JP2016133707A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device that can prevent overshoot due to local overheating of a halogen lamp.SOLUTION: A fixing device 17 comprises: a fixing belt 51 and a pressure roller 40 that hold and convey a sheet P; a lamp part 60 that heats the fixing belt 51; and a temperature control part that controls a power to be supplied to the lamp part 60. The lamp part 60 includes a main lamp that heats the center part in the width direction of the fixing belt 51, and a sub lamp that heats the ends in the width direction of the fixing belt 51. The main lamp and sub lamp are formed to have an outer diameter at both ends in the width direction of a glass tube larger than the outer diameter at the center part; the glass tubes are arranged in proximity with each other; and the glass tubes are arranged to be in contact with each other at both ends in the width direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fixing device and an image forming apparatus that pressurize and heat a sheet to fix an unfixed image formed on the sheet.

  2. Description of the Related Art In recent years, a heat roller fixing method has been widely used as a fixing device used in an electrophotographic image forming apparatus such as a copying machine or a printer. A fixing device using a heat roller fixing system includes a roller pair (fixing roller and pressure roller) that are in pressure contact with each other, and after heating a pressure contact portion (fixing nip portion) of the roller pair by a heating unit, an unfixed toner image The toner image is fixed by heat and pressure by feeding and passing the paper on which the toner is formed to the pressure contact portion of the roller pair.

  As the heating means described above, a plurality of halogen heaters having different heating regions (heating regions) are used in combination in order to cope with various sizes of paper. For example, two halogen lamps, a main lamp corresponding to heating of a small size paper and a sub lamp provided with a heating area at the end in the width direction, provided with a heating area at the center in the width direction of the paper are heating members. There is a method in which it is housed and heated from the inside.

  In the halogen lamp, a tungsten filament, an inert gas, and a trace amount of halogen are accommodated in a straight tubular glass tube made of transparent quartz glass, and the end of the glass tube is sealed. In the halogen lamp, the filament generates heat and emits light when energized, and the heating member is heated by the radiation that passes through the glass tube. In order to heat the entire paper, the filament of the sub lamp is extended to the outside of the range through which the paper passes, and the region through which the paper does not pass is also heated slightly.

  When fixing by heating means using a halogen lamp, if the number of sheets to be processed continuously increases, the sheet passes through the area through which the sheet passes (paper passing area), whereas the sheet is deprived of heat. There is a problem that heat is accumulated in the non-sheet-passing region (non-sheet-passing region) and the temperature of the end part is partially increased. As a result, parts provided at the end such as a bearing may be deteriorated by heat.

  Further, the heating member has been promoted to have a low heat capacity in order to save energy and improve the immediate heat performance, and the change (temperature increase) when heated is large. Therefore, it is necessary to consider peripheral parts of the filament such as a glass tube as a heat source for the heating member. That is, the glass tube that accommodates the filament generally transmits the radiation from the filament, but when the paper is continuously passed, it is gradually heated to a high temperature of 500 ° C. or higher. After that, when the lamp is turned off, the radiation from the filament is not radiated, but the glass tube that has reached a high temperature may radiate the radiation and heat the heating member excessively, resulting in a temperature overshoot. .

  In particular, in the non-sheet passing region when the paper is being passed, since the temperature of the heating member is high, heat transfer due to radiation from the glass tube to the heating member is reduced, and the glass tube is in a high temperature state. maintain. Although it varies depending on the distance between the glass tube and the heating member, radiation from the glass tube that has reached a high temperature is radiated so as to spread in the width direction, thus affecting the paper passing area adjacent to the non-paper passing area. . Therefore, there is a tendency for overshoot to increase in the range from the end of the sheet passing area to the non-sheet passing area. In the above-described configuration, if paper is passed while the heating member is at a high temperature due to overshoot, image quality degradation such as high temperature offset occurs, so the heating member is kept waiting to cool the heating member. There was a problem of a drop.

  In order to solve such a problem, conventionally, after the continuous sheet passing is completed, the heat of the heating member is moved to another contacting member by a post-rotation operation in which the fixing member is rotated for a predetermined time. Control which cools a heating member was performed. By the way, in the image forming apparatus, power consumption is saved by the sleep mode in which the main system is shut down and stands by, but by performing the post-rotation operation, the time until the transition to the sleep mode is increased, Since extra rotational driving power is required, it has been an obstacle to energy saving. Therefore, in order to prevent overshoot after the paper is passed, a method has been proposed in which the heat source is turned off during paper passing to prevent abnormal temperature rise (see, for example, Patent Document 1).

JP 2003-76189 A

  In the fixing device described in Patent Document 1, the heat source is turned on for a predetermined time before the time when the trailing edge of the final recording medium (paper) in a series of jobs passes through the fixing position where the fixing roller and the pressure roller are pressed against each other. By turning it off, overheating of the fixing roller after continuous paper feeding is suppressed. However, since the heat source is forcibly turned off, a time until reheating is required, and when the temperature of the fixing roller is excessively lowered, a waiting time for raising the temperature is generated when the next sheet is passed. There was a fear. Further, in Patent Document 1, overheating in the non-sheet passing region is not taken into consideration, and there is a possibility that temperature unevenness occurs in the fixing roller.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing device and an image forming apparatus that can prevent overshoot due to local overheating of a halogen lamp.

  The fixing device according to the present invention includes a heating member and a pressure member that are rotatably provided, a lamp unit that heats the heating member, a temperature detection unit that detects a temperature of the heating member, and a supply to the lamp unit. A temperature control unit that controls electric power to be conveyed, and the heating member and the pressure member convey and convey the sheet inserted between them, and heat and add an unfixed toner image on the sheet. A fixing device that presses and fixes the sheet on the sheet, wherein when the direction along the width of the sheet to be conveyed is a width direction, the lamp unit heats the central part of the heating member in the width direction; A first lamp having a glass tube and a filament; and a second lamp having a glass tube and a filament for heating the end in the width direction of the heating member, wherein the first lamp and the second lamp are The glass tube The outer diameters of both ends in the width direction are formed larger than the outer diameter of the central part, and the glass tubes are arranged close to each other, and the glass tubes of each other are arranged at both ends in the width direction. It arrange | positions so that it may contact.

  In the fixing device according to the present invention, among the first lamp and the second lamp, a region where the glass tubes are in contact with each other is a sheet conveyed by the heating member and the pressure member. It may be configured to include a non-sheet passing region in a sheet having the maximum size in the width direction.

  In the fixing device according to the present invention, the first lamp and the second lamp are in the non-sheet passing region with respect to the width direction, and in the region where the filament is present, the glass tubes of each other. It is good also as a structure which is contacting.

  In the fixing device according to the present invention, the temperature control unit sets a temperature of the heating member heated by the lamp unit to a sheet temperature when fixing a plurality of sheets continuously, The electric power supplied to the lamp unit is controlled so as to maintain the temperature, and the fixing temperature is set before the paper to be fixed last passes through the nip portion where the heating member and the pressure member abut. May be set to a temperature lower than the sheet passing temperature.

  In the fixing device according to the present invention, the temperature control unit keeps the heating member at a predetermined temperature before and after passing the paper, so that the temperature is lower than the paper passing temperature. The standby temperature is set to the standby temperature before the sheet to be fixed last passes through the nip where the heating member and the pressure member abut. It is good also as composition to do.

  In the fixing device according to the present invention, the temperature control unit includes the number of passing sheets based on the number of sheets to be continuously fixed, the sheet information based on the type of the sheet to be fixed, or the environment information based on the installed environment. Depending on the above, it is possible to adopt a configuration in which the set temperature of the heating member is lowered and the set temperature is changed.

  The fixing device according to the present invention includes the heating member including at least an elastic layer formed of silicone rubber, and the heating member capable of heating the elastic layer by radiant heat of the lamp portion and heat conduction in the thickness direction. The distance from the first lamp and the distance from the second lamp may be equal to the inner region, or the distance from the first lamp may be shorter than the distance from the second lamp.

  In the fixing device according to the present invention, the heating member includes a fixing belt having a surface layer formed of a fluororesin, an elastic layer formed of silicone rubber, and a base material formed of polyimide resin, A metal cylindrical roller provided with a ramp portion, with respect to an inner region of a portion of the metal cylindrical roller that is wound around the fixing belt, from a distance from the first lamp and from the second lamp Or the distance from the first lamp may be shorter than the distance from the second lamp.

  In the fixing device according to the present invention, the first lamp and the second lamp are maintained at a predetermined interval by an insulator provided on each one of both ends in the width direction so that the respective glass tubes are in contact with each other. It is good also as a structure supported by.

  In the fixing device according to the present invention, the first lamp may be configured such that the filament is short-circuited at least in a region facing the filament of the second lamp existing in the non-sheet passing region.

  The fixing device according to the present invention may include a third lamp that heats the heating member, and the third lamp may be in contact with at least a glass tube of the second lamp.

  An image forming apparatus according to the present invention includes the fixing device according to the present invention.

  The image forming apparatus according to the present invention may be configured to be connectable to a cloud service.

  In the image forming apparatus according to the present invention, the temperature setting and the timing for lowering the temperature setting and the temperature change information are collected, and the temperature setting and the timing for lowering the temperature setting are fed back through a cloud service. It is good also as a structure.

  According to the present invention, by bringing adjacent halogen lamps into contact with each other, heat transfer is caused by contact heat conduction through the end portion, and the amount of heat is dispersed. Thereby, overshoot due to local overheating of the halogen lamp can be prevented.

1 is a schematic side view of an image forming apparatus according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a fixing device according to a first embodiment of the present invention. FIG. 3 is a side view showing a lamp portion of the fixing device according to the first embodiment of the present invention. It is sectional drawing of arrow AA in FIG. It is sectional drawing of arrow BB in FIG. It is a side view which shows the modification of the lamp | ramp part which concerns on 1st Embodiment of this invention. It is a schematic sectional drawing of the fixing device which concerns on 2nd Embodiment of this invention. FIG. 6 is a side view showing a lamp portion of a fixing device according to a second embodiment of the present invention. It is sectional drawing of arrow CC in FIG. It is sectional drawing of arrow DD in FIG. It is a schematic sectional drawing of the fixing device which concerns on 3rd Embodiment of this invention. It is a schematic sectional drawing of the fixing device which concerns on 4th Embodiment of this invention. FIG. 6 is a characteristic diagram showing a temperature change of a heating member during fixing. 1 is a schematic configuration diagram illustrating an image forming apparatus and a server connected to a cloud service.

(Image forming device)
Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic side view of an image forming apparatus according to an embodiment of the present invention.

  An image forming apparatus 1 according to an embodiment of the present invention includes an exposure device 11, a developing device 12, a photosensitive drum 13, a cleaner device 14, a charger 15, an intermediate transfer belt device 16, a fixing device 17, a paper feed tray 18, A paper discharge tray 19, a manual paper feed tray 38, and a paper conveyance path S are provided, and multi-color and single-color images are formed on a predetermined paper according to image data transmitted from the outside. .

  The image data handled in the image forming apparatus 1 corresponds to a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y). Accordingly, four developing devices 12, photosensitive drums 13, chargers 15, and cleaner devices 14 are provided so as to form four types of latent images corresponding to the respective colors. Black, cyan, magenta, and yellow are respectively provided. The four image stations Pa, Pb, Pc, and Pd are configured by these.

  The photosensitive drum 13 is disposed at the approximate center of the image forming apparatus 1. The charger 15 uniformly charges the surface of the photosensitive drum 13 to a predetermined potential. The exposure device 11 exposes the surface of the photosensitive drum 13 to form an electrostatic latent image. The developing device 12 develops the electrostatic latent image on the surface of the photosensitive drum 13 to form a toner image on the surface of the photosensitive drum 13. Through the above-described series of operations, a toner image of each color is formed on the surface of each photosensitive drum 13. The cleaner device 14 removes and collects residual toner on the surface of the photosensitive drum 13 after development and image transfer. The exposure apparatus 11 uses a laser scanning unit (LSU) provided with a laser irradiation unit that is a light source, a reflection mirror that reflects light, and the like. As the exposure apparatus 11, an LED writing head in which light emitting elements are arranged in an array may be used.

  The intermediate transfer belt device 16 is disposed above the photosensitive drum 13 and includes an intermediate transfer belt 21, an intermediate transfer belt driving roller 22, an intermediate transfer belt driven roller 23, an intermediate transfer roller 24, and an intermediate transfer belt cleaning device 25. ing. Four intermediate transfer rollers 24 are provided corresponding to the image stations for each color for YMCK.

  The intermediate transfer belt drive roller 22, the intermediate transfer belt driven roller 23, and the intermediate transfer roller 24 stretch the intermediate transfer belt 21 and move the surface of the intermediate transfer belt 21 in a predetermined direction (the direction indicated by an arrow M in the figure). It is configured as follows.

  The intermediate transfer belt 21 circulates in the direction of the arrow M, and the residual toner is removed and collected by the intermediate transfer belt cleaning device 25, and the toner images of the respective colors formed on the surfaces of the photosensitive drums 13 are sequentially transferred. As a result, a color toner image is formed on the surface of the intermediate transfer belt 21.

  The image forming apparatus 1 further includes a secondary transfer device 26 including a transfer roller 26a. A nip area is formed between the transfer roller 26a and the intermediate transfer belt 21, and the sheet conveyed through the sheet conveyance path S is nipped and conveyed. When the paper passes through the nip area, the toner image on the surface of the intermediate transfer belt 21 is transferred.

  The paper feed tray 18 is a tray for storing paper used for image formation, and is provided below the exposure device 11. The paper discharge tray 19 is provided on the upper side of the image forming apparatus 1 and is a tray for placing paper on which images have been formed. The manual paper feed tray 38 is a tray that is attached to the side surface of the image forming apparatus 1 so as to be openable and closable.

  The sheet transport path S includes a main path S1 provided in an S-shape and an inversion path S2 that branches in the middle of the main path S1 and rejoins. A pickup roller 31 and a manual pickup are provided along the main path S1. A roller 39, a pre-registration roller 33, a registration roller 32, a secondary transfer device 26, a fixing device 17, and a paper discharge roller 34 are arranged. The reverse path S <b> 2 branches from between the fixing device 17 and the paper discharge roller 34, and rejoins between the pre-registration roller 33 and the registration roller 32 via the plurality of conveyance rollers 35.

  The pickup roller 31 is a drawing roller that is provided near the end of the paper feed tray 18 and supplies the paper from the paper feed tray 18 to the paper transport path S one by one. The manual pickup roller 39 is a draw-in roller that is provided near the end of the manual paper feed tray 38 and supplies the paper from the manual paper feed tray 38 to the paper transport path S one by one. The registration roller 32 temporarily holds the paper transported from the paper feed tray 18, and transports the paper to the transfer roller 26a at a timing when the leading edge of the toner image on the photosensitive drum 13 and the leading edge of the paper are aligned. The pre-registration roller 33 is a small roller for promoting and assisting the conveyance of the paper.

  The fixing device 17 fixes an unfixed toner image on a sheet. The paper after fixing is discharged onto the paper discharge tray 19 by the paper discharge roller 34. The fixing device 17 will be described in detail with reference to FIG.

  When image formation is performed not only on the front side of the paper but also on the back side, the paper is conveyed in the reverse direction from the paper discharge roller 34 to the reverse path S2, and the front and back of the paper are reversed, and the paper is transferred to the registration roller 32. Then, the image is formed on the back surface in the same manner as the front surface, and the paper is carried out to the paper discharge tray 19.

  The paper on which the image is formed by the image forming apparatus 1 is not limited to plain paper, and various recording materials such as postcards, envelopes, cardboard, and OHP films can be used.

(Fixing device)
The fixing device 17 according to the present invention includes four embodiments having different configurations. Hereinafter, each of the fixing devices 17 according to the first to fourth embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 2 is a schematic cross-sectional view of the fixing device according to the first embodiment of the present invention.

  The fixing device 17 according to the first embodiment of the present invention is a belt fixing method, and the fixing belt 51 is wound around the fixing roller 81 and the heating roller 71. In the fixing device 17, the pressure roller 40 (an example of a pressure member) is pressed against the fixing roller 81 via the fixing belt 51, and the sheet P is sandwiched and conveyed between the fixing belt 51 and the pressure roller 40. . The fixing roller 81 and the pressure roller 40 are pressed against each other by a spring or the like that applies a load, and the load is 400N. As a result, a fixing nip portion Nf having a length of about 7 mm in the conveyance direction of the paper P is formed between the fixing roller 81 and the pressure roller 40. When the paper P passes through the fixing nip portion Nf, an unfixed toner image formed with the toner T is fixed by being pressurized and heated. Hereinafter, for the sake of explanation, a direction parallel to the width of the paper P is referred to as a width direction X (see FIG. 3 described later). The width direction X is parallel to the axial direction of the fixing roller 81, the pressure roller 40, and the heating roller 71.

  In the fixing device 17, when the paper P is conveyed, the pressure roller 40 is rotationally driven by a rotational driving unit (not shown) formed by a motor, a gear, or the like, and the fixing roller 81, the fixing belt 51, and The heating roller 71 rotates following the driving of the pressure roller 40. In this embodiment, the rotation driving unit is connected to the pressure roller 40, but the rotation driving unit may be connected to the fixing roller 81 and the heating roller 71 to be rotated.

  The fixing roller 81 has a two-layer structure in which a fixing elastic layer 81b is formed around a cylindrical fixing core 81a. The fixing core 81a is a hollow or solid shaft, and is made of, for example, a metal or alloy such as iron, stainless steel, aluminum, and copper. The fixing elastic layer 81b is formed of silicone rubber, fluorine rubber, or sponge rubber obtained by foaming them.

  In the present embodiment, the fixing core metal 81a is a solid shaft made of iron and having an outer diameter of 20 mm, and the fixing elastic layer 81b has a thickness of 5 mm and an Asker C hardness of 40 degrees. It is made of sponge rubber. The fixing core metal 81a is formed sufficiently longer than the paper P in the width direction X, and the fixing elastic layer 81b is shorter than the fixing core metal 81a, and the range provided in the width direction X is 330 mm. ing.

  The pressure roller 40 has a three-layer structure in which a pressure elastic layer 42 is formed around a cylindrical pressure core 41 and a pressure release layer 43 is provided on the surface of the pressure elastic layer 42. Yes. The pressure cored bar 41 is a hollow or solid shaft, and is formed of, for example, a metal or an alloy such as iron, stainless steel, aluminum, and copper. The pressure elastic layer 42 is made of silicone rubber, fluorine rubber, or sponge rubber obtained by foaming them. The pressure release layer 43 is made of a fluororesin such as PFA (a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) or PTFE (polytetrafluoroethylene).

  In the present embodiment, the pressure cored bar 41 is a hollow shaft made of iron, having an outer diameter of φ26 mm and a thickness of 1 mm, and the pressure elastic layer 42 has a thickness of 2 mm and an Asker C hardness. The pressure release layer 43 is formed of a PFA tube having a thickness of 50 μm. In the pressure roller 40, as in the fixing roller 81, the pressure elastic layer 42 (pressure release layer 43) is provided on a part of the pressure core bar 41, and the range provided in the width direction X is within the range. 330 mm.

  The fixing belt 51 is an endless belt having a three-layer structure, and includes a base material, an elastic layer formed on the surface of the base material, and a release layer formed on the surface of the elastic layer. . The base material is formed, for example, by adding a copper layer to a heat-resistant resin such as polyimide, polyamide, and aramid resin, or a metal material manufactured by rolling or electroforming such as stainless steel or nickel. As the material of the elastic layer, for example, an elastomer material such as silicone rubber or fluororubber is used. For example, a fluororesin such as PFA or PTFE is used for the release layer. By using a belt structure having a small heat capacity, the temperature can be efficiently increased in a short time.

  In the present embodiment, the fixing belt 51 is formed of a silicone rubber having a thickness of 150 μm using a polyimide base material having a length in the width direction X of 320 mm, an inner diameter of φ40 mm, and a thickness of 50 μm. The base material is coated with an elastic layer and a release layer formed of PFA having a thickness of 12 μm.

  The heating roller 71 is a metal cylindrical roller, and includes a cylindrical cored bar, a heat absorption layer provided inside the cored bar, and a resin layer provided outside the heated cored bar. It has a three-layer structure. The core of the heating roller 71 may be formed of the same material as the fixing core 81a and the pressure core 41. The resin layer is made of a fluororesin such as PFA or PTFE, and reduces the frictional force with the fixing belt 51. A lamp unit 60 including a halogen lamp is inserted inside the heating roller 71 and is heated by radiation emitted from the halogen lamp. By the way, the metal material used for the core of the heating roller 71 generally has a low emissivity and reflects radiation from a halogen lamp, so that good heating efficiency cannot often be obtained. Therefore, in the present embodiment, for example, by providing a heat absorption layer formed of a material with high emissivity such as silicon resin, fluororesin, imide resin, metal oxide, and carbon on the inner side of the metal core, radiation is achieved. Easy to absorb the line. The lamp unit 60 will be described in detail with reference to FIGS. 3 to 4B described later.

  In the present embodiment, the heating roller 71 uses a stainless steel core bar having an outer diameter of 20 mm and a thickness of 0.1 mm. The resin layer is formed by applying a PTFE coat to the core metal and has a thickness of 20 μm. The heat absorption layer is formed by applying and baking a metal oxide paint. In the heating roller 71, the resin layer is provided on a part of the core metal, and the range provided in the width direction X is 325 mm.

  The fixing device 17 further includes two thermistors (a central thermistor 91 a and an end thermistor 91 b), a paper passing sensor 92, and a peeling claw 93. In the present embodiment, the two thermistors are provided at positions facing the heating roller 71 with the fixing belt 51 interposed therebetween, and detect the temperature of the fixing belt 51. The two thermistors will be described in detail with reference to FIG.

  The sheet passing sensor 92 is provided on the downstream side of the fixing nip portion Nf in the conveyance direction of the sheet P, and detects the sheet P passing therethrough. The paper passing sensor 92 may be a known mechanical, optical, or electrical sensor. In the detection result of the paper passing sensor 92, the paper passing sensor 92 passes through the state where the paper P is detected and the state where the paper P is not detected. And the rear end can be discriminated.

  The peeling claw 93 is provided downstream of the fixing nip portion Nf in the rotation direction of the fixing roller 81 and close to the peripheral surface of the fixing belt 51 (fixing roller 81), and the paper P that has passed through the fixing nip portion Nf. The sheet P is peeled from the fixing belt 51 in contact with the leading end of the sheet.

  Next, it demonstrates in detail based on drawing which shows the lamp | ramp part 60. FIG.

  3 is a side view showing the lamp portion of the fixing device according to the first embodiment of the present invention, FIG. 4A is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 3 is a cross-sectional view of arrow BB in FIG.

  A sheet passing area PW shown in FIG. 3 indicates a sheet P having a maximum size in the width direction X among the sheets P conveyed by the image forming apparatus 1. The sheet passing area PW is narrower than the fixing belt 51 in the width direction X. Note that the image forming apparatus 1 may perform image formation on the paper P that is narrower than the paper passing area PW. At this time, the paper P is conveyed so that the center in the width direction X substantially coincides with the center of the paper passing area PW. In the first embodiment, the heated portion HK heated by the lamp unit 60 is a heating roller 71, and the fixing belt 51 is heated via the heating roller 71. That is, in the width direction X, the region where the fixing belt 51 is heated substantially coincides with the region where the heating roller 71 is heated by the ramp unit 60, and the heating roller 71 and the fixing belt 51 are heated by the ramp unit 60. It corresponds to the heating member TB.

  The lamp unit 60 is provided with a plurality of halogen lamps (the main lamp 110 and the sub lamp 120) as heat sources. The plurality of halogen lamps are formed such that the outer diameters of both end portions in the longitudinal direction (width direction X) are larger than the outer diameter of the central portion, and both end portions of adjacent halogen lamps are in contact with each other. Specifically, the lamp unit 60 includes a main lamp 110 (first lamp), a sub lamp 120 (second lamp), an insulator 61, and a lead wire 62. In other words, the lamp unit 60 (two lamp structure 60 a) has a structure including two halogen lamps, that is, the main lamp 110 and the sub lamp 120. In the following description, the main lamp 110 and the sub lamp 120 may be collectively referred to as a halogen lamp for explanation.

  The main lamp 110 and the sub lamp 120 are halogen lamps that are sealed by containing a filament formed of tungsten, an inert gas, and a small amount of halogen in a glass tube (bulb) formed of transparent quartz glass. is there. The main lamp 110 and the sub lamp 120 are integrated with both ends held by the insulator 61. Lead wires 62 are connected to both ends of the main lamp 110 and the sub lamp 120, and electric power is supplied to the filament via the lead wires 62. The insulator 61 has an outer diameter of about φ13 mm. In the following, in order to distinguish between them, the glass tube and filament of the main lamp 110 may be referred to as a main bulb 111 and a main filament 112, and the glass tube and filament of the sub lamp 120 may be referred to as a sub bulb 121 and a sub filament 122. .

  The main lamp 110 corresponds to heating of the small size paper P, and a heating region RH is provided in the center in the width direction X. Specifically, the filament is formed by being spirally wound, and in the heating region RH, the amount of heat generation is increased by increasing the number of turns per unit length. That is, the main filament 112 is densely wound at the center in the width direction X (main filament center portion 112b), and is sparsely wound at both ends (main filament end portion 112a) in the width direction X. The heating area RH of the main lamp 110 is a range narrower than the sheet passing area PW in the width direction X.

  Unlike the main lamp 110, the sub lamp 120 is provided with heating regions RH at both ends in the width direction X. That is, the subfilament 122 is wound sparsely in the center in the width direction X (subfilament center portion 122b) and densely wound in both ends (subfilament end portion 122a) in the width direction X. The heating area RH of the sub lamp 120 is provided at the end of the sheet passing area PW, and extends beyond the range of the sheet passing area PW. That is, the sub lamp 120 heats a part of the non-sheet passing area where the heating member TB and the sheet P do not contact (non-sheet passing heating area RK).

  Both ends of the main filament central portion 112b overlap with part of the subfilament end portion 122a in the width direction X. Therefore, the main lamp 110 and the sub lamp 120 cover the entire area of the sheet passing area PW by combining the heating areas RH, and heat the area wider than the sheet passing area PW.

  The main valve 111 is formed so that the outer diameter of both end portions (main valve end portion 111a) in the width direction X is larger than the outer diameter of the central portion (main valve central portion 111b). Specifically, the main valve central portion 111b is formed so that the center in the width direction X is the thinnest and gradually becomes thicker toward the outside so as to be the same as the outer diameter of the main valve end portion 111a. . The main valve central portion 111b and the main valve end portion 111a are connected without providing a step or the like at the boundary. The sub valve 121 has the same shape as the main valve 111, and is formed such that the outer diameter of both end portions (sub valve end portion 121a) in the width direction X is larger than the outer diameter of the central portion (sub valve central portion 121b). Specifically, the main valve central portion 111b and the sub-valve central portion 121b have a length in the width direction X of 260 mm and an outer diameter of φ6.1 to 6.15 mm. The main valve end 111a and the sub valve end 121a have an outer diameter of 6.15 to 6.25 mm.

  The main lamp 110 and the sub lamp 120 are held by the insulator 61 to provide a contact region BS where the main valve end 111a and the sub valve end 121a are in contact with each other. As shown in FIG. 4A, the main valve end 111a and the sub valve end 121a are in contact with each other. On the other hand, as shown in FIG. 4B, the main valve central portion 111b and the sub-valve central portion 121b are separated from each other. In the present embodiment, the contact area BS is provided in the vicinity of the insulator 61, and a part thereof overlaps with the end of the heating area RH and the sheet passing area PW of the sub lamp 120. Accordingly, the contact area BS is a heating area RH of the sub lamp 120 and overlaps a portion (non-sheet passing heating area RK) that is outside the range of the sheet passing area PW. Note that the present invention is not limited to this, and the entire contact area BS may be provided outside the range of the sheet passing area PW, or may be a range that does not overlap with the non-sheet passing heating area RK.

  The central thermistor 91 a is provided at a position that is substantially in the center of the sheet passing area PW in the width direction X and that opposes the heating area RH of the main lamp 110. The end thermistor 91b is provided at the end of the sheet passing area PW and at a position facing the heating area RH of the sub lamp 120. The results detected by the central thermistor 91a and the end thermistor 91b are transmitted to the temperature control unit 203a (see FIG. 12 described later). In this embodiment, a non-contact thermistor is used as the central thermistor 91a and the end thermistor 91b. However, a contact thermistor may be used when detecting the temperature of the non-sheet passing region.

  When the halogen lamp is turned on, the filament becomes a high temperature of 2000 ° C. or higher and radiates radiation to heat the inner surface (particularly the heat absorption layer) of the heating roller 71, and the amount of heat generated in the vicinity of the heating region RH. Becomes larger. Since the glass tube absorbs a part of the radiation from the filament, it becomes a high temperature of 500 ° C. or more particularly in the vicinity of the heating region RH (main valve central portion 111b and sub-valve end portion 121a). The main valve end 111a and the sub-valve central part 121b) have a relatively low temperature. After the halogen lamp is turned off, radiation from the filament disappears, but radiation is radiated from the glass tube that has become hot. At this time, in the conventional configuration, the heating roller is heated by the radiation from the glass tube, and there is a possibility that an overshoot in which the temperature rises occurs.

  However, in the present embodiment, the main valve end 111a and the sub valve end 121a are in contact with each other, and the low temperature main valve end 111a is close to the high temperature sub valve end 121a. In general, the radiation from the filament has a peak at a wavelength of about 1 μm and is almost transmitted through the glass tube. On the other hand, the radiation from the glass tube having a high temperature of about 500 ° C. has a peak at a wavelength of about 3.5 μm, is hardly transmitted through the glass tube, and is absorbed by the adjacent low-temperature glass tube. That is, the radiation from the sub valve end 121a to the heating roller 71 is reduced by being blocked by the main valve end 111a, and the overshoot of the heating roller 71 is suppressed.

  Further, by bringing adjacent halogen lamps into contact with each other, heat transfer occurs through contact heat conduction through the end portions, and the amount of heat is dispersed. Thereby, overshoot due to local overheating of the halogen lamp can be prevented.

  Of the main lamp 110 and the sub lamp 120, the contact area BS overlaps with a part outside the sheet passing area PW (non-sheet passing area). By bringing the glass tube into contact in the non-sheet passing area and separating the glass tube in the sheet passing area PW, when the halogen lamp is started up, it is difficult for heat to be taken away by the adjacent halogen lamp. In addition, it is possible to achieve both overshoot suppression and shortening of the heating time.

  The overshoot in the non-sheet passing region is one of the major factors due to the sub-valve end 121a due to the sub-filament end 122a in the non-sheet passing heating region PK. Accordingly, the glass tubes of the main lamp 110 and the sub lamp 120 may be brought into contact with each other in a portion where the filament exists in the non-sheet passing region. In a structure using a halogen lamp, it is necessary to raise the temperature of the glass tube and generate a halogen cycle in the enclosed gas in order to shorten the start-up time and prevent the filament from deteriorating. Therefore, by setting the range in contact with the glass tube to the minimum necessary range, it is possible to prevent a local temperature rise while preventing excessive cooling and increasing the temperature of the glass tube.

  In the present embodiment, the plurality of halogen lamps are integrated by the insulator 61, so that both ends are in contact with each other while maintaining the distance between the halogen lamps. Further, by reducing the temperature of the end portion that seals the glass tube, breakage of the sealing portion can be prevented, and the halogen lamp can be used over a long period of time. Note that the insulator 61 may be provided with a slight gap (play) without completely fixing the main lamp 110 and the sub lamp 120 for convenience of manufacturing.

  Next, a modified example of the lamp unit 60 (two lamp structure 60a) will be described.

  FIG. 5 is a side view showing a modification of the lamp unit according to the first embodiment of the present invention.

  In the modification, a part of the filament is short-circuited with respect to the lamp unit 60 shown in FIG. 3 to reduce the heat generation amount. Specifically, the lamp part 60 (short-circuit lamp structure 60b) in the modification is substantially the same structure as the lamp part 60 (two lamp structure 60a) shown in FIG. 3, and the part other than the heating area RH is a low heat generation area. RT. In the low heat generation region RT, the filament is short-circuited to eliminate the substantial number of turns, and the heat generation amount is reduced to a level that can be ignored. In the main lamp 110, the main filament end 112a is a low heat generation region RT, and in the sub lamp 120, the subfilament central portion 122b is a low heat generation region RT. By providing the low heat generation region RT, it is possible to clearly distinguish a portion to be heated and a portion where temperature rise is desired to be suppressed as a partially heated halogen lamp. Note that the low heat generation region RT may be configured not only to short-circuit the filament but also to reduce the heat generation amount by reducing the number of windings per unit length.

(Second Embodiment)
FIG. 6 is a schematic cross-sectional view of a fixing device according to a second embodiment of the present invention. In addition, about the component which a function is substantially equal to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The second embodiment differs from the first embodiment in the heating member TB, and is configured to sandwich and convey the paper P by the pressure roller 40 and the heating roller 71. That is, in the first embodiment, the belt fixing method using the fixing belt 51 is used, whereas in the second embodiment, the roller fixing method in which the pressure roller 40 is pressed against the heating roller 71 is used. Yes.

  Specifically, in the fixing device 17 according to the second embodiment, the pressure roller 40, the heating roller 71, the lamp unit 60, two thermistors (a central thermistor 91 a and an end thermistor 91 b), a paper feed sensor 92, and a peeling claw 93. Since each structure is the same as that of the first embodiment, description thereof is omitted.

  The heating roller 71 is a heated portion HK into which the lamp unit 60 is inserted, and is a heating member TB that presses the paper P, and a fixing nip portion Nf is formed between the heating roller 71 and the pressure roller 40. The two thermistors are provided at positions facing the heating roller 71 and detect the temperature of the heating roller 71. The sheet passing sensor 92 is provided on the downstream side of the fixing nip portion Nf in the conveyance direction of the sheet P. The peeling claw 93 is provided so as to be close to the peripheral surface of the heating roller 71.

  7 is a side view showing a lamp portion of the fixing device according to the second embodiment of the present invention, FIG. 8A is a cross-sectional view taken along arrows CC in FIG. 7, and FIG. 7 is a cross-sectional view of arrow DD in FIG.

  The lamp unit 60 shown in FIG. 3 has two halogen lamps, whereas the lamp unit 60 shown in FIG. 7 has three halogen lamps. Specifically, the lamp unit 60 (three lamp structure 60 c) has a structure including an assist lamp 130 in addition to the main lamp 110 and the sub lamp 120.

  The glass tube (assist bulb 131) of the assist lamp 130 has the same shape as the main bulb 111 and the sub bulb 121, and the outer diameter of both ends (assist bulb end 131a) in the width direction X is the center (assist bulb). It is formed larger than the outer diameter of the central portion 131b). The filament of the assist lamp 130 (assist filament 132) has a uniform number of turns per unit length in the width direction X, and the amount of heat generated is constant. As shown in FIG. 8A, the assist valve end 131a is in contact with the main valve end 111a and the sub valve end 121a. Further, as shown in FIG. 8B, the assist valve central portion 131b is separated from the main valve central portion 111b and the sub-valve central portion 121b.

  The assist lamp 130 is turned on together with the main lamp 110 and the sub lamp 120 when the non-lighted halogen lamp is turned on at the time of initial start-up or when returning from the power saving setting, thereby shortening the start-up time. We are trying to make it. In addition, the assist lamp 130 may not be turned on during the sheet passing, and the main lamp 110 and the sub lamp 120 are turned on by suppressing the output so that the maximum allowable current of the image forming apparatus 1 is not exceeded. It may be used as an auxiliary heat source. That is, the temperature control unit 203a performs control so that one of the halogen lamps (particularly, the assist lamp 130) is not turned on or has a low output when fixing on the paper P. As a result, since the assist lamp 130 becomes low temperature during fixing, the heat transfer effect from the main lamp 110 and the sub lamp 120 can be promoted, and radiation from the glass tube can be shielded. Shooting can be further prevented. In order to prevent overshoot at the end of the lamp unit 60, the assist lamp 130 is preferably in contact with at least the glass tube of the sub lamp 120.

(Third embodiment)
FIG. 9 is a schematic cross-sectional view of a fixing device according to a third embodiment of the present invention. In addition, about the component which a function is substantially equal to 1st Embodiment and 2nd Embodiment, the same code is attached and description is abbreviate | omitted.

  The third embodiment is different from the second embodiment in the heating member TB, and is configured to sandwich and convey the paper P by the pressure roller 40 and the heating belt 52. That is, in the third embodiment, the heating belt 52 is used in place of the heating roller 71.

  Specifically, in the fixing device 17 according to the third embodiment, the pressure roller 40, the heating belt 52, the pressing roller 82, the ramp unit 60, two thermistors (a central thermistor 91a and an end thermistor 91b), a sheet passing sensor 92, In addition, since the structure includes the peeling claw 93 and the structure is the same as that of the first embodiment, the description thereof is omitted.

  The pressing roller 82 is a cylindrical roller and is made of the same material as the fixing roller 81, and has an outer diameter smaller than that of the fixing roller 81. The heating belt 52 is an endless belt, and an elastic layer made of silicone rubber and a surface layer made of fluororesin are provided on the surface of a metal sleeve made of Ni, Cu, SUS or the like. Inside the heating belt 52, a lamp portion 60 and a pressing roller 82 are disposed. The pressure roller 82 is pressed against the pressure roller 40 via the heating belt 52 and is driven according to the pressure roller 40, and a fixing nip portion Nf is formed between the pressure roller 40 and the pressure roller 40. The lamp unit 60 heats the inner surface of the heating belt 52. That is, in the third embodiment, the heating belt 52 corresponds to the heating member TB and the heated part HK.

  The two thermistors are provided at positions facing the heating belt 52 and detect the temperature of the heating belt 52. The sheet passing sensor 92 is provided on the downstream side of the fixing nip portion Nf in the conveyance direction of the sheet P. The peeling claw 93 is provided so as to be close to the peripheral surface of the heating belt 52.

  In the present embodiment, the distance from the main lamp 110 and the distance from the sub lamp 120 are equal to the heating belt 52, or the distance from the main lamp 110 is shorter than the distance from the sub lamp 120. It is desirable that they are arranged as follows. Since the elastic layer of the heating belt 52 is inferior in heat resistance, there is a possibility that problems such as peeling between layers occur in a non-sheet passing region where overshoot is likely to occur. Therefore, in the present embodiment, the sub lamp 120 is disposed at a position farther from the elastic layer than the main lamp 110, thereby suppressing overshoot in the non-sheet passing region.

  In the first embodiment described above, a regulating member is applied to the end portion of the fixing belt 51 to suppress the movement (meandering) of the fixing belt 51 in the width direction X. Here, when polyimide is used as the base material of the fixing belt 51, there is a concern that the base material softens due to heating by overshoot, and the meandering fixing belt 51 gets over the regulating member. In order to solve such a problem, it is desirable to dispose the sub lamp 120 at a position farther from the inner surface of the fixing belt 51 than the main lamp 110.

(Fourth embodiment)
FIG. 10 is a schematic cross-sectional view of a fixing device according to a fourth embodiment of the present invention. In addition, about the component which a function is substantially equal to 1st Embodiment thru | or 3rd Embodiment, the same code is attached and description is abbreviate | omitted.

  The fourth embodiment has a structure in which a pressing pad 83 is used instead of the pressing roller 82 as compared with the third embodiment. The other members are the same as those in the third embodiment, and a description thereof will be omitted.

  The pressure pad 83 is formed in a long plate shape extending in the width direction X, and is pressed against the pressure roller 40 via the heating belt 52, and a fixing nip portion Nf is formed between the pressure pad 40 and the pressure pad 40. The The pressing pad 83 is configured not to be driven regardless of the rotation of the pressure roller 40 and the heating belt 52, and the same portion contacts the heating belt 52. Therefore, the surface of the pressing pad 83 that contacts the heating belt 52 may be a curved surface so as not to hinder the rotation of the heating belt 52.

  As described above, as the lamp unit 60, the three structures of the two lamp structure 60a, the short lamp structure 60b, and the three lamp structure 60c have been described. However, the fixing device 17 according to the first to fourth embodiments is described. Then, any structure may be applied. In the image forming apparatus 1, any fixing device 17 among the fixing devices 17 according to the first to fourth embodiments may be applied.

  Next, temperature control when continuously fixing a plurality of sheets will be described with reference to the drawings.

  FIG. 11 is a characteristic diagram showing a temperature change of the heating member during fixing.

  FIG. 11 shows the temperature change of the heating member TB with time, and the measured temperature BT shows the temperature of the heating member TB detected by the thermistor. In the image forming apparatus 1, the output of the lamp unit 60 is controlled by the temperature control unit 203a so that the heating member TB becomes a preset fixing temperature ST. For example, ON / OFF control, duty control, phase control, and wave number control can be used as the output control method. Below, the control in the case of performing continuous paper feeding from the standby mode in which the heating member TB is held stationary will be described. During the continuous paper passing period, the paper P to be fixed last (hereinafter, sometimes referred to as the final paper for explanation) is excluded from the time when an instruction to execute image formation is received (time T1). Until the time when the sheet is discharged to the paper tray 19 (time T2), after that, the standby mode is set and the next image forming instruction is awaited.

  In FIG. 11, the standby mode is set at the start, the fixing temperature ST is set to a low temperature K1 (standby temperature), and the measured temperature BT also changes in the vicinity of the temperature K1. The heating member TB is kept warm so as to maintain a standby temperature lower than that at the time of fixing before or after the sheet P is passed. That is, by keeping the heating member TB warm, it is possible to shorten the time required for the temperature rise during fixing. The temperature K1 is set to 160 ° C., for example.

  At time T1, upon receiving an instruction to execute image formation, the temperature control unit 203a sets the fixing temperature ST to a high temperature K2 (paper passing temperature). By increasing the setting of the fixing temperature ST and increasing the output of the lamp unit 60, the heating member TB is heated, and the measured temperature BT changes in the vicinity after reaching the temperature K2. The temperature K2 is set to 170 ° C., for example.

  At time Td, the paper passing sensor 92 detects that the leading edge of the paper P to be fixed last passes through the fixing nip portion Nf. Here, the temperature control unit 203a changes the setting of the fixing temperature ST to the low temperature K1. By reducing the setting of the fixing temperature ST, the output of the lamp unit 60 decreases, and the measured temperature BT decreases so as to approach the temperature K1.

  At time T <b> 2, the trailing edge of the paper P to be finally fixed passes through the fixing nip portion Nf and is discharged to the paper discharge tray 19. When the sheet P finishes passing through the fixing nip portion Nf, the heating member TB is heated by the heat supplied to the sheet P. As a result, the actually measured temperature BT that has approached the low temperature K1 temporarily increases and then decreases so as to approach the temperature K1 again.

  Conventionally, the fixing temperature ST is maintained at the high temperature K2 until the paper P is discharged, as indicated by the alternate long and short dash line in FIG. Then, since the heating member TB is heated after the paper P is discharged, the actually measured temperature BT further rises from the temperature K2 and overshoots. That is, since the amount of heat is applied to the sheet P during fixing, the amount of heat from the halogen lamp is dispersed, but when the sheet P runs out, the amount of heat concentrates on the heating member TB and the temperature rises rapidly. However, in the present invention, during the temperature change time ΔT from the time Td to the time T2, by lowering the setting of the fixing temperature ST, the lighting of the halogen lamp is suppressed, the temperature rise becomes moderate, and the fixing is completed. Overshoot can be prevented.

  As shown in FIG. 11, the temperature change time ΔT is set to the same temperature K1 as in the standby mode, but may be set to a different temperature, and is set to a temperature lower than the fixing temperature K2 (suppression temperature). Just do it. That is, the suppression temperature may be set to be different from the standby temperature. If the temperature is set to the same temperature as the standby mode, it is not necessary to store a plurality of temperatures.

  In addition, the time Td when the leading edge of the paper P to be fixed last passes through the fixing nip portion Nf is set as the timing (temperature change timing) for lowering the setting of the fixing temperature ST. However, the present invention is not limited to this. It may be the timing when P passes through the fixing nip portion Nf. Furthermore, a paper detection sensor may be provided upstream of the fixing nip portion Nf, and the timing before the setting of the fixing temperature ST may be lowered before the paper P passes through the fixing nip portion Nf. When changing the timing for lowering the setting of the fixing temperature ST, the temperature change time ΔT and the like may be changed.

  Further, the temperature control unit 203a may perform control so as to lower the setting of the fixing temperature ST based on the number of sheets P to be continuously fixed. That is, as the time for fixing increases, the temperature of the halogen lamp tends to increase. Therefore, it is desirable to control the setting of the fixing temperature ST according to the number of sheets to be fixed.

  Further, the temperature control unit 203a may perform control so as to lower the setting of the fixing temperature ST based on the type of the paper P to be fixed. That is, the thickness and size differ depending on the type of paper P, and the output of the lamp unit 60 is adjusted to change the degree of temperature rise. Therefore, it is desirable to control the setting of the fixing temperature ST according to each.

  Further, an environmental temperature detection sensor that detects the temperature of the environment in which the image forming apparatus 1 is installed as the environmental temperature may be provided. Then, the temperature control unit 203a performs control so as to lower the setting of the fixing temperature ST based on the environmental temperature. That is, since the degree to which the temperature rises changes depending on the installed environment, it is desirable to control the setting of the fixing temperature ST according to the environmental temperature.

  FIG. 12 is a schematic configuration diagram illustrating an image forming apparatus and a server connected to the cloud service.

  As shown in FIG. 12, a plurality of image forming apparatuses 1 and a server 300 are connected to the network 400. The image forming apparatus 1 includes an image forming unit 201, a fixing device 17, a temperature detection unit 202, a communication unit 205, a CPU 203, and a storage device 204. The image forming unit 201 is a part that forms an image on the paper P, such as the intermediate transfer belt device 16 and the secondary transfer device 26. The temperature detection unit 202 includes a central thermistor 91a, an end thermistor 91b, an environmental temperature detection sensor, and the like, and detects the temperature related to the image forming apparatus 1. The communication unit 205 is connected to the external server 300 via the network 400 and transmits / receives information. The CPU 203 stores the temperature control unit 203a and the history storage unit 203b as preinstalled programs, and executes the processing described later by executing the stored programs. The fixing device 17 may be controlled by the CPU 203. That is, the CPU 203 common to the image forming apparatus 1 and the fixing device 17 may be used. The storage device 204 stores information transmitted and received by the communication unit 205.

  The server 300 includes a server communication unit 301, a server storage device 302, and a CPU 303. The server communication unit 301 and the server storage device 302 are substantially the same as the communication unit 205 and the storage device 204 in the image forming apparatus 1, and transmit and receive information and store them. The CPU 303 stores the information storage unit 303a and the setting calculation unit 303b as preinstalled programs, and executes the processing described later by executing the stored program.

  In the image forming apparatus 1, it is desirable that the temperature change timing and the suppression temperature are optimized so as to ensure the image quality of fixing at the trailing edge of the final sheet. Further, the contact state between the halogen lamps varies depending on the image forming apparatus 1 and can be further stabilized by linking with the control.

  Therefore, in the image forming apparatus 1, the history accumulating unit 203b includes the heating member TB based on the history of the actually measured temperature BT detected by the temperature detecting unit 202 (temperature history information) and the temperature difference between the central thermistor 91a and the end thermistor 91b. Temperature storage (temperature distribution information), temperature detected by the environmental temperature sensor (environment temperature information), and the like are stored in the storage device 204. Information stored in the storage device 204 is sent to the server 300 by the communication unit 205.

  In the server 300, the received information is stored in the server storage device 302 by the information storage unit 303a. Based on the information stored in the server storage device 302, the setting calculation unit 303b calculates an appropriate temperature change timing and suppression temperature according to the situation, and transmits them to the image forming apparatus 1. In the image forming apparatus 1, the accumulated information is fed back to the temperature control, for example, the temperature change timing and the suppression temperature are changed based on the information calculated by the server 300. As described above, the image forming apparatus 1 is connected to the cloud service, and various information is provided from the server 300 via the network 400, and the provided information is reflected in temperature control and the like. The server 300 accumulates information transmitted from a plurality of image forming apparatuses 1 and provides a control method according to each image forming apparatus 1 to construct a system that optimizes temperature control. can do.

  It should be noted that the embodiment disclosed herein is illustrative in all respects and does not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiment, but is defined based on the description of the scope of claims. Moreover, all the changes within the meaning and range equivalent to a claim are included.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 17 Fixing apparatus 40 Pressure roller (an example of a pressure member)
51 Fixing Belt 60 Lamp Unit 61 Insulator 62 Lead Wire 71 Heating Roller 81 Fixing Roller 91a Central Thermistor 91b End Thermistor 92 Paper Feed Sensor 93 Peeling Claw 110 Main Lamp 111 Main Valve 111a Main Valve End 111b Main Valve Center 112 Main Filament 112a Main filament end portion 112b Main filament central portion 120 Sub lamp 121 Sub bulb 121a Sub bulb end portion 121b Sub bulb central portion 122 Sub filament 112a Sub filament end portion 112b Sub filament central portion BS Contact area HK Heated part PW Paper passing area RH Heating area RK Non-paper heating area RT Low heat generation area TB Heating member X Width direction

Claims (14)

A heating member and a pressure member that are rotatably provided, a lamp unit that heats the heating member, a temperature detection unit that detects the temperature of the heating member, and a temperature control unit that controls electric power supplied to the lamp unit And the sheet is inserted between the heating member and the pressure member, and the unfixed toner image on the sheet is heated and pressurized to be fixed on the sheet. A fixing device,
When the direction along the width of the paper being transported is the width direction,
The lamp portion heats the central portion of the heating member in the width direction, and includes a first lamp having a glass tube and a filament,
A second lamp having a glass tube and a filament for heating the end in the width direction of the heating member;
The first lamp and the second lamp are formed such that an outer diameter of both end portions in the width direction of the glass tube is larger than an outer diameter of a central portion, and the glass tubes are arranged close to each other. The fixing device is arranged so that the glass tubes are brought into contact with each other at both ends in the width direction. The fixing device according to claim 1,
Of the first lamp and the second lamp, the area where the glass tubes are in contact with each other is the largest in the width direction of the paper conveyed by the heating member and the pressure member. A fixing device including a non-sheet passing area on a certain sheet. The fixing device according to claim 1 or 2, wherein
The first lamp and the second lamp are in a non-sheet passing region with respect to the width direction, and the glass tubes are in contact with each other in a region where the filament is present. A fixing device. A fixing device according to any one of claims 1 to 3, wherein
The temperature control unit sets the temperature of the heating member heated by the lamp unit to a sheet temperature when fixing a plurality of sheets continuously, and maintains the sheet passing temperature. The power to be supplied to the printing unit is controlled, and the fixing temperature is set lower than the sheet passing temperature before the paper to be fixed last passes through the nip where the heating member and the pressure member abut. A fixing device characterized in that the temperature is set. The fixing device according to claim 4,
The temperature control unit sets a standby temperature that is lower than the sheet passing temperature in order to maintain the heating member at a predetermined temperature before and after passing the sheet. A fixing temperature is set to the standby temperature before a sheet to be fixed last passes through a nip portion where the heating member and the pressure member are in contact with each other. . The fixing device according to claim 4 or 5, wherein:
The temperature control unit is configured to control the heating member according to the number of passing sheets information based on the number of sheets to be fixed continuously, the sheet information based on the type of sheets to be fixed, or the environment information based on the installed environment. A fixing device, characterized in that the set temperature is lowered and the set temperature is changed. A fixing device according to any one of claims 1 to 6, wherein
Including the heating member including an elastic layer formed of at least silicone rubber;
The distance from the first lamp and the distance from the second lamp are equal to the inner region of the heating member that can heat the elastic layer by radiant heat of the lamp portion and heat conduction in the thickness direction, or The fixing device is characterized in that a distance from the first lamp is shorter than a distance from the second lamp. A fixing device according to any one of claims 1 to 7,
The heating member is made of a metal having a fixing layer having a surface layer made of fluororesin, an elastic layer made of silicone rubber, and a base material made of polyimide resin, and the lamp portion provided therein. A cylindrical roller, and a distance from the first lamp and a distance from the second lamp are equal to an inner region of a portion of the metal cylindrical roller wound around the fixing belt, or A fixing device characterized in that the distance from the first lamp is shorter than the distance from the second lamp. A fixing device according to any one of claims 1 to 8, wherein
The first lamp and the second lamp are supported so as to maintain a predetermined interval by an insulator provided on each one of both ends in the width direction so that the respective glass tubes are in contact with each other. A fixing device. A fixing device according to any one of claims 1 to 9, wherein
The fixing device, wherein the first lamp has a filament short-circuited at least in a region facing the filament of the second lamp existing in the non-sheet passing region. A fixing device according to any one of claims 1 to 10, wherein
A third lamp for heating the heating member;
The fixing device, wherein the third lamp is capable of contacting at least a glass tube of the second lamp.   An image forming apparatus comprising the fixing device according to any one of claims 1 to 11. The image forming apparatus according to claim 12,
An image forming device that can be connected to a cloud service. The image forming apparatus according to claim 13,
An image forming apparatus, characterized in that a temperature setting and a timing for lowering the temperature setting and temperature change information are collected, and the temperature setting and the timing for lowering the temperature setting can be fed back through a cloud service.

Images