JP2019074707A - Image forming apparatus, developing device, and regulation member - Google Patents

Abstract

To provide an image forming apparatus, a developing device, and a regulation member that can prevent a viscoelastic body from easily coming off, compared with the case where the image forming apparatus does not have movement prevention means that prevents movement of the viscoelastic body and does not have a contact part in contact with the viscoelastic body.SOLUTION: An image forming apparatus 10 comprises: a photoreceptor drum 34Y; a developing roll 220; a coil spring 94; and a tracking roll 300. The tracking roll 300 includes an outer ring member 310 that is in contact with the photoreceptor drum 34Y, an inner ring member 320 that is attached to the developing roll 220 and arranged inside the outer ring member 310, a viscoelastic body 330 that is attached while being held between the outer ring member 310 and inner ring member 320, and a movement prevention mechanism 400 that prevents movement of the viscoelastic body 330 in an axial direction of the developing roll 220.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus, a developing device, and a regulating member.

  In Patent Document 1, a first developer carrier for developing a toner image on an image carrier, a second developer carrier for developing a toner image on the image carrier, and the first developer carrier. A support member rotatably supporting the body, a swinging member rotatably supporting the second developer carrier around the first developer carrier, and the second developer carrier A developing device is described which comprises biasing means for biasing the body toward the image carrier, and buffer means capable of damping the vibration of the swinging member relative to the support member.

  Patent Document 2 discloses an image forming apparatus capable of printing an image on a recording sheet based on image data, and capable of carrying an electrostatic latent image formed based on the image data. An electrostatic latent image unit, a developing roller capable of supplying a developer to the electrostatic latent image carrier, and a developer accommodating container capable of supporting the developing roller and capable of accommodating the developer therein; A developer unit, biasing means for biasing the developing unit to bias the developing roller toward the electrostatic latent image carrier, and the developer container being disposed in contact with the developer container; There is disclosed an image forming apparatus including a vibration absorbing member capable of absorbing vibration of a storage container.

JP 2011-175157 A JP, 2011-13292, A

  A restricting member for restricting the distance between the image carrier and the developing roll, in which a visco-elastic body is provided between the outer ring member and the inner ring member, the visco-elastic body is provided between the outer ring member and the inner ring member There is a risk that

  The present invention can form an image that can make it difficult for the viscoelastic body to be detached as compared with the case where the movement preventing means for preventing the movement of the viscoelastic body is not provided or the case where the contact portion contacting the viscoelastic body is not provided. An object of the present invention is to provide an apparatus, a developing device and a regulating member.

The present invention according to claim 1 is
An image carrier for holding a latent image,
A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Movement preventing means for preventing movement of the visco-elastic body in the axial direction of the developing roll;
Image forming apparatus having

  According to a second aspect of the present invention, the movement preventing means is provided on at least one of the outer ring member and the inner ring member, and has a contact portion in contact with the visco-elastic body. It is.

The present invention according to claim 3 is
An image carrier for holding a latent image,
A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Have
In the image forming apparatus, at least one of the outer ring member and the inner ring member is provided with a contact portion that contacts the visco-elastic body in the axial direction of the developing roll.

  The present invention according to a fourth aspect is the image forming apparatus according to the second or third aspect, wherein the contact portion has at least one connecting portion for connecting the outer ring member and the inner ring member.

The present invention according to claim 5 is
Having a plurality of the connecting portions,
The image forming apparatus according to claim 4, wherein the plurality of connecting portions are arranged equiangularly with respect to an axis of the developing roller.

  According to a sixth aspect of the present invention, at least one of the connecting portions is disposed at the center of the outer ring member and the inner ring member in the axial direction of the developing roll. It is.

  In the invention according to claim 7, at least one of the connecting portions is disposed on the end side of the outer ring member and the inner ring member in the axial direction of the developing roll. Image forming apparatus.

  According to an eighth aspect of the present invention, the contact portion is a concave portion formed in at least one of the outer ring member and the inner ring member, and at least the convex portion formed in the visco-elastic body is fitted into. The image forming apparatus according to claim 2, further comprising a single recess.

The present invention according to claim 9 is
Having a plurality of the recesses,
9. The image forming apparatus according to claim 8, wherein the plurality of concave portions are arranged equiangularly with respect to an axis of the developing roll.

  According to a tenth aspect of the present invention, the contact portion is a convex portion formed on at least one of the outer ring member and the inner ring member, and the contact portion is fitted to a concave portion formed on the visco-elastic body 4. The image forming apparatus according to claim 2, further comprising at least one convex portion to be inserted.

The present invention according to claim 11 is
Having a plurality of the convex portions,
12. The image forming apparatus according to claim 11, wherein the plurality of convex portions are disposed equiangularly with respect to an axis of the developing roll.

  In the invention according to claim 12, the visco-elastic body is a material containing any one of polyimide, polyethylene terephthalate, polyoxymethylene resin, polyacetal resin, ether-based polyurethane, silicone, polon, special polyurethane and urethane rubber. The image forming apparatus according to any one of claims 1 to 11, wherein the image forming apparatus comprises:

The present invention according to claim 13 is
A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Movement preventing means for preventing movement of the visco-elastic body in the axial direction of the developing roll;
A developing device having

The present invention according to claim 14 is
A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Have
A developing unit in which at least one of the outer ring member and the inner ring member is provided with a contact portion which contacts the visco-elastic body in the axial direction of the developing roll.

The present invention according to claim 15 is
A restricting member for restricting the distance between an image carrier holding a latent image and a developing roll provided opposite to the image carrier and developing the latent image held by the image carrier,
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Movement preventing means for preventing movement of the visco-elastic body in the axial direction of the developing roll;
And the restriction member.

The present invention according to claim 16 is
A restricting member for restricting the distance between an image carrier holding a latent image and a developing roll provided opposite to the image carrier and developing the latent image held by the image carrier,
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Have
In at least one of the outer ring member and the inner ring member, a contact portion that contacts the visco-elastic body in the axial direction of the developing roll is provided.

  According to the first aspect of the present invention, it is possible to provide an image forming apparatus capable of making it difficult to remove the visco-elastic body as compared with the case where the visco-elastic body is not provided with the movement preventing means for preventing the movement. .

  According to the second aspect of the present invention, it is possible to provide an image forming apparatus capable of making it difficult to remove the visco-elastic body as compared with the case where the contact portion contacting the visco-elastic body is not provided.

  According to the third aspect of the present invention, it is possible to provide an image forming apparatus capable of making the visco-elastic body less likely to be detached as compared with the case where the contact portion contacting the visco-elastic body is not provided.

  According to the fourth aspect of the present invention, the structure of the restricting member can be simplified as the case where the contact portion and the connection portion are provided separately.

  According to the fifth aspect of the present invention, the fluctuation of the rotational speed of the regulating member can be suppressed as compared with the case where the plurality of connecting portions are not arranged equiangularly with respect to the center of the developing roller. .

  According to the sixth aspect of the present invention, the connecting portion can be embedded in the visco-elastic body, and the movement of the visco-elastic body in the axial direction of the developing roll can be prevented.

  According to the seventh aspect of the present invention, as compared with the case where the connecting portion is connected to the center of the inner ring member and the outer ring member in the axial direction of the developing roll, the space between the outer ring member and the inner ring member is injection molded. When injecting the melted visco-elastic material into space to form the visco-elastic body, the movement of the melted visco-elastic body can be made smooth.

  According to the eighth aspect of the present invention, it is possible to reduce the amount of material required to manufacture the restricting member as compared with the case where a connecting portion connecting the outer ring member and the inner ring member is used as the contact portion.

  According to the ninth aspect of the present invention, it is possible to make the visco-elastic body less likely to be detached as compared with the case where the recess is not disposed equiangularly to the center of the developing roller.

  According to the tenth aspect of the present invention, it is possible to reduce the amount of material required to manufacture the regulating member as compared with the case of using the connecting portion connecting the outer ring member and the inner ring member as the contact portion.

  According to the eleventh aspect of the present invention, it is possible to make the visco-elastic body less likely to be detached as compared with the case where the convex portions are not arranged equiangularly with respect to the center of the developing roller.

  According to the twelfth aspect of the present invention, the material of the viscoelastic body can be embodied.

  According to the thirteenth aspect of the present invention, it is possible to provide a developing device capable of making it difficult to remove the visco-elastic body as compared with the case where the visco-elastic body is not provided with the movement preventing means for preventing the movement.

  According to the fourteenth aspect of the present invention, it is possible to provide a developing device capable of making the visco-elastic body less likely to be detached as compared with the case where the contact portion contacting the visco-elastic body is not provided.

  According to the fifteenth aspect of the present invention, it is possible to provide a regulating member capable of making it difficult to remove the visco-elastic body as compared with the case where the visco-elastic body is not provided with the movement preventing means for preventing the movement.

  According to the sixteenth aspect of the present invention, it is possible to provide a regulating member capable of making it difficult for the visco-elastic body to be detached as compared with the case where the contact portion contacting the visco-elastic body is not provided.

FIG. 1 is a cross-sectional view showing an image forming apparatus according to an embodiment of the present invention from the front side. FIG. 2 is a cross-sectional view showing an image forming unit of the image forming apparatus from the front side. FIG. 2 is a cross-sectional view schematically showing the front portion of the image forming unit from the left side. FIG. 4A is a view showing an image forming unit in which the distance between the image carrier and the developing roll is minimized, and FIG. 4B is a diagram showing the image carrier and the image forming unit. FIG. 6 is a view showing an image forming unit in which the distance to the developing roll is maximized. FIG. 5A shows a first example of the tracking roll, FIG. 5A is a perspective view of the first example of the tracking roll, and FIG. 5B is a rear view of the first example of the tracking roll. The 2nd example of a tracking roll is shown, FIG. 6 (A) is a perspective view of the 2nd example of a tracking roll, FIG. 6 (B) is an outer ring member, an inner ring member and the 2nd example of a tracking roll. It is a perspective view which shows a connection part, FIG. 6 (C) is a perspective view which shows the visco-elastic body which the 2nd example of a tracking roll has. It is a perspective view which shows the 3rd example of a tracking roll. The 4th example of a tracking roll is shown, FIG. 8 (A) is a perspective view of the 4th example of a tracking roll, FIG. 8 (B) is an outer ring member and an inner ring member which a 4th example of a tracking roll has. It is a perspective view which shows and FIG. 8 (C) is a perspective view which shows the viscoelastic body which the 4th example of a tracking roll has. It is a rear view which shows the 5th example of a tracking roll.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the configuration of an image forming apparatus 10 according to an embodiment of the present invention. As shown in FIG. 1, the image forming apparatus 10 has an image forming apparatus main body 12. A sheet storage unit 14 is provided below the image forming apparatus main body 12, and a sheet discharge unit 16 is provided above the image forming apparatus main body 12. The sheet storage unit 14 stores a large number of sheets. A sheet conveyance path 18 is formed from the sheet storage unit 14 to the sheet discharge unit 16.

  The sheet placed at the top of the sheet storage unit 14 is fed out by the pickup roll 20. The fed sheet is temporarily stopped by the registration roll 24 to be subjected to positioning control, and conveyed toward a secondary transfer roll 40 described later at a predetermined timing.

  An image forming unit 22 is provided at the center of the image forming apparatus main body 12. The image forming unit 22 includes, for example, four image forming units 26Y, 26M, 26C, and 26K. The image forming units 26Y, 26M, 26C and 26K correspond to the respective colors of yellow (Y), magenta (M), cyan (C) and black (K), and are constant along the intermediate transfer belt 28. It is arranged at intervals. The intermediate transfer belt 28 is supported by, for example, two support rolls 30 and 32, and rotates in the arrow A direction.

  The image forming units 26Y, 26M, 26C, and 26K include photosensitive drums 34Y, 34M, 34C, and 34K, which are examples of image holding members, and developing devices 200Y, 200M, 200C, and 200K. The photosensitive drums 34Y, 34M, 34C, and 34K are opposed to the primary transfer rolls 38Y, 38M, 38C, and 38K with the intermediate transfer belt 28 interposed therebetween, and the image forming unit 26Y is formed by the primary transfer rolls 38Y, 38M, 38C, and 38K. , 26M, 26C, and 26K are primarily transferred to the intermediate transfer belt 28.

  The secondary transfer roll 40 opposes the support roll 32 with the intermediate transfer belt 28 interposed therebetween. The developer image that has been primarily transferred is secondarily transferred onto the sheet conveyed through the sheet conveyance path 18 by the secondary transfer roll 40.

  The sheet on which the developer has been secondarily transferred is conveyed to the fixing device 42. The fixing device 42 is a device for fixing the toner image transferred onto the sheet to the sheet using, for example, heat and pressure, and includes, for example, a heating roll 44 and a pressure roll 46. The sheet on which the developer image is fixed by the fixing device 42 is discharged to the sheet discharge unit 16 by the discharge roll 48.

  The image forming apparatus 10 further includes a reverse conveyance path 50. The reverse conveyance path 50 is a conveyance path for conveying the sheet on the upstream side of the resist roll 24 in the sheet conveyance path 18 while inverting the sheet on which the developer image is formed on one side. For example, two conveyance rolls 52 and 52 are disposed along the reverse conveyance path 50, and the sheet fed from the discharge roll 48 to the reverse conveyance path 50 is transferred to the sheet conveyance path 18 by the conveyance rolls 52 and 52. It is transported.

  In FIG. 2, an image forming unit 26Y for yellow, which is an example of the image forming unit 26, is shown. The configuration of the other image forming units 26M, 26C, and 26K is the same as that of the image forming unit 26Y for yellow, and thus the description thereof is omitted.

  The image forming unit 26Y applies light to the surface of the charging device 64Y for charging the photosensitive drum 34Y and the surface of the photosensitive drum 34Y charged by the charging device 64Y, in addition to the photosensitive drum 34Y and the developing device 200Y described above. Therefore, after the toner image is transferred to the intermediate transfer belt 28 by the latent image forming device 66Y for forming a latent image on the surface of the photosensitive drum 34Y and the primary transfer roll 38Y, the toner etc. remaining on the photosensitive drum 34Y And a cleaning device 68Y for removing and cleaning the photosensitive drum 34Y.

  The developing device 200Y is a two-component developing device that develops a latent image using a toner and a carrier. The developing device 200Y has a developing device side housing 202. The developing device side housing 202 is configured by joining an upper member 202a and a lower member 202b. Further, a developer circulation passage 204 is formed in the lower part of the developing device side housing 202. The developer circulation path 204 includes a first developer conveying member 206 and a second developer conveying member 208. Each of the first developer conveying member 206 and the second developer conveying member 208 includes a rotary shaft 210 and a spiral stirring and conveying portion 212 formed around the rotary shaft 210. Further, the first developer conveying member 206 and the second developer conveying member 208 are separated by a partition portion 214 formed in the central longitudinal direction. Openings (not shown) are formed on both sides of the partition 214 in the longitudinal direction. The developer circulates in the developer circulation path 204 through the opening.

  The developing device 200Y has a developing roll 220. The developing roller 220 is provided to face the photosensitive drum 34Y, and develops the latent image held by the photosensitive drum 34Y. A layer thickness regulating member 280 is provided on the upstream side of the developing area facing the photosensitive drum 34Y. The layer thickness regulating member 280 regulates the layer thickness of the magnetic brush formed on the developing roller 220. Then, the developer whose layer thickness is regulated by the layer thickness regulating member 280 is supplied to the developing region, and a toner image is formed on the photosensitive drum 34Y.

  FIG. 3 is a cross-sectional view schematically showing the front portion of the image forming unit 26Y from the left side. The image forming unit 26Y is symmetrical in the front and back direction (the left and right direction in FIG. 3 and the direction intersecting with the sheet in FIG. 1 and FIG. 2). The configuration on the rear side of the image forming unit 26Y is the configuration on the front side of the image forming unit 26Y. Since the description is the same as in FIG.

  As shown in FIG. 3, the photosensitive drum 34Y has a drum rotation shaft 36, and is rotatably supported by the photosensitive drum side housing 92 via the drum rotation shaft 36. Here, the photosensitive drum side housing 92 and the above-mentioned developing device side housing 202 (see also FIG. 2) can be made to approach each other, for example, by a configuration such as connecting with a hinge (not shown) or the like. It can be separated.

  The developing roller 220 described above has a cylindrical member 222 and a flange member 224 mounted on the front side of the cylindrical member 222, and the outer side (right end portion side) of the flange member 224 is used as a roll rotation shaft 226 The roll rotation shaft 226 is rotatably attached to the developing device side housing 202 via a bearing 228.

  The image forming unit 26Y further includes a coil spring 94. The coil spring 94 is an example of a biasing unit, one end of which is attached to the photosensitive drum side housing 92, and the other end of which is attached to the developing device side housing 202. Further, the coil spring 94 biases the developing device side housing 202 to the photosensitive drum 34Y side. That is, the coil spring 94 urges the photosensitive drum 34 and the developing roll 220 to approach each other.

  The image forming unit 26Y further includes a tracking roll 300. The tracking roll 300 is an example of a regulating member, and regulates the distance between the photosensitive drum 34Y and the developing roll 220. Further, the tracking roll 300 is provided coaxially with the developing roll 220 and mounted so as to be rotatable with respect to the roll rotation shaft 226.

  The tracking roll 300 has an outer ring member 310. The outer ring member 310 has a cylindrical shape, and the outer peripheral surface thereof is in contact with the photosensitive drum 34Y.

  The tracking roll 300 further includes an inner ring member 320. The inner ring member 320 is attached to the developing roll 220 and disposed inside the outer ring member 310. Also, the tracking roll 300 has a cylindrical shape and rotatably supports the roll rotation shaft 226 (the developing roll 220). More specifically, at least the inner peripheral surface of the inner ring member 320 is made of resin with low sliding resistance, and the inner peripheral surface is a sliding surface, and the inner peripheral surface rotatably supports the roll rotation shaft 226 doing.

  The tracking roll 300 further includes a visco-elastic body 330. The visco-elastic body 330 is mounted so as to be sandwiched between the outer ring member 310 and the inner ring member 320. As a specific material of the viscoelastic body 330, for example, thermoplastic elastomers such as styrene type, olefin type, polyvinyl chloride type, urethane type and amide type can be used, and polyimide, polyethylene terephthalate, polyoxymethylene resin, It can be composed of a material containing any one of polyacetal resin, ether-based polyurethane, silicone, poron, special polyurethane and urethane rubber.

  The outer ring member 310 and the inner ring member 320 are made of resin which is less likely to be elastically deformed as compared with the viscoelastic body 330. Further, the outer ring member 310, the inner ring member 320, and the visco-elastic body 330 can be integrally molded.

  In the tracking roll 300 configured as described above, when one of the outer ring member 310 and the inner ring member 320 is fixed and the other of the outer ring member 310 and the inner ring member 320 is moved, the visco-elastic body 330 becomes visco-elastic Thus, the positional relationship between the outer ring member 310 and the inner ring member 320 changes.

  In the tracking roll 300 configured as described above, for example, as the developing roll 220 moves or vibrates in the front-rear direction (the left-right direction in FIG. 3, the axial direction of the developing roll 220), The elastic body 330 may move in the front-rear direction with respect to the outer ring member 310 or the inner ring member 320, and the visco-elastic body 330 may be detached from the outer ring member 310 or the inner ring member 320. Therefore, in this embodiment, the tracking roll 300 has a movement prevention mechanism 400 (see, for example, FIG. 5) to prevent movement of the visco-elastic body 330 in the axial direction of the developing roll 220. The movement preventing mechanism 400 is an example of the movement preventing means. Details of the movement prevention mechanism 400 will be described later.

  The image forming unit 26Y further includes a tracking cap 250. The tracking cap 250 is an annular member, and has an outer diameter larger than that of the developing roller 220 and an outer diameter smaller than that of the tracking roller 300, and is mounted on the outer peripheral surface of the developing roller 220. It is desirable that the tracking cap 250 be rotatable relative to the developing roll 220.

  In the image forming unit 26Y configured as described above, the developing device side housing 202, the developing roll 220, the tracking roll 300, and the tracking cap 250 are urged toward the photosensitive drum 34Y integrally by the coil spring 94, The outer ring member 310 of the tracking roll 300 contacts the photosensitive drum 34Y. Then, at a position where the urging force of the coil spring 94 and the repulsive force of the viscoelastic body 330 due to the deformation of the viscoelastic body 330 are balanced, the developing device side housing 202, the developing roll 220, the tracking roll 300 and the tracking cap 250 is stationary.

  At this time, the viscoelastic body 330 is deformed in accordance with the distance between the photosensitive drum 34Y and the developing roller 220. More specifically, when the photosensitive drum 34Y and the developing roll 220 approach, the outer ring member 310 and the inner ring member 320 approach each other, and the viscoelastic body 330 is deformed so as to be crushed. Therefore, due to the deformation of the viscoelastic body 330, a change in the distance G (hereinafter referred to as DRS) between the developing roller 220 and the photosensitive drum 34Y is absorbed, and in this embodiment, the DRS fluctuates. Uneven development is suppressed.

  The operation of the image forming unit 26Y is described in FIG. 4, and the image forming unit 26Y in a state in which the DRS is minimized is illustrated in FIG. 4 (A), and is illustrated in FIG. 4 (B). , And the image forming unit 26Y in which the DRS is maximized.

  As shown in FIG. 4A, when the outer circumferential surface of the tracking cap 250 contacts the photosensitive drum 34Y, the developing roll 220 approaches the photosensitive drum 34Y further from this position even if the coil spring 94 is biased. It will not be possible. At this time, when the upper end portion of the inner ring member 320 in FIG. 4A moves toward the photosensitive drum 34Y, it is pushed by the inner ring member 320 and the outer ring member 310 so that the viscoelastic body 330 contracts. Is transformed into G1 in FIG. 4A indicates the minimum value of DRS.

  As described above, the developing roller 220, the tracking roller 300, the developing device side housing 202 and the like are biased by the coil spring 94 in a direction approaching the photosensitive drum 34Y. Therefore, as shown in FIG. 4B, the tracking roll 300 having an outer diameter larger than that of the tracking cap 250 is against the photosensitive drum 34Y even when the tracking cap 250 is separated from the photosensitive drum 34Y. As a result, the outer ring member 310 is pressed, and in this state, the DRS becomes maximum.

  FIG. 5 shows a first example of the tracking roll 300, and FIG. 5 (A) is a perspective view of the first example of the tracking roll 300, and FIG. 5 (B) shows the tracking roll 300. It is a rear view of the first example. In FIG. 5, for convenience of illustration, illustration of the viscoelastic body 330 of the tracking roll 300 is omitted.

  As shown in FIG. 5, the tracking roll 300 includes the above-described outer ring member 310 and the above-described inner ring member 320, and further includes a movement prevention mechanism 400. The movement prevention mechanism 400 is an example of the movement prevention means, and prevents movement of the visco-elastic body 330 in the direction of the axis of the developing roll 220 indicated by a line L, and has a contact portion 410. The contact portion 410 is provided on at least one of the outer ring member 310 and the inner ring member 320, and contacts the visco-elastic body 330 in the axial direction of the developer roll.

  The contact portion 410 has, for example, four connecting portions 412. The connecting portion 412 connects the inner ring member 320 and the outer ring member 310. In this first example, although the tracking roll 300 has four connecting portions 412, the tracking roll 300 may have at least one connecting portion 412.

  The four connecting portions 412 are disposed equiangularly with respect to the axis of the developing roll 220 indicated by a line L. More specifically, the four connecting portions 412 are arranged such that the angles formed by two adjacent connecting portions 412 with respect to the axis of the developing roller 220 are all 90 degrees.

  Further, in the first example, the connection portion 412 is disposed on the end side of the inner ring member 320 and the outer ring member 310 in the axial direction of the developing roll 220 indicated by a line L. More specifically, the connecting portion 412 is disposed on the front side (the far side in FIG. 5A) of the inner ring member 320 and the outer ring member 310 in the axial direction of the developing roll 220 indicated by a line L.

  In the first example of the tracking roll 300 configured as described above, for example, even if the visco-elastic body 330 tries to move in the axial direction of the developing roll 220 as the developing roll 220 vibrates, the visco-elastic body 330 interferes with the connecting portion 412, and axial movement of the developing roller 220 is prohibited.

  The connecting portion 412 is formed to be sufficiently thin, and is made of an elastic material such as resin, for example, and can be deformed. For this reason, the connection part 412 does not prevent the outer ring member 310 and the inner ring member 320 from approaching and moving away from each other, and does not prevent the deformation of the viscoelastic body 330.

  6 shows a second example of the tracking roll 300, and FIG. 6 (A) is a perspective view of the second example of the tracking roll 300, and FIG. 6 (B) shows the second example of the tracking roll 300. FIG. 6C is a perspective view showing a viscoelastic body 330 of a second example of the tracking roll 300. FIG. 6C is a perspective view showing an outer ring member 310, an inner ring member 320 and a connecting portion 412 of the second example.

  In the first example described above, the tracking roll 300 has the movement prevention mechanism 400, the movement prevention mechanism 400 has the contact portion 410, and the contact portion 410 has four coupling portions 412. On the other hand, in this second example, in the tracking roll 300, the tracking roll 300 has the movement prevention mechanism 400, the movement prevention mechanism 400 has the contact portion 410, and the connection portion 410 has eight connection portions. It has 412.

  Also in this second example. As in the first example described above, the connecting portion 412 is disposed so as to be equiangular to the axis of the developing roll 220. More specifically, in the second example, eight connecting portions 412 are formed so that two adjacent connecting portions 412 form an angle of 45 degrees with respect to the axis of the developing roller 220. Is arranged.

  In the first example described above, all the four connecting portions 412 are on the end side of the inner ring member 320 and the outer ring member 310 in the axial direction of the developing roller 220 (the thickness direction of the outer ring member 310 and the inner ring member 320). Was placed in On the other hand, in the second example, all the eight connecting portions 412 are disposed at the centers of the inner ring member 320 and the outer ring member 310 in the axial direction of the developing roll 220.

  In addition, although the visco-elastic body 330 is shown as a single-piece | unit in FIG.6 (C), this can remove the visco-elastic body 330 from the outer ring member 310, the inner ring member 320, and the connection part 412. Not shown. For example, in the case where the outer ring member 310, the inner ring member 320, the connecting portion 412, and the visco-elastic body 330 are simultaneously formed integrally using different materials, the visco-elastic body 330 is the outer ring member 310, the inner ring member 320. And the connection part 412 may not be able to be removed.

  FIG. 7 is a perspective view showing a third example of the tracking roll 300. As shown in FIG. In FIG. 5, for convenience of illustration, illustration of the viscoelastic body 330 of the tracking roll 300 is omitted.

  In the first example of the tracking roll 300 described above, in the axial direction of the developing roll 220 in which all four connecting portions 412 are indicated by the line L, the front side of the inner ring member 320 and the outer ring member 310 (FIG. 5A) It was placed in the back). On the other hand, in the third example, the connecting portions 412 b and 412 d which are two connecting portions 412 of the four connecting portions 412 are the inner ring in the axial direction of the developing roll 220 shown by the line L. The connection portions 412a and 412c which are disposed on the front side (the rear side in FIG. 7) of the member 320 and the outer ring member 310 and which are the other two connection portions 412 of the four connection portions 412 In the axial direction of the developing roller 220 shown in FIG. 1, the inner ring member 320 and the outer ring member 310 are disposed on the rear side (the front side in FIG. 7).

  A fourth example of the tracking roll 300 is shown in FIG. 8, and FIG. 8 (A) is a perspective view of the fourth example of the tracking roll 300, and FIG. 8 (B) is a view of the tracking roll 300. FIG. 6C is a perspective view showing a viscoelastic body 330 of the fourth example of the tracking roll 300. FIG. 6C is a perspective view showing the outer ring member 310 and the inner ring member 320 of the fourth example.

  In the first, second, and third examples described above, the tracking roll 300 has the movement prevention mechanism 400, the movement prevention mechanism 400 has the contact portion 410, and the contact portion 410 is connected. It had part 412. On the other hand, in the fourth example, the tracking roll 300 has the movement prevention mechanism 400, the movement prevention mechanism 400 has the contact portion 410, and eight contact portions 410 are formed on the outer ring member 310. The inner ring member 320 is formed with eight recessed portions 420.

  More specifically, in the outer ring member 310, four recesses 420 are formed on the rear side (front side in FIG. 8), and four recesses 420 are formed on the front side (rear side in FIG. 8). ing. Further, the eight concave portions 420 formed in the outer ring member 310 are arranged at equal angles with respect to the axis of the developing roller 220. More specifically, in the fourth example, the two adjacent concave portions 420 formed in the outer ring member 310 have an outer ring such that all the angles formed with respect to the axis of the developing roll 220 are 45 degrees. It is formed on the member 310.

  Further, in the inner ring member 320, four concave portions 420 are formed on the rear side (the front side in FIG. 8), and four concave portions 420 are formed on the front side (the rear side in FIG. 8). Further, the eight concave portions 420 formed in the inner ring member 320 are arranged at equal angles with respect to the axis of the developing roller 220. More specifically, in the fourth example, the two adjacent concave portions 420 formed in the inner ring member 320 have an outer ring such that all the angles formed with respect to the axis of the developing roll 220 are 45 degrees. It is formed on the member 310.

  The convex part 332 formed in the viscoelastic body 330 fits in the recessed part 420, respectively. The convex portions 332 are formed in the same number as the concave portions 420, and the respective convex portions 332 are formed at positions corresponding to the concave portions 420 to be fitted.

  In the fourth example, although the contact portion 410 has a plurality of recesses 420, the contact portion 410 may have at least one recess 420. In the fourth example, the recess 420 is formed in both the outer ring member 310 and the inner ring member 320, but the recess 420 may be formed in at least one of the outer ring member 310 and the inner ring member 320.

  A fifth example of the tracking roll 300 is shown in FIG. In the fourth example described above, the tracking roll 300 has the movement prevention mechanism 400, the movement prevention mechanism 400 has the contact portion 410, and the contact portion 410 has the recess 420. On the other hand, in the fifth example, the tracking roll 300 has the movement prevention mechanism 400, the movement prevention mechanism 400 has the contact portion 410, and eight contact portions 410 are formed on the outer ring member 310. It has the convex part 430 by which eight pieces are formed in the inner ring member 320.

  More specifically, in the outer ring member 310, four convex portions 430 are formed on the rear side (the front side in FIG. 9), and four convex portions 430 are on the front side (the rear side in FIG. 9). It is formed. Further, the eight convex portions 430 formed in the outer ring member 310 are arranged to be equiangular to the axis of the developing roll 220. More specifically, in the fourth example, two adjacent convex portions 430 formed on the outer ring member 310 have an angle of 45 degrees with respect to the axis of the developing roll 220. The outer ring member 310 is formed.

  The inner ring member 320 also has four projections 430 formed on the rear side (front side in FIG. 9) and four projections 430 on the front side (rear side in FIG. 8). . Further, the eight convex portions 430 formed on the inner ring member 320 are arranged at equal angles with respect to the axis of the developing roll 220. More specifically, in the fifth example, two adjacent convex portions 430 formed on the inner ring member 320 have an angle of 45 degrees with respect to the axis of the developing roll 220. The outer ring member 310 is formed.

  Recesses 334 formed in the visco-elastic body 330 fit into the protrusions 430, respectively. The concave portions 334 are formed in the same number as the convex portions 430, and the respective concave portions 334 are formed at positions corresponding to the convex portions 430 to be fitted.

  In the fifth example, although the contact portion 410 has a plurality of convex portions 430, the contact portion 410 may have at least one convex portion 430. Further, in the fifth example, although the convex portion 430 is formed on both the outer ring member 310 and the inner ring member 320, the convex portion 430 may be formed on at least one of the outer ring member 310 and the inner ring member 320. Good.

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 34 ... Photosensitive drum 94 ... Coil spring 200 ... Development device 220 ... Development roll 300 ... Tracking roll 310 ... Outer ring member 320 ... Inner ring member 330 ... Viscoelastic body 332 ... Convex part 334 ... Concave part 400 ... Movement prevention mechanism 410 ... Contact part 412 ... Coupling part 420 ... Concave part 430 ... Convex part

Claims (16)

An image carrier for holding a latent image,
A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Movement preventing means for preventing movement of the visco-elastic body in the axial direction of the developing roll;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the movement prevention unit is provided on at least one of the outer ring member and the inner ring member and has a contact portion that contacts the visco-elastic body. An image carrier for holding a latent image,
A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Have
An image forming apparatus, wherein at least one of the outer ring member and the inner ring member is provided with a contact portion that contacts the visco-elastic body in the axial direction of the developing roll.   The image forming apparatus according to claim 2, wherein the contact portion includes at least one connection portion connecting the outer ring member and the inner ring member. Having a plurality of the connecting portions,
The image forming apparatus according to claim 4, wherein the plurality of connecting portions are arranged equiangularly with respect to an axis of the developing roller.   The image forming apparatus according to claim 4, wherein at least one of the connecting portions is disposed at a center of the outer ring member and the inner ring member in an axial direction of the developing roller.   The image forming apparatus according to any one of claims 4 to 6, wherein at least one of the connecting portions is disposed on an end side of the outer ring member and the inner ring member in the axial direction of the developing roll.   The contact portion is a recess formed in at least one of the outer ring member and the inner ring member, and has at least one recess into which a protrusion formed in the visco-elastic body is fitted. Or the image forming apparatus according to 3. Having a plurality of the recesses,
The image forming apparatus according to claim 8, wherein the plurality of concave portions are arranged equiangularly with respect to an axis of the developing roll.   The contact portion is a convex portion formed on at least one of the outer ring member and the inner ring member, and has at least one convex portion fitted to a concave portion formed on the visco-elastic body An image forming apparatus according to claim 2 or 3. Having a plurality of the convex portions,
The image forming apparatus according to claim 11, wherein the plurality of convex portions are disposed equiangularly with respect to an axis of the developing roll.   The visco-elastic body is made of a material containing any one of polyimide, polyethylene terephthalate, polyoxymethylene resin, polyacetal resin, ether-based polyurethane, silicone, poron, special polyurethane and urethane rubber. 11. The image forming apparatus according to any one of the above. A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Movement preventing means for preventing movement of the visco-elastic body in the axial direction of the developing roll;
Developing device. A developing roll provided opposite to the image carrier and developing a latent image held by the image carrier;
Biasing means for biasing the image carrier and the developing roll to approach each other;
A restricting member that restricts the distance between the image carrier and the developing roll;
Have
The restriction member is
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Have
A developing unit in which at least one of the outer ring member and the inner ring member is provided with a contact portion which contacts the visco-elastic body in the axial direction of the developing roll. A restricting member for restricting the distance between an image carrier holding a latent image and a developing roll provided opposite to the image carrier and developing the latent image held by the image carrier,
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Movement preventing means for preventing movement of the visco-elastic body in the axial direction of the developing roll;
Said restricting member having. A restricting member for restricting the distance between an image carrier holding a latent image and a developing roll provided opposite to the image carrier and developing the latent image held by the image carrier,
An outer ring member contacting the image carrier;
An inner ring member attached to the developing roller and disposed inside the outer ring member;
A visco-elastic body mounted so as to be sandwiched between the outer ring member and the inner ring member;
Have
The restriction member, wherein at least one of the outer ring member and the inner ring member is provided with a contact portion that contacts the visco-elastic body in the axial direction of the developing roll.

Images