim 5, wherein the controller increases the amount of cooling air from a cooling fan corresponding to a temperature sensor measuring a temperature higher than the others. Temperature control device. 8. A temperature control device for a heat roll, which fixes toner transferred onto paper by heat generated from a heat source provided inside, a cooling fan for blowing cooling air to the heat roll, and And a control circuit for controlling the amount of cooling air by the cooling fan based on the width and the passing position on the surface of the heat roll. 9. The control circuit, when the width of the paper is narrower than a predetermined reference value, increases the amount of cooling air blown to a region on the surface of the heat roll where the paper does not pass. The temperature control device for a heat roll according to claim 8. 10. The temperature control device for a heat roll according to claim 9, wherein the cooling fan is arranged near the center of the heat roll and near both ends thereof. 11. The heat according to claim 10, wherein the control circuit further increases the amount of cooling air from the cooling fan when the thickness of the paper is equal to or larger than a predetermined reference value. Roll temperature control device. 12. The temperature control for heat control according to claim 1, wherein the control circuit increases the rotation speed of a cooling fan when the amount of the cooling air is increased. apparatus. 13. The heat roll according to claim 1, wherein the control circuit rotates a cooling fan in a stopped state when the amount of the cooling air is increased. Temperature control device. 14. A temperature control device of a heat roll for fixing toner transferred onto paper by heat generated from a heat source provided inside, wherein the heat is used to measure a temperature on a surface of the heat roll. A plurality of temperature sensors arranged along the axial direction of the roll, a cooling fan that blows cooling air to the heat roll, and cooling air by the cooling fan can be displaced to any part on the surface of the heat roll. And a control circuit that controls the guiding means based on the temperatures measured by the plurality of temperature sensors to displace the blowing position of the cooling air on the surface of the heat roll. A heat roll temperature control device. 15. The plurality of temperature sensors are arranged near the center of the heat roll and near both ends thereof, and the control circuit is configured so that the temperatures measured by the plurality of temperature sensors are not uniform. 15. The temperature control device for the heat roll according to claim 14, wherein the blowing position of the cooling air on the surface of the heat roll is displaced so that the temperature becomes uniform. 16. The heat roll temperature control device according to claim 14, wherein the guide means is a movable duct that guides the cooling air from the cooling fan onto the surface of the heat roll. . 17. The cooling fan controls each of the cooling fans so that the temperature falls within the predetermined range when the temperature measured by any of the temperature sensors exceeds a predetermined range. 5. The temperature control device for a heat roll according to claim 4, wherein the amount of cooling air generated by the device is adjusted. 18. The heat roll temperature control device according to claim 17, wherein the plurality of temperature sensors and the cooling fan are arranged near the center of the heat roll and near both ends thereof.