JP2001264192A - Method and instrument for measuring pressure and method for adjusting pressure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an instrument for pressure measurement which speedily and accurately measure the pressure balance between a couple of pressure rollers in a practical use state and a method for pressure adjustment which adjusts the pressure between the pressure roller couple. SOLUTION: Stripped sheets 22a, 22b, and 22c connected to three torque gauges 20a, 20b, and 20c are arranged on an insertion table 2 and clamped between a couple of heat rollers 6 and 7 which are rotating; and the pressure between the heat rollers 6 and 7 is measured in real time from the measured value of a torque gauge 20 and adjusted by pressure adjustment parts 10a and 10b so that the pressure balance becomes uniform, and then the pressure balance can be measured and adjusted in real time, so that the measurement and adjustment time will be shortened. The measurement and adjustment can accurately be performed even when the heat rollers 6 and 7 are heated up to the temperature of practical use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure measuring method and a pressure measuring device for measuring a pressure of a pair of pressure rollers for sandwiching and pressing a sheet on which an image is to be transferred, and a pressure adjusting method for adjusting the pressure of the pair of pressure rollers.

[0002]

2. Description of the Related Art In recent years, an image recording apparatus using a heating head such as a laser beam or a thermal head has been used to thermally transfer a heat-sensitive material to an image receiving sheet in accordance with image information. 2. Description of the Related Art A system is used in which an image formed on an image receiving sheet is transferred to a sheet of paper to obtain an image on the sheet of paper.

An example of the image transfer apparatus will be described with reference to FIGS. 5 is a perspective view of the image transfer device, FIG. 6 is a sectional view of the image transfer device.

[0004] In the image transfer apparatus 1, the image receiving sheet 12 on which an image has been thermally transferred by the image recording apparatus and the book paper 14 are placed on the insertion table 2, and inserted into the entrance of the protective cover 5 while overlapping. When the roller is further inserted, it passes through the entrance of the heat cover 4 for preventing heat dissipation of the heating rollers 6 and 7 and reaches the rotating heating roller pair 6 and 7. The sheet 14 is sent to the conveying roller pairs 8 and 9 while being heated and pressed.

Next, the heated and pressurized image-receiving sheet 12 and the paper 14 are nipped by the conveying roller pairs 8 and 9 and are carried out to the carry-out stand 3. When the paper 14 and the image receiving sheet 12 carried out to the carry-out stand 3 are peeled off, the paper 14 is removed from the image receiving sheet 12.
The transferred image is obtained.

The heating rollers 6 and 7 are made of, for example, an aluminum material or the like, the outer periphery is covered with, for example, silicon rubber or the like, and a heater is provided in the center. Although not shown, the heating roller pairs 6 and 7 and the transport roller pairs 8 and 9 are rotationally controlled by a driving unit. For example, the heating roller 7 is a driving roller and the other heating roller 6 is a driven roller. I have. In addition, the pressure adjusting unit 10 includes heating rollers 6 and 7.
It has a function of adjusting the pressure between the rollers by a spring or the like, and is provided at both ends in the axial direction of the heating rollers 6 and 7.

However, if the balance between the pressure between the heating roller pairs 6 and 7 along the axial direction of each of the heating rollers 6 and 7 is not uniform, the heating between the heating roller pairs 6 and 7 is heated. The pressure is not evenly applied to the image-receiving sheet 12 and the paper 14 that pass while being pressed, and uneven transfer occurs to cause uneven transfer.
This causes a problem that an image cannot be accurately transferred from the image receiving sheet 12 to the real paper 14 due to wrinkles. Therefore, accurate measurement and adjustment of the pressure of the heating roller pair 6 and 7 are required.

Conventionally, the pressure of the heating roller pairs 6 and 7 is measured by applying a pressure measurement film (such as a prescale manufactured by Fuji Photo Film Co., Ltd.) whose color density changes in accordance with the pressure to the heating roller pairs 6 and 7. There is a method of measuring the pressure by sandwiching and rotating and passing the heating roller pairs 6 and 7,
Since the difference between the fluctuations in the circumferential direction of the roller surface (intra-peripheral fluctuation) in each of the heating rollers 6 and 7 is ignored, the accuracy of the pressure measurement cannot be improved.

The pressure measurement of the heating roller pair 6, 7 is
Since there is a change in the outer shape due to the thermal expansion of the heating roller, it is necessary to measure the pressure under the conditions actually used, for example, a predetermined high temperature state, but a pressure measurement film such as a prescale cannot be used in the high temperature state. .

Further, when the pressure is measured by the pressure measurement film, the pressure distribution displayed on the pressure measurement film after passing through the heating roller pairs 6 and 7 is checked, and then the heating roller pair 6 is controlled by the pressure adjusting unit 10. , 7 pressure adjustment, it is not possible to adjust the pressure in real time, and the pressure measurement film must be repeatedly passed through the heating roller pair 6, 7 to adjust the pressure. Poor adjustment efficiency.

As another pressure measuring method, as shown in FIG. 7, a pressure measuring sheet 1 having a piezoelectric element 102 between the heating roller pairs 6, 7 while rotating the heating roller pairs 6, 7 is used.
There is a method of measuring the pressure from the output of the piezoelectric element 102 with a measuring device (not shown) with the output of the piezoelectric element 102 interposed therebetween. According to this method, it is possible to measure the pressure in real time, but there remain problems such as the difference in the fluctuation of the circumference of the heating roller is ignored, and it cannot be used in a high temperature state of actual use. ing.

FIG. 8 shows another pressure measuring method.
As shown in the figure, a portion of the strip sheet 104 made of stainless steel, polyimide or the like is sandwiched between the stationary heating roller pairs 6 and 7,
The portion of the strip sheet not sandwiched is torque gauge 10
3 and pulling out the torque gauge 103, the pulling force when pulling out the strip sheet 104 from the pair of heating rollers 6 and 7 is measured by the torque gauge 103. There is a method of measuring the frictional force between the pair of rollers 6 and 7 and the strip sheet 104, which is proportional to the pressure of the pair of heating rollers 6 and 7 by the pulling force.

However, according to this pressure measuring method, although the pressure of the heating roller pairs 6 and 7 can be measured at the position where the strip sheet 104 is sandwiched, the pressure measurement over the entire circumference of the heating rollers 6 and 7 is performed by the heating roller pair 6 and 7. 7 must be rotated by a predetermined angle and stopped, and the pulling force must be measured in the same manner as described above, so that it takes time to measure the pressure. In addition, since measurements at a plurality of locations cannot be performed in parallel along the axial direction of the heating roller pairs 6 and 7, it takes more time for pressure measurement and pressure adjustment.

[0014]

For the above reasons, the pressures at a plurality of points in the axial direction of the heating roller pairs 6 and 7 are
A pressure measurement method that can accurately measure in real time while rotating, and that can measure even when the heating roller pair 6, 7 is at a predetermined high temperature in actual use, and a heating roller based on the pressure measured by the pressure measurement method. There has been a demand for a pressure adjustment method capable of performing the pressure adjustment of pairs 6 and 7 in a short time.

The present invention has been made in view of such a situation, and a pressure measuring method and a pressure measuring device for quickly and accurately measuring the pressure balance of a pair of pressure rollers in an actual use state, and a pressure roller. An object of the present invention is to provide a pressure adjustment method for performing pressure adjustment of a pair.

[0016]

According to a first aspect of the present invention, there is provided a pressure measuring method, wherein a pressure roller pair is pressed and rotated to connect three or more strip sheets to a torque gauge. The sheet and the torque gauge are arranged at a plurality of locations that are different from each other in the axial direction of the pressure roller pair, and each strip sheet is sandwiched between the pressure roller pairs,
The pressure of the pressure roller pair is measured by each of the torque gauges.

According to this pressure measuring method, the pressure roller pair is rotated while pinching three or more strip sheets, and the force with which the plurality of strip sheets are drawn into the pressure roller pair is measured by a torque gauge, whereby the pressure is measured. Since the pressure of the roller pair is measured, the fluctuation in the circumference can be measured in real time, and the pressure can be accurately measured. In addition, since measurement is performed at a plurality of locations by using three or more strip sheets, the pressure balance of the pressure roller can be measured in a short time.

The pressure roller pair is a heating roller pair capable of heating at a predetermined temperature.

According to this pressure measuring method, when the pressure roller is a heating roller, it can be heated at a predetermined temperature in accordance with the actual use conditions. The exact pressure of the heated roller pair under the condition can be measured.

According to the third aspect of the present invention, there is provided a pressure adjusting method.
Or the pressure of the pressure roller pair is measured by the pressure measurement method according to 2, and the pressure of the pressure roller pair is adjusted by pressure adjusting means at both axial ends of the pressure roller based on the obtained pressure. I do.

According to this pressure adjusting method, the pressure of the pressure roller pair is measured by the pressure measuring method, and the pressure adjusting means at both ends in the axial direction of the pressure roller can be adjusted by looking at the measured value. , The pressure on the image receiving sheet and the paper inserted between the pressure roller pair becomes uniform,
Non-uniform transfer due to uneven transfer is also eliminated. Further, the image receiving sheet and the paper can be accurately transferred from the image receiving sheet 12 to the paper 14 without wrinkles. In addition, since the adjustment can be performed while checking the measured value in real time, the adjustment time can be reduced.

According to a fourth aspect of the present invention, there is provided a pressure adjusting method according to the third aspect.
After the pressure adjustment by the pressure adjustment method of, passing a thin sheet between the pressure rollers while rotating the pressure roller pair,
Adjusting the pressure of the pair of pressure rollers corresponding to the wrinkled area among the plurality of areas different in the axial direction of the pressure roller of the thin sheet by the pressure adjusting means so that the axial pressure balance is uniform. It is characterized by.

According to this pressure adjusting method, the thin sheet is passed between the pressure rollers, and the pressure of the pressure roller pair corresponding to the wrinkled area among the plurality of areas different in the axial direction of the pressure roller of the thin sheet passing through the thin sheet. Since the adjustment is performed, it is possible to adjust the pressure of the pressure roller pair by checking the pressure actually applied to the thin sheet by using wrinkles.

According to a fifth aspect of the present invention, there is provided a pressure measuring apparatus for measuring the pressure of a pair of pressure rollers rotating by pressing by sandwiching a strip sheet connected to a torque gauge. 3 arranged at a plurality of different positions in the axial direction of the pressure roller pair
It is characterized by having at least one strip sheet.

According to this pressure measuring device, the pressure of the rotating pressure roller pair is measured by using three or more strip sheets arranged at a plurality of positions different from each other in the axial direction of the pressure roller pair. Therefore, the pressure balance can be measured in real time.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a pressure measuring method, a pressure measuring device and a pressure adjusting method according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view when the pressure measuring device of the present invention is installed in an image transfer device, and FIG.
FIG. 3 is a top view showing the arrangement of the pressure measuring device.

The image transfer device 1 includes a pair of heating rollers 6 and 7 that can be rotated and heated and pressed, a heat cover 4 that covers the pair of heating rollers 6 and 7, and a sheet that is sent from the pair of heating rollers 6 and 7. Conveying roller pairs 8, 9 for conveying the paper to the carry-out table 3.
A protective cover 5 for covering the heat cover 4 and the transport rollers 8 and 9; and an insertion table 2 for inserting a sheet or paper.
A discharge table 3 for discharging the sheet or paper conveyed by the heating roller pairs 6 and 7 and the conveyance roller pairs 8 and 9; and a pressure adjustment unit serving as pressure adjustment means for adjusting the pressure between the heating roller pairs 6 and 7. 10.

The pressure adjusting unit 10 includes a pair of heating rollers 6 and 7.
And has a function of adjusting the pressure between the heating rollers 6 and 7 using an elastic body such as a spring, but other means may be used as long as the pressure can be adjusted.

The pressure measuring device comprises a torque gauge 20 fixed to the insertion table 2 by a fixing portion 24, and a strip sheet 22 connected to the torque gauge, and the strip sheet 22 is connected to the torque gauge 20. The other side is sandwiched between the heating roller pairs 6 and 7.

Also, the torque gauge 20a and the strip sheet 2
2a, the torque gauge 20b and the strip sheet 22b, and the torque gauge 20c and the strip sheet 22c
7 are arranged at different positions in the axial direction, and each torque gauge is fixed to the insertion table 2. Of course, at different positions in the axial direction of the heating roller pairs 6 and 7, three or more torque gauges 20 and strip sheets 22 may be arranged on the insertion table 2. As an example, the material of the strip sheet is polyimide, and the size is 0.2 mm in thickness and 5 mm in width.

Next, the pressure measurement of the heating roller pairs 6 and 7 will be described in detail. As described above, the three torque gauges 20 and the strip sheet 22 are arranged on the insertion table 2, and the strip sheet 22 is sandwiched between the heating roller pairs 6, 7, and the heating roller pair 6,
7 is pressed by the pressure adjustment unit 10 at a preset pressure while rotating and heating in the same manner as when conveying a sheet or paper.

In this case, for example, the rotation speed of the heating roller pair 6, 7 is in the range of 2 to 20 seconds / time, and the temperature of the roller surface is 100 ° C. for the heating roller 6 and 110 ° C. for the heating roller 7.
It is assumed that the pressure initially set by the pressure adjusting unit 10 is 0.27 N / mm ² .

Each of the strip sheets 22a, 22b, and 22c sandwiched with the rotation of the heating roller pairs 6 and 7 is drawn in the transport direction (rightward in the drawing).
At 0a, 20b, and 20c, the values of the pull-in force at the portions where the respective strip sheets 22 are sandwiched are displayed, and the displayed values are in a cycle of one rotation according to the rotation of the heating roller pairs 6, 7. Each fluctuates.

Since the displayed value corresponds to the kinetic frictional force between the surfaces of the heating roller pairs 6 and 7 and the strip sheet 22, it is a value substantially proportional to the pressure between the heating roller pairs 6 and 7. The balance of pressure can be measured by the displayed value. For example, when the pressure at a certain position of the pair of heating rollers 6 and 7 is increased, the force for pulling the strip sheet 22 is increased, and the value displayed on the torque gauge 20 is also increased. Further, since the display value of the torque gauge 20 fluctuates in a cycle of one rotation, for example, a maximum value, a minimum value, an average value, or the like of the display values may be used as the measurement value of the pressure measuring device.

Accordingly, the measurement value can be obtained while the heating roller pairs 6 and 7 are rotating, so that the measurement can be performed in real time, and 3
Since the measurement is performed with the two torque gauges 20 arranged, the pressure balance between the heating roller pairs 6 and 7 can be quickly and simultaneously measured.

Next, each of the torque gauges 20a, 20b, 2
An adjustment method of the pressure adjustment unit 10 based on the measured value of 0c will be described. The adjustment of the pressure adjustment unit 10 is performed by adjusting the pressure adjustment units 10a and 10b so as to balance the pressures of the heating roller pairs 6 and 7 in the axial direction based on the measured values. Table 1 shows an example of a specific adjusting method of the pressure adjusting units 10a and 10b.

[0037]

[Table 1]

In Table 1, each torque gauge 20a, 2
The columns of 0b and 20c show the measured values, which are classified into three stages of "low", "medium", and "high" according to the values of the measured values. "Low" indicates that the measured value is low (low pressure), and "high" indicates that the measured value is high (high pressure). The columns of the pressure adjusting units 10a and 10b indicate the measured torque gauges 20.
3 shows how the pressures of the pressure adjusting units 10a and 10b are adjusted and the pressure is balanced by the measured values of the pressure adjustment unit 10a.
(The difference between the measured values of the torque gauges 20 when the pressure balance is made uniform is, for example, ± 0.01 N / mm ^2. )

The case of No. 1 in Table 1 will be described as an example. The measured values of the torque gauges 20a and 20b are "low",
Only the measured value of the torque gauge 20c is “high”. Accordingly, the pressure balance of the heating roller pair 6 and 7 can be made uniform by reducing the pressure of the pressure adjusting unit 10b on the side closer to the torque gauge 20c.

In the case of No. 2, the torque gauge 20a
Is "low", the torque gauge 20b is "medium", and the torque gauge 20c is "high". Therefore, the pressure of the pressure adjusting section 10a on the side close to the torque gauge 20a is increased, and the torque gauge 2
By reducing the pressure of the pressure adjustment unit 10b on the side closer to 0c, the pressure balance between the heating roller pairs 6 and 7 can be equalized.

Next, in the case of No. 4, only the torque gauge 20b is "high" and the other torque gauges are "low". This is because the heating roller pair 6, 7 is the measuring point of the torque gauge 20b.
At the central part in the 7-axis direction, the heating rollers 6 and 7 are bent with respect to each other or one of them, and the heating roller pairs 6 and 7
This is the state where the pressure between them is high. FIG. 3 shows, as an example, a state in which only the heating roller 6 is bent when viewed from the side where the strip sheet 22 is inserted.

Therefore, in this case, the pressure adjusting unit 10 is adjusted by increasing the pressure of both the pressure adjusting units 10a and 10b, and setting the heating roller pairs 6 at the measurement locations of the torque gauges 20a and 20c.
The pressure balance between the heating roller pairs 6 and 7 can be made uniform by increasing the pressure between the heating rollers 7.

Here, the adjustment time when the pressure balance is adjusted based on the measurement performed by one torque gauge 103 and the strip sheet 104 without rotating the heating roller, which is a conventional pressure measurement method, is one hour. However, according to the pressure adjustment method of the present invention, the time required for the adjustment was about 10
Minutes, and the adjustment time was greatly reduced.

After the pressure balance of the heating roller pairs 6 and 7 is adjusted by the adjustment of the pressure adjusting unit 10 described above, the thin sheet is further passed through the heating roller pairs 6 and 7 and, depending on the state of the thin sheet that has passed therethrough, In some cases, the pressure adjustment unit 10 may be adjusted.

The adjusting method using the thin sheet will be described. As described above, after the pressure balance is adjusted by the pressure adjusting unit 10 based on the measured value of the pressure by the torque gauge 20 and the strip sheet 22, the heating roller pair 6 is again adjusted. 7 is rotated and heated in the same manner as the actual use condition, and then the thin sheet 16 is inserted into the image transfer device 1 from the insertion table 2.

Heating roller pairs 6, 7 and conveying roller pairs 8, 9
Is discharged to the discharge table 3. FIG. 4 is a view of the state of the thin sheet 16 discharged onto the discharge table 3 as viewed from above the image transfer apparatus 1. According to the example shown in the drawing, wrinkles are formed in a part (the right side as viewed from the insertion direction) of the discharged thin sheet 16, which is caused by the heating roller pairs 6 and 7 in the portion where the wrinkled area has passed. It has been found that wrinkles occur because the pressure is high and the pressure balance is not uniform.

Therefore, if the pressure of the heating roller pair 6 and 7 corresponding to the wrinkled area is reduced by the pressure adjusting unit 10, the pressure balance can be made uniform. That is, in this case, if the area of the thin sheet 16 is divided into, for example, three areas in the axial direction of the heating roller pairs 6 and 7,
Since the wrinkled area (right side) is close to the pressure adjusting unit 10b, the pressure balance of the heating roller pair 6, 7 can be made uniform by reducing the pressure of the pressure adjusting unit 10b. Table 2 shows the pressure adjuster 10 for wrinkles of the thin sheet 16.
An example of an adjustment method for a and 10b will be described.

[0048]

[Table 2]

Table 2 shows how the pressures of the pressure regulators 10a and 10b are adjusted to balance the pressure depending on whether or not each area of the thin sheet 16 discharged from the image transfer apparatus 1 has wrinkles. ing.

The case of No. 1 in Table 2 will be described as an example. Since only the right side area of the thin sheet 16 has wrinkles,
By lowering the pressure of the pressure adjusting unit 10b on the side closer to the right area, the pressure balance between the heating roller pairs 6 and 7 can be equalized.

In the case of No. 3, wrinkles are present only in the central region of the thin sheet 16, but this is because the heating rollers 6 and 7 are deflected to each other or one of them in the central portion in the axial direction. Since the pressure between the heating roller pairs 6 and 7 is high at the central portion, the pressure is increased in both of the pressure adjusting units 10a and 10b, and the pressure between the heating roller pairs 6 and 7 with respect to the left and right sides of the thin sheet 16 is increased. By increasing the pressure, the pressure balance between the heating roller pairs 6 and 7 can be equalized.

A specific example of the thin sheet 16 is a paper having a basis weight of about 90 g / m 2 or less. Further, the number of different regions in the axial direction of the heating roller pairs 6 and 7 of the thin sheet 16 may be other than three, and the width of the region may be set arbitrarily within a range that does not hinder the pressure measurement.

In the above embodiment, the image transfer apparatus 1 including the heating roller pairs 6 and 7 and the pressure adjusting unit 10 and the image recording apparatus are provided separately, but the pressure measuring method, the pressure measuring apparatus and the pressure The adjustment method can be applied to a case where the image recording apparatus and the image transfer apparatus 1 are integrated.

[0054]

According to the pressure measuring method of the present invention, three or more strip sheets are sandwiched while the pressure roller pair rotates, and the force with which the plurality of strip sheets are drawn into the pressure roller pair is measured by a torque gauge. By measuring the pressure of the pressure roller pair, the fluctuation in the circumference can be measured in real time,
The pressure can be measured accurately. In addition, since measurement is performed at a plurality of locations by using three or more strip sheets, the pressure balance of the pressure roller can be measured in a short time in parallel.

Further, when the pressure roller is a heating roller, the heating roller can be heated at a predetermined temperature in accordance with the actual use condition. An accurate pressure can be measured.

Further, the pressure of the pressure roller pair is measured by the pressure measurement method, and the pressure adjustment means at both ends in the axial direction of the pressure roller can be adjusted by referring to the measured value. The pressure on the image receiving sheet and the actual paper inserted into the sheet becomes uniform, and the transfer is not uneven due to uneven transfer. Further, the image receiving sheet and the paper can be accurately transferred from the image receiving sheet 12 to the paper 14 without wrinkles. In addition, since the adjustment can be performed while checking the measured value in real time, the adjustment time can be reduced.

The basis weight between the pressure rollers is approximately 90 g / m
^Since the pressure of the pressure roller pair corresponding to the wrinkled area is adjusted among the three equal areas in the pressure roller axial direction of the passed paper through ² or less papers,
It is possible to adjust the pressure of the pressure roller pair by checking the pressure actually applied to the paper by wrinkles.

[0058]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a pressure measuring device according to the present invention.

FIG. 2 is a top view showing the configuration of the pressure measuring device of the present invention. .

FIG. 3 is a configuration diagram showing a state in which a heating roller 6 is bent.

FIG. 4 is a top view showing a state of a thin sheet 16 discharged onto a discharge table 3;

FIG. 5 is a perspective view illustrating a configuration of an image transfer device.

FIG. 6 is a cross-sectional view illustrating a configuration of an image transfer device.

FIG. 7 shows a pressure measurement sheet 1 in a conventional pressure measurement method.
It is a perspective view at the time of using 00.

FIG. 8 shows a torque gauge 10 in a conventional pressure measuring method.
FIG. 3 is a perspective view when No. 3 is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image transfer apparatus 2 Insertion stand 3 Discharge stand 4 Heat cover 5 Protective cover 6, 7 Heating roller 8, 9 Conveyance roller 10 Pressure adjustment part 12 Image receiving sheet 14 Book paper 16 Thin sheet 20, 103 Torque gauge 22, 104 Strip sheet 100 Pressure Measurement sheet 102 Piezoelectric element

Claims (5)

[Claims] 1. A pressure roller pair is pressed and rotated to connect three or more strip sheets to a torque gauge, respectively, and the strip sheet and the torque gauge are placed at a plurality of positions which are different from each other in the axial direction of the pressure roller pair. A pressure measuring method, comprising: arranging the strip sheets between the pressure roller pairs, and measuring the pressure of the pressure roller pairs by the torque gauges. 2. The method according to claim 1, wherein the pair of pressure rollers is a pair of heating rollers capable of heating to a predetermined temperature. 3. The pressure measuring method according to claim 1, wherein the pressure of the pressure roller pair is measured, and based on the obtained pressure, the pressure adjusting means at both ends in the axial direction of the pressure roller is used to control the pressure roller pair. A pressure adjusting method comprising adjusting pressure. 4. After the pressure is adjusted by the pressure adjusting method according to claim 3, a thin sheet is passed between the pressure rollers while rotating the pair of pressure rollers, and a plurality of regions of the thin sheet differing in the pressure roller axial direction are provided. A pressure adjusting method, wherein the pressure of the pair of pressure rollers corresponding to the wrinkled area is adjusted by the pressure adjusting means so that an axial pressure balance is uniform. 5. A pressure measuring device for measuring the pressure of a pair of pressure rollers being pressed and rotated by sandwiching a strip sheet connected to a torque gauge, wherein the pressure measurement device is connected to a torque gauge and varies in the axial direction of the pressure roller pair. A pressure measuring device comprising three or more strip sheets arranged at a plurality of positions.