JP2013171068A - Electrophotographic device and photoreceptor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic device and a photoreceptor unit capable of easily adjusting an inter-axial distance between a rotation axis of a photoreceptor and a rotation axis of a developer carrier.SOLUTION: A electrophotographic device 1 includes: a photoreceptor unit 30 for storing a rotated photoreceptor 13; and a developer unit 12 for storing a rotated developer carrier 121. While an inter-axial distance D between a rotation axis α1 of the photoreceptor 13 and a rotation axis α2 of the developer carrier 121 is kept, image forming is carried out. The photoreceptor unit 30 includes: inter-axial distance adjusting means 310 for adjusting the inter-axial distance D so as to position the developer carrier 121 at an adjustment position relatively displaced in a contacting/separating direction W to/from the photoreceptor 13; locking means 320 for locking the adjustment position in the contacting/separating direction W of the developer carrier 121 at a large number of places; and fixing means 330 for fixing the adjustment position adjusted by the inter-axial distance adjusting means 310.

Description

  The present invention relates to an electrophotographic apparatus such as a copying machine or a printer, and more particularly, to an electrophotographic apparatus and a photosensitive unit provided with a photosensitive unit containing a rotating photosensitive member and a developing unit containing a rotating developer carrier. Regarding body units.

  As an electrophotographic apparatus for forming an image by an electrophotographic system, a photosensitive unit containing a rotating photosensitive member (specifically, a photosensitive drum) and a rotating developer carrier (specifically a developing roller) And a developing unit for storing the image.

  In such an electrophotographic apparatus, in order to achieve high-quality image formation, image formation is performed in a state in which the distance between the rotation axes of the photosensitive member and the rotation axis of the developer carrying member is maintained. For example, in the conventional configuration, a disk-shaped disk that is arranged coaxially with the developer carrier at both ends in the rotation axis direction of the developer carrier and is slightly larger in diameter than the outer diameter of the developer carrier. An abutting member (for example, a member called a DSD (Drum Sleeve Distance) collar or a spacer roller) is brought into contact with the surface of the photosensitive member, and the distance between the rotational axis of the photosensitive member and the rotational axis of the developer carrying member. The distance (specifically, the distance between the developer carrying member and the photosensitive member when developing in a state where the developer carrying member and the photosensitive member are not in contact with each other) is kept constant.

  However, in the configuration using the abutting member in this way, vibration generated during driving during the developing operation is easily transmitted to the photoconductor via the abutting member, and the development is performed when the vibration is transmitted to the photoconductor. Image defects such as unevenness are likely to occur in the image.

  On the other hand, there has been proposed an electrophotographic apparatus that maintains a constant distance between axes without using an abutting member.

  For example, in Patent Document 1, the other end of the unit main body of the photosensitive unit having the photosensitive drum is connected to the other end of the developing device main body of the developing device having the developing roller. Position adjustment coupling that adjusts the position of the photosensitive drum and the developing roller (that is, the distance between the axis of rotation of the photosensitive member and the axis of rotation of the developer carrying member) An electrophotographic apparatus comprising means is disclosed.

JP-A-10-2222042

  However, in the configuration as described in Patent Document 1, the distance between the axis of rotation of the photosensitive member and the axis of rotation of the developer carrying member is adjusted to a predetermined appropriate adjustment value (reference axis distance). In order to maintain this adjustment value, the adjustment position between the photosensitive member and the developer carrying member needs to be fixed, but when the adjustment position between the photosensitive member and the developer carrying member is fixed, the adjustment is performed. If the adjusted position is easy to move, the adjusted position of the photoconductor and developer carrier will be released, the adjustment will be repeated and the adjustment will be repeated. It was complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic apparatus and a photoreceptor unit that can easily adjust the distance between the axis of rotation of the photoreceptor and the axis of rotation of the developer carrier.

  In order to solve the above problems, the present invention provides the following electrophotographic apparatus and photoreceptor unit.

(1) Electrophotographic apparatus A photoconductor unit containing a rotating photoconductor and a developing unit containing a rotating developer carrier, and a rotation axis of the photoconductor and a rotation axis of the developer carrier An electrophotographic apparatus that forms an image while maintaining a distance between axes between the developer carrying member and the developer carrying member relatively displaced in the contact / separation direction with respect to the photoreceptor. An inter-axis distance adjusting means for adjusting the distance between the axes so as to be positioned at an adjustment position; a locking means for locking the adjustment position in the contact / separation direction of the developer carrying member at a plurality of locations; An electrophotographic apparatus comprising: fixing means for fixing the adjustment position adjusted by the distance adjusting means.

(2) Photoreceptor unit A photoreceptor unit that accommodates a rotating photoreceptor and a developing unit that accommodates a rotated developer carrier, the rotation axis of the photoreceptor and the rotation axis of the developer carrier The photosensitive unit is provided in an electrophotographic apparatus that forms an image while maintaining a distance between axes between the developer carrying member and the developer carrying member relative to the photosensitive member in the contact / separation direction. A distance adjusting means for adjusting the distance between the axes so as to be positioned at the adjusted position, a locking means for locking the adjustment positions in the contact / separation direction of the developer carrier at a plurality of locations, and the axis And a fixing unit that fixes the adjustment position adjusted by the distance adjustment unit.

  According to the present invention, the developer carrier in the contact / separation direction is adjusted by the locking means while adjusting the distance between the rotation axes of the photosensitive member and the rotation axis of the developer carrier. The adjustment position can be locked at a number of locations. Accordingly, when the adjustment position adjusted by the inter-axis distance adjusting means is fixed, the adjustment position can be made difficult to move, and accordingly, the rotation axis of the photosensitive member and the rotation axis of the developer carrying member can be reduced. It is possible to easily adjust the distance between the axes.

  In the present invention, the inter-axis distance adjusting means includes an eccentric cam in which a rotation axis is displaced with respect to a rotation axis of the developer carrier, and the eccentric cam is provided to position the developer carrier. A positioning portion, and the engaging means is provided on the eccentric cam, and an engaging portion provided with a number of concave and convex portions along a rotation direction around a rotation axis of the eccentric cam; and the concave and convex portion The aspect provided with the latching | locking part which has the latching claw which latches can be illustrated.

  In this specific matter, the concavo-convex portion in the engaging portion provided in the eccentric cam can be reliably locked by the locking claw in the locking portion.

  In the present invention, it is possible to exemplify an aspect in which the locking portion is cantilevered by the main body of the photosensitive unit and the locking claw is provided at a free end portion.

  In this specific matter, the locking claw is provided at the free end of the locking portion that is cantilevered by the main body of the photosensitive unit, so that the engagement portion provided in the eccentric cam has the The uneven portion can be more reliably locked.

  In the present invention, the inter-axis distance adjusting means includes an index indicating an adjustment amount of the inter-axis distance, and the index can be exemplified as being provided along the uneven portion in the engaging portion.

  In this specific matter, the index indicating the adjustment amount of the inter-axis distance is provided along the uneven portion of the engaging portion, so that the engagement of the eccentric cam is adjusted when the adjustment position is adjusted. An operator or the like can easily recognize how much to move from the current position with respect to the pawl.

  In the present invention, the fixing means includes a fixing member that fixes the adjustment position by being rotated in one direction in the rotation direction, and the uneven portion and the locking claw are provided on the eccentric cam. An example can be illustrated in which the rotation in one direction in the rotation direction is prohibited while the eccentric cam is allowed to rotate in the other direction in the rotation direction.

  In this specific matter, the concavo-convex portion and the locking claw prohibit the rotation of the eccentric cam in one direction in the rotation direction, while in the other direction in the rotation direction of the eccentric cam. Therefore, even if the adjustment position is fixed by rotating the fixing member in one direction in the rotation direction, the adjustment position is set to one side in the rotation direction. This makes it difficult to shift the distance between the axes from a predetermined distance between the reference axes.

  In the present invention, the fixing means includes a fixing member that fixes the adjustment position by being rotated in one direction in the rotation direction, and the concave and convex portion and the locking claw include the eccentric cam. A first locking force, which is a locking force of the locking claw with respect to the concavo-convex portion when rotated in one direction in the rotation direction, rotates the eccentric cam in the other direction in the rotation direction. The aspect made into the structure used as the structure which becomes larger than the 2nd latching force which is the latching force with respect to the said uneven | corrugated | grooved part of the said latching claw in the case of having made it can be illustrated.

  In this specific matter, the uneven portion and the locking claw are configured such that the first locking force of the locking claw when the eccentric cam is rotated in one direction in the rotation direction is the eccentricity. Since the cam is configured to be larger than the second locking force of the locking claw when the cam is rotated in the direction of the other side in the rotation direction, the fixing member is on one side in the rotation direction. By rotating in the direction, even if the adjustment position is fixed, it is difficult to shift the adjustment position in one direction in the rotation direction, thereby changing the distance between the axes from a predetermined distance between the reference axes. Can be difficult.

  In the present invention, the fixing member is typically rotated in one direction in the rotation direction, thereby tightening the eccentric cam with respect to the main body of the photosensitive unit and setting the adjustment position. An embodiment having a fixing screw for fixing can be exemplified.

  In this specific matter, the fixing member can be realized by a simple and inexpensive member called a screw.

  In this invention, the said uneven | corrugated | grooved part in the said engaging part can illustrate the aspect made into the shape of a sawtooth. In this case, the said uneven | corrugated | grooved part can be made into the specific aspect of following (a) and (b).

  That is, the uneven portion of the aspect (a) is configured such that, of the two sides constituting each of the serrated uneven portions, the side of the engaging portion that is in contact with the engaging claw is the eccentric cam. It is the aspect made into the shape parallel to the radial direction centering on this rotating shaft line.

  In this aspect (a), the side of the engagement portion of the serrated concave-convex portion of the engagement portion that is in contact with the engagement claw of the engagement portion is in the radial direction about the rotation axis of the eccentric cam By making the shape parallel to the above, the concave and convex portions can be reliably locked with a simple configuration by the locking claws.

  Moreover, the said uneven | corrugated | grooved part of aspect (b) is a side of the contact | abutting side with the said latching claw in the said latching | locking part among the two sides which comprise each said sawtooth-shaped uneven | corrugated | grooved part in the said rotation direction. It is the aspect made into the shape inclined in the direction of one side.

  In this aspect (b), the side of the engagement portion of the serrated concave-convex portion of the engagement portion that is in contact with the engagement claw of the engagement portion is inclined in the direction of one side in the rotation direction. Thus, the concave and convex portions can be reliably locked with a simple configuration by the locking claws.

  In the above aspects (a) and (b), the locking claw in the locking portion has a side on the contact side of the engaging portion with the concavo-convex portion around the rotation axis of the eccentric cam. The shape may be parallel to the radial direction, or may be inclined to the other side in the rotation direction.

  In this specific matter, in the above aspects (a) and (b), the side of the locking claw in the locking portion that is in contact with the concavo-convex portion of the locking claw is the rotation axis of the eccentric cam. By making the shape parallel to the radial direction centered at, the concave and convex portions can be more reliably locked with a simple configuration by the locking claws. Further, in the above aspects (a) and (b), the side of the locking claw in the locking portion that is in contact with the concavo-convex portion in the engaging portion is inclined in one direction in the rotation direction. By making it the shape which carried out, the said uneven | corrugated | grooved part can be more reliably latched by a simple structure with the said latching claw.

  In this invention, the said latching means can illustrate the aspect further equipped with the holding part which moves the said latching claw in the direction which the said latching claw leaves | separates from the said engaging part.

  In this specific matter, the holding portion can easily release the locking state of the locking claw with the uneven portion.

  As described above, according to the present invention, it is possible to easily adjust the distance between the axes of the rotation axis of the photosensitive member and the rotation axis of the developer carrying member.

1 is a front view showing a schematic configuration of an electrophotographic apparatus according to an embodiment of the present invention. 2A and 2B are diagrams schematically illustrating a state in which the photosensitive unit and the developing unit are mounted on the main body of the electrophotographic apparatus, in which FIG. 1A is a schematic cross-sectional view thereof, and FIG. It is a schematic plan view which shows a part. It is the schematic rear view which looked at the photoconductor unit from the back side. FIG. 3 is a schematic side view showing an internal structure of a rear side (back side) portion of the photosensitive unit together with a developing roller in the developing unit. It is the schematic perspective view which looked at the eccentric cam part in the photoconductor unit from diagonally downward. It is a figure which shows schematic structure of an eccentric cam, Comprising: (a) is a figure which shows the front view, (b) is a figure which shows the back view, (c) is the side view. FIG. FIG. 4 is a schematic rear view for explaining a state in which the distance between the axis of the photosensitive drum and the axis of rotation of the developing roller is adjusted in the electrophotographic apparatus, where (a) shows the widest distance between the axes. (B) is a figure which shows the state in which the distance between axes was adjusted. It is a schematic plan view which shows the latching state with the uneven | corrugated | grooved part in the engaging part of the latching claw in a latching part, Comprising: (a) is a figure which shows the other example of embodiment shown to FIGS. (B) is a figure which shows another example, (c) is a figure which shows another example.

  Embodiments according to the present invention will be described below with reference to the drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

(Electrophotographic equipment)
First, a schematic configuration of an electrophotographic apparatus 1 according to an embodiment of the present invention will be described below with reference to FIG.

  FIG. 1 is a front view showing a schematic configuration of an electrophotographic apparatus 1 according to an embodiment of the present invention. An electrophotographic apparatus 1 shown in FIG. 1 records and forms an image of a document read by a document reading device (not shown) or an image indicated by image data received from outside on a recording sheet P such as paper in color or single color. An image forming unit 10 is provided.

  The image forming unit 10 includes an exposure device 11, developing units 12 to 12, photosensitive drums 13 to 13 that act as a photosensitive member, cleaner devices 14 to 14, and chargers 15 to 15, and transfer units 30 to 30. Intermediate transfer belt device 16 including intermediate transfer rollers 24 to 24 that act as a portion, fixing device 17, paper feed tray 18 that acts as a paper feed portion, paper discharge tray 19 that acts as a paper discharge portion, and sheet transport device 20 It has.

  The image data handled in the image forming unit 10 corresponds to a color image using each color of black (K), cyan (C), magenta (M), yellow (Y), or a single color (for example, black). This corresponds to the monochrome image used. Accordingly, four development units 12 to 12, four photoreceptor units 30 to 30, and intermediate transfer rollers 24 to 24 are provided to form four types of images corresponding to the respective colors.

  The photoconductive drums 13 to 13 are disposed at substantially the center in the vertical direction of the main body 1 a of the electrophotographic apparatus 1. The chargers 15 to 15 are charging means for uniformly charging the surfaces of the photosensitive drums 3 to 3 to a predetermined potential. Here, the exposure device 11 is a laser scanning unit including a laser diode and a reflection mirror, and exposes the charged surfaces of the photosensitive drums 3 to 3 according to image data, and the surface according to the image data. An electrostatic latent image is formed. The developing units 12 to 12 develop the electrostatic latent images formed on the photosensitive drums 13 to 13 with (K, C, M, Y) toner. The cleaners 14 to 14 remove and collect toner remaining on the surfaces of the photosensitive drums 13 to 13 after development and image transfer.

  The intermediate transfer belt device 16 disposed above the photosensitive drums 13 to 13 includes an intermediate transfer belt 21, an intermediate transfer belt driving roller 22, a driven roller 23, and an intermediate transfer belt cleaning in addition to the intermediate transfer rollers 24 to 24. A device 25 and a tension roller 26 are provided.

  The intermediate transfer belt drive roller 22, the driven roller 23, the intermediate transfer rollers 24 to 24, and the tension roller 26 stretch and support the intermediate transfer belt 21, and the intermediate transfer belt 21 is supported in a predetermined sheet conveyance direction (arrow C in the figure). Direction). The intermediate transfer rollers 24 to 24 are rotatably supported inside the intermediate transfer belt 21 and are pressed against the photosensitive drums 13 to 13 via the intermediate transfer belt 21. The intermediate transfer belt 21 is provided so as to be in contact with each of the photosensitive drums 13 to 13, and the toner image on the surface of each of the photosensitive drums 13 to 13 is sequentially transferred to the intermediate transfer belt 21 to transfer the color. A toner image (a toner image of each color) is formed. Transfer of the toner image from the photosensitive drums 13 to 13 to the intermediate transfer belt 21 is performed by intermediate transfer rollers 24 to 24 that are in pressure contact with the inner side (back surface) of the intermediate transfer belt 21. A high-voltage transfer bias (for example, a high voltage having a polarity (+) opposite to the toner charging polarity (-)) is applied to the intermediate transfer rollers 24 to 24 in order to transfer the toner image.

  The image forming unit 10 further includes a secondary transfer device 27 including a transfer roller 27a that functions as a transfer unit. The transfer roller 27 a is in contact with the outside of the intermediate transfer belt 21. As described above, the toner images on the surfaces of the photosensitive drums 13 to 13 are stacked on the intermediate transfer belt 21 to become a color toner image indicated by the image data. The stacked toner images of the respective colors are transported together with the intermediate transfer belt 21 and transferred onto the recording sheet P by the secondary transfer device 27. The intermediate transfer belt 21 and the transfer roller 27a of the secondary transfer device 27 are pressed against each other to form a transfer nip region. The transfer roller 27a of the secondary transfer device 27 has a voltage (for example, a polarity (+) opposite to the charging polarity (−) of the toner) for transferring the toner image of each color on the intermediate transfer belt 21 to the recording sheet P. )) Is applied.

  The intermediate transfer belt cleaning device 25 removes and collects residual toner on the intermediate transfer belt 21. The intermediate transfer belt cleaning device 25 is provided with, for example, a cleaning blade that contacts the intermediate transfer belt 21 as a cleaning member, and residual toner can be removed and collected by this cleaning blade.

  The paper feed tray 18 is a tray for storing the recording sheets P, and is provided below the image forming unit 10 in the main body 1 a of the electrophotographic apparatus 1. A paper discharge tray 19 provided on the upper side of the image forming unit 10 is a tray for placing printed recording sheets P face down.

  Further, the main body 1 a of the electrophotographic apparatus 1 is provided with a sheet conveying device 20 for sending the recording sheet P of the paper feed tray 18 to the paper discharge tray 19 via the secondary transfer device 27 and the fixing device 17. Yes. The sheet conveying device 20 has an S-shaped sheet conveying path S, and along the sheet conveying path S, a pickup roller 31, a pair of separation rollers 31a and 31b, a registration roller 32, a pre-registration roller 33, and a fixing device. 17 and a paper discharge roller 34 are disposed.

  The pickup roller 31 is a draw-in roller that is provided at the downstream end of the sheet feeding tray 18 in the sheet conveying direction and supplies the recording sheets P from the sheet feeding tray 18 one by one to the sheet conveying path S. One separation roller 31a passes the recording sheet P between the other separation roller 31b and conveys it to the sheet conveyance path S while separating the recording sheets one by one. In the stopped state, the registration roller 32 abuts the leading end of the recording sheet P that has been conveyed, aligns the leading end of the recording sheet P, and in the transfer nip region between the intermediate transfer belt 21 and the secondary transfer device 27. The recording sheet P is conveyed with good timing in synchronization with the toner image formed on the intermediate transfer belt 21 so that the toner image on the intermediate transfer belt 21 is transferred to the recording sheet P. The pre-registration roller 33 is a small roller for promoting and assisting the conveyance of the recording sheet P.

  The fixing device 17 is a belt fixing type fixing device, and a fixing belt 173 is wound around a plurality of rollers (here, a fixing roller 171 and a heating roller 172). The fixing belt 173 can transfer heat from the heating roller 172 to the fixing roller 171. In the fixing device 17, the pressure roller 174 is pressed against the fixing roller 171 via the fixing belt 173. The fixing belt 173 has a predetermined thickness (for example, 250 μm). In the fixing device 17, the recording sheet P on which an unfixed toner image is formed is received, and the recording sheet P is sandwiched between the fixing belt 173 and the pressure roller 174 and conveyed. The recording sheet P after fixing the toner images of the respective colors is discharged onto the paper discharge tray 19 by the paper discharge roller 34.

  In the electrophotographic apparatus 1 described above, the recording sheet P fed from the sheet feeding tray 18 is formed on the recording sheet P by the photosensitive drums 13 to 13 while being conveyed along the sheet conveying path S. The toner image conveyed to the transfer belt 21 is transferred by the secondary transfer device 27 and further fixed by the fixing device 17 to perform the printing process.

  Specifically, the photosensitive drums 13 to 13 are rotationally driven in one direction, and after the surfaces neutralized by a neutralizing device (not shown) are cleaned by the cleaner devices 14 to 14, they are uniformly distributed by the chargers 15 to 15. Charged. The exposure device 11 repeatedly scans the surfaces of the photosensitive drums 13 to 13 in the main scanning direction with laser light modulated based on the image data, and forms electrostatic latent images on the surfaces of the photosensitive drums 13 to 13. The developing units 12 to 12 supply toner to the surfaces of the photosensitive drums 13 to 13 to develop (develop) the electrostatic latent images, and form toner images on the surfaces of the photosensitive drums 13 to 13. The intermediate transfer belt device 16 transfers the toner image formed on the photosensitive drums 13 to 13 to the transfer belt 21. The secondary transfer device 27 transfers the toner image formed on the transfer belt 21 to the recording sheet P that passes between the transfer belt 21 and the transfer roller 27a. The fixing device 17 heats and pressurizes the recording sheet P on which the toner image is formed, and fixes the toner image on the recording sheet P to the recording sheet P. Thus, the electrophotographic apparatus 1 completes a series of printing operations.

  It is also possible to form a monochrome image using at least one of the four image forming stations and transfer the monochrome image to the intermediate transfer belt 21 of the intermediate transfer belt device 16. This monochrome image is also transferred from the intermediate transfer belt 21 to the recording sheet P and fixed on the recording sheet P, similarly to the color image.

(Photoreceptor unit and development unit)
Next, schematic configurations of the photoconductor units 30 to 30 and the developing units 12 to 12 will be described below with reference to FIG.

  Since the four photoconductor units 30 to 30 and the four developing units 12 to 12 have the same configuration, description will be made using one photoconductor unit 30 and the developing unit 12.

  FIG. 2 is a diagram schematically illustrating a state in which the photosensitive unit 30 and the developing unit 12 are mounted on the main body 1a of the electrophotographic apparatus 1. FIG. 2A shows a schematic cross-sectional view, and FIG. 2B shows a schematic plan view of a rear side (back side) portion. In FIG. 2B, some components are not shown for easy understanding of the internal configuration.

  As shown in FIG. 2, the photoconductor unit 30 houses a photoconductor drum 13 (an example of a photoconductor) that is rotationally driven, and is photosensitive by a photoconductor unit main body (specifically, the photoconductor unit main body frame 30a). The body drum 13 is supported so as to be rotatable around the rotation axis α1.

  The photoreceptor unit 30 is detachably attached to the main body 1a of the electrophotographic apparatus 1 in the insertion / removal direction X (here, the depth direction orthogonal to both the vertical direction Z and the horizontal direction Y viewed from the front). It has become.

  In the photoconductor unit 30, when mounted on the main body 1a of the electrophotographic apparatus 1, a driving mechanism (not shown) such as a gear on the main body 1a side is engaged with a gear provided on the photoconductor drum 13, and the main body 1a. The rotational driving force from the drive mechanism on the side is transmitted to the photosensitive drum 13 via the gear, and the photosensitive drum 13 is rotationally driven in a predetermined rotational direction E1.

  Specifically, the photoreceptor unit 30 is slidably supported along the insertion / removal direction X by a guide member 1b (see FIG. 2A) provided on the main body 1a of the electrophotographic apparatus 1. ing. The main body 1a of the electrophotographic apparatus 1 includes a pair of photoreceptor positioning portions 41 and 42 (see FIG. 2B) that are inserted into each other in the insertion / removal direction X. One photoreceptor positioning portion 41 is provided on both the rear side (rear side) and front side (front side) side plates of the main body 1a of the electrophotographic apparatus 1 (the front side is not shown and the rear side is the rear frame 1c). Here, it is a recess extending along the insertion / removal direction X (specifically, a recess in the positioning member 40 provided in the main body 1a). The other photoconductor positioning section 42 is provided on both the rear and front side plates of the photoconductor unit main body of the photoconductor unit 30 (the front side is not shown and the rear side is the photoconductor unit main body frame 30a). The protrusion extends along the insertion / removal direction X. As a result, the one photoconductor positioning unit 41 provided in the main body 1a of the electrophotographic apparatus 1 and the other photoconductor positioning unit 42 provided in the photoconductor unit main body are inserted into each other, thereby the photoconductor unit 30. Can be attached to the main body 1a of the electrophotographic apparatus 1 so as to be movable in the insertion / removal direction X and immovable in a direction orthogonal to the insertion / removal direction X.

  Specifically, one of the photoconductor positioning units 41 is one or a plurality of (here, two) photoconductor positioning units 41 and 41. One of the two photoconductor positioning portions 41 and 41 is arranged along the left-right direction Y at a reference position for positioning the photoconductor using the photoconductor drum 13 as a reference member in the main body 1a of the electrophotographic apparatus 1. The other photoconductor positioning unit 42 includes one or a plurality of (here, two) photoconductor positioning units 42 and 42. The other two photoconductor positioning portions 42 and 42 are arranged along the left-right direction Y in the photoconductor unit body of the photoconductor unit 30 corresponding to the two two photoconductor positioning portions 41 and 41. The tips of the other two photoconductor positioning portions 42, 42 have a taper and taper in a conical shape.

  The developing unit 12 accommodates a developing roller 121 (an example of a developer carrier) that is rotationally driven, and is developed by a developing unit main body (specifically, the developing unit main body frame 12a (see FIG. 2A)). 121 is rotatably supported around the rotation axis α2.

  The developing unit 12 is detachably mounted in the insertion / removal direction X with respect to the main body 1a of the electrophotographic apparatus 1 to which the photosensitive unit 30 is mounted.

  In the developing unit 12, a drive mechanism (not shown) such as a gear on the main body 1 a side is attached to the rotating shaft 121 a of the developing roller 121 in a state where the developing unit 12 is mounted on the main body 1 a of the electrophotographic apparatus 1 with the photosensitive unit 30 mounted. Rotating driving force from the driving mechanism on the main body 1a side is transmitted to the rotating shaft 121a of the developing roller 121 via the gear, and the developing roller 121 is rotated in a predetermined rotation direction ( The photosensitive drum 13 is rotationally driven in a rotational direction E2) opposite to the rotational direction E1. The developing roller 121 includes a rotating shaft 121a, a developing sleeve 121b that is supported by the rotating shaft 121a and rotates around the rotating axis α2 along with the rotation of the rotating shaft 121a, and a roller that rotatably supports the rotating shaft 121a around the rotating axis α2. And a support shaft 121c.

  Specifically, the developing unit 12 is slidably supported along the insertion / removal direction X by the guide member 1c (see FIG. 2A) adjacent to the photosensitive unit 30. The main body 1a of the electrophotographic apparatus 1 includes a pair of developing roller positioning portions 51 and 52 (see FIG. 2B) that are inserted into each other in the insertion / removal direction X. One developing roller positioning part (an example of a positioning part) 51 is a rear and front side of the photosensitive unit main body of the photosensitive unit 30 (the front side is not shown, and the rear side is an eccentric cam in an inter-axis distance adjusting mechanism 310 described later. 311), here a recess extending along the insertion / removal direction X. The other developing roller positioning portion 52 is provided on the rear side and the front side of the developing unit main body of the developing unit 12 (the front side is not shown, and the rear side is a roller support shaft 121c of the developing roller 121). The protrusion extends along the direction X. Thus, one developing roller positioning portion 51 provided on the photosensitive unit main body and the other developing roller positioning portion provided on the developing unit main body in a state where the photosensitive unit 30 is mounted on the main body 1a of the electrophotographic apparatus 1. 52 are inserted into each other so that the developing unit 12 can be attached to the photoreceptor unit 30 so as to be movable in the insertion / removal direction X and not movable in the direction perpendicular to the insertion / removal direction X.

  Specifically, the roller support shaft 121c protrudes outside through the developing unit main body frame 12a. Here, the developing roller positioning portion 51 has an eccentric cam 311 (specifically, on the back side and the front side), and a positioning center line β (see FIG. 2B) is on the rotational axis α3 of the eccentric cam 311. It is provided so as to be displaced. Here, the other developing roller positioning portion 52 is provided at the rear end of the developing roller 121 at the rear side of the roller support shaft 121c so that the positioning center line β coincides with the rotational axis α2 of the developing roller 121.

  The movement of the photoconductor unit 30 mounted on the main body 1a of the electrophotographic apparatus 1 and the developing unit 12 on the drawing side in the insertion / removal direction X is finally fixed by a fixing member (not shown).

  The electrophotographic apparatus 1 is configured to perform image formation while maintaining the inter-axis distance D (see FIG. 2A) between the rotation axis α1 of the photosensitive drum 13 and the rotation axis α2 of the developing roller 121. It is said that. Here, the developing method of the developing unit 12 is a non-contact developing method in which the surface 121f of the developing roller 121 is developed without contact with the surface 13f of the photosensitive drum 13. Therefore, the electrophotographic apparatus 1 maintains a gap d (for example, 0.5 mm to 0.6 mm) between the surface 13f of the photosensitive drum 13 and the surface 121f of the developing roller 121 (see FIG. 2A). In this state, image formation is performed.

(Axis distance adjustment mechanism)
Next, a schematic configuration of the inter-axis distance adjusting mechanism 310 will be described below with reference to FIGS.

  FIG. 3 is a schematic rear view of the photoconductor unit 30 viewed from the back side. FIG. 4 is a schematic side view showing the internal structure of the rear side (back side) portion of the photoconductor unit 30 together with the developing roller 121 in the developing unit 12. FIG. 5 is a schematic perspective view of the eccentric cam 311 portion of the photoreceptor unit 30 as viewed obliquely from below. 4 and 5, some components are not shown in order to make each component easy to see.

  FIG. 6 is a diagram showing a schematic configuration of the eccentric cam 311. FIG. 6A shows a front view thereof. FIG. 6B shows a rear view thereof. FIG. 6C shows a side view thereof.

  As shown in FIGS. 3 to 6, the photoconductor unit 30 includes an inter-axis distance adjusting mechanism 310 (an example of an inter-axis distance adjusting unit), a locking mechanism 320 (an example of a locking unit), and a fixing mechanism 330 ( An example of fixing means).

  The inter-axis distance adjustment mechanism 310 is in an adjustment position where the developing roller 121 (specifically, the entire developing unit 12 as a whole) is relatively displaced with respect to the photosensitive drum 13 in the contact / separation direction W (see FIGS. 3 and 5). It is set as the structure which adjusts the distance D between axes (refer FIG.2 and FIG.3) so that it may be located. Here, since the developing method of the developing unit 12 is a non-contact developing method, the inter-axis distance adjusting mechanism 310 has a gap d (between the surface 13f of the photosensitive drum 13 and the surface 121f of the developing roller 121. 2) is adjusted (finely adjusted).

  In the present embodiment, the inter-axis distance adjustment mechanism 310 includes an eccentric cam 311 and one developing roller positioning portion 51 (see FIG. 4). The eccentric cam 311 has a configuration in which the rotation axis α3 is displaced (eccentric) with respect to the rotation axis α2 of the developing roller 121. One developing roller positioning portion 51 is provided on the eccentric cam 311 and functions as a positioning portion for positioning the developing roller 121. The tip of one developing roller positioning part 51 has a taper and is tapered in a conical shape.

  Specifically, the eccentric cam 311 is a member in which the first columnar member 311a and the second columnar member 311b are connected to each other with the central axis line aligned (specifically, integrally formed) (FIGS. 4 to 6). The central axis of the first cylindrical member 311a and the second cylindrical member 311b coincides with the rotational axis α3 of the eccentric cam 311 and the rotational axis α2 of the developing roller 121 is relative to the central axis of the second cylindrical member 311b. It ’s out of place. The first cylindrical member 311a is formed with a locking groove K (specifically, a positive groove) for an operator or the like to rotate the eccentric cam 311 using a tool (specifically, a positive screwdriver). . The rotational axis α3 of the eccentric cam 311 is located at the center of the locking groove K (see FIGS. 3, 5 and 6A). The first cylindrical member 311a is supported by the photoconductor unit main body frame 30a so as to be rotatable around the rotation axis α2 of the developing roller 121.

  The eccentric cam 311 further includes a circular portion (specifically, a circular member 311c) provided on the first cylindrical member 311a. In the present embodiment, the first cylindrical member 311a and the circular member 311c are connected to each other (specifically, integrally formed), and the rotation axis α2 of the developing roller 121 coincides with the central axis of the circular member 311c. Yes. Thereby, even when the developing unit 12 is not mounted, the operator or the like can predict the movement of the developing roller 121 by the circular member 311c when adjusting the inter-axis distance D.

  In the present embodiment, the inter-axis distance adjusting mechanism 310 is an index M (an amount of movement of the developing roller in the contact / separation direction W with respect to the photosensitive drum 13) indicating the adjustment amount of the inter-axis distance D (in FIG. 5 and FIG. 5). 6 (a)).

  The index M is provided along a large number of concave and convex portions 321a to 321a in the engaging portion 321 described later, and has a plurality of (here, nine) scales. Specifically, the indices M are provided at equal intervals in the engaging portion 321, and a center scale Ma serving as a guide for adjustment is provided at the center position of the scale. Specifically, the index M is given for each predetermined number of the uneven portions 321a to 321a.

(Locking mechanism)
The locking mechanism 320 is configured to lock the adjustment positions (locking positions) in the contact / separation direction W of the developing roller 121 at a number of locations. Here, the distance (pitch) e (see FIG. 5) between the adjustment positions adjacent to each other at the multiple adjustment positions where the developing roller 121 is locked in the contact / separation direction W is the minimum adjusted by the inter-axis distance adjustment mechanism 310. The unit adjustment range. Therefore, as the distance e between the adjustment positions is smaller, the inter-axial distance D (here, the gap d) can be adjusted with higher accuracy.

  In the present embodiment, the locking mechanism 320 includes an engaging portion 321 and a locking portion 322. The engaging portion 321 is provided on the eccentric cam 311. Further, the engaging portion 321 is provided with a large number of concave and convex portions 321a to 321a along the rotation direction R (contact / separation direction W) around the rotation axis α3 of the eccentric cam 311. The locking portion 322 has a locking claw 322a (see FIGS. 3 and 5) that locks the uneven portions 321a to 321a in the engaging portion 321.

  The locking portion 322 is cantilevered by the main body of the photosensitive unit 30 (specifically, the photosensitive unit main body frame 30a), and the locking claw 322a has a free end portion (specifically, the leading end portion 322b). ).

  The locking mechanism 320 moves the locking claw 322a in a separation direction V (see FIG. 5), which is a direction in which the locking claw 322a in the locking portion 322 moves away from the uneven portions 321a to 321a in the engagement portion 321. A grip portion 323 to be gripped is further provided.

  Specifically, the concave and convex portions 321a to 321a in the engaging portion 321 and the locking claw 322a in the locking portion 322 prohibit the rotation of the eccentric cam 311 in one direction R1 while the eccentric cam 311 rotates. The cam is allowed to rotate in the direction of the other side in the rotation direction.

  In other words, the concavo-convex portions 321a to 321a and the locking claw 322a are obtained when the eccentric cam 311 is rotated (rotated clockwise here) in the direction R1 on one side in the rotation direction R (contact / separation direction W). The first locking force F1 (see FIG. 5) against the concave and convex portions 321a to 321a of the locking claw 322a rotates the eccentric cam 311 in the direction R2 on the other side in the rotation direction R (contact / separation direction W) (here, left The second locking force F2 is larger than the second locking force F2 with respect to the concave and convex portions 321a to 321a of the locking claw 322a when the rotation claw 322a is rotated.

  In this Embodiment, the uneven | corrugated | grooved part 321a-321a in the engaging part 321 is made into the shape of a sawtooth shape (triangular mountain shape). Moreover, the latching claw 322a in the latching | locking part 322 is made into the sharp shape.

  Specifically, the engaging portion 321 is a fan-like plate-like member having a main (kamage) portion 321b (see FIG. 5) as a rotation center, and the first columnar member 311a is formed on the front side (back side) of the main portion 321b. And the circular member 311c is provided with the second cylindrical member 311b on the back side (front side) of the main part 321b. The concavo-convex portions 321a to 321a are provided on the outer peripheral end surface opposite to the main portion 321b in the radial direction centered on the rotation center of the engaging portion 321. The concavo-convex portions 321a to 321a in the engaging portion 321 are the two sides (here, straight sides) H1 and H2 (see FIG. 5) constituting the individual serrated concavo-convex portions 321a to 321a in plan view. A side H <b> 1 on the side of contact of the locking portion 322 with the locking claw 322 a is parallel to the radial direction N (see FIG. 5) about the rotation axis α <b> 3 of the eccentric cam 311. The locking portion 322 is a plate-like member that tapers from the proximal end portion 322c to the distal end portion 322b. The sharp locking claw 322a in the locking portion 322 has a shape in which the side H3 on the side of contact with the concavo-convex portion 321a in the engaging portion 321 is parallel to the radial direction N about the rotation axis α3 of the eccentric cam 311. It is said that. The photosensitive unit main body frame 30a is provided with a protrusion 30b (see FIG. 5). The locking portion 322 has a base end portion 322c fixed by a fixing member SC (see FIG. 5) such as a screw, and is positioned by a positioning hole 322d (see FIG. 5) inserted through the protruding portion 30b. ing.

  Specifically, the grip portion 323 is provided at the tip of the locking portion 322. The gripping part 323 is thicker than the locking part 322. Here, the gripping portion 323 has a hexahedral shape. Thereby, an operator etc. can make it easy to hold | grip the holding part 323. FIG. Note that the grip portion 323 may be spherical. In addition, the grip portion 323 is provided on the distal end side with respect to the locking claw 322a. Thereby, the operator etc. can move the latching | locking part 322 to the separation direction V in the state from which the load was reduced so much. The locking portion 322 branches in the middle from the proximal end portion 322c to the gripping portion 323 at the distal end, and a locking claw 322a is formed at the distal end on the branch side. The eccentric cam 311 and the engaging portion 321 are made of a resin material. The engaging portion 321 and the eccentric cam 311 are integrally formed. The locking part 322 is formed of an elastic member. The locking part 322 and the grip part 323 are made of a resin material. The locking part 322 and the grip part 323 are integrally formed.

(Fixing mechanism)
The fixing mechanism 330 is configured to fix the adjustment position adjusted by the inter-axis distance adjustment mechanism 310. As a result, the inter-axial distance D (here, the gap d) between the photosensitive drum 13 and the developing roller 121 can be maintained by the fixing mechanism 330.

  In the present embodiment, the fixing mechanism 330 includes a fixing member 331 (see FIGS. 3 and 5). The fixing member 331 fixes the adjustment position adjusted by the inter-axis distance adjustment mechanism 310 by rotating in the direction R1 on one side in the rotation direction R (contact / separation direction W) (here, rotating clockwise). It is configured.

  The fixing member 331 is rotated in the direction R1 on one side in the rotation direction R (contact / separation direction W) (here, rotated clockwise), whereby the main body (specifically, the main body of the photosensitive unit 30). The fixing screw 331a (FIG. 3 and FIG. 3) fixes the adjusting position adjusted by the inter-axis distance adjusting mechanism 310 by tightening the engaging portion 321 provided on the eccentric cam 311 with respect to the photoconductor unit main body frame 30a. 5).

  Specifically, the fixing member 331 includes a through hole 331b (see FIG. 5) that is provided in the engaging portion 321 and passes through the fixing screw 331a, and a screw that is provided in the photoconductor unit main body frame 30a and is screwed with the fixing screw 331a. And a hole 30c (see FIG. 5).

  Specifically, the through hole 331b allows the developing roller 121 to move in the contact / separation direction W with respect to the photosensitive drum 13 by the inter-axis distance adjustment mechanism 310, and the rotation direction R of the eccentric cam 311 It is a long hole extending along the (contact / separation direction W). That is, the length of the through-hole 331b that is a long hole is an adjustment width of the developing roller 121 that moves in the contact / separation direction W. Further, the center of the screw hole 30c screwed with the fixed screw 331a (the rotation center of the fixed screw 331a) is between the rotation axis α1 of the photosensitive drum 13 and the eccentric cam 311 between the photosensitive drum 13 and the eccentric cam 311. Is located on a virtual straight line γ (see FIG. 3) passing through the rotation axis α3.

  FIG. 7 is a schematic rear view for explaining a state in which the inter-axis distance D between the rotation axis α1 of the photosensitive drum 13 and the rotation axis α2 of the developing roller 121 is adjusted in the electrophotographic apparatus 1. FIG. 7A shows a state where the distance D between the axes is the largest, and FIG. 7B shows a state where the distance D between the axes is adjusted.

  In the electrophotographic apparatus 1 described above, the inter-axis distance D (here, the gap d) is adjusted in a state where the photoconductor unit 30 is mounted on the main body 1 and the developing unit 12 is not mounted on the main body 1. In performing such adjustment, first, an operator or the like makes the fixing screw 331 a of the fixing member 331 in the fixing mechanism 330 loose. Next, an operator or the like grasps the grip portion 323 and separates the engaging claw 322a from the concave and convex portions 321a to 321a in the separation direction V, while rotating the engagement portion 321 and the eccentric cam 311 in the rotation direction R (contact / separation). In the direction R1 on one side in the direction W), the central scale Ma is sufficiently rotated (in this case, rotated clockwise) so that the center scale Ma exceeds the locking claw 322a (for example, the distance D between the axes becomes the largest) (FIG. 7). (See (a)). Next, the operator or the like releases the gripping portion 323 to bring the locking claw 322 a into contact with the concave and convex portions 321 a to 321 a, and the tip of the tool (specifically, a Phillips screwdriver) in the locking groove K of the eccentric cam 311. The eccentric cam 311 is rotated by one rotation of the concave and convex portions 321a to 321a in the direction R2 on the other side in the rotation direction R (contact / separation direction W) (here, rotated counterclockwise). At this time, a measuring jig (not shown) for measuring the displacement of the second cylindrical member 311b (see FIGS. 4, 6B and 6C) of the eccentric cam 311 with respect to the photosensitive drum 13 is used. Then, the displacement of the cylindrical member 311b is measured. The measurement jig calculates a value of the inter-axis distance D corresponding to the measured displacement of the cylindrical member 311b, and displays the calculated value of the inter-axis distance D on a display screen (not shown) such as a display. The operator or the like observes the value of the inter-axis distance D displayed on the display screen of the measuring jig, and a predetermined reference inter-axis distance (for example, 0.5 mm) determined in advance based on the value of the inter-axis distance D. The eccentric cam 311 is rotated (in this case, counterclockwise). Specifically, when one scale of the index M is set to a value corresponding to 0.1 mm of the inter-axis distance D, measurement is performed when the locking claw 322a is located at the position of the scale “Q1” (see FIG. 7). When the value of the distance D between the axes displayed on the display screen of the jig is 1.2 mm, in order to set the value of the distance D between the axes to 0.5 as the distance between the reference axes, an operator or the like The locking claw 322a may be positioned at the position of the seventh scale “Q2” from the position of the scale “Q1” (see FIG. 7B). In addition, when the operator or the like has rotated the engaging portion 321 and the eccentric cam 311 too much (in this case, rotating counterclockwise), the operator grips the grip portion 323 and sets the locking claw 322a to the uneven portions 321a to 321a. The engagement portion 321 and the eccentric cam 311 are returned to desired positions while being separated from each other in the separation direction V (here, rotated clockwise), and the same adjustment operation is performed again.

  As described above, according to the present embodiment, the adjustment position of the developing roller 121 is locked (temporarily held) in the contact / separation direction W by the locking mechanism 320 while adjusting the distance D between the axes. Can do. Accordingly, when the adjustment position adjusted by the inter-axis distance adjustment mechanism 310 is fixed, the adjustment position can be made difficult to move, and accordingly, the rotation axis α1 of the photosensitive drum 13 and the rotation axis α2 of the developing roller 121 can be reduced. It is possible to easily adjust the distance D between the axes (here, the gap d).

  By the way, when the distance D between the axes is fixed at a predetermined distance between the reference axes, the distance D between the axes changes from a predetermined distance between the predetermined reference axes due to the transmission of vibration from the drive system, etc. Or the distance D between the axes changes from a predetermined distance between the reference axes due to an impact received by the photoreceptor unit 30 or the development unit 12 when the photoreceptor unit 30 or the development unit 12 is attached / detached or transported / carried. This causes inconvenience.

In this respect, in the present embodiment, the developing roller 121 is locked at a large number of locations in the contact / separation direction W by the locking mechanism 320, so that vibrations from the drive system can be transmitted, or the photosensitive unit 30 or The adjustment position fixed by the fixing mechanism 330 can be made difficult to shift even by an impact received by the photoconductor unit 30 or the developing unit 120 when the developing unit 12 is attached / detached or transported / transported. Also, it is possible to make it difficult to change the inter-axis distance D from the predetermined reference inter-axis distance. Therefore, even if it is used for a long period of time, it is possible to make it difficult to change the distance D between the axes once adjusted from the distance between the reference axes. The concavo-convex portions 321 a to 321 a in the engaging portion 321 provided in 311 can be reliably locked.

  In the present embodiment, the engaging claw 322a is provided at the free end of the engaging portion 322 that is cantilevered by the photoconductor unit main body frame 30a, so that the engaging portion provided in the eccentric cam 311 is provided. The concavo-convex portions 321a to 321a in 321 can be more reliably locked.

  In the present embodiment, the index M indicating the adjustment amount of the distance D between the axes (the amount of movement of the developing roller 121 in the contact / separation direction W with respect to the photosensitive drum 13) is indicated on the concave and convex portions 321a to 321a in the engaging portion 321. By being provided along, the operator can easily recognize how much the eccentric cam 311 should be moved from the current position with respect to the locking claw 322a when adjusting the adjustment position. .

  By the way, the position of adjustment by the inter-axis distance adjusting mechanism 310 is fixed by rotating the eccentric cam 311 and the engaging portion 321 in one direction R1 in the rotation direction R (contact / separation direction W) by the fixing member 331. At this time, the adjustment position is likely to shift in one direction R1 in the rotation direction R (contact / separation direction W), and as a result, the axial distance D is likely to change from a predetermined reference axial distance. The concavo-convex portions 321a to 321a and the locking claws 322a prohibit rotation of the eccentric cam 311 in one direction R1 in the rotation direction R, while rotating the eccentric cam in the other direction in the rotation direction. It is set as the structure which accept | permits. In other words, the concavo-convex portions 321a to 321a and the locking claw 322a are locked when the eccentric cam 311 and the engaging portion 321 are rotated in the direction R1 on one side in the rotation direction R (contact / separation direction W). The second engagement of the locking claw 322a when the first locking force F1 of the claw 322a rotates the eccentric cam 311 and the engaging portion 321 in the direction R2 on the other side in the rotation direction R (contact / separation direction W). It is set as the structure which becomes larger than the stopping force F2. Accordingly, the fixing member 331 is rotated in one direction R1 in the rotation direction R (contact / separation direction W), so that even if the adjustment position is fixed, the adjustment position is one in the rotation direction R (contact / separation direction W). Therefore, it is possible to make it difficult for the distance D between the axes to change from the predetermined distance between the reference axes.

  In the present embodiment, the eccentric cam 311 is tightened with respect to the photoconductor unit main body frame 30a by rotating in the direction R1 on one side in the rotation direction R (contact / separation direction W) as the fixing member 331. Since the fixing screw 331a for fixing the adjustment position is used, the fixing member 331 can be realized by a simple and inexpensive member called a screw.

  In the present embodiment, in the serrated uneven portions 321 a to 321 a in the engaging portion 321, the side H 1 on the contact side of the locking portion 322 with the locking claw 322 a is centered on the rotation axis α 3 of the eccentric cam 311. Since the shape is parallel to the radial direction N (see FIG. 5), the concave and convex portions 321a to 321a can be reliably locked with a simple configuration by the locking claws 322a.

  In the present embodiment, the side H3 on the contact side of the engagement portion 321 of the sharp engagement claw 322a of the engagement portion 322 with the uneven portion 321a is centered on the rotation axis α3 of the eccentric cam 311. Since the shape is parallel to the radial direction N, the concave and convex portions 321a to 321a can be more reliably locked with a simple configuration by the locking claws 322a.

  Further, in the present embodiment, the free end portion of the locking portion 322 is elastically deformed in the separation direction V by the grip portion 323 gripped to move the locking claw 322a from the engagement portion 321 in the separation direction V. Thus, the locked state of the locking claws 322a with the concave and convex portions 321a to 321a can be easily released. Further, since the grip portion 323 is provided on the tip side of the locking claw 322a, the locked state of the locking claw 322a with the concave and convex portions 321a to 321a can be released more easily.

  The uneven portions 321a to 321a are such that, of the two sides H1 and H2 constituting the individual serrated uneven portions 321a to 321a, the side H1 in contact with the locking claw 322a is rotated by the eccentric cam 311. In the case where the shape is parallel to the radial direction N with the axis α3 as the center, the side H3 on the contact side of the engaging claw 322a with the concavo-convex portion 321a is centered on the rotation axis α3 of the eccentric cam 311. The shape may be inclined in the direction R1 with respect to the radial direction N (see FIG. 8A).

  The uneven portions 321a to 321a are such that, of the two sides H1 and H2 constituting the respective serrated uneven portions 321a to 321a, the side H1 in contact with the locking claw 322a is rotated by the eccentric cam 311. The shape may be inclined in the direction R1 on one side in the direction R (contact / separation direction W). In other words, the concavo-convex portions 321a to 321a may have a shape in which each side H1 is inclined in the direction R1 with respect to the radial direction N around the rotation axis α3 of the eccentric cam 311. In this case, the side H3 on the contact side of the engaging claw 322a with the concave and convex portion 321a may be inclined in the direction R2 on the other side in the rotation direction R (contact / separation direction W) of the eccentric cam 311. Good (see FIG. 8B). In other words, the side H <b> 3 on the contact side of the engaging claw 322 a with the concave and convex portion 321 a may have a shape inclined in the direction R <b> 1 with respect to the radial direction N. For example, the inclination angle of the side H1 and the inclination angle of the locking claw 322a may be the same angle. In addition, when the side H1 is inclined in the direction R1, the side H3 on the contact side of the locking claw 322a with the concavo-convex portion 321a is in a radial direction centering on the rotation axis α3 of the eccentric cam 311. You may be made into the parallel shape (refer FIG.8 (c)).

  Further, in the present embodiment, illustration and description of the inter-axis distance adjusting mechanism 310, the locking mechanism 320, and the fixing mechanism 330 are omitted, but the rear side (front side) of the photoreceptor unit 30 ( It is provided in the same manner as the back side.

  In the present embodiment, the inter-axis distance adjustment mechanism 310, the locking mechanism 320, and the fixing mechanism 330 are applied to the electrophotographic apparatus 1 of the non-contact development type, but between the photosensitive drum 13 and the developing roller 121. The adjustment of the inter-axis distance D is substantially the same in the contact development method in which the surface 121f of the developing roller 121 contacts and develops the surface 13f of the photosensitive drum 13, and the inter-axis distance adjustment mechanism 310 and the locking mechanism 320 are the same. The fixing mechanism 330 may be applied to a contact developing type electrophotographic apparatus.

  In this embodiment, the drum-shaped photosensitive drum 13 is used as the photosensitive member. However, an endless photosensitive belt wound around a plurality of rollers may be used. In this case, the rotation axis of the photosensitive belt can be the rotation axis of the roller closest to the developer carrier among the plurality of rollers.

  In this embodiment, the developing roller 121 is used as the developer carrying member. However, an endless developing belt wound around a plurality of rollers may be used. In this case, the rotation axis of the developing belt can be the rotation axis of the roller closest to the photoreceptor among the plurality of rollers.

DESCRIPTION OF SYMBOLS 1 Electrophotographic apparatus 12 Developing unit 13 Photosensitive drum (an example of a photosensitive member)
30 photoconductor unit 30a photoconductor unit main body frame (an example of the main body of the photoconductor unit)
51 One developing roller positioning part (an example of a positioning part)
52 Other Development Roller Positioning Unit 121 Development Roller (Example of Developer Carrier)
310 Axis distance adjustment mechanism (an example of an axis distance adjustment means)
311 Eccentric cam 320 Locking mechanism (an example of locking means)
321a Uneven portion 321 Engaging portion 322 Locking portion 322a Locking claw 323 Grip portion 330 Fixing mechanism (an example of fixing means)
331 Fixing member 331a Fixing screw d Clearance D Axial distance F1 First locking force F2 Second locking force H1 Side H2 forming uneven portion Side M forming uneven portion Index R Rotating direction W of eccentric cam Direction α1 Rotating axis α2 of photosensitive drum Rotating axis α3 of developing roller Rotating axis of eccentric cam

Claims (13)

A photosensitive unit that accommodates a rotating photosensitive member; and a developing unit that accommodates a rotating developer carrier; and an axis interval between the rotational axis of the photosensitive member and the rotational axis of the developer carrier. An electrophotographic apparatus that forms an image while maintaining a distance,
The photosensitive unit is:
An inter-axis distance adjusting means for adjusting the inter-axis distance so as to be positioned at an adjustment position where the developer carrying member is relatively displaced in the contact / separation direction with respect to the photosensitive member;
Locking means for locking the adjustment position in the contact / separation direction of the developer carrying member at a number of locations;
An electrophotographic apparatus comprising: fixing means for fixing the adjustment position adjusted by the inter-axis distance adjustment means. The electrophotographic apparatus according to claim 1,
The inter-axis distance adjusting means includes an eccentric cam in which a rotation axis is displaced with respect to a rotation axis of the developer carrying member, and a positioning unit that is provided on the eccentric cam and positions the developer carrying member. Prepared,
The locking means is provided on the eccentric cam and has an engaging portion provided with a plurality of concave and convex portions along a rotation direction around a rotation axis of the eccentric cam, and a locking for locking the concave and convex portions. An electrophotographic apparatus comprising a locking portion having a claw. The electrophotographic apparatus according to claim 2, wherein
2. The electrophotographic apparatus according to claim 1, wherein the locking portion is cantilevered by a main body of the photosensitive unit, and the locking claw is provided at a free end portion. An electrophotographic apparatus according to claim 2 or claim 3, wherein
The inter-axis distance adjusting means includes an index indicating an adjustment amount of the inter-axis distance,
The electrophotographic apparatus according to claim 1, wherein the index is provided along the uneven portion of the engaging portion. The electrophotographic apparatus according to any one of claims 2 to 4, wherein
The fixing means includes a fixing member that fixes the adjustment position by being rotated in one direction in the rotation direction,
The concavo-convex portion and the locking claw prohibit the rotation of the eccentric cam in one direction in the rotation direction, but allow the rotation of the eccentric cam in the other direction in the rotation direction. An electrophotographic apparatus characterized by being configured. The electrophotographic apparatus according to any one of claims 2 to 4, wherein
The fixing means includes a fixing member that fixes the adjustment position by being rotated in one direction in the rotation direction,
The concavo-convex portion and the locking claw have a first locking force that is a locking force of the locking claw with respect to the concavo-convex portion when the eccentric cam is rotated in one direction in the rotation direction. The eccentric cam is configured to be larger than a second locking force that is a locking force of the locking claw with respect to the uneven portion when the eccentric cam is rotated in the direction of the other side. A feature of an electrophotographic apparatus. The electrophotographic apparatus according to claim 5 or 6, wherein
The fixing member includes a fixing screw for fixing the adjustment position by tightening the eccentric cam with respect to a main body of the photoreceptor unit by being rotated in one direction in the rotation direction. A feature of an electrophotographic apparatus. The electrophotographic apparatus according to any one of claims 5 to 7,
The concavo-convex portion in the engaging portion has a sawtooth shape, and of the two sides constituting each of the serrated concavo-convex portions, the contact side of the locking portion with the locking claw The electrophotographic apparatus is characterized in that the side is formed in a shape parallel to a radial direction centering on a rotation axis of the eccentric cam. The electrophotographic apparatus according to any one of claims 5 to 7,
The concavo-convex portion in the engaging portion has a sawtooth shape, and of the two sides constituting each of the serrated concavo-convex portions, the contact side of the locking portion with the locking claw The electrophotographic apparatus is characterized in that the side is inclined in one direction in the rotation direction. The electrophotographic apparatus according to claim 8 or 9, wherein
The locking claw in the locking portion has a side in contact with the concave and convex portion in the engaging portion that is parallel to the radial direction about the rotation axis of the eccentric cam. A feature of an electrophotographic apparatus. The electrophotographic apparatus according to claim 8 or 9, wherein
The locking claw in the locking portion has a shape in which a side on the contact side of the engaging portion with the concavo-convex portion is inclined in the direction of the other side in the rotation direction. apparatus. The electrophotographic apparatus according to any one of claims 2 to 11, wherein
The electrophotographic apparatus according to claim 1, wherein the locking means further includes a gripping part that moves the locking claw in a direction in which the locking claw is separated from the engaging part. A photosensitive unit that accommodates a rotating photosensitive member; and a developing unit that accommodates a rotating developer carrier; and an axis interval between the rotational axis of the photosensitive member and the rotational axis of the developer carrier. The photoreceptor unit provided in an electrophotographic apparatus that forms an image while maintaining a distance,
An inter-axis distance adjusting means for adjusting the inter-axis distance so as to be positioned at an adjustment position where the developer carrying member is relatively displaced in the contact / separation direction with respect to the photosensitive member;
Locking means for locking the adjustment position in the contact / separation direction of the developer carrying member at a number of locations;
A photoconductor unit comprising: fixing means for fixing the adjustment position adjusted by the inter-axis distance adjustment means.

Images