JP2019159020A - Image holding body, image formation device - Google Patents

Abstract

To provide an image holding body capable of reducing a vibration width of an outer peripheral surface of a cylindrical body with a shank formed on a support member, as a shaft, compared with when an end side inner peripheral face and a step surface form a right angle.SOLUTION: An image holding body 36 comprises: a cylindrical cylinder body 50 whose both end parts are opened; a pair of support members 60 for closing an opening of the cylinder body 50 in a state in which, each of parts of the support members is inserted into one of both end parts of the cylinder body 50, and supporting the cylinder body 50; and a photosensitive layer 70 formed on an outer peripheral surface 56 of the cylinder body 50. Both end parts of the inner peripheral surface 52 on the cylinder body 50 comprise respectively, an end side inner peripheral surface 52B whose inner diameter is larger than that of an inside inner peripheral surface 52A on inside of the axial direction (center side). In addition, a step surface 52C is formed between the end side inner peripheral surface 52B and the inside inner peripheral surface 52A. An angle θ1 formed of the end side inner peripheral surface 52B and the step surface 52C in a cut surface which is cut in a plane passing an axial line in view from the axial direction of the cylinder body 50, is 100 degree or greater and 160 degree or smaller.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image carrier and an image forming apparatus.

  In Patent Document 1, in the process of manufacturing a support for an electrophotographic photosensitive member by cutting the outer peripheral surface of a raw tube, the holding is performed when the outer peripheral surface is cut using a holding jig that holds the raw tube at both ends. A technique is described in which both end portions of an element tube held by a jig are processed into a conical surface.

JP 2007-264379 A

  In order to manufacture the cylindrical body by cutting the outer peripheral surface of the raw tube, first, both ends of the inner peripheral surface of the raw tube are cut. Thus, when the outer peripheral surface of the raw tube is cut, an end-side inner peripheral surface that comes into contact with the holding jig that holds the raw tube is formed.

  As described above, the inner peripheral surface of the raw tube has an end inner peripheral surface with improved accuracy, an inner inner peripheral surface, and a step surface between the end inner peripheral surface and the inner inner peripheral surface. It is formed. And in the cut surface cut | disconnected by the surface which passes along an axis line seeing from the axial direction of a raw tube, the end side inner peripheral surface and the level | step difference surface have comprised the right angle.

  In addition, when a photosensitive layer is formed on the outer peripheral surface of a cut cylindrical body, the coating solution for forming the photosensitive layer may adhere to the step surface, and this coating solution may solidify on the step surface. . Furthermore, when the support member on which the shaft portion constituting the rotation axis of the cylindrical body is formed is inserted into both ends of the cylindrical body and attached to the cylindrical body, the support member interferes with the coating liquid solidified on the step surface. Thereby, the attitude of the support member with respect to the cylindrical body is inclined, and the deflection width of the outer peripheral surface of the cylindrical body with the shaft portion formed on the support member as an axis is deteriorated, compared with the case where the attitude of the support member is not inclined. Resulting in.

  An object of the present invention is to reduce the runout width of the outer peripheral surface of the cylindrical body with the shaft portion formed in the support member as an axis, as compared with the case where the end side inner peripheral surface and the step surface form a right angle. is there.

  An image holding body according to claim 1 of the present invention is cylindrical, and has end-side inner peripheral surfaces that are recessed at both ends as compared to a center-side inner inner peripheral surface, the end-side inner peripheral surface, and the A cylindrical body having a stepped surface formed between the inner side inner peripheral surface and a cut surface cut along a plane passing through the axis when viewed in the axial direction, at least one of the end side inner peripheral surface and the The cylindrical body having an angle with the step surface of 100 degrees or more and 160 degrees or less, a photosensitive layer formed on the outer peripheral surface of the cylindrical body, whose properties are changed by light irradiation, and the cylindrical body A pair of support members that are in contact with the end-side inner peripheral surfaces of both end portions to support the cylindrical body and are formed with shaft portions that constitute a rotation axis of the cylindrical body.

  The image carrier according to claim 2 of the present invention is the image carrier according to claim 1, wherein the length of the step surface in the radial direction of the cylindrical body is 0.7 [mm] or less. Features.

  An image carrier according to claim 3 of the present invention is the image carrier according to claim 1 or 2, wherein a concave curved surface is formed between the end-side inner peripheral surface and the step surface. It is characterized by being.

  An image carrier according to a fourth aspect of the present invention is the image carrier according to the third aspect, wherein another convex curved surface is formed between the curved surface and the inner peripheral surface. It is characterized by.

  An image holding body according to a fifth aspect of the present invention is the image holding body according to any one of the first to fourth aspects, wherein the inner side inner peripheral surface has an inner end in the axial direction of the cylindrical body. The peripheral surface portion is formed with an additional inner peripheral surface that is recessed as compared with the general portion of the inner inner peripheral surface, and the stepped surface includes the end inner peripheral surface and the additional inner peripheral surface. And the second step surface of the additional inner peripheral surface and the general portion of the middle inner peripheral surface.

  The image carrier according to claim 6 of the present invention is the image carrier according to claim 5, wherein the length of the first step surface in the radial direction of the cylindrical body is the second step surface in the radial direction. It is characterized in that it is shorter than the length of.

  An image forming apparatus according to a seventh aspect of the present invention is the image carrier according to any one of the first to sixth aspects, a developing device that develops the electrostatic latent image formed on the image carrier, It is characterized by providing.

  According to the image carrier of claim 1 of the present invention, the outer peripheral surface of the cylindrical body having the shaft portion formed on the support member as an axis, as compared with the case where the end inner peripheral surface and the step surface form a right angle. Can be reduced.

  According to the image carrier of claim 2 of the present invention, as compared with the case where the length of the step surface is longer than 0.7 [mm], the outer periphery of the cylindrical body having the shaft portion formed on the support member as an axis. The runout width of the surface can be reduced.

  According to the image carrier of the third aspect of the present invention, the linear end-side inner peripheral surface and the linear step surface are in contact with each other at the cut surface cut along the plane passing through the axis when viewed from the axial direction. Compared to the case, the runout width of the outer peripheral surface of the cylindrical body with the shaft portion formed in the support member as an axis can be reduced.

  According to the image carrier of claim 4 of the present invention, it is formed on the support member as compared with the case where the linear step surface is formed on the cut surface cut along the plane passing through the axis when viewed from the axial direction. The runout width of the outer peripheral surface of the cylindrical body with the shaft portion as an axis can be reduced.

  According to the image carrier of claim 5 of the present invention, the shaft portion formed on the support member is used as an axis as compared with the case where the step surface is composed of one surface (when not separated). The runout width of the outer peripheral surface of the cylindrical body can be reduced.

  According to the image carrier of claim 6 of the present invention, the shaft portion formed on the support member is pivoted compared to the case where the length of the first step surface is longer than the length of the second step surface. The runout width of the outer peripheral surface of the cylindrical body can be reduced.

  According to the image forming apparatus of the seventh aspect of the present invention, it is possible to suppress the deterioration of the quality of the output image as compared with the case where the inner peripheral surface of the cylindrical body and the step surface form a right angle.

It is sectional drawing which showed the image holding body which concerns on 1st Embodiment of this invention. It is the front view which showed the image holding body which concerns on 1st Embodiment of this invention. 1 is a schematic configuration diagram illustrating an image reading apparatus according to a first embodiment of the present invention. It is drawing which showed the evaluation result of the image carrier which concerns on 1st Embodiment of this invention with the table | surface. It is drawing which showed the jig | tool etc. which were used for evaluating the image carrier which concerns on 1st Embodiment of this invention. (A) (B) (C) It is the schematic diagram which showed the process of manufacturing the cylindrical body of the image holding body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is the schematic diagram which showed the process of manufacturing the cylindrical body of the image holding body which concerns on 1st Embodiment of this invention. (A), (B), and (C) are schematic views showing a process of forming a photosensitive layer on the cylindrical body of the image carrier according to the first embodiment of the present invention. (A) (B) (C) It is the schematic diagram which showed the process of wiping off the coating liquid adhering to the cylindrical body of the image holding body which concerns on 1st Embodiment of this invention. (A) (B) (C) It is the schematic diagram which showed the process of wiping off the coating liquid adhering to the cylindrical body of the image holding body which concerns on the comparison form with respect to 1st Embodiment of this invention. It is the expanded sectional view which showed the image holding body which concerns on 2nd Embodiment of this invention. It is an expanded sectional view showing the image carrier concerning a 3rd embodiment of the present invention.

<First Embodiment>
An example of an image carrier according to a first embodiment of the present invention and an image forming apparatus including the image carrier will be described with reference to FIGS. In the drawing, an arrow H indicates the vertical direction of the apparatus (vertical direction), an arrow W indicates the apparatus width direction (horizontal direction), and an arrow L indicates the depth direction of the apparatus (horizontal direction).

(Image forming device)
As shown in FIG. 3, in the image forming apparatus 10, a storage unit 14 that stores a sheet member P as a recording medium from the lower side in the vertical direction to the upper side, and a sheet member that is stored in the storage unit 14. A transport unit 16 that transports P and an image forming unit 20 that forms an image on the sheet member P transported from the storage unit 14 by the transport unit 16 are provided in this order.

[Container]
The accommodating portion 14 includes an accommodating member 26 that can be pulled out from the apparatus main body 10 </ b> A of the image forming apparatus 10 to the near side in the apparatus depth direction, and the sheet member P is stacked on the accommodating member 26. Further, the accommodating portion 14 is provided with a delivery roll 30 that sends the uppermost sheet member P stacked on the accommodating member 26 to a conveying path 28 that constitutes the conveying portion 16.

[Transport section]
The transport unit 16 includes a plurality of transport rolls 32 that transport the sheet member P along the transport path 28.

(Image forming part)
The image forming unit 20 includes four image forming units 18Y, 18M, 18C, and 18K of yellow (Y), magenta (M), cyan (C), and black (K). In the following description, Y, M, C, and K may be omitted when there is no need to distinguish between Y, M, C, and K.

  Further, the image forming unit 20 is provided with an exposure device 42 that irradiates the image holder 36 provided in the image forming unit 18 of each color with exposure light of each color. Each color image forming unit 18 includes the image carrier 36 described above and a charging roll 38 that charges the surface of the image carrier 36. Further, the image forming unit 20 is provided with a developing device 40 that develops the electrostatic latent image formed by exposing the surface of the image carrier 36 charged by the exposure device 42 described above and visualizes it as a toner image. Yes.

  The image forming unit 20 also has an endless transfer belt 22 to which toner images formed by the image forming units 18 of the respective colors are collectively transferred, and the toner image transferred to the transfer belt 22 on the sheet member P. A transfer roll 24 for transferring is provided. Further, the image forming unit 20 includes a fixing device 34 that heats and pressurizes the toner image on the sheet member P and fixes the toner image on the sheet member P.

(Operation of image forming apparatus)
In the image forming apparatus 10, an image is formed as follows.

  First, the charging rolls 38 for each color to which a voltage is applied come into contact with the surface of the image carrier 36 for each color and uniformly charge the surface of the image carrier 36 at a predetermined potential. Subsequently, based on data input from the outside, the exposure device 42 irradiates the surface of the charged image carrier 36 with exposure light to form an electrostatic latent image.

  Thereby, an electrostatic latent image corresponding to the image data is formed on the surface of each image carrier 36. Further, each color developing device 40 develops the electrostatic latent image and visualizes it as a toner image. Further, the toner image formed on the surface of the image holding member 36 for each color is transferred to the transfer belt 22.

  Therefore, the sheet member P sent out from the accommodating member 26 to the transport path 28 by the sending roll 30 is sent out to the transfer position T where the transfer belt 22 and the transfer roll 24 come into contact. At the transfer position T, the sheet member P is nipped and conveyed between the transfer belt 22 and the transfer roll 24, whereby the toner image on the surface of the transfer belt 22 is transferred to the sheet member P.

  The toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device 34. Then, the sheet member P on which the toner image is fixed is discharged to the outside of the apparatus main body 10A by the transport roll 32.

(Main part configuration)
Next, the image carrier 36 will be described.

  As shown in FIG. 1, the image holding body 36 has a cylindrical cylindrical body 50 having both ends opened, and a part of the image holding body 36 is inserted into both ends of the cylindrical body 50 to close the opening of the cylindrical body 50. And a pair of support members 60 that support the cylindrical body 50. Further, the image carrier 36 includes a photosensitive layer 70 that is formed on the outer peripheral surface 56 of the cylindrical body 50 and changes its properties when irradiated with light. The photosensitive layer 70 includes an undercoat layer (not shown), a charge generation layer, and a charge transport layer that are sequentially stacked from the cylindrical body 50 side.

-Support member 60-
The support member 60 is integrally formed using a resin material. The support member 60 includes an insertion portion 62 that is inserted into the cylindrical body 50, and the outer side in the axial direction of the image holding body 36 with respect to the insertion portion 62 (the side away from the axial center of the image holding body 36. , Hereinafter referred to as “axially outer side”). Further, the support member 60 includes a disk portion 66 that is axially outer with respect to the cylindrical portion 64, and a shaft portion 68 that forms an axis of rotation of the image carrier 36 on the axially outer side with respect to the disk portion 66. ing.

  The shaft portion 68 has an outer diameter smaller than that of the cylindrical body 50, and is rotatably supported by support plates 74 (see FIG. 2) disposed at both ends of the image holding body 36. Further, the disk portion 66 has an outer diameter larger than that of the cylindrical body 50.

  Further, the cylindrical portion 64 has an outer diameter smaller than that of the disk portion 66 and is similar to the outer diameter of the cylindrical body 50 in which the photosensitive layer 70 is formed on the outer peripheral surface 56. The column portion 64 is provided with a facing surface 64 </ b> A that faces the end surface 54 of the cylindrical body 50.

  The insertion portion 62 has an outer diameter smaller than that of the column portion 64, and the outer diameter is the same as the inner diameter of an end-side inner peripheral surface 52B described later of the cylindrical body 50. Further, in the insertion portion 62, the axially extending portion in the axial direction extends to the inner side in the axial direction of the image holding member 36 (the side closer to the axial center of the image holding member 36, hereinafter referred to as “axially inner side”). A projecting portion 62B projecting inward is formed. An inner side surface 62C facing the inner side in the axial direction is formed at the tip of the protruding portion 62B.

  In addition, a gear 72 is attached to the shaft portion 68 on the right side in the drawing, and a rotational force from a motor (not shown) is transmitted to the image carrier 36 via the gear 72.

-Cylinder 50-
The cylindrical body 50 is formed in a cylindrical shape using an aluminum alloy (JIS A6063). Further, as shown in FIG. 1, the cylindrical body 50 has end-side inner peripheral surfaces 52B which are recessed at both ends of the inner peripheral surface 52 as compared with the inner-side inner peripheral surface 52A in the axially inner side (center side). Is formed. In other words, in the cylindrical body 50, end side inner peripheral surfaces 52B having a larger inner diameter than the inner inner peripheral surface 52A in the axially inner side (center side) are formed at both ends of the inner peripheral surface 52. . Further, a step surface 52C is formed on the inner peripheral surface 52 of the cylindrical body 50 between the end-side inner peripheral surface 52B and the middle-side inner peripheral surface 52A.

  In this configuration, when the support member 60 is inserted into the end of the cylindrical body 50, the opposing surface 64 </ b> A of the support member 60 and the end surface 54 of the cylindrical body 50 come into contact with each other. The position of the support member 60 with respect to the cylindrical body 50 is determined. Furthermore, the outer peripheral surface 62A of the insertion portion 62 of the support member 60 and the end-side inner peripheral surface 52B of the cylindrical body 50 are in contact with each other, whereby the position of the support member 60 with respect to the cylindrical body 50 in the radial direction of the image holding body 36 is reached. Is decided. In this state, the step surface 52C of the cylindrical body 50 and the inner side surface 62C of the support member 60 are opposed to each other in the axial direction of the image holding body 36.

  In the first embodiment, as an example, the outer diameter of the cylindrical body 50 is set to 30 [mm], the length is set to 365 [mm], and the thickness of the portion where the inner side inner peripheral surface 52A is formed is (Hereinafter referred to as “general thickness”) is a constant value of 0.9 [mm] or more and 1.5 [mm] or less. The length of the step surface 52C in the radial direction of the cylindrical body 50 (hereinafter referred to as “end step”) is a constant value of 0.1 [mm] or more and 0.83 [mm] or less. In consideration of the residual liquid evaluation described later, the end step is preferably 0.7 mm or less.

  Furthermore, an angle formed by the end-side inner peripheral surface 52B and the step surface 52C (hereinafter referred to as “stepped portion angle”, θ1 in the figure) in a cut surface cut along a plane passing through the axis G1 when viewed from the axial direction of the cylindrical body 50, It is set to a constant value of 100 degrees or more and 160 degrees or less. Further, the gap (GA1 shown in FIG. 1) between the step surface 52C and the inner surface 62C of the support member 60 is set to 0 [mm] or more and 0.5 [mm] or less.

  Here, the step angle is set to 160 [deg.] Or less because when the step angle [theta] 1 is larger than 160 [deg.], The rigidity of the image carrier 36 is partially reduced, and the image carrier 36 is operated. This is because there is a possibility that minute deformation may occur on the outer peripheral surface 56 of the cylindrical body 50 when it is applied.

(Manufacturing method of the image carrier 36)
Next, a method for manufacturing the image carrier 36 will be described. First, a method for manufacturing the cylindrical body 50 will be described.

-Manufacture of cylindrical body 50-
First, a method for manufacturing the cylindrical body 50 will be described. In the case of manufacturing the cylindrical body 50, a solid body of an aluminum alloy (JIS A6063 alloy) is extruded by using an extrusion device, and the aluminum alloy extruded by the extrusion device is extracted by using a drawing device, whereby the base tube 90 (FIG. 7 (A)).

  Furthermore, both end portions of the raw tube 90 are subjected to inlay processing (boring cutting), so that the end-side inner peripheral surface 52B and the stepped surface 52C are formed at both end portions of the raw tube 90. Specifically, as shown in FIG. 6A, the raw tube 90 is rotated around the axis G <b> 1 of the raw tube 90. Further, using the cutting tool 610, the inner peripheral surface 90A of the blank 90 is started to be cut from the end. 6A and 6B, the inner peripheral surface 90A is cut by moving the cutting tool 610 inward in the axial direction, and the end-side inner peripheral surface 52B is formed at the end of the raw tube 90. To do. Further, as shown in FIGS. 6B and 6C, the inner peripheral surface 90A is cut by moving the cutting tool 610 to the axial line G1 side while moving the cutting tool 610 in the axial direction, and the step surface 52C. Is formed at the end of the base tube 90.

  By performing this step on both end portions of the raw tube 90, the end-side inner peripheral surface 52B and the stepped surface 52C are formed on both end portions of the raw tube 90. The end-side inner peripheral surface 52B and the stepped surface 52C are surfaces formed by rotating the raw tube 90 around the axis G1 of the raw tube 90 and cutting the inner peripheral surface 90A of the raw tube 90. Therefore, it is formed with high positional accuracy with respect to the axis G <b> 1 of the raw tube 90.

  Further, in a state where the holding jig (not shown) is in contact with the end-side inner peripheral surface 52B to hold the pipe 90, the outer circumference of the pipe 90 is rotated while rotating the pipe 90 around the axis G1 together with the holding jig. The surface 90B is cut from one end to the other end in the axial direction. Thereby, as shown in FIGS. 7B and 7C, the cylindrical body 50 is manufactured. In addition, in order to form the outer peripheral surface 56 of the cylindrical body 50 in the state which hold | maintained the raw tube 90 in the state which made the holding jig contact the end side inner peripheral surface 52B formed with high position accuracy with respect to the axis line G1, it is cylindrical. The outer peripheral surface 56 of the body 50 is formed with high positional accuracy with respect to the axis G1.

-Formation of photosensitive layer 70-
Next, a method for forming the photosensitive layer 70 on the outer peripheral surface 56 of the cylindrical body 50 by a dip coating method will be described. 8 and 9 indicate the upward direction. When forming the photosensitive layer 70, as shown in FIG. 8A, the cylindrical body 50 is arranged to extend in the vertical direction above the immersion tank 640, and the inner peripheral surface of the upper end portion of the cylindrical body 50. The cylindrical body 50 is gripped from 52 using the gripping member 630. A rubber member 630A that is in close contact with the inner peripheral surface 52 of the cylindrical body 50 in the circumferential direction is attached to the distal end (lower end) of the gripping member 630.

  Further, by moving the gripping member 630 downward, as shown in FIG. 8B, the cylindrical body 50 is immersed in the undercoat layer forming coating liquid 642 (hereinafter “coating liquid 642”). Immerse in the bath 640. Thereby, the entire outer peripheral surface 56 of the cylindrical body 50 is immersed in the coating liquid 642 filled in the immersion tank 640. Here, the rubber member 630 </ b> A attached to the tip of the gripping member 630 is in close contact with the inner peripheral surface 52 of the cylindrical body 50 in the circumferential direction. For this reason, the inside of the cylindrical body 50 is sealed, and due to the liquid pressure of the coating liquid 642, the coating liquid 642 reaches the inside of the cylindrical body 50 from the lower end of the cylindrical body 50 until the stepped surface 52 </ b> C is immersed in the coating liquid 642. Infiltrate. In addition, since the coating liquid 642 does not enter the inside of the cylindrical body 50 from the upper end of the cylindrical body 50, the coating liquid 642 does not adhere to the step surface 52C on the upper end side of the cylindrical body 50.

  Further, by moving the gripping member 630 upward, the cylindrical body 50 is pulled up from the immersion tank 640 as shown in FIG. Accordingly, the entire outer peripheral surface 56 of the cylindrical body 50, the end surface 54 on the lower end side of the cylindrical body 50, the end side inner peripheral surface 52B on the lower end side of the cylindrical body 50, the step surface 52C on the lower end side of the cylindrical body 50, and the cylinder The coating liquid 642 adheres to the lower part of the inner peripheral surface 52A of the body 50.

  Next, the coating liquid 642 adhering to the end surface 54 on the lower end side of the cylindrical body 50, the end side inner peripheral surface 52B, and the step surface 52C is wiped off. When the coating liquid 642 is wiped off, as shown in FIG. 9A, the cylindrical body 50 is disposed so as to extend in the vertical direction above the wiping device 650, and the inner peripheral surface of the upper end portion of the cylindrical body 50. The cylindrical body 50 is gripped from 52 using the gripping member 630.

  The wiping device 650 includes a conical sponge material 652 whose upper end is cut off in the axial direction, a motor 654 that rotates the sponge material 652 around the axis, and a supply that supplies the wiping liquid to the sponge material 652. And a member (not shown).

  Then, the wiping liquid is supplied to the sponge material 652, and the gripping member 630 is moved downward toward the wiping device 650 while the sponge material 652 is rotated, as shown in FIG. 9B. Next, a part of the sponge material 652 is made to enter the lower end portion of the cylindrical body 50. Accordingly, the rotating sponge material 652 is pushed from above by the end surface 54 and the inner peripheral surface 52 of the cylindrical body 50, and deforms following the end surface 54 and the inner peripheral surface 52 of the cylindrical body 50. Then, the rotating sponge material 652 wipes the coating liquid 642 attached to the end surface 54 on the lower end side, the end side inner peripheral surface 52B, and the step surface 52C of the cylindrical body 50. In addition, about the rotation speed of the sponge material 652, it is set to 30 [rpm] as an example.

  Further, by moving the gripping member 630 upward, the cylindrical body 50 is pulled up from the wiping device 650 and separated from the sponge material 652 in the vertical direction, as shown in FIG. 9C. Thereafter, the coating liquid 642 attached to the outer peripheral surface 56 of the cylindrical body 50 is dried, so that an undercoat layer is formed on the outer peripheral surface 56 of the cylindrical body 50.

  The undercoat layer, the charge generation layer, and the charge transport layer are formed by changing the coating liquid for the charge generation layer overlaid on the undercoat layer and the charge transport layer overlaid on the charge generation layer. The photosensitive layer 70 is formed on the outer peripheral surface 56 of the cylindrical body 50.

-Mounting of the support member 60-
Next, the insertion portions 62 of the support member 60 are respectively inserted into both ends of the cylindrical body 50 in which the photosensitive layer 70 is formed on the outer peripheral surface 56, and the support members 60 are respectively attached to both ends of the cylindrical body 50. Thereby, the image carrier 36 is manufactured.

(Function)
Next, the operation of the image carrier 36 will be described together with the evaluation performed on the image carrier 36 or the cylindrical body 50.

〔Evaluation methods〕
-Residual liquid evaluation-
The photosensitive layer was formed on each specification cylinder by the method described above, and the coating solution remaining on the step surface 52C of the cylinder was evaluated. Regarding the evaluation, a case where the coating liquid is visually observed and the coating liquid does not adhere to the stepped surface 52C is set as “◯”, and the coating liquid adheres to the stepped surface 52C, but the stepped surface 52C can be seen through (the adhered coating). The case where the liquid was thin was designated as “Δ”. On the other hand, the case where the coating liquid adhered to the stepped surface 52C and the stepped surface could not be seen (when the deposited coating liquid was thick) was defined as “x”.

-Swing width evaluation-
With the method described above, the photosensitive layer was formed into a cylindrical body of each specification, and with the support members 60 attached to both ends of the cylindrical body, the runout width of the outer peripheral surface was evaluated for each specification. Specifically, as shown in FIG. 5, the shaft portion 68 of the support member 60 of the image carrier 36 is rotatably supported using a jig 660. Then, the deflection width of the outer peripheral surface 56 of the cylindrical body 50 on which the photosensitive layer 70 is formed is measured using a laser displacement meter. There are five measurement positions in total, which are positions at equal pitches in the axial direction including both ends of the cylindrical body 50 in the axial direction (see measurement position S1 in FIG. 5).

  At this measurement position S1, the image carrier 36 is rotated once, and the difference (position variation) between the minimum value and the maximum value is measured. Then, the maximum positional variation among the five measurement positions S1 is set as the shake width of the image holding member 36.

  When the shake width is 40 [μm] or less, the quality of the output image is not deteriorated due to the past results. Therefore, “○” is given, and the shake width is larger than 40 [μm] and 60 [μm]. In the following cases, the output image suffers from quality deterioration such as positional deviation from the past results, but “Δ” because it is an acceptable level in terms of merchantability. On the other hand, when the runout width is larger than 60 [μm], the output image has a quality deterioration such as a positional shift from the past results, and is “x” because it is an unacceptable level in terms of merchantability.

[Evaluation specifications]
1. As Example 1, an image holding body manufactured by a cylindrical body having a general thickness of 0.9 mm, an end step of 0.1 mm, and a step angle of 160 degrees was used (see FIG. 4).
2. As Example 2, an image holding body manufactured by a cylindrical body having a general thickness of 0.9 mm, an end step of 0.18 mm, and a step angle of 160 degrees was used.
3. As Example 3, an image holding body manufactured by a cylindrical body having a general thickness of 0.9 mm, an end step of 0.45 mm, and a step angle of 160 degrees was used.
4). As Example 4, an image holding body manufactured by a cylindrical body having a general thickness of 0.9 mm, an end step of 0.5 mm, and a step angle of 160 degrees was used.
5). As Example 5, an image holding body manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.1 mm, and a step angle of 160 degrees was used.
6). In Example 6, an image holding body manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.18 mm, and a step angle of 160 degrees was used.
7). In Example 7, an image carrier manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.7 mm, and a step angle of 160 degrees was used.
8). In Example 8, an image carrier manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.83 mm, and a step angle of 160 degrees was used.
9. As Example 9, an image holding body manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.1 mm, and a step angle of 100 degrees was used.
10. As Example 10, an image holding body manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.18 mm, and a step angle of 100 degrees was used.
11. As Example 11, an image carrier made of a cylindrical body having a general thickness of 1.5 mm, an end step of 0.7 mm, and a step angle of 100 degrees was used.
12 As Example 12, an image carrier manufactured by a cylindrical body having a general thickness of 1.5 [mm], an end step of 0.83 [mm], and a step angle of 100 [degree] was used.
13. As Comparative Example 1, an image holding body manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.1 mm, and a step angle of 99 degrees was used.
14 As Comparative Example 2, an image carrier manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.18 mm, and a step angle of 99 degrees was used.
15. As Comparative Example 3, an image carrier manufactured by a cylindrical body having a general thickness of 1.5 mm, an end step of 0.7 mm, and a step angle of 99 degrees was used.

〔Evaluation results〕
As for the evaluation results, as in the table shown in FIG. 4, for Examples 1 to 7 and 9 to 11, both the residual liquid evaluation and the swing width evaluation were “◯”. In Examples 8 and 12, both the residual liquid evaluation and the fluctuation width evaluation were “Δ”. On the other hand, in Comparative Examples 1 to 3, both the residual liquid evaluation and the swing width evaluation were “x”. In addition, about the value of the fluctuation width measured by each specification, it describes in the table | surface shown in FIG.

[Discussion]
The difference between Examples 1-12 and Comparative Examples 1-3 is the step angle of the cylindrical body. The step portion angles of Examples 1 to 12 are 100 degrees or more and 160 degrees or less, and the step portion angles of Comparative Examples 1 to 3 are 99 degrees. That is, it is less than 100 degrees.

  Moreover, the difference between Examples 1-7 and 9-11 and Examples 8 and 12 is an end step. The end step of Examples 1-7 and 9-11 is 0.1 [mm] or more and 0.7 [mm] or less, and the end step of Examples 8 and 12 is 0.83 [mm]. is there. That is, it is larger than 0.7 [mm].

-Consideration for residual liquid evaluation-
A process of forming the photosensitive layer 70 on the cylindrical body 50 will be considered. In this step, when the coating liquid adhering to the inner peripheral surface 52 of the lower end portion of the cylindrical body 50 is wiped off, the rotating sponge material 652 is pushed by the end surface 54 and the inner peripheral surface 52 of the cylindrical body 50. .

  Since the corner portion angles of Examples 1 to 12 are 100 degrees or more and 160 degrees or less, the sponge material 652 is formed on the inner peripheral surface 52 of the cylindrical body 50 as shown in FIG. The sponge material 652 contacts the corner formed by the end-side inner peripheral surface 52B and the step surface 52C. For this reason, it is thought that the residual liquid evaluation of Examples 1-12 became "(circle)" or "(triangle | delta)".

  Moreover, the edge part level | step difference of Examples 1-7 and 9-11 is 0.1 [mm] or more and 0.7 [mm] or less, and is small compared with the edge part level | step difference of Examples 8 and 12. For this reason, in Examples 1-7 and 9-11, compared with the edge part level | step difference of Example 8, 12, the area which a coating liquid adheres becomes small. For this reason, the residual liquid evaluation of Examples 1 to 7 and 9 to 11 is “◯”, and the residual liquid evaluation of Examples 8 and 12 is “Δ”.

  On the other hand, the step portion angle of Comparative Examples 1 to 3 is 99 degrees. That is, it is smaller than 100 degrees. For this reason, in the step of forming the photosensitive layer 70 on the cylindrical body 50, when the coating liquid adhering to the inner peripheral surface of the cylindrical body is wiped off, the rotating sponge material 652 is applied to the end surface and the inner peripheral surface of the cylindrical body. Even if pressed, it is considered that the corner formed by the end-side inner peripheral surface and the step surface does not contact. Specifically, as shown in FIG. 10B, the sponge material 652 does not deform along the inner peripheral surface of the cylindrical body, and there is a gap 656 between the sponge material 652 and the step surface (reference numeral 552C). Will occur. For this reason, the residual liquid evaluation of Comparative Examples 1 to 3 is considered to be “x”.

-Consideration for runout evaluation-
The residual liquid evaluation of Examples 1 to 7 and 9 to 11 was “◯”. Thereby, as shown in FIG. 1, the stepped surface 52 </ b> C of the cylindrical body 50 has no solid matter that is solidified by drying the coating liquid. Thus, the support member 60 is attached to the cylindrical body 50 without the inner surface 62C of the support member 60 interfering with the solid matter of the coating liquid. For this reason, about Examples 1-7, 9-11, when the support member 60 is attached to the cylindrical body 50 in the attitude | position as the aim of design, it thinks that deflection evaluation was set to "(circle)".

  Moreover, the residual liquid evaluation of Examples 8 and 12 was “Δ”. Thereby, there exists a thin solid substance which the coating liquid dried and hardened | cured in the level | step difference surface 52C. As a result, the inner surface 62 </ b> C of the support member 60 interferes with the thin solid coating liquid, and the support member 60 is attached to the cylindrical body 50. For this reason, in Examples 8 and 12, it is considered that the deflection evaluation is “Δ” because the support member 60 is attached to the cylindrical body 50 in a posture slightly inclined with respect to the design target.

  On the other hand, the residual liquid evaluation of Comparative Examples 1 to 3 was “x”. As a result, the end step 552C includes a thick solid that is solidified by drying the coating liquid. As a result, the inner surface 62C of the support member 60 interferes with the solid material of the thick coating liquid, and the support member 60 is attached to the cylindrical body 50. For this reason, in Comparative Examples 1 to 3, it is considered that the deflection evaluation is “x” because the support member 60 is attached to the cylindrical body 50 in a posture inclined with respect to the design target.

(Summary)
As described above, in the image carrier 36 of the first embodiment, the step portion angle of the cylindrical body 50 is not less than 100 degrees and not more than 160 degrees. For this reason, compared with the case where the step portion angle is less than 100 degrees (for example, when the step portion angle is orthogonal), the swing width of the outer peripheral surface 56 of the cylindrical body 50 is reduced. The step angle of the cylindrical body 50 is preferably 100 degrees or more and 150 degrees or less, more preferably 100 degrees or more and 130 degrees or less in consideration of partial rigidity reduction of the image carrier. preferable.

  In addition, by setting the end step of the cylindrical body 50 to 0.1 [mm] or more and 0.7 [mm] or less, the cylindrical body is more than the case where the end step is larger than 0.7 [mm]. The amount of the coating liquid remaining on the 50 step surfaces 52C is reduced. The end step of the cylindrical body 50 is preferably 0.1 [mm] or more and 0.7 [mm] or less, preferably 0.1 [mm] or more in consideration of reducing the amount of the remaining coating liquid. 0.4 [mm] or less is more preferable.

  Further, by setting the end step of the cylindrical body 50 to 0.1 [mm] or more and 0.7 [mm] or less, the amount of the coating liquid remaining on the step surface 52C of the cylindrical body 50 is reduced. Compared with the case where the step difference is larger than 0.7 [mm], the deflection width of the outer peripheral surface 56 of the cylindrical body 50 is reduced.

  Further, in the image forming apparatus 10, the deflection width of the outer peripheral surface 56 of the cylindrical body 50 is reduced, so that the image forming apparatus 10 includes an image holding body having a cylindrical body with a stepped portion angle of less than 100 degrees. Degradation of output image quality is suppressed.

Second Embodiment
Next, an example of an image carrier according to a second embodiment of the present invention and an image forming apparatus including the image carrier will be described with reference to FIG. Note that the image carrier and the image forming apparatus according to the second embodiment will be described mainly with respect to differences from the image carrier and the image forming apparatus according to the first embodiment.

  A concave curved surface 154 is formed between the end-side inner peripheral surface 152B and the stepped surface 152C of the cylindrical body 150 in the image carrier 136 according to the second embodiment, as shown in FIG. Further, a convex curved surface 158 is formed between the curved surface 154 and the inner inner peripheral surface 152A. In other words, the end-side inner peripheral surface 152B and the middle-side inner peripheral surface 152A are connected only by a curved surface. In the second embodiment, the step surface between the end-side inner peripheral surface 152B and the inner-side inner peripheral surface 152A is a surface formed by the concave curved surface 154 and the convex curved surface 158. . The curved surface 158 is an example of another curved surface. The step portion angle of the cylindrical body 150 is an angle formed by the end-side inner peripheral surface 152B and the step surface 152C.

  In addition, a convex curved surface 164 is formed between the outer peripheral surface 162A and the inner side surface 162C of the insertion portion 162 of the support member 160. The degree of curvature of the curved surface 164 of the support member 160 is large so as not to interfere with the curved surface 154 of the cylindrical body 150. For example, when the curved surface 164 and the curved surface 154 are formed with a constant radius, the radius of the curved surface 164 is larger than the radius of the curved surface 154. In addition, the radius described in this embodiment is a radius of 0.2 [mm] or more.

  Thus, the concave curved surface 154 is formed between the end side inner peripheral surface 152B and the step surface 152C. For this reason, a case where the straight end-side inner circumferential surface 152B and the linear stepped surface 152C are in contact with each other (in the case of a pin angle) on a cut surface cut along a plane passing through the axis G1 when viewed from the axial direction. In comparison, the sponge material 652 (see FIG. 9) that wipes the coating solution follows the inner peripheral surface 152 of the cylindrical body 150. For this reason, it is suppressed that the coating liquid remains on the inner peripheral surface 152, so that the runout width of the outer peripheral surface 156 of the cylindrical body 150 is reduced as compared with the case where the concave curved surface is not formed.

  In addition, since a convex curved surface 158 is formed between the curved surface 154 and the inner inner peripheral surface 152A, a straight surface is obtained by cutting along a plane passing through the axis as viewed in the axial direction. The number of surfaces constituting the inner peripheral surface 152 is reduced as compared with the case where the step surfaces are formed. For this reason, the sponge material 652 that wipes off the coating solution follows the inner peripheral surface 152 of the cylindrical body 150.

  Further, the sponge material 652 follows the inner peripheral surface 152 of the cylindrical body 150, so that the coating liquid is suppressed from remaining on the inner peripheral surface 152. In the cut surface cut along the axis passing through the axial direction, Compared with the case where a linear step surface is formed, the runout width of the outer peripheral surface 156 of the cylindrical body 150 is reduced.

  The operation of the other second embodiment is the same as that of the first embodiment.

<Third Embodiment>
Next, an example of an image carrier according to a third embodiment of the present invention and an image forming apparatus provided with the image carrier will be described with reference to FIG. Note that the image carrier and the image forming apparatus according to the third embodiment will be described mainly with respect to differences from the image carrier and the image forming apparatus according to the first embodiment.

  In the axial direction of the image carrier 236 according to the third embodiment, a portion of the inner side inner peripheral surface 252A of the cylindrical body 250 on the end side inner peripheral surface 252B side is compared with the general portion 258 of the inner side inner peripheral surface 252A. An additional inner peripheral surface 254 that is recessed is formed. The step surface 252C is between the first step surface 256A between the end inner peripheral surface 252B and the additional inner peripheral surface 254, and between the additional inner peripheral surface 254 and the general portion 258 of the inner inner peripheral surface 252A. It is divided into a second step surface 256B. The step portion angle of the cylindrical body 250 is an angle formed by the end-side inner peripheral surface 252B and the first step surface 256A.

  Further, the length (L1 in the drawing) of the first step surface 256A in the radial direction of the cylindrical body 250 is shorter than the length (L2 in the drawing) of the second step surface 256B in the radial direction.

  In this way, the step surface 252C is divided into the first step surface 256A and the second step surface 256B, so that the step surface is composed of one surface (when not divided), The length of the first step surface 256A in the radial direction of the cylindrical body 250 is shortened. For this reason, about 1st level | step difference surface 256A facing the inner surface 62C of the support member 60, the area which a coating liquid adheres becomes small. Furthermore, the amount of the coating liquid remaining on the first step surface 256A of the cylindrical body 250 is reduced by reducing the area to which the coating liquid adheres. Thereby, compared with the case where the level | step difference surface is comprised by one surface, the deflection width of the outer peripheral surface 256 of the cylindrical body 250 becomes small.

  The length of the first step surface 256A in the radial direction of the cylindrical body 250 is shorter than the length of the second step surface 256B. Therefore, compared to the case where the length of the first step surface 256A is longer than the length of the second step surface 256B, the area where the coating liquid adheres is smaller on the first step surface 256A. Furthermore, the amount of the coating liquid remaining on the first step surface 256A of the cylindrical body 250 is reduced by reducing the area to which the coating liquid adheres. Thereby, the runout width of the outer peripheral surface 256 of the cylindrical body 250 is smaller than the case where the length of the first step surface 256A is longer than the length of the second step surface 256B.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. This will be apparent to those skilled in the art. In the above embodiment, the step angle is defined so that the coating liquid does not adhere to the inner peripheral surfaces of both ends of the cylindrical bodies 50, 150, 250, but at least the step angle of one end to which the coating liquid adheres Etc. may be specified.

  In the above embodiment, the shaft portion 68 of the support member 60 is formed to protrude from the disk portion 66 in the apparatus depth direction, but the shaft portion may be formed in a concave shape (hole) in the disk portion 66.

  Further, although not specifically described in the above embodiment, the thickness of the tip of the protruding portion 62B of the support member 60 may be made thinner than the thickness of the base end. Thereby, when the tip of the protrusion 62B interferes with the solid matter of the coating liquid, the tip of the protrusion 62B is deformed, and the tilt of the support member 60 relative to the cylindrical body 50 is suppressed.

  Although not specifically described in the third embodiment, it is preferable to shorten the length of the end-side inner peripheral surface 252B in the axial direction as compared with the length of the additional inner peripheral surface 254 in the axial direction. This is preferable in view of partial rigidity reduction of the holding body.

  Although not specifically described in the third embodiment, the contact portion between the second step surface 256B and the general portion 258 is the same as that of the first embodiment in consideration of a partial rigidity reduction of the image carrier. Compared with the step surface 5252C and the inner side inner peripheral surface 52A, it is preferably on the outer side in the axial direction.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 36 Image holding body 40 Developing apparatus 50 Cylindrical body 52A Middle inner peripheral surface 52B End side inner peripheral surface 52C Step surface 56 Outer peripheral surface 60 Support member 68 Shaft portion 70 Photosensitive layer 136 Image holding member 150 Cylindrical body 152A Medium Side inner peripheral surface 152B End side inner peripheral surface 152C Stepped surface 154 Curved surface 156 Outer surface 158 Curved surface (an example of another curved surface)
160 Support member 236 Image holding body 250 Cylindrical body 252A Middle inner peripheral surface 252B End inner peripheral surface 252C Step surface 254 Additional inner peripheral surface 256 Outer peripheral surface 256A First step surface 256B Second step surface 258 General part

Claims (7)

Cylindrical, and at both ends, there is an end inner peripheral surface that is recessed as compared with the central inner peripheral surface, and a step surface between the end inner peripheral surface and the inner inner peripheral surface. An angle formed between at least one of the end-side inner circumferential surface and the stepped surface in a cut surface that is formed by a plane that passes through the axis when viewed in the axial direction is 100 degrees or more and 160. [Degree] the cylindrical body,
A photosensitive layer formed on the outer peripheral surface of the cylindrical body, the property of which is changed by light irradiation;
A pair of support members in contact with the end-side inner peripheral surfaces of both end portions of the cylindrical body to support the cylindrical body, and a shaft portion forming a rotation axis of the cylindrical body;
An image carrier comprising:   The image carrier according to claim 1, wherein a length of the step surface in a radial direction of the cylindrical body is 0.7 [mm] or less.   The image carrier according to claim 1, wherein a concave curved surface is formed between the end-side inner peripheral surface and the step surface.   The image carrier according to claim 3, wherein another curved surface having a convex shape is formed between the curved surface and the inner inner peripheral surface. In the axial direction of the cylindrical body, an additional inner peripheral surface that is recessed as compared with a general portion of the inner inner peripheral surface is formed in a portion of the inner inner peripheral surface on the end inner peripheral surface side. And
The step surface includes a first step surface between the end inner peripheral surface and the additional inner peripheral surface, and a second step between the additional inner peripheral surface and the general portion of the middle inner peripheral surface. The image carrier according to claim 1, which is divided into a surface and a surface.   The image carrier according to claim 5, wherein a length of the first step surface in the radial direction of the cylindrical body is shorter than a length of the second step surface in the radial direction. The image carrier according to any one of claims 1 to 6,
A developing device for developing the electrostatic latent image formed on the image carrier;
An image forming apparatus comprising: