JP2002251093A - Electrophotographic printer and fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic printer constituted so that releasing agent may be stably applied in a fixing device. SOLUTION: On the job, it is decided whether preliminary paper passing is necessary or not based on information on the necessity/unnecessity of the preliminary paper passing previously set as a table in accordance with the selected paper tray or the type of the selected paper, and in the case it is judged that preliminary paper passing is necessary, for example, in the case of a sealing paper, by making a normal paper, etc., other than the sealing paper pass through a fixing part 16 without forming an image on the paper in the case of the initial job after start-up, the excessive releasing agent 28 sticking to the heat roller 24 is stuck to the normal paper and removed from the roller 24. Then, the fixed quantity of releasing agent is stably stuck to the sealing paper, and a prescribed adhesion after press-fixation required for a sealing postcard is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for an electrophotographic printer of a fixing system having a releasing agent supply means. The present invention relates to an electrophotographic printer and a fixing device that ensure predetermined adhesiveness after printing on a sealing sheet with a commercial printer, and after pressing the sealing sheet.

[0002]

2. Description of the Related Art A fixing device of an electrophotographic printer is a device for fixing unfixed toner transferred to a sheet to the sheet by heat and pressure. In order to prevent a part of the toner that has been melted during fixing from fusing to the fixing roll side and causing problems such as jamming and soiling the subsequent paper, a release agent represented by silicone oil is applied to the fixing roll. It is proposed in Japanese Patent Publication No. 41-16990 or the like to prevent the toner from fusing by applying.

Japanese Patent Application Laid-Open No. 61-34574 proposes to attach a blade to a release agent supply system in order to keep the amount of the release agent applied to the fixing roll constant.

Hereinafter, a configuration of an electrophotographic printer according to the related art will be described with reference to FIGS.

When the main body of the electrophotographic printer 100 operates, a drive system (not shown) rotates the heat roll 104 of the fixing device 102. The drive is transmitted from the heat roll 104 via the donor roll 106, and the metering roll 108 rotates. Since the metalling roll 108 is in contact with the pad 112 to which the release agent 110 is soaked with a certain width, the release agent is applied to the metalling roll 108, and the excess is scraped off by the metaling blade 114, The heat is supplied to the heat roll 104 via the donor roll 106. Heat roll 104, metering roll 1
The temperature 08 is controlled by the machine control unit to a predetermined temperature. The pressure roll 116 is nipped with the heat roll 104 at a predetermined pressure by a spring, and is driven to rotate.

On the other hand, in the electrophotographic printer 100, as shown in FIG. 12, paper is fed from a paper feed tray 118 by a drive system (not shown), and a toner image is transferred to the paper by the image forming unit 120. The sheet S (see FIG. 13) holding the unfixed toner image is conveyed to the fixing device 102 and passes through the fixing nip (between the heat roll 104 and the pressure roll 116). The sheet S is reliably peeled off from the heat roll 104 by the pressure of the pressure roll 116, and the sheet S is surely peeled off from the heat roll 104 by the effect of the release agent 110 without wrapping of the sheet around the heat roll 104 or adhesion of the molten toner. After that, it is stored in the discharge tray 122.

In the case of the double-sided printing mode, after the toner image on the first surface of the paper is fixed, the toner image is reversed by the paper reversing device 124 in the conveyance path, transported to the image forming unit 120 again, and the toner image is transferred to the second surface of the paper. Is done. The sheet holding the unfixed image on the second surface is transported again to the fixing device 102 and fixed by the operation described above. After fixing, the sheet is discharged via a sheet conveying path.

When the number of printed sheets is large, paper is fed continuously, and the above-described operation is repeated at regular intervals. In the case of a large amount of double-sided printing, for example, only five sheets are continuously fed from the sheet feeding tray 118 according to the length of the double-sided exclusive path, and the transfer of the first side is performed.
The fixing is performed, and then the transfer and fixing of the five second surfaces through the reversing device 124 are performed. Then, the next five new sheets are continuously fed from the sheet feeding tray 118, and the transfer and fixing of the first surface are continued.

[0009]

SUMMARY OF THE INVENTION As described above, the printer 100
Then, when the machine body operates, the heat roll 104 starts rotating, so that the donor roll 106 and the metering roll 108 also rotate, and the release agent 11
0 is supplied. However, it takes some time before the paper is conveyed from the paper feed tray 118 to the fixing device 102. Therefore, by the time the sheet arrives at the fixing device 102, the release agent 110 is only supplied to the heat roll 104, and is excessively applied to the surface of the heat roll 104. Release agent 11 applied excessively
A value of 0 indicates that the sheet adheres to the sheet that first arrives at the fixing device 16 after the machine body is started.

Before the machine body is started, the surface of the heat roll is soaked and the amount of the release agent is reduced due to drying, etc. At the start of printing, the necessary and sufficient amount of the release agent is applied to the heat roll 104 and supplied. Must have been. Here, if the amount of the release agent is too small, the printing paper after fixing cannot be peeled off, and a wrapping jam occurs. Therefore, it is necessary to design a large amount, that is, to sufficiently perform preliminary rotation before printing. However, the amount of the release agent required for one A4 sheet is as small as about 2 to 4 mg as a saturated value during continuous running.
Since control is difficult, sufficient pre-rotation must be performed in anticipation of safety.When the initial printing paper comes, excessive release agent is attached to the surface of the heat roll, and as a result A large release agent will adhere to the initial printing paper.

As described above, the amount of the release agent adhering to the discharged sheet is the largest for the first sheet after the machine body is started, and then decreases rapidly, and becomes stable after the tenth sheet. The initial amount of the release agent attached to the printing paper may reach 5 to 10 times that during stable running.

In recent years, due to the revision of the Postal Law, postal notification services such as billing details, which have conventionally been sent mainly by envelopes, have special paper surfaces as disclosed in JP-A-11-244454. A system that applies glue, prints the paper with a printer, folds the paper with a high pressure using a device called a sealing machine, and presses it to create a postcard that can maintain confidentiality is often used. It has become to. By peeling the postcard after such crimping from the corner and opening both sides, confidential information on the inner surface can be seen. By doing so, the notification work, which conventionally had to use an envelope for confidentiality, can be sent by postcard, so that the postal expenses can be greatly reduced.

[0013] However, the sealing paper (spread paper) which is the source of the postcard is usually coated with glue on the entire surface on which the confidential information is to be printed. As described above, the amount of release agent (silicone oil) adhering to the paper may be several times as large as described above. In this case, the crimping property is extremely deteriorated. In some cases, confidential information leaked.

In order to avoid such a situation, there is a method in which the release agent on the paper is soaked in the paper for a long time before the post-processing by the sealing machine. There was a problem with efficiency.

SUMMARY OF THE INVENTION In order to solve such problems, an object of the present invention is to provide an electrophotographic printer and a fixing device in which a releasing agent is stably applied to the fixing device.

[0016]

According to a first aspect of the present invention, after a toner image is formed on a sheet to be conveyed, the toner image is applied to the sheet by a fixing roll having a surface coated with a release agent in a fixing unit. In an electrophotographic printer to be fixed, a job input unit for inputting a job for forming an image on a sheet, and a sheet on which an image is formed based on the job input from the job input unit before passing through the fixing unit And a pre-sheet passing means for transporting the sheet absorbing the release agent applied to the surface of the fixing roll to the fixing unit.

The operation of the present invention will be described.

According to the present invention, when a job is input by the job input means, before the paper on which an image is formed based on the job by the pre-sheet passing means passes through the fixing section, the separation applied to the surface of the fixing roll. The sheet absorbing the mold agent is transported to the fixing unit. As a result, the paper absorbs the release agent that is excessively present on the surface of the fixing roll in the early stage of driving. Therefore, even when the sealing paper or the like on which the image is formed is conveyed to the fixing unit, the predetermined adhesiveness can be secured without excessive release agent adhering.

According to a second aspect of the present invention, in the first aspect of the present invention, the pre-sheet passing means determines a necessity of the pre-sheet passing based on the job;
When the pre-sheet-passing determining unit determines that pre-sheet passing is necessary, a conveying unit that conveys a release agent absorbing sheet on which an image is not formed before the image-formed sheet to the fixing unit. It is characterized by becoming.

The operation of the second aspect will be described.

The pre-sheet passing process determining means determines the necessity of the pre-sheet passing based on the contents of the job, and only when the pre-sheet passing is necessary, the conveying means removes the release agent absorbing sheet on which the image is not formed. It is transported to the fixing unit. As a result, the excessive release agent on the fixing roll can be effectively absorbed.

As described above, if there is no problem even if the release agent excessively adheres to the fixing unit in the initial stage of the printer, such as plain paper, the pre-sheet passing is not performed, and the excessive release of the sealing paper or the like is performed. If the agent becomes a problem, perform pre-sheet passing. That is, since the pre-sheet passing is selectively performed as needed, it is possible to form an image economically and efficiently.

According to a third aspect of the present invention, in the second aspect of the present invention, the pre-sheet passing determining means includes a storage unit in which pre-sheet passing necessity information is set for each type of sheet. The paper determination unit determines whether or not pre-passing is necessary by referring to pre-passing necessity information set in the storage unit according to the type of paper selected by the job.

The operation of the third aspect of the present invention will be described.

In the pre-sheet passing determination means, the pre-sheet passing necessity information is set in the storage means for each type of sheet, so that the pre-sheet passing necessity information is set according to the type of sheet selected by the job. By referring to this, it is possible to determine the necessity of pre-sheet passing.

According to a fourth aspect of the present invention, in accordance with the third aspect of the present invention, there are provided a plurality of paper feed trays for supplying the paper to the transport means, and the storage means stores the paper stored in each paper feed tray. Type information is set, and the pre-sheet passing determination unit is configured to perform the pre-sheet passing based on the sheet type information and the pre-sheet passing necessity information set in the storage unit according to the sheet feed tray selected by the job. It is characterized in that the necessity of pre-sheet passing is determined by using this method.

The operation of the invention will be described.

If information on the type of paper stored in each paper feed tray is set in the storage means, the type of paper selected in the job is referred to by referring to the type information of the paper and the above-mentioned pre-pass necessity information. It is possible to reliably determine whether or not pre-sheet passing is necessary when an image is formed on a sheet in a sheet tray. In particular, even when the paper to be stored in the paper feed tray is changed, if the setting of the paper type information is changed, the pre-sheet passing determination unit can accurately determine whether or not the pre-sheet passing is necessary.

The invention according to claim 5 is the invention according to claim 3 or 4.
In the invention described in the above, the storage unit is set with availability information as the pre-sheet passing based on a type of sheet, and when the pre-sheet passing determining unit determines that pre-sheet passing is necessary, A sheet used for pre-sheet passing is selected based on the availability information set in the storage unit.

The operation of the invention will be described.

In the storage means, use permission information indicating whether or not the sheet can be used as pre-sheet passing is set based on the type of sheet. The type of paper to be used can be selected. Therefore, by setting, in the storage means, a sheet having a high unit price as a non-pre-sheet passing state or a sheet with a low release agent absorption rate as a pre-sheet non-sheet passing state, pre-sheet passing can be economically and effectively performed. It can be carried out.

According to a sixth aspect of the present invention, in accordance with the fifth aspect of the present invention, a plurality of paper feed trays for supplying paper to the transporting means are provided, and the pre-paper passing determining means determines that pre-paper passing is necessary. In this case, the paper feed tray to be used for pre-sheet passing is selected based on the availability information and the paper type information set in the storage unit.

The operation of the invention according to claim 6 will be described.

Since the usability information and the paper type information are set in the storage unit, the pre-sheet passing determination unit can use the pre-sheet passing based on the availability information if it determines that the pre-sheet passing is necessary. Paper type, and based on the paper type information, a paper feed tray storing paper of that type is selected. Therefore, the paper feed tray storing the paper of the type selected as the pre-paper passing by the pre-paper passing determination unit is selected, and the pre-paper passing can be performed.

According to a seventh aspect of the present invention, in a fixing device of an electrophotographic printer, a fixing roll for fixing a toner image formed on a sheet to the sheet and an amount of a release agent supplied to the fixing roll are adjusted. Release agent adjusting means for controlling the amount of the release agent adhered to the fixing roll within a predetermined range,
It is characterized by having.

The operation of the invention according to claim 7 will be described.

The amount of the release agent supplied to the fixing roll is adjusted by the release agent adjusting means to control the amount of the release agent attached to the fixing roll within a predetermined range. No amount of release agent adheres.

According to an eighth aspect of the present invention, in the invention of the seventh aspect, the release agent adjusting means includes a supply roll for supplying the release agent to the fixing roll, and an abutting contact with the supply roll. A release agent supplying means for supplying a release agent to the supply roll and changing a contact area with the supply roll.

The operation of the invention will be described.

In the present invention, since the release agent supply means for supplying the release agent to the supply roll can change the contact area with the supply roll, a fixed amount of the release agent is supplied at the initial stage of the printer. When the amount becomes excessive, the contact area with the supply roll is reduced to reduce the supply amount to the supply roll, and the amount of the release agent applied to the fixing roll surface is kept constant. As a result, it is possible to prevent the excessive release agent from adhering to the image forming surface also on the sheet on which the image is formed in the initial stage of the startup.

According to a ninth aspect of the present invention, in the seventh aspect of the invention, the release agent adjusting means is arranged at a predetermined interval in a width direction of the fixing roll, and sprays the release agent onto the fixing roll. A plurality of release agent jetting means and a release agent for controlling each release agent jetting means based on a parameter for changing the amount of release agent on the surface of the fixing roll such that the amount of release agent on the surface of the fixing roll is always uniform. And mold agent application control means.

The operation of the ninth aspect will be described.

In the present invention, since the release agent application control means controls each release agent injection means based on a parameter for changing the amount of the release agent on the fixing roll, for example, the temperature, the necessary release agent on the paper is controlled. A predetermined amount of release agent can be attached to the portion.

According to a tenth aspect of the present invention, in the invention of the seventh aspect, the release agent adjusting means applies the release agent of the fixing roll by contacting the fixing roll and follows the fixing roll. It is characterized by comprising a supply roll and braking means for braking the supply roll when the torque of the supply roll falls below a predetermined value.

The operation of the invention will be described.

The supply roll is in contact with the fixing roll (friction)
And is rotated following the fixing roll. Therefore, when the amount of the release agent applied to the surface of the fixing roll increases, the frictional force acting between the supply roll and the fixing roll decreases, and the torque acting on the rotation axis of the supply roll becomes equal to or less than a predetermined value. The rotation of the supply roll stops. As a result, the supply of the release agent to the fixing roll is stopped, and the release agent on the surface of the fixing roll is prevented from becoming excessive. When the paper passes and the amount of the release agent on the surface of the fixing roll decreases, the frictional force acting between the supply roll and the fixing roll increases, and the supply roll starts rotating again to supply the release agent to the fixing roll. In this way, by stopping the supply of the release agent to the fixing roll based on the amount of the release agent on the fixing roll surface, the amount of the release agent on the surface of the fixing roll is controlled within a predetermined range, and the excess release agent is Can be prevented from adhering to the sheet.

According to an eleventh aspect of the present invention, there is provided a fixing device of a printer of an electronic type or the like, wherein a fixing roll for fixing a toner image formed on a sheet to the sheet and a releasing agent are supplied to the surface of the fixing roll. Supply region changing means for changing a region for supplying the release agent to the fixing roll.

The operation of the eleventh invention will be described.

The supply area changing means supplies the release agent to the surface of the fixing roll, and can change the area for supplying the release agent. For example, the area where the release agent is adhered on the fixing roll can be changed by the supply area changing means so that the release agent does not adhere only to the adhesive portion of the sealing paper.

According to a twelfth aspect of the present invention, in the invention of the eleventh aspect, the supply area changing means includes a plurality of supply rolls that abut against different areas of the fixing roll and apply a release agent to the areas. A release roll applied region of the fixing roll is adjusted by bringing a selected one of the plurality of supply rolls into contact with the fixing roll.

The operation of the twelfth aspect will be described.

Since there are provided a plurality of supply rolls which contact different areas of the fixing roll and supply the releasing agent to the fixing roll, the supply roll is selectively brought into contact with the fixing roll, so that the surface of the fixing roll can be fixed. The release agent application area can be adjusted. Therefore, it can be adjusted so that the release agent does not adhere to an area where the release agent is not desirably adhered, such as an adhesive portion of the sealing paper.

According to a thirteenth aspect of the present invention, in the eleventh aspect of the present invention, the supply area changing means includes: a supply roll for supplying a release agent to the fixing roll; and a release agent attached to the supply roll. A release agent tray divided into a plurality of storage areas in which the release agent is stored, and a liquid capable of increasing or decreasing the liquid level of the release agent in a selected storage area among the plurality of storage areas. Surface adjustment means.

The operation of the invention will be described.

According to the present invention, the liquid level of the release agent stored in the predetermined storage area of the release agent tray is reduced in accordance with the size of the sheet conveyed to the fixing device, so that the sheet does not come into contact with the fixing agent. It is possible to prevent the release agent from being supplied to the roll surface area. As a result, it is possible to prevent the release agent from entering the widthwise end of the sheet on the surface of the fixing roll and unevenly distributing the release agent attached to the sheet.

[0056]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A printer according to a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the printer 10 includes four paper feed trays 12A to 12D for loading sheets before printing.
An image forming unit 14 that forms an image and prints it on paper;
Fixing device 16 for fixing an image printed on paper to paper
And a reversing device 18 for reversing the paper to perform printing on both sides, three discharge trays 20A to 20C for discharging and stacking the printed paper, and connecting the respective components,
And a transport path 22 having a plurality of transport roll pairs for transporting the paper.

The paper feed trays 12A to 12D are trays for stacking a fixed amount of paper and feeding the paper one by one. For example, one uppermost sheet is taken out from the stacked sheet bundle with a feed belt, and sent out to the conveyance path 22 by a pair of conveyance rolls.

The image forming section 14 is a system for developing a toner image and transferring it to a sheet by a known xerography (electrophotography) method using a photosensitive member.

The fixing device 16 is a device for fixing the unfixed image transferred to the sheet to the sheet by heat and pressure.

The reversing device 18 reverses the paper by, for example, a known inverter method, and enables an image to be formed on a non-printed surface. An intermediate tray may be provided instead of the inverter type.

The discharge trays 20A to 20C are trays for discharging and stacking printed paper.

Here, the fixing device 16 will be described in detail. As shown in FIG. 2, the fixing device 16 includes a heat roll 24 having a built-in heat source therein, a sheet S conveyed opposite to the heat roll 24, and
A pressure roll 26 disposed in a state of being urged by a spring or the like so as to press the release agent, a release agent tray 30 for storing a fixed amount of a release agent 28 to be supplied to the heat roll 24, A metering roll 32 containing a heat source for heating, and a release agent 2 stored in a release agent tray 30
8 is impregnated, and a pad 34 arranged so as to be in contact with the surface of the metering roll 32 to apply the release agent, and a certain amount of the release agent 28 applied to the surface of the metalling roll 32 by the pad 34. And a donor roll 38 for receiving the release agent 28 applied by the metering blade 36 from the surface of the metering roll 32 and applying the release agent 28 to the surface of the heat roll 24. Prepare.

The heat roll 24 is a cylindrical rotating body.
A heat source that receives power from a power source (not shown) and generates heat is built in the internal cavity, and is configured to heat the surface of the heat roll 24.

The pressure roll 26 is disposed at a position facing the heat roll 24, and is biased by a spring or the like (not shown) to be in a nip state. The sheet on which the unfixed image formed by the toner formed by the image forming unit 14 is transferred is
When passing between the nips, the toner is melted by the heat of the heat roll 24 and the pressure given by the pressure roll 26, and the image is fixed on the paper.

When the unfixed image is fixed on the sheet, the release agent 28 prevents the melted toner from adhering to the surface of the heat roll 24 so that the melted toner does not come off and jams the sheet (jam). It is used for the purpose of preventing a part of the paper from adhering to the surface of the heat roll 24 and soiling the subsequent paper. The release agent tray 30 holds the release agent 2 such as silicone oil.
8 is a tray for storing.

The metering roll 32 is a cylindrical rotating body, and a heat source that is supplied with power from a power source (not shown) and generates heat is built in the hollow inside thereof, and heats the surface of the metering roll 32. Configuration.

The pad 34 is formed of a sponge and is placed in the release agent tray 30 and immersed in the stored release agent 28.

The metalling roll 32 is arranged in the release agent tray 30 with the pad 34 interposed therebetween. When the metalling roll 32 rotates, the release agent 28 soaked in the pad 34 is removed. Applied to the surface.
By the heat of the metering roll 32, the release agent is warmed to have a desired viscosity, and the amount of the applied release agent is made constant.

The metering blade 36 is disposed so as to make a corner on the surface of the metering roll 32, and is urged by a spring (not shown). The release agent 28 applied to the surface of the metering roll 32 is scraped off to a fixed amount.

The donor roll 38 is a metalling roll 3
The release agent, which is disposed so as to be in contact with each of the two surfaces and the surface of the heat roll 24 and is applied in a fixed amount by the metering blade 36, is received from the surface of the metalling roll 32 and is applied to the surface of the heat roll 24. is there.

As shown in FIG. 3, the printer 10 includes an input interface unit 40, a printer controller unit 42, and a printer printing device 44 for controlling the release agent of the fixing device 16 (described later). Prepare.

The input interface unit 40 is an operation instruction unit for an operator or a user to operate the printer.

The paper type setting unit 46 determines whether or not it is necessary to convey a release agent-absorbing paper (hereinafter referred to as pre-paper passing) described below before traveling for printing for each type of paper, and whether or not the paper can be used as pre-paper passing. Is about to be entered.

The paper selection section 48 of the tray is to input the type of paper set in the paper feed trays 12A to 12D of the printer 10.

The job / use tray input section 50 is where an operator or a user inputs a job to be printed and a use permission tray.

The printer controller section 42 constructs the following components using a CPU, a program, a table, and the like stored in a memory. That is, the printer control unit 42 converts the contents of the job specified by the operator or the user into data of the specifications of the printer printing device 44 and transmits the data to the printer printing device 44.

The sheet type storage table 52 stores the necessity of pre-sheet passing and the availability of pre-sheet passing as attributes for each type of sheet.

The paper feed tray assignment storage table 54 stores the type of paper currently stored for each paper feed tray, its attributes, and the paper size.

The pre-sheet passing process judging section 56 judges which kind of paper feed tray used for the designated job requires pre-sheet passing, and if pre-sheet passing is necessary, the pre-sheet passing It is about to determine which paper feed tray to use as a tray.

The image processing section 58 understands the contents of the specified job, receives and processes the data, and sends the converted data to the printer 44.

The printer printing device 44 is a device that receives the image data, the print mode, and the data of the paper supply / discharge processing from the printer controller 42 and actually prints the data on paper.

The automatic paper size recognition unit 60 is to automatically detect the size of the paper set in the paper feed tray by a sensor (not shown) and send the size data to the tray assignment storage table 54.

The printer operation instructing section 62 is for specifically instructing and controlling the mechanical operation of the printer 10.

The traveling control section 64 controls a paper traveling system between paper supply and discharge of the printer 10.

The image forming section 66 is a printer operation instructing section 62
Image data from a printer,
The process from transfer to paper to image fixing is controlled.

The operation of the printer 10 thus configured will be described.

The operator or the user inputs the type of paper to be used by the paper type setting section 46 in advance. At this time, the necessity of pre-sheet passing before the job and the availability of pre-sheet passing are input as attributes for each type. The input result is, for example, a paper type storage table 52.
Is reflected as shown in Table 1.

[0089]

[Table 1]

The operator or user selects the type of paper set in each paper feed tray of the printing apparatus by the tray paper selection unit 48 in advance and stores it in the tray assignment table 54. The tray assignment table 54 is reflected as shown in Table 2 together with the paper size information recognized by the automatic paper size recognition unit 60.

[0091]

[Table 2]

An operator or a user inputs a job through the job / use tray input unit 50 and designates a use tray. For example, when the sheet feed tray d (12D) is selected, the pre-sheet passing process determination unit 56 refers to the tray assignment storage table 54. At this time, if the tray assignment storage table 54 is set as shown in Table 2, the tray I (12D) used for the job has
This means that the sealing paper with D = 4 is set. Subsequently, the pre-sheet passing process determining unit 56 refers to the sheet type storage table 52. At this time, if the paper type storage table 52 is set as shown in Table 1, the paper ID
It is necessary to perform a pre-sheet passing process before feeding a sealing sheet having a sheet ID of 4 as a job, and the sheets that can be used for the pre-sheet passing are plain paper having a sheet ID of 1 or single-sided having a sheet ID of 2 from Table 1. It turns out that it is used paper. It is from Table 2 that paper tray b (12B) or paper tray a
(12A). The paper size used for the pre-sheet passing is most preferably the same size as the job paper. If not, the paper size may be larger than the job paper. In this case, since the job paper is A4, the tray b (12B) (plain paper) is determined for pre-sheet passing.

When the image processing of the job proceeds by the image processing section 58, the printer operation instructing section 62 sends the traveling control section 64
A printing operation is instructed to the image forming unit 66.

After starting up, the printer printing device 44 first feeds a predetermined number of plain papers from the feed tray 12B used for pre-feeding, and then feeds sealing paper from the feed tray d (12D). To start.

On the other hand, in the fixing device 16, when the machine main body operates, a drive system (not shown) rotates the heat roll 24. Driving force is transmitted from the heat roll 24 via the donor roll 38, and the metering roll 32 rotates. The metalling roll 32 is used for the pad 3 on which the release agent 28 is stained.
4, the release agent is applied to the metalling roll 32, the excess is scraped off by the metalling blade 36, and is supplied to the heat roll 24 via the donor roll 38. The temperatures of the heat roll 24 and the metering roll 32 are controlled by a machine control unit so as to reach predetermined temperatures. However, since it takes a predetermined time for the plain paper to reach the fixing unit, the release agent 28 continues to be supplied to the heat roll 24 during that time, and becomes excessive.

In this state, plain paper on which no image is formed reaches the fixing unit 16. The pre-passed plain paper passes through a fixing nip (between the heat roll 24 and the pressure roll 26) and absorbs an excessive release agent 28 applied on the heat roll 24 at the initial stage of startup. Subsequently, the sealing sheet according to the present job on which the unfixed image is placed passes through the fixing unit 16. After the toner image is fixed on the sealing paper holding the unfixed toner image by the heat of the heat roll 24 and the pressure of the pressure roll 26, the heat roll 2
4 and is stored in the paper discharge tray 122 via the transport path. At this time, the toner does not wind around the heat roll 24 due to the effect of the release agent 28, and the fused toner of the paper that has passed previously does not adhere to the heat roll 24 and adhere to the subsequent sealing paper.

As described above, after the excess release agent 28 on the heat roll 24 is removed by the plain paper to be in a steady state, the sealing paper passes through the fixing device 16, so that a certain amount of the release agent 28 Adheres to the sealing paper. Therefore, the adhesive force of the sealing paper does not become insufficient due to the excessive release agent 28 adhering.

Since the plain paper used in the pre-sheet passing is unneeded printing paper, it is preferable that the plain paper is conveyed to a simple tray such as the paper discharge tray c (20C). The sheet is conveyed to the tray a (20A) or the discharge tray b (20B). Note that this pre-sheet passing process is also applied when resuming after temporarily stopping printing such as a jam or running out of toner.

In the case of the double-sided printing mode, after the image on the first side of the paper is fixed, the image is reversed by the paper reversing device 18 in the conveyance path, transported to the image forming unit 14 again, and the toner image is formed on the second side of the paper. Transcribed. The sheet holding the unfixed image on the second surface is transported again to the fixing device 16 and fixed by the above-described operation. After fixing, the sheet is discharged via a sheet conveying path.

When the number of prints is large, paper is fed continuously, and the above operation is repeated at regular intervals. In the case of a large amount of double-sided printing, for example, 5
Only the sheets are continuously fed from the sheet feed tray 12D to transfer and fix the second surface, and then transfer and fix the five second surfaces that have passed through the reversing device 18. Then, the next five new sheets are continuously fed from the sheet feed tray 12D so as to be followed by the transfer and fixing of the first surface.

As another configuration based on the technical idea of the present embodiment, the following can be considered.

In the simplest configuration, a job storage table is provided in the printer controller unit 42, and an item of necessity of pre-sheet passing is provided as an attribute of the job storage table. The pre-sheet feeding may be automatically performed from the same sheet feeding tray as needed.

Further, as a simple configuration, an item of necessity of pre-sheet passing is provided as an attribute of a sheet tray allocation table, and when a job and a sheet tray to be used are specified, the pre-sheet necessity data is transmitted. If necessary, paper is automatically fed from a paper feed tray that does not require pre-feeding, and then fed from a paper feed tray that requires pre-feeding in order to perform image formation based on the job. Good.

The printer 10 according to the present embodiment can easily enter the pre-sheet-passing mode only in the case of sealing paper or the like in which the amount of the release agent adhering at the time of fixing must be strictly controlled. The pre-paper absorbs a large amount of release agent, so it is possible to prevent excess release agent from adhering to the initial part of the sealing paper that is the job, and adhesion failure after post-processing of the printed sealing paper. Can be prevented.

Although the unit price of purchasing sealing paper is 8 to 10 times higher than that of plain paper, it is expensive. Since it is possible to use printed plain paper, it is much cheaper than using the sealing paper itself as pre-sheet passing. (Second Embodiment) Control of a release agent of a fixing device according to a second embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the present embodiment, only the configuration of the fixing device 16 is different, and therefore only the corresponding portion will be described.

The fixing device 16 is provided with an adjusting device 7 capable of adjusting the angle of the pad 34 disposed inside the release agent tray 30.
The only difference from the first embodiment is that it has 0.

The adjusting device 70 includes, for example, a plate 74 that is rotatable about the rotation shaft 72 at the bottom of the pad 34 so that the pad 34 contacts the metering roll 32 about the rotation shaft 72. The area can be adjusted. The contact area may be adjusted by moving the pad 34 (plate 74) closer to or away from the metering roll 32.

The operation of the printer 10 (fixing device 16) thus configured will be described.

When the machine body operates, a drive system (not shown) rotates the heat roll 24. Driving force is transmitted from the heat roll 24 via the donor roll 38, and the metering roll 32 rotates (follows). Metering roll 3
2 is in contact with the pad 34 on which the release agent 28 is soaked with a certain width (contact area), so that the release agent 28 is applied to the metering roll 32, and the excess is scraped off by the metaling blade 36. Is supplied to the heat roll 24 via the donor roll 38. However, for a while immediately after the start of the machine main body, the width of the pad 34 in contact with the metering roll 32 is minimized by the adjusting device 70, and the supply of the release agent 28 is minimized. After a predetermined number of sheets have passed through the fixing device 16, the control device (not shown) increases the width (contact area) of the pad 34 in contact with the metering roll 32 by using the adjusting device 70, and the release agent for the heat roll 24. The supply of the release agent 28 is increased and the amount of the release agent 28 adhering to the sheet is adjusted to be stable (constant).

Heat roll 24, metering roll 32
Is controlled by the control unit to be a predetermined temperature. The pressure roll 26 is nipped at a predetermined pressure by a spring.

When the sheet on which the unfixed image has been transferred passes between the heat roll 24 coated with the release agent 28 and the pressure roll 26 in this manner, the unfixed image is formed by the heat of the heat roll 24 and the pressure of the pressure roll 26. The image is fixed on the paper, and the heat roll 2
4 can be prevented from being wrapped around (jam) and stains caused by the adhered fused toner.

In the fixing device 16 according to the present embodiment, the width (contact area) of the pad 34 with respect to the metering roll 32 is reduced by the adjusting device 70 at the beginning of one of the startups when the release agent 28 is supplied to the heat roll 24. Therefore, it is possible to prevent an excessive amount of the release agent 28 from adhering to the heat roll 24. On the other hand, when the predetermined number of sheets S have passed continuously, the amount of the release agent 28 adhered to the sheet S from the initial stage of startup is increased by increasing the contact area of the pad 34 with the metering roll 32 by the adjusting device 70. Can be constant.

Therefore, even when printing is performed on the sealing paper by the printer 10 and then a sealing postcard is created by continuous pressing with a sealing machine, the amount of the release agent 28 adhering to the sealing paper by the fixing device 16 is reduced. Is constant, the adhesiveness of the sealing postcard is always ensured, and high productivity and high reliability can be obtained.

As another configuration of the adjusting device 70, another set of a metering blade that can be approached to and separated from the metering roll 32 is prepared in addition to the existing one. The blade is also brought into contact with the metalling roll 32 to peel off the excess release agent 28 from the metalling roll 32 with the two metalling blades, and is not shown after a predetermined number of sheets have passed through the fixing device 16. A configuration in which the supply amount of the release agent 28 to the heat roll 24 may be adjusted by separating one metaling blade from the metalling roll 32 may be adopted. (Third Embodiment) A release agent control of a printer according to a third embodiment of the present invention will be described. Note that the same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

This embodiment is suitable for printing on a sheet of paper such as sealing paper (two-page spread paper) whose functions such as adhesiveness are reduced depending on the position where the release agent 28 is attached.
The adhesive is ensured by preventing the release agent from adhering as much as possible to the area other than the predetermined printing area of the paper.

As shown in FIG. 5, the fixing device 16 according to this embodiment is provided with two donor rolls 38A and 38B for supplying the release agent 28 to the heat roll 24.

The donor roll 38A is always nipped between the heat roll 24 and the metering roll 32, and is rolled only at a portion corresponding to the print area 71 (see FIG. 6) of the adhesive surface 70A of the sealing paper 70. Is provided. This means that the release agent 28 is not applied partially to the paper passing area (the maximum width of the paper) of the heat roll 24, but that portion is covered with the sealing paper 70.
Is a print-inhibited area (adhesive portion) 72 peculiar to the heat roller 24, so that dirt such as toner does not adhere to the heat roll 24.
Further, it has been confirmed that the print prohibition area 72 of the sealing paper 70 has almost no influence on the peelability of the paper because it is about 5 to 6 mm from the edge of the normal paper.

On the other hand, the donor roll 38B is used for fixing an unfixed image on the address surface 70B of the plain paper or the sealing paper 70.
A roll is provided in a portion where the roll of A is not provided (a portion corresponding to an adhesive portion (print prohibition region) 72 provided outside the print region 71 (both ends and the center portion of the paper)). In the case of the address surface 70B of the sealing paper 70 or plain paper, there is a possibility that printing is performed on the entire surface.
The release agent 28 is applied to the entire area of the paper passing area.

The donor roll 38B can be moved toward and away from the heat roll 24 and the metering roll 32, and the release agent 28 can be selectively supplied to the heat roll 24. I have.

The operation of the fixing unit 16 of the printer 10 will now be described.

When fixing the adhesive surface 70A side of the sealing paper 70, the donor roll 38B is
4 and the metalling roll 32, and the release agent 28 is placed on the heat roll 24 only by the donor roll 38A.
Supply. The donor roll 38A is used for sealing paper 7
Since the roll is provided only in the portion corresponding to the printing area 71 of the glue surface 70A of No. 0, the release agent 28 is supplied only to the portion corresponding to the printing area 71 of the glue surface 70A in the paper passing area of the heat roll 24. Is done. Therefore, the release agent 28 does not adhere to the print-inhibited area 72 on the adhesive surface 70A of the sealing paper 70, and the print-inhibited area (adhesive portion) 72 can secure a predetermined adhesiveness.

On the other hand, the address surface 7 of the sealing paper 70
When printing 0B or plain paper, the donor roll 38B is nipped between the heat roll 24 and the metering roll 32. That is, the release agent 28 is supplied to the entire sheet passing area on the heat roll 24 by the donor roll 38A and the donor roll 38B. As a result, even when an image is formed on the entire surface of the sheet, an unfixed image can be reliably fixed.

As described above, since the release agent 28 does not adhere to the end of the paper (the print-prohibited area 72) which most contributes to the adhesive strength, when the sealing paper is pressed with a sealing machine to form a sealing postcard, Achieves about three times higher adhesive strength than the area where the agent has adhered (printing area 71), making it possible to create a sealing postcard that is difficult to peel regardless of the amount of release agent 28 that adheres to printing area 71. Becomes

As another example of this embodiment, as shown in FIG. 7, a donor roll 38C having a roll formed on the entire paper passing area is provided in place of the donor roll 38B, and the donor roll 38A is also heated by a heat roll. 24 and the metering roll 32 can be freely approached and separated. That is, when fixing the glue surface 70A side of the sealing paper 70 (when preventing the release agent 28 from adhering to the print prohibited area 72), only the donor roll 38A is used,
When fixing the address surface (non-glue surface) 70B side (when it is necessary to apply the release agent 28 to the entire paper passing area of the heat roll 24), only the donor roll 38C may be used. .

Further, as another example, the following can be considered. As shown in FIGS. 8A and 8B,
The donor roll 38D is configured so as to be able to expand and contract in the axial direction and expand and contract in the radial direction at the central portion in the axial direction, so that the release agent 28 does not adhere to the printing prohibited area 72 on the adhesive surface 70A side of the sealing paper 70. is there. The central portion of the donor roll 38D is configured to expand and contract by a pump mechanism (not shown).

When fixing the adhesive surface 70A side of the sealing paper 70 (when preventing the release agent 28 from adhering to the printing prohibited area 72), as shown in FIG. The donor roll 38D is shrunk to prevent the donor roll 38D from abutting on the portions corresponding to the print-inhibited areas 72 formed at both ends of the sealing paper 70, and the central part is reduced in diameter and formed at the central part of the sealing paper 70. Print prohibition area 72 formed at the center of print prohibition area 72
The donor roll 38D is prevented from coming into contact with a portion corresponding to the above.

On the other hand, when fixing the address surface (non-adhesive surface) 70B side (when it is necessary to apply oil to the entire paper passing area of the heat roll), as shown in FIG. By stretching the roll 38D, the release agent can be applied to the entire paper passing area.

By configuring the donor roll 38D in this manner, even with one donor roll, the release agent 2 is applied to an appropriate portion on both surfaces (adhesive surface and address surface) of the sealing paper 70.
8 can be applied. (Fourth Embodiment) A release agent control of a printer according to a fourth embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The only difference from the fixing device of the first embodiment is the configuration of the release agent tray 30, so only the relevant portions will be described.

The fixing device according to the present embodiment has a mechanism for controlling the adhesion range of the release agent 28 in accordance with different paper widths. That is, in order to cope with the problem of the adhesive strength variation of the sealing paper, the structure of the release agent tray 30A for applying the release agent is changed so that the partition plate 74 is provided between the A4 region and the B4 region which does not overlap with the A4 region. Provided, the first storage unit 7
6 and the second storage section 78.

The second storage section 78 is configured so that the release agent 28 can be supplied and discharged by the pump 82 through the discharge port 80.

Since the release agent tray 30A is configured as described above, the metalling roll 3 is used in the B4 area (hereinafter referred to as an unused area) which is not used when fixing A4 paper.
The release agent 28 can be discharged from the second storage section 78 so that the release agent 28 does not come into contact with 2. Therefore, heat roll 2
Unnecessary release agent 28 is prevented from flowing from the non-use area to the widthwise end of the A4 sheet on the surface of No. 4, and the amount of release agent 28 adhering to the A4 sheet can be made uniform.

As described above, it is possible to prevent the use of the release agent 28 from being applied to useless areas when an image is fixed on A4 paper in a B4 width printer or the like. Oil can be prevented from flowing in, and the unevenness in the amount of release agent attached to one sheet of paper can be suppressed. As a result, it is possible to minimize the variation in the adhesive strength when the sealing-processed sealing paper is subjected to the sealing processing. (Fifth Embodiment) A release agent control of a printer according to a fifth embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The only difference from the first embodiment is the configuration of the fixing device. Therefore, only the corresponding changes will be described.

As shown in FIG. 10, the fixing device 16 directly injects the heat roll 24, the pressure roll 26, the release agent tank 80 storing the release agent, and the release agent directly to the heat roll 24. Release agent injection nozzles 8 for
And oil control for controlling the individual release agent injection nozzles 82 so that the amount of the release agent on the surface of the heat roll 24 is always uniform with parameters such as the rotation speed of the heat roll 24, the running paper width, and the oil temperature. And a control mechanism 84.

With this configuration, the release agent control mechanism 84 controls only the release agent injection nozzle 82 arranged at a required position in accordance with various application papers with respect to the heat roll 24. Since the release agent 28 is selectively used, a required amount of the release agent 28 can be applied to a required location without bias, and the amount of the release agent 28 used can be suppressed.

Further, in the case of the sealing paper, the release agent can be applied evenly to the variation between pages and the printed portion, and as a result, stable adhesiveness can be secured. (Sixth Embodiment) A release agent control of a printer according to a sixth embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The only difference from the first embodiment is the configuration of the donor roll, so only the relevant changes will be described.

In the fixing device 16 according to this embodiment, FIG.
As shown in FIG. 1, a torque brake 86 is provided in a donor roll 38E.

In the fixing device 16 configured as described above,
The donor roll 38E that supplies the release agent 28 to the heat roll 24 is nipped by the heat roll 24, and is rotated (followed) by the driving force of the heat roll 24. The donor roll 38E has a built-in torque brake 86, and when the transmission force from the heat roll 24 is weak,
The rotation stops. Further, the donor roll 38E rotates the metering roll 32 which is also nipped by the transmission torque received from the heat roll 24. The metering roll 32 also has no driving force and rotates (follows) with the donor roll 38. The metering roll 32 is in contact with the pad 34 and the metering blade 36, and a predetermined load is applied.

In the normal state, the donor roll 38E
The driving force is transmitted from the heat roll 24, and a predetermined amount of the release agent is supplied to the heat roll 24 while rotating at the same speed as the heat roll 24. At this time, donor roll 3
In 8E, the following equation holds.

Th> Td + Tm (1) Here, Th is the driving torque from the heat roll Td is the load torque of the donor roll Tm is the load torque from the metering roll.

The viscosity of the release agent 28 decreases due to a temperature change or the like.
Is attached, the donor roll 38E and the heat roll 2
Since the left side of the expression (1) becomes smaller due to the decrease in the surface μ between the four, Th <Td + Tm (2), and the donor roll 38E and the metering roll 32 temporarily stop regardless of the driving of the heat roll 24. . During that time, the supply of the release agent to the heat roll 24 is restricted, but the release agent on the heat roll 24 is consumed and decreased with the passing of the paper, so that the amount of the release agent on the surface falls below the specified amount. Then, the surface μ rises and returns to the state of the formula (1), and the rotation follows the normal state, that is, returns to the release agent supply.

The supply amount of the release agent can be adjusted by changing the set load torque of the torque brake 86 of the donor roll 38E.

With this configuration, it is possible to prevent excessive supply of the release agent 28 to the heat roll 24 due to an environmental change or the like, and to keep the amount of the release agent on the heat roll 24 constant. The amount of the release agent adhering to the paper or the like can be kept constant at all times, and poor adhesion after pressure bonding can be prevented.

Further, the above configuration has advantages such as low cost, high reliability, and high versatility due to the simple structure.

[0144]

According to the present invention, a fixed release agent is applied from the fixing roll irrespective of the initial start-up or the change of the paper size. In particular, not only is a predetermined amount of the release agent applied to the sealing paper, but also the adhesive area is securely applied when the sealing paper is pressed by not applying the release agent to the adhesive area. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a printer according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a fixing device according to a first embodiment of the present invention.

FIG. 3 is a block diagram illustrating release agent control of the printer according to the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a fixing device according to a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a fixing device according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a positional correspondence between a donor roll and a glue surface of a sealing sheet.

FIG. 7 is a diagram illustrating a positional correspondence between a donor roll and a glue surface of a sealing sheet according to another example.

FIG. 8 is an explanatory view of a positional correspondence between a donor roll and a glue surface of a sealing sheet according to another example.

FIG. 9 is a schematic configuration diagram of a fixing device according to a fourth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of a fixing device according to a fifth embodiment of the present invention.

FIG. 11 is a schematic configuration diagram of a fixing device according to a sixth embodiment of the present invention.

FIG. 12 is a schematic configuration diagram of a printer according to a conventional example.

FIG. 13 is a schematic configuration diagram of a fixing device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Printer 16 ... Fixing device 24 ... Heat roll (fixing roll) 30 ... Release agent tray 32 ... Metalling roll (supply roll) 38 ... Donor roll (supply roll) 70 ... Sealing paper

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takeharu Nagai 3-7-1, Fuuchi, Iwatsuki-shi, Saitama Fuji Xerox Co., Ltd. Iwatsuki Office (72) Inventor Hideo Nemoto 3-7-1, Fuuchi, Iwatsuki-shi, Saitama No. Fuji Xerox Co., Ltd. Iwatsuki Office (72) Inventor Yasuhiro Ikuta 3-7-1, Fuwa, Iwatsuki City, Saitama Prefecture Fuji Xerox Co., Ltd. Iwatsuki Office F Term (Reference) 2H027 DE07 EA18 EC06 ED16 ED25 EE07 EE08 EH06 FA05 FA30 FA35 2H033 AA01 AA09 BA43 BA44 BA45 BA46 BA48 BA52 BA54 BB01 BB28 BB33 CA16 CA17 CA37 4F042 AA02 CC09 CC14

Claims (13)

[Claims] 1. An electrophotographic printer in which after a toner image is formed on a conveyed sheet, the toner image is fixed on the sheet by a fixing roll having a surface coated with a release agent in a fixing unit. A job input unit for inputting a job for forming an image, and a sheet on which an image is formed based on the job input from the job input unit passes through the fixing unit.
An electrophotographic printer comprising: a pre-sheet passing unit that conveys a sheet absorbing a release agent applied to the surface of the fixing roll to the fixing unit. 2. The pre-sheet passing means, wherein the pre-sheet passing determining means determines whether or not the pre-sheet passing is necessary based on the job, and the pre-sheet passing determining means determines that the pre-sheet passing is necessary. An electrophotographic printer comprising: a conveyance unit configured to convey, to the fixing unit, a release agent absorbing sheet on which an image is not formed before the sheet on which an image is formed. 3. The pre-sheet passing determination means includes a storage unit in which pre-sheet passing necessity information is set for each type of paper, and wherein the pre-sheet passing determination means includes a type of sheet selected by the job. 3. The electrophotographic printer according to claim 2, wherein the necessity of pre-sheet passing is determined by referring to the pre-sheet passing necessity information set in said storage means. 4. A pre-sheet passing determining means, comprising: a plurality of sheet feeding trays for feeding sheets to the transport means; and a storage section in which information on types of sheets stored in the respective sheet feeding trays is set. Determining the necessity of pre-sheet passing based on the sheet type information and the pre-sheet passing necessity information set in the storage unit according to the sheet feeding tray selected by the job. The electrophotographic printer according to claim 3, wherein 5. The storage means is set with information on whether or not it can be used as the pre-passage based on the type of paper. When the pre-passage determination means determines that pre-passage is necessary, 5. The electrophotographic printer according to claim 3, wherein a sheet to be used for pre-sheet passing is selected based on the availability information set in the storage unit. 6. A plurality of paper feed trays for supplying paper to the transporting means, wherein the pre-paper passing determining means determines whether or not the usable paper is set in the storage means when it determines that pre-paper passing is necessary. 6. An electrophotographic printer according to claim 5, wherein said paper feed tray to be used for pre-sheet passing is selected based on information and said paper type information. 7. A fixing device for an electrophotographic printer, wherein: a fixing roll for fixing a toner image formed on a sheet to the sheet; and a release agent supplied to the fixing roll is adjusted to adhere to the fixing roll. A release agent adjusting means for controlling the amount of the release agent within a predetermined range. 8. The release agent adjusting means includes: a supply roll for supplying a release agent to the fixing roll; and a supply agent for supplying the release agent to the supply roll by contacting the supply roll. The fixing device according to claim 7, further comprising: a releasing agent supply unit capable of changing a contact area. 9. The release agent adjusting unit is disposed at predetermined intervals in the width direction of the fixing roll, and includes a plurality of release agent injection units that sprays a release agent onto the fixing roll. A release agent application control unit that controls each release agent injection unit such that the release agent amount on the fixing roll surface is always uniform based on a parameter that changes the release agent amount. The fixing device according to claim 7, wherein: 10. The release agent adjusting unit applies a fixing roll release agent by contacting the fixing roll, and supplies a supply roll driven by the fixing roll; and a torque of the supply roll falls below a predetermined value. The fixing device according to claim 7, further comprising: a braking unit configured to brake the supply roll. 11. A fixing device for an electronic or other type printer, comprising: a fixing roll for fixing a toner image formed on a sheet to the sheet; a releasing agent supplied to a surface of the fixing roll; And a supply region changing means for changing a region for supplying the mold agent. 12. The supply area changing means includes a plurality of supply rolls that contact different areas of a fixing roll and apply a release agent to the areas, and the supply roll selected from the plurality of supply rolls is provided. The fixing device according to claim 11, wherein a release agent application area of the fixing roll is adjusted by being brought into contact with the fixing roll. 13. The supply area changing unit includes: a supply roll for supplying a release agent to the fixing roll; and a plurality of storage areas for adhering the release agent to the supply roll and storing the release agent. A divided release agent tray, and a liquid level adjusting means capable of increasing and decreasing the liquid level of the release agent in a selected storage area among the plurality of storage areas. 12. The fixing device according to item 11.