JP2000122461A - Image forming device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device and the method therefor making the surface temp. of a fixing roller possible to be uniformly and quickly raised to the fixing temp. by controlling the rotation of the fixing roller at the warming-up time. SOLUTION: The image recording device 1 is, when power is turned on, allowed to start for heating the fixing roller by starting conduction to a heating member 34 by the fixing roller temp. controlling part 40, to let the fixing roller drive motor 43 rotary driven through the motor driver 42 by the rotary speed controlling part 41, and to let the fixing roller rotary driven at the warming-up time rotary speed that is slower than the fixing time rotary speed by the specified speed. The rotary speed controlling part 41 is, when the surface temp. of the fixing roller detected by the temp. detecting sensor 35 reaches the rotation changing temp. that is lower than the fixation the temp., allowed to rotary-drive the fixing roller at the fixing time rotary speed by controlling the motor driver 42. Therefore, the surface of the fixing roller is quickly raised to the temp. for fixing, being free from unevenness in the temp. distribution, and prevented from overshooting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image fixing apparatus and an image fixing method, and more particularly, to an image recording apparatus of an electrophotographic system or the like. The temperature of the fixing roller is controlled by controlling the rotation speed of the fixing roller and the pressure roller when the toner image attached to the paper is heated and pressed by the rotating fixing roller and the pressure roller to fix it on the transfer paper. The present invention relates to an image fixing device and an image fixing method that are appropriately performed.

[0002]

2. Description of the Related Art Conventionally, as a method for fixing a toner image formed on transfer paper (recording paper) such as paper or film, generally, heating and pressing are performed to melt the toner and fix the toner onto the recording paper. A fixing method is used, and among the heat fixing methods, the heat roller method is most widely used because of its high thermal efficiency and high safety.

In this heat roller system, at least one of two pressed rollers is heated, and a transfer sheet having unfixed toner adhered to a pressed portion (nip portion) of the two rollers is heated and pressed. Then, the toner is fixed on the transfer paper. When heating one of these two rollers, the roller to be heated is generally called a fixing roller, and the other roller is generally called a pressure roller. Conventionally, a temperature sensor is attached to the outer surface of the fixing roller, and the amount of power supplied to the heat source is controlled so that the temperature of the nip is maintained at a temperature suitable for fixing. And
Conventionally, the fixing roller generally has a built-in halogen lamp, and is generally heated to a fixing temperature at which the toner as a developer on the transfer paper is melted and fixed by the halogen lamp.

In such an image fixing device of the heat roller type, it takes several minutes for the fixing roller to rise to the fixing temperature required for melting the developer, so that the rise time is shortened. Is an important issue.

That is, when the temperature of the fixing roller rises to a temperature necessary for melting the developer, it is known that the temperature rising time greatly varies depending on the amount of heat taken by the pressure roller pressed against the fixing roller. The amount of heat taken by the pressure roller is more remarkable as the pressure contact portion (nip portion) between the fixing roller and the pressure roller is larger, but if the nip portion is smaller, the amount of heat required for fixing at the time of fixing is reduced. It may not be sufficiently transmitted to the unfixed toner image on the transfer paper, and a fixing failure may occur.

Conventionally, in an image fixing device,
After the power is turned on, the rotation control of the fixing roller and the pressure roller until the temperature of the fixing roller is raised to the fixing temperature is generally performed by the following two methods.

[0007] 1. A method in which the fixing roller and the pressure roller are rotated at the fixing rotational speed immediately after the power is turned on.

[0008] 2. After the power is turned on, the fixing roller and the pressure roller are stopped until the surface temperature of the fixing roller reaches a predetermined temperature, and then the fixing roller and the pressure roller are rotated at the rotation speed at the time of fixing.

When the rotation of such a conventional fixing roller and pressure roller is controlled, the surface temperature of the fixing roller becomes as shown in FIG.
5 and FIG.

That is, in the rotation method of rotating at the rotation speed at the time of fixing from the beginning, as shown in FIG. 15, the surface temperature of the fixing roller quickly becomes a uniform temperature distribution. It takes a relatively long time to raise the temperature. Further, in the rotation method of stopping the rotation in the above 2, as shown in FIG. 16, unevenness occurs in the temperature distribution on the surface of the fixing roller, and a certain portion quickly rises to the fixing temperature, but the entire surface of the fixing roller is heated. To increase the fixing temperature,
Not only does it take a relatively long time, but also a large overshoot occurs in the fixing roller surface temperature.

Conventionally, the rotation control of a fixing roller and a pressure roller in an image fixing device is disclosed in, for example,
Japanese Patent Application Laid-Open No. 88572/8857 proposes an image fixing method. The image fixing method includes a first speed during the fixing operation and a second speed during the standby as rotation speeds of the fixing roller and the pressure roller. And three modes of a third speed set lower than the first speed and higher than the second speed, and when the surface temperature of at least one of the rollers is lower than a predetermined first temperature when the power is turned on. The roller is rotated at a first speed until the surface temperature of the roller reaches a predetermined second temperature by heating after the power is turned on. During the period, the roller is rotated at the third speed, and thereafter, the roller is rotated at the second speed.

An image fixing method disclosed in Japanese Patent Application Laid-Open No. 5-88582 has been proposed. In this image fixing method, a rotation speed of a roller includes a first speed during a fixing operation, and a standby speed. And a third speed set at a speed lower than the first speed and higher than the second speed, wherein at least one surface temperature of the roller is a predetermined first temperature after power-on. Between the first temperature and the second temperature set higher than the first temperature, the roller is rotated at the first speed, and the time from when the surface temperature of the roller reaches a second temperature from a predetermined point in time after the power is turned on. If exceeds a predetermined time, after reaching the second temperature,
Unless there is a print command, the third
The roller is rotated at the speed, and thereafter the roller is rotated at the second speed.

[0013] In any of the above-mentioned conventional image fixing methods, the purpose is to prevent the temperature of the roller from dropping abruptly when the roller is rotated at the end of the warming-up, so that the surface of the roller is turned on after the power is turned on. Until the temperature reaches the second temperature, the rotation is performed at the first speed which is the rotation speed at the time of fixing, and then the third speed and the second speed which are lower than the first speed are performed.
Rotating at speed.

[0014]

However, in such a conventional image fixing method, the first speed, which is the rotation speed at the time of fixing, until the surface temperature of the roller reaches the second temperature after the power is turned on. And then at a third speed and a second speed that are slower than the first speed, so that the surface temperature of the fixing roller quickly rises to the fixing temperature uniformly over the entire surface of the fixing roller. It was a problem.

That is, in the above-described conventional method, since the roller is rotated at the rotation speed during fixing until the predetermined temperature after the power is turned on, the temperature distribution on the surface of the fixing roller shown in FIG. Although this can be prevented, there is a problem that it takes a long time for the fixing roller to rise to the fixing temperature because the roller is rotated at a relatively high rotation speed at the time of fixing.

Therefore, according to the present invention, a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressure roller pressed against the fixing roller are rotationally driven at a predetermined fixing rotation speed, When fixing the toner image on the transfer paper while transporting the transfer paper on which the toner image has been transferred while holding the transfer paper with the fixing roller and the pressure roller rotated, the warm-up until the temperature of the fixing roller rises to the fixing temperature During this time, the rotation speed control means controls the rotation speeds of the fixing roller and the pressure roller to a predetermined speed lower than the rotation speed during fixing until the surface temperature of the fixing roller reaches a rotation switching temperature lower by a predetermined temperature than the fixing temperature. By rotating at a slow rotation speed during warm-up, and then rotating at a fixing speed, it is possible to suppress unevenness in temperature distribution on the surface of the fixing roller, In addition to raising the surface temperature of the fixing roller to the fixing temperature, the waiting time at startup is reduced, the power consumption is reduced, the operating cost is reduced, and the fixing quality is prevented and the image quality is improved. It is an object of the present invention to provide an image fixing device that can perform the fixing.

According to a second aspect of the present invention, a toner image is formed by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressing roller pressed against the fixing roller at a predetermined rotation speed during fixing. When fixing the toner image on the transfer paper while nipping and transferring the transferred transfer paper by the fixing roller and the pressure roller driven by rotation, at the time of warming up until the temperature of the fixing roller rises to the fixing temperature, From the start of warm-up until a predetermined time elapses,
By the rotation speed control means, the rotation speed of the fixing roller and the pressure roller is driven to rotate at a warming-up rotation speed that is a predetermined speed lower than the rotation speed at the time of fixing, and thereafter, the rotation speed is driven at the fixing speed. While suppressing unevenness of the temperature distribution on the surface of the fixing roller, the surface temperature of the fixing roller is quickly raised to the fixing temperature, the waiting time at the start-up is reduced, the power consumption is reduced, and the operating cost is reduced. It is another object of the present invention to provide an inexpensive image fixing device capable of preventing uneven fixing and improving image quality.

According to a third aspect of the present invention, a toner image is formed by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressure roller pressed against the fixing roller at a predetermined rotation speed during fixing. When fixing the toner image on the transfer paper while nipping and transferring the transferred transfer paper by the fixing roller and the pressure roller driven by rotation, at the time of warming up until the temperature of the fixing roller rises to the fixing temperature, Until the rotation speed of the fixing roller reaches the predetermined rotation speed, the rotation speed control unit rotates the rotation speed of the fixing roller and the pressure roller at the warming-up rotation speed that is lower than the rotation speed during fixing by a predetermined speed. Then, by rotating the fixing roller at the fixing speed, the surface temperature of the fixing roller quickly rises to the fixing temperature while suppressing the unevenness of the temperature distribution on the fixing roller surface. The purpose of the present invention is to provide an image fixing device that can reduce the waiting time at the time of startup, reduce power consumption, reduce operation costs, prevent uneven fixing, and improve image quality. I have.

According to a fourth aspect of the present invention, when the rotation speed of the fixing roller and the pressure roller is changed from the rotation speed at the time of warming-up to the rotation speed at the time of fixing, a predetermined number of rotation speeds between the rotation speed at the time of warming-up and the rotation speed at the time of fixing are changed. By changing the rotation speed stepwise and changing it continuously, or by changing it continuously, the rotation speed of the fixing roller is changed smoothly, and the occurrence of vibration due to the rapid change of the rotation speed is suppressed. It is an object of the present invention to provide an image fixing apparatus with reduced vibration capable of shortening a waiting time, reducing power consumption and operating costs, preventing fixing unevenness, and improving image quality.

According to a fifth aspect of the present invention, by using a fixing roller in which a heat generating member is disposed in a layered form near the surface of the fixing roller, the surface of the fixing roller can be more quickly raised to the fixing temperature. An inexpensive image fixing device that can further reduce the waiting time at startup, further reduce the power consumption and further reduce the operation cost, and also prevent the fixing unevenness and improve the image quality. It is intended to provide.

According to a sixth aspect of the invention, a toner image is formed by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressure roller pressed against the fixing roller at a predetermined rotation speed during fixing. When fixing the toner image on the transfer paper while nipping and transferring the transferred transfer paper by the fixing roller and the pressure roller driven by rotation, at the time of warming up until the temperature of the fixing roller rises to the fixing temperature, Until the surface temperature of the fixing roller reaches a rotation switching temperature lower than the fixing temperature by a predetermined temperature, the rotation speed of the fixing roller and the pressure roller is driven at the warming-up rotation speed that is a predetermined speed lower than the fixing rotation speed. And then
By rotating at the fixing speed, the surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution on the fixing roller surface, shortening the waiting time at startup and reducing power consumption. It is another object of the present invention to provide an image fixing method capable of reducing operation costs, preventing uneven fixing, and improving image quality.

According to a seventh aspect of the present invention, a toner image is formed by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressure roller pressed against the fixing roller at a predetermined rotation speed during fixing. When fixing the toner image on the transfer paper while nipping and transferring the transferred transfer paper by the fixing roller and the pressure roller driven by rotation, at the time of warming up until the temperature of the fixing roller rises to the fixing temperature, From the start of warm-up until a predetermined time elapses,
The rotation speed of the fixing roller and the pressure roller is rotated at a warming-up rotation speed that is lower than the rotation speed at the time of fixing by a predetermined speed, and thereafter, the rotation speed is driven at the fixing speed. The surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing unevenness of the fixing roller, shortening the waiting time at startup, reducing power consumption and operating costs, and preventing fixing unevenness. It is another object of the present invention to provide an inexpensive image fixing method capable of improving image quality.

According to an eighth aspect of the present invention, a toner image is formed by rotating a fixing roller heated to a predetermined fixing temperature by a heat-generating member and a pressing roller pressed against the fixing roller at a predetermined rotation speed during fixing. When fixing the toner image on the transfer paper while nipping and transferring the transferred transfer paper by the fixing roller and the pressure roller driven by rotation, at the time of warming up until the temperature of the fixing roller rises to the fixing temperature, Until the rotation speed of the fixing roller reaches a predetermined rotation speed, the rotation speeds of the fixing roller and the pressure roller are rotated at a warming-up rotation speed that is lower than the rotation speed at the time of fixing by a predetermined speed. By rotating and driving, the surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution on the surface of the fixing roller,
It is an object of the present invention to provide an image fixing method capable of shortening a waiting time at start-up, reducing power consumption, reducing operation costs, preventing uneven fixing, and improving image quality.

According to a ninth aspect of the present invention, when the rotation speed of the fixing roller and the pressure roller is changed from the rotation speed at the time of warming-up to the rotation speed at the time of fixing, a predetermined number of rotation speeds between the rotation speed at the time of warming-up and the rotation speed at the time of fixing are provided. By changing the rotation speed stepwise and changing it continuously, or by changing it continuously, the rotation speed of the fixing roller is changed smoothly, and the occurrence of vibration due to the rapid change of the rotation speed is suppressed. It is an object of the present invention to provide a low-vibration image fixing method capable of shortening a waiting time, reducing power consumption and operating costs, preventing uneven fixing, and improving image quality.

According to a tenth aspect of the present invention, by using a fixing roller in which a heat generating member is disposed in a layered form near the surface of the fixing roller, the surface of the fixing roller can be raised to the fixing temperature more quickly. An inexpensive image fixing method that can further reduce the waiting time at startup, further reduce the power consumption, further reduce the operation cost, prevent the fixing unevenness, and improve the image quality. It is intended to provide.

[0026]

According to an aspect of the present invention, there is provided an image fixing apparatus comprising: a fixing roller which is heated to a predetermined fixing temperature by a heat generating member to fix a toner image transferred to a transfer sheet onto the transfer sheet; A pressure roller that presses the transfer sheet, onto which the toner image has been transferred, by pressing against the fixing roller, to press the transfer paper onto the fixing roller; a rotation driving unit that rotationally drives the fixing roller and the pressure roller; Rotation speed control means for controlling the rotation speed of the fixing roller and the pressure roller by means; temperature detection means for detecting the temperature of the fixing roller; and a heating element for the heating member based on a detection result of the temperature detection means. Temperature control means for controlling energization to heat the fixing roller to a predetermined fixing temperature, and at the time of fixing, the rotation speed control means through the rotation driving means. The fixing roller and the pressure roller heated to the fixing temperature are rotated at a predetermined fixing rotation speed, and the transfer paper on which the toner image is transferred is conveyed by the fixing roller and the pressure roller. An image fixing device for fixing the toner image on the transfer sheet, wherein the rotation speed control unit detects the temperature detected by the temperature detection unit during warm-up until the fixing roller is heated to the fixing temperature. Until the surface temperature of the fixing roller reaches a rotation switching temperature lower than the fixing temperature by a predetermined temperature, the rotation speeds of the fixing roller and the pressure roller are changed from the rotation speed at the time of fixing through the rotation driving unit. The above-described object is achieved by rotating the motor at a predetermined speed which is slower at the warming-up rotation speed and then rotating at the fixing speed. That.

According to the above configuration, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are rotationally driven at the predetermined rotation speed at the time of fixing to transfer the toner image. When the toner image is fixed on the transfer paper while being conveyed while being held between the rotating transfer roller and the pressure roller by the fixing roller and the pressure roller, at the time of warming-up until the temperature of the fixing roller rises to the fixing temperature, the fixing roller Until the surface temperature of the fixing roller reaches a rotation switching temperature lower than the fixing temperature by a predetermined temperature, the rotation speed of the fixing roller and the pressurizing roller is reduced by a predetermined speed lower than the fixing rotation speed by the rotation speed control means. The fixing roller is rotated at the fixing speed and then driven at the fixing speed. The surface temperature was raised to the fixing temperature,
The waiting time at the time of startup can be shortened, the power consumption can be reduced, the operation cost can be reduced, and the image quality can be improved by preventing the fixing unevenness.

According to a second aspect of the present invention, there is provided an image fixing apparatus comprising: a fixing roller which is heated to a predetermined fixing temperature by a heat generating member to fix a toner image transferred to a transfer sheet onto the transfer sheet; A pressure roller that presses the transfer paper on which the toner image is transferred to the fixing roller, a rotation driving unit that rotationally drives the fixing roller and the pressure roller, and the fixing roller that is driven by the rotation driving unit. A rotation speed control unit configured to control a rotation speed of the pressure roller, a temperature detection unit configured to detect a temperature of the fixing roller, and a power supply to the heating member based on a detection result of the temperature detection unit. A temperature control unit for heating and controlling the fixing roller to a predetermined fixing temperature, wherein at the time of fixing, the rotation speed control unit sets the fixing temperature to the fixing temperature via the rotation driving unit. By rotating the heated fixing roller and the pressure roller at a predetermined rotation speed at the time of fixing, the transfer paper on which the toner image has been transferred is conveyed by the fixing roller and the pressure roller, and the toner An image fixing device for fixing an image on the transfer paper, further comprising a time measuring means for measuring an elapsed time from the start of warming-up, wherein the rotation speed control means is provided until the fixing roller is heated to the fixing temperature. During warm-up,
From the start of the warm-up to the timing of the predetermined time from the start of the warm-up, the rotational speed of the fixing roller and the pressure roller via the rotational driving unit is set to a predetermined speed lower than the rotational speed at the time of the warm-up. Then, the above-mentioned object is achieved by performing the rotational driving at the fixing rotational speed.

According to the above construction, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressing roller pressed against the fixing roller are driven to rotate at the predetermined fixing rotation speed to transfer the toner image. When fixing the toner image on the transfer paper while transporting the transferred transfer paper sandwiched between the rotating fixing roller and pressure roller, the warming-up starts at the time of warming-up until the temperature of the fixing roller rises to the fixing temperature. Until a predetermined time elapses, the rotation speed control means drives the rotation speed of the fixing roller and the pressure roller to rotate at a warming-up rotation speed that is a predetermined speed lower than the rotation speed at the time of fixing, and then rotates at the fixing speed Driven quickly, fixing the surface temperature of the fixing roller quickly with a simple configuration while suppressing unevenness in the temperature distribution on the surface of the fixing roller. It is possible to reduce the waiting time at startup, reduce power consumption and reduce operating costs, and also prevent uneven fixing and improve image quality at low cost. it can.

According to a third aspect of the present invention, there is provided an image fixing apparatus comprising: a fixing roller which is heated to a predetermined fixing temperature by a heat generating member to fix a toner image transferred to a transfer sheet onto the transfer sheet; A pressure roller that presses the transfer paper on which the toner image is transferred to the fixing roller, a rotation driving unit that rotationally drives the fixing roller and the pressure roller, and the fixing roller that is driven by the rotation driving unit. A rotation speed control unit configured to control a rotation speed of the pressure roller, a temperature detection unit configured to detect a temperature of the fixing roller, and a power supply to the heating member based on a detection result of the temperature detection unit. A temperature control unit for heating and controlling the fixing roller to a predetermined fixing temperature, wherein at the time of fixing, the rotation speed control unit sets the fixing temperature to the fixing temperature via the rotation driving unit. By rotating the heated fixing roller and the pressure roller at a predetermined rotation speed at the time of fixing, the transfer paper on which the toner image has been transferred is conveyed by the fixing roller and the pressure roller, and the toner An image fixing device for fixing an image on the transfer paper, further comprising a rotation speed detecting unit that detects at least a rotation speed of the fixing roller, wherein the rotation speed control unit is configured to control the rotation speed of the fixing roller to the fixing temperature. During the warm-up period, the rotation speeds of the fixing roller and the pressure roller are set to be higher than the fixing rotation speed through the rotation drive unit until the rotation speed detection unit detects a predetermined rotation speed. When the rotation speed is reduced at the warming-up rotation speed and the rotation speed detection means detects a predetermined rotation speed,
The object is achieved by rotating the fixing roller and the pressing roller at the fixing rotation speed.

According to the above configuration, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressing roller pressed against the fixing roller are driven to rotate at the predetermined fixing rotation speed to transfer the toner image. When the toner image is fixed on the transfer paper while being conveyed while being held between the rotating transfer roller and the pressure roller by the fixing roller and the pressure roller, at the time of warming-up until the temperature of the fixing roller rises to the fixing temperature, the fixing roller Until the rotation speed of the fixing roller reaches the predetermined rotation speed, the rotation speed of the fixing roller and the pressure roller is rotated at a warming-up rotation speed lower by a predetermined speed than the fixing rotation speed by the rotation speed control unit, and thereafter, The fixing roller is rotated at the fixing speed, so that the surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution on the surface of the fixing roller. It is possible to shorten the waiting time of rising consumption with power can be reduced to reduce to operating costs, fixing unevenness is prevented, thereby improving the image quality.

In each of the above cases, for example, as described in claim 4, the rotation speed control means changes the rotation speed of the fixing roller and the pressure roller from the warming-up rotation speed to the fixing rotation speed. When changing the rotation speed, a predetermined number of rotation speeds between the warming-up rotation speed and the fixing rotation speed may be changed by changing stepwise, or may be changed continuously.

According to the above configuration, when changing the rotation speed of the fixing roller and the pressure roller from the rotation speed at the time of warming-up to the rotation speed at the time of fixing, a predetermined number of rotation speeds between the rotation speed at the time of warming-up and the rotation speed at the time of fixing are used. Is changed by changing stepwise or continuously, so that the rotation speed of the fixing roller can be smoothly changed to suppress the occurrence of vibration due to the rapid change of the rotation speed, and The waiting time can be shortened, the power consumption can be reduced, and the operating cost can be reduced. In addition, the image quality can be improved while preventing the uneven fixing and suppressing the vibration.

Further, for example, the fixing roller may be configured such that the heat-generating member is disposed in a layered form near the surface of the fixing roller.

According to the above configuration, since the heat generating member is used in the form of a layer disposed in the vicinity of the surface of the fixing roller as the fixing roller, the surface of the fixing roller is more quickly raised to the fixing temperature, The waiting time at startup can be further reduced, the power consumption can be further reduced, the operation cost can be further reduced, and the image quality can be improved inexpensively by preventing the fixing unevenness. it can.

According to a sixth aspect of the present invention, in the image fixing method, a fixing roller heated to a predetermined fixing temperature by a heating member and a pressure roller pressed against the fixing roller are rotationally driven at a predetermined fixing rotation speed. An image fixing method for fixing the toner image to the transfer paper while conveying the transfer paper on which the toner image is transferred while being held between the fixing roller and the pressure roller which are driven to rotate, wherein the fixing roller During the warm-up period until the temperature of the fixing roller rises to the fixing temperature, the rotation speeds of the fixing roller and the pressure roller until the surface temperature of the fixing roller reaches a rotation switching temperature lower by a predetermined temperature than the fixing temperature. By rotating at a warming-up rotation speed that is a predetermined speed lower than the fixing rotation speed, and then rotating at the fixing speed, It has achieved the serial purpose.

According to the above configuration, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are driven to rotate at the predetermined fixing rotation speed to transfer the toner image. When the toner image is fixed on the transfer paper while being conveyed while being held between the rotating transfer roller and the pressure roller by the fixing roller and the pressure roller, at the time of warming-up until the temperature of the fixing roller rises to the fixing temperature, the fixing roller Until the surface temperature of the fixing roller reaches the rotation switching temperature lower than the fixing temperature by a predetermined temperature, the rotation speed of the fixing roller and the pressure roller is rotationally driven at a warming-up rotation speed lower by a predetermined speed than the fixing rotation speed, After that, since it is driven to rotate at the fixing speed, the surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution on the surface of the fixing roller. By, it is possible to reduce the waiting time at the rising consumption with power can be reduced to reduce to operating costs, fixing unevenness is prevented, thereby improving the image quality.

According to a seventh aspect of the present invention, in the image fixing method, a fixing roller heated to a predetermined fixing temperature by a heating member and a pressure roller pressed against the fixing roller are rotationally driven at a predetermined fixing rotation speed. An image fixing method for fixing the toner image to the transfer paper while conveying the transfer paper on which the toner image is transferred while being held between the fixing roller and the pressure roller which are driven to rotate, wherein the fixing roller During a warm-up period until the temperature of the fixing roller rises to the fixing temperature, during a predetermined time from the start of the warm-up, the rotational speeds of the fixing roller and the pressure roller are set at a warm-up rotational speed lower than the rotational speed at the fixing by a predetermined speed. The above-mentioned object is achieved by rotating the lens and then rotating it at the fixing rotation speed.

According to the above arrangement, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are rotationally driven at the predetermined fixing rotation speed to transfer the toner image. When fixing the toner image on the transfer paper while transporting the transferred transfer paper sandwiched between the rotating fixing roller and pressure roller, the warming-up starts at the time of warming-up until the temperature of the fixing roller rises to the fixing temperature. Since the rotation speed of the fixing roller and the pressure roller is rotated at a warming-up rotation speed that is a predetermined speed lower than the rotation speed at the time of fixing, and thereafter, the rotation speed of the fixing roller and the pressure roller is rotated at the fixing speed until a predetermined time elapses. With a simple configuration, the unevenness of the temperature distribution on the surface of the fixing roller is suppressed, and the surface temperature of the fixing roller is quickly raised to the fixing temperature to start up. Latency can be shortened when Ri, to reduce power consumption it is possible to reduce operational costs, the fixing unevenness is prevented, it is possible to inexpensively improve the image quality.

In the image fixing method according to the present invention, the fixing roller heated to a predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are rotationally driven at a predetermined fixing rotation speed. An image fixing method for fixing the toner image to the transfer paper while conveying the transfer paper on which the toner image is transferred while being held between the fixing roller and the pressure roller which are driven to rotate, wherein the fixing roller During warm-up until the temperature of the fixing roller rises to the fixing temperature, the rotation speeds of the fixing roller and the pressure roller are changed until the rotation speed of the fixing roller and the pressure roller reaches a predetermined rotation speed. The motor is rotated at a warming-up rotation speed that is a predetermined speed lower than the fixing rotation speed, and the rotation speeds of the fixing roller and the pressure roller reach the predetermined rotation speed. Then, by rotating the rotational speed of the fixing roller and the pressure roller in the fixing during rotation speeds it has achieved the above objects.

According to the above construction, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are driven to rotate at the predetermined fixing rotation speed to transfer the toner image. When the toner image is fixed on the transfer paper while being conveyed while being held between the rotating transfer roller and the pressure roller by the fixing roller and the pressure roller, at the time of warming-up until the temperature of the fixing roller rises to the fixing temperature, the fixing roller The rotation speed of the fixing roller and the pressure roller is rotated at a warming-up rotation speed that is a predetermined speed lower than the rotation speed at the time of fixing until the rotation speed of the fixing roller reaches a predetermined rotation speed, and thereafter, the rotation driving at the fixing speed is performed. As a result, the surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution on the surface of the fixing roller. Can be shortened, it is possible to reduce operational costs by reducing power consumption,
Fixing unevenness can be prevented, and image quality can be improved.

In each of the above cases, for example, in the image fixing method, the rotational speed of the fixing roller and the pressing roller is changed from the rotational speed at the time of warm-up to the rotational speed at the time of fixing. When letting
A predetermined number of rotation speeds between the warming-up rotation speed and the fixing rotation speed may be changed by switching stepwise or may be changed continuously.

According to the above configuration, when changing the rotation speed of the fixing roller and the pressure roller from the rotation speed at the time of warming-up to the rotation speed at the time of fixing, a predetermined number of rotation speeds between the rotation speed at the time of warming-up and the rotation speed at the time of fixing. Is changed by changing stepwise or continuously, so that the rotation speed of the fixing roller can be smoothly changed to suppress the occurrence of vibration due to the rapid change of the rotation speed, and The waiting time can be shortened, the power consumption can be reduced, and the operating cost can be reduced. In addition, the image quality can be improved while preventing the uneven fixing and suppressing the vibration.

Further, for example, in the fixing roller, the heat generating member may be disposed in a layered manner near a surface of the fixing roller.

According to the above configuration, since the heat generating member is used as the fixing roller and disposed in a layered manner near the surface of the fixing roller, the surface of the fixing roller is more quickly raised to the fixing temperature, The waiting time at startup can be further reduced, the power consumption can be further reduced, the operation cost can be further reduced, and the image quality can be improved inexpensively by preventing the fixing unevenness. it can.

[0046]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 4 show a first embodiment of an image fixing apparatus and an image fixing method according to the present invention. In this embodiment, the fixing roller is lower than the fixing temperature from the start of warm-up. The motor is rotated at a warming-up rotation speed lower than the fixing rotation speed until the rotation switching temperature is reached, and corresponds to claims 1 and 6.

The present embodiment is applied to a fixing unit of an image recording apparatus such as an electrophotographic facsimile apparatus, a printer, and a copying apparatus.

FIG. 1 is a schematic sectional front view of an image recording apparatus 1 to which an image fixing apparatus and an image fixing method according to a first embodiment of the present invention are applied.

Referring to FIG. 1, an image recording apparatus 1 includes a main body 2 in which a recording section 3, a fixing section 4, a sheet feeding section 5, and the like are housed.

The recording section 3 has a charging section 11, an optical writing section 12, a developing section 13, a transfer section 14, a cleaning section 15, a charge removing section 16 and the like arranged around a photoreceptor 10. The embedding unit 12 emits a laser beam modulated with image data from a laser diode (not shown) to a polygon mirror 18 that is driven to rotate by a polygon motor 17, scans the polygon mirror 18 in the main scanning direction, and
Irradiates the surface of the photoreceptor 10 through

The paper supply unit 5 is provided with a plurality of recording papers (transfer papers) 2.
0, a sheet feeding roller 22, a pair of registration rollers 23, and the like.
The recording paper 20 is separated one by one by a paper feed roller 22 and sent to a registration roller pair 23. The resist roller pair 23 adjusts the timing of the recording paper 20 sent out by the paper feed roller 22 and then adjusts the timing of the photosensitive drum 10.
And between the transfer unit 14. A transport roller 24 is provided between the transfer unit 14 and the photoconductor 10, and the transport roller 24 transfers the recording paper 20 sent from the registration roller pair 23 between the transfer unit 14 and the photoconductor 10. Transport to

The recording section 3 uniformly charges the photoconductor 10 with the charging section 11 while rotating the photoconductor 10 at a predetermined rotation speed, and modulates the laser beam with image data by the optical writing section 12. Is irradiated onto the photoconductor 10 to form an electrostatic latent image on the photoconductor 10. The recording unit 3 supplies the toner to the photoreceptor 10 on which the electrostatic latent image is formed by the developing unit 13 and develops the toner.
The transfer unit 14 transfers the toner image formed on the surface of the photoconductor 10 onto the recording paper 20 that has been conveyed between the transfer unit 14 and the photoconductor 10 from the paper supply unit 5.

The recording unit 3 further rotates the photoconductor 10 on which the transfer is completed, removes the residual toner remaining on the photoconductor 10 by the cleaning unit 15, removes the charge of the photoconductor 10 by the charge removing unit 16, and again Then, the photoreceptor 10 is uniformly charged by the charging unit 11, and the same image recording operation as described above is performed.

The recording paper 20 on which the toner image has been transferred by the recording unit 3 is conveyed to a fixing unit 4, and after the toner image on the recording paper 20 is fixed by the fixing unit 4, the main body casing 2 (not shown) The paper is discharged onto an external paper discharge tray.

The fixing unit (image fixing device) 4 includes an upper case 3
0, the fixing roller 31 is housed in the lower case 32.
A pressure roller 33 is housed therein. Fixing roller 31
Is a heating member 3 such as a halogen lamp as shown in FIG.
4 is heated to a predetermined fixing temperature Tst by the heat generating member 34. A temperature detection sensor 35 such as a thermistor is provided near the surface of the fixing roller 31, and the temperature detection sensor (temperature detecting means) 35 detects the surface temperature of the fixing roller 31. The pressing roller 33 is urged toward the fixing roller 31 by a pressing member (not shown), for example, a coil spring or the like, and is pressed against the fixing roller 31 with a predetermined pressure. In FIG. 2, Tg
Indicates a toner image transferred onto the recording paper 20.

As shown in FIG. 3, the image recording apparatus 1 includes a fixing roller temperature control unit 40, a rotation speed control unit 41, a motor driver 42, a fixing roller driving motor 43, and the like.

The fixing roller driving motor 43 rotates the fixing roller 31 via gears and the like. When the fixing roller 31 is driven to rotate by the fixing roller driving motor 43, the pressing roller pressed by the fixing roller 31 33 is driven to rotate.

The fixing roller driving motor 43 is driven to rotate by a rotation speed control unit 41 via a motor driver 42, and its rotation speed is controlled. The rotation speed control unit 41 detects the temperature detected by the temperature detection sensor 35. The surface temperature of the fixing roller 31 is input. The rotation speed control unit 41
At the time of fixing the toner image on the recording paper 20 to the recording paper 20 by passing the recording paper 20 in the fixing unit 4, the motor driver 42 is controlled to rotate the fixing roller 31 via the fixing roller driving motor 43. The speed is rotated at a preset fixing rotation speed Vu, and at the time of warming-up, a preset rotation switching temperature Tsn in which the surface temperature of the fixing roller 31 detected by the temperature detection sensor 35 is lower than the fixing temperature Tst by a predetermined temperature. Until the rotation speed of the fixing roller 31 is reached, the rotation speed of the fixing roller 31 is controlled to a predetermined rotation speed Vw at the time of warming-up, which is lower by a predetermined speed than the rotation speed Vu at the time of fixing. Control, and thereafter, the fixing roller 31
Is controlled to the fixing rotation speed Vu. Therefore, the fixing roller driving motor 43 and the motor driver 42 function as rotation driving means for driving the fixing roller 31 and the pressure roller 33 to rotate.
Functions as a rotation speed control unit that controls the rotation speed of the fixing roller 31 and the pressure roller 33.

The fixing roller temperature control section 40 is connected to a heat generating member 34 incorporated in the fixing roller 31, and the fixing roller temperature control section 40 has a surface temperature of the fixing roller 31 detected by the temperature detection sensor 35. Is entered,
The fixing roller temperature controller 40 controls the power supply to the heat generating member 34 based on the detection result of the temperature detection sensor 35,
The surface temperature of the fixing roller 31 is controlled to a predetermined fixing temperature Tst.

Next, the operation of the present embodiment will be described. The image recording apparatus 1 changes the rotation speed of the fixing roller 31 to the fixing rotation speed Vu until the temperature of the fixing roller 31 reaches the rotation switching temperature Tsn lower than the fixing temperature Tst at the time of warming up, that is, at the start of the temperature rise. The feature is that the speed is controlled to the warming-up rotation speed Vw which is slower than that.

That is, when the power of the image recording apparatus 1 is turned on or the start key for starting recording is turned on during standby, the image recording apparatus 1 starts warming up.
When the start of the temperature rise of the image recording apparatus 1 is instructed, first, the power supply to the heat generating member 34 is started by the fixing roller temperature control unit 40 to start the heating of the fixing roller 31 and the rotation speed control unit 41 The fixing roller driving motor 43 is rotated via the motor driver 42, and the fixing roller 31 is driven to rotate at the warming-up rotation speed Vw (0 <Vw <Vu) lower than the rotation speed Vu during fixing by a predetermined speed. Due to the rotation of the fixing roller 31, the pressure roller 33 pressed by the fixing roller 31 is driven to rotate, and the fixing roller 31 and the pressure roller 33 rotate together.

The image recording apparatus 1 heats the fixing roller 31 by the heat generating member 34 while rotating the fixing roller 31 and the pressure roller 33 at the rotation speed Vw at the time of warming-up in the above state. Is detected by the temperature detection sensor 35.

The rotation speed control unit 41 is provided with the temperature detection sensor 3
5 is the fixing temperature Ts.
It is checked whether the rotation switching temperature Tsn lower than t has been reached, and the fixing roller 31 is driven to rotate at the warm-up rotation speed Vw until the surface temperature of the fixing roller 31 reaches the rotation switching temperature Tsn.

When the surface temperature of the fixing roller 31 detected by the temperature detection sensor 35 reaches the rotation switching temperature Tsn, the rotation speed control unit 41 controls the motor driver 42 to perform the fixing through the fixing roller driving motor 43. Roller 3
1 is driven to rotate at the fixing rotation speed Vu. in this case,
The rotation speed Vw at the time of warming-up is 1/10 (1/10) of the rotation speed Vu at the time of fixing (Vw = 1/10).
Vu).

That is, as shown in FIG. 4, the fixing roller 31 is turned on when the power of the image recording apparatus 1 is turned on or when a start key for starting recording is turned on.
When the surface temperature (warming-up start temperature) of the fixing roller 31 is set to To, the rotation speed control unit 41 controls the fixing roller 31 to rotate the fixing rotation speed Vu until the surface temperature of the fixing roller 31 reaches the rotation switching temperature Tsn. When the surface temperature of the fixing roller 31 reaches a rotation switching temperature Tsn lower than the fixing temperature Tst, the fixing roller 31 is rotated from the warming-up rotation speed Vw to the fixing rotation speed Vw. Vu
And drive it to rotate.

Therefore, as shown in FIG. 4, the surface of the fixing roller 31 is rotated at the warming-up rotation speed Vw, which is a slow rotation speed, up to the rotation switching temperature Tsn. When the rotation switching temperature Tsn is lower than the fixing temperature Tst, the fixing is stopped. Since the roller 31 is rotated while being switched to the fast fixing rotation speed Vu, the unevenness in the temperature distribution is completely eliminated, and the fixing temperature Ts quickly rises appropriately while suppressing overshoot.

As a result, the surface temperature of the fixing roller 31 is
The fixing temperature Tst can be raised in a short time without unevenness while suppressing overshoot, and the image quality can be improved while shortening the waiting time until the start of recording.

FIGS. 5 to 7 are views showing a second embodiment of the image fixing apparatus and the image fixing method of the present invention. In this embodiment, the fixing roller is changed in accordance with the time from the start of warming up. Claim 2 wherein the rotational speed is changed.
And claim 7.

This embodiment is applied to the same image recording apparatus as that of the first embodiment, and in the description of this embodiment, the same as that of the first embodiment will be described. Constituent parts are denoted by the same reference numerals and description thereof is omitted.
Description will be made by using the reference numerals used in the description of the first embodiment as they are.

FIG. 5 shows an image recording apparatus 60 to which the second embodiment of the image fixing apparatus and the image fixing method of the present invention is applied.
The image recording apparatus 60 includes a heating member 34 for heating the fixing roller 31 similar to that of the first embodiment, a temperature detection sensor 35 for detecting the surface temperature of the fixing roller 31, and a fixing device. It includes a roller temperature control unit 40, a fixing roller driving motor 43, a motor driver 42, and the like, and also includes a timer 61 and a rotation speed control unit 62.

The timer (time measuring means) 61 includes, for example, an oscillation circuit and a frequency dividing circuit, generates various clocks for measuring the current time and setting various timings, and outputs the generated clocks to the rotation speed control unit 62. In particular, the timer 61 measures the elapsed time A from when the power of the image recording apparatus 60 is turned on or when the recording start instruction is issued, and outputs the time to the rotation speed control unit 62.

Rotation speed control section (rotation speed control means) 62
Controls the rotation of the fixing roller driving motor 43 by controlling the motor driver 42, rotates the fixing roller 31 by the fixing roller driving motor 43, and controls the rotation speed of the fixing roller 31.

That is, at the time of fixing, the rotation speed control unit 62 controls the motor driver 42 to rotate the rotation speed of the fixing roller 31 at the fixing rotation speed Vu via the fixing roller driving motor 43, thereby warming up. At this time, the elapsed time A input from the timer 61 is compared with a predetermined rotation switching time Asn set before the rotation speed of the fixing roller 31 is switched, and the elapsed time A reaches the rotation switching time Asn. During this period, the motor driver 42 is controlled to reduce the rotation speed of the fixing roller 31 via the fixing roller driving motor 43 by a predetermined warming-up rotation speed V that is lower than the fixing rotation speed Vu by a predetermined speed.
w, and thereafter, the rotation speed of the fixing roller 31 is controlled to the fixing rotation speed Vu.

Next, the operation of the present embodiment will be described. The image recording apparatus 60 according to the present embodiment rotates the fixing roller 31 at the warming-up rotation speed Vw lower than the fixing-time rotation speed Vu until the elapsed time A from the start of the warming-up reaches the rotation switching time Asn. And
After that, it is characterized in that it is driven to rotate at the fixing rotation speed Vu.

That is, as shown in FIG. 6, when the power of the image recording apparatus 60 is turned on or the start key for starting recording is turned on (step S1), the temperature of the image recording apparatus 1 is started to rise. First, the fixing roller temperature controller 4
0, energization of the heat generating member 34 is started, heating of the fixing roller 31 is started, and the fixing roller driving motor 43 is rotationally driven by the rotation speed control unit 62 via the motor driver 42, so that the fixing roller 31 is driven. The rotation is performed at the warming-up rotation speed Vw that is lower than the fixing rotation speed Vu by a predetermined speed (step S2). Due to the rotation of the fixing roller 31, the pressure roller 33 pressed by the fixing roller 31 is driven to rotate, and the fixing roller 31 and the pressure roller 33 rotate together.

At this time, the timer 61 starts counting the elapsed time A, and outputs the counted elapsed time A to the rotation speed control unit 62. The rotation speed control unit 62 outputs the elapsed time A input from the timer 61. It is checked whether A exceeds a preset rotation switching time Asn, for example, 30 seconds (step S3).

If the elapsed time A does not exceed the rotation switching time Asn in step S3, the rotation speed control section 62 returns to step S2, and drives the fixing roller 31 to rotate at the warming-up rotation speed Vw (step S2). It is checked again whether the elapsed time A has exceeded the rotation switching time Asn (step S3).

The above processing is sequentially performed, and in step S3,
When the elapsed time A exceeds the rotation switching time Asn, the rotation speed control unit 62 drives the fixing roller driving motor 43 to rotate via the motor driver 42 to rotate the fixing roller 31 from the warming-up rotation speed Vw to the fixing rotation speed. V
The rotation is switched to u (Step S4), and it is determined from the detection result of the temperature detection sensor 35 whether the surface temperature T of the fixing roller 31 has reached the fixing temperature Tst (Step S5).

In step S5, the temperature T of the fixing roller 31
Is not at the fixing temperature Tst, the rotation speed control unit 62 rotates the fixing roller 31 at the fixing rotation speed Vu (step S4), and when the temperature of the fixing roller 31 becomes the fixing temperature Tst at step S5, The startup processing ends.

That is, as shown in FIG. 7, the image recording apparatus 60 has a surface temperature of the fixing roller 31 when the power of the image recording apparatus 60 is turned on or when a start key for starting recording is turned on. Temperature) to To
The rotation speed control unit 62 keeps the fixing roller 31 rotating the fixing speed 31 by a predetermined speed lower than the fixing rotation speed Vu until the elapsed time A after the power is turned on reaches the rotation switching time Asn. Vw rotation drive,
When the elapsed time A exceeds the rotation switching time Asn, the fixing roller 31 is rotated and driven from the warming-up rotation speed Vw to the fixing rotation speed Vu.

Accordingly, as shown in FIG. 7, the surface of the fixing roller 31 is fixed until the elapsed time A from the start of the warm-up reaches the rotation switching time Asn.
Since 1 is rotated at the warming-up rotation speed Vw, which is a low rotation speed, the unevenness of the temperature distribution is eliminated,
The temperature quickly rises, and the elapsed time A is equal to the rotation switching time Asn.
After that, since the fixing roller 31 is rotated by switching to the fast fixing rotation speed Vu, the unevenness of the temperature distribution is completely eliminated, and the fixing roller 31 is quickly moved to the fixing temperature Tst while suppressing overshoot. To rise.

As a result, the surface temperature of the fixing roller 31 becomes
It is possible to raise the fixing temperature Tst with a simple structure, in a short time, without suppressing overshoot and without unevenness, to improve the image quality at low cost while reducing the waiting time until the start of recording. Can be.

FIGS. 8 to 10 are views showing a third embodiment of the image fixing apparatus and the image fixing method according to the present invention. This changes the rotation speed of the fixing roller, and corresponds to claims 3 and 8.

Note that this embodiment is applied to the same image recording apparatus as that of the first embodiment, and in the description of this embodiment, the same image recording apparatus as that of the first embodiment will be described. Constituent parts are denoted by the same reference numerals and description thereof is omitted.
Description will be made by using the reference numerals used in the description of the first embodiment as they are.

FIG. 8 shows an image recording apparatus 70 to which an image fixing apparatus and an image fixing method according to the second embodiment of the present invention are applied.
The image recording apparatus 70 includes a heating member 34 for heating the fixing roller 31 similar to that of the first embodiment, a temperature detection sensor 35 for detecting the surface temperature of the fixing roller 31, The apparatus includes a roller temperature control unit 40, a fixing roller driving motor 43, a motor driver 42, and the like, and also includes a rotation speed measurement unit 71 and a rotation speed control unit 72.

The rotation speed measuring section (rotation speed detecting means) 71
For example, it is configured by an encoder or the like and is disposed near the fixing roller 31, detects the rotation speed of the fixing roller 31, and outputs the detected rotation speed to the rotation speed control unit 72.

Rotation speed control section (rotation speed control means) 72
Controls the rotation of the fixing roller driving motor 43 by controlling the motor driver 42, rotates the fixing roller 31 by the fixing roller driving motor 43, and controls the rotation speed of the fixing roller 31.

That is, at the time of fixing, the rotation speed control unit 72 controls the motor driver 42 to rotate the rotation speed of the fixing roller 31 at the fixing rotation speed Vu via the fixing roller driving motor 43, thereby warming up. At this time, the rotation speed N of the fixing roller 31 input from the rotation speed measurement unit 71 is compared with a predetermined rotation switching rotation speed Nsn set in advance as a rotation speed for switching the rotation speed of the fixing roller 31, and Until the rotation speed N reaches the rotation switching rotation speed Nsn, the motor driver 42 is controlled to increase the rotation speed of the fixing roller 31 via the fixing roller driving motor 43 by a predetermined speed from the fixing rotation speed Vu. The rotation speed at the time of the predetermined warm-up is controlled to be slow, and thereafter, the rotation speed of the fixing roller 31 is changed to the rotation speed at the time of the fixing. To control to.

Next, the operation of the present embodiment will be described. The image recording apparatus 70 of the present embodiment fixes at the warming-up rotation speed Vw lower than the fixing-time rotation speed Vu until the rotation speed N of the fixing roller 31 reaches the rotation switching rotation speed Nsn from the start of warming-up. Roller 3
1 is driven to rotate and then driven to rotate at the fixing rotation speed Vu.

That is, as shown in FIG. 9, when the power of the image recording apparatus 70 is turned on or the start key for starting recording is turned on (step P1), the temperature of the image recording apparatus 1 is started to rise. First, the fixing roller temperature controller 4
0, energization of the heat generating member 34 is started, heating of the fixing roller 31 is started, and the fixing roller driving motor 43 is rotationally driven by the rotation speed control unit 72 via the motor driver 42, so that the fixing roller 31 is driven. The motor is driven to rotate at the warming-up rotation speed Vw which is lower by a predetermined speed than the fixing rotation speed Vu (step P2). Due to the rotation of the fixing roller 31, the pressure roller 33 pressed by the fixing roller 31 is driven to rotate, and the fixing roller 31 and the pressure roller 33 rotate together.

At this time, the rotation speed measurement unit 71 starts measuring the rotation speed N of the fixing roller 31 after the start of rotation, outputs the measured rotation speed N to the rotation speed control unit 72, and outputs the measured rotation speed N to the rotation speed control unit 72. 72 checks whether the rotation speed N input from the rotation speed measurement unit 71 exceeds a preset rotation switching rotation speed Nsn, for example, 40 rotations (step P).
3).

If the rotation speed N of the fixing roller 31 has not exceeded the rotation switching speed Nsn in step P3, the rotation speed control unit 72 returns to step P2 and
Is rotated at the warming-up rotation speed Vw (step P2), and it is again checked whether the rotation speed N of the fixing roller 31 exceeds the rotation switching rotation speed Nsn (step P2).
3).

The above processing is sequentially performed, and in step P3,
When the rotation speed N of the fixing roller 31 exceeds the rotation switching rotation speed Nsn, the rotation speed control unit 72 rotates the fixing roller driving motor 43 via the motor driver 42 to rotate the fixing roller 31 at the warming-up rotation speed Vw. Is switched to the fixing rotation speed Vu to rotate (step P4), and the surface temperature T of the fixing roller 31 becomes the fixing temperature Ts.
It is determined from the detection result of the temperature detection sensor 35 whether or not t has been reached (step P5).

In Step P5, the temperature T of the fixing roller 31
Is not at the fixing temperature Tst, the rotation speed control unit 72 rotates the fixing roller 31 at the fixing rotation speed Vu (step S4), and when the temperature of the fixing roller 31 becomes the fixing temperature Tst at step P5, The startup processing ends.

That is, as shown in FIG. 10, the surface temperature of the fixing roller 31 when the power of the image recording apparatus 70 is turned on or the start key for starting recording is turned on (as shown in FIG. 10). Temperature) to T
When the rotation speed is set to o, the rotation speed control unit 72 keeps the fixing roller 31 rotating at the fixing rotation speed Vu until the rotation speed N of the fixing roller 31 reaches the rotation switching rotation speed Nsn after the power is turned on.
The rotation speed Vw at the time of warm-up that is lower than the predetermined speed
When the rotation speed N of the fixing roller 31 exceeds the rotation switching rotation speed Nsn, the fixing roller 31 is switched from the warming-up rotation speed Vw to the fixing rotation speed Vu and driven to rotate.

Therefore, as shown in FIG. 10, the surface of the fixing roller 31 is warmed up at a low rotational speed from the start of the warming-up until the rotation speed N of the fixing roller 31 reaches the rotation switching speed Nsn. Since the rotation is performed at the hour rotation speed Vw, the temperature rises quickly while eliminating the unevenness of the temperature distribution, and the fixing roller 31
When the rotation speed N reaches the rotation switching rotation speed Nsn, thereafter, the fixing roller 31 is switched to the fast fixing rotation speed Vu and rotated, so that the unevenness of the temperature distribution is completely eliminated and the overshoot is performed. , And quickly rises appropriately to the fixing temperature Tst.

As a result, the surface temperature of the fixing roller 31 becomes
The fixing temperature Tst can be raised in a short time without unevenness while suppressing overshoot, and the image quality can be improved while shortening the waiting time until the start of recording.

In each of the above embodiments, the rotation speed Vw during warming-up is changed to the rotation speed Vu during fixing.
The switching of the rotation speed of the fixing roller 31 from the warming-up rotation speed Vw to the fixing rotation speed Vu is performed at the same time as the warming-up rotation speed Vw.
One or more switching speeds having a speed between the warming-up rotation speed Vw and the fixing rotation speed Vu are provided between the warming-up rotation speed Vw and the fixing rotation speed Vu. May be switched stepwise during a predetermined time, or may be continuously changed from the warming-up rotation speed Vw to the fixing rotation speed Vu for a predetermined time. This fixing roller 3
As a method of changing the rotation speed of the fixing roller in a stepwise or continuous manner, the rotation speed of the fixing roller drive motor 43 may be controlled or performed by using a drive transmission mechanism such as a gear or a belt. You may.

In each of the above embodiments, the rotation speed of the fixing roller drive motor 43 is actually controlled to increase the rotation speed of the fixing roller 31 during the warm-up rotation speed Vw.
And the fixing rotational speed Vu are set in five steps, and the rotational speed during warming-up Vw is gradually changed from the rotational speed Vw during fixing to the rotational speed Vu during warming-up. It was possible to reduce the occurrence of the impact vibration that had occurred when changing all at once.

In this manner, the rotation speed of the fixing roller 31 can be smoothly switched from the rotation speed Vw at the time of warm-up to the rotation speed Vu at the time of fixing, and the occurrence of vibration and the like can be suppressed.

In each of the above embodiments, the rotation speed of the fixing roller drive motor 43 is controlled via the motor driver 42 to control the rotation speed of the fixing roller 31. The control of the rotation speed is not limited to the one that changes the rotation speed of the fixing roller driving motor 43.
The rotation speed of the fixing roller 31 may be controlled by switching the gear mechanism while keeping the rotation speed of the fixing roller 31 constant.

For example, as shown in FIGS. 11 and 12,
As the gear mechanism 80, a high-speed gear 81 and a low-speed gear 82 are rotatably attached to both ends of a substantially U-shaped clutch arm 83, and mesh with the high-speed gear 81 and the low-speed gear 82 at the center of the clutch arm 83. And a small-diameter gear 82a meshing with the transmission gear 84 and a large-diameter gear 82 fixedly connected to the small-diameter gear 82a and rotating with the rotation of the small-diameter gear 82a.
b) is used. A motor gear 85 fixed to the rotating shaft of the fixing roller driving motor 43 meshes with the transmission gear 84, and a driving gear 86 is fixed to the rotating shaft of the fixing roller 31.

In the gear mechanism 80, the clutch arm 83 swings around the central portion where the transmission gear 84 is attached, and the large-diameter gear 82b of the high-speed gear 81 and the low-speed gear 82 is selectively meshed with the drive gear 86. The driving gear 86 is rotated by the large-diameter gear 82b of the high-speed gear 81 or the low-speed gear 82 via the transmission gear 84 so that the fixing roller 31 is rotated.

Therefore, when the rotation speed of the fixing roller drive motor 43 is kept constant and the rotation speed of the fixing roller 31 is driven to rotate at the warming-up rotation speed Vw, the crack arm 83 is swung and the low speed gear 82 is rotated.
When the large-diameter gear 82b is meshed with the drive gear 86, and the rotation speed of the fixing roller 31 is driven to rotate at the fixing rotation speed Vu, the clutch arm 83 is swung so that the high-speed gear 81 is meshed with the drive gear 86. Combine.

In this way, the rotation speed of the fixing roller 31 can be switched and controlled without changing the rotation speed of the fixing roller driving motor 43.

Further, in each of the above-described embodiments, as shown in FIG. 2, a general fixing roller in which a heat generating member 34 is built in the center of the hollow cylindrical fixing roller 31 as shown in FIG. However, the fixing roller is not limited to the one in which the heat generating member 34 is built in the center of the fixing roller. For example, as shown in FIG. 13, a heat generating member is disposed near the surface. May be used. That is, as shown in FIG.
Reference numeral 0 may be such that a heat-generating member 92 is formed in a plane or a line on the surface of a cylindrical base 91, and a heat-resistant resin layer 93 is formed on the surface of the base 91 so as to cover the heat-generating member 92. The heating member 92 is made of, for example,
Ceramic heating element, Nichrome, Ta ₂ N , RuO ₂ , A
It can be formed on the surface of the base 91 by thermal spraying, coating, printing, or the like, using a heating resistor such as g / Pd. The base 91 may be made of glass, ceramics, resin, or a metal such as Al or SUS. If a metal is used, the base 91 may be made of SiO ₂ , polyimide, or the like in order to electrically insulate the heating member 92. After the insulating layer made of the above resin material or the like is formed on the surface of the base 91, the heating member 92 is formed on the insulating layer. The heat-resistant resin layer 93 is
It has the function of improving the releasability from the toner, preventing the heat generating member 92 from being damaged by the contact of the heat generating member 92 with another member, and further, electrically insulating the heat generating member 92. Teflon or the like can be used as the material.

As described above, when the fixing roller 90 provided with the heating member 92 near the surface is used, heat is generated near the surface of the fixing roller 90, so that the heating efficiency can be improved, and the fixing roller 90 is fixed. The startup time required for heating to the temperature Tst can be greatly reduced.

In this case, it is effective to reduce the heat capacity of the base 91 in order to further shorten the time for starting the fixing roller 90.

However, when the heat capacity of the base 91 is reduced, the fixing roller 90 can be quickly heated to the fixing temperature Tst. However, the heat easily escapes from the fixing roller 90, and the fixing roller 90 and the pressing roller 33 A phenomenon occurs in which the temperature is reduced only in the pressure contact portion of.

Therefore, when the fixing roller 9 is
When 0 is stopped, the temperature drop of the pressure contact portion with the pressure roller 33 is larger than that of other portions, and the temperature distribution of the fixing roller 90 is greatly different depending on the place, and the possibility of occurrence of fixing unevenness is high. Become.

However, as in the above embodiments, at the time of warming-up, the fixing roller 9 is moved until a predetermined timing.
0 and the rotation speed V when the pressure roller 33 is warmed up.
When the fixing roller 90 is rotated at the fixing rotation speed Vu, even if the fixing roller 90 has a small heat capacity, the surface temperature of the fixing roller 90 can be appropriately adjusted as described above. The image quality can be improved without causing fixing unevenness, and the temperature of the fixing roller 90 can be quickly reduced to the fixing temperature T.
The waiting time can be further shortened by increasing to st. <Experimental Example> The following experiment was conducted using the fixing roller 90 as the fixing roller 31 of the image recording apparatus 1 according to the first embodiment.

The configuration of the fixing roller 90 is the same as that shown in FIG. 13, and the diameter of the heat roller 90 is 30 m.
m, the thickness of the substrate 91 was 1 mm, and a liquid crystal polymer was used as the material of the substrate 91.

The heating member 92 of the fixing roller 90
0 W of power is supplied, and as in the image recording apparatus 1 according to the first embodiment, when the warming-up is performed, the surface temperature of the fixing roller 90 is reduced to the rotation switching temperature Tsn lower than the fixing temperature Tst. 90 was rotated at the rotation speed Vw at the time of warming-up, and then rotated at the rotation speed Vu at the time of fixing.

As a result of the experiment, as shown by the line T1 in FIG. 14, the surface temperature of the fixing roller 90 could be quickly increased to the fixing temperature Tst while suppressing the temperature distribution. <Comparative Experiment 1> Using the fixing roller 90 as the fixing roller 31 of the image recording apparatus 1 of the first embodiment,
The following comparative experiment was performed.

The configuration of the fixing roller 90 used in the comparative experiment is the configuration shown in FIG. 13. The diameter of the fixing roller 90 is 30 mm, the thickness of the base 91 is 1.5 mm, and
Al was used as the material of No. 1.

The heating member 92 of the fixing roller 90
0W power is supplied, the rotation of the fixing roller 90 is stopped until the surface temperature of the fixing roller 90 rises to the fixing temperature Tst, and the surface temperature of the fixing roller 90 is reduced to the fixing temperature Tst.
st, the fixing roller 90 is rotated at fixing speed V
Rotated with u.

As a result of this comparative experiment, as shown by the line T2 in FIG. 14, the surface temperature of the fixing roller 90 showed large temperature unevenness, and when the temperature reached the fixing temperature Tst, a large overshoot occurred. .

From this comparative experiment, it can be seen that rotating the fixing roller 90 at the warming-up rotation speed Vw lower than the fixing rotation speed Vu can quickly reduce the fixing temperature Tst while suppressing the temperature distribution of the surface temperature of the fixing roller 90. Has been found to be effective in raising. <Comparative Experiment 2> Image Recording Apparatus 1 of First Embodiment
The following comparative experiment was performed using. The configuration of the fixing roller 31 used in this comparative experiment is the same as the configuration shown in FIG. 2, and a halogen lamp is used as the heat generating member 34 of the fixing roller 31.

While the fixing roller 31 is heated by the heat generating member 34, the surface temperature of the fixing roller 31 is lower than the fixing temperature Tst at the time of warming-up, as in the image recording apparatus 1 of the first embodiment. Rotation switching temperature Tsn
Until then, the fixing roller 31 was rotated at the rotation speed Vw during warm-up, and thereafter rotated at the rotation speed Vu during fixing.

As a result of the experiment, as shown by the line T3 in FIG. 14, the surface temperature of the fixing roller 31 rises to the fixing temperature Tst slightly more slowly than in the above-mentioned experimental example while suppressing the temperature distribution. I was able to.

As a result of this comparison experiment, it was found that rotating the fixing roller 31 at the warming-up rotation speed Vw, which is lower than the rotation speed Vu at the time of fixing, can quickly reduce the fixing temperature while suppressing the temperature distribution of the surface temperature of the fixing roller 31. It was found to be effective in increasing to Tst. In addition, the surface temperature of the fixing roller 90 having the heating member 92 formed near the surface is more quickly lowered to the fixing temperature Tst than the fixing roller 31 having the halogen heater, which is the heating member 34, built in the center as the fixing roller. It was found to rise.

The invention made by the inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in each of the above embodiments, the fixing roller 31 is driven to rotate by the fixing roller driving motor 43, and the pressure roller 33 is rotated by the rotation of the fixing roller 31. The rotation of the pressure roller 33 is not limited to the above method. For example, the rotation of the pressure roller 33 by a motor and the rotation of the fixing roller 31 by the rotation of the pressure roller 33 may be performed. Alternatively, the fixing roller 31 and the pressing roller 33 may be rotationally driven by the same motor via a gear mechanism.

[0125]

According to the image fixing apparatus of the first aspect of the present invention, the fixing roller heated to a predetermined fixing temperature by the heating member and the pressing roller pressed against the fixing roller are rotated at a predetermined fixing speed. When the toner image is fixed on the transfer paper while the transfer paper on which the toner image has been transferred is conveyed while being held between the fixing roller and the pressure roller which are rotationally driven, the temperature of the fixing roller is fixed at the fixing temperature. During the warm-up period until the temperature rises, until the surface temperature of the fixing roller reaches a rotation switching temperature lower by a predetermined temperature than the fixing temperature,
Since the rotation speed of the fixing roller and the pressure roller is rotated by a predetermined speed lower than the rotation speed at the time of fixing by the rotation speed control means and at the rotation speed at the time of warming-up, and thereafter, the rotation speed at the fixing speed is increased. The surface temperature of the fixing roller can be quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution of the above, the waiting time at the time of startup can be reduced, the power consumption can be reduced, and the operating cost can be reduced. In addition, the image quality can be improved by preventing fixing unevenness.

According to the image fixing device of the present invention, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are rotated at the predetermined fixing rotation speed. The temperature of the fixing roller rises to the fixing temperature when the toner image is fixed on the transfer paper while the transfer paper on which the toner image has been transferred is nipped and conveyed by the rotationally driven fixing roller and the pressure roller. During the warm-up period until the predetermined time elapses from the start of the warm-up period, the rotation speed control unit rotates the rotation speeds of the fixing roller and the pressure roller at the warm-up rotation speed that is a predetermined speed lower than the fixing rotation speed. After that, since it is driven to rotate at the fixing speed, it has a simple configuration and quickly suppresses uneven temperature distribution on the surface of the fixing roller, By raising the surface temperature of the application roller to the fixing temperature, the waiting time at startup can be shortened, the power consumption can be reduced, and the operating cost can be reduced. Image quality can be improved.

According to the image fixing apparatus of the present invention, the fixing roller heated to the predetermined fixing temperature by the heat generating member and the pressure roller pressed against the fixing roller are rotated at the predetermined fixing rotation speed. The temperature of the fixing roller rises to the fixing temperature when the toner image is fixed on the transfer paper while the transfer paper on which the toner image has been transferred is nipped and conveyed by the rotationally driven fixing roller and the pressure roller. During the warm-up period, the rotation speed of the fixing roller and the pressing roller is reduced by a predetermined speed lower than the rotation speed during fixing until the rotation speed of the fixing roller reaches the predetermined rotation speed. The fixing roller is driven to rotate at a rotation speed and then at the fixing speed, so that the fixing roller surface temperature can be quickly reduced while suppressing the unevenness of the temperature distribution on the fixing roller surface. The was raised to the fixing temperature, it is possible to reduce the waiting time at the rising edge, it is possible to reduce operational costs by reducing power consumption,
Fixing unevenness can be prevented, and image quality can be improved.

According to the image fixing apparatus of the present invention, when changing the rotation speed of the fixing roller and the pressing roller from the rotation speed at the time of warming up to the rotation speed at the time of fixing, the rotation speed at the time of warming up and the rotation speed at the time of fixing are changed. A predetermined number of rotation speeds between are changed stepwise and changed,
Alternatively, since it is continuously changed, the rotation speed of the fixing roller can be smoothly changed to suppress the occurrence of vibration due to a rapid change in the rotation speed, and the waiting time at the time of startup can be reduced, The power consumption can be reduced to reduce the operation cost, and the image quality can be improved while preventing the fixing unevenness and suppressing the vibration.

According to the image fixing apparatus of the present invention, since the heat generating member is disposed in a layered form near the surface of the fixing roller as the fixing roller, the surface of the fixing roller can be moved more quickly. In addition, the fixing temperature can be increased to further reduce the waiting time at startup, further reduce power consumption, further reduce operating costs, prevent uneven fixing, and reduce costs. Image quality can be improved.

According to the image fixing method of the present invention, the fixing roller heated to the predetermined fixing temperature by the heating member and the pressure roller pressed against the fixing roller are rotated at the predetermined fixing rotation speed. The temperature of the fixing roller rises to the fixing temperature when the toner image is fixed on the transfer paper while the transfer paper on which the toner image has been transferred is nipped and conveyed by the rotationally driven fixing roller and the pressure roller. At the time of warming up until the fixing roller surface temperature reaches a rotation switching temperature that is a predetermined temperature lower than the fixing temperature,
The rotation speed of the fixing roller and the pressure roller is rotated at a warming-up rotation speed that is a predetermined speed lower than the rotation speed at the time of fixing, and thereafter, the rotation speed is driven at the fixing speed. While suppressing
By quickly raising the surface temperature of the fixing roller to the fixing temperature, the waiting time at the time of startup can be reduced, the power consumption can be reduced, and the operating cost can be reduced. Image quality can be improved.

According to the image fixing method of the present invention, the fixing roller heated to the predetermined fixing temperature by the heating member and the pressure roller pressed against the fixing roller are rotated at the predetermined fixing rotation speed. The temperature of the fixing roller rises to the fixing temperature when the toner image is fixed on the transfer paper while the transfer paper on which the toner image has been transferred is nipped and conveyed by the rotationally driven fixing roller and the pressure roller. During the warm-up period until the predetermined time elapses from the start of the warm-up, the rotation speeds of the fixing roller and the pressure roller are rotated at the warm-up rotation speed that is a predetermined speed lower than the rotation speed at the time of fixing, and thereafter, the fixing speed is increased. , Which quickly fixes the surface temperature of the fixing roller while suppressing unevenness in the temperature distribution on the surface of the fixing roller with a simple configuration. It is possible to reduce the waiting time at startup, reduce power consumption and reduce operating costs, and also prevent uneven fixing and improve image quality at low cost. it can.

According to the image fixing method of the present invention, the fixing roller heated to the predetermined fixing temperature by the heating member and the pressure roller pressed against the fixing roller are rotated at the predetermined fixing rotation speed. The temperature of the fixing roller rises to the fixing temperature when the toner image is fixed on the transfer paper while the transfer paper on which the toner image has been transferred is nipped and conveyed by the rotationally driven fixing roller and the pressure roller. During the warm-up period, the rotation speeds of the fixing roller and the pressure roller are rotated at the warm-up rotation speed that is lower than the rotation speed during the fixing until the rotation speed of the fixing roller reaches the predetermined rotation speed. Then, since it is driven to rotate at the fixing speed, the surface temperature of the fixing roller is quickly raised to the fixing temperature while suppressing the unevenness of the temperature distribution on the surface of the fixing roller. It is possible to shorten the waiting time of rising consumption with power can be reduced to reduce to operating costs, fixing unevenness is prevented, thereby improving the image quality.

According to the image fixing method of the ninth aspect, when the rotational speeds of the fixing roller and the pressure roller are changed from the warming-up rotational speed to the fixing rotational speed, the warming-up rotational speed and the fixing rotational speed are changed. A predetermined number of rotation speeds between are changed stepwise and changed,
Alternatively, since it is continuously changed, the rotation speed of the fixing roller can be smoothly changed to suppress the occurrence of vibration due to a rapid change in the rotation speed, and the waiting time at the time of startup can be reduced, The power consumption can be reduced to reduce the operation cost, and the image quality can be improved while preventing the fixing unevenness and suppressing the vibration.

According to the image fixing method of the tenth aspect, since the heat generating member is disposed in the form of a layer near the surface of the fixing roller as the fixing roller, the surface of the fixing roller can be further quickly moved. To the fixing temperature to further reduce the waiting time at startup,
The power consumption can be further reduced and the operating cost can be further reduced. In addition, the fixing quality can be prevented, and the image quality can be improved at low cost.

[Brief description of the drawings]

FIG. 1 shows an image fixing apparatus and an image fixing method according to a first embodiment of the present invention.
1 is a schematic front sectional view of a configuration of an image recording apparatus to which the embodiment is applied.

FIG. 2 is a partially enlarged side view of a fixing unit of the image recording apparatus of FIG.

FIG. 3 is a circuit block diagram of a main part of the image recording apparatus of FIG. 1;

FIG. 4 is a diagram showing a change in the surface temperature of the fixing roller over time when the rotation speed of the fixing roller is controlled at the time of warming-up of the image recording apparatus of FIG. 1;

FIG. 5 illustrates a second example of the image fixing device and the image fixing method of the present invention.
FIG. 3 is a circuit block diagram of a main part of an image recording apparatus to which the embodiment is applied.

FIG. 6 is a flowchart illustrating fixing roller rotation speed control processing by the image recording apparatus of FIG. 5;

7 is a diagram illustrating a change in the surface temperature of the fixing roller over time when the rotation speed of the fixing roller is controlled by the image recording apparatus of FIG. 5;

FIG. 8 shows a third example of the image fixing device and the image fixing method of the present invention.
FIG. 3 is a circuit block diagram of a main part of an image recording apparatus to which the embodiment is applied.

FIG. 9 is a flowchart illustrating fixing roller rotation speed control processing by the image recording apparatus of FIG. 8;

FIG. 10 is a diagram illustrating a change in the surface temperature of the fixing roller along with the progress of the number of rotations of the fixing roller when the rotation speed of the fixing roller is controlled by the image recording apparatus of FIG.

FIG. 11 is a plan view of a main part of a gear mechanism when the rotation speed of a fixing roller is switched by a gear mechanism.

FIG. 12 is a front view of a main part of the gear mechanism of FIG. 11;

FIG. 13 is a side cross-sectional view of an example of a fixing roller in which a heat generating member is disposed near a surface.

FIG. 14 is a diagram showing a change in the surface temperature of the fixing roller over time when an experiment using the fixing roller of FIG. 13 and a comparative experiment are performed.

FIG. 15 is a diagram showing a change in temperature on the surface of the fixing roller over time in a conventional method in which a fixing roller and a pressure roller are rotated at a rotation speed at the time of fixing immediately after power-on.

FIG. 16 is a diagram showing a change in the temperature of the surface of the fixing roller according to a conventional method in which the fixing roller and the pressure roller are stopped until immediately after the power is turned on until the surface temperature of the fixing roller rises to the fixing temperature.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image recording device 2 main body housing 3 recording unit 4 fixing unit 5 paper supply unit 10 photoconductor 11 charging unit 12 optical writing unit 13 developing unit 14 transfer unit 15 cleaning unit 16 static elimination unit 17 polygon motor 18 polygon mirror 19 reflection mirror Reference Signs List 20 recording paper 21 paper feed cassette 22 paper feed roller 23 registration roller pair 24 transport roller 30 upper case 31 fixing roller 32 lower case 33 pressure roller 34 heat generating member 35 temperature detection sensor 40 fixing roller temperature controller 41 rotation speed controller 42 Motor driver 43 Fixing roller drive motor 60 Image recording device 61 Timer 62 Rotation speed control unit 70 Image recording device 71 Rotation speed measurement unit 72 Rotation speed control unit 80 Gear mechanism 81 High speed gear 82 Low speed gear 82a Small diameter gear 82b Large diameter gear 83 Clutch Arm 84 Transmission gear 5 the motor gear 86 driven gear 90 fixing roller 91 base 92 heating member 93 a heat-resistant resin layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DA12 DC10 ED25 EE03 EF06 2H033 AA03 AA24 AA30 CA03 CA13 CA28

Claims (10)

[Claims] A fixing roller that is heated to a predetermined fixing temperature by a heat generating member and fixes the toner image transferred to the transfer paper onto the transfer paper; and a fixing roller pressed against the fixing roller to transfer the toner image onto the transfer paper. A pressure roller that presses the transfer paper against the fixing roller; a rotation driving unit that rotationally drives the fixing roller and the pressure roller; and a rotation speed of the fixing roller and the pressure roller that is controlled by the rotation driving unit. Rotation speed control means, temperature detection means for detecting the temperature of the fixing roller, and heating control of the fixing roller to a predetermined fixing temperature by controlling energization of the heating member based on a detection result of the temperature detection means. The fixing roller heated to the fixing temperature by the rotation speed control means via the rotation driving means during fixing, and the pressure roller. Image fixing for fixing the toner image on the transfer paper while the transfer paper on which the toner image is transferred is conveyed by the fixing roller and the pressure roller by rotating the toner image at a predetermined fixing rotation speed. In the apparatus, when the rotation speed control unit warms up until the fixing roller is heated to the fixing temperature, the surface temperature of the fixing roller detected by the temperature detection unit is lower by a predetermined temperature than the fixing temperature. Until the rotation switching temperature is reached, the rotation speeds of the fixing roller and the pressure roller are rotated at a warming-up rotation speed lower by a predetermined speed than the fixing rotation speed via the rotation driving unit, and thereafter, And an image fixing device that is driven to rotate at the fixing rotation speed. 2. A fixing roller which is heated to a predetermined fixing temperature by a heat generating member to fix a toner image transferred to a transfer sheet to the transfer sheet, and wherein the fixing roller is pressed against the fixing roller to transfer the toner image. A pressure roller that presses the transfer paper against the fixing roller; a rotation driving unit that rotationally drives the fixing roller and the pressure roller; and a rotation speed of the fixing roller and the pressure roller that is controlled by the rotation driving unit. Rotation speed control means, temperature detection means for detecting the temperature of the fixing roller, and heating control of the fixing roller to a predetermined fixing temperature by controlling energization of the heating member based on a detection result of the temperature detection means. The fixing roller heated to the fixing temperature by the rotation speed control means via the rotation driving means during fixing, and the pressure roller. Image fixing for fixing the toner image on the transfer paper while the transfer paper on which the toner image is transferred is conveyed by the fixing roller and the pressure roller by rotating the toner image at a predetermined fixing rotation speed. The apparatus further comprises a timer for counting an elapsed time from the start of the warm-up, wherein the rotation speed control unit is configured to start the warm-up when the warm-up is performed until the fixing roller is heated to the fixing temperature. From the time until a predetermined time is measured, the rotation speed of the fixing roller and the pressure roller is rotationally driven at a warming-up rotation speed lower by a predetermined speed than the fixing rotation speed via the rotation driving unit, An image fixing device, which is driven to rotate at the fixing rotation speed. 3. A fixing roller which is heated to a predetermined fixing temperature by a heat generating member and fixes the toner image transferred on the transfer paper to the transfer paper; and a fixing roller pressed against the fixing roller to transfer the toner image thereon. A pressure roller that presses the transfer paper against the fixing roller; a rotation driving unit that rotationally drives the fixing roller and the pressure roller; and a rotation speed of the fixing roller and the pressure roller that is controlled by the rotation driving unit. Rotation speed control means, temperature detection means for detecting the temperature of the fixing roller, and heating control of the fixing roller to a predetermined fixing temperature by controlling energization of the heating member based on a detection result of the temperature detection means. The fixing roller heated to the fixing temperature by the rotation speed control means via the rotation driving means during fixing, and the pressure roller. Image fixing for fixing the toner image on the transfer paper while the transfer paper on which the toner image is transferred is conveyed by the fixing roller and the pressure roller by rotating the toner image at a predetermined fixing rotation speed. The apparatus, further comprising at least a rotation speed detection unit that detects a rotation speed of the fixing roller, wherein the rotation speed control unit includes:
At the time of warming-up until the fixing roller is heated to the fixing temperature, the rotation of the fixing roller and the pressure roller via the rotation driving unit is performed until the rotation speed detection unit detects a predetermined rotation speed. The rotation speed is rotated at a warming-up rotation speed that is a predetermined speed lower than the fixing rotation speed, and when the rotation speed detection unit detects a predetermined rotation speed, the rotation speeds of the fixing roller and the pressure roller are changed during the fixing. An image fixing device, which is rotated at a rotation speed. 4. The method according to claim 1, wherein the rotation speed control means changes the rotation speed of the fixing roller and the pressure roller from the warming-up rotation speed to the fixing rotation speed.
4. The method according to claim 1, wherein a predetermined number of rotation speeds between the warming-up rotation speed and the fixing rotation speed are changed in a stepwise manner, or are changed continuously. 3. The image fixing device according to claim 1. 5. The image fixing device according to claim 1, wherein said heat generating member is disposed in a layered manner near a surface of said fixing roller. 6. A transfer in which a toner image is transferred by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressure roller pressed against the fixing roller at a predetermined rotation speed during fixing. In an image fixing method for fixing the toner image on the transfer paper while conveying paper while being held between the fixing roller and the pressure roller that are driven to rotate, a method in which the temperature of the fixing roller rises to the fixing temperature is performed. During the warm-up, the rotation speeds of the fixing roller and the pressure roller are set to a predetermined speed higher than the rotation speed during fixing until the surface temperature of the fixing roller reaches a rotation switching temperature lower than the fixing temperature by a predetermined temperature. An image fixing method comprising: rotating at a slow rotation speed during warm-up, and then rotating at the fixing speed. 7. A transfer in which a toner image is transferred by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressing roller pressed against the fixing roller at a predetermined fixing rotation speed. In an image fixing method for fixing the toner image on the transfer paper while conveying paper while being held between the fixing roller and the pressure roller that are driven to rotate, a method in which the temperature of the fixing roller rises to the fixing temperature is performed. During the warm-up, during a predetermined time from the start of the warm-up, the rotation speed of the fixing roller and the pressure roller is driven to rotate at a warm-up rotation speed lower by a predetermined speed than the fixing rotation speed, and thereafter, the rotation during the fixing is performed. An image fixing method characterized by rotating at a speed. 8. A transfer in which a toner image is transferred by rotating a fixing roller heated to a predetermined fixing temperature by a heat generating member and a pressure roller pressed against the fixing roller at a predetermined fixing rotation speed. In an image fixing method for fixing the toner image on the transfer paper while conveying paper while being held between the fixing roller and the pressure roller that are driven to rotate, a method in which the temperature of the fixing roller rises to the fixing temperature is performed. During the warming-up, the rotation speeds of the fixing roller and the pressure roller are reduced by a predetermined speed lower than the fixing rotation speed until the rotation speeds of the fixing roller and the pressure roller reach a predetermined rotation speed. When the rotation speed of the fixing roller and the pressure roller reaches the predetermined rotation speed, the fixing roller and the pressure roller are rotated. Image fixing method for causing the rotation speed of over La rotated at the fixing time of the rotational speed. 9. The image fixing method according to claim 1, wherein when the rotation speed of the fixing roller and the pressure roller is changed from the warming-up rotation speed to the fixing rotation speed, the warming-up rotation speed and the fixing rotation speed are changed. A predetermined number of rotation speeds between are changed stepwise and changed,
9. The image fixing method according to claim 6, wherein the image is continuously changed. 10. An image fixing method according to claim 6, wherein said heat generating member is disposed in a layered form near a surface of said fixing roller.