JP6919834B2 - Fixing device and image forming device - Google Patents

Description

The present invention relates to a fixing device and an image forming device.

Conventionally, a rotating body, a contact member that contacts the outer peripheral surface of the rotating body, a nip forming member that is arranged inside the rotating body and contacts the contact member via the rotating body to form a nip portion, and a nip forming member. A fixing device including a stay supporting the stay, a heating element arranged inside the rotating body, and holding means for holding both ends in the width direction orthogonal to the surface moving direction of the rotating body of the stay is known. .. Further, a reflecting member for reflecting the radiant heat radiated from the heating element on the reflecting surface is provided, and both ends of the reflecting member in the width direction are attached to the stay by the attaching member.

In Patent Document 1, the fixing device is provided as a fixing device so as to face the inner peripheral surface of the fixing belt which is a rotating body at a position other than the nip portion, and is heated by the radiant heat of the heating element to heat the fixing belt. Those provided with metal members are described. Further, in this fixing device, a metal member, a heating element and a stay are held by the side plate through a side plate serving as a holding means. Then, the reflective member is attached to the stay by a screw as an attachment member on the outer side of the widthwise end of the metal member penetrating the side plate, that is, on the outer side in the width direction of the side plate.

However, in the configuration described in Patent Document 1, there is a problem that the assembling property is poor.

In order to solve the above-mentioned problems, the present invention presents a rotating body, a contact member that contacts the outer peripheral surface of the rotating body, and a contact member that is arranged inside the rotating body and comes into contact with the contact member via the rotating body. The nip forming member forming the nip portion, the stay supporting the nip forming member, the heating element arranged inside the rotating body, and both ends of the stay in the width direction orthogonal to the surface moving direction of the rotating body. A fixing device including a holding means for holding each and a reflecting member for reflecting radiant heat radiated from the heating element on a reflecting surface, and both ends of the reflecting member in the width direction are attached to the stay by the attaching member. The present invention is characterized in that the position of attaching the reflective member to the stay is arranged outside the end portion of the heat generating portion of the heating element and closer to the center side than the holding means in the width direction. Is.

According to the present invention, the reflective member and the stay can be easily assembled.

The schematic block diagram of the copying machine which concerns on embodiment. The schematic block diagram of the fixing device which concerns on embodiment. Schematic diagram of a fixing device having a chevron shape on a reflector. A perspective explanatory view of the fixing device. Schematic diagram of the top surface of the fixing device, (a) is for non-pressure welding, and (b) is for pressure welding. The schematic block diagram of the fixing device which has an arc shape in a reflector. The schematic block diagram of the fixing device which has a valley shape in a reflector. The perspective explanatory view of the fixing device of the comparative example. Schematic cross-sectional view of the fixing point of the reflector of the fixing device of the comparative example, (a) is the fixing point by the flat head screw, and (b) is the fixing place by the stepped screw. Schematic diagram of the upper surface of the fixing device of the comparative example, (a) is at the time of non-pressure welding, and (b) is at the time of pressure welding. Explanatory drawing about movement of a reflector at the time of pressure roller pressure welding of the fixing device of a comparative example. The perspective view which shows the support side plate. An exploded perspective view showing a stay member, a support side plate, and a connecting plate. An enlarged perspective view of a portion surrounded by a broken line H in FIG. The perspective view which shows the stay member, the support side plate, and the connecting plate. An enlarged perspective view showing a state in which the stay member is assembled to the support side plate. The figure which shows the detailed structure of the 1st halogen heater and the 2nd halogen heater. The figure which shows an example of the structure of the non-heat-generating region on the end side of the heat-generating region of the second halogen heater. The reflective surface of the reflector has two parallel and stepped flat surfaces and an inclined flat surface connecting the two flat surfaces as a shape that reflects the radiant heat in a direction different from the direction in which the radiant heat is incident. Schematic block diagram of the fixing device. (A) is a schematic configuration diagram showing the vicinity of the reflector fixing portion on one end side in the longitudinal direction in the modified example, and (b) is a schematic configuration diagram showing the vicinity of the reflector fixing portion on the other end side in the longitudinal direction in the modified example. .. (A) is a schematic cross-sectional view showing the vicinity of the reflector fixing portion on one end side in the longitudinal direction in the modified example, (b) is a view seen from the C1 direction of FIG. 21 (a), and (c) is a view. FIG. 21 (a) is a view seen from the C2 direction. The figure explaining the attachment position of a reflector to a stay member. The figure which shows the example which attaches the reflector to the stay member at two places in the lateral direction.

Hereinafter, an embodiment of an electrophotographic image forming apparatus including a fixing apparatus to which the present invention is applied will be described.

FIG. 1 is a schematic configuration diagram of a copying machine 500, which is an image forming apparatus according to the present embodiment.
The copying machine 500 includes an image forming unit 200, a paper feeding unit 400 arranged below the image forming unit 200, and a scanner unit 300 arranged above the image forming unit 200.

The image forming unit 200 includes four image forming devices 1 (Y, M, C, K) corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K). Y, M, C, and K added after the numbers of each code indicate that the members are for yellow, magenta, cyan, and black (the same applies hereinafter). The four image forming devices 1 (Y, M, C, K) have almost the same configuration except that the colors of the toners they handle are different. Therefore, "Y" indicating the color of the toner to be used is described below. , "M", "C", and "K" are omitted as appropriate.

The image forming apparatus 1 includes a photoconductor 3 as an image carrier, a charging device 2 for charging the surface of the photoconductor 3, a developing device 5 as a developing means, and a cleaning device 7 for cleaning the photoconductor 3.

The image forming unit 200 includes a writing unit 100 for writing an electrostatic latent image on the photoconductor 3, an intermediate transfer belt 16 on which a toner image formed on the photoconductor 3 is transferred, and four photoconductors 3. It is provided with four primary transfer rollers 6 for primary transfer of the toner image to the intermediate transfer belt 16, respectively. Further, a secondary transfer roller 26 is provided which forms a secondary transfer nip facing the intermediate transfer belt 16 and transfers the toner image on the intermediate transfer belt 16 to the transfer paper S as a recording material. A resist roller pair 12 for temporarily holding the transfer paper S on standby is provided on the upstream side of the transfer paper S in the transport direction with respect to the secondary transfer nip.

The image forming unit 200 includes four toner bottles 20 (Y, M, C, K) for storing replenishment toner to be replenished in each of the developing devices 5 (Y, M, C, K) that consume toner. Further, a fixing device 9 as a fixing means is provided above the secondary transfer roller 26, and a paper ejection roller 18 is provided on the downstream side of the fixing device 9 in the transport direction of the transfer paper S.

The paper feed unit 400 has a paper feed cassette 10 and a paper feed roller 11 which are recording material storage units, and the paper feed cassette 10 loads the transfer paper S on the loading surface. The paper feed roller 11 is for separately feeding the transfer paper S loaded on the paper feed cassette 10 one by one.

The scanner unit 300 includes a contact glass 31 on which a document is placed. Further, in order to read and scan the document placed on the contact glass 31, the first traveling body 32 provided with the document illumination light source 32a and the first mirror 32b, and the second mirror 35a and the third mirror 35b are provided. The second traveling body 35 provided is provided. Further, it includes a lens 33 and a CCD (CCD image sensor) 34 installed behind the lens 33.

Next, the operation of image formation of the copying machine 500 will be described.
When the document is placed on the contact glass 31 and the image forming operation is started, the light source 32a for illuminating the document irradiates the light, and the reflected light reflected by the document is the first mirror 32b, the second mirror 35a, and the third mirror. It is reflected by the mirror 35b, imaged by the lens 33, and incident on the CCD 34. The scanner unit 300 generates image information to be formed on the transfer paper S based on the light incident on the CCD 34.

In the image forming unit 200, the rotating photoconductor 3 is uniformly charged by the charging device 2, and the writing unit 100 is driven based on the above-mentioned image information. The writing unit 100 emits irradiation light from a light source based on image information and scans the surface of the uniformly charged photoconductor 3 to form an electrostatic latent image on the photoconductor 3. The electrostatic latent image is developed by supplying a developer (toner) from the developing roller 15 of the developing apparatus 5, and becomes a toner image as a visible image.

On the other hand, while the toner image is being formed on the photoconductor 3, the transfer paper S is pulled out from the selected one of the plurality of paper cassettes 10 by the paper feed roller 11, and the tip thereof is resisted. It stands by in contact with the nip portion of the roller pair 12. Then, the resist roller pair 12 starts rotating at the timing of superimposing the transfer paper S on the toner image on the intermediate transfer belt 16 on which the toner images of each color are superposed and transferred by the four primary transfer nips, so that the transfer is performed. Paper S is fed to the secondary transfer nip. The transfer paper S on which the toner image is transferred by the secondary transfer nip is statically eliminated by contact with the static elimination brush, mechanically separated from the intermediate transfer belt 16, and then sent to the fixing device 9.

In the fixing device 9, the transfer paper S is heated and pressurized to fix the toner image on the transfer paper S. The transfer paper S on which the toner image has been fixed after passing through the fixing device 9 is discharged onto the paper ejection tray 8 by the paper ejection roller 18.
The transfer residual toner remaining on the surface of the photoconductor 3 after passing through the primary transfer nip is removed from the photoconductor 3 by the cleaning device 7 and recovered. The surface of the photoconductor 3 from which the transfer residual toner has been recovered is statically eliminated by the static elimination device to prepare for the next image forming step.

In the above description, the image forming operation in which the image information of the document is read by the scanner unit 300 and the image is created based on the image information has been described. The copier 500 can also create an image based on image information input from an external electronic device such as a personal computer.

The copying machine 500, which is the image forming apparatus of the embodiment, is an intermediate transfer method in which the toner image on the photoconductor 3 is transferred to the transfer paper S via the intermediate transfer belt 16 which is an intermediate transfer body. The method of transferring the toner image to the transfer paper S is not limited to the intermediate transfer method, and may be a direct method of transferring the toner image directly from the photoconductor to the transfer paper S.

FIG. 2 is a schematic configuration diagram of the fixing device 9 according to the present embodiment.
The fixing device 9 is provided with a pressure roller 30 which is a contact member that is rotationally driven, and a fixing belt 38 which is a substantially cylindrical fixing member. Inside the cylindrical fixing belt 38, a pressure pad 60 and a stay member 61 constituting a nip forming member, and a first halogen heater 50a and a second halogen heater 50b as a plurality of heating elements are provided. There is.

As shown in FIG. 2, the first halogen heater 50a and the second halogen heater 50b are arranged on both sides in the vertical direction with the stay member 61 interposed therebetween.
Further, between the two halogen heaters 50 and the stay member 61, a reflector 40 that reflects the radiant heat radiated from the halogen heater 50 toward the inner peripheral surface of the fixing belt 38 is arranged.
Further, at both ends of the fixing device 9 in the longitudinal direction (direction orthogonal to the paper surface in FIG. 2), a support that is a part of the structure of the copying machine 500 and supports the constituent members of the fixing device 9 described above is supported. It has a side plate 70.

The fixing belt 38 is a cylindrical heating rotating body that can be flexibly deformed. A base made of nickel (Ni) having a cylindrical outer shape of 30 [mm] and a thickness of 10 to 70 [μm], and this base. It has an elastic layer coated on the surface. The elastic layer is made of silicone rubber and has a thickness of 50 to 150 [μm].
A mold release layer made of a fluororesin having a thickness of 5 to 50 [μm] is formed on the outermost surface layer of the fixing belt 38 in order to enhance durability and ensure mold releasability. Examples of the fluororesin include, but are not limited to, PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) and PTFE (polytetrafluoroethylene).
Further, the fixing belt substrate is not limited to nickel, and may be a metal substrate such as SUS (stainless steel) or a heat-resistant resin such as PI (polyimide).

The pressure roller 30 has an outer diameter of 30 [mm], and is formed of a hollow iron core metal 30a, an elastic layer 30b formed on the surface of the iron core metal 30a, and a release layer 30c.
The elastic layer 30b is made of silicone rubber and has a thickness of 5 [mm]. It is desirable to form a mold release layer 30c made of a fluororesin having a thickness of about 40 [μm] on the surface of the elastic layer 30b in order to improve the mold release property. The pressure roller 30 is urged toward the fixing belt 38 by the urging means, and the pressure roller 30 and the fixing belt 38 are in pressure contact with each other.

The pressure pad 60 covers the resin portion 60a made of a resin material having high heat resistance such as LCP (liquid crystal polymer) and the resin portion 60a and is in sliding contact with the inner surface of the fixing belt 38, and the temperature in the longitudinal direction of the fixing belt 38. It is formed of a copper soaking portion 60b that makes the distribution uniform. The pressure pad 60 sandwiches the fixing belt 38 and is in pressure contact with the pressure roller 30 to form a fixing nip SN.
Further, the pressure pad 60 is supported by a stay member 61 which is a reinforcing portion for reinforcing the pressure pad 60 from the inside. Both ends of the stay member 61 in the longitudinal direction are supported by the support side plates 70, and the stay member 61 receives the pressing pressure of the pressurizing roller 30 against the pressurizing pad 60 to form the fixing nip SN.

The two halogen heaters 50 (a, b) are arranged on both sides in the vertical direction with the stay member 61 interposed therebetween, and both ends in the longitudinal direction are supported by heater folders located outside the support side plate 70 in the longitudinal direction.
In the first halogen heater 50a, the first light emitting portion filament 51a is arranged in the longitudinal direction in a narrow region corresponding to the width of the small-sized transfer paper S. In the second halogen heater 50b, the second light emitting portion filament 51b is arranged in the longitudinal direction in a region outside the width of the small size transfer paper S in the wide region corresponding to the width of the large size transfer paper S.

The reflector 40 is arranged at a position where the halogen heater 50 and the stay member 61 face each other, and both ends in the longitudinal direction are supported by the stay member 61 via stepped screws 43 described later. The reflector 40 is formed of an aluminum substrate and a silver paste applied to the surface of the substrate, and reflects the radiant heat of the halogen heater 50 toward the fixing belt 38 on the reflecting surface 40f. The reflector 40 has a shape in which a plurality of plate-shaped members are bent and bent so as to block between the stay member 61, the pressure pad 60, and the halogen heater 50.

FIG. 3 is a schematic configuration diagram of a fixing device 9 having a chevron shape 46 as a shape that reflects radiant heat in a direction different from the direction in which radiant heat is incident on the reflecting surface 40f of the reflector 40.
Since they are common except that the shape of the portion of the reflector 40 facing the halogen heater 50 is different, only the differences will be described.

In the fixing device shown in FIG. 3, a mountain-shaped shape 46 having this position as an apex 41 is formed at a position where the perpendicular line drawn from the center of the halogen heater 50 to the reflecting surface 40f of the reflector 40 and the reflecting surface 40f intersect. .. By providing such a chevron shape 46, among the radiant heat radiated from the halogen heater 50, the radiant heat incident on the reflection surface 40f along the vertical line is incident on the slope of the chevron shape 46. At this time, since the incident direction of the radiant heat and the slope of the mountain-shaped shape 46 are not at right angles, the radiant heat is reflected in a direction different from the incident direction. Therefore, the radiant heat incident on the reflecting surface 40f can be reflected toward the fixing belt 38 while avoiding the passage of the halogen heater 50, and the radiant heat can be prevented from heating the halogen heater 50 itself.

FIG. 12 is a perspective view showing the support side plate 70.
The support side plate 70 serving as the holding means is provided with a fitting hole 70b into which the stay member 61 is fitted and a through hole 70a through which the halogen heater 50 penetrates. Further, 70c is a connecting plate mounting portion to which a connecting plate 72 for connecting the support side plate 70 on one end side in the axial direction and the support side plate 70 on the other end side is attached.

FIG. 13 is an exploded perspective view showing the stay member 61, the support side plate 70, and the connecting plate 72, and FIG. 14 is an enlarged perspective view of a portion surrounded by the broken line H in FIG. Further, FIG. 15 is a perspective view showing the stay member 61, the support side plate 70, and the connecting plate 72, and FIG. 16 is an enlarged perspective view showing a state in which the stay member 61 is assembled to the support side plate 70.
Steps are formed at both ends of the stay member 61 in the longitudinal direction (Y direction in the drawing), and a fitting portion 61a that fits into the fitting hole 70b of the support side plate 70 and an abutting portion 61b that abuts against the support side plate 70 are provided. There is.

61e and 61d shown in FIG. 16 are screw holes for screwing the reflector 40, and 61e is a reflector 40 provided on the second surface which is the lower surface (the surface on the upstream side in the paper transport direction) of the stay member 61. It is a screw hole for screwing, and 61d is a screw hole for screwing the reflector 40 provided on the first surface which is the upper surface (the surface on the downstream side in the paper transport direction) of the stay member 61. The attachment of the reflector 40 to the stay member 61 will be described later.

To assemble the stay member 61, first, the fitting portion 61a on one end side is inserted into the fitting hole 70b until the abutting portion 61b on one end side of the stay member 61 abuts on the support side plate 70 on one end side. Next, the fitting hole 70b of the support side plate 70 on the other end side is fitted into the fitting portion 61a until the abutting portion 61b on the other end side of the stay member 61 abuts on the support side plate 70 on the other end side. Then, one end side of the connecting plate 72 is screwed to the support side plate 70 on one end side, and the other end side of the connecting plate 72 is screwed to the support side plate 70 on the other end side, as shown in FIG. The stay member 61 is positioned and fixed to the two support side plates 70.

FIG. 17 is a diagram showing a detailed configuration of the first halogen heater 50a and the second halogen heater 50b.
The first and second halogen heaters 50a and 50b are provided with a filament 505 made of tungsten or the like in a cylindrical glass tube made of quartz glass or the like. Further, in the glass tube, an annular supporter 503 is provided in order to maintain the shape of the filament 505. The supporter 503 is made of tungsten or the like.

The second halogen heater 50b has a non-heating region 502 at the center in the longitudinal direction and a heat generating region 501 at both ends in the longitudinal direction. On the other hand, in the first halogen heater 50a, the central portion in the longitudinal direction is the heat generating region 501, and both end portions in the longitudinal direction are the non-heating regions 502. Filaments 505 are spirally and densely wound around the heat generating regions 501 of the halogen heaters 50a and 50b to form light emitting portion filaments 51a and 51b as heat generating portions.

In the non-heating region 502 of the second halogen heater 50b, the filament 505 is formed in a substantially linear shape. However, in the place where the supporter 503 is arranged, it is tightly wound around the supporter 503. The portion of the filament 505 that is tightly wound around the supporter 503 is called a "discard winding" and is a portion that is held by the supporter 503.

On the other hand, in the non-heating region 502 of the first halogen heater 50a, a short-circuit core rod 504 made of a metal material such as molybdenum is provided, and the filament 505 is wound around the short-circuit core rod 504. Further, in the non-heating region 502, the filament 505 is densely wound around the supporters 503 provided at both ends of the short-circuit core rod 504.

As described above, the first halogen heater 50a and the second halogen heater 50b are significantly different in whether or not there is a short-circuit core rod 504 in the non-heating region 502. By providing the short-circuit core rod 504 in the non-heating region 502, it is possible to suppress heat generation in the tightly wound portion of the filament 505 in the non-heating region 502. That is, in the non-heating region 502 of the first halogen heater 50a, since the short-circuit core rod 504 is provided, the electric resistance in the tightly wound portion (discarded winding) wound around the supporter 503 of the filament 505 is reduced. Heat generation is suppressed as compared with the tightly wound portion (discarded winding) of the non-heating region 502 of the second halogen heater 50b.

In this way, by providing the short-circuit core rod 504 in the non-heating region 502 of the first halogen heater 50a, it is possible to suppress partial heat generation on the end side. As a result, the temperature of the fixing belt 38 is less likely to vary, and the temperature controllability is improved. Further, in the first halogen heater 50a, unnecessary heat generation in the non-heat generation region 502 can be suppressed, so that the heater power consumption can be reduced, and when the lighting equipment or the like is connected to the common power supply system with the heater. It is possible to suppress possible flicker (flickering phenomenon). Further, flicker is likely to occur not only by increasing the power consumption of the heater but also by shortening the control cycle (lighting cycle) of the heater. However, in the present embodiment, the power consumption of the heater can be reduced by the amount of the heater. Since the control cycle can be shortened, the temperature controllability is improved.

Further, as shown in FIG. 18, the supporter 503 is also arranged in the non-heating region on the end side of the heat generating region 501 of the second halogen heater 50b, and when it has a tightly wound portion, it is short-circuited in the non-heating region on the end side. It is preferable to arrange the core rod 504.

Here, the conventional fixing device will be described.
In image forming devices such as copiers, printers, and facsimiles, a toner image is formed on an image carrier based on image information, and the toner image is transferred onto a recording material such as paper or an OHP sheet to transfer the toner image. The carried recording material is passed through a fixing device, and the toner image is fixed on the recording material by heat and pressure.
It is hoped that the fixing device will shorten the waiting time (warm-up time) by instantly heating the heating member from the viewpoint of energy saving and keeping the user from waiting when using the image forming device. It is rare. As a fixing device that realizes energy saving and shortening of waiting time, a technique of directly heating a thin belt and a film or a thin-walled roller by a halogen heater has been proposed.

There is also known a fixing device that saves more energy and shortens the waiting time by using an endless fixing belt with a lower heat capacity than the heating roller and providing a pressure pad and its reinforcing member inside the fixing belt. .. Further, as the image forming apparatus is miniaturized, the diameter of the fixing belt is reduced, and the distance between the reinforcing member or the reflecting member inside the fixing belt and the heating element is shortened. When the distance between the reflecting member and the heating element is short, the amount of radiant heat reflected by the reflecting member passes through the heating element increases, and the heating efficiency for the fixing belt decreases.

If the thickness of the reflective member is reduced in order to secure the required distance between the heating element and the reflective member, the rigidity is reduced as a result of the reduction, and the reflective member may bend due to its own weight in the longitudinal direction. As a configuration for preventing the occurrence of such bending, a configuration in which the reflective member is completely fixed or integrally formed with the reinforcing member can be considered.

Further, by arranging the reinforcing member between the plurality of halogen heaters existing inside the fixing belt, it is possible to prevent the halogen heaters from heating each other. Further, the position of the reflective surface of the reflective member attached to the reinforcing member facing the halogen heater, that is, the position where the perpendicular line drawn from the center of the halogen heater to the reflective surface intersects the reflective surface is formed into a chevron shape. As a result, it is possible to eliminate the substantially vertical incident from the halogen heater to the reflective member, prevent the radiant heat from being reflected by the reflective member and heat the halogen heater itself, and heat the fixing belt with the reflected radiant heat.
In such a fixing device, by accurately matching the position where the vertical line intersects the reflecting surface with the position of the apex of the chevron shape, substantially vertical incident on the reflecting member is eliminated, and radiant heat heats the halogen heater itself. It is important to prevent it from happening.

In the configuration provided with the endless fixing belt having a low heat capacity and the pressure pad and the reinforcing member inside the fixing belt as described above, the pressure roller existing on the outside of the fixing belt and the pressure pad are brought into pressure contact with each other. Form a anchoring nip. At this time, a pressing force is applied to the entire longitudinal direction of the pressure pad and the reinforcing member, and the pressure pad and the reinforcing member are bent in the longitudinal direction. In the configuration in which the reflective member is attached to the reinforcing member, the reflective member follows the bending of the reinforcing member due to the pressing force, the apex of the reflective member chevron shape and the center of the halogen heater are displaced, and the heating efficiency of the fixing belt is improved. Will not be obtained.

It is conceivable to prevent this bending by increasing the size of the reinforcing member to increase the rigidity. However, since the reinforcing member needs to be housed inside the fixing belt, it is difficult to increase the size. Therefore, it is common to allow some bending and determine the shape of the pressure pad and the reinforcing member in consideration of the bending.

FIG. 8 is a perspective view of a fixing device 9 of a comparative example in which the reflector 40 is fixed to the stay member 61 by a flat head screw 42 and a stepped screw 43. FIG. 8 shows a state in which the fixing belt 38 is removed, and for convenience, only the trajectory of the fixing belt 38 is shown by a broken line.
FIG. 9A is a cross-sectional view of a portion where the reflector 40 is fixed by the flat head screw 42, and FIG. 9B is a schematic cross-sectional view of the portion where the reflector 40 is fixed by the stepped screw 43.
FIG. 10 is a schematic top view schematically showing a fixing device 9 of a comparative example viewed from above. FIG. 10 (a) shows the non-pressure contact state in which the pressure roller 30 is not urged toward the fixing belt 38, and FIG. 10 (b) shows the pressure roller 30 being urged toward the fixing belt 38. Indicates the time of pressure welding.
FIG. 11 is an explanatory diagram of the movement of the reflector 40 at the time of pressure contact of the pressurizing roller of the fixing device 9 of the comparative example.

A comparative example is a configuration in which the reflector 40 is supported by the stay member 61. As shown in FIG. 8, one end of the reflector 40 in the longitudinal direction is fixed to the stay member 61 by a flat screw 42 and the other end by a stepped screw 43. There is. Then, as shown in FIG. 10A, when the pressurizing roller is not pressure-welded, the position of the apex 41 of the chevron shape 46 of the reflector 40 and the position of the apex 41 in the lateral direction of the device (the direction parallel to the X axis in the drawing). The position of the center of the first halogen heater 50a coincides with that of the center.

As shown in FIG. 9A, the flat head screw 42 is fixed to the stay member 61 so as to sandwich one end of the reflector 40 between the stay member 61 and the back surface of the head 42a of the flat screw 42. .. Further, the tightening force of the flat head screw 42 generates a static frictional force between the reflector 40 and the stay member 61 to prevent the reflector 40 from moving in all directions with respect to the stay member 61.
On the other hand, as shown in FIG. 9B, the stepped screw 43 for fixing the other end of the reflector 40 has a gap A between the front surface of the reflector 40 and the back surface of the head 43a of the stepped screw 43. It is fixed to the stay member 61.

Further, the stepped screw 43 has a screw portion 43b screwed into the side surface of the stay member 61, a cylindrical first non-screw portion, and a cylindrical second non-screw portion.
The first non-threaded portion is a non-threaded portion 43c having a diameter larger than the diameter of the threaded portion 43b, extending from one end surface of the threaded portion 43b and extending in a direction away from the side surface of the stay member 61. .. The diameter of the second non-threaded portion is larger than the diameter of the non-threaded portion 43c, extends from the end surface opposite to the end surface connected to the threaded portion 43b of the non-threaded portion 43c, and is oriented away from the side surface of the stay member 61. The extending head 43a.

Further, the reflector 40 is provided with an elongated hole whose width direction is the longitudinal direction, and a stepped screw 43 is inserted into this elongated hole. The non-threaded portion 43c is arranged inside this elongated hole. Further, the diameter of the non-threaded portion 43c is smaller than the diameter of the slotted hole, and the length of the non-threaded portion 43c is larger than the thickness of the reflector 40. Further, the diameter of the head 43a is larger than the diameter of the slotted hole.

By attaching one end of the reflector 40 to the stay member 61 using the stepped screw 43 in this way, no tightening force is generated on the reflector 40, and when the reflector 40 is thermally expanded, the expansion direction is set to the longitudinal direction. It can be guided to the stepped screw side.

As shown in FIG. 10B, at the time of pressure welding of the pressure roller 30, the pressure roller 30 is urged toward the fixing belt 38 and pressurizes the stay member 61 via the fixing belt 38 and the pressure pad 60. Works. Then, when a pressing force acts on the stay member 61, the stay member 61 is bent so that the central portion in the longitudinal direction is separated from the pressurizing roller 30 with both ends in the longitudinal direction supported by the support side plate 70 as fulcrums. Deformation occurs.
At this time, the reflector 40 supported by the stay member 61 is deformed in the same manner as the stay member 61, following the deformation of the stay member 61. Specifically, static friction is generated between the screw-fastened vicinity of the reflector 40 and the stay member 61, and the static friction causes deformation of the reflector 40 that follows the deformation of the reinforcing member. The deformation at this time is a deformation that rotates toward the inside of the fixing belt around the screw-fastened portion of the reflective member.

When the reflector 40 is deformed in this way, as shown in FIG. 11, the bent portion 40a of the reflecting surface 40f bent at a predetermined angle with respect to the acting direction of the pressing force of the pressurizing roller 30 is deformed. Along with this, it moves as follows. That is, as shown by the dotted line 40a'in the figure, the reflector 40 moves closer to the first halogen heater 50a than before the deformation. When the distance between the reflector 40 and the first halogen heater 50a is short, the amount of the heater irradiation light reflected from the bent portion 40a of the reflector 40 passes through the first halogen heater 50a itself increases, so that the belt heating efficiency becomes higher. It goes down.

Further, due to the deformation of the reflector 40, the apex 41 of the mountain-shaped shape 46 described above is displaced so that the central portion in the longitudinal direction is separated from the pressure roller 30. Therefore, in the lateral direction of the device, the position of the apex 41 of the chevron shape 46 of the reflector 40 and the position of the center of the first halogen heater 50a are significantly deviated from each other. As a result, the incident radiant heat cannot be reflected to the fixing belt 38 while avoiding the passage of the first halogen heater 50a, and the belt heating efficiency is lowered.
In the above description of the comparative example, the first halogen heater 50a has been described, but the same problem also occurs with the second halogen heater 50b located on the opposite side of the stay member 61.

FIG. 4 is a perspective explanatory view of the fixing device 9 of the present embodiment.
As shown in FIG. 4, in the fixing device of the present embodiment, both ends of the reflector 40 in the longitudinal direction are supported by the stay member 61 via stepped screws 43, which are mounting members, respectively. Since the configuration of the stepped screw 43 is the same as that of the stepped screw 43 used in the fixing device of the comparative example described with reference to FIG. 9B, the description thereof will be omitted.

5A and 5B are schematic top views of the identification and attachment device, in which FIG. 5A shows the non-pressure welding and FIG. 5B shows the pressure welding.
As shown in FIG. 5A, when the pressure roller is not pressure-welded, the position of the apex 41 of the chevron shape 46 of the reflector 40 and the first position in the lateral direction of the device (direction parallel to the X axis in the figure). The position of the center of the halogen heater 50a coincides with that of the center.
As shown in FIG. 5B, a pressing force acts on the stay member 61 at the time of pressure welding of the pressure roller 30. Then, as in the comparative example, the stay member 61 is deformed so that the central portion in the longitudinal direction is separated from the pressure roller 30 with both ends in the longitudinal direction supported by the support side plate 70 as fulcrums. Occurs.

In the fixing device 9 of the present embodiment, both ends of the reflector 40 in the longitudinal direction are attached to the stay member 61 by stepped screws 43. As a result, the static frictional force between the stay member 61 and the reflector 40 generated by the tightening force of the screw can be remarkably lowered as compared with the fixing device of the comparative example, and the reflector 40 follows the deformation of the stay member 61. It can be prevented from deforming. As a result, the distance between the first halogen heater 50a and the bent portion 40a of the reflector 40 does not change, and the position of the center of the first halogen heater 50a and the apex 41 of the chevron portion of the reflector 40 does not shift. Therefore, the belt heating efficiency can be maintained. As a result, it is possible to eliminate the incident of radiant heat substantially perpendicular to the reflector 40, to avoid passing through the first halogen heater 50a and to maintain a state in which the radiant heat incident on the reflector 40 can be reflected to the fixing belt 38, and to maintain the belt heating efficiency. be able to.
Further, by maintaining the belt heating efficiency in the fixing device 9, the power consumption of the entire copying machine 500 can be reduced, and energy saving can be achieved.

6 and 7 show the fixing device 9 having a shape other than the chevron shape 46 as a shape that reflects the radiant heat in a direction different from the direction in which the radiant heat is incident on the reflecting surface 40f of the reflector 40. It is a schematic block diagram.
Since they are common except that the shape of the portion of the reflector 40 facing the halogen heater 50 is different, only the differences will be described.

The fixing device 9 shown in FIG. 6 includes an arc shape 44 that projects toward the halogen heater 50 at a portion of the reflector 40 that faces the halogen heater 50. On the outer peripheral surface of such an arc shape 44, the portion perpendicular to the incident direction of the radiant heat is in a very limited range, and the radiant heat incident in the other range is reflected in a direction different from the incident direction. .. Therefore, similarly to the fixing device 9 of the above-described embodiment, the radiant heat incident on the reflecting surface 40f can be reflected toward the fixing belt 38 while avoiding the passage of the halogen heater 50.

The fixing device 9 shown in FIG. 7 is provided with a valley-shaped shape 45 recessed with respect to the halogen heater 50 at a portion of the reflector 40 facing the halogen heater 50. Since the slope forming such a valley shape 45 and the incident direction of the radiant heat are not perpendicular to each other, the radiant heat is reflected in a direction different from the incident direction. Therefore, similarly to the fixing device 9 of the above-described embodiment, the radiant heat incident on the reflecting surface 40f can be reflected toward the fixing belt 38 while avoiding the passage of the halogen heater 50. In the case of the configuration including the valley shape 45 shown in FIG. 7, if the two slopes of the valley shape 45 are at right angles to each other, radiant heat may be reflected in the incident direction, so that the two slopes are formed. It is desirable to arrange them so that they are not at right angles.

FIG. 19 shows that the reflecting surface 40f of the reflector 40 has a shape that reflects radiant heat in a direction different from the direction in which the radiant heat is incident, and connects two parallel and stepped flat surfaces and the two flat surfaces. It is a schematic block diagram of the fixing device 9 which has an inclined plane part.
Since the reflector 40 is common to the fixing device 9 shown in FIG. 2 except that the shape of the reflector 40 is different, only the differences will be described.

In the fixing device 9 shown in FIG. 19, two reflectors 40 are arranged so as to cover the standing portion of the stay member 61 that stands up and supports the pressure pad 60. As shown in FIG. 19, the relevant portion of the reflector 40 is a first reflection plane portion 46A and a third reflection plane portion 46C, which are two parallel and staggered plane portions, and a first reflection plane portion 46A and a third reflection plane. It is formed by a second reflection plane portion 46B, which is an inclined plane portion connecting the portions 46C.

The two halogen heaters 50 (50a, 50b) are located at locations facing the second reflection plane portion 46B, respectively, and the angle of incidence of the radiant heat incident on the second reflection plane portion 46B is not perpendicular to the slope. .. Therefore, the second reflection plane portion 46B reflects the radiant heat in a direction different from the direction in which the radiant heat is incident, and the radiant heat reflected by the second reflection plane portion 46B can be suppressed from going toward the halogen heater 50. Therefore, as shown by the arrow “H” in FIG. 10, the radiant heat from the halogen heater 50 incident on the second reflection plane portion 46B does not return to the halogen heater 50 and is fixed on the side opposite to the pressure pad 60. It is reflected toward the belt 38. Therefore, by preventing the radiant heat from heating the halogen heater 50 itself (the glass tube or the like constituting the halogen heater 50), the fixing belt 38 can be efficiently heated.

Next, a modified example of fixing the reflector 40 to the stay member 61 will be described.
FIG. 20 (a) is a schematic configuration diagram showing the vicinity of the reflector fixing portion on one end side in the longitudinal direction in the modified example, and FIG. 20 (b) is a schematic configuration diagram showing the vicinity of the reflector fixing portion on the other end side in the longitudinal direction in the modified example. It is a block diagram. 21 (a) is a schematic cross-sectional view showing the vicinity of the reflector fixing portion on one end side in the longitudinal direction in the modified example, and FIG. 21 (b) is a view seen from the C1 direction of FIG. 21 (a). 21 (c) is a view seen from the C2 direction of FIG. 21 (a). In this modification, the reflector 40 having the shape shown in FIG. 19 is used.

In this modification, as shown in FIG. 21A, the stay member 61 is provided with a recess 61f into which the non-threaded portion 43c of the stepped screw 43 enters. The thickness of the non-threaded portion 43c (length in the Z direction in the drawing) is thicker than the sum of the depth of the recess 61f and the thickness of the reflector 40. As a result, even in the modified example, as shown in FIG. 21A, a predetermined gap A is formed between the head 43a of the stepped screw 43 and the reflector 40.

As described above, also in the first modification, the mounting member for attaching the reflector 40 to the stay member 61 is a stepped screw 43, and a gap is formed between the head 43a of the stepped screw 43 and the reflector 40. Therefore, the reflector 40 can be prevented from deforming following the deformation of the stay member 61. Therefore, it is possible to suppress a part of the radiant heat reflected by the reflector 40 toward the halogen heater 50, and it is possible to maintain the belt heating efficiency.

The gap A is 0.5 mm or less, preferably 0.2 to 0.3 mm. If it exceeds 0.5 mm, the backlash of the reflector 40 in the Z-axis direction becomes large, and the reflector 40 may be tilted with respect to the surface of the stay member 61 facing the reflector 40. If the reflector 40 is tilted, the radiant heat of the halogen heater 50 cannot be uniformly reflected in the width direction (Y direction) of the fixing belt, and there is a possibility that temperature unevenness in the width direction of the fixing belt may occur. By setting the gap A to 0.5 mm or less, it is possible to prevent the reflector 40 from tilting with respect to the surface of the stay member 61 facing the reflector 40, and suppress temperature unevenness in the width direction of the fixing belt 38. can do.

Further, as shown in FIG. 20, mounting portions 40b1 and 40b2 that are attached to the stay member 61 by the stepped screws 43 are provided at both ends of the reflector 40 in the longitudinal direction. One mounting portion 40b1 is provided with a circular hole 40d having a diameter substantially the same as the diameter of the non-threaded portion 43c through which the stepped screw 43 penetrates, and the other mounting portion 40b2 extends in the longitudinal direction. An elongated hole 40c is provided.

The stepped screw 43 penetrates the round hole 40d and is screwed to the first screw hole 61e of the stay member 61, so that the reflector 40 is referred to as the X direction (hereinafter referred to as the lateral direction) in the drawing with respect to the stay member 61. It may be positioned in the Y direction (longitudinal direction) in the figure. Further, the minor axis of the elongated hole 40c extending in the longitudinal direction is substantially the same as the diameter of the non-threaded portion 43c of the stepped screw 43. Therefore, the stepped screw 43 penetrates the elongated hole 40c and is screwed into the second screw hole 61d of the stay member 61, so that the reflector 40 is positioned with respect to the stay member 61 in the Z-axis direction in the drawing. NS. Further, a part of the head portion 43a of each stepped screw 43 penetrating the holes 40c and 40d faces the reflector 40, so that the reflector 40 is positioned and fixed to the stay member 61 in the Z-axis direction in the drawing.

Also in this modification, one of the holes through which the stepped screws 43 provided at both ends in the longitudinal direction of the reflector penetrates is an elongated hole 40c extending in the longitudinal direction. Therefore, when the temperature of the reflector 40 rises due to the radiant heat of the halogen heater 50 and the heat expands, the elongated hole 40c slides toward the end side in the longitudinal direction with respect to the stepped screw 43, and the heat expansion of the reflector 40 occurs. You can escape. As a result, it is possible to prevent the reflector 40 from bending due to thermal expansion so that the central portion of the reflector 40 in the longitudinal direction is separated from the surface of the stay member 61 facing the reflector 40.

Further, in this modification, the reflector 40 is attached to the stay member 61 in the lateral direction (X direction) at only one place. As a result, the reflector 40 is bent by the thermal expansion so that the central portion of the reflector 40 in the longitudinal direction is separated from the surface of the stay member 61 facing the reflector 40 without hindering the thermal expansion of the reflector 40 in the lateral direction. It is possible to prevent such a situation from occurring.

Further, by making the other side of the hole through which the stepped screw 43 penetrates a round hole 40d having a diameter substantially the same as the diameter of the non-threaded portion 43c of the stepped screw 43, the reflector 40 can be made in the longitudinal direction (Y direction) and the short side. It can be attached to the stay member 61 with high accuracy in the direction (X direction).

Further, in this modification, the stepped screw 43 for attaching the reflector 40 to the first surface which is the upper surface (the surface on the downstream side in the paper transport direction) of the stay member 61 and the lower surface of the stay member 61 (the surface on the upstream side in the paper transport direction). The fixed position of the stepped screw 43 for attaching the reflector 40 to the first surface and the stepped screw 43 for attaching the reflector 40 to the second surface so that the stepped screw 43 for attaching the reflector 40 to the second surface does not interfere with each other. The fixing position of the screw 43 is different from that in the longitudinal direction (Y direction). Specifically, the fixing position of the stepped screw 43 penetrating the elongated hole 40c is provided on the central side in the longitudinal direction with respect to the fixing position of the stepped screw 43 penetrating the round hole 40d.

Further, on the side of the mounting portion 40b1 having the round hole 40d of the reflector 40, there is a notch-shaped relief portion 40h for allowing the screw portion 43b of the stepped screw 43 penetrating the elongated hole 40c to escape. Further, the stepped screw 43 penetrating the round hole 40d of the reflector 40 is screwed into the first screw hole 61e of the stay member 61, and the stepped screw 43 penetrating the elongated hole 40c is larger than the first screw hole 61e. It is screwed into the second screw hole 61d provided on the center side in the longitudinal direction.

Further, in this modification, as shown in FIGS. 20A and 20B, the reflector 40 attached to the first surface of the stay member 61 has an attachment portion 40b1 having a round hole 40d on one end side in the longitudinal direction. It is attached to the stay member 61 so that the attachment portion 40b2, which is located and has an elongated hole 40c on the other end side in the longitudinal direction, is located. On the other hand, in the reflector 40 attached to the second surface of the stay member 61, the attachment portion 40b2 having the elongated hole 40c on one end side in the longitudinal direction is located, and the attachment portion 40b1 having the round hole 40d on the other end side in the longitudinal direction is located. It is attached to the stay member 61. With this configuration, the reflector 40 mounted on the first surface and the reflector 40 mounted on the second surface can be shared, and the cost of the device can be reduced.

Further, as shown in FIG. 20, in this modified example, the mounting portions 40b1 and 40b2 are provided on the side away from the pressure pad 60 (upper side in the drawing), but are provided on the pressure pad side. The reflector 40 may be attached to the stay member 61 on the pressure pad side.

FIG. 22 is a diagram illustrating a position where the reflector 40 is attached to the stay member 61. Note that FIG. 22 omits the heat generation region 501 of the first halogen heater 50a.
As shown in FIG. 22, in this modification, the position where the reflector 40 is attached to the stay member 61 is the heat generation region on the most end side (outside) of the first and second halogen heaters 50a and 50b in the longitudinal direction. It is provided in the end region B on the end side of 501 and on the center side (inside) of the support side plate 70. By providing the reflector 40 to the stay member 61 on the end side of the heat generating region 501 on the farthest end side in the longitudinal direction, radiant heat from the halogen heater is suppressed from being incident on the stepped screw 43. be able to. As a result, it is possible to suppress a decrease in the reflection efficiency of radiant heat.

Further, when the mounting position of the reflector 40 to the stay member 61 is provided outside the support side plate 70, the fitting portion 61a of the stay member 61 (with the reflector 40 attached to the stay member 61 by the stepped screw 43) When the (see FIG. 14) is passed through the fitting hole 70b (see FIG. 14) of the support side plate 70, the head 43a of the stepped screw 43 may be caught in the fitting hole 70b. As a result, the fitting portion 61a cannot be smoothly penetrated into the fitting hole 70b, and the assembling property is poor. Further, when the reflector 40 is attached to the stay member 61 after the fitting portion 61a is passed through the fitting hole 70b, the reflector 40 is inserted into the fitting hole 70b through which the stay member 61 penetrates and the gap is narrowed. It is necessary to penetrate the reflector 40, and the reflector 40 cannot be easily penetrated into the fitting hole 70b through which the fitting portion 61a has penetrated, and the assembling property is also poor.

Further, when the mounting position of the reflector 40 to the stay member 61 is provided on the end side of the support side plate 70, the length of the reflector 40 in the longitudinal direction needs to be longer than the distance between the pair of support side plates 70. There is a problem that the material cost increases.

On the other hand, as in this modification, the reflector 40 is attached to the stay member 61 at the center side of the support side plate 70, so that the reflector 40 is attached to the stay member 61 with the stepped screw 43. When the fitting portion 61a of the member 61 is passed through the fitting hole 70b of the support side plate 70, the head 43a of the stepped screw 43 does not get caught in the fitting hole 70b. Therefore, the fitting portion 61a can be smoothly passed through the fitting hole 70b, and the assembly can be easily performed. Further, when the reflector 40 is attached to the stay member 61 after the fitting portion 61a is passed through the fitting hole 70b, the reflector 40 is inserted into the fitting hole 70b through which the fitting portion 61a is penetrated and the gap is narrowed. It is not necessary to penetrate it, and it can be easily assembled. Further, the length of the reflector 40 in the longitudinal direction can be made shorter than the distance between the pair of support side plates 70, and there is an advantage that the material cost can be suppressed.

Further, as shown in FIG. 22, one of the reflector mounting positions at both ends in the longitudinal direction is provided in the region B1 on the end side of the center position of the end region B. A mounting portion 40b1 having a round hole 40d is located in the region B1 on the end side. In this way, by providing the reflector 40 in the region B1 on the end side from the central position of the end region B, the reflector 40 can be attached to the stay member 61 at a position close to the support side plate 70. In this modification, the mounting portion 40b1 having the round hole 40d, which is the main reference for positioning and fixing, is mounted on the stay member 61 in the region B1 on the end side.

As described above, the pressure of the pressure roller 30 causes the stay member 61 to bend and deform with the portion supported by the support side plate 70 as a fulcrum. By attaching the reflector 40 to the stay member 61 at a position close to the support side plate 70, the reflector 40 can be attached in the vicinity of the portion supported by the support side plate 70 of the stay member 61. As a result, the stay member 61 suppresses fluctuations in the mounting position in the lateral direction (X direction) when bending deformation occurs, with the portion supported by the support side plate 70 as a fulcrum due to the pressing force of the pressure roller 30. be able to. As a result, it is possible to suppress the displacement of the reflector 40 in the lateral direction (X direction) when the stay member 61 is bent, and it is possible to suppress the decrease in the reflection efficiency. Further, in this modification, one of the reflector mounting positions at both ends in the longitudinal direction is provided in the region B1 on the end side, but by providing both in the region B1 on the end side of the end region B, the stay member It is preferable that the position shift of the reflector 40 in the lateral direction (X direction) when the 61 is bent can be further suppressed.

FIG. 23 is a diagram showing an example in which the reflector 40 is attached to the stay member 61 at two locations in the lateral direction. FIG. 23 (a) is a schematic configuration diagram of the reflector 40, and FIG. 23 (b) is a schematic configuration diagram showing a state in which the reflector 40 is attached to the stay member 61. In FIG. 23, the reflector 40 has an arc shape 44 protruding toward the halogen heater 50 at a portion facing the halogen heater 50 shown in FIG. 6 above.

As shown in FIG. 23 (a), the reflector 40 is located on one end side (longitudinal direction) of a flat surface portion on the side opposite to the pressure pad side (upper side in the drawing) that abuts on the side surface of the stay member 61 with the arc shape 44 interposed therebetween. A round hole 40d is provided on the right side in the drawing, and an elongated hole 40c extending in the longitudinal direction is provided on the other end side (left side in the drawing). Further, an elongated hole 40e extending in the lateral direction (upper and lower direction in the drawing) on one end side in the longitudinal direction of the flat surface portion that abuts on the side surface of the stay member 61 on the pressure pad side (lower side in the drawing) with the arc shape 44 interposed therebetween. And has a square hole 40 g on the other end side in the longitudinal direction.

As shown in FIG. 23B, the non-threaded portion 43c of the stepped screw 43 penetrates through the holes 40c, 40d, 40e, 40g, and the reflector 40 is attached to the stay member 61 by the stepped screw 43. The hole diameter of the round hole 40d is substantially the same as the diameter of the non-threaded portion 43c of the stepped screw 43, and the stepped screw 43 penetrates the round hole 40d and is screwed to the stay member 61. The reflector 40 is positioned with respect to the stay member 61 in the X direction (short direction) and the longitudinal direction (Y direction in the drawing) in the drawing.

The minor axis of the elongated hole 40c extending in the longitudinal direction and the minor axis of the elongated hole 40e extending in the lateral direction are substantially the same as the diameter of the non-threaded portion 43c of the stepped screw 43. Therefore, the stepped screw 43 penetrates the elongated holes 40c and 40e and is screwed to the stay member 61, so that the reflector 40 is positioned with respect to the stay member 61 in the Z-axis direction in the drawing.

Further, a part of the head 43a of each stepped screw penetrating the holes 40c, 40d, 40e, 40g faces the reflector 40, so that the reflector 40 is positioned and fixed in the Z-axis direction in the drawing with respect to the stay member 61. Will be done.

In the configuration shown in FIG. 23, when the reflector 40 is thermally expanded in the longitudinal direction, the elongated hole 40c and the square hole 40g extending in the longitudinal direction on the other end side in the longitudinal direction (left side in the drawing) are provided with respect to the stepped screw 43. By moving relatively to the left side in the figure, thermal expansion can be released in the longitudinal direction. Therefore, it is possible to prevent the reflector 40 from bending in the longitudinal direction due to thermal expansion.

On the other hand, when the reflector 40 is thermally expanded in the lateral direction, the elongated hole 40e and the square hole 40g extending in the lateral direction on one end side in the longitudinal direction (left side in the drawing) are shown relative to the stepped screw 43 in the drawing. By moving downward, thermal expansion can be released in the lateral direction. Therefore, it is possible to prevent the reflector 40 from bending in the lateral direction due to thermal expansion.

The copying machine 500 of the present embodiment is a vertical transport type image forming apparatus that transports paper from below to above. Therefore, the fixing device 9 has a structure in which the fixing belt 38 and the pressure roller 30 are arranged in the horizontal direction. The image forming apparatus may be a horizontal conveying type that conveys paper in the horizontal direction. In this case, as the fixing device, a fixing belt and a pressure roller are arranged in the vertical direction, and the fixing device of the above-described embodiment is used. A configuration in which 9 is rotated by 90 [°] can be used.

The above description is an example, and the effect peculiar to each of the following aspects is exhibited.

(Aspect A)
A rotating body such as a fixing belt 38, a contact member such as a pressure roller 30 that comes into contact with the outer peripheral surface of the rotating body, and a nip such as a fixing nip SN that is arranged inside the rotating body and comes into contact with the contact member via the rotating body. A nip forming member such as a pressure pad 60 forming a portion, a stay such as a stay member 61 supporting the nip forming member, a heating element such as a halogen heater 50 arranged inside the rotating body, and a rotating body of the stay. The reflecting member is provided with a holding means such as a support side plate 70 that holds both ends in the width direction orthogonal to the surface moving direction of the above, and a reflecting member such as a reflector 40 that reflects the radiant heat radiated from the heating element on the reflecting surface. In the fixing device 9 in which both ends in the width direction are attached to the stay by an attachment member such as a stepped screw 43, the attachment position of the reflection member to the stay is set to the heat generating portion of the heating element such as the light emitting portion filament in the width direction. It was arranged on the outside of the end and on the center side of the holding means.
When the mounting position of the reflective member to the stay is outside the holding means in the width direction as in the configuration described in Patent Document 1, the widthwise end of the stay is held in a state where the reflective member is mounted on the stay by the mounting member. When penetrating through the holding means, the mounting member may get caught in the hole through which the stay of the holding means penetrates. As a result, the stay cannot be smoothly penetrated through the holding means, and the assembling property is poor. Further, when the reflective member is attached to the stay after the stay is penetrated through the holding means, it is necessary to penetrate the reflective member through the hole of the holding means through which the stay penetrates and the gap is narrowed. It cannot be easily penetrated into the hole through which the stay has penetrated, and the assembling property is also poor.
Therefore, in the first aspect, the mounting position of the reflective member on the stay is provided on the central side of the holding means in the width direction. By providing the mounting position on the center side of the holding means, the mounting member stays on the holding means when the widthwise end of the stay is passed through the holding means while the reflective member is mounted on the stay by the mounting member. Will not get caught in the hole through which. Therefore, the stay can be smoothly penetrated through the holding means, and the stay can be easily assembled. Further, when the reflective member is attached to the stay after the stay is penetrated through the holding means, it is not necessary to penetrate the reflective member through the hole of the holding means through which the stay penetrates and the gap is narrowed, and the reflex member can be easily assembled. It can be performed.
Further, even when the reflection member is attached to the stay at the center side of the holding means, the reflection member is attached to the stay at the end of the heating element of the heating element in the width direction. If it is provided on the center side, a part of the radiant heat will be applied to the mounting member. The reflectance of radiant heat of such a mounting member is worse than that of the reflective surface of the reflective member. Therefore, another problem arises that the heating efficiency of the rotating body is lowered.
Therefore, in the first aspect, the mounting position of the reflective member on the stay is arranged on the outer side of the end portion of the heating portion of the heating element and on the central side of the holding means in the width direction. Thereby, the assembling property of the stay to the holding means can be improved. Further, the radiant heat radiated to the mounting member can be reduced as compared with the case where the reflective member is mounted on the stay in the width direction from the end of the heating element of the heating element and is provided on the center side. As a result, it is possible to suppress a decrease in the heating efficiency of the rotating body as compared with the position where the reflective member is attached to the stay in the width direction of the heating element with respect to the end portion of the heating element on the central side.

(Aspect B)
In aspect A, the mounting position of the reflective member such as the reflector 40 to the stay such as the stay member 61 is set in the width direction from the end of the heating element of the heating element such as the light emitting portion filament such as the halogen heater 50 to the support side plate 70 or the like. It was arranged closer to the holding means than the center of the area between the holding means and the holding means.
According to this, as described in the embodiment, the mounting position of the reflective member on the stay is close to the position where the reflective member is held by the holding means such as the support side plate 70 of the stay. The deformation of the stay due to the contact pressure of the contact member such as the pressure roller 30 is deformed with the portion held by the stay holding means as a fulcrum. Therefore, by setting the mounting position of the reflective member on the stay close to the position where the stay is held by the holding means, it is possible to suppress the movement of the mounting position when the stay is deformed. As a result, the movement of the reflective member due to the movement of the mounting position can be suppressed, and the action of efficiently heating the rotating body can be maintained by the shape of the reflective surface of the reflective member.

(Aspect C)
In aspects A or B, the angle of the position of the reflective member such as the reflector 40 facing the heating element such as a halogen heater on the reflective surface is changed.
According to this, as described in the embodiment, it is possible to prevent the radiant heat of the heating element reflected by the reflecting surface from going toward the heating element.

(Aspect D)
A rotating body such as an endless fixing belt provided rotatably, a contact member such as a pressure roller that comes into contact with the outer peripheral surface of the rotating body, and the rotating body arranged inside the rotating body and via the rotating body. A nip forming member such as a pressure pad that comes into contact with a contact member to form a nip portion such as a fixing nip SN, a stay such as a stay member 61 that supports the nip forming member, and a halogen arranged inside the rotating body. In a fixing device including a heating element such as a heater 50 and a reflecting member such as a reflector 40 that is supported by the stay and reflects radiant heat radiated from the heating element on a reflecting surface such as a reflecting surface 40f.
Mounting members such as stepped screws 43 for mounting the reflective member directly or indirectly to the stay are provided at both ends in the width direction of the reflective member, and at least a part of the reflective surface is in contact with the nip forming member. It has a bent portion 40a having an angle with respect to the contact direction with the member, an arc shape 44, a valley shape 45, a mountain shape 46, and the like.
The deformation of the stay in the rotation direction around the mounting member in the surface direction of the reflecting surface caused by the contact pressure with the contact member is not transmitted to the reflecting member by the mounting structure using the mounting member. It is characterized by having done it.

Conventionally, a rotating cylindrical rotating body, a contact member that contacts the outer peripheral surface of the rotating body, and a nip forming member that is arranged inside the rotating body and contacts the contact member via the rotating body to form a nip portion. A fixing device equipped with and is known. A reflective member that reflects radiant heat radiated from the heating element on the reflective surface is attached to the stay that supports the nip forming member.

Patent Document 1 describes such a fixing device including a fixing member which is a nip forming member and a reinforcing member which is a stay for reinforcing the strength of the fixing member. The reinforcing member is arranged so that the end portion in the width direction (direction orthogonal to the paper passing direction) is fixedly supported by the side plate of the fixing device and the internal space of the fixing belt, which is a rotating body, is separated into two. Further, one end surface of the reinforcing member in the longitudinal direction is in contact with the fixing member, and is in contact with the pressure roller as the contact member via the fixing member and the fixing belt. Furthermore, a reflective member is fixedly provided on the surface of the reinforcing member facing the heater, which is a heating element.

As a shape for improving the heating efficiency of the fixing belt, the reflective surface of the reflective member is formed with a curved surface shape such that the central portion of the reflective surface facing the heater approaches the heater when viewed in a cross section orthogonal to the width direction. ing. By diffusing and reflecting the heat (light) from the heater to the inner peripheral surface of the fixing member by this curved surface shape, the heater light is uniformly irradiated in a wide range as compared with the case where the reflecting surface of the reflecting member is flat. It is said that the heating efficiency of the fixing belt can be improved.
Further, the reflective member is attached to the reinforcing member by a screw at one end in the width direction and a step screw at the other end. The mounting portion of the step screw of the reflective member is provided with an elongated hole whose width direction is the longitudinal direction, and when the reflective member receives the heat of the heater and thermally expands, the step portion of the step screw is inside the elongated hole. By sliding relatively, it is possible to prevent warping of the reflective member in the width direction.

However, the fixing device described in Patent Document 1 may reduce the effect of improving the heating efficiency of the fixing belt due to the shape of the reflective surface.

In the fixing device described in Patent Document 1, one end of the reflective member in the width direction is fixed to the reinforcing member by a screw. For this reason, when the reinforcing member that comes into contact with the pressurizing roller via the fixing member and the fixing belt bends toward the inside of the fixing belt due to the contact pressure of the pressurizing roller, the vicinity of the reflective member screwed together. Static friction occurs with the reinforcing member. Due to this static friction, the reflective member is deformed following the deformation of the reinforcing member. Specifically, a deformation occurs in which the reflective member rotates inward of the fixing belt around the screwed portion. Due to the deformation of the reflective member, the curved surface shape of the reflective surface and the position of the heating element may deviate from each other, and the efficiency of improving the heating efficiency of the fixing belt due to the curved surface shape described above may be lowered.
The shape for improving the heating efficiency of the fixing belt is not limited to the curved surface shape described above, and the same problem occurs if at least a part of the reflecting surface has an angle with respect to the pressure direction of the pressure roller. Can occur.

In the present aspect D, as described in the above embodiment, the deformation in the rotation direction centering on the mounting member in the surface direction of the reflective surface, which occurs when the stay is deformed by the contact pressure of the contact member, is applied to the reflective member. Since it is not transmitted, the following can be done. That is, it is possible to prevent the reflective member from being deformed due to the deformation in the rotational direction about the mounting member in the surface direction of the reflective surface of the stay. As a result, even if the stay is bent toward the inside of the rotating body due to the contact pressure of the contact member, it is possible to realize a configuration in which the reflecting member is not deformed following the bending. As a result, it is possible to prevent the positional relationship between the slope shape of the reflective member and the heating element from shifting due to the bending of the stay, and to maintain the positional relationship. Therefore, even if the stay is bent, by maintaining the positional relationship between the slope shape of the reflective member and the heating element, it is possible to maintain the action of efficiently heating the rotating body by the shape of the reflective surface of the reflective member. ..

(Aspect E)
In the D aspect, the mounting member such as the stepped screw 43 restricts the movement of the stay such as the pressure pad 60 and the stay member 61 in the deformation direction by at least the contact pressure of the contact member such as the pressure roller.

(Aspect F)
In aspects C to E, the radiant heat radiated from the heating element is applied to a position where the reflecting member such as the reflector 40 faces the heating element such as the halogen heater 50 on the reflecting surface such as the reflecting surface 40f. It is characterized by having a bent portion 40a that reflects in a direction that does not face the heating element, an arc shape 44, a valley shape 45, a mountain shape 46, and the like.
According to this aspect, as described in the above embodiment, the radiant heat incident on the reflecting surface can be reflected toward the inner peripheral surface of the rotating body while avoiding the passage of the heating element, and the radiant heat can be reflected toward the inner peripheral surface of the rotating body itself. Can be prevented from heating.

(Aspect G)
In any one of the aspects A to F, the reflecting member such as the reflector 40 has holes at both ends in the width direction through which the mounting member such as the stepped screw 43 penetrates, and the holes at both ends in the width direction. One of them is an elongated hole extending in the width direction.
According to this, as described in the embodiment, when the reflective member of the reflector 40 thermally expands, the elongated hole moves relative to the mounting member such as the stepped screw 43 to release the thermal expansion. Can be done. As a result, it is possible to prevent the reflective member from bending and deforming due to thermal expansion.

(Aspect H)
In any one of the aspects A to G, in the direction of contact of the contact member such as the pressure roller 30 with the rotating body such as the fixing belt 38, the reflection member such as the reflector 40 is attached to the stay at only one place. bottom.
According to this, as described in the embodiment, the reflector 40 can be thermally expanded in the contact direction, and the deformation of the reflector 40 due to the thermal expansion can be suppressed.

(Aspect I)
In any one of aspects A to H, the mounting member such as the stepped screw 43 penetrates the reflective member with a diameter larger than that of the first part such as the screw portion 43b fixed to the stay and the first part. A second part such as a non-screwed part 43c that abuts on a surface of the stay that is orthogonal to the mounting direction of the mounting member, and a part having a diameter larger than that of the second part and facing the reflecting surface of the reflecting member. The thickness of the second part is set so that the third part has a third part such as the head portion 43a to be formed and the third part has a predetermined gap with respect to the reflective member.

According to this, a mounting structure using a mounting member is provided so that the deformation of the stay in the rotational direction around the mounting member in the surface direction of the reflective surface caused by the contact pressure with the contact member is not transmitted to the reflective member. It can be realized. This makes it possible to prevent the reflective member from being deformed due to deformation in the rotational direction around the mounting member in the surface direction of the reflective surface of the stay. Therefore, even if the stay is bent toward the inside of the rotating body due to the contact pressure of the contact member, the reflection member can be prevented from being deformed following the bending. As a result, it is possible to prevent the positional relationship between the slope shape of the reflective member and the heating element from shifting due to the bending of the stay, and to maintain the positional relationship. Therefore, even if the stay is bent, by maintaining the positional relationship between the slope shape of the reflective member and the heating element, it is possible to maintain the action of efficiently heating the rotating body by the shape of the reflective surface of the reflective member. ..

(Aspect J)
In any one of aspects A to I, the stay has a contact portion with which the nip forming member such as a pressure pad 60 abuts, and an upright portion that stands up from the contact portion toward the inside of the rotating body. The heating element is arranged so as to face the side surface of the upright portion, and the reflective member is supported on the side surface of the upright portion.

(Aspect K)
In aspect J, the mounting member such as the stepped screw 43 moves in parallel to the side surface of the upright portion in the longitudinal direction of the reflecting member such as the reflector 40, and moves vertically away from the side surface by a predetermined distance. Alternatively, the reflective member is attached to the side surface, allowing at least one of movements tilted at a predetermined angle with respect to the side surface.

(Aspect L)
In the aspect J or K, the reflective member such as the reflector 40 has two flat surfaces parallel to and staggered from the upright portion and an inclined flat surface portion connecting the two flat surfaces.
According to this, as shown in FIG. 19 above, it is possible to suppress the radiant heat reflected from the reflecting surface of the reflecting member from going toward the heating element such as the halogen heater 50.

(Aspect M)
In the aspect J or K, the reflective surface has a convex shape such as a chevron shape 46 or an arc shape 44 protruding from the reflective surface such as the reflective surface 40f toward the heating element such as the halogen heater 50. The reflective member was attached to the stay so that the reflective member was located between the heating element and the upright portion and the center point of the heating element was located on an extension line in the convex projection direction.
According to this, as described in the above embodiment, the radiant heat incident on the reflecting surface can be reflected toward the rotating body such as the fixing belt 38 while avoiding the passage of the heating element, and the radiant heat heats the heating element itself. Can be prevented.

(Aspect N)
In the M aspect, the convex shape is a mountain-shaped shape protruding from the reflective surface toward the heating element.
According to this, as described in the above embodiment, the radiant heat incident on the reflecting surface at the position facing the heating element is incident on the mountain-shaped slope and reflected in a direction different from the incident direction. This makes it possible to realize a configuration in which the reflected radiant heat is prevented from passing through the heating element and is incident on the rotating body such as the fixing belt 38.

(Aspect O)
In the M aspect, the convex shape is an arc shape protruding from the reflective surface toward the heating element.
According to this, as described in the above embodiment, the radiant heat incident on the reflection surface in the vicinity of the position facing the heating element is incident on the arc-shaped surface and reflected in a direction different from the incident direction. .. This makes it possible to realize a configuration in which the reflected radiant heat is prevented from passing through the heating element and is incident on the rotating body such as the fixing belt 38.

(Aspect P)
A copying machine 500 including a toner image forming means such as an image forming unit 200 for forming a toner image on a recording medium using toner, and a fixing means for fixing the toner image on a recording medium such as transfer paper S by heating. In the image forming apparatus such as the above, as the fixing means, a fixing device such as the fixing device 9 according to any one of the aspects A to O is used.
According to this, as described in the above-described embodiment, the energy saving of the entire image forming apparatus can be achieved by maintaining the belt heating efficiency in the fixing apparatus.

1 Image drawing device 2 Charging device 3 Photoconductor 5 Developer 6 Primary transfer roller 8 Paper ejection tray 9 Fixing device 10 Paper feed cassette 16 Intermediate transfer belt 20 Toner bottle 26 Secondary transfer roller 30 Pressurizing roller 38 Fixing belt 40 Reflector 40a Folded part 40f Reflective surface 41 Crest-shaped apex 42 Flat head screw 42a Flat head screw head 43 Stepped screw 43a Stepped screw head 44 Arc shape 45 Valley shape 46 Crest shape 50a First halogen heater 50b Second Halogen heater 60 Pressurizing pad 61 Stay member 70 Support side plate 70a Through hole 70b Fitting hole 72 Connecting plate 100 Writing unit 200 Image forming unit 500 Copier

Japanese Unexamined Patent Publication No. 2011-59365

Claims (15)

With a rotating body,
A contact member that comes into contact with the outer peripheral surface of the rotating body,
A nip forming member arranged inside the rotating body and contacting the contact member via the rotating body to form a nip portion.
A stay that supports the nip forming member and
A heating element arranged inside the rotating body and
Holding means for holding both ends of the stay in the width direction orthogonal to the surface moving direction of the rotating body, and
A reflecting member that reflects radiant heat radiated from the heating element on a reflecting surface is provided.
In the fixing device in which both ends of the reflective member in the width direction are attached to the stay by the attachment member.
A fixing device characterized in that the mounting position of the reflective member on the stay is arranged on the outer side of the end portion of the heat generating portion of the heating element and on the central side of the holding means in the width direction . The fixing device according to請Motomeko 1,
The reflection member is attached to the stay in the width direction so as to be closer to the holding means than the center of the region between the end of the heating element of the heating element and the holding means. Fixing device . In the fixing device according to claim 1 or 2,
At least a part of the reflective surface has a shape at an angle with respect to the contact direction between the nip forming member and the contact member.
The deformation of the stay in the rotation direction around the mounting member in the surface direction of the reflecting surface caused by the contact pressure with the contact member is not transmitted to the reflecting member by the mounting structure using the mounting member. A fixing device characterized by the fact that it has been done . In the fixing device according to any one of claims 1 to 3,
The mounting member is a fixing device characterized in that at least the reflective member is positioned with respect to the stay in the contact direction between the nip forming member and the contact member. In the fixing device according to any one of claims 1 to 4.
A fixing device characterized in that the reflecting member has a slope shape that reflects radiant heat radiated from the heating element in a direction not directed toward the heating element at a position on the reflecting surface facing the heating element. In the fixing device according to any one of claims 1 to 5,
The reflective member has holes at both ends in the width direction through which the mounting member penetrates, and one of the holes at both ends in the width direction is an elongated hole extending in the width direction. Fixing device. In the fixing device according to any one of claims 1 to 6.
A fixing device characterized in that, in the direction of contact of the contact member with the rotating body, the reflection member is attached to the stay at only one place. In the fixing device according to any one of claims 1 to 7.
The attachment member has a second portion fixed to the stay and a second portion having a diameter larger than that of the first portion and penetrating the reflective member and abutting on a surface of the stay orthogonal to the attachment direction of the attachment member. It has a portion and a third portion having a diameter larger than that of the second portion and a part of which faces the reflection surface side of the reflection member.
A fixing device characterized in that the thickness of the second part is set so that the third part has a predetermined gap with respect to the reflective member. In the fixing device according to any one of claims 1 to 8.
The stay has a contact portion with which the nip forming member comes into contact, and an upright portion that stands up from the contact portion toward the inside of the rotating body.
A fixing device characterized in that the heating element is arranged so as to face the side surface of the upright portion, and the reflective member is supported on the side surface of the upright portion. In the fixing device according to claim 9,
The mounting member moves in parallel to the side surface of the upright portion in the longitudinal direction of the reflective member, moves vertically away from the side surface by a predetermined distance, or moves at a predetermined angle with respect to the side surface. A fixing device characterized in that at least one of them is allowed and the reflective member is attached to the side surface. In the fixing device of claim 9 or 10.
The reflecting member is a fixing device having two flat surfaces parallel to the upright portion and different steps, and an inclined flat surface portion connecting the two flat surfaces. In the fixing device according to claim 9 or 10.
The reflective surface has a convex shape protruding from the reflective surface toward the heating element, and the reflective member is located between the heating element and the upright portion.
A fixing device characterized in that the reflective member is attached to the stay so that the center point of the heating element is located on an extension line in the convex projection direction. In the fixing device according to claim 12,
The fixing device having a convex shape having a chevron shape protruding from the reflective surface toward the heating element. In the fixing device according to claim 12,
The fixing device is characterized in that the convex shape is an arc shape protruding from the reflective surface toward the heating element. In an image forming apparatus including a toner image forming means for forming a toner image on a recording medium using toner and a fixing means for fixing the toner image on the recording medium by heating.
An image forming apparatus according to any one of claims 1 to 14 , wherein the fixing device is used as the fixing means.

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