JPH08185085A - Image forming apparatus and fixing device control device - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of reducing the power consumption, and prolonging the service life of a thermal fixing unit, without increasing a cost. CONSTITUTION: The fixing unit is constituted so that the one hand of rollers is the conductive roller 117, and the field coil and the inductive magnetic material for combining the main magnetic fluxes generated by the field coil are disposed inside the conductive roller 117, and then the high frequency current supplying means is connected to the field coil. The other hand is the magnetic induction heat fixing unit 116 for performing the magnetic induction heat fixing, and the fixing unit 116 is heated to the sufficient temp. for starting the printing operation corresponding to the printing start signal, and then the temp. is controlled to become lower than the temp. required for the printing operation corresponding to the detection signal of the recording material allowed to pass the fixing unit 116, and moreover the heat is controlled to the sufficient temp. for starting the printing operation right before the leading end of the next recording material reaching the fixing unit 116.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording material using an electrophotographic process or the like, and a controller for a heat fixing device.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, an image forming unit is formed by an indirect (transfer) type or direct type electrophotographic process, an electrostatic recording process, a magnetic recording process, and various other known image forming principles and processes. To form a toner image, and transfer this toner image to a recording material such as transfer paper, printing paper, photosensitive paper, or electrostatic recording paper, and then fix it to the recording material with a heat roller type thermal fixing device to make it permanent. I'm getting an image.

This heat roller system uses a fixing roller having a heater therein and a pressure roller which is in pressure contact with the fixing roller, and a recording material is introduced and passed through a fixing nip portion between the pair of rollers. The unfixed toner image formed and carried on the recording material surface is fixed on the recording material surface by heat and pressure.

However, in the conventional heat roller type heat fixing device, since the heat capacity of the roller is large, there is a problem that it takes time for the roller to reach a predetermined fixing temperature after the heater which is a heat source is energized. .

Therefore, conventionally, the energization of the heater is
The image forming operation is configured to continue until the recording material is completely discharged.

[0006]

However, the above-mentioned conventional example has the following problems.

(1) By energizing the heater for more than the time required for the actual fixing operation (the time from the leading edge of the recording material entering the thermal fixing device to the trailing edge of the recording material passing through),
As the power consumption increases, the temperature inside the machine (temperature inside the image forming apparatus) also rises.

(2) Since the heater is energized for more than the time required for the actual fixing operation, the life of the thermal fixing device is shortened and the reliability is also lowered.

(3) When a small-sized recording material is continuously passed and fixed, the temperature of the non-sheet passing portion of the heat fixing device becomes high (partial overheated state of the heat fixing device), and the life of the heat fixing device is increased. Became shorter and the reliability was lower.

(4) In order to solve the above problem (3), a method has been proposed in which a plurality of heating units of a thermal fixing device are provided and the heating units are switched and controlled in accordance with recording materials of various sizes. However, this configuration has a problem that the cost of the product is increased.

A first invention according to the present application provides an image forming apparatus which can solve the above problems, reduce power consumption, and extend the life of a thermal fixing device without increasing the cost. To aim.

The second invention of the present application provides an image forming apparatus capable of further prolonging the life of the apparatus by performing more appropriate temperature control according to the environment and the like. Is intended.

Further, a third invention according to the present application is an image forming apparatus capable of reducing the power consumption as much as possible and extending the life of the apparatus while keeping the fixing device temperature at an appropriate temperature during the printing operation. Is intended to provide.

A fourth aspect of the present invention provides an image forming apparatus capable of extending the life of the apparatus by reducing the power consumption while controlling the temperature of the fixing device during fixing with high accuracy. It is intended to be provided.

Further, a fifth invention of the present application is to provide an image forming apparatus capable of achieving the above object in a laser beam printer for forming an image by a laser beam based on image data. There is.

A sixth aspect of the present invention provides a control device which can solve the above problems, reduce the power consumption and increase the life of the thermal fixing device without increasing the cost. With the goal.

Further, the seventh invention of the present application provides a control device capable of further prolonging the life of the device by performing more appropriate temperature control according to the environment and the like. It is an object.

The eighth invention of the present application provides a control device capable of reducing the power consumption as much as possible and extending the service life of the device while maintaining the temperature of the fixing device at an appropriate temperature during the printing operation. It is intended to be provided.

Further, a ninth invention according to the present application provides a control device capable of controlling the temperature of the fixing device at the time of fixing with high accuracy and reducing the power consumption to prolong the life of the device. The purpose is to do.

[0020]

According to the first invention of the present application, the above object is to cause a recording material to be fed and conveyed to form and carry a colored developer particle image, and to cause the recording material to carry the colored developer particles. An image forming apparatus for forming an image using an electrophotographic process by fixing an image with a fixing device, wherein the fixing device is a conductive roller in which at least one roller of a pair of rollers pressed against each other has a conductive layer. A field coil and an induction magnetic material that couples to a main magnetic flux generated in the field coil are provided inside the conductive roller, and the field coil has means for applying a high-frequency current. In an image forming apparatus which is a magnetic induction heating fixing device that is connected and performs magnetic induction heating fixing, the magnetic induction heating fixing device is
In response to the image formation start signal, the temperature is raised to a sufficient temperature to start the image formation operation, and in response to the signal that the conveyance recording material has passed through the magnetic induction heating fixing device, it is necessary for the image formation operation. By having a control device that is set to a temperature lower than the temperature and set to a temperature sufficient to start the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. To be achieved.

According to the second invention of the present application,
In the first aspect of the invention described above, the temperature lower than the temperature necessary for the image forming operation, which is to be controlled when it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device, is set to a value lower than that required for the previous image forming operation. This is achieved by setting the temperature corresponding to the temperature required for operation.

Further, according to the third invention of the present application, in the above-mentioned first invention, the image forming operation is performed immediately before the leading edge of the next conveyance recording material reaches the magnetic induction heating fixing device. This is achieved by setting the distance immediately before reaching the magnetic induction heating fixing device in accordance with the temperature required for the image forming operation when controlling the temperature to be sufficient for entering.

According to the fourth invention of the present application,
The above-mentioned object is, in the above-mentioned first invention, the temperature in the case of controlling to a temperature sufficient for starting the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device,
This can be achieved by setting the temperature corresponding to the temperature of the magnetic induction heating fixing device after a predetermined time has passed since the conveyed recording material passed through the magnetic induction heating fixing device.

Further, according to a fifth invention of the present application, the above-mentioned object is the image data of an image obtained by processing the code data of the inputted character or image in the above-mentioned first invention to the fourth invention. Image processing means for forming
A signal processing means for outputting a print start signal after the image data is formed by the image processing means, and a laser beam modulated corresponding to the image data formed by the image processing means are scanned by a polygon mirror on the photoconductor to form a latent image. A printing unit that forms the latent image and develops the latent image, and transfers the developed image to a recording material, a process control unit that manages the operation of the printing unit, and a paper feed detection unit that detects the supplied recording material. This is achieved by being a laser beam printer equipped with and.

According to the sixth invention of the present application,
The above-mentioned object is a fixing device for fixing a colored developer particle image on a recording material to the recording material by heat, wherein at least one roller of a pair of rollers pressed against each other is a conductive roller having a conductive layer, A field coil and an induction magnetic material that couples to the main magnetic flux generated in the field coil are provided inside the conductive roller, and the field coil is connected to a means for applying a high-frequency current. In a controller for a magnetic induction heating fixing device that performs magnetic induction heating fixing, the magnetic induction heating fixing device is heated to a temperature sufficient to start an image forming operation in response to an image forming start signal, and is conveyed. In response to the signal that the recording material has passed through the magnetic induction heating fixing device, the temperature is controlled to be lower than the temperature required for the image forming operation, and the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. Just before It is achieved by controlling the temperature sufficient to enter the forming operation.

Further, according to the seventh invention of the present application, the above object is achieved in the sixth invention, when it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device. This is achieved by setting the temperature to be controlled, which is lower than the temperature required for the image forming operation, corresponding to the temperature required for the previous image forming operation.

According to the eighth invention of the present application,
In the sixth aspect of the present invention, the magnetic induction heating fixing device is controlled when the temperature is sufficient to start the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. It is achieved by setting the distance immediately before reaching the temperature corresponding to the temperature required for the image forming operation.

Further, according to the ninth invention of the present application, in the above-mentioned sixth invention, the image forming operation is performed immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. Achieved by setting the temperature when controlling the temperature to be sufficient for entering, in accordance with the temperature of the magnetic induction heating fixing device after a lapse of a predetermined time after the conveyed recording material passes through the magnetic induction heating fixing device. It

[0029]

According to the first invention of the present application, as the fixing device, at least one roller of the roller pair that is in pressure contact with each other is a conductive roller having a conductive layer. A magnetic coil and an induction magnetic material that couples to a main magnetic flux generated in the field coil are provided, and a means for applying a high frequency current is connected to the field coil to perform magnetic induction heating fixing. Since a magnetic induction heating fixing device is used, this magnetic induction heating fixing device is a low heat capacity heating member as a heating member, and the temperature can be quickly raised to a target predetermined temperature for quick start (shortening of wait time). To be realized.

Moreover, the magnetic induction heating fixing device is heated to a temperature sufficient to start the image forming operation in response to the image forming start signal, and it is detected that the trailing edge of the recording material has passed through the fixing device. Then, during the paper interval (at the time of non-fixing), the temperature is once controlled to be lower than the temperature required for the image forming operation, but the image forming operation is started immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. Since the temperature is controlled to be sufficient, the temperature becomes a necessary temperature during the image forming operation (printing operation), and good fixing is performed.

Further, by changing to low temperature temperature control between sheets, the power consumption is reduced and the temperature inside the machine is lowered. Further, since the time for energizing the magnetic induction heating fixing device is reduced, the life of the magnetic induction heating fixing device is extended and the reliability is improved. Further, in the case of continuous conveyance of a small-sized recording material, transition to a low temperature temperature control between paper sheets can suppress an excessive temperature rise of the non-sheet passing portion of the magnetic induction heating fixing device. Further, the occurrence of the high temperature offset phenomenon can be suppressed and the image quality is improved.

According to the second invention of the present application,
In the first invention, control should be performed when it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device.
Since the temperature lower than the temperature required for the image forming operation is set in accordance with the temperature required for the previous image forming operation, the temperature control is performed more appropriately according to the environment, etc. Aim for a longer life.

Further, according to the third invention of the present application, in the above first invention, it is sufficient to start the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. When controlling the temperature to a proper temperature, the distance immediately before reaching the magnetic induction heating fixing device is set according to the temperature required for the next image forming operation. While maintaining the above, the time for controlling to a low temperature is extended to prolong the life of the device.

According to the fourth invention of the present application,
In the first aspect of the present invention, the temperature at which the temperature of the conveyed recording material is controlled by the magnetic induction heating when the temperature is controlled to a temperature sufficient for starting the image forming operation immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. Since the temperature is set according to the temperature of the magnetic induction heating fixing device after a lapse of a predetermined time after passing through the fixing device, the temperature of the fixing device during fixing is controlled with high accuracy to reduce power consumption and lengthen the device. Extend life.

Further, according to the fifth invention of the present application, the image forming apparatus of the first invention to the fourth invention is processed by processing the input character or image code data to obtain image data of the image. Image forming means, a signal processing means for outputting a print start signal after the image data is formed by the image processing means, and a laser beam modulated corresponding to the image data formed by the image processing means is exposed by a polygon mirror. Printing means for scanning the body to form a latent image, developing the latent image, and transferring the developed image to a recording material, process control means for controlling the operation of the printing means, and the supplied recording Since the laser beam printer is provided with the paper feed detecting means for detecting the material, even when the recording material transferred by the printing means is fixed, the appropriate temperature control is performed as described above. It is performed, and long life can be achieved.

According to the sixth invention of the present application,
As the fixing device, at least one roller of the roller pair is in pressure contact with each other and is a conductive roller having a conductive layer. Inside the conductive roller, a field coil and a main magnetic flux generated in the field coil are coupled. An induction magnetic material is provided, a means for applying a high frequency current is connected to the field coil, and a magnetic induction heating fixing device for performing magnetic induction heating fixing is used. The heater is a low-heat-capacity heating element as a heating element, and quickly raises the temperature to a target predetermined temperature to realize quick start property (shortening of wait time).

Moreover, the magnetic induction heating fixing device is heated to a temperature sufficient to start the image forming operation in response to the image forming start signal, and it is detected that the trailing edge of the recording material has passed through the fixing device. Then, during the paper interval (at the time of non-fixing), the temperature is once controlled to be lower than the temperature required for the image forming operation, but the image forming operation is started immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. Since the temperature is controlled to be sufficient, the temperature becomes a necessary temperature during the image forming operation (printing operation), and good fixing is performed.

Further, by changing to low temperature temperature control between sheets, the power consumption is reduced and the temperature inside the machine is lowered. Further, since the time for energizing the magnetic induction heating fixing device is reduced, the life of the magnetic induction heating fixing device is extended and the reliability is improved. Further, in the case of continuous conveyance of a small-sized recording material, transition to a low temperature temperature control between paper sheets can suppress an excessive temperature rise of the non-sheet passing portion of the magnetic induction heating fixing device. Further, the occurrence of the high temperature offset phenomenon can be suppressed and the image quality is improved.

Further, according to the seventh invention of the present application, in the sixth invention, the image formation to be controlled when it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device. Since the temperature lower than the temperature required for the operation is set according to the temperature required for the previous image forming operation, more appropriate temperature control is performed according to the environment etc., and the life of the device is further extended. Plan.

According to the eighth invention of the present application,
In the sixth aspect of the invention, immediately before the magnetic induction heating fixing device is reached, when the temperature is controlled to a temperature sufficient for starting the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. The distance is set according to the temperature required for the next image forming operation.Therefore, while maintaining the fixing device temperature at an appropriate temperature during the image forming operation, the time for controlling the temperature to a low temperature is lengthened and the apparatus length is increased. Aim for a longer life.

Further, according to the ninth invention of the present application, in the above-mentioned sixth invention, it is sufficient to start the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. Since the temperature in the case of controlling to a proper temperature is set in accordance with the temperature of the magnetic induction heating fixing device after a predetermined time has passed since the conveyed recording material passed through the magnetic induction heating fixing device,
The temperature of the fixing device during fixing is controlled with high accuracy to reduce power consumption and prolong the life of the device.

[0042]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described.

(1) Configuration of Image Forming Apparatus FIG. 15 is a side sectional view showing the structure of the image forming apparatus of this embodiment, and FIG. 16 is a block diagram of the electric circuit of this embodiment.

The structure of the image forming apparatus will be described below. In FIG. 16, reference numeral 1 is a power supply SW, which turns on the power of the image forming apparatus.
Used to turn N / OFF. 2 is a noise filter that reduces noise generated by the image forming apparatus so as not to propagate to the AC line. A magnetic induction heating fixing device control unit 3 detects the temperature of the magnetic induction heating fixing heater, which is a heat source for heat fixing, by the temperature sensor 5, and the engine controller 105 performs ON / OFF control so that the temperature becomes constant. Used to do. A low voltage power supply unit 4 generates a voltage required to operate the image forming apparatus.

Reference numeral 101 denotes a host I / I provided in the video controller section 100 which is an image processing means and a signal processing means.
The F circuit is used to control the reception of code data from the host computer and input the code data to the video controller 103. Video controller 1
03 is a CPU 103a, a RAM 103b, a ROM 10
3c, buffer 103d, non-volatile storage medium 103f,
It is composed of a video I / F circuit 21, develops code data from a host computer into a dot image, stores it in a buffer 103d, transfers the dot image to an engine controller 105 as a process control means through the video I / F circuit 21, and controls the display. Display control and input control of the operation panel 104 are performed.

A nonvolatile recording medium (NVRAM, E
The EPROM 103f stores initial information necessary for controlling the image forming apparatus. Various information set by the user using the display / operation panel 104 and information set by the control program of the image forming apparatus are stored even after the power is turned off so that the set state is restored at the time of restarting. It is for.

Reference numeral 102 denotes an engine section, which is composed of printing means required for the image forming apparatus to output an image on a recording medium by an electrophotographic process, and process control means for controlling the printing means.

Reference numeral 13 is a main motor, and the engine controller 105 outputs the signal from the main motor driver 14 to the O level.
By N / OFF control, the photosensitive drum 112, which is the photosensitive member, the developing device 113, the transfer roller 114, the cleaner 115, the magnetic induction heating fixing roller 117, and the pressure roller 1 shown in FIG.
18, the rollers such as a conveyance roller (not shown) are rotationally controlled to control the conveyance of the recording material.

A scanner motor 11 reflects a laser beam generated by the laser diode 107 in the horizontal direction (main scanning direction) and hits the longitudinal direction of the photosensitive drum 112 to form a latent image on the polygon mirror 108. Rotate.
The scanner motor driver 12 that controls the rotation of the polygon mirror 108 controls the rotation of the scanner motor 11 to be constant.

This laser light is emitted from the video controller 10
The dot image created by 3 is converted into a video signal, and the engine controller 10 is converted through the video I / F circuit 21.
Then, the laser driver 106 controls the laser diode 107 to adjust the intensity of the laser light and modulate it with a video signal to irradiate the laser beam.

The light receiving element 8 receives the laser beam reflected by the polygon mirror 108, converts it into an electric signal, and transmits it to the BD circuit 9. The BD circuit 9 shapes this signal and sends it to the video controller 103 as a horizontal synchronizing signal. Therefore, the light receiving element 8 is arranged in the horizontal direction (main scanning direction).
Is placed outside the photosensitive drum 112 and generates a signal for each horizontal scanning.

The temperature sensor 5 detects the temperature of the fixing device 116 to perform magnetic induction heating fixing, and outputs a signal to the engine controller 105. Engine controller 10
Reference numeral 5 controls the magnetic induction heating fixing device controller 3 based on this temperature signal. Regarding the configuration of the magnetic induction heating fixing device,
Details will be described in (3). Regarding the control operation, (4)
Will be described in detail.

The high-voltage power source 10 is used for primary charging the photosensitive drum 112, developing voltage for developing a latent image formed on the photosensitive drum 112 with toner, and transferring the latent image on the recording material from the photosensitive drum 112. Transfer bias, a separation voltage for separating the recording material from the photosensitive drum 112,
A transfer device cleaning bias or the like for separating unnecessary toner from the transfer roller 114 is generated. These voltages are applied to the primary charger 111, the developing device 113 (developing cylinder, etc.), the transfer roller 114, the transfer device cleaner (not shown), and the separator (not shown). Engine controller 10
5 controls the timing of generating these voltages.

The pickup solenoid 22 is controlled by the engine controller 105 to feed the recording material one by one.

The fan motor 6 is a fixing device 116 after printing.
Is used to control the temperature rise of each element forming the image forming apparatus and the fan motor driver 7 controls the rotation.

The engine controller 105 is the CPU 1
05a, RAM105b, ROM105c, video I /
A series of control sequences configured by the F circuit 21 for feeding a recording material and performing printing control using an electrophotographic process, communication control with a video controller, control of each component of an engine unit, electrophotographic process sequence Exception handling control of.

(2) Outline of Operation of Image Forming Apparatus The video controller section 100 develops code data from the host computer into bitmap information which is image information. The bitmap data is temporarily stored in the image memory (buffer) 103d of the video controller 103. The video controller 103 in which the image of one page is stored requests the engine unit 102 to prepare for image output.

Next, the engine controller 105 starts the control so that the printing is possible, starts up each element constituting the engine section 102, and the main motor 13
Then, the rotation control of the scanner motor 11 is started. Then, the control of the magnetic induction heating fixing device 116 is started so that the temperature of the magnetic induction heating fixing device 116 becomes the fixing possible temperature,
The laser light amount is controlled to control and adjust the laser driver 106 so as to obtain a predetermined light amount. When the adjustment of the scanner motor 11 and the laser light amount is completed, the signal detected by the light receiving element 8 is shaped by the BD circuit 9, and the BD signal is monitored to determine whether or not there is any abnormality. After determining that the control is normal, the pickup solenoid 2
2 is turned on to feed the recording material.

The timing at which the fed recording material passes through the paper feed sensor 18 is detected, and the leading edge synchronizing signal (vertical synchronizing signal) of the recording material and the horizontal synchronizing signal (BD) are sent to the video controller 103. Signal).
The video controller 103 uses the dot image of the buffer 103d as a video signal for each column in the horizontal direction,
It is sent to the engine unit 102 in synchronization with a horizontal synchronizing signal. The engine controller 105, except for the area where an image can be formed on the recording material (image printable area) and the timing at which the light receiving element 8 detects the laser beam,
The video signal is masked so that 07 does not emit light. The masked video signal modulates the laser light by the laser driver 106 and the laser diode 107, and the laser light is reflected by the polygon mirror 108 to expose the photosensitive drum 112.

On the other hand, the engine controller 105 controls the high voltage power source 10 to generate a primary charging voltage VPr for primary charging the photosensitive drum 112 so that an image can be formed from the front end of the recording material. As a result, the photosensitive drum 112
Is negatively charged by this primary charging voltage, and at the same time, the transfer device cleaning bias V is applied to the transfer device cleaner.
The application of Tc is started to start cleaning the transfer device.

Next, the surface of the photosensitive drum 112 is neutralized by exposure to laser light, and a latent image is formed on the portion exposed to laser light. On the other hand, the developing device 113
To the photosensitive drum 112 having a negative potential because the developing voltage VDP is applied to the toner and the toner is negatively charged.
The toner is transferred to a bright portion having a higher electric potential than the dark portion, and the bright portion is developed. Then, the developed toner on the photosensitive drum 112 is conveyed to a portion facing the transfer roller 114, and a transfer bias VTr having a positive potential is applied to the transfer roller 114, so that the toner charged negatively is recorded. Be attracted to. The transferred recording material is
Since it is charged, it is guided to the magnetic induction heating fixing device 116 after being discharged by the discharging needle, and is fixed by the magnetic induction heat pressure fixing device 116.

Then, the video controller 103 develops the image information of the next page into an image, and when the data is developed into the bitmap, issues a command to the engine section 102 to re-feed the sheet. As a result, the bitmap data is output to the recording material on the next page, and the recording material on which the image has been fixed by passing through the magnetic induction heating fixing device 116 is discharged along the image print conveyance path. An image is formed on the recording material through such a process.

(3) Structure of Magnetic Induction Heating Fixing Device FIG. 2 shows the heating means of the fixing roller of the present invention.
Reference numeral 1030 denotes a high frequency converter for supplying a high frequency current to the field coils 1100 to 1103 arranged inside the fixing roller 117 which is a conductive roller.

The field coils 1100 to 1103 are arranged inside the fixing roller cylinder as shown in FIG. Although various configurations of the coil are possible, four sets of coils (1100 to 1103) are connected in series in FIG.

With this configuration, the high frequency converter 1030
When a higher frequency current is generated and applied, the field coil 11
00 to 1103 apply a high frequency magnetic field to the metal on the opposite surface, that is, the inner surface of the roller cylinder by the high frequency current.
When the high-frequency magnetic field is applied to the cylinder metal, the magnetic flux forms a loop loop that starts from the center of the coil that gives the magnetomotive force and returns to the center of the coil with the route of minimum reluctance. That is, the space (μ0) and the nonmagnetic metal portion are minimized to form a system that follows the path.

Therefore, although not shown in FIG. 2, a magnetic circuit, that is, a magnetic path made of a member having a high magnetic permeability is formed inside so that the magnetic flux is efficiently coupled to and penetrates the metal member of the roller cylinder. There is.

FIG. 3 shows how the high frequency converter 1030 supplies switching power to the model having such a configuration. In FIG. 3, a commercial AC input from a line is rectified by a double-wave rectifier 1200, and a field coil 1 is passed through a switching semiconductor (FET) 1201.
100 to 1103, and high frequency switching is performed by the switching semiconductor 1201. Further, since the fixing roller 117 is formed with the magnetic coupling as described above, it can be represented by the same equivalent circuit as the switching transformer of the power supply.

As described above, since the heating element is the metal fixing roller itself, the heat conduction model from the heat source can be realized with an extremely monotonous structure. It is possible to obtain a stable fixing temperature.

(4) Printing operation and magnetic induction heating fixing device temperature control operation FIG. 4 is a flowchart of the video controller 100.
FIG. 5 is a flowchart of the engine unit, and FIGS. 6 to 8 are timing charts of the startup magnetic induction heating fixing device temperature control control operation.

As shown in FIG. 4, the video controller section 100 stands by until image code data is sent from an external device such as a host computer (step S1).
01), when the code data is received, the code data is expanded into video data by the video controller 103 shown in FIG. 16 (step S103). Then, it is judged from the code data whether or not the expansion of the video data for one page is completed (step S104), and if it is not completed, this judgment is repeated.
2 to command the start of printing to the video I / F circuit 2
The print start signal which is the signal 1 is set to "L" (step S105).

As a result, in order to start the printing operation, the engine section 102 drives the paper feeding roller 121 by the paper feeding solenoid 22 to start the paper feeding operation, and the scanner motor driver 12 starts the polygon motor driving. Pretreatment such as uniformly charging the surface of the photosensitive drum 112 is performed.

Then, the video controller section 100 waits for the sub-scanning synchronizing signal to be sent out via the video I / F 21 (step S106), and when the sub-scanning synchronizing signal is received, the print start signal is set to "H". “(Step 107), one page is printed (Step S10
8) Then, the process returns to the code data receiving routine again (step S101).

Next, in the engine section 102, immediately after the power is turned on, as shown in FIG. 5, initial setting for controlling the magnetic induction heating fixing device is performed (step S201). The magnetic induction heating and fixing device control is performed by energizing the magnetic induction heating and fixing device 116 for an arbitrary period during a predetermined period, and has two modes in which the current temperature is lower and higher than the target temperature. On the other hand, it is performed by changing the energization time when the current temperature is low (hereinafter, referred to as H mode time) and the energization time when the current temperature is high (hereinafter, referred to as L mode time). In this embodiment, the temperature rising rate of Table 1 is 70 (deg /
The target temperature is set to 155 ° C. by selecting the H mode time and the L mode time according to the primary AC input voltage in the above S).

[0075]

[Table 1]

Next, the process waits for a print start signal from the video controller section 100 (step S202), and if the print start signal is not "L", a process for stopping the entire drive system to reduce power consumption is performed. The control is stopped (step S203). If the print start signal is "L", it is monitored whether the low-temperature magnetic induction heating fixing device control (step S211) described later is being executed (step S20).
4) If it is not being executed, the temperature of the magnetic induction heating fixing device 116 is monitored (step S206), and if it is equal to or higher than the startup ready temperature (130 ° C.), the step S2 described later will be performed.
If the temperature is lower than the ready temperature (130 ° C.) for the normal magnetic induction heating fixing device control of No. 09, “starting magnetic induction heating fixing device control” is performed (step S207). Details of the "control of the magnetic induction heating and fixing device for start-up" will be described with reference to FIGS.

First, the engine controller 105 sets C
It is equipped with a PU 105a, and is RA by the CPU 105a.
The control register secured in M105b is activated to control the magnetic induction heating fixing device. That is, as shown in FIG. 6, it is judged whether or not the control register is 0 (step S301), and if 0, the rising energization time of Table 2 is selected by the AC input voltage and the temperature monitoring timer is started. Then, the control register is set to 1 (step S302), and the process proceeds to a startup control timer monitoring routine (step S316 shown in FIG. 8) described later.

[0078]

[Table 2]

On the other hand, when the control register is not 0, it is judged whether it is 1 (step S303), and when it is 1, the temperature monitoring timer is monitored (step S303).
304). If the temperature monitoring timer value is 6.0 sec or more, the startup energization time is increased by 10 msec (step S306), the temperature monitoring timer is reset, and the control register is set to 2 (step S30).
7) Then, the process proceeds to a startup control timer monitoring routine (step S316 shown in FIG. 8) described later.

However, the temperature monitoring timer value is 6.0 sec.
If less, the temperature of the magnetic induction heating fixing device is monitored (step S305). If the temperature of the magnetic induction heating fixing device is 90 ° C. or higher, the temperature monitoring timer is set to the same value as when the temperature monitoring timer value is 6.0 sec or more. After resetting and setting the control register to 2 (step S307), if the temperature of the magnetic induction heating fixing device is lower than 90 ° C., the process proceeds to the start-up control timer monitoring routine (step S316 shown in FIG. 8) which will be described later. Transition.

If the control register is not 1, the control register is set to 2 as shown in FIG.
It is determined whether or not (step S308), and if the control register is 2, the temperature monitoring timer is monitored (step S309). If the temperature monitoring timer is stopped, the temperature of the magnetic induction heating fixing device is monitored (step S3).
10) If the temperature is lower than 130 ° C., the routine proceeds to a startup control timer monitoring routine (step S316 shown in FIG. 8) described later, and if the temperature is 130 ° C. or higher, the temperature monitoring timer is started (step S311).

After the temperature monitoring timer is started in this way, or when it is determined that the timer is operating in the temperature monitoring timer monitoring routine, the temperature of the magnetic induction heating fixing device is then monitored ( Step S312), 14
If the temperature is lower than 0 ° C., the process proceeds to the startup control timer monitoring routine (step S316 shown in FIG. 8) described later.
If the temperature is 140 ° C. or higher, the target temperature of Table 3 in the normal magnetic induction heating fixing device control, the H mode time and the L mode time of Table 1 above are set, the temperature monitoring timer is reset, and the control register is set to 3. (Step S31
3), the process proceeds to the startup control timer monitoring routine (step S316 shown in FIG. 8) described later.

[0083]

[Table 3]

On the other hand, if the control register is not 2, the temperature of the magnetic induction heating fixing device is monitored (step S314), and if it is less than 150 ° C., the startup control timer monitoring routine described later (step shown in FIG. 8). S31
If the temperature is 150 ° C. or higher, the control register is set to 0, the startup control timer is reset, the magnetic induction heating fixing device drive is stopped, and the startup magnetic induction heating fixing device control routine is exited. (Step S31
5).

The temperature of the magnetic induction heating fixing device is 150
As shown in FIG. 8, the start-up control timer is monitored until the temperature exceeds the temperature (step S316). If the start-up control timer is stopped, the start-up control timer is started and the magnetic induction heating fixing device 116 is started. After the start of driving (step S317), if the start-up control timer is operating, the start-up control timer is monitored (step S318), and if the start-up control timer value is less than the start-up energization time. For example, the process exits from the "startup time induction heating fixing device control" routine.

However, if the startup control timer value is equal to or longer than the startup energization time, the magnetic induction heating fixing device drive is stopped (step S319), and the startup control timer is monitored again (step S320) to start up. If the control timer value is less than 200 msec, this "startup time induction heating fixing device control" routine is directly terminated.
If it is msec, the start-up control timer is reset (step S321), and then this "start-up timing induction heating fixing device control" routine is exited.

The above is the details of the startup magnetic induction heating fixing device control in step S207 of FIG.

After exiting from such a "startup magnetic induction heating and fixing device control" routine, as shown in FIG. 5, the processing state of this "startup magnetic induction heating and fixing device control" is monitored (step If the magnetic induction heating fixing device temperature exceeds 150 ° C. and the “start-up magnetic induction heating fixing device control” is completed (S208), the “normal magnetic induction heating fixing device control” is performed (step S209). Details of the "control of the normal magnetic induction heating fixing device" will be described with reference to FIG.

First, as shown in FIG. 9, the operating state of the normal magnetic induction heating fixing device control timer is monitored (step S
401), if the operation is in progress, the routine proceeds to a fixing ON flag monitoring routine (step S410) which will be described later.
402), if the temperature is equal to or higher than the target temperature, the magnetic induction heating fixing ON flag installed in the RAM area is reset to
The L mode monitoring counter installed in the area is incremented by 1, and the H mode monitoring counter installed in the RAM area is cleared (step S403). However, if the temperature is lower than the target temperature, the magnetic induction heating fixing ON flag installed in the RAM area is set, the H mode monitoring counter installed in the RAM area is incremented by 1, and the L mode monitoring counter installed in the RAM area. Is cleared (step S40
4).

Then, the counter value of the H mode monitoring counter is monitored (step S405). If it is 7, the H mode monitoring counter is cleared and the H mode time is set to 10 ms.
ec is increased, while the L-mode time is decreased by 10 msec (step S407).

However, if it is not 7, the counter value of the L mode monitor counter is monitored (step S406),
If it is 7, the L-mode monitoring counter is cleared to reduce the L-mode time by 10 msec and increase the H-mode time by 20 msec (step S408).

After checking the H mode monitoring counter and the L mode monitoring counter in this way, the normal magnetic induction heating fixing device control timer is started to start driving the magnetic induction heating fixing device (step S409).

Then, the fixing ON flag is monitored (step S410), and if it is set, it is determined whether the normal magnetic induction heating fixing device control timer is equal to or longer than the H mode time (step S411). And if it is less than H mode time,
This "normal magnetic induction heating fixing control" routine is exited, but if it is the H mode time or more, the magnetic induction heating fixing device 11
The driving of No. 6 is stopped (step S413).

If the fixing ON flag is reset, it is judged whether the normal magnetic induction heating fixing control timer is longer than the L mode time (step S412). Although the "heat fixing control" routine is terminated, if the L mode time or longer, the drive of the magnetic induction heating fixing device 116 is stopped (step S413).

After the driving of the magnetic induction heating fixing device 116 is stopped in this way, the normal magnetic induction heating fixing device control timer is monitored (step S414), and the timer value is 140 m.
If it is less than sec, the "normal magnetic induction heating and fixing device control" routine is directly exited, but the timer value is 140 msec.
Then, the normal magnetic induction heating and fixing device control timer is reset (step S415), and the "normal magnetic induction heating and fixing control" routine is exited.

The above is the details of the control of the normal magnetic induction heating fixing device in step S209 of FIG.

After the control of the normal magnetic induction heating fixing device is completed, as shown in FIG. 5, a predetermined time has passed after the trailing edge of the print conveying paper P has passed through the paper feed sensor 18, that is, the print conveying paper. It is judged whether or not the rear end of P has reached the magnetic induction heating fixing device 116 (step S210), and when it is detected that it has reached the end, the normal magnetic induction heating fixing device control is terminated and the normal magnetic induction heating fixing device is terminated. Reset the device control timer to perform "low temperature magnetic induction heating fixing control" (step S
211).

Details of the "control of the low temperature magnetic induction heating fixing device" will be described with reference to FIG.

First, as shown in FIG. 10, the target temperature for the low temperature magnetic induction heating fixing device control is set as shown in Table 4 (step S501).

[0100]

[Table 4]

Then, the operating state of the forced stop timer is monitored (step S502). If the forced stop timer is stopped, the forced stop timer is started to stop the driving of the magnetic induction heating fixing device 116 (step S503), and then the operation is started. If it is medium, monitor the forced stop timer as it is (step S504),
If the forced stop timer value is less than 300 msec, the forced stop timer operating state monitoring routine (step 50) is executed again.
Returning to 2), if the forced stop timer value is 300 msec or more, the forced stop timer is reset and the target temperature of the next normal magnetic induction heating fixing device control is set as shown in Table 5 according to the magnetic induction heating fixing device temperature at that time. The setting is performed (step S505), and the subsequent low-temperature magnetic induction heating fixing process is performed.

[0102]

[Table 5]

First, the operating state of the low-temperature magnetic induction heating fixing device control timer is monitored (step S506), and if it is in operation, the fixing ON flag monitoring routine (step S51).
Go to 1). However, if it is in the stopped state, the low temperature magnetic induction heating fixing device control timer is started (step S5).
07), the temperature of the magnetic induction heating fixing device is monitored (step S508). As a result, if the magnetic induction heating fixing device temperature is lower than the low temperature target temperature, the fixing ON flag is set (step S509), and if it is higher than the low temperature target temperature, the fixing ON flag is reset (step S510).

Thereafter, the fixing ON flag is monitored (step S511), and if reset, the driving of the magnetic induction heating fixing device 116 is stopped (step S513). If it is set, the low temperature magnetic induction heating fixing device control timer is set. Monitoring (step S512), if the timer value is 100 msec or more, driving of the magnetic induction heating fixing device 116 is stopped (step S513), and if the timer value is less than 100 msec, driving of the magnetic induction heating fixing device 116 is started. (Step S514).

Then, the low temperature magnetic induction heating fixing device control timer is monitored again (step S515), and the timer value is set to 1
If it is 40 msec, the low temperature magnetic induction heating fixing device control timer is reset (step S516), and if the timer value is less than 140 msec, this "low temperature magnetic induction heating fixing device control" routine is exited.

However, when the "low temperature magnetic induction heating fixing device control" routine is entered next, a low temperature magnetic induction heating fixing device control timer monitoring routine (step S50)
Control is performed from 6).

The above is the details of the control of the low temperature magnetic induction heating fixing device in step S211 of FIG.

After exiting the control routine of the low-temperature magnetic induction heating fixing device, the engine controller 105 outputs the / TOP signal of the video I / F circuit 21 which is a sub-scanning synchronizing signal to the video controller as shown in FIG. From the timing sent to 103, it is monitored whether or not it is time to start feeding (step S212). If it is the feeding start timing, the first video controller waits for a print start signal (step S202). Return.

At this time, if the print start signal is "L", the execution state of the above-mentioned low temperature magnetic induction heating fixing device control is monitored (step S204). According to the set target temperature of the normal magnetic induction heating fixing device, the / TOP signal is measured from the timing when it is sent to the video controller 103 (step S205), and the temperature of the magnetic induction heating fixing device described above is established at the predetermined timing of Table 6. Then, the routine proceeds to a determination routine (step S206) as to whether or not it is ready for raising.

[0110]

[Table 6]

FIG. 1 shows a timing chart for controlling the magnetic induction heating fixing device and a change in the fixing device temperature. As is clear from the figure, according to this embodiment, the magnetic induction heating fixing device is heated to a temperature sufficient to start the printing operation in response to the print start signal, and the trailing edge of the recording material is Fixing device 1
Since it is detected that the sheet has passed through 16 and is controlled to a temperature lower than the temperature required for the printing operation once between the sheets (when the image is not fixed), the power consumption is reduced and the temperature inside the apparatus is lowered. further,
Since the time to energize the magnetic induction heating fixing device is reduced,
The life of the magnetic induction heating fixing device is extended and the reliability is improved. Further, in the case of continuous conveyance of a small-sized recording material, transition to a low temperature temperature control between paper sheets can suppress an excessive temperature rise of the non-sheet passing portion of the magnetic induction heating fixing device. Further, the occurrence of high temperature / temperature offset and development can be suppressed, and the image quality is improved.

Then, the temperature is controlled to a temperature sufficient for starting the printing operation immediately before the leading edge of the next recording material to be conveyed reaches the magnetic induction heating fixing device. Is done.

As described above, it is possible to extend the life of the fixing device without increasing the cost as compared with the conventional fixing device.

The contents described above are merely examples, and the numerical values in Tables 1 to 6 and the numerical values in the description can be changed as a matter of course.

The method for realizing the startup magnetic induction heating fixing device control (step S207) and the normal magnetic induction heating fixing device control (step S209) in FIG. 5 is not limited to this.

(Second Embodiment) This embodiment is shown in FIG. 11 between the print start signal monitoring routine (step S202) and the process control stop routine (step S203) of FIG. 5 in the first embodiment. The processing shown in FIG.
The engine controller 105 receives the pseudo print start signal via the F circuit 21.

That is, in FIG. 11, the pseudo print start signal is waited (step S2020), and if it is at "H" level, the above-mentioned process control stop routine (step S2).
Move to 03). However, if it is at the "L" level, paper feeding is started, and at that time, it is judged whether or not the low-temperature magnetic induction heating fixing device control is already being continued (step S2021). The process proceeds to the device control routine (step S207). However, if the magnetic induction heating and fixing device control is not started, that is, if it is the first printing operation, it waits for the leading edge of the paper to reach the paper feed sensor (step S2022). The process proceeds to a determination routine (step S206) as to whether or not the temperature of the heat fixing device is ready to start up.

As described above, according to this embodiment, even in the image forming apparatus for performing pseudo printing, the same control as that in the first embodiment can be performed, and the life of the apparatus can be extended.

(Third Embodiment) In this embodiment, as can be seen from the timing chart and temperature change shown in FIG. 12 in the first embodiment, it is detected that the paper has passed through the magnetic induction heating fixing device. At this time, the control temperature in the low-temperature magnetic induction heating fixing device control is set corresponding to the control temperature in the normal induction heating fixing device control in the previous image forming operation. Therefore, according to the present embodiment, it is possible to control the low-temperature magnetic induction fixing device more appropriately according to the environment and the like, and it is possible to further prolong the life of the device.

(Fourth Embodiment) In this embodiment, as can be seen from the timing chart and temperature change shown in FIG. 13, the image forming operation is performed immediately before the leading edge of the next paper reaches the magnetic induction heating fixing device. When the temperature is controlled to be sufficient for entering, the distance immediately before reaching the magnetic induction heating fixing device is set according to the temperature required for the next image forming operation.

Therefore, according to the present embodiment, it is possible to sufficiently secure the execution time of the low-temperature magnetic induction fixing device control before the start of the printing operation, while maintaining the fixing device temperature at an appropriate temperature at the start of the printing operation. Therefore, the life of the device can be extended.

(Fifth Embodiment) As can be seen from the timing chart and the temperature change shown in FIG. 14, the fifth embodiment performs the image forming operation immediately before the leading edge of the next paper reaches the magnetic induction heating fixing device. The temperature in the case of controlling the temperature to be sufficient for entering is set in accordance with the temperature of the magnetic induction heating fixing device after a predetermined time has elapsed since the conveyed recording material passed through the magnetic induction heating fixing device.

Before printing the first sheet, the system temperature of the fixing device is low (room temperature), and therefore the ringing of the temperature at the time of rising to the temperature for starting image formation is large. Since the temperature of the system is higher than room temperature, temperature ringing at the time of rising to a temperature for entering image formation is small.

Therefore, the temperature of the fixing device during fixing can be controlled with high accuracy by changing the target setting for temperature control.

[0125]

As described above, the first aspect of the present application
According to the invention, the magnetic induction heating fixing device is heated to a temperature sufficient to start the image forming operation in response to the image forming start signal, and it is detected that the trailing edge of the recording material has passed through the fixing device. Then, during the paper interval (at the time of non-fixing), the temperature is once controlled to be lower than the temperature required for the image forming operation, but the image forming operation is started immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. Since the temperature is controlled to be sufficient, the temperature can be set to a required temperature during the image forming operation (printing operation), and good fixing can be performed.

Further, by changing to low temperature temperature control between sheets, it is possible to reduce power consumption and lower the machine temperature. Further, since the time for energizing the magnetic induction heating fixing device is reduced, the life of the magnetic induction heating fixing device is extended and the reliability can be improved.
Further, in the case of continuous conveyance of a small-sized recording material, it is possible to suppress excessive temperature rise in the non-sheet passing portion of the magnetic induction heating fixing device by changing to low temperature temperature control between sheets. Further, the occurrence of the high temperature offset phenomenon can be suppressed, and the image quality can be improved.

According to the second invention of the present application,
In the first invention, control should be performed when it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device.
Since the temperature lower than the temperature required for the image forming operation is set according to the temperature required for the previous image forming operation, it is possible to perform more appropriate temperature control according to the environment and the like, and to further improve the apparatus. It is possible to extend the life of the.

Further, according to the third invention of the present application, in the above first invention, it is sufficient to start the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. When controlling the temperature to a proper temperature, the distance immediately before reaching the magnetic induction heating fixing device is set according to the temperature required for the next image forming operation. It is possible to prolong the service life of the apparatus by prolonging the time for controlling the temperature to be low while keeping the above.

According to the fourth invention of the present application,
In the first aspect of the present invention, the temperature at which the temperature of the conveyed recording material is controlled by the magnetic induction heating when the temperature is controlled to a temperature sufficient for starting the image forming operation immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. Since the temperature is set according to the temperature of the magnetic induction heating fixing device after a lapse of a predetermined time after passing through the fixing device, the temperature of the fixing device during fixing is controlled with high accuracy to reduce power consumption and lengthen the device. The life can be extended.

Further, according to the fifth invention of the present application, the image forming apparatus of the first invention to the fourth invention processes the image data of the image by processing the code data of the inputted character or image. Image forming means, a signal processing means for outputting a print start signal after the image data is formed by the image processing means, and a laser beam modulated corresponding to the image data formed by the image processing means is exposed by a polygon mirror. Printing means for scanning the body to form a latent image, developing the latent image, and transferring the developed image to a recording material, process control means for controlling the operation of the printing means, and the supplied recording Since the laser beam printer is provided with the paper feed detecting means for detecting the material, even when the recording material transferred by the printing means is fixed, the appropriate temperature control is performed as described above. Can be performed, it is possible to increase the life of.

According to the sixth invention of the present application,
In response to the image formation start signal, the magnetic induction heating fixing device is heated to a temperature sufficient to start the image forming operation, and it is detected that the trailing edge of the recording material has passed through the fixing device and the paper interval (non- At the time of fixing), the temperature is once controlled to a temperature lower than the temperature required for the image forming operation, but is controlled to a temperature sufficient to enter the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. Therefore, during the image forming operation (printing operation), the temperature can be raised to a required temperature, and good fixing can be performed.

Further, by changing to low temperature temperature control between sheets, it is possible to reduce power consumption and lower the temperature inside the machine. Further, since the time for energizing the magnetic induction heating fixing device is reduced, the life of the magnetic induction heating fixing device is extended and the reliability can be improved.
Further, in the case of continuous conveyance of a small-sized recording material, it is possible to suppress excessive temperature rise in the non-sheet passing portion of the magnetic induction heating fixing device by changing to low temperature temperature control between sheets. Further, the occurrence of the high temperature offset phenomenon can be suppressed, and the image quality can be improved.

Further, according to the seventh invention of the present application, in the sixth invention, the image formation to be controlled when it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device. Since the temperature lower than the temperature required for the operation is set in accordance with the temperature required for the previous image forming operation, it is possible to perform more appropriate temperature control according to the environment, etc. The life can be extended.

According to the eighth invention of the present application,
In the sixth aspect of the invention, immediately before the magnetic induction heating fixing device is reached, when the temperature is controlled to a temperature sufficient for starting the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. The distance is set according to the temperature required for the next image forming operation.Therefore, while maintaining the fixing device temperature at an appropriate temperature during the image forming operation, the time for controlling the temperature to a low temperature is lengthened and the apparatus length is increased. The life can be extended.

Further, according to the ninth invention of the present application, in the sixth invention, it is sufficient to start the image forming operation immediately before the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. Since the temperature in the case of controlling to a proper temperature is set in accordance with the temperature of the magnetic induction heating fixing device after a predetermined time has passed since the conveyed recording material passed through the magnetic induction heating fixing device,
The temperature of the fixing device at the time of fixing can be controlled with high accuracy to reduce power consumption and prolong the life of the apparatus.

[Brief description of drawings]

FIG. 1 is a diagram showing a timing chart and temperature change of magnetic induction heating fixing device control in a first embodiment of the present invention.

FIG. 2 is a diagram showing a heating system of the magnetic induction heating fixing roller in the first embodiment of the present invention.

FIG. 3 is an overall model diagram in which a high frequency converter is connected to the magnetic induction heating coil in the first embodiment of the present invention.

FIG. 4 is a flowchart of a controller unit according to the first embodiment of the present invention.

FIG. 5 is a flowchart of a printer engine unit according to the first embodiment of this invention.

FIG. 6 is a flow chart of “control of a startup magnetic induction heating fixing device” in the first embodiment of the present invention.

FIG. 7 is a flow chart of “start-up magnetic induction heating fixing device control” in the first embodiment of the present invention.

FIG. 8 is a flow chart of “start-up magnetic induction heating fixing device control” in the first embodiment of the present invention.

FIG. 9 is a flow chart of “normal magnetic induction heating fixing device control” in the first embodiment of the present invention.

FIG. 10 is a flowchart of “low temperature magnetic induction heating fixing device control” in the first embodiment of the present invention.

FIG. 11 is a flowchart of control in the second embodiment of the present invention.

FIG. 12 is a diagram showing a timing chart and temperature change of magnetic induction heating fixing device control in the third embodiment of the invention.

FIG. 13 is a diagram showing a timing chart and temperature change of magnetic induction heating fixing device control in the third embodiment of the invention.

FIG. 14 is a diagram showing a timing chart and temperature change of magnetic induction heating fixing device control in the third embodiment of the present invention.

FIG. 15 is a block cross-sectional side view of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 16 is an electrical block diagram of an image forming apparatus according to an exemplary embodiment of the present invention.

[Explanation of symbols]

8 Light receiving element (printing means) 9 BD circuit (printing means) 10 High voltage power supply (printing means) 11 Scanner motor (printing means) 12 Scanner motor driver (printing means) 13 Main motor (printing means) 14 Main motor driver (printing) 18) Paper feed sensor (paper feed detection means) 24 Forward / reverse rotation motor driver (printing means) 25 Forward / reverse rotation motor (printing means) 100 Video controller unit (image processing means and signal processing means) 105 Engine controller (process control) Reference numeral 106 Laser driver (printing means) 107 Laser diode (printing means) 108 Polygon mirror 109 Mirror (printing means) 110 Laser light 111 Primary charger (printing means) 112 Photosensitive drum (photoreceptor) 113 Developing device (printing means) 114 Transfer Charger (Printing Unit) 11 Magnetic induction heating fixing device 117 Magnetic induction heating fixing roller (conductive roller) 118 Pressure roller (fixing device) 1030 High frequency converter (means for applying high frequency current) 1100 to 1105 Field coil 1205 Control IC (means for applying high frequency current) )

Claims (9)

[Claims] 1. An image forming method in which an image is formed using an electrophotographic process by forming and carrying a colored developer particle image on a recording material that is supplied and conveyed, and fixing the colored developer particle image on the recording material by a fixing device. In the apparatus, the fixing device is a conductive roller in which at least one roller of a pair of rollers pressed against each other has a conductive layer, and a field coil and a field coil are provided inside the conductive roller. An image forming device, which is a magnetic induction heating fixing device for performing magnetic induction heating fixing, is provided with an induction magnetic material that is coupled to the generated main magnetic flux, and a means for applying a high frequency current is connected to the field coil. In the apparatus, the magnetic induction heating fixing device is heated to a temperature sufficient to start an image forming operation in response to an image forming start signal, and it is detected that the conveyed recording material has passed through the magnetic induction heating fixing device. In response to the signal, the temperature is controlled to be lower than the temperature required for the image forming operation, and is controlled to a temperature sufficient for entering the image forming operation immediately before the leading edge of the next conveyance recording material reaches the magnetic induction heating fixing device. An image forming apparatus having a control device set to operate. 2. A temperature lower than a temperature required for an image forming operation, which is to be controlled when it is detected that a conveyed recording material has passed through a magnetic induction heating fixing device, is set to a temperature required for a previous image forming operation. The image forming apparatus according to claim 1, wherein the image forming apparatus is set correspondingly. 3. A distance immediately before reaching the magnetic induction heating fixing device when the temperature is controlled to a temperature sufficient to start an image forming operation immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. The image forming apparatus according to claim 1, wherein is set corresponding to the temperature required for the image forming operation. 4. The temperature for controlling the temperature of the conveyed recording material by magnetic induction heating and fixing means when controlling the temperature to a temperature sufficient for starting the image forming operation immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating and fixing device. 2. The temperature is set according to the temperature of the magnetic induction heating fixing device after a predetermined time has passed after passing through the sheet.
The image forming apparatus according to item 1. 5. Image processing means for processing input character or image code data to form image data of the image, and signal processing means for outputting a print start signal after the image data is formed by the image processing means. A latent image is formed by scanning a photoconductor with a laser beam modulated in accordance with the image data formed by the image processing means by a polygon mirror, the latent image is developed, and the developed image is transferred to a recording material. 5. The laser beam printer according to claim 1, further comprising: a printing unit that performs printing, a process control unit that manages the operation of the printing unit, and a paper feed detection unit that detects the supplied recording material. The image forming apparatus according to any one of claims. 6. A fixing device for thermally fixing a colored developer particle image on a recording material to the recording material, wherein at least one roller of a pair of rollers pressed against each other is a conductive roller having a conductive layer, A field coil and an induction magnetic material that couples to the main magnetic flux generated in the field coil are provided inside the conductive roller, and a means for applying a high frequency current is connected to the field coil. In the control device of the magnetic induction heating fixing device for performing the magnetic induction heating fixing, the magnetic induction heating fixing device is heated to a temperature sufficient to start the image forming operation in response to the image forming start signal, In response to the signal that the conveyed recording material has passed through the magnetic induction heating fixing device, the temperature is controlled to be lower than the temperature required for the image forming operation, and the leading edge of the next conveying recording material reaches the magnetic induction heating fixing device. Immediately before A control device for a fixing device, characterized in that the temperature is controlled to be sufficient for starting an image forming operation. 7. A temperature lower than a temperature required for an image forming operation, which is to be controlled when it is detected that a conveyed recording material passes through a magnetic induction heating fixing device, is a temperature required for a previous image forming operation. The fixing device control device according to claim 6, wherein the fixing device is set according to the above. 8. A distance immediately before reaching the magnetic induction heating fixing device when controlling to a temperature sufficient for starting an image forming operation immediately before the leading edge of the next conveyed recording material reaches the magnetic induction heating fixing device. 7. The control device for the fixing device according to claim 6, wherein is set in accordance with the temperature required for the image forming operation. 9. The temperature of the transport recording material is controlled to a temperature sufficient for starting an image forming operation immediately before the leading edge of the next transport recording material reaches the magnetic induction heating fixing device. 7. The fixing device control device according to claim 6, wherein the temperature is set in accordance with the temperature of the magnetic induction heating fixing device after a predetermined time has passed after passing through the fixing device.