JP6798363B2 - Fixing device and image forming device - Google Patents

Description

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

The fixing device of Patent Document 1 includes a transparent cylinder, an opposing member that cooperates with the transparent cylinder, a laser light irradiation device that irradiates the transparent cylinder with laser light, and a condensing member that collects the laser light. A liquid filler is provided between the transparent cylinder and the condensing member to fill a transparent liquid through which laser light can pass.

JP-A-2015-72351

There is a configuration in which a light source and a condensing member that rotates while in contact with the belt are arranged inside the belt on which the liquid adheres to the inner peripheral surface. In this configuration, the liquid adhering to the inner peripheral surface of the belt is transferred to the condensing member at the contact portion between the condensing member and the belt. Here, since the amount of liquid transferred to the condensing member is not controlled, the amount of liquid existing in the incident portion of the light of the condensing member fluctuates with the rotation of the condensing member. Then, the scattered state of the light incident on the condensing member from the light source changes as the amount of the liquid fluctuates. If the light scattering state changes, the fixability of the developer image may deteriorate.

The present invention includes a leveling member for leveling the liquid adhering to the condensing member in a configuration in which a light source and a condensing member that rotates while contacting the belt are arranged inside a belt with liquid adhering to the inner peripheral surface. The purpose is to suppress deterioration of the fixability of the developer image as compared with the configuration in which the developer image is not used.

The fixing device according to claim 1 of the present invention is a belt that is endless and transparent, has liquid adhered to an inner peripheral surface, and has an outer peripheral surface in contact with a developer image on a recording medium, and is arranged inside the belt. It has a light irradiation means for irradiating light, and a contact portion rotatably provided inside the belt and in contact with a part of the inner peripheral surface in a range of contact with the recording medium of the belt. It has a condensing member that condenses the light emitted from the means toward the contact portion, and a leveling member that evens out the liquid adhering to the condensing member.

The leveling member of the fixing device according to claim 2 of the present invention is on the downstream side of the contact portion in the rotation direction of the condensing member and on the upstream side of the incident portion of the light on the condensing member. Have been placed.

The leveling member of the fixing device according to claim 3 of the present invention is arranged to face the outer peripheral surface of the light collecting member along the axial direction of the light collecting member, and is a liquid adhering to the outer peripheral surface of the light collecting member. It is composed of a plate material that reduces the amount of light.

The leveling member of the fixing device according to claim 4 of the present invention has a replenishing member impregnated with a liquid and replenishing the liquid on the outer peripheral surface of the condensing member.

The light irradiating means of the fixing device according to claim 5 of the present invention has a plurality of light source portions arranged at set intervals set along the axial direction of the condensing member, and the leveling member is the collecting member. The shape of the portion of the leveling member that faces the outer peripheral surface of the light collecting member is such that the light collecting member and the leveling member are arranged so as to face the outer peripheral surface of the light collecting member along the axial direction of the optical member. When viewed from the tangential direction of the light collecting member, which is orthogonal to the direction in which the light sources are lined up, it has a wavy shape having a period equal to or less than the set interval.

The image forming apparatus according to claim 6 of the present invention has a forming means for forming a developer image on a recording medium and a developer image on a recording medium formed by the forming means is fixed on the recording medium. The fixing device according to any one of claims 5 and the like.

According to the first aspect of the present invention, in a configuration in which a light source and a condensing member that rotates while contacting the belt are arranged inside a belt on which liquid is adhered to an inner peripheral surface, the liquid adhering to the condensing member is leveled. It is possible to suppress deterioration of the fixability of the developer image as compared with the configuration having no member.

The invention of claim 2 can suppress deterioration of the fixability of the developer image as compared with the configuration in which the leveling member is arranged on the upstream side of the contact portion and on the downstream side of the light incident portion. ..

The invention of claim 3 can suppress an excessive amount of liquid at an incident portion of light of a condensing member, as compared with a configuration in which the amount of liquid is leveled without being reduced.

The invention of claim 4 can suppress the amount of liquid adhering to the outer peripheral surface of the condensing member from fluctuating in the axial direction, as compared with the configuration in which the leveling member does not have the replenishing member.

The invention of claim 5 diffuses light in the rotation axis direction of the condensing member as compared with a linear configuration when the shape of the portion of the leveling member facing the outer peripheral surface is viewed from the tangential direction of the condensing member. Can be made to.

The invention of claim 6 can suppress image defects after fixing as compared with the configuration without the fixing device according to any one of claims 1 to 5.

It is an overall block diagram which shows typically the image forming apparatus which concerns on 1st Embodiment. It is a block diagram which shows the fixing device which concerns on 1st Embodiment. It is explanatory drawing which shows the state which the leveling member was brought into contact with the nip formation roll which concerns on 1st Embodiment. It is explanatory drawing which shows the state which (A) the laser light incident on the belt and nip formation roll which concerns on 1st Embodiment is focused, and (B) the belt and a nip are formed from the plurality of light source portions which concern on 1st Embodiment. It is explanatory drawing which shows the state which the laser light is incident on a roll. It is explanatory drawing which shows the state which the leveling member was brought into contact with the nip formation roll which concerns on 2nd Embodiment. It is explanatory drawing which shows the state which (A) the laser light incident on the belt and nip formation roll which concerns on 2nd Embodiment is focused, and (B) the belt and a nip are formed from the plurality of light source portions which concern on 2nd Embodiment. It is explanatory drawing which shows the state which the laser light is incident on a roll. It is explanatory drawing which shows the state which brought the blade and the web into contact with the nip formation roll which concerns on 3rd Embodiment. It is explanatory drawing which shows the state which brought the web into contact with the nip formation roll in the fixing apparatus which concerns on a modification.

[First Embodiment]
An example of the fixing device and the image forming device according to the first embodiment will be described.

〔overall structure〕
FIG. 1 shows the image forming apparatus 10 of the first embodiment. As an example, the image forming apparatus 10 is formed by a conveying unit 12 that conveys the paper P, an image forming unit 14 that forms a toner image G on the conveyed paper P by using toner T, and an image forming unit 14. It has a fixing device 20 for fixing the toner image G on the paper P. Paper P is an example of a recording medium. Toner T is an example of a developer. The toner image G is an example of a developer image. The image forming unit 14 is an example of the forming means. Further, the image forming unit 14 is adapted to perform each step of charging, exposure, development, transfer, and cleaning. In the fixing device 20, as an example, the paper P is conveyed from the −X side to the X side.

In the following description, the direction indicated by the arrow Y in FIG. 1 is the height direction of the image forming apparatus 10, and the direction indicated by the arrow X in FIG. 1 is the width direction. Further, the direction (indicated by Z) orthogonal to each of the height direction and the width direction is defined as the depth direction. Then, when the image forming apparatus 10 is viewed from the side where the user (not shown) stands (when viewed from the front), the width direction, the height direction, and the depth direction are described as the X direction, the Y direction, and the Z direction. Further, when it is necessary to distinguish one side and the other side of each of the X direction, the Y direction, and the Z direction, the image forming apparatus 10 is viewed from the front, the upper side is the Y side, the lower side is the −Y side, and the right side is the right side. The X side, the left side is described as -X side, the back side (rear side) is described as Z side, and the front side is described as -Z side.

[Main part composition]
Next, the fixing device 20 will be described.

As shown in FIG. 2, the fixing device 20 includes a belt 22, a light source unit 24 as an example of light irradiation means, a nip forming roll 26 as an example of a light collecting member, and a leveling member 28. Further, the fixing device 20 has support rolls 32, 33, 34, an opposing roll 35, a pressure roll 36, and an oil coating member 38. The support rolls 32, 33, and 34 are rotatably provided inside the belt 22 with the Z direction as the axial direction, and support the belt 22. The opposing roll 35 is provided on the outside of the belt 22 at a position facing the support roll 34, and is rotatable with the Z direction as the axial direction. The pressurizing roll 36 is rotatably provided on the outside of the belt 22 with the Z direction as the axial direction, and pressurizes the belt 22 toward the nip forming roll 26 described later.

<Belt>
The belt 22 is endless and transparent, and transmits the laser beam Bm from the light source unit 24, which will be described later. In FIG. 2, the laser beam Bm is simplified and shown by one solid line. The definition of "transparency" will be described later. Further, as an example, the belt 22 has a four-layer structure having an elastic layer, a base material layer, an intermediate layer, and a release layer (not shown). A primer layer (not shown) for enhancing adhesiveness is formed between the elastic layer, the base material layer, the intermediate layer, and the release layer. Silicone oil OL (see FIG. 3B) as an example of the liquid adheres to the inner peripheral surface 22A of the belt 22 by the oil coating member 38 described later. The outer peripheral surface 22B of the belt 22 comes into contact with the toner image G on the paper P.

(Elastic layer)
The elastic layer is the innermost layer arranged on the innermost side (inside) of the nip forming roll 26 of the belt 22, and is exposed. Further, as an example, the elastic layer is made of silicone rubber thicker than the base material layer described later, and transmits the laser beam Bm. The "elastic layer" in the present embodiment is a layer that is more elastically deformed in the thickness direction than the base material layer when pressed in the nip portion N described later. Examples of materials other than silicone rubber include chloroprene rubber, butyl rubber, acrylic rubber, urethane rubber, nitrile rubber, fluororubber, and styrene-butadiene rubber.

(Base layer)
The base material layer is a layer for maintaining the required strength as the belt 22. Further, the base material layer is made of polyimide as an example, and transmits laser light Bm. Examples of materials that can be used other than polyimide include polyvinylidene fluoride (PVDF), polyethylene (PE), polyurethane (PU), and polydimethylsiloxane (PDMS). Examples of materials that can be used other than polyimide include polyetheretherketone (PEEK), polyethersulfone (PES), fluorinated ethylenepropylene (FEP), and ethylenetetrafluoroethylene copolymer (ETFE). Further, examples of materials that can be used other than polyimide include chlorotrifluoroethylene (CTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and polytetrafluoroethylene (PTFE). The base material layer may be composed of a combination of the above materials.

(Middle layer)
As an example, the intermediate layer is made of silicone rubber and transmits laser light Bm. In this embodiment, as an example, the elastic layer and the intermediate layer are made of the same material (silicone rubber).

(Release layer)
As an example, the release layer is composed of a tetrafluoroethylene perfluoroalkoxy ethylene copolymer (PFA) and transmits laser light Bm. Further, the release layer suppresses the adhesion of the toner image G to the belt 22 as compared with the configuration without the release layer. Other materials constituting the release layer include, for example, fluorinated ethylene polymer (PTFE), fluorinated ethylene hexafluoride propylene copolymer (FEP), and ethylene tetrafluoroethylene copolymer (ETFE). .. The release layer also has a function of giving a preferable gloss to the toner image G after fixing in cooperation with the intermediate layer.

Further, the belt 22 is wound around the support rolls 32, 33, 34 and the nip forming roll 26 described later. The belt 22 orbits the support roll 32 by being rotationally driven by a gear and a motor (not shown). Here, the portion where the belt 22 and the paper P are sandwiched between the nip forming roll 26 and the pressurizing roll 36, which will be described later, and the toner image G is pressurized is referred to as a nip portion N. The nip portion N is a portion where the toner image G on the paper P is heated by the laser beam Bm from the light source unit 24 described later. Then, the belt 22 transmits the laser beam Bm at the nip portion N and comes into contact with the toner image G on the paper P.

<Oil coating member>
As an example, the oil coating member 38 is configured by impregnating a non-woven fabric formed in a rectangular shape with the Z direction as the longitudinal direction and the X direction as the lateral direction impregnated with silicone oil OL. Further, the oil coating member 38 is provided on the upstream side of the nip portion N in the circumferential movement direction of the belt 22 and on the downstream side of the support roll 34. The end of the oil coating member 38 is supported by a bracket (not shown), and the end on the −X side is in contact with the inner peripheral surface 22A of the belt 22.

Here, when the belt 22 is moved around, the silicone oil OL of the oil coating member 38 is applied (supplied) to the inner peripheral surface 22A. Since the amount of silicone oil OL is not controlled in the oil coating member 38, the amount of silicone oil OL applied to the inner peripheral surface 22A may vary in the Z direction.

<Light source unit>
In the present embodiment, as an example, the longitudinal direction of the light source unit 24 is the Z direction, the direction in which the laser beam Bm is applied to the toner image G is orthogonal to the Y direction, the Z direction, and the Y direction, and the direction in which the paper P is conveyed is Each member is arranged so as to be in the X direction. As an example, the light source unit 24 has a plurality of laser arrays 42 (see FIG. 4B) as an example of the plurality of light source units, and a beam shaping unit 44. Further, the light source unit 24 is arranged inside the belt 22 and irradiates the laser beam Bm toward the −Y side so that the laser beam Bm is incident on the nip forming roll 26 described later. Then, the light source unit 24 irradiates the toner image G with the laser beam Bm at the nip portion N through the nip forming roll 26 and the belt 22. The laser beam Bm is an example of light.

As shown in FIG. 4 (B), as an example, the plurality of laser arrays 42 are arranged at a set interval d set along the Z direction when viewed from the X direction. The distance from the center of the laser array 42 in the Z direction to the center of the adjacent laser array 42 in the Z direction is set as the setting interval d. Each of the plurality of laser arrays 42 is configured to emit laser light Bm toward the −Y side (nip forming roll 26 side). The plurality of laser arrays 42 are arranged so that the laser light Bm is diffused in the Z direction and the laser light Bm from the adjacent laser arrays 42 partially overlaps in the Z direction when viewed from the X direction. There is.

The beam shaping unit 44 shown in FIG. 4A regards the laser light Bm emitted from the plurality of laser arrays 42 (see FIG. 4B) toward the −Y side as parallel light when viewed from the Z direction. It has a collimated lens (not shown). In FIG. 4A, the illustration of the silicone oil OL adhering to the inner peripheral surface 22A after the pressure roll 36 (see FIG. 2) and the nip portion N is omitted. As shown in FIG. 4B, when the beam shaping unit 44 is viewed from the X direction, the laser beam Bm is diffused in the Z direction.

<Nip forming roll>
As an example, the nip forming roll 26 shown in FIG. 2 is composed of a transparent glass roll which is a columnar (solid) rod lens. Further, the nip forming roll 26 is rotatably provided inside the belt 22 on the −Y side with respect to the light source unit 24 and on the Y side of the transport path K to which the paper P is transported, with the Z direction as the axial direction. .. The outer peripheral surface 26A of the nip forming roll 26 comes into contact with a part of the inner peripheral surface 22A of the belt 22 in the absence of the silicone oil OL. Further, the nip forming roll 26 transmits the laser light Bm emitted from the light source unit 24 and concentrates the laser light Bm toward the contact portion 29 and the nip portion N, which will be described later, when viewed from the Z direction. It is configured in. The optical axis of the laser beam Bm passes through the center of the nip forming roll 26 when the nip forming roll 26 is viewed from the Z direction.

The portion of the outer peripheral surface 26A of the nip forming roll 26 on which the laser beam Bm is incident is referred to as an incident portion 27. The incident portion 27 is a range (site) including the top of the nip forming roll 26 on the Y side in the Y direction when the nip forming roll 26 is viewed from the Z direction. On the other hand, a portion of the outer peripheral surface 26A that deviates from the incident portion 27 by 180 ° is referred to as a contact portion 29. The contact portion 29 is a portion where the outer peripheral surface 26A and a part of the inner peripheral surface 22A in the circumferential direction in the range of contact with the paper P of the belt 22 come into contact with each other.

The “transparency” of the belt 22 and the nip forming roll 26 in the present embodiment means that the transmittance is sufficiently high in the wavelength range of the laser beam Bm. That is, the belt 22 and the nip forming roll 26 may be those that transmit the laser beam Bm, and from the viewpoint of light utilization efficiency, the higher the transmittance, the better. As an example, the transmittance is preferably 90% or more, preferably 95% or more.

<Pressurized roll>
As an example, the pressure roll 36 shown in FIG. 2 has an elastic layer and a release layer (not shown) formed on the outer peripheral surface of a stainless steel roll. Further, the pressure roll 36 is rotatably provided on the −Y side with respect to the transport path K on which the paper P is transported, with the Z direction as the axial direction. Further, the pressure roll 36 is arranged so that a predetermined pressing force acts between the pressure roll 36 and the nip forming roll 26. In this way, the pressurizing roll 36 sandwiches the paper P on which the toner image G is formed and the belt 22 together with the nip forming roll 26, pressurizes the paper P, and conveys the pressure to the X side. In other words, the pressure roll 36 pressurizes the toner image G and the belt 22 on the paper P toward the nip forming roll 26 to form the nip portion N. As a result, the toner image G is heated and pressurized by the laser beam Bm at the nip portion N, and is fixed to the paper P.

<Leveling member>
As shown in FIG. 3, the leveling member 28 is formed in the shape of a rectangular flat plate elongated in the Z direction. In other words, the leveling member 28 is made of a plate material (blade). Further, the leveling member 28 is made of a rubber material having excellent oil resistance and abrasion resistance, and is made of fluororubber as an example. Further, the leveling member 28 is arranged to face the outer peripheral surface 26A along the Z direction (axial direction) of the nip forming roll 26.

Specifically, the leveling member 28 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. Further, in the leveling member 28, one end side in the lateral direction is fixed to a bracket (not shown) over the entire length in the Z direction, and the other end side (free end side) is in the direction opposite to the rotation direction of the nip forming roll 26. It is arranged to face the outer peripheral surface 26A of the nip forming roll 26 so as to face.

In FIG. 3, in order to clearly show the contact portion between the leveling member 28 and the outer peripheral surface 26A, the angle of the leveling member 28 with respect to the outer peripheral surface 26A is in the forward direction with respect to the rotation direction of the nip forming roll 26. It is shown in a state where it is arranged at an angle. Actually, the leveling member 28 is arranged so that the angle of the leveling member 28 with respect to the outer peripheral surface 26A is opposite to the rotation direction of the nip forming roll 26. The pressure acting on the contact portion between the leveling member 28 and the outer peripheral surface 26A is set to such a pressure that the leveling member 28 does not damage the outer peripheral surface 26A. Further, this pressure is almost the same in the Z direction.

The leveling member 28 configured in this way reduces the thickness of the silicon oil OL adhering to the outer peripheral surface 26A of the nip forming roll 26, and as the nip forming roll 26 rotates, the circumferential direction (rotation direction) and Z It is designed to level in the direction. Further, the leveling member 28 also has a function of reducing the amount of excess silicone oil OL adhering to the outer peripheral surface 26A to a preset amount.

(About refraction of laser light)
Here, the refractive index of air light is about 1.0 (see JIS B 7071-1). Further, the refractive index of light of silicon oil OL is about 1.4 (general measurement value by a refractometer). That is, since the difference in the refractive index of the light between the air and the silicon oil OL is large, the laser light Bm is likely to be scattered when it is incident on the silicon oil OL from the air. Therefore, if the amount of silicon oil OL adhering to the outer peripheral surface 26A and the surface state are different in the Z direction, the condensing state of the laser beam Bm in the nip portion N will be different in the Z direction. As a reference, the refractive index of light of the nip forming roll 26 is about 1.5 (see JIS B 7071-1).

[Action]
Next, the operation of the first embodiment will be described.

In the fixing device 20 shown in FIG. 2, the laser beam Bm emitted from the light source unit 24 toward the nip forming roll 26 is collected by the nip forming roll 26 and incident on the nip portion N through the belt 22. Then, in the nip portion N, the laser beam Bm is absorbed by the toner T (see FIG. 1) constituting the toner image G on the paper P. As a result, the toner image G is heated and pressurized by the pressing force acting on the nip portion N, and is fixed to the paper P.

Further, in the fixing device 20, a part of the silicone oil OL adhering to the inner peripheral surface 22A of the belt 22 is transferred to the nip forming roll 26 at the contact portion 29 between the nip forming roll 26 and the belt 22. Then, the silicon oil OL transferred to the nip forming roll 26 moves toward the incident portion 27 as the nip forming roll 26 rotates.

Here, the silicone oil OL is leveled by the leveling member 28 before reaching the incident portion 27. Specifically, the silicone oil OL enters between the nip forming roll 26 and the leveling member 28 as the nip forming roll 26 rotates, so that an excess amount is scraped off (the amount of adhesion is reduced). ). In other words, the amount of the silicone oil OL adhered is leveled in the rotation direction of the nip forming roll 26. Further, since the silicone oil OL is pressurized toward the nip forming roll 26 by the leveling member 28, it spreads in the Z direction orthogonal to the rotation direction of the nip forming roll 26. That is, if there is a portion of the outer peripheral surface 26A of the nip forming roll 26 in the Z direction in which the amount of silicone oil OL adhered is small, the silicone oil OL adheres to this small portion as well.

As described above, in the fixing device 20, the leveling member 28 scrapes off an excess amount of the silicone oil OL, and makes the amount of the silicone oil OL adhered to the nip forming roll 26 about the same in the Z direction (leveling). .. Therefore, the fluctuation of the amount of silicone oil OL reaching the incident portion 27 (the fluctuation of the amount in the Z direction and the rotation direction of the nip forming roll 26) is suppressed as compared with the configuration without the leveling member 28. .. As a result, it is suppressed that the amount of light of the laser light Bm scattered by the silicon oil OL at the incident portion 27 differs in the Z direction, so that the laser light Bm focused on the belt 22 as the nip forming roll 26 rotates. Fluctuations in the amount of light are suppressed.

Then, in the fixing device 20, the light amount of the laser light Bm focused on the belt 22 is suppressed from fluctuating with the rotation of the nip forming roll 26, so that the light collecting property of the laser light Bm on the toner T is suppressed. Is suppressed from decreasing. In other words, it is suppressed that the heating temperature of the toner T is lower than the set fixing temperature. As a result, the amount of heat required for fixing is given to the toner T, so that deterioration of the fixability of the toner image G on the paper P is suppressed as compared with the configuration without the leveling member 28. The deterioration of the fixability means that the toner image G is locally poorly fixed or the glossiness is uneven, and examples thereof include a cold offset of the toner image G.

Further, in the fixing device 20, the leveling member 28 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. Therefore, even when the variation in the amount of the silicone oil OL transferred from the belt 22 to the nip forming roll 26 in the contact portion 29 is large in the Z direction and the rotation direction, the silicone oil leveled by the leveling member 28 The OL reaches the incident portion 27. As a result, the amount of light of the laser beam Bm focused on the belt 22 may fluctuate as compared with the configuration in which the leveling member 28 is arranged on the upstream side of the contact portion 29 and on the downstream side of the incident portion 27. It is suppressed. Then, deterioration of the fixability of the toner image G on the paper P is suppressed.

Further, in the fixing device 20, the leveling member 28 is arranged so as to face the outer peripheral surface 26A along the Z direction, and is composed of a plate material (blade) that reduces the silicon oil OL adhering to the outer peripheral surface 26A. Therefore, the amount of silicone oil OL on the outer peripheral surface 26A on the downstream side of the leveling member 28 is smaller than the amount of silicone oil OL on the upstream side. As a result, it is possible to prevent the amount of silicone oil OL from becoming excessive at the incident portion 27, as compared with the configuration in which the amount of silicone oil OL is leveled without being reduced.

In the image forming apparatus 10 shown in FIG. 1, deterioration of the fixability of the toner image G in the fixing device 20 is suppressed, so that image defects (for example, deterioration of image glossiness) after fixing are suppressed.

As a means of grasping the amount of light focused on the belt 22, it can be determined from the two-dimensional light amount distribution observed by a camera (CCD or the like) that focuses on the focused position of the belt 22. Another method of indirectly grasping the amount of light is to place a thermal paper or the like at the condensing position of the belt 22 and judge from the color change due to laser irradiation and the width thereof.

[Second Embodiment]
Next, an example of the fixing device and the image forming device according to the second embodiment will be described. The same members and parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

FIG. 5 shows a part of the fixing device 50 of the second embodiment. The fixing device 50 has a configuration in which the leveling member 52 is provided in place of the leveling member 28 (see FIG. 2) in the fixing device 20 (see FIG. 2). The configuration other than the leveling member 52 is the same as that of the fixing device 20.

<Leveling member>
As an example, the leveling member 52 is composed of a fluororubber blade formed in a long flat plate shape in the Z direction. Further, the leveling member 52 is arranged so as to face the outer peripheral surface 26A along the Z direction. Further, the leveling member 52 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. In addition, the leveling member 52 is fixed so that one end side in the lateral direction is fixed to a bracket (not shown) and the other end side (free end side) faces the direction opposite to the rotation direction of the nip forming roll 26. It is in contact with the outer peripheral surface 26A of the forming roll 26.

In FIG. 5, in order to clearly show the contact portion between the leveling member 52 and the outer peripheral surface 26A, the angle of the leveling member 52 with respect to the outer peripheral surface 26A is in the forward direction with respect to the rotation direction of the nip forming roll 26. It is shown in a state where it is arranged at an angle. The pressure acting on the contact portion between the leveling member 52 and the outer peripheral surface 26A is set to such a pressure that the leveling member 52 does not damage the outer peripheral surface 26A. Further, this pressure is almost the same in the Z direction.

Further, in the leveling member 52, a portion facing the outer peripheral surface 26A (hereinafter, referred to as an end portion 52A) is formed in a wavy shape. Specifically, the shape of the end portion 52A is, for example, when viewed from the tangential direction of the nip forming roll 26 orthogonal to the direction in which the nip forming roll 26 and the leveling member 52 are arranged, of the plurality of laser arrays 42. It has a sinusoidal shape with a period equal to or less than the set interval d (see FIG. 4B). The setting interval d is the pitch of the plurality of laser arrays 42. This sine wave has a shape in which peaks and valleys in the X direction are periodically repeated in the Z direction. Assuming that the length of the end portion 52A from the mountain portion to the mountain portion in the Z direction (the length from the valley to the valley in the Z direction) is L1, L1 <d. In addition, L1 = d may be set.

[Action]
Next, the operation of the second embodiment will be described.

In the fixing device 50 shown in FIG. 6A, the laser beam Bm emitted from the light source unit 24 toward the nip forming roll 26 is collected by the nip forming roll 26 and incident on the nip portion N through the belt 22. Then, in the nip portion N, the laser beam Bm is absorbed by the toner T on the paper P. As a result, the toner image G is heated and pressurized by the pressing force acting on the nip portion N, and is fixed to the paper P. Further, in the fixing device 50, the silicon oil OL transferred to the nip forming roll 26 at the contact portion 29 moves toward the incident portion 27 as the nip forming roll 26 rotates. In FIG. 6A, the illustration of the silicone oil OL adhering to the inner peripheral surface 22A after the pressure roll 36 (see FIG. 2) and the nip portion N is omitted.

Here, the silicone oil OL is leveled by the leveling member 52 before reaching the incident portion 27. Specifically, the silicone oil OL enters between the nip forming roll 26 and the leveling member 52 as the nip forming roll 26 rotates, so that an excess amount is scraped off (the amount of adhesion is reduced). ). In other words, the amount of the silicone oil OL adhered is leveled in the rotation direction of the nip forming roll 26. Further, since a part of the silicone oil OL is pressed toward the nip forming roll 26 by the leveling member 52, it spreads in the Z direction orthogonal to the rotation direction of the nip forming roll 26. That is, if there is a portion of the outer peripheral surface 26A of the nip forming roll 26 in the Z direction in which the amount of silicone oil OL adhered is small, the silicone oil OL adheres to this small portion as well.

In this way, in the fixing device 50, the leveling member 52 scrapes off an excess amount of silicone oil OL, and the amount of silicone oil OL adhered to the nip forming roll 26 is set to be about the same in the Z direction. Therefore, the fluctuation of the amount of silicon oil OL reaching the incident portion 27 (the fluctuation in the Z direction and the rotation direction of the nip forming roll 26) is suppressed as compared with the configuration without the leveling member 52. As a result, fluctuations in the amount of laser light Bm scattered by the silicon oil OL at the incident portion 27 are suppressed, so that the amount of light of the laser light Bm focused on the belt 22 as the nip forming roll 26 rotates. Is suppressed from fluctuating.

Then, in the fixing device 50, the light amount of the laser light Bm focused on the belt 22 is suppressed from fluctuating with the rotation of the nip forming roll 26, so that the light collecting property of the laser light Bm on the toner T is suppressed. Is suppressed from decreasing. In other words, it is suppressed that the heating temperature of the toner T is lower than the set fixing temperature. As a result, the amount of heat required for fixing is given to the toner T, so that deterioration of the fixability of the toner image G on the paper P is suppressed as compared with the configuration without the leveling member 52. The deterioration of fixability is as described above.

Further, in the fixing device 50, the leveling member 52 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. Therefore, even when the variation in the amount of the silicone oil OL transferred from the belt 22 to the nip forming roll 26 in the contact portion 29 is large in the Z direction and the rotation direction, the silicone oil leveled by the leveling member 52 The OL reaches the incident portion 27. As a result, the amount of light of the laser beam Bm focused on the belt 22 may fluctuate as compared with the configuration in which the leveling member 52 is arranged on the upstream side of the contact portion 29 and on the downstream side of the incident portion 27. It is suppressed. Then, deterioration of the fixability of the toner image G on the paper P is suppressed.

Further, in the fixing device 50, the leveling member 52 is arranged to face the outer peripheral surface 26A along the Z direction, and is composed of a blade that reduces the silicon oil OL adhering to the outer peripheral surface 26A. Therefore, since the pressure of the portion in contact with the outer peripheral surface 26A is substantially the same in the Z direction, the silicone oil OL adhering to the outer peripheral surface 26A is compared with the configuration in which the leveling member 52 is provided in a part of the Z direction. It is suppressed that the amount of is excessive in a part in the Z direction.

In addition, as shown in FIG. 5, in the fixing device 50, the shape of the end portion 52A of the leveling member 52 facing the outer peripheral surface 26A has a period equal to or less than the set interval d (see FIG. 6B). It is formed in a wavy shape. Therefore, a force acting toward the Z side and the −Z side with respect to the rotation direction of the nip forming roll 26 acts on the silicon oil OL in contact with the mountain portion of the end portion 52A. Then, in the silicon oil OL, a high peak portion in the radial direction (X direction) and a low valley portion in the radial direction are formed at intervals in the Z direction, in other words, the nip formation. Silicon oil OL is applied to the outer peripheral surface 26A of the roll 26 in a plurality of streaks.

As shown in FIG. 6B, in the peaks and valleys of the silicon oil OL, the laser beam Bm incident on the silicon oil OL is refracted according to the surface shape of the peaks and valleys. Specifically, the laser beam Bm incident on the silicon oil OL is refracted in the Z direction. As a result, in the fixing device 50 shown in FIG. 5, the shape of the portion of the leveling member 52 facing the outer peripheral surface 26A is linearly configured along the Z direction when viewed from the tangential direction of the nip forming roll 26. In comparison, the laser beam Bm is diffused in the Z direction.

The fact that the laser beam Bm is diffused in the Z direction means that it is not necessary to increase the optical path length from the laser array 42 to the nip forming roll 26 to diffuse the laser beam Bm in the Z direction. In other words, in the fixing device 50, it is not necessary to increase the optical path length from the laser array 42 (see FIG. 6B) to the nip forming roll 26 in order to secure the amount of overlapping the laser light Bm in the Z direction. The fixing device 50 is downsized as compared with the configuration in which the optical path length is lengthened.

In the fixing device 50, the silicone oil OL is applied to the outer peripheral surface 26A in a streak shape, but the streaks of the silicone oil OL have periodicity in the Z direction. Therefore, by adjusting the arrangement of the laser array 42 in advance according to this periodicity, it is possible to suppress the amount of light of the laser light Bm focused on the nip portion N from fluctuating in the Z direction.

In the image forming apparatus 10 (see FIG. 1) having the fixing device 50, deterioration of the fixing property of the toner image G in the fixing device 50 is suppressed, so that image defects after fixing (for example, reduction in glossiness of the image) are suppressed. Will be done.

[Third Embodiment]
Next, an example of the fixing device and the image forming device according to the third embodiment will be described. The same members and parts as those of the first and second embodiments described above are designated by the same reference numerals as those of the first and second embodiments, and the description thereof will be omitted.

FIG. 7 shows a part of the fixing device 60 of the third embodiment. The fixing device 60 has a configuration in which the leveling member 62 is provided in place of the leveling member 28 (see FIG. 2) in the fixing device 20 (see FIG. 2). The configuration other than the leveling member 62 is the same as that of the fixing device 20.

<Leveling member>
As an example, the leveling member 62 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. Further, the leveling member 62 is arranged so as to face the outer peripheral surface 26A along the Z direction. Further, the leveling member 62 is configured to have a blade 64 and a web 66 as an example of a replenishment member. Since the blade 64 has the same configuration as the leveling member 52 (see FIG. 5), the description thereof will be omitted.

In FIG. 7, in order to clearly show the contact portion between the blade 64 and the web 66 and the outer peripheral surface 26A, the angle of the blade 64 and the web 66 with respect to the outer peripheral surface 26A is in the forward direction with respect to the rotation direction of the nip forming roll 26. It is shown in a state where it is arranged at an angle of. The pressure acting on the contact portion between the blade 64 and the web 66 and the outer peripheral surface 26A is set to such a pressure that the blade 64 and the web 66 do not damage the outer peripheral surface 26A. Further, this pressure is almost the same in the Z direction.

(web)
The web 66 has a structure in which a strip-shaped (sheet-shaped) fiber body is impregnated with silicone oil OL. The impregnation amount of silicone oil OL in the web 66 is smaller than the impregnation amount of silicone oil OL in the oil coating member 38 (see FIG. 2). Further, as an example, the web 66 is formed in a rectangular shape with the Z direction as the longitudinal direction and the X direction as the lateral direction. Further, the web 66 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the blade 64. In other words, the blade 64 is arranged on the downstream side of the web 66 and on the upstream side of the incident portion 27. Further, the web 66 is arranged so as to face the outer peripheral surface 26A along the Z direction.

The web 66 has a nip so that one end on the X side is supported by a bracket (not shown) and the end on the −X side (the end on the free end side) faces in the direction opposite to the rotation direction of the nip forming roll 26. It is in contact with the outer peripheral surface 26A of the forming roll 26. Further, the web 66 is arranged to face the outer peripheral surface 26A along the Z direction.

[Action]
Next, the operation of the third embodiment will be described.

In the fixing device 60, the laser beam Bm emitted from the light source unit 24 (see FIG. 2) toward the nip forming roll 26 is collected by the nip forming roll 26 and incident on the nip portion N through the belt 22. Then, in the nip portion N, the laser beam Bm is absorbed by the toner T (see FIG. 2) on the paper P. As a result, the toner image G is heated and pressurized by the pressing force acting on the nip portion N (see FIG. 2), and is fixed to the paper P. Further, in the fixing device 60, the silicon oil OL transferred to the nip forming roll 26 at the contact portion 29 moves toward the incident portion 27 as the nip forming roll 26 rotates.

Here, the silicone oil OL is leveled by the leveling member 62 before reaching the incident portion 27. Specifically, first, the web 66 replenishes the outer peripheral surface 26A of the nip forming roll 26 with silicone oil OL. Specifically, when the silicone oil OL is transferred from the belt 22 to the nip forming roll 26, if there is a part where the amount of the silicone oil OL is small in the Z direction, the silicone oil OL is replenished to this part. Will be done. Therefore, a certain amount of silicone oil OL adheres to the outer peripheral surface 26A before leveling with the blade 64, so that the difference in the amount of silicone oil OL adhered in the Z direction becomes small. As a result, the amount of silicone oil OL adhering to the outer peripheral surface 26A on the downstream side of the leveling member 62 varies in the Z direction (axial direction) as compared with the configuration in which the leveling member 62 does not have the web 66. Is suppressed.

Subsequently, the silicone oil OL enters between the nip forming roll 26 and the blade 64 as the nip forming roll 26 rotates, so that an excess amount is scraped off (the amount of adhesion is reduced). In other words, the amount of the silicone oil OL adhered is leveled in the rotation direction of the nip forming roll 26. Further, a part of the silicone oil OL is pressed toward the nip forming roll 26 by the blade 64, so that it spreads in the Z direction. As described above, in the fixing device 60, the leveling member 62 replenishes the silicone oil OL and makes the amount of the silicone oil OL adhered to the nip forming roll 26 about the same in the Z direction. Therefore, the fluctuation of the amount of silicon oil OL reaching the incident portion 27 (the fluctuation in the Z direction and the rotation direction of the nip forming roll 26) is suppressed as compared with the configuration without the leveling member 62. As a result, fluctuations in the amount of laser light Bm scattered by the silicon oil OL at the incident portion 27 are suppressed, so that the light is focused on the belt 22 (see FIG. 2) as the nip forming roll 26 rotates. Fluctuations in the amount of laser light Bm are suppressed.

Then, in the fixing device 60, the light amount of the laser light Bm focused on the belt 22 is suppressed from fluctuating with the rotation of the nip forming roll 26, so that the light collecting property of the laser light Bm on the toner T is suppressed. Is suppressed from decreasing. In other words, it is suppressed that the heating temperature of the toner T is lower than the set fixing temperature. As a result, the amount of heat required for fixing is given to the toner T, so that deterioration of the fixability of the toner image G on the paper P is suppressed as compared with the configuration without the leveling member 62. The deterioration of fixability is as described above.

Further, in the fixing device 60, the leveling member 62 is arranged on the downstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 and on the upstream side of the incident portion 27. Therefore, even when the variation in the amount of the silicone oil OL transferred from the belt 22 to the nip forming roll 26 in the contact portion 29 is large in the Z direction and the rotation direction, the silicone oil leveled by the leveling member 62. The OL reaches the incident portion 27. As a result, the amount of light of the laser beam Bm focused on the belt 22 may fluctuate as compared with the configuration in which the leveling member 62 is arranged on the upstream side of the contact portion 29 and on the downstream side of the incident portion 27. It is suppressed. Then, deterioration of the fixability of the toner image G on the paper P is suppressed.

In the image forming apparatus 10 (see FIG. 1) having the fixing device 60, deterioration of the fixing property of the toner image G in the fixing device 60 is suppressed, so that image defects after fixing (for example, reduction in glossiness of the image) are suppressed. Will be done.

The present invention is not limited to the above embodiment.

<Modification example>
As shown in FIG. 8, in the fixing device 60, except for the blade 64 (see FIG. 7), the leveling member 62 may be formed of a web 66 formed in a blade shape. Since the web 66 is configured in a blade shape, it not only has a function of supplying silicon oil OL to the outer peripheral surface 26A, but also smoothes the silicon oil OL on the outer peripheral surface 26A in the circumferential direction (rotational direction) and the Z direction. It also has a function. Further, the end portion of the web 66 on the nip forming roll 26 side may be formed in a wavy shape. Further, the wavy period may be set to a period equal to or less than the set interval d (see FIG. 4B). If it is desired to further diffuse the laser beam Bm in the Z direction, the blade 64 may be arranged as described above. Further, in the fixing device 20 (see FIG. 2) and the fixing device 50 (see FIG. 5), the leveling members 28 and 52 may be formed of a web 66 formed in a blade shape or a wavy shape.

<Other variants>
The leveling members 28, 52, 62 are on the upstream side of the contact portion 29 in the rotation direction of the nip forming roll 26 (on the upstream side of the portion where the nip forming roll 26 and the belt 22 contact) and downstream of the incident portion 27. It may be arranged on the side. By pre-leveling the outer peripheral surface 26A of the nip forming roll 26 that rotates toward the contact portion 29 before the silicone oil OL adheres, the amount of the silicone oil OL adhering to the outer peripheral surface 26A is suppressed from varying in the Z direction. To.

Further, the leveling members 28, 52, 62 may be arranged so that the other end side (free end side) faces the forward direction (same direction) with respect to the rotation direction of the nip forming roll 26. Further, a collecting portion such as a container for collecting the silicone oil OL may be provided around the leveling members 28, 52, 62.

In the fixing device 20, the leveling member 28 may be composed of the web 66. In the fixing device 50, the corrugated period of the end portion 52A of the leveling member 52 may be larger than the set interval d of the plurality of laser arrays 42. This is because the silicone oil OL is leveled in the Z direction by the peaks and valleys.

The nip forming roll 26 is not limited to a solid one, and may be a hollow one as long as the laser beam Bm can be focused (converged) toward the nip portion N. Further, the nip forming roll 26 is not limited to glass, and may be made of resin such as acrylic.

The method of applying the silicone oil OL to the inner peripheral surface 22A of the belt 22 is not limited to the method of constantly applying the silicone oil OL using the oil coating member 38. A method may be adopted in which the silicone oil OL is applied to the inner peripheral surface 22A at the time of assembling the fixing devices 20, 50, 60 (at the time of manufacturing at the factory) without using the oil coating member 38. The oil coating member 38 is not limited to a blade shape, and may be a roll. The liquid is not limited to silicone oil, and other lubricating oils may be used.

10 Image forming apparatus 14 Image forming unit (example of forming means)
20 Fixing device 22 Belt 22A Inner peripheral surface 24 Light source unit (example of light irradiation means)
26 Nip forming roll (example of light collecting member)
26A Outer surface 28 Leveling member 29 Contact part 42 Laser array (Example of light source part)
50 Fixing device 52 Leveling member 60 Fixing device 62 Leveling member 66 Web (Example of replenishment member)
OL Silicone Oil (Example of Liquid)

Claims (6)

A belt that is endless and transparent, with liquid adhering to the inner peripheral surface and the outer peripheral surface in contact with the developer image on the recording medium.
A light irradiation means arranged inside the belt and irradiating light,
The contact portion is rotatably provided inside the belt, has a contact portion that contacts a part of the inner peripheral surface in a range that contacts the recording medium of the belt, and emits light emitted from the light irradiation means. A condensing member that condenses light toward
A leveling member for leveling the liquid adhering to the light collecting member and
Fixing device having. The fixing according to claim 1, wherein the leveling member is arranged on the downstream side of the contact portion in the rotation direction of the condensing member and on the upstream side of the incident portion of the light on the condensing member. apparatus. The leveling member is arranged so as to face the outer peripheral surface of the condensing member along the axial direction of the condensing member, and is composed of a plate material that reduces the amount of liquid adhering to the outer peripheral surface of the condensing member. The fixing device according to claim 1 or 2. The fixing device according to any one of claims 1 to 3, wherein the leveling member is impregnated with a liquid and has a replenishing member for replenishing the liquid on an outer peripheral surface of the condensing member. The light irradiating means has a plurality of light source units arranged at set intervals set along the axial direction of the condensing member.
The leveling member is arranged so as to face the outer peripheral surface of the light collecting member along the axial direction of the light collecting member.
When the shape of the portion of the leveling member facing the outer peripheral surface of the light collecting member is viewed from the tangential direction of the light collecting member, which is orthogonal to the direction in which the light collecting member and the leveling member are lined up, the above. The fixing device according to any one of claims 1 to 4, which has a wavy shape having a period equal to or less than a set interval. A forming means for forming a developer image on a recording medium, and
The fixing device according to any one of claims 1 to 5, wherein the developer image on the recording medium formed by the forming means is fixed to the recording medium.
An image forming apparatus having.