JP2003330317A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which restricts energy waste with a simple control-structure and restricts the effect of long idling on a fixing process. <P>SOLUTION: The image forming device has a control means that controls the energization of a heat source in such a manner that a heat roller is rotated and also warming up is carried out by the heat source with a fixing belt kept running, then, the device detects, via a temperature sensor, that the surface temperature of the heat roller has reached a set temperature at which fixing is allowed, thereby stopping the drive of the heat roller and the fixing belt and also starting time measurement by the use of a time measuring means, and if the operation of the fixing process is not executed within a predetermined period of time after the start of the time measurement, a control temperature higher than the set temperature is used as a fresh set temperature in order to control the surface temperature of the heat roller. <P>COPYRIGHT: (C)2004,JPO

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 such as a copying machine or a printer for forming an image by an electrophotographic method, and more particularly to an image forming apparatus having an improved control of heating means.

[0002]

2. Description of the Related Art As shown in FIG. 7, it is wound around a suspension member (hereinafter referred to as suspension roller) including a heating roller 102 containing a heating source 16 composed of a halogen lamp and a first pressure roller 103. The fixing belt 104, and the second pressing roller 105 provided so as to be capable of being pressed and released from the first pressing roller 103 via the fixing belt 104.
And a fixing processing section 10 including a fixing belt. The transfer material P after transfer is sent between the first pressure roller 103 and the second pressure roller 105 via a fixing belt, and pressure is applied by both rollers. An image forming apparatus configured to fix the toner image t on the transfer material P by a heating action is known.

Reference numeral 101 is a fixing processing unit 1 for the transfer material P after transfer.
A guide for leading to 0, 50 is an oil coating cleaning device, and 107 is a temperature equalizing member.

The oil coating cleaning device 50 is
It has a function of applying oil to the fixing belt 104 and cleaning the surface of the fixing belt 104.

The temperature equalizing member 107 is composed of a metal roller, and the fixing belt 104 is wound around the suspension roller.
By contacting the fixing belt, the fixing belt has a function of uniformizing the temperature distribution in the width direction (direction orthogonal to the running direction).

Reference numeral 110 denotes a rotary shaft of the first pressure roller 103, which is not shown in the drawing but is provided with a transmission means such as a gear for transmitting power from a drive source of the apparatus main body.
The suspension roller including the heating roller 102 and the first pressure roller 103 is driven to rotate in the direction of the arrow, and the fixing belt 1
04 is configured to run in the direction of the arrow.

The second pressure roller 105 is released from the pressure contact with the fixing belt 104 during the non-fixing process (idling).

A temperature sensor 18 detects the surface temperature of the heating roller 102. In the image forming apparatus having the fixing processing unit 10 as described above, when the power source provided in the apparatus main body is turned on, the heating source 16 of the heating roller 102 is turned on.
Is energized, and at the same time, warming up is performed while the first pressure roller 103 is driven and rotated to move the fixing belt 104.

The completion of the warming-up is performed via the temperature sensor 18 which is a detecting means, and the first pressure roller 10 is accompanied by the completion of the warming-up.
The driving rotation of No. 3 and the fixing belt 104 are stopped, and thereafter, in the idling state, the ON / OFF operation of the heating source 16 is repeated based on the set temperature.

Completion of warming up is performed by detecting, via the temperature sensor 18, whether or not the surface temperature of the heating roller 102 has reached a set temperature.

However, the image forming apparatus having the fixing processing section 10 having the above-mentioned structure has the following problems.

That is, assuming that the state where there is no fixing processing command continues, heat diffusion occurs via the fixing belt and the like after completion of warming up, and the surface temperature of the first pressure roller 103 also decreases. Resulting in.

With respect to the heating roller 102, the output of the temperature sensor 18 is monitored, and the energization control of the heating source 16 is performed accordingly, so that there is no problem, but the temperatures of the first pressure roller 103 and the fixing belt 104 decrease. Can't deal with.

If the second pressure roller 105 does not include a heating source, this roller cannot be similarly treated.

Furthermore, the longer the idling state, the more the temperature of the first pressure roller 103 decreases.

In such a state, when the image forming process is started and the fixing process is performed, the second pressure roller 105 if not including the transfer material P but the first pressure roller 103 and the heat source. Was also deprived of heat, and as a result,
The problem is that the heat for the fixing process runs short.

The above problems may be fatal when, for example, continuous image formation is requested.

In order to solve such a problem, it is conceivable that the second pressure roller is pressed against the first pressure roller via the fixing belt, and idling is performed, but these related elements are driven. If it is configured to be kept at, energy is wasted and a mechanical load is applied to the fixing belt and the roller.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to suppress waste of energy by a simple control structure and to maintain a long idling state. An object of the present invention is to provide an image forming apparatus capable of suppressing the influence on the fixing process.

[0020]

The objects of the present invention can be achieved by the following constitutional requirements.

(1) A fixing belt wound around a suspension member including a heating roller containing a heating source and a first pressure member, and the first belt pressed against each other via the fixing belt.
In an image forming apparatus configured to feed a transfer material after transfer between a pressure member and a second pressure member to fix the toner image transferred on the transfer material, the heating roller is rotated and The heating roller is warmed up while the fixing belt is running, and the heating roller and the fixing belt are detected by detecting through a temperature sensor that the surface temperature of the heating roller has reached a settable temperature. When the fixing processing operation is not executed within a predetermined time after the start of the time counting, the heating roller is stopped as a new set temperature, and the heating roller is set as a new set temperature. An image forming apparatus provided with a control means for controlling energization of the heating source so as to control the surface temperature of the image forming apparatus.

(2) The image forming apparatus according to (1), wherein the control temperature can be set in a plurality of steps.

(3) The image forming method according to (1), wherein the heating roller is a metal roller having an outer peripheral surface covered with a release layer of conductive PFA and an inner diameter surface subjected to black oxidation treatment. apparatus.

(4) The image forming apparatus according to (1), wherein the first pressure member and the second pressure member are rollers.

(5) A fixing belt wound around a suspension member including a heating roller including a heating source and a first pressing member, and the first fixing member pressed against each other via the fixing belt.
In an image forming apparatus configured to feed a transfer material after transfer between a pressure member and a second pressure member to fix the toner image transferred on the transfer material, the heating roller is rotated and Warming up is performed by the heating source while the fixing belt is running, and it is detected by the first temperature sensor that the surface temperature of the heating roller has reached a set temperature at which fixing can be performed. The fixing belt drive is stopped, and after the warming up, the fixing process operation is not executed, and the output of the second temperature sensor arranged at or near the fixing process section becomes lower than a predetermined value. Is detected, the control temperature higher than the set temperature is set as a new set temperature to control the surface temperature of the heating roller so as to control the surface temperature of the heating roller. An image forming apparatus characterized in that a control means for performing control.

(6) The image forming apparatus according to (5), wherein the control temperature can be set in a plurality of stages.

(7) The image forming method according to (5), wherein the heating roller is a metal roller having an outer peripheral surface covered with a release layer of conductive PFA and an inner diameter surface subjected to black oxidation treatment. apparatus.

(8) The image forming apparatus according to (5), wherein the first pressure member and the second pressure member are rollers.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the structure of a color image forming apparatus. As shown in the figure, the image forming apparatus 1 is
It is called a tandem type color image forming apparatus and includes a plurality of sets of image forming units, a belt-shaped intermediate transfer member, a sheet feeding unit, a conveying unit, a plurality of sets of toner cartridges, a fixing processing unit, a power button, and a start button. It is composed of an operation unit 91 and the like made up of operation means including the.

The image forming unit 9Y for forming a yellow image includes a charging unit 2Y, an exposing unit 3Y, a developing unit 4Y, a transferring unit 7Y, which is arranged around an image carrier (hereinafter referred to as a photoconductor) 1Y. It has a cleaning means 8Y.

The image forming unit 9M for forming a magenta image includes a photoconductor 1M, a charging means 2M, and an exposing means 3.
M, developing device 4M, transfer means 7M, cleaning means 8
Have M.

The image forming unit 9C for forming a cyan image includes a photoconductor 1C, a charging means 2C, an exposing means 3C,
It has a developing device 4C, a transfer means 7C, and a cleaning means 8C.

Image forming unit 9K for forming a black image
Has a photoconductor 1K, a charging unit 2K, an exposure unit 3K, a developing device 4K, a transfer unit 7K, and a cleaning unit 8K.

The intermediate transfer member 6 includes a plurality of rollers 6A, 6A.
It is wound around B and 6C and is rotatably supported.

Image forming units 9Y, 9M, 9C, 9K
The images of the respective colors formed by the transfer means 7Y, 7M, 7C, and 7K are sequentially transferred onto the rotating intermediate transfer member 6 to form a superimposed color image.

The transfer materials P contained in a paper feed cassette 20 which is a paper feed means are fed one by one by a paper feed roller 21, and are conveyed to a transfer area where the transfer means 7A is provided via a registration roller 22. Here, the color image on the intermediate transfer body 6 is secondarily transferred to the transfer material P.

The transfer material P on which the color image is transferred is
The fixing process is performed by the fixing processing unit 10, and the paper is ejected onto a paper ejection tray 26 outside the apparatus by being pinched by a paper ejection roller 25 via the conveyance rollers 23 and 24 which are conveyance means.

The fixing processing section 10 has basically the same structure as the conventional structure shown in FIG. 7, and its details will be described later.

On the other hand, the color image is secondarily transferred onto the transfer material P by the transfer means 7A, and the transfer material P is transferred by the separating means 7B.
The intermediate transfer body 6 after the separation of the
The surface is cleaned by A, and the residual toner is removed here.

The control of the heating source according to the present invention will be described below. FIG. 2 is a schematic diagram showing an enlarged main part for explaining the fixing processing part 10.

The same reference numerals are attached to the same means (members) as those already described. Also,
Since the basic configuration is the same as the configuration shown in FIG. 7 as described above, duplicate description will be omitted.

As shown in the figure, the heating roller 102 is a metal roller whose outer peripheral surface is covered with a release layer of conductive PFA (perfluoroalkoxy resin) and whose inner surface is subjected to black oxidation treatment.

The first pressure roller 103 is a roller composed of an elastic layer made of heat-resistant silicone rubber on the outer peripheral surface of a core metal and conductive PFA on the outer surface thereof.

The second pressure roller 105 is a roller having an elastic layer made of heat resistant silicone rubber on the outer peripheral surface of a cored bar and a release layer made of a thin film of conductive PFA on the outer side surface thereof.

The fixing belt 104 is composed of two layers, an inner layer and an outer layer. The inner layer is a support made of an endless nickel electroformed belt or a polyimide belt. The outer layer is coated with heat resistant silicone rubber. In addition, FPA and PTF on the outside
A release layer made of E may be provided.

Reference numeral 18 is a first temperature sensor, which is means for detecting the surface temperature of the heating roller 102. Reference numeral 19 denotes a second temperature sensor, which is a means for detecting the surface temperature of the fixing belt 104 on the first pressure roller 103.

The second temperature sensor 19 is the fixing belt 10.
The transfer material P of No. 4 is provided outside the image area in order to prevent the transfer surface P from being damaged and affecting the image.

The second temperature sensor 19 detects when the surface temperature of the fixing belt 104 falls below a predetermined value which is a predetermined temperature lower than the set temperature, and the detection output thereof is taken into the control means and the heating source 16 is provided. Reflected in the control of.

The first temperature sensor 18 is the temperature sensor 18 in the case of the flow chart of the first embodiment.
The operation of the fixing processing unit 10, which will be referred to as "," will be described by appropriately incorporating the mechanism of FIG.

After the warming up is completed, when an image forming command is input, the suspension roller is driven and rotated through the transmission means to cause the fixing belt 104 to run.

As the transfer material P onto which the toner image t has been transferred is conveyed to the fixing area via the guide 101, the second pressure roller 105 is moved to transfer the transfer material P via the fixing belt 104. The first pressure roller 103 is pressed and conveyed.

The fixed transfer material P is separated by the curvature of the first pressure roller 103, and the transfer rollers 23, 2
The sheet is discharged onto the sheet discharge tray 26 via No. 4. And
If there is no next image formation command, the idling state is entered.

FIG. 3 is a flow chart for explaining the first embodiment, FIG. 4 is a flow chart for explaining the second embodiment, and FIG. 5 is based on a plurality of control temperatures and set temperatures. Is a graph showing a low predetermined temperature,
FIG. 6 is a block diagram showing the electrical configuration of this embodiment.

As shown in FIG. 6, the control section SE includes a power button 910 for turning on the power of the apparatus main body, a start button 911 for starting copying, a first temperature sensor 18, and a second temperature sensor 19. , A driving source MO and a heating source 16 which receive a control signal through a control unit SE including a CPU based on these detection signals and are operated by the control signal.
And a temperature counter TC which is a control means, a temperature controller TC which is a control means, and a second pressure roller 105 which moves when a fixing process operation is started.

The control section SE has a series of functions such as image data storage means and calculation means by the image reading device, but is not shown. Explanation will be given using these figures.

First Embodiment When the power button 910 is pressed, the power from the drive source MO is transmitted, the suspension roller is driven and rotated, and the fixing belt 104 is run.

At the same time, the heating source 1 of the heating roller 102.
6, the warming up (hereinafter referred to as WU) is performed, and the first control temperature CO (FIG. 5) set in the temperature controller TC is set so that the surface temperature of the heating roller 102 is set to a fixing temperature. (Refer to 180 ° C., for example) (ST1).

Next, when the temperature sensor 18 detects that the temperature reaches the first control temperature CO, the driving of the suspension roller and the fixing belt 104 is stopped and only the energization of the heating source 16 is controlled. Maintained as is,
The process proceeds to the next step, and if not detected, the step is returned to the original (ST2).

Next, the clocking of the clocking counter M is started (ST3). If an image formation command is not input within a predetermined time after the start of timing, the process proceeds to the next step, and if it is input, the suspension roller and the fixing belt 104 are driven, and the fixing processing operation is executed. The fixed transfer material P is discharged onto the discharge tray 26 (ST4).

Next, if the time value measured by the time counter M reaches the first predetermined value (for example, 60 seconds),
If the first predetermined value is not reached, the process returns to ST3 (ST5).

Next, in order to make the control temperature higher than the set temperature (first control temperature) a new set temperature, the setting of the temperature controller TC is changed to the second control temperature C1 (see FIG. 5). , The heating source 16 is controlled to raise the surface temperature of the heating roller 102 (for example, corresponding to 185 ° C.) (ST
6).

Next, the clocking is continued (ST7). After that, if the image formation command is not input, the process proceeds to the next step, and if the input is input, the fixing process operation is started (ST8).

Next, if the time value measured by the time counter M reaches a second predetermined value (for example, 180
Seconds), the process proceeds to the next step, and if the second predetermined value is not reached, the process returns to ST7 (ST9).

Next, the set temperature (second control temperature)
In order to set the higher control temperature to a new set temperature, the temperature is changed to the third control temperature C2 to control the heating source 16 to increase the surface temperature of the heating roller 102 (for example, 190 ° C.).
(ST10).

As described above, in this control, as the time after WU elapses, the control temperature is sequentially changed to C1, C2, and C3 as shown in FIG. 5 to increase the new set temperature. It is structured so that it can be reached. Then, the fixing belt 104 whose temperature has decreased due to heat radiation, the temperature decrease due to the heat being taken away by the first pressure roller 103, etc., should avoid the effects of defective fixing and fluctuations in glossiness that tend to occur at the start of the image forming process. There is.

Regarding the method of measuring the time by the time counter M, in addition to the method described in the first embodiment,
After changing the second control temperature or the third control temperature, the time may be reset and timed again.

The changed control temperatures C1, C2, C3
After execution of the fixing process operation, the temperature is returned to the set temperature at which fixing is possible during WU.

Then, the control temperature of the heating roller 102 can be gradually increased with the lapse of time in the same manner as after the completion of the WU, and the control temperature can be gradually increased. When it is assumed that the temperature of the member is rising, the control temperatures, C1, C2, and C3 may be set lower, respectively, or the setting of the predetermined value of the clock counter M may be increased. good.

By performing the temperature control in which the control conditions are changed according to the operation history in this manner, it is possible to perform control with higher accuracy.

Second Embodiment Similar to ST1 of the first embodiment, the heating roller 102 is heated until the surface temperature of the heating roller 102 reaches a first control temperature CO, which is a fixing temperature (ST20). ).

Next, as in the case of ST2, when the first temperature sensor 18 detects that the first control temperature CO has been reached, the suspension roller and the fixing belt 104 are stopped, and the heating roller 102 is stopped. Heating source 16
The energization control is maintained as it is, and the process proceeds to the next step, and if the above detection is not made, the step is returned to the original (S
T21).

Next, if the image forming command is not input, the process proceeds to the next step, and if the image input command is input, the fixing process operation is started (ST22).

Next, if the second temperature sensor 19 detects that the temperature is lower than a predetermined value T ₁ (see FIG. 5) which is a predetermined temperature lower than the set temperature, the process proceeds to the next step, If not detected, step S
Return to T22 (ST23).

Next, in order to make the control temperature higher than the set temperature a new set temperature, the temperature is changed to the second control temperature C1 and the heating source 16 is energized to control the heating roller 102.
The surface temperature of is increased (ST24).

Next, if the image formation command is not input, the process proceeds to the next step, and if the input is input, the fixing process operation is started (ST25).

The _second point is that the temperature is lower than the set temperature to a predetermined value T ₂ which is a lower predetermined temperature.
If the temperature sensor 19 detects it, it will progress to the following step, and if not detected, it will return to ST25 (ST2.
6).

Next, in order to set the control temperature higher than the set temperature to a new set temperature, the third control temperature C
The temperature is changed to 2, and the heating source 16 is energized to increase the surface temperature of the heating roller 102 to a higher temperature (for example, 190 ° C.) (ST27).

In the following order, the second temperature sensor 19
When the detection output of the heating roller 102 reaches the predetermined values T ₁ , T ₂ , and T ₃ that reach the predetermined temperature, the control temperature of the heating roller 102 is changed to C 1, C 2.
The control temperature is changed to a high control temperature of 2 and C3 so that the heating source 16 is energized and the surface temperature of the heating roller 102 is raised.

In addition, the curves of FIG. 5 and T ₁ , T ₂ , T ₃
· · T _n are different in either disposed where the second temperature sensor.

Also in the case of the second embodiment,
When the execution of the fixing process operation is started, the temperature of the fixing belt 104, the transfer material P, the first pressure roller 103, and the second pressure roller which have decreased in temperature due to the stoppage of the driving of the suspension roller and the fixing belt at the completion of WU It is configured so that problems such as defective fixing and fluctuation of glossiness during fixing processing due to heat removal of the roller 105 can be suppressed.

In addition to the above, the second pressure roller 105 may include a heating source so that the surface temperature of the second pressure roller 105 can be increased and a temperature sensor is provided to provide the temperature sensor. When the energization control of the heating source is performed via the sensor, the temperature decrease of the second pressure roller 105 does not occur, so that the temperature decrease of the fixing belt 104 and the first pressure roller 103 is mainly compensated. It will be.

Here, the second temperature sensor 19 is arranged so as to detect the surface temperature of the fixing belt 104 on the first pressure roller 103, but the second temperature sensor 19 does not include the heating source.
The pressure roller 105 and the first pressure roller 103 without the fixing belt 104, a part of the casing of the fixing processing unit 10, and the like may be appropriately disposed in the vicinity thereof.

With the simple control configuration as in the present invention, it is possible to provide the image forming apparatus which suppresses the waste of energy and does not affect the fixing process even if the idling state continues for a long time.

According to the present invention, the fixing belt is wound around a suspension member composed of one roller and a small semi-cylindrical pressure member to which the other is fixed, or a protrusion provided on the roller is formed on the surface of the fixing belt. The present invention is also applicable to an image forming apparatus in which the second pressure roller is pressure-bonded to the pressure member and the fixing process of the transfer material P is performed in a configuration in which the fixing belt is wound around by fitting with the hole. The term "warming up" as used in the present invention includes the case where the fixing processing operation can be performed after the fixing operation or the fixing processing operation can be performed after the fixing operation is recovered. .

[0086]

As described above, according to the present invention, it is possible to provide an image forming apparatus which suppresses the waste of energy by a simple control structure and does not affect the fixing process even if the idling state continues for a long time.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a color image forming apparatus.

FIG. 2 is a schematic view showing an enlarged main part for explaining a fixing processing part.

FIG. 3 is a flowchart for explaining the first embodiment.

FIG. 4 is a flowchart for explaining the second embodiment.

FIG. 5 is a graph showing a plurality of control temperatures and a predetermined temperature lower than a set temperature.

FIG. 6 is a block diagram showing an electrical configuration of the present embodiment.

FIG. 7 is a diagram of a fixing processing unit of a known image forming apparatus.

[Explanation of symbols]

1 the image forming apparatus 10 fixing process unit 16 heating source 18 first temperature sensor 19 second temperature sensor M time counter SE controller TC temperature controller MO drive source CO, C1, C2, C3, T 1, T 2, T 3 Control temperature and predetermined temperature 102 Heating roller 103 First pressure roller 104 Fixing belt 105 Second pressure roller 910 Power button

Claims (8)

[Claims] 1. A heating roller including a heating source and a first heating roller.
A fixing belt wound around a suspension member including a pressure member,
A transfer material after transfer is sent between the first pressure member and the second pressure member that are pressed against each other via the fixing belt, and the toner image transferred onto the transfer material is fixed. In the image forming apparatus, the temperature sensor indicates that the surface temperature of the heating roller has reached a set temperature at which fixing can be performed by performing warming up by the heating source while rotating the heating roller and running the fixing belt. The heating roller and the fixing belt are stopped by detecting through the time, and the time measurement by the time measuring means is started, and when the fixing processing operation is not executed within a predetermined time after the start of the time measurement, the set temperature is set. The control means for controlling the energization of the heating source is provided to control the surface temperature of the heating roller with a higher control temperature as a new set temperature. An image forming apparatus characterized by. 2. The image forming apparatus according to claim 1, wherein the control temperature can be set in multiple stages. 3. The heating roller has a conductive PF on its outer peripheral surface.
The image forming apparatus according to claim 1, wherein the image forming apparatus is a metal roller which is covered with a release layer A and whose inner diameter surface is subjected to black oxidation treatment. 4. The image forming apparatus according to claim 1, wherein the first pressure member and the second pressure member are rollers. 5. A heating roller including a heating source, and a first roller.
A fixing belt wound around a suspension member including a pressure member,
A transfer material after transfer is sent between the first pressure member and the second pressure member that are pressed against each other via the fixing belt, and the toner image transferred onto the transfer material is fixed. In the image forming apparatus described above, the heating source is warmed up while the heating roller is rotated and the fixing belt is running, and the surface temperature of the heating roller reaches a set temperature at which fixing is possible. By detecting through a temperature sensor, the driving of the heating roller and the fixing belt is stopped, and when the fixing processing operation is not executed after the warming-up is completed, and when the fixing processing unit or the vicinity thereof is disposed. 2 When it is detected that the output of the temperature sensor is lower than the predetermined value, the control temperature higher than the set temperature is set as the new set temperature. An image forming apparatus characterized in that a control means for performing energization control of the heat source to control the surface temperature of the heating roller. 6. The image forming apparatus according to claim 5, wherein the control temperature can be set in multiple steps. 7. The heating roller has a conductive PF on its outer peripheral surface.
The image forming apparatus according to claim 5, wherein the image forming apparatus is a metal roller which is covered with the release layer A and whose inner diameter surface is subjected to black oxidation treatment. 8. The image forming apparatus according to claim 5, wherein the first pressure member and the second pressure member are rollers.