JP6808800B2 - Image forming apparatus and image forming control program of the image forming apparatus - Google Patents

Description

The present embodiment relates to a fixing device and a fixing temperature control program for the fixing device.

As a heat source of the fixing device mounted on the image forming apparatus, a lamp that emits infrared rays typified by a halogen lamp or a method of heating with Joule heat by electromagnetic induction has been put into practical use.

Generally, a fixing device is composed of a pair of a heating roller (or a fixing belt spanned by a plurality of rollers) and a press roller, but in order to maximize the thermal efficiency of the fixing device, the heat capacity of the component is reduced as much as possible. It is required to concentrate the heating area. From this point of view, in the above-mentioned heating method, since the heating width is wide, it is difficult to intensively apply the heat energy dispersed over a wide range only to the nip portion, and it is difficult to optimize the thermal efficiency.

Further, in the fixing device for electrophotographic, if heat generation unevenness occurs in the direction perpendicular to the paper transport direction, the fixing quality is affected. In particular, in the case of color printing, there is a possibility that differences in color development and gloss may occur.

Furthermore, in a fixing device with an extremely reduced heat capacity, the temperature of the part through which the paper does not pass rises extremely, which may cause problems such as warpage of the heater, deterioration of the belt, and speed unevenness due to expansion of the transport roller. It was. Further, it is not preferable to heat the portion through which the paper does not pass from the viewpoint of energy saving. Intensive heating of only the part through which the paper passes is an important technical issue from the viewpoint of environmental friendliness.

Japanese Unexamined Patent Publication No. 2000-243537

In view of the above problems of the prior art, the present invention provides a fixing device and a fixing temperature control program for the fixing device, which enables intensive and stable heating of the paper-passing area, and can achieve improvement of fixing quality and energy saving. With the goal.

The image forming apparatus of the present embodiment includes a determination means for determining the position of an image formed on a medium by a toner, an endless rotating body, a first heat generating member, and a length in a direction perpendicular to the conveying direction of the medium. A plurality of second heat-generating members having a length shorter than that of the first heat-generating member and arranged along the perpendicular direction of the first heat-generating member with a gap between the first heat-generating member and each other . A heating means that heats the rotating body, and a pressurizing means that press-contacts the heating means to form a nip and sandwiches and conveys the medium together with the heating means in the conveying direction. Regardless of the result of determining the position of the image, the first heat generating member is energized to generate heat, and the result of determining the position of the image is that the image formed on the medium to be conveyed is the second heat generating. when indicating that passes through the position of the member, the control means controls to heat by energizing one or more of a plurality of said second heat generating member Ru Ah at a position where the image formed on the medium passes through And.

The figure which shows the structural example of the image forming apparatus which mounts the fixing apparatus which concerns on Embodiment 1. FIG. 6 is an enlarged configuration diagram showing a part of an image forming portion in the first embodiment. The block diagram which shows the structural example of the control system of the MFP in Embodiment 1. FIG. The figure which shows the structural example of the fixing device which concerns on Embodiment 1. FIG. The layout drawing of the heat generating member group in Embodiment 1. The figure which shows the connection state of the heat generating member group and its drive circuit in Embodiment 1. FIG. The figure explaining the positional relationship between the heat generating member group and the printing area of a paper in Embodiment 1. FIG. The flowchart which shows the specific example of the control operation of the MFP in Embodiment 1. The layout of the heat generating member group in Embodiment 2. The figure which shows the connection state of the heat generating member group and its drive circuit at the time of the minimum paper size in Embodiment 2. FIG. The flowchart which shows the specific example of the control operation of the MFP in Embodiment 2.

<Embodiment 1>
FIG. 1 is a diagram showing a configuration example of an image forming apparatus on which the fixing apparatus according to the present embodiment is mounted. In FIG. 1, the image forming apparatus 10 is, for example, an MFP (Multi-Function Peripherals) which is a multifunction device, a printer, a copying machine, or the like. In the following description, the MFP will be described as an example.

A transparent glass platen 12 is provided above the main body 11 of the MFP 10, and an automatic document transport unit (ADF) 13 is provided on the platen 12 so as to be openable and closable. An operation panel 14 is provided on the upper part of the main body 11. The operation panel 14 has various keys and a touch panel type display unit.

A scanner unit 15 which is a reading device is provided below the ADF 13 in the main body 11. The scanner unit 15 reads a document sent by the ADF 13 or a document placed on a platen to generate image data, and includes a close contact type image sensor 16 (hereinafter, simply referred to as an image sensor). The image sensor 16 is arranged in the main scanning direction (depth direction in FIG. 1).

When the image sensor 16 reads the image of the original placed on the platen 12, the image sensor 16 reads the original image line by line while moving along the platen 12. This is executed over the entire document size to read one page of the document. Further, when reading the image of the original document sent by the ADF 13, the image sensor 16 is in a fixed position (position shown in the drawing).

Further, a printer unit 17 is provided in the central portion of the main body 11, and a plurality of paper feed cassettes 18 for accommodating various sizes of paper P are provided in the lower portion of the main body 11. The printer unit 17 has a photoconductor drum and a scanning head 19 including an LED as an exposure device, and scans the photoconductor with light rays from the scanning head 19 to generate an image.

The printer unit 17 processes the image data read by the scanner unit 15 and the image data created by a personal computer or the like to form an image on paper. The printer unit 17 is, for example, a tandem color laser printer, and includes image forming units 20Y, 20M, 20C, and 20K of each color of yellow (Y), magenta (M), cyan (C), and black (K). The image forming portions 20Y, 20M, 20C, and 20K are arranged in parallel on the lower side of the intermediate transfer belt 21 from the upstream side to the downstream side. Further, the scanning head 19 also has a plurality of scanning heads 19Y, 19M, 19C, 19K corresponding to the image forming units 20Y, 20M, 20C, 20K.

FIG. 2 is a configuration diagram showing an enlarged image forming unit 20K among the image forming units 20Y, 20M, 20C, and 20K. In the following description, since the image forming units 20Y, 20M, 20C, and 20K have the same configuration, the image forming unit 20K will be described as an example.

The image forming unit 20K has a photoconductor drum 22K which is an image carrier. A charged charger 23K, a developing device 24K, a primary transfer roller (transfer device) 25K, a cleaner 26K, a blade 27K, and the like are arranged around the photoconductor drum 22K along the rotation direction t. The exposure position of the photoconductor drum 22K is irradiated with light from the scanning head 19K to form an electrostatic latent image on the photoconductor drum 22K.

The charging charger 23K of the image forming unit 20K uniformly charges the surface of the photoconductor drum 22K. The developer 24K supplies a two-component developer containing black toner and carriers to the photoconductor drum 22K by a developing roller 24a to which a development bias is applied to develop an electrostatic latent image. The cleaner 26K uses a blade 27K to remove residual toner on the surface of the photoconductor drum 22K.

Further, as shown in FIG. 1, a toner cartridge 28 for supplying toner to the developing units 24Y to 24K is provided above the image forming portions 20Y to 20K. The toner cartridge 28 includes toner cartridges of each color of yellow (Y), magenta (M), cyan (C), and black (K).

The intermediate transfer belt 21 moves cyclically. The intermediate transfer belt 21 is stretched on the drive roller 31 and the driven roller 32. Further, the intermediate transfer belt 21 is in contact with the photoconductor drums 22Y to 22K facing each other. A primary transfer voltage is applied by the primary transfer roller 25K to the position of the intermediate transfer belt 21 facing the photoconductor drum 22K, and the toner image on the photoconductor drum 22K is primarily transferred to the intermediate transfer belt 21.

A secondary transfer roller 33 is arranged to face the drive roller 31 on which the intermediate transfer belt 21 is stretched. When the paper P passes between the drive roller 31 and the secondary transfer roller 33, the secondary transfer voltage is applied to the paper P by the secondary transfer roller 33. Then, the toner image on the intermediate transfer belt 21 is secondarily transferred to the paper P. A belt cleaner 34 is provided in the vicinity of the driven roller 32 of the intermediate transfer belt 21.

Further, as shown in FIG. 1, a paper feed roller 35 for transporting the paper P taken out from the paper feed cassette 18 is provided between the paper feed cassette 18 and the secondary transfer roller 33. Further, a fixing device 36 is provided downstream of the secondary transfer roller 33. A transport roller 37 is provided downstream of the fixing device 36. The transport roller 37 discharges the paper P to the paper ejection unit 38. Further, a reverse transfer path 39 is provided downstream of the fixing device 36. The reverse transfer path 39 reverses the paper P and guides it in the direction of the secondary transfer roller 33, and is used when performing double-sided printing. 1 and 2 show an example of carrying out the present invention, and do not limit the structure of the image forming apparatus portion other than the fixing device 36, and the structure of a known electrophotographic image forming apparatus can be used. it can.

FIG. 3 is a block diagram showing a configuration example of the control system 50 of the MFP 10 in the first embodiment. The control system 50 includes, for example, a CPU 100 that controls the entire MFP 10, a read-only memory (ROM) 120, a random access memory (RAM) 121, an interface (I / F) 122, an input / output control circuit 123, and a paper feed / transport control circuit. It includes 130, an image formation control circuit 140, and a fixing control circuit 150.

The CPU 100 realizes a processing function for image formation by executing a program stored in the ROM 120 or the RAM 121. The ROM 120 stores a control program, control data, and the like that control the basic operation of the image forming process. The RAM 121 is a working memory. The ROM 120 (or RAM 121) stores, for example, control programs such as the image forming unit 20 and the fixing device 36, and various control data used by the control programs. Specific examples of the control data in the present embodiment include a correspondence relationship between the size of the print area (width in the main scanning direction) in the paper and the heat generating member to be energized.

The fixing temperature control program of the fixing device 36 has a determination logic for determining the size of the image forming region on the paper on which the toner image is formed, and the image forming region passes through the paper before the paper is conveyed to the inside of the fixing device 36. It includes a heating control logic that controls heating in the heating means by selecting and energizing the switching element of the heat generating member corresponding to the position.

The I / F 122 communicates with various devices such as a user terminal and a facsimile. The input / output control circuit 123 controls the operation panel 123a and the display 123b. The paper feed / transport control circuit 130 controls the motor group 130a or the like that drives the paper feed roller 35 or the transport roller 37 of the transport path. The paper feed / transport control circuit 130 controls the motor group 130a and the like based on the control signal from the CPU 100 in consideration of the detection results of various sensors 130b in the vicinity of the paper feed cassette 18 or on the transport path. The image formation control circuit 140 controls the photoconductor drum 22, the charging device 23, the scanning head 19, the developing device 24, and the transfer device 25, respectively, based on the control signal from the CPU 100. The fixing control circuit 150 controls the drive motor 360 of the fixing device 36, the heating member 361, and the temperature detecting member 362 such as the thermistor, respectively, based on the control signal from the CPU 100. In the present embodiment, the control program and control data of the fixing device 36 are stored in the storage device of the MFP 10 and executed by the CPU 100. However, a calculation processing device and a storage device are separately provided for the fixing device 36. You may.

FIG. 4 is a diagram showing a configuration example of the fixing device 36. Here, the fixing device 36 applies tension to the plate-shaped heating member 361, the elastic layer, the endless belt 363 suspended on a plurality of rollers, the belt transport roller 364 for driving the endless belt 363, and the endless belt 363. It includes a tension roller 365 and a press roller 366 having an elastic layer formed on the surface. In the heating member 361, the heat generating portion side comes into contact with the inside of the endless belt 363 and is pressed in the direction of the press roller 366 to form a fixing nip having a predetermined width between the heating member 361 and the press roller 366. Since the heating member 361 heats while forming the nip region, the responsiveness at the time of energization is higher than that in the case of the heating method using a halogen lamp.

In the endless belt 363, for example, a silicon rubber layer having a thickness of 200 um is formed on the outer side of a SUS base material having a thickness of 50 um or a polyimide which is a heat resistant resin of 70 um, and the outermost periphery is covered with a surface protective layer such as PFA. .. In the press roller 366, for example, a silicon sponge layer having a thickness of 5 mm is formed on the surface of an iron rod having a diameter of 10 mm, and the outermost periphery thereof is covered with a surface protective layer such as PFA.

Further, in the heating member 361, a glaze layer and a heat generation resistance layer are laminated on a ceramic substrate. An aluminum heat sink is glued to the other side to allow excess heat to escape and prevent the board from warping. The heat generation resistance layer is formed of a known material such as TaSiO2, and is divided into a predetermined length and number in the main scanning direction.

The method for forming the heat generation resistance layer is the same as that of a known method (for example, a method for producing a thermal head), and a masking layer is formed of aluminum on the heat generation resistance layer. The aluminum layer is formed in a pattern in which adjacent heat generating members are insulated and the heat generating resistor (heating member) is exposed in the paper transport direction. To energize the heat generating member 361a, wiring is connected from the aluminum layers (electrodes) at both ends, and each is connected to the switching element of the switching driver IC. Further, a protective layer is formed at the uppermost portion so as to cover all of the heat generating resistor, the aluminum layer, the wiring and the like. The protective layer is formed of, for example, Si3N4.

FIG. 5 is a layout diagram of the heat generating member group in the present embodiment, and FIG. 6 is a diagram showing a connection state between the heat generating member group and its drive circuit. As shown in these figures, a plurality of heat generating members 361a having a predetermined width are arranged side by side in the main scanning direction (horizontal direction in the drawing) on the ceramic substrate, and the heat generating members 361a are arranged in the paper transport direction (up and down in the drawing). Electrodes 361b are formed at both ends in the direction). It is shown that each of the heat generating members 361a is individually controlled to be energized by the corresponding drive ICs 151a to 151d. Specific examples of the drive ICs 151a to 151d, which are switching portions of the heat generating member 361a, include switching elements, FETs, triaxes, switching ICs, and the like.

FIG. 7 is a diagram for explaining the positional relationship between the heat generating member group and the printing area of the paper in the first embodiment. Here, when the paper P is conveyed in the paper conveying direction indicated by the arrow A, only the heat generating member 361a corresponding to the position through which the printing area (image forming area) of the paper passes is selectively energized and heated. It is shown that That is, only the print area of the paper P is intensively heated. Further, in the present embodiment, it is assumed that the size of the print area of the paper P is determined before the paper P is conveyed into the fixing device 36. Examples of the method for determining the print area of the paper P include a method using the analysis result of image data, a method based on print format information such as a margin setting for the paper P, and a method based on the detection result of the optical sensor. Be done.

Hereinafter, the operation of the MFP 10 configured as described above at the time of printing will be described with reference to the drawings. FIG. 8 is a flowchart showing a specific example of control of the MFP 10 in the first embodiment.

First, when the image data is read by the scanner unit 15 (Act101), the image formation control program in the image forming unit 20 and the fixing temperature control program in the fixing device 36 are executed in parallel.

When the image formation process is started, the read image data is processed (Act102), the electrostatic latent image is written on the surface of the photoconductor drum 22 (Act103), and the electrostatic latent image is developed by the developing device 24. (Act104), proceed to Act114.

On the other hand, when the fixing temperature control process is started, the paper size and image data are printed based on, for example, the detection signal of the line sensor (not shown), the paper selection information by the operation panel 14, the analysis result of the image data, and the like. The size of each range is determined (Act105), and a group of heat generating members arranged at positions where the print range of the paper P passes is selected as a heat generating target (Act106). For example, in the example shown in FIG. 7, 14 heat generating members 361a arranged in the center corresponding to the width of the print area are selected.

Next, when the temperature control start signal for the selected heat generating member group is turned ON (Act107), the selected heat generating member group is energized and the temperature rises.

Next, when the surface temperature of the heat generating member group is detected by the temperature detecting member (not shown) arranged inside or outside the endless belt 363 (Act108), is the surface temperature of the heat generating member group within a predetermined temperature range? Whether or not it is determined (Act109). Here, if it is determined that the surface temperature of the heat generating member group is within a predetermined temperature range (Act109: Yes), the process proceeds to Act110. On the other hand, when it is determined that the surface temperature of the heat generating member group is not within the predetermined temperature range (Act109: No), the process proceeds to Act111.

In Act111, it is determined whether or not the surface temperature of the heat generating member group exceeds a predetermined temperature upper limit value. Here, when it is determined that the surface temperature of the heat generating member group exceeds a predetermined temperature upper limit value (Act111: Yes), the energization of the heat generating member group selected in Act106 is turned off (Act112). Return to Act108. On the other hand, when it is determined that the surface temperature of the heat generating member group does not exceed the predetermined temperature upper limit value (Act111: No), the surface temperature is less than the predetermined temperature lower limit value based on the determination result of Act109. Therefore, the energization of the heat generating member group is maintained in the ON state, or is turned ON again (Act113), and the process returns to Act108.

Next, when the paper P is conveyed to the transfer unit (Act110) while the surface temperature of the heat generating member group is within a predetermined temperature range, the toner image is transferred to the paper P (Act114), and then the paper P is fixed. Transport within 36.

Next, when the toner image is fixed on the paper P in the fixing device 36 (Act115), it is determined whether or not to end the printing process of the image data (Act116). Here, when it is determined that the printing process is finished (Act116: Yes), the energization of all the heat generating member groups is turned off (Act117), and the process is finished. On the other hand, when it is determined that the printing process of the image data has not been completed (Act116: No), that is, when the image data to be printed remains, the process returns to Act101 and the same process is repeated until the process is completed. ..

As described above, in the fixing device 36 according to the present embodiment, the heating member 361 is divided into a group of heat generating members having a predetermined length in a direction perpendicular to the transport direction of the paper P, and is arranged in contact with the inside of the endless belt 363. At the same time, the heat generating member group through which the print range (image formation area) of the image data passes is selectively energized. By switching the heat generation region based on the size of the print range of the image data, not only the abnormal heat generation of the non-passing portion can be prevented, but also the unnecessary heating of the non-passing portion can be suppressed, which is consumed by the fixing device 36. It is possible to significantly reduce thermal energy. Further, since the printed portion can be heated intensively and stably, the fixing quality can be improved.

<Embodiment 2>
Hereinafter, the fixing device 36 according to the second embodiment will be described with reference to the drawings. The configuration of the MFP 10 in the present embodiment is the same as that in the first embodiment, and the code common to the code assigned in the first embodiment also represents the same object. Hereinafter, the parts different from those of the first embodiment will be mainly described.

FIG. 9 is a layout diagram of the heat generating member group according to the second embodiment. The heating member 361 corresponds to a postcard size (100 x 148 mm), a CD jacket size (121 x 121 mm), a B5R size (182 x 257 mm), and an A4R size (210 x 297 mm). The heat generating element) is divided into 361a, which is different from the first embodiment. The heat-generating member group is energized so as to have a margin of about 5% in the heated region in consideration of the transfer accuracy of the conveyed paper, skew, and heat escape to the non-heated portion.

For example, in order to correspond to a width of 100 mm, which is the minimum size of a postcard, a first group of heat generating members is provided at the center in the main scanning direction (horizontal direction in the drawing), and the width is 105 mm. In order to correspond to the next largest sizes 121 mm and 148 mm, a second heat generating member group having a width of 50 mm is provided outside the first heat generating member group (in the left-right direction in the drawing), and 148 mm + 5% covers a width of up to 155 mm. In order to correspond to the larger sizes of 182 mm and 210 mm, a third heat generating member group having a width of 65 mm is provided on the outer side of the second heat generating member group to cover a width of up to 220 mm at 210 mm + 5%. .. The number of divisions of the heat generating member group and the width of each are given as an example, and are not limited thereto. For example, when the MFP 10 corresponds to five medium sizes, the heat generating member group may be divided into five according to each medium size.

Further, in the present embodiment, a line sensor (not shown) is arranged in the paper passing area, and the size and position of the passing paper can be determined in real time. At the start of the printing operation, the paper size may be determined from the image data or the information of the paper feed cassette 18 in which the paper in the MFP 10 is stored.

FIG. 10 is a diagram showing a connection state of the heat generating member group and its drive circuit when the paper size is the minimum size. Here, it is shown that when the paper P has the minimum size (postcard size), only the switching element of the first heat generating member arranged in the center is turned on and heated. As the size of the paper P increases, the switching elements of the second heat generating member group and the third heat generating member group are also controlled to be turned ON in sequence.

Hereinafter, the operation of the MFP 10 during printing in the present embodiment will be described with reference to the drawings. FIG. 11 is a flowchart showing a specific example of control of the MFP 10 in the second embodiment.

First, when the image data is read by the scanner unit 15 (Act201), the image formation control program in the image forming unit 20 and the fixing temperature control program in the fixing device 36 are executed in parallel.

When the image formation process is started, the read image data is processed (Act202), the electrostatic latent image is written on the surface of the photoconductor drum 22 (Act203), and the electrostatic latent image is developed by the developing device 24. (Act204), proceed to Act214.

When the fixing temperature control process is started, for example, the paper size is determined based on the detection signal of the line sensor (not shown) and the paper selection information by the operation panel 14 (Act205), and the paper P is placed at a position where the paper P passes. The heat-generating member group generated is selected as the heat-generating target (Act206).

Next, when the temperature control start signal for the selected heat generating member group is turned ON (Act207), the selected heat generating member group is energized and the surface temperature of the heat generating member group rises.

Next, when the surface temperature of the heat generating member group is detected by the temperature detecting member (not shown) arranged inside or outside the endless belt 363 (Act208), is the surface temperature of the heat generating member group within a predetermined temperature range? Whether or not it is determined (Act209). Here, if it is determined that the surface temperature of the heat generating member group is within a predetermined temperature range (Act209: Yes), the process proceeds to Act210. On the other hand, if it is determined that the surface temperature of the heat generating member group is not within the predetermined temperature range (Act209: No), the process proceeds to Act211.

In Act211 it is determined whether or not the surface temperature of the heat generating member group exceeds a predetermined temperature upper limit value. Here, when it is determined that the surface temperature of the heat generating member group exceeds a predetermined temperature upper limit value (Act211: Yes), the energization of the heat generating member group selected in Act206 is turned off (Act212). Return to Act208. On the other hand, when it is determined that the surface temperature of the heat generating member group does not exceed the predetermined temperature upper limit value (Act211: No), the surface temperature is less than the predetermined temperature lower limit value from the determination result of Act209. Therefore, the energization of the heat generating member group is maintained in the ON state, or is turned ON again (Act 213), and the process returns to Act 208.

Next, when the paper P is conveyed to the transfer unit (Act210) while the surface temperature of the heat generating member group is within a predetermined temperature range, the toner image is transferred to the paper P (Act214), and then the paper P is fixed. Transport within 36.

Next, when the toner image is fixed on the paper P in the fixing device 36 (Act 215), it is determined whether or not to end the printing process of the image data (Act 216). Here, when it is determined that the printing process is finished (Act216: Yes), the energization of all the heat generating member groups is turned off (Act217), and the process is finished. On the other hand, when it is determined that the printing process of the image data has not been completed (Act 216: No), that is, when the image data to be printed remains, the process returns to Act 201 and the same process is repeated until the process is completed. ..

As described above, the fixing device 36 according to the present embodiment classifies the size of the paper P into a plurality of groups, selects the switching elements of the heat generating members belonging to the heat generating member group previously associated with this group, and simultaneously selects the switching elements of the heat generating members. It is configured to be energized.

By switching the heat generating member group to be generated based on the group to which the paper size to be used belongs, it is possible not only to prevent abnormal heat generation in the non-passing paper portion but also to suppress unnecessary heating of the non-passing paper portion. As in the case of the first aspect, the heat energy consumed by the fixing device 36 can be significantly reduced. Further, since the switching of the heat generation target is not an individual heat generation member but a heat generation member group unit, the determination logic in the control program is simplified, and the determination is performed based on the print range of the image data. There is also an advantage that it can be easily implemented compared to.

Although the embodiment of the present invention has been described above, the present embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The present embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

For example, the configurations of the first embodiment and the second embodiment may be combined. That is, in the second embodiment, instead of the paper size, the heat generating member group can be selected based on the size of the print size (image forming region) as in the case of the first embodiment.

36 ... Fixing device 150 ... Fixing device control circuit 151, 151a, 151b, 151c, 151d ... Drive IC
361 ... Heating member 361a ... Heat generating member 362b ... Electrode 363 ... Endless belt 366 ... Pressurizing roller

Claims (6)

A determination means for determining the position of an image formed on a medium by toner, and
Endless shaped rotating body and
The length of the first heat-generating member and the direction perpendicular to the transport direction of the medium is shorter than that of the first heat-generating member, and a gap is provided between the first heat-generating member or each other. A heating means having a plurality of second heat-generating members arranged along the right-angled direction of the heat-generating member, and heating the rotating body.
A pressurizing means that press-contacts with the heating means to form a nip and sandwiches and conveys the medium together with the heating means in the conveying direction.
Regardless of the result of determining the position of the image, the first heat generating member is energized to generate heat, and the result of determining the position of the image is that the image formed on the medium to be conveyed generates the second heat. when indicating that passes through the position of the member, the control means controls to heat by energizing one or more of a plurality of said second heat generating member Ru Ah at a position where the image formed on the medium passes through When,
An image forming apparatus comprising. A determination means for determining the size of an image formed on a medium by toner, and
Endless shaped rotating body and
The length of the first heat-generating member and the direction perpendicular to the transport direction of the medium is shorter than that of the first heat-generating member, and a gap is provided between the first heat-generating member or each other. A heating means having a plurality of second heat-generating members arranged along the right-angled direction of the heat-generating member, and heating the inside of the rotating body.
A pressurizing means that press-contacts with the heating means to form a nip and sandwiches and conveys the medium together with the heating means in the conveying direction.
Regardless of the result of determining the size of the image, the first heat generating member is energized to generate heat, and the result of determining the size of the image is that the length of the region of the image in the perpendicular direction is the first. when indicating that exceeds the perpendicular length of the first heat generating member, and control means for controlling so as to generate heat by energizing the one or more pre-Symbol second heating member,
An image forming apparatus comprising. The length of the first heat generating member in the right angle direction is longer than the length of the medium having the smallest size in the right angle direction, and the length of each of the plurality of second heat generating members in the right angle direction is the smallest. The size is shorter than the length of the medium in the right angle direction,
The image forming apparatus according to claim 1 or 2. The plurality of second heat generating members are located on at least one of both sides of the first heat generating member.
The image forming apparatus according to any one of claims 1 to 3. The plurality of the second heat generating members are located on both sides of the first heat generating member.
The image forming apparatus according to claim 4. The length of the first heat-generating member and the direction perpendicular to the transport direction of the medium is shorter than that of the first heat-generating member, and a gap is provided between the first heat-generating member or each other. wherein a plurality of second heating member disposed along the perpendicular direction, have, an image formation control program of the image forming apparatus provided with a heating means for heating the rotating body of the heat generating member,
A determination step for determining the position of an image formed on a medium by toner, and
Regardless of the result of determining the position of the image, the first heat generating member is energized to generate heat, and the result of determining the position of the image is that the image formed on the medium to be conveyed generates the second heat. when indicating that passes through the position of the member, the control step of controlling so as to generate heat by energizing the one or more plurality of said second heat generating member Ru Ah at a position where the image formed on the medium passes through When,
An image formation control program of an image forming apparatus that causes a computer to execute.

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