JP2006276096A - Photosensitive drum base body holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce shavings produced when a photosensitive drum base body and a holder holding it are rubbed against each other when the photosensitive drum base body is mounted in a process of manufacturing an electrophotographic photosensitive drum. <P>SOLUTION: The holder 10 includes a pedestal 14 and a support column 18 which is mounted on the pedestal 14 and held movably on its mount surface 16. The support column has three leg portions 28 which extend radially outward at its lower part, and the pedestal is provided with a holding ring 20 having holding portions 34 holding the leg portions with the pedestal. The holding ring has reception portions 36 formed by cutting the holding portion to receive the leg portions at three peripheral places. The support column is held on the pedestal by inserting the leg portions into the reception portions and then rotating the holding ring. A gap is formed between leg portion front edge surfaces 48 and a holding ring inner peripheral surface 50 to allow the support column to move. When the photosensitive drum base body 12 is mounted, the support column 18 moves to absorb misalignment if any, and shavings are reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a holder for holding a photosensitive drum substrate in the process of manufacturing a photosensitive drum for electrophotography.

  In general, as a method for producing an organic photosensitive drum, there is currently employed a method in which a coating liquid containing an organic photoconductive pigment is applied on a photosensitive drum substrate as a conductive support and then dried. This method has an advantage that continuous production is possible as compared to a vapor deposition method in which a photoconductive material such as Se is heated and evaporated in a vacuum and deposited on a substrate to produce a photosensitive drum. . In particular, in the method using the above-described coating solution, a dispersion of an organic pigment such as a phthalocyanine compound or an azo compound is applied on the undercoat layer formed on the photosensitive drum substrate, and this is dried to generate charges. Then, a binder solution containing a triarylamine compound, a benzidine compound, a stilbene compound, a hydrazone compound, a pyrazoline compound, etc. is applied thereon and dried to form a charge transport layer. The material-separated organic electrophotographic photosensitive continuous production method is widely practiced because it has advantages such as easy selection of materials and low production costs.

  In the above photosensitive continuous production method, a metal pallet such as stainless steel and a resin pallet, which are excellent in durability and the like, are used for transporting the photosensitive drum substrate. The pallet is provided with a support portion for supporting individual photosensitive drum bases in contact with the inner surface of the cylinder. However, there are various sizes of the photosensitive drum substrate, and it is necessary to use a pallet having support columns corresponding to the size for each production. For this reason, when production is changed to a photosensitive drum of a different size, there is a problem that it takes time to replace the pallet. Techniques for providing a mechanism for mechanically opening and closing the support portion for the various sizes are described in Patent Documents 1, 2, and 3 below. This method has a complicated operation mechanism and a high manufacturing cost.

  Further, Japanese Patent Application Laid-Open Publication No. 2004-228667 describes a technique for making a pallet separable into a support part and a pedestal and exchanging the support part in accordance with the produced photosensitive drum. Even in this method, the support portion may fall off due to vibration during conveyance. Further, since the support portion and the pedestal portion are separated, the support portion may be mounted with a shift from a predetermined position. In such a case, when the photosensitive drum base is mounted on the support portion, the inner periphery of the drum base may be mounted. There is a problem that the edge of the surface and the support portion are rubbed and metal shavings are generated. The shavings may be mixed in the coating liquid and remain on the surface of the photosensitive drum on which the shavings are applied. An image copied using such a photosensitive drum has a problem that white spots and black spots occur.

  Further, Japanese Patent Application Laid-Open Publication No. 2004-259542 describes a technique for absorbing the misalignment between the drum base and the support when the photosensitive drum base is inserted into the support. A separable support portion is supported by the main body via a spring, and horizontal movement is allowed by deformation of the spring. Even when the misalignment occurs, the spring is deformed and the support portion moves, and the misalignment is absorbed.

Japanese Patent Laid-Open No. 5-94027 JP 2000-24859 A JP 2000-25564 A JP-A-5-337779 JP-A-6-110260

  In the apparatus described in Patent Document 5 in which the supporting portion that supports the photosensitive drum base is supported by a spring so as to be movable in the horizontal direction and the misalignment is allowed, disassembly around the spring is complicated when cleaning is performed. Yes, workability is reduced. Further, there is a problem that deterioration of the spring or the like occurs due to continuous use, a malfunction of movement in the horizontal direction occurs, and the misalignment cannot be absorbed.

  An object of the present invention is to provide a holder for a photosensitive drum base having a structure that can absorb these misalignments when the photosensitive drum base is mounted on a support portion with a simple configuration.

  The photosensitive drum base holder of the present invention is mounted on a pedestal having a flat mounting surface and a mounting surface of the pedestal so that the axis of the photosensitive drum base is perpendicular to the mounting surface. The supporting column is supported, and the supporting column is held so as to allow a predetermined amount of movement on the mounting surface while maintaining the axis of the supporting column vertical, and a holding member fixed to the pedestal.

  Since the leg portion of the support column is held between the base and the holding portion of the holding member, the vertical movement of the support column is restricted, while the horizontal movement is allowed by a predetermined amount.

  The support column extends outward in the radial direction, contacts the mounting surface of the pedestal, and has a plurality of legs that support the support column, while the holding member has an annular shape, A holding part for holding the leg part between the base part and the base, and a receiving part for receiving the leg part of the support column. The support part is mounted on the pedestal by inserting the leg part of the support column from the receiving part of the holding member, rotating the support column to position the leg part facing the holding part of the holding member.

  The support column is mounted by a simple operation in which the leg portion is aligned with the receiving portion of the holding member, and the support column is rotated around the axis so that the leg portion enters between the pedestal and the holding portion of the holding member.

  The holding member further has a facing surface at a position facing the leg tip of the support column, and a gap is provided between the facing surface and the leg tip, and the movement of the support column is allowed by this gap. The This gap can be 0.5-2.5 mm, i.e. 1-5 mm in diameter.

  Furthermore, a part of the ball at the tip protrudes from the mounting surface on the pedestal, and the ball can be provided with a ball plunger biased by a spring from the back. When the support column is mounted, the leg part pushes down the ball against the urging force of the spring, gets over this, and reaches the holding part. The ball plunger prevents the support column from coming off.

  Furthermore, it is possible to subject the support column to a surface that contacts the pedestal, the holding portion of the holding member, or the photosensitive drum substrate. The friction coefficient can be reduced by the tuffram treatment, and the support column can be moved more smoothly in the horizontal direction.

  With a simple configuration, the support pillar can be allowed to move on the mounting surface of the pedestal, and the mutual misalignment when the photosensitive drum base is mounted on the support pillar can be absorbed by this movement.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a photosensitive drum substrate holder (hereinafter referred to as a holder) 10 according to the present embodiment, and shows a state in which a photosensitive drum substrate 12 is held. The holder 10 includes a pedestal 14, a support column 18 placed on a placement surface 16 that is an upper surface of the pedestal 14, and a holding ring 20 that holds the support column 18 on the pedestal 14. The photosensitive drum base 12 is placed on a lower arm portion 22 whose bottom surface is provided at a lower portion of the support column and directed radially outward. Further, the photosensitive drum base 12 is in contact with the front ends of the middle arm portion 24 and the upper arm portion 26 provided on the inner peripheral surface of the photosensitive drum base 12 at the center portion and the upper portion of the support pillars toward the radially outer side. In this way, the photosensitive drum base 12 is supported by the support pillar 18.

  A leg portion 28 is provided at the lowermost portion of the support column 18. As shown in FIG. 2, the leg portions 28 are provided at intervals of 120 degrees in the circumferential direction and extending outward in the radial direction, and the bottom surfaces thereof are in contact with the mounting surface 16 of the pedestal, so Is vertically erected on the base 14. The upper arm portion 26, the middle arm portion 24, and the lower arm portion 22 are also provided at intervals of 120 degrees in the circumferential direction like the leg portion 28. Further, the upper surfaces 32 and 30 of the upper arm portion 26 and the middle arm portion 24 are tapered so that the upper portions thereof are thinner.

  The holding ring 20 holds the leg portion 28 between the pedestal 14 and the support column 18 on the pedestal 14. FIG. 3 is a perspective view showing the holding ring 20. The retaining ring 20 has a substantially L-shaped cross section, and is fixed to the pedestal 14 by inverting the L shape. A portion corresponding to the L-shaped image in the horizontal direction extends toward the inside of the holding ring 20, and this portion serves as a holding portion 34 that holds the leg portion 28 of the support column between the base 14. The holding part 34 is not provided over the entire circumference, but there are portions where the holding part is not provided and is cut at intervals of 120 degrees in the circumferential direction. This portion is provided corresponding to the leg portion 28 of the support column, and can pass the leg portion 28 in the vertical direction. When the support column 18 is mounted, the leg portion 28 is received until it contacts the pedestal 14. be able to. Hereinafter, a portion where the holding portion 34 is not provided is referred to as a receiving portion 36. The relationship between the leg portion 28 of the support column 18 and the holding portion 34 and the receiving portion 36 of the holding ring 20 is well illustrated in FIG. FIG. 2 shows a state in which the leg portion 28 is held by the holding portion 34.

  FIG. 4 is a developed cross-sectional view in which the cross section taken along the line AA shown in FIG. 2 is developed. As shown in FIG. 4, the holding ring 20 is fixed to the pedestal 14 with bolts 38. More specifically, the retaining ring 20 is provided with bolt holes 40 at three locations at intervals of 120 degrees in the circumferential direction. The bolt 38 passes through the bolt hole 40 and reaches the pedestal 14. Further, the shaft portion of the bolt 38 that penetrates also functions as a stopper that stops the counterclockwise rotation of the leg portion 28 (in the case of FIG. 4, movement in the right direction) at this position. As shown in FIG. 4, the position of the bolt 38 is shifted from the center of the holding portion 34 (right side in FIG. 4), and the position below the holding portion 34 opposite to the bolt position is on the base 14. A ball plunger 42 is arranged. The ball plunger 42 has a ball 44 at the tip, and the ball 44 is urged by a spring 46 from behind. The ball 44 is provided so as to protrude from the mounting surface 16 of the pedestal, and the gap between the upper end of the ball and the lower surface of the holding portion 34 is smaller than the thickness of the leg portion 28 in the vertical direction. The ball plunger 42 is configured so that the ball does not protrude any further. The leg portion 28 of the mounted support column is positioned between the holding portion 34 and the base 14 in the vertical direction and between the bolt 38 and the ball plunger 42 in the circumferential direction.

  A gap d is formed between the tip surface 48 of each leg 28 and the inner peripheral surface 50 of the holding ring 20 (see FIG. 1). This corresponds to 2d in the diameter gap. Due to this gap, the support column 18 is allowed to move on the mounting surface 16. Further, the support column 18 can be made of an aluminum alloy, hard alumite can be applied to the surface thereof, and the porous structure can be impregnated with a fluororesin. The surface subjected to the taffram treatment has a Vickers hardness of 380 to 510, a low friction coefficient of 0.1, and is excellent in wear resistance. Moreover, heat resistance is also high and electrical insulation is also good.

  The pedestal 14 is provided with a vent 52 for improving the air flow when the coating liquid applied to the photosensitive drum base 12 is dried.

  In order to mount the support column 18 on the pedestal 14, first, the leg portion 28 of the support column 18 is aligned with the position of the receiving portion 36 of the holding ring 20, and then lowered onto the pedestal 14. Next, the support column 18 is rotated counterclockwise around its axis, and the leg portion 28 is inserted under the holding portion 34, that is, between the holding portion 34 and the base 14. At the initial stage of this rotation, the leg portion 28 comes into contact with the ball 44 of the ball plunger 42. When the support column 18 is further rotated, the ball 44 is pushed down against the urging force of the spring 46 while the top portion is pushed by the leg portion 28. Then, the leg portion 28 gets over the ball 44. In this state, the photosensitive drum base 12 is attached to the support column 18. Specifically, the photosensitive drum base 12 is lowered from above the support pillar 18. When the axes of the photosensitive drum base 12 and the support pillar 18 are misaligned, the bottom of the lowering photosensitive drum base comes into contact with the upper surface 32 that is the slope of one or two upper arms 26. By this contact, the support column 18 obtains a lateral component force, slides and moves on the mounting surface 16 of the pedestal, and absorbs the misalignment. The photosensitive drum base 12 is lowered until it comes into contact with the lower arm portion 22, and the mounting of the photosensitive drum base 12 is completed. The removal of the photosensitive drum base 12 from the support column 18 and the removal of the support column 18 from the pedestal 14 can be performed in the reverse order of the mounting procedure described above.

  The material of the pedestal 14, the support column 18, and the retaining ring 20 can be, for example, aluminum alloy, stainless steel, or the like. In addition, the arm portions 22, 24, 26 and the leg portion 28 of the support column 18 are shown extending in three directions. However, as long as the support column 18 itself and the photosensitive drum base 12 can be appropriately supported. It may extend in two directions, or may extend in four or more directions. The numbers of upper, middle, and lower arms and legs 28 do not need to match.

  The pedestal 14 was made of an aluminum alloy having a shape of 200 mm square and a material anodized on the surface. The support column 18 was made of aluminum alloy that was 60 mm in height, the upper arm portion 26 and the middle arm portion 24 had a diameter of 27.6 mm, and the leg portion had a diameter of 48 mm and was subjected to a turf treatment. The retaining ring 20 has an inner diameter of 51 mm, and the support column is allowed to move 3 mm in the radial direction. The photosensitive drum base 12 to be mounted has a diameter of 30 mm and a length of 253 mm.

  In a state where the photosensitive drum base 12 was held by the holder 10, it was conveyed to the coating tank for the undercoat layer. The photosensitive drum substrate 12 is removed from the holder, and 10 parts by mass of a zirconium compound (trade name: Orgatics ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.), 1 part by mass of a silane compound (trade name: A1110, manufactured by Nihon Unicar), i -After dip-coating for 2 minutes at 25 ° C in a coating solution consisting of 40 parts by weight of propanol and 20 parts by weight of butanol, this is taken out, held again in the holder 10 and dried by heating at 150 ° C for 10 minutes. A subbing layer of 5 μm was formed. Next, the photosensitive drum substrate 12 subjected to the above treatment is conveyed to a coating tank for a charge generation layer, and 1 part by mass of a chlorogallium phthalocyanine crystal is 1 part by weight of polyvinyl butyral resin (trade name: ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.). And 100 parts by mass of n-butyl acetate, and after dip coating at 25 ° C. for 2 minutes in a coating solution obtained by dispersing with glass beads for 1 hour with a paint shaker, this is taken out and held in the holder 10 Then, it was heated and dried at 100 ° C. for 10 minutes, and a charge generation layer having a thickness of 0.15 μm was formed on the undercoat layer.

Further, the photosensitive drum substrate 12 subjected to the above treatment is conveyed to a coating tank for the charge transport layer, and 3 parts by mass of polycarbonate resin (PCZ-300, manufactured by Mitsubishi Gas Chemical Company) and triphenylamine represented by the following structural formula (1) After 2 parts by mass of the derivative is immersed in 20 parts by mass of monochlorobenzene and applied by dip coating at 25 ° C. for 3 minutes, this is taken out and held on the holder 10 and heated at 120 ° C. for 1 hour. Drying was performed to form a charge transport layer having a thickness of 20 μm.

  When the electrophotographic photosensitive member (photosensitive drum) obtained above is mounted on a personal computer printer (trade name: PR1000, manufactured by NEC Corporation) and a print test is performed, white spots and black spots are generated. And an excellent image was obtained.

  As Comparative Example 1, the support column 18 was fixed to the pedestal 14, and an electrophotographic photoreceptor was obtained in the same manner as in Example 1 above. When the same electrophotographic photosensitive member was subjected to a printing test, black spots were generated, and a metal piece was observed when the surface of the photosensitive member corresponding to the black spot generating portion was observed.

  As Example 2, the inner diameter of the holding ring 20 or the diameter of the leg portion 28 is adjusted with respect to Example 1 so that the diameter gap is 1 mm, and an electrophotographic photoreceptor is produced in the same manner as in Example 1. And evaluated. There were no white or black spots.

  As Example 3, the inner diameter of the holding ring 20 or the diameter of the leg portion 28 is adjusted with respect to Example 1 so that the diameter gap is 5 mm, and the electrophotographic photoreceptor is manufactured in the same manner as in Example 1. And evaluated. There were no white or black spots.

  The evaluation results of the above examples and comparative examples are summarized in FIG.

It is a figure which shows schematic structure of the photosensitive drum base | substrate holder of this embodiment, and a photosensitive drum base | substrate. It is a schematic plan view showing the relationship between the support column 18 and the holding ring 20 of the holder. FIG. 6 is a perspective view showing a holding ring 20. It is an expanded sectional view by the AA line of FIG. It is a figure which shows the result of an Example and a comparative example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 (Photosensitive drum base | substrate) Holder, 12 Photosensitive drum base | substrate, 14 Base, 16 Mounting surface, 18 Support pillar, 20 Holding ring, 28 Leg part, 34 Holding part, 36 Receiving part, 38 Bolt, 42 Ball plunger, 48 Leg tip surface, 50 retaining ring inner peripheral surface.

Claims (6)

A photosensitive drum base holder for holding a cylindrical electrophotographic photosensitive drum base,
A pedestal having a flat mounting surface;
A support column mounted on the mounting surface of the pedestal and supporting the photosensitive drum base so that its axis is perpendicular to the mounting surface;
Holding the support column so as to allow a predetermined amount of movement on the mounting surface while maintaining its axis vertical, and a holding member fixed to the pedestal;
Having
A photosensitive drum base holder. The photosensitive drum base holder according to claim 1,
The support column extends outward in the radial direction, has a plurality of legs that contact the mounting surface of the pedestal and support the support column,
The holding member has an annular shape, and includes a holding portion that holds a leg portion of the support column between the base and a receiving portion that receives the leg portion of the support column,
A leg portion of the support column is inserted from the receiving portion of the holding member, and the support column is rotated so that the leg portion is positioned to face the holding portion of the holding member, and the support portion is a base. A photosensitive drum substrate holder mounted on the photosensitive drum substrate.   The photosensitive drum substrate holder according to claim 2, wherein the holding member has a facing surface at a position facing the leg tip of the support column, and a gap is formed between the facing surface and the leg tip. A photosensitive drum substrate holder, which is provided and is allowed to move the support column by the gap.   4. The photosensitive drum substrate holder according to claim 3, wherein a gap between a tip end of the support pillar and a surface of the holding member facing the support pillar is 0.5 to 2.5 mm. Photosensitive drum base holder. The photosensitive drum base holder according to any one of claims 1 to 4,
A part of the ball at the tip protrudes from the mounting surface, and a ball plunger in which the ball is biased by a spring from behind is provided on the base,
When the support column is rotated and mounted, the leg portion pushes down the ball against the urging force of the spring, gets over the ball, and reaches the position facing the holding portion. Base holder.   6. The photosensitive drum substrate holder according to claim 1, wherein a surface of the support column that comes into contact with the pedestal or the photosensitive drum substrate is subjected to a tumbling process. Drum base holder.

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