JP2002023556A - Heating device and image forming device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device which can optimize the length of the time between successively fixed preceding and following recording media and prevent image disturbance, etc., due to tan overrise in the temperature in a paper non-passing region of a nip, and to provide an image forming device with the heating device. SOLUTION: The length of the time from the nip passage of the preceding recording medium between the two successively fixed recording media to the nip entry of the following recording medium is extended until the temperature of the paper non-passing region of the nip falls below 150 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nip formed by a pressurizing member pressing a recording medium carrying an image onto a heating member. The present invention relates to a heating device to be applied and an image forming apparatus including the heating device.

[0002]

2. Description of the Related Art Conventionally, as a heating device represented by a heat fixing device, a contact heating system such as a heat roller system and a film heating system has been widely used. In such a heating device, a current is passed through a halogen lamp or a heating resistor as a heating element to generate heat, and a heating process is performed on a toner image as an image on a recording medium via a roller or a film as a film member. ing. Therefore, conventionally, a method of forming a heating element by providing a pattern of a resistance heating element on a substrate such as a ceramic and heating the recording medium as a heated object via a thin film has been proposed in Japanese Patent Application Laid-Open No. H10-163,873. 63-3131
82. In controlling the heating element,
As a countermeasure against the temperature rise in the non-sheet passing area, a method of always suppressing the heat generation between the sheets even when the heating body is cooled is disclosed in
49103.

FIG. 11 is a schematic sectional view of a film heating and fixing device as an example of a conventional heating device.

As shown in FIG. 11, a film heating and fixing apparatus includes a heating member 103, a film 102 as an endless and heat-resistant film member, and a pressure roller 10 as a pressure member.
4 is provided.

[0005] The film 102 is externally fitted to a heating element support 101 which includes a heating element 103 and is also a guide member for externally fitting the film 102. The inner peripheral length of the film 102 is, for example, 3 mm longer than the outer peripheral length of the heater support 101.
Therefore, it is loosely fitted to the heater support 101 with a margin of the circumference.

The film thickness of the film 102 is 100 μm or less, preferably 50 μm or less and 20 μm or less, in order to reduce the heat capacity and improve the quick start property.
A single layer of PTFE, PFA, FEP having the above heat resistance,
Or polyimide, polyamide imide, PEEK, PE
A composite layer film in which PTFE, PFA, FEP, or the like is coated on the outer peripheral surface of S, PPS, or the like can be used. In this example, a polyimide film having an outer peripheral surface coated with PTFE is used.

The heating element 103 is formed by coating an electric resistance material such as Ag / Pd (silver palladium) on a substrate surface made of alumina or the like by screen printing or the like to a thickness of about 10 μm and a width of 1 to 3 mm. Is coated with glass, fluororesin, or the like as a protective layer 107.

The pressure roller 104 is a rotating body that drives the film 102 by forming a nip N by pressing against the heating body 103 via the film 102. The driving force is transmitted to the end of the cored bar 104-A by a driving means (not shown), and is driven to rotate.

In controlling the temperature of the heating element 103, the output of the thermistor 105 provided on the heating element 103 is A / A
D-converted and taken into the CPU 110, and based on the information, the CPU 110 controls the power supplied to the heating element 103 by controlling the phase and the wave number of the AC voltage supplied to the heating element 103 by the triac 111. ing.

FIG. 12 is a diagram showing a transition of the temperature of the heater 3 in the conventional power control of the heater 103.

Conventionally, as shown in FIG. 12, when the heating device main body is not operated for 5 to 6 hours,
Is almost cooled to room temperature. Heating body 103 at that time
Shows TA [° C.]. This TA is the detected temperature of the thermistor 105 that is in contact with the heating element 103, and the position of the thermistor 105 in the direction perpendicular to the transport direction of the recording medium is defined as a range that falls within the width of the minimum size of the printable recording medium. Has become.

In such a heating device, when printing is started, the temperature of the heating body 103 starts to rise, and the detected temperature of the thermistor 105 changes to Tb, Tc ‥ [° C.] with the rise in temperature. Immediately before the recording medium P enters the nip N, the temperature of the heating element 103 rises to a fixing temperature Td necessary for permanently fixing the unfixed image.

Here, input voltage AC 120 V, paper type CO
A case where printing is performed in an M10 envelope (width 105 mm, length 241 mm), process speed 80 mm / sec, room temperature 23 ° C./50% environment will be described.

For example, in a heating apparatus in which the maximum size of a printable recording medium is 220 mm wide, when the COM10 envelope is passed, the ratio of the paper passing area to the non-paper passing area is about 1: 1. Becomes FIG. 13 shows the temperature states of the sheet passing area and the non-sheet passing area of the heating element 103 in the nip when the sheet is passed at that time.

In this case, as shown in FIG. 13, since the COM10 envelope passes through the paper passing area, the temperature of the heating body support 101 and the pressure roller 104 supporting the heating body 103 does not rise so much. In the non-sheet passing area through which no paper passes, the temperature rises because there is no place for heat to escape. If the paper is passed (printed) in this state, the heater support and the pressure roller may be destroyed. By changing the temperature, or by changing the temperature at which the image is fixed, the occurrence of destruction is prevented. In this example, the paper passing ratio of the recording medium is about 1: 1. However, the same phenomenon occurs not only when the paper passing ratio is 1: 1 but also when the paper passing ratio is 1: 1.2 or 1: 1. : Even at 0.2 or the like, there is a possibility that the same occurs.

Here, among the commonly known standard paper sizes, the present embodiment provides legal,
There are letter, A4, B5, envelope, postcard, COM10 envelope size and the like. Among these, B5, postcard, COM10, etc. are located in a relatively narrow area. The characteristics of these recording media are that the paper width is narrow and the length of the recording medium is correspondingly short.

The type of recording medium, paper width, length, and the tendency are as follows: Legal width: 216 mm Length: 356 mm Letter width: 216 mm Length: 279 mm A4 Width: 210 mm Length: 297 mm B5 Width: 182 mm Length: 257 mm Envelope (B5 size) Width: 174 mm Length: 250 mm COM10 Envelope Width 105 mm Length: 241 mm Postcard Width: 100 mm Length: 148 mm 3 × 5 inch Width: 76 mm Length: 127 mm

As can be seen from the above list, when the width of the recording medium is relatively narrow and the size is B5 or less, the length of the recording medium is 257 mm or less. As described above, the width and length of the recording medium relatively correspond to the case where the width of the recording medium is small, and the length is short for the wide recording medium. Is what it is. In this example, the standard paper is described, and nothing is described about a case where the user cuts the standard paper into an irregular shape. Therefore, in this example, the following description will be made with the width of the recording medium (∝the length of the recording medium) for convenience.

In the case of passing such a short paper type, there is a possibility that an excessive temperature rise in the non-sheet passing area occurs in many types of paper. In order to reduce this phenomenon, in addition to the thermistor 105 (referred to as first temperature detecting means) shown in FIG. 11, a second temperature detecting means for monitoring the temperature of the non-sheet passing area in the non-sheet passing area is separately provided. Must be provided.

Conventionally, in a heating apparatus having a first temperature detecting means and a second temperature detecting means, the second temperature detecting means is arranged in a non-sheet passing area (outside the minimum recording medium width), and the non-sheet passing area is excessively heated. The operation (heating condition) of the image forming apparatus is changed when the temperature is high.

As the heat treatment conditions, for example, as shown in FIG. 14, when the second temperature detecting means has reached a certain temperature (in this conventional example, when the second temperature detecting means detects 260 ° C.) ), A method such as "changing the number of sheets passed through the recording medium per unit time" or a method such as "changing the temperature at which the fixing is performed" is used. I'm taking a countermeasure.

As another means, the length of the recording medium passing through the nip in the transport direction is measured by a sensor or the like. , Or a method of "changing the temperature at which fixing is performed".

Here, a description will be given of the drive control between two consecutive recording media (the preceding recording medium and the succeeding recording medium following the preceding recording medium) in the heating device.

Conventionally, as shown in FIG. 15A, no limitation is imposed despite the fact that the non-sheet-passing area of the heating element is excessively heated after the printing (fixing process) of the advance recording medium is completed. 15B, the printing of the subsequent recording medium is accepted and the printing is started, and as shown in FIG. 15B, the printing of the subsequent recording medium is accepted after the printing of the preceding recording medium is completed, but the printing is not started immediately. 2. Description of the Related Art A heating device is known which uses a control for extending a time for rotating a film member and a pressure member (hereinafter, referred to as “post-rotation”) until printing of a subsequent recording medium is started based on the size (mainly, length) of the preceding recording medium. I have.

For reference, FIG. 1 is a table showing the width and length of the paper passing area, the width of the non-paper passing area, the temperature rise temperature of the non-paper passing area when plain paper is passed, the offset situation, and the slip situation for each paper type.
6 is shown.

For example, as shown in FIG.
In the case of an envelope, the length of the COM10 envelope is 241
mm, the width is 105 mm, and the width of the non-sheet passing area is 220 mm because the width of the sheet passing area in the conventional example is 220 mm.
-105 = 115 mm.

In FIG. 16, when the COM10 envelope is continuously passed through the nip, the temperature of the non-sheet passing area is 230 ° C.
Heat up to It is shown that plain paper is passed immediately after this. Furthermore, as a problem of the image at that time,
This indicates that there was an offset and NG, NG because a slip condition between the film and the recording medium also occurred, and NG because a slip also occurred between the pressure roller and the recording medium. The limit of the temperature rise temperature in the non-sheet passing area (safety zone temperature where no image problem occurs) is 180 ° C. or less.

According to FIG. 16, in the case of A4 plain paper, since the temperature of the non-sheet passing area is as low as 140 ° C., there is no image disturbance due to the temperature rise in the non-sheet passing area. Understand.

[0029]

However, in the above-mentioned conventional heating apparatus, the number of sheets passed through the recording medium per unit time is reduced, or the temperature at which the fixing is performed is lowered. However, even if the post-rotation time is extended, the temperature of the non-sheet-passing area slightly increases, and if a medium-size recording medium is passed in this state, it will fall into the non-sheet-passing area. There is a possibility that the printed image is over-fixed in the fixing unit and offset occurs. After that, when the plain paper size is passed as it is, the temperature of the non-sheet-passing area temperature raising section falls and the temperature distribution of the pressure roller becomes uniform, so that offset does not occur. At present, there is a need to improve the problem of the offset immediately after paper passing as described above.

Further, if the heating device is in an abnormally high temperature, other adverse effects will occur. For example, in the state where the medium-size recording medium is passed as described above while the temperature is raised, if the print image size on the recording medium is large (shaded area) as shown in FIG. However, as shown in FIG. 17B, in the case of a printed image in a small range (shaded portion), the area of the contact surface (adhesive force) between the recording medium and the fixing film via the toner is small. Since the amount decreases, the conveying force of the recording medium by the fixing film decreases, and the fixing film and the recording medium slip. This phenomenon is likely to occur in a place where the temperature rises, the fixing nip in the place where the temperature rises becomes larger than usual, and the conveying force differs between the paper passing area and the non-paper passing area. The cause may be that the pressure roller expands to increase the resistance between the fixing film and the heating element.

On the other hand, although this is also based on a special printed image, in the case of a black single-sided image, a problem arises when the printed image size on the recording medium is large as shown in FIG. This may cause no problem in the case of a print image of a small range as shown in FIG. Such a phenomenon is mainly a phenomenon in which the pressure roller and the recording medium slide, and the mechanism is that when the recording medium is passed through the nip in a state where the temperature rise is larger than a certain level,
Since the heating is performed instantaneously in the high temperature part of the fixing part, water vapor of the recording medium and toner is generated between the fixing film and the recording medium and between the recording medium and the pressure roller, and a thin water vapor film is formed. It happens to be.

Therefore, according to the present invention, the length of the inter-paper time between the first recording medium continuously subjected to fixing and the succeeding recording medium following the first recording medium can be optimized, and the nip can be reduced. It is an object of the present invention to provide a heating device capable of preventing an image disturbance or the like due to excessive temperature rise in a non-sheet passing area and an image forming apparatus including the heating device.

[0033]

According to the present invention, an object of the present invention is to provide a heating element for heating a recording medium carrying an image by being supplied from a power source, and an endless belt-shaped rotating member which slides on the heating element. A flexible film member and a rotatable pressurizing member that is pressed against the heating member via the film member, and the recording medium is formed by a nip formed by pressing the pressing member against the heating member. A heating device that performs a heating process while pressing and holding the film member and the pressurizing body while pressing the same; a first temperature detecting unit that detects a temperature of the heating body in a paper passing region of the nip; and a non-paper passing region of the nip. A second temperature detecting means for detecting a temperature of the heating element in the heating apparatus, and controlling a power supply from a power supply to the heating element such that a sheet passing area temperature detected by the first temperature detecting means is maintained within a first predetermined temperature range. Possible system Means, and the length of the inter-paper time from the passage of the nip of the first recording medium to the nip of the subsequent recording medium following the preceding recording medium in the two recording media that are continuously subjected to fixing, This is achieved by the first invention in which the non-sheet passing area temperature can be extended until the temperature becomes equal to or lower than the second predetermined temperature.

Further, according to the present application, the above object is achieved in the first aspect, in which the film member and the pressurizing member are disposed in the non-sheet passing area detected by the second temperature detecting means after the nip of the starting recording medium. The present invention is also achieved by the second invention in which the nip of the subsequent recording medium can be entered after the temperature becomes equal to or lower than the second predetermined temperature.

Further, according to the present application, the above object is achieved in the first invention or the second invention, wherein the film member and the pressure member are detected by the second temperature detecting means after passing through the nip of the starting recording medium. The present invention is also achieved by the third invention in which the nip of the subsequent recording medium can be entered after the temperature of the non-sheet passing area becomes 180 ° C. or less.

According to the present application, the above object is achieved in the first invention or the second invention, wherein the film member and the pressurizing member are connected to the second recording medium within an upper limit of 60 seconds after passing through the nip of the first recording medium. This is also achieved by the fourth invention in which nip rush is possible.

Further, according to the present application, the above object is achieved according to any one of the first to fourth inventions, wherein the film member and the pressurizing member are configured to be driven to rotate during the inter-paper time. This is also achieved by the fifth invention.

According to the present application, the above object is achieved in any one of the first to fifth inventions in that the extension of the inter-paper time is such that the length of the advance recording medium in the transport direction is a predetermined length. The present invention is also achieved by the sixth invention in which the setting is made in the following case.

Further, according to the present application, the above object is achieved according to any one of the first to sixth inventions, wherein the length of the sheet interval is increased by 270 mm in the transport direction of the starting recording medium.
The present invention is also achieved by a seventh invention in which the setting is made in the following case.

According to the present application, the above object is achieved according to any one of the first to seventh inventions, wherein the inter-paper time is extended by feeding the advance recording medium to the nip at least by manual insertion. The present invention is also achieved by an eighth invention that is made when the above is done.

Further, according to the present application, the above object is achieved by any one of the first to eighth aspects of the present invention, further comprising a cooling means capable of cooling at least a non-sheet passing area of the heating element, The present invention is also achieved by the ninth invention in which the cooling effect is set to be longer than that in the fixing process when the inter-sheet time is extended.

Further, according to the present application, the above object is achieved in any one of the first to ninth aspects in that the film member and the pressure member are provided with a longer inter-sheet time than in the fixing process. This is also achieved by the tenth invention in which the rotation speed is set to be increased.

Further, according to the present application, an object of the present invention is to provide an image forming apparatus for recording an image formed by a series of image forming processes on a recording medium, comprising the heating device of the first invention. This is also achieved by one invention.

According to the present application, the above object is achieved according to the eleventh aspect, in which the film member and the pressurized member are detected by the second temperature detecting means after passing through the nip of the preceding recording medium. The present invention is also achieved by a twelfth invention in which the nip of a subsequent recording medium can be entered after the area temperature has become equal to or lower than the second predetermined temperature.

Further, according to the present application, the above object is achieved in the eleventh invention or the twelfth invention in that, after the film member and the pressure body pass through the nip of the starting recording medium, the film member and the pressing body are moved by the second temperature detecting means. The present invention is also achieved by the thirteenth invention in which the nip of the subsequent recording medium can be entered after the detected non-sheet passing area temperature becomes 180 ° C. or less.

According to the present application, the above object is achieved in the eleventh invention or the twelfth invention, in which the film member and the pressing body are kept at an upper limit of 60 seconds after passing through the nip of the starting recording medium.
The present invention is also achieved by the fourteenth invention in which the nip of the subsequent recording medium can be entered within the following range.

Further, according to the present application, the above object is achieved according to any one of the eleventh to fourteenth inventions, in which the film member and the pressing body are driven to rotate during the sheet interval. The present invention is also achieved by the fifteenth aspect of the invention.

According to the present application, the above object is achieved according to any one of the eleventh to fifteenth inventions, wherein the inter-sheet time is extended by a predetermined length in the transport direction of the advance recording medium. The invention is also achieved by a sixteenth invention in which the setting is made when the length is shorter than the length.

Further, according to the present application, the above object is achieved according to any one of the eleventh to sixteenth inventions, wherein the inter-sheet time is extended by a length of 270 in the transport direction of the advance recording medium.
This is also achieved by the seventeenth invention in which the setting is made when the distance is equal to or less than mm.

Further, according to the present application, the above object is achieved in any one of the eleventh to seventeenth aspects of the present invention in that the inter-sheet time is extended by at least manual feeding of the starting recording medium to the nip. The present invention is also achieved by an eighteenth invention that is made when performed.

Further, according to the present application, the above object is provided in any one of the eleventh invention to the eighteenth invention, wherein a cooling means capable of cooling at least a non-sheet passing area of the heating body is provided,
The cooling means is also achieved by a nineteenth invention in which the cooling effect is set so as to increase the cooling effect when the inter-sheet time is extended as compared with the time of the fixing process.

Further, according to the present application, the above object is achieved in any one of the eleventh to nineteenth inventions, wherein the film member and the pressurizing body are fixed at the time of fixing processing when the inter-paper time is extended. The present invention is also achieved by a twentieth invention in which the rotation speed is set to be increased more than the rotation speed.

That is, in the first invention according to the present application, the length of the sheet interval is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature.

In the second invention according to the present application, the length of the inter-paper time is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area falls below the second predetermined temperature. .

Further, in the third invention according to the present application, the length of the inter-sheet time is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area becomes 180 ° C. or less.

Further, in the fourth invention according to the present application, the length of the inter-paper time is extended so that the succeeding recording medium enters the nip within an upper limit of 60 sec after the preceding recording medium passes through the nip.

Further, in the fifth invention according to the present application, the length of the inter-sheet time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. The film member and the pressing body are driven to rotate.

According to the sixth aspect of the present invention, when the length of the advance recording medium in the transport direction is equal to or less than a predetermined length, the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature. Extend the length of the inter-paper time until

Further, according to the seventh invention of the present application, when the length of the advance recording medium in the transport direction is 270 mm or less, the temperature of the non-sheet passing area becomes lower than the second predetermined temperature. Extend the length of the inter-paper time.

In the eighth invention according to the present application, the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature when the advance recording medium is fed to the nip by at least manual feeding. Extend the length of time between papers.

Further, in the ninth invention according to the present application, the length of the inter-sheet time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature, and at the same time, The effect of cooling the heating element by the cooling means is increased from that at the time of the fixing process.

In the tenth invention according to the present application, the length of the inter-paper time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. The rotation speeds of the film member and the pressing body are increased from those during the fixing process.

Further, in the eleventh invention according to the present application, the length of the sheet interval is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature.

In the twelfth invention according to the present application, the length of the sheet interval is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area falls below the second predetermined temperature. I do.

Further, in the thirteenth invention according to the present application, the length of the inter-sheet time is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area becomes 180 ° C. or less.

Further, in the fourteenth invention according to the present application, the length of the sheet interval is extended so that the succeeding recording medium enters the nip within an upper limit of 60 seconds after passing through the nip of the preceding recording medium.

Further, in the fifteenth invention according to the present application, the length of the inter-paper time is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature. The film member and the pressing body are driven to rotate.

In the sixteenth invention according to the present application, when the length of the advance recording medium in the transport direction is equal to or less than the predetermined length, the temperature of the non-sheet passing area is equal to or lower than the second predetermined temperature. Extend the time between papers until

Further, according to the seventeenth aspect of the present invention, when the length of the advance recording medium in the transport direction is 270 mm or less, the temperature of the non-sheet passing area becomes lower than the second predetermined temperature. Extend the length of time between papers.

According to the eighteenth aspect of the present invention, when the advance recording medium is fed into the nip by at least manual feeding, the temperature of the non-sheet passing area falls below the second predetermined temperature. Extend the length of the inter-paper time until

Further, in the nineteenth invention according to the present application, the length of the inter-paper time is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature, and at the same time, In addition, the effect of cooling the heating element by the cooling means is increased more than during the fixing process.

In the twentieth invention according to the present application, the length of the inter-paper time is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature, and at the same time, Then, the rotation speeds of the film member and the pressure member are increased from those during the fixing process.

[0073]

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.

FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a laser printer 21 (hereinafter, abbreviated as a printer 21) as a preferred example of the image forming apparatus according to the present embodiment.

The printer 21 is an image forming apparatus that records an image corresponding to information provided from an output device (not shown) such as a host computer provided outside the main body of the printer 21 on the recording medium P.

As shown in FIG. 1, the printer 21 has a drum-shaped latent image carrier 22 for carrying an electrostatic latent image on the outer peripheral surface in accordance with information provided from the output device, and develops the electrostatic latent image. Developing device 23 for visualizing a developer image with a developer, a transfer roller 24 for transferring the developer image as an unfixed image to recording medium P, and a heating device for performing a fixing process on the transferred recording medium P A fixing device 25 is provided.

In the present embodiment, the latent image carrier 22 and the developing device 23 are generally controlled by an engine controller 26 provided in the main body of the printer 21. I have.

The surface layer of the latent image carrier 22 is a photoconductive layer mainly composed of an organic photoreceptor, and receives a driving force from a driving mechanism (not shown) provided in the main body of the printer 21. Thereby, it is driven to rotate clockwise.

That is, the outer peripheral surface of the latent image carrier 22 is charged to a predetermined potential distribution by the primary charging roller 27, and then the laser La blinked from the exposure device 44 according to the information provided from the output device is applied to the mirror 28 or the like. , An electrostatic latent image corresponding to the provided information is formed.

The transfer roller 24 is rotatably supported at a position in contact with or in proximity to the latent image carrier 22, so that a transfer nip portion T for performing a transfer process on the recording medium P is provided.
N is formed between the latent image carrier 22 and N.

That is, in the present embodiment, the transfer roller 24 charges the recording medium P that has reached the transfer nip portion TN to a polarity opposite to that of the developer image on the outer peripheral surface of the latent image carrier 22. An electric interaction is caused between the developer image and the recording medium P, so that the developer image is carried on the recording medium P as an unfixed image.

In this embodiment, the recording medium P
First, the feeding direction of the recording medium P from the paper feeding roller 30 by the paper feeding roller 30 from the cassette 29 detachably supported by the main body of the printer 21 or by the paper feeding from a manual feed unit (not shown). The paper is fed to a transport roller 31 that is rotatably supported at an upstream position.

Next, the recording medium P that has reached the transport roller 31 is transported by the transport roller 31 from the transport roller 31 to a paper feed sensor 32 disposed at a position upstream of the transport direction of the recording medium P.

The feed sensor 32 moves the recording medium P to the transfer nip portion TN so that the leading end of the unfixed image carrying portion on the recording medium P and the leading end of the image forming portion on the outer peripheral surface of the latent image carrier 22 are synchronized. Will be transported to

The recording medium P carrying the unfixed image is conveyed to the fixing device 25 and heated and pressed by the fixing device 25 to fix the unfixed image on the recording medium P.
The paper is discharged onto the paper discharge tray 14 by the paper discharge rollers 33.

FIG. 2 is a schematic sectional view of a film heat fixing device as an example of the fixing device 25.

As shown in FIG. 2, the fixing device 25 includes a heating element 3, a film 2 as an endless and heat-resistant film member, a pressing roller 4 as a pressing element, and a first temperature detecting means as a first temperature detecting means. The device includes a thermistor 5a and a second thermistor 5b as a second temperature detecting means.

The film 2 including the heating element 3
Is externally fitted to the heater support 1, which is also a guide member for externally fitting. This film 2 has an inner peripheral length of the heating body support 1.
Is, for example, about 3 mm larger than the outer peripheral length of the heating element support 1, and is loosely fitted to the heating element support 1 with a margin of the peripheral length.

The film 2 has a heat resistance of 100 μm or less, preferably 50 μm or less and 20 μm or more and has a heat-resistant single layer of PTFE, PFA or FEP in order to reduce the heat capacity and improve the quick start property. Or polyimide, polyamide imide, PEEK, PES,
A composite layer film in which the outer peripheral surface of PPS or the like is coated with PTFE, PFA, FEP, or the like can be used. In the present embodiment, a polyimide film whose outer peripheral surface is coated with PTFE is used.

The heating element 3 is formed by coating an electric resistance material such as Ag / Pd (silver palladium) on a substrate surface made of alumina or the like by screen printing or the like to a thickness of about 10 μm and a width of 1 to 3 mm. Is coated with glass, fluororesin or the like as a protective layer 7.

The pressure roller 4 is a rotating body that drives the film 2 by forming a nip N by pressing against the heating element 3 via the film 2. The driving force is transmitted to the end of the metal core 4-A by a driving means (not shown) and is driven to rotate.

In controlling the temperature of the heating element 3, the heating element 3
The outputs of the first thermistor 5a and the second thermistor 5b provided above are A / D converted and taken into the CPU 10,
Based on the information, the CPU 10 controls the power supplied to the heating element 3 by controlling the phase and wave number of the AC voltage applied to the heating element 3 by the triac 11.

Here, regarding the control operation of the conventional fixing device during the continuous fixing process, one state in the morning (a state immediately after the power is turned on).
An example in which the COM10 envelope is continuously passed through the nip from the nip will be described.

FIG. 4 is a diagram showing the transition of the detected temperature by the first thermistor and the second thermistor in the above case. FIG. 5 is a graph showing the temperature of the pressure roller in the paper passing area and the non-paper passing area in the above case. It is a figure showing a change.

As shown in FIG. 5, the temperature of the pressure roller in the sheet passing area decreases during the sheet passing, but increases between the sheets. This indicates that the amount of heat of the heating element is insulated by the recording medium during the paper passing, so that heat is not easily transmitted. On the other hand, in the non-paper area,
The amount of heat of the heating element and the pressure roller rises during paper passing because there is no recording medium passing therethrough.

As shown in FIG. 4, the temperature detected by the first thermistor is the same as the control temperature of the heater by the CPU. On the other hand, the temperature detected by the second thermistor rises during paper passing without releasing heat due to the passage of the nip of the recording medium because the second thermistor detects the temperature of the heating element in the non-paper passing area. . Conventionally, when the non-sheet passing area is near the upper limit of the heat-resistant temperature, the amount of paper passing through the recording medium per unit time is reduced, and the control is performed to lower the temperature between sheets to prevent the fixing device from being destroyed. However, when a recording medium such as a COM10 envelope is continuously passed through the nip, the pressure roller (heat-resistant 235 ° C.), the second thermistor, and the film guide (heat-resistant) in the non-sheet-passing area are further supported. 275 ° C.) may rise to a temperature near the limit of the heat-resistant temperature.

Next, a case where a medium-sized recording medium is passed through the nip in the above-described temperature rising state will be described.

4 and 5, a broken line A indicates a state immediately after sheet passing, and a broken line B indicates a point in time when the temperature state of non-sheet passing becomes good. In the figure, the temperatures of the second thermistor and the pressure roller immediately after B are 150 ° C. and 140 ° C., respectively.

Looking at the printed image at this time, a broken line A
Immediately after, the image on the recording medium passed through is disturbed. In the printed image at this time, as shown in FIG. 6, the image at the leading end of the image is dragged toward the descending end. this is,
This is caused by an increase in the resistance (α) of the film and the heating element at the end due to an increase in the temperature of the non-sheet passing area, and a decrease in the driving force (β) of the film by the recording medium due to the narrow printing area of the recording medium. It is a phenomenon. That is, in the force relationship of (α) and (β), (α) was greater because it was larger.

The control used in this embodiment to prevent this phenomenon will be described with reference to the flowchart shown in FIG.

First, the control when the advance recording medium is fed from the cassette 29 will be described with reference to FIG. In the present embodiment, control similar to the control shown in FIG. 14 is also performed, but detailed description is omitted.

FIG. 7B shows that the starting recording medium is the cassette 2
9 indicates the timing at which the subsequent recording medium is fed and passed when the paper is fed from step 9 (hereinafter referred to as cassette sheet feeding). First, as a premise, the condition is that the temperature rise in the non-sheet passing area is difficult to occur because many users feed a relatively large size (plain paper) in the cassette sheet feeding. For this reason, when a signal for feeding the later recording medium comes after the printing is completed, the printing is performed as it is. The paper feed port may be either the cassette 29 or a manual feed unit.

Next, the control when the advance recording medium is fed from the manual feed section will be described with reference to FIG.

FIG. 7A shows the timing at which the subsequent recording medium is fed and passed when the starting recording medium is fed from the manual feed unit (hereinafter referred to as manual feeding). Is what it is. In the case of manual sheet feeding, a small-sized recording medium is mainly passed in many cases. That is, it indicates that there are many recording media in which the temperature rise in the non-sheet passing area as described above occurs. The range of the “small size” is as follows. The length of the B5 size, which causes a problem in FIG. 16, is 257 mm, but the length is 270 mm or less in consideration of the case where the paper is fed obliquely. I do.

First, when the feed signal of the subsequent recording medium comes during the rotation of the film 2 and the pressure roller 4 after the printing of the preceding recording medium is completed (hereinafter referred to as “post-rotation”), the same paper type is used for manual paper feeding. Therefore, the subsequent recording medium is fed from the manual feed slot and printing is performed.
Next, since plain paper is fed in the case of cassette feeding, the above-described problem occurs if the paper is fed while the temperature in the non-sheet passing area is raised as it is. for that reason,
It is necessary to wait until the temperature of the non-sheet passing area falls within the safe area (a temperature at which no problem occurs).

Now, the points of this embodiment will be described.

As a method for this, the temperature is waited for to decrease while the length of the post-rotation is extended. When the second thermistor 5b disposed in the non-sheet passing area falls to 150 ° C. or less which is within the safe range during the post-rotation, the post-rotation is terminated, and the film 2 and the pressure for the next print preparation are pressed. The rotation of the roller 4 (hereinafter referred to as "pre-rotation") is performed, and then the subsequent recording medium is fed, and then printing is started. on the other hand,
If the temperature of the second thermistor 5b does not drop below 150 ° C., which is within the safe range, the second thermistor 5b is rotated again and waits for the temperature to drop.

The temperature range of 150 ° C. or less, which is within the safe range, is a temperature range where the above-described problem does not occur. For reference, FIG. 8 shows a table showing the width and length of the paper passing area, the width of the non-paper passing area, the temperature rise temperature of the non-paper passing area when plain paper is passed, the offset situation, and the slip situation for each paper type.

This embodiment will be described by taking the COM10 envelope in FIG. 8 as an example, as in the above-described conventional example.

In this embodiment, COM1 is used in the same manner as in the conventional example.
Immediately after the envelopes have been continuously fed, the non-sheet-passing area heating temperature is 2
Although the temperature has risen to 30 ° C., the post-rotation is performed until the non-sheet passing area temperature (the temperature detected by the second thermistor 5b) reaches 150 ° C. as shown in FIG. Since the plain paper is passed through the nip in a state where the temperature of the non-sheet passing area is lowered, no adverse effect is caused by the temperature rise of the non-sheet passing area. Therefore, as shown in FIG. 8, all the items of offset and slip are OK without any problem.

Further, only when there is a restriction on the structure and specifications of the main body, it may be necessary to determine the upper limit of the post-rotation time and feed the next sheet. In this case, the upper limit is set to 60 seconds and the post-rotation is extended. By extending the rotation after the maximum of 60 seconds, the temperature rise in the non-sheet passing portion is considerably reduced, and the image defect level is not raised as a complaint from general users. Further, the time of 60 sec is a case of this configuration, and depending on the configuration, it is naturally possible to provide a time other than the upper limit of 60 sec.

(Second Embodiment) Next, a second embodiment of the present invention will be described. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the first embodiment, the post-rotation is extended to reduce the temperature rise in the non-sheet-passing area so as to prevent the image from being disturbed. Another problem is that it takes too much time.

FIG. 9 is a flowchart showing a specific method as a countermeasure.

The present embodiment differs from the first embodiment in that the control of “post-rotation extension & cooling fan” is added / changed as indicated by the dark spots shown in FIG.

In this embodiment, when the post-rotation is extended, the rotation speed of the fan, which is a cooling means attached to the main body, is increased to air-cool the non-sheet-passing area temperature-raising portion generated in the fixing device. effective. As a result, the effect of air-cooling the non-sheet-passing area is enhanced, so that there is an effect that the cooling time required in the first embodiment and the time until printing are reduced. In addition, this fan is a fan attached to cool around the electric parts of the main body,
A cooling fan dedicated to the fixing device may be used.

FIG. 10 shows a table comparing the effect of the fan with that of the first embodiment.

According to FIG. 10, when the fan is used, the cooling time until the temperature in the non-sheet passing area falls within the safe area is about 10 to 20 seconds compared to when the fan is not used.
Be shortened.

Here, as an example of the operation control of the fixing device of the second embodiment, a case where the COM10 envelope is continuously passed through the nip will be briefly described.

After the COM10 envelope has been continuously passed through the nip, the temperature of the non-paper passing area has risen to 230 ° C.
In order to lower this temperature, the post-rotation is extended, but in the first embodiment shown in FIG.
It took 60 seconds to lower the temperature to ° C. However, in the second embodiment shown in FIG.
At the time of, printing is possible.

In the present embodiment, the use of the cooling fan has been specifically shown. However, the same effect can be obtained by increasing the post-rotation speed during post-rotation to shorten the same cooling time. This is because the time required for the non-sheet passing area to contact the outside air having a lower temperature than the periphery of the fixing device is increased, thereby increasing the cooling effect.

By using this embodiment, the occurrence of image defects is of course eliminated, but the time until the next print is accepted is shortened and the user satisfaction is further increased as compared with the first embodiment. Become.

[0124]

As described above, according to the first aspect of the present invention, the length of the sheet interval is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature. The length of the inter-paper time between the first recording medium used for fixing and the succeeding recording medium subsequent to the first recording medium can be optimized, and image disturbance due to excessive temperature rise in the non-paper passing area of the nip can be achieved. Etc. can be prevented.

According to the second invention of the present application,
Since the length of the inter-sheet time is extended so that the subsequent recording medium enters the nip after the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature, the first recording medium continuously provided for fixing and the first recording medium It is possible to optimize the length of the inter-paper time with the succeeding recording medium following the above, and it is possible to prevent image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip.

Further, according to the third aspect of the present invention, since the length of the inter-paper time is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area becomes 180 ° C. or less, It is possible to optimize the length of the inter-sheet time between the first recording medium to be subjected to fixing and the succeeding recording medium subsequent to the first recording medium, and the image due to excessive temperature rise in the non-sheet passing area of the nip. Disturbance and the like can be prevented.

According to the fourth invention of the present application,
After passing through the nip of the first recording medium, the length of the sheet interval is extended so that the second recording medium enters the nip within the upper limit of 60 seconds, so that the first recording medium continuously provided for fixing and the succeeding recording medium follow the first recording medium. It is possible to optimize the length of the inter-sheet time with the subsequent recording medium, and it is possible to prevent image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip.

Further, according to the fifth invention of the present application, the length of the inter-paper time is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature, and at the time of the inter-paper time, the film interval is reduced. Since the member and the pressurizing member are driven to rotate, it is possible to optimize the length of the inter-paper time between the preceding recording medium continuously provided for fixing and the subsequent recording medium following the preceding recording medium. In addition, it is possible to prevent image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip.

Further, according to the sixth invention of the present application,
When the length of the preceding recording medium in the transport direction is equal to or less than the predetermined length, the length of the inter-paper time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature, so that continuous fixing is performed. It is possible to optimize the length of the paper interval between the first recording medium to be supplied and the next recording medium subsequent to the first recording medium, and prevent image distortion and the like due to excessive temperature rise in the non-paper passing area of the nip. can do.

Further, according to the seventh invention of the present application, when the length of the advance recording medium in the transport direction is 270 mm or less, the paper is kept until the non-sheet passing area temperature becomes the second predetermined temperature or less. Since the length of the time interval is extended, it is possible to optimize the length of the inter-paper time between the first recording medium continuously provided for fixing and the subsequent recording medium following the first recording medium,
Image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip can be prevented.

According to the eighth invention of the present application,
At least when the leading recording medium is fed to the nip by manual feeding, the length of the sheet interval is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature. The length of the inter-paper time between the advanced recording medium to be performed and the subsequent recording medium following the advanced recording medium can be optimized, and image distortion and the like due to excessive temperature rise in the non-paper passing area of the nip can be prevented. be able to.

Further, according to the ninth invention of the present application, the length of the inter-paper time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature, and cooling is performed during the inter-paper time. Since the cooling effect on the heating element by the means is increased from the time of the fixing process, the length of the inter-paper time between the first recording medium continuously provided for fixing and the subsequent recording medium following the first recording medium is optimized. Therefore, it is possible to prevent the image from being disturbed due to excessive temperature rise in the non-sheet passing area of the nip.

Further, according to the tenth aspect of the present invention,
Since the length of the inter-sheet time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature, and the rotation speed of the film member and the pressure member is increased from the time of the fixing process during the inter-sheet time, The length of the inter-paper time between the first recording medium continuously provided for fixing and the subsequent recording medium subsequent to the first recording medium can be optimized, and the excessive temperature rise in the non-sheet passing area of the nip can be achieved. Image disturbance and the like can be prevented.

Further, according to the eleventh aspect of the present invention, the length of the inter-sheet time is extended until the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature. The length of the sheet interval between the first recording medium and the succeeding recording medium following the first recording medium can be optimized, and image distortion due to excessive temperature rise in the non-sheet passing area of the nip can be prevented. Can be.

According to the twelfth aspect of the present invention, the length of the sheet interval is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area falls below the second predetermined temperature. Therefore, it is possible to optimize the length of the sheet interval between the first recording medium continuously provided for fixing and the succeeding recording medium subsequent to the first recording medium, resulting in an excessive rise in the non-sheet passing area of the nip. It is possible to prevent image disturbance or the like due to temperature.

Further, according to the thirteenth aspect of the present invention, the length of the inter-paper time is extended so that the late recording medium enters the nip after the temperature of the non-sheet passing area becomes 180 ° C. or less. The length of the inter-paper time between the first recording medium continuously provided for fixing and the subsequent recording medium subsequent to the first recording medium can be optimized, and the excessive temperature rise in the non-sheet passing area of the nip can be achieved. Image disturbance and the like can be prevented.

According to the fourteenth aspect of the present invention, the length of the inter-paper time is extended so that the subsequent recording medium enters the nip within the upper limit of 60 seconds after the preceding recording medium passes through the nip. It is possible to optimize the length of the inter-sheet time between the first recording medium to be subjected to fixing and the succeeding recording medium subsequent to the first recording medium, and the image due to excessive temperature rise in the non-sheet passing area of the nip. Disturbance and the like can be prevented.

Further, according to the fifteenth aspect of the present invention, the length of the inter-sheet time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. Since the film member and the pressurizing member are driven to rotate, it is possible to optimize the length of the inter-paper time between the preceding recording medium continuously provided for fixing and the subsequent recording medium following the preceding recording medium. Thus, image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip can be prevented.

Further, according to the sixteenth aspect of the present invention, when the length of the advance recording medium in the transport direction is equal to or less than the predetermined length, the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature. Since the length of the inter-paper time is extended until the following, the length of the inter-paper time between the first recording medium continuously provided for fixing and the subsequent recording medium following the first recording medium can be optimized. Thus, image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip can be prevented.

Further, according to the seventeenth aspect of the present invention, when the length of the advance recording medium in the transport direction is 270 mm or less, the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. Since the length of the inter-paper time is extended, it is possible to optimize the length of the inter-paper time between the preceding recording medium continuously provided for fixing and the subsequent recording medium following the preceding recording medium,
Image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip can be prevented.

Further, according to the eighteenth aspect of the present invention, the temperature of the non-sheet passing area becomes equal to or lower than the second predetermined temperature when the advance recording medium is fed into the nip by at least manual feeding. Since the length of the inter-paper time is extended up to this point, the length of the inter-paper time between the first recording medium continuously provided for fixing and the subsequent recording medium following the first recording medium can be optimized. In addition, it is possible to prevent image disturbance or the like due to excessive temperature rise in the non-sheet passing area of the nip.

Further, according to the nineteenth aspect of the present invention, the length of the inter-paper time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. Since the effect of cooling the heating element by the cooling means is increased from that at the time of the fixing process, the length of the inter-sheet time between the first recording medium continuously provided for fixing and the subsequent recording medium following the first recording medium is adjusted appropriately. It is possible to prevent the image from being disturbed due to excessive temperature rise in the non-sheet passing area of the nip.

According to the twentieth aspect of the present invention, the length of the inter-paper time is extended until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. Since the rotation speeds of the film member and the pressure member are increased from the time of the fixing process, the appropriate length of the inter-sheet time between the first recording medium continuously provided for fixing and the subsequent recording medium following the first recording medium is adjusted. It is possible to prevent the image from being disturbed due to excessive temperature rise in the non-sheet passing area of the nip.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2A is a cross-sectional view illustrating a schematic configuration of a heating device provided in the image forming apparatus of FIG. 1, and FIG. 2B is a block diagram illustrating a schematic configuration of a temperature control system thereof.

FIG. 3 is a view for explaining an arrangement position of each member in a longitudinal direction of the heating device of FIG. 2;

FIG. 4 is a diagram showing changes in detected temperatures by a first temperature detecting means and a second temperature detecting means in a conventional heating device.

FIG. 5 is a diagram showing a change in temperature in a sheet passing region and a non-sheet passing region of a heating element in a conventional heating device.

FIG. 6 is a diagram for explaining an image problem that occurs in a conventional heating device.

FIG. 7A is a flowchart for explaining drive control when a starting recording medium is fed from a manual feed unit in the heating device of the first embodiment, and FIG. 7B is a flowchart for explaining the first embodiment. 6 is a flowchart for describing drive control when a starting recording medium is fed from a cassette in the heating device of the embodiment.

FIG. 8 is a table showing a relationship between the size of a starting recording medium, the temperatures of a sheet passing area and a non-sheet passing area, and a problem occurrence state in the heating device of the first embodiment.

FIG. 9A is a flowchart for explaining drive control when a starting recording medium is fed from a manual feed unit in the heating device of the second embodiment, and FIG. 9B is a flowchart for explaining the second embodiment. 6 is a flowchart for describing drive control when a starting recording medium is fed from a cassette in the heating device of the embodiment.

FIG. 10A is a table showing a relationship between the size of the starting recording medium and the descending time length of the non-sheet passing area of the nip at the time between sheets according to the first embodiment; 9 is a table showing a relationship between the size of a starting recording medium and the length of time of descent of a non-sheet passing area of a nip at a time between sheets in the second embodiment.

FIG. 11 is a cross-sectional view illustrating a schematic configuration of a conventional heating device.

FIG. 12 is a diagram showing a transition of a temperature detected by a temperature detecting means provided in the heating device of FIG. 11;

FIG. 13 is a diagram showing a change in temperature in a sheet passing region and a non-sheet passing region of a heating element in the heating device of FIG. 11;

FIG. 14 is a flowchart for explaining drive control of a conventional heating device.

FIG. 15 is a flowchart for explaining drive control of a conventional heating device.

FIG. 16 is a table showing the relationship between the size of a starting recording medium, the temperatures of a sheet passing area and a non-sheet passing area, and a problem occurrence state in a conventional heating device.

17A is a diagram illustrating an example of an image in which no problem occurs during fixing in a non-sheet passing area of the nip in an excessively high temperature state, and FIG. FIG. 7 is a diagram illustrating an example of an image in which a problem occurs at the time of fixing in a heated state.

FIG. 18A is a diagram showing an example of an image in which a problem occurs during fixing in a non-sheet passing area of the nip in an excessively high temperature state,
FIG. 6B is a diagram illustrating an example of an image in which no problem occurs during fixing in a non-sheet passing area of the nip in an excessively high temperature state.

[Explanation of symbols]

 2 Film (film member) 3 Heating body 4 Pressure roller (Pressing body) 5a First thermistor (first temperature detecting means) 5b Second thermistor (second temperature detecting means) 10 CPU (control means) 21 Laser printer ( Image forming device) 25 Fixing device 29 Cassette N Nip P Recording medium

Continued on the front page F term (reference) 2H027 DA12 DA38 DA46 DC10 DC19 EA12 EC20 ED16 ED17 ED25 EE02 EE07 EF06 EF09 2H033 AA03 BA08 BA11 BA12 BA25 BA29 BA32 BE03 CA04 CA07 CA13 CA17 CA19 CA27 CA35 CA37 CA40 CA48 CA53 CA18 CA23 DA04 DA06 GA06

Claims (20)

[Claims] 1. A heating member for heating a recording medium carrying an image by receiving a supply from a power supply, an endless belt-shaped rotatable film member sliding on the heating member, and the heating member via the film member. A rotatable pressurizing body pressed against the body, wherein the pressurizing body is nipped and formed by pressing the heating body so that the recording medium is nipped and conveyed by the film member and the pressurizing body to be conveyed. In a heating device that performs a heating process while applying pressure, a first temperature detecting unit that detects a temperature of a heating body in a paper passing area of the nip, and a second temperature detecting unit that detects a temperature of the heating body in a non-paper passing area of the nip. Control means capable of controlling the power supply from the power supply to the heating element so that the sheet passing area temperature detected by the first temperature detecting means is maintained within the first predetermined temperature range, and the fixing means is continuously provided for fixing. Two The length of the inter-paper time from the nip of the preceding recording medium to the nip of the succeeding recording medium following the preceding recording medium in the recording medium until the non-sheet passing area temperature becomes equal to or lower than the second predetermined temperature. Or a heating device which can be extended for a predetermined time. 2. The method according to claim 1, wherein the film member and the pressurizing body are nip-connected to the subsequent recording medium after the non-sheet passing area temperature detected by the second temperature detecting means becomes equal to or lower than the second predetermined temperature after passing through the nip of the preceding recording medium. Claim 1 in which rush is possible.
A heating device according to claim 1. 3. The film member and the pressurizing member may enter the nip of the subsequent recording medium after the temperature of the non-sheet passing area detected by the second temperature detection unit becomes 180 ° C. or less after passing through the nip of the preceding recording medium. The heating device according to claim 1 or 2, wherein the heating device can be used. 4. The heating device according to claim 1, wherein the film member and the pressurizing member can enter the nip of the subsequent recording medium within an upper limit of 60 seconds after passing through the nip of the preceding recording medium. . 5. The heating device according to claim 1, wherein the film member and the pressurizing member are configured to be driven to rotate during a sheet interval. 6. The apparatus according to claim 1, wherein the extension of the inter-sheet time is set when the length of the advance recording medium in the transport direction is equal to or less than a predetermined length. The heating device according to claim 1. 7. The method according to claim 1, wherein the extension of the inter-sheet time is set when the length of the advance recording medium in the transport direction is 270 mm or less. The heating device according to Item. 8. The apparatus according to claim 1, wherein the extension of the inter-sheet time is performed when the advance recording medium is fed into the nip at least by manual feeding. Heating equipment. 9. A cooling means capable of cooling at least a non-sheet passing area of the heating element, wherein the cooling means is set to increase a cooling effect when the inter-sheet time is extended, as compared with the fixing process. The heating device according to any one of claims 1 to 8, wherein: 10. The film member and the pressurizing member are set so as to increase the rotation speed when the inter-sheet time is extended as compared with the time of the fixing process. The heating device according to Item. 11. An image forming apparatus for recording an image formed by a series of image forming processes on a recording medium, comprising the heating device according to claim 1. 12. The nip of the subsequent recording medium after the non-sheet-passing area temperature detected by the second temperature detecting means falls below the second predetermined temperature after the film member and the pressure body pass through the nip of the preceding recording medium. The image forming apparatus according to claim 11, wherein the image forming apparatus is capable of entering. 13. The film member and the pressurizing body may enter the nip of the subsequent recording medium after the temperature of the non-sheet passing area detected by the second temperature detection unit becomes 180 ° C. or less after passing through the nip of the preceding recording medium. Claim 11 to be possible
Or the image forming apparatus according to claim 12. 14. The image forming apparatus according to claim 11, wherein the film member and the pressurizing member can enter the nip of the subsequent recording medium within an upper limit of 60 seconds after passing through the nip of the starting recording medium. apparatus. 15. The image forming apparatus according to claim 11, wherein the film member and the pressure member are configured to be driven to rotate during a sheet interval. 16. The apparatus according to claim 11, wherein the extension of the inter-sheet time is set when the length of the advance recording medium in the transport direction is equal to or less than a predetermined length. The image forming apparatus according to claim 1. 17. The apparatus according to claim 11, wherein the inter-sheet time is extended when the length of the advance recording medium in the transport direction is 270 mm or less.
The image forming apparatus according to claim 1. 18. The apparatus according to claim 11, wherein the inter-sheet time is extended when the advance recording medium is fed into the nip at least by manual feeding. Image forming device. 19. A cooling unit capable of cooling at least the non-sheet passing area of the heating element, wherein the cooling unit is set so as to increase the cooling effect when the time between sheets is extended, as compared with the time of fixing processing. The image forming apparatus according to any one of claims 11 to 18, wherein: 20. The film member and the pressurizing member are set so as to increase the rotation speed when the inter-sheet time is extended as compared with the fixing process.
The image forming apparatus according to claim 1.