JPH11352834A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an appropriate image by preventing twist deformation of a base material while adopting the base material formed in a thin cylindrical shape by impact working. SOLUTION: This device is provided with an image carrier 11 equipping the image carrying layer formed on a surface of base material 11a in a thin shape furnished with flexibility, and with an abutting member 31 abutted on the surface thereof and becoming to a load with respect to the rotation of the image carrier, and moreover, the base material 11a is formed by the impact working for expanding and forming slug into the thin cylindrical shape by imparting the impact on the slug by a punch, and in the same time, rotary driving means 16 of the image carrier is, disposed on the end part in the side 11a2 opposite to the side on which the slug is arranged at the impact working time of the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a facsimile, and a copying machine for forming an image by using an electrophotographic technique, and more particularly, to an image carrier (for example, a photoconductor or an intermediate transfer body) and an image carrier thereof. It is related to drive technology.

[0002]

2. Description of the Related Art Generally, an image forming apparatus using an electrophotographic technique has a photosensitive member which has a photosensitive layer as an image bearing layer on the outer peripheral surface and is driven to rotate, and the outer peripheral surface of the photosensitive member is uniformly charged. Charging means for selectively charging the outer peripheral surface uniformly charged by the charging means to form an electrostatic latent image, and developing agent for the electrostatic latent image formed by the exposure means. Developing means for applying a toner to form a visible image (toner image), transferring means for transferring the toner image developed by the developing means to a recording material such as paper, and remaining on the photoreceptor surface after transfer. Cleaning means including a cleaner blade or the like for removing the remaining toner.

[0003] Since the photoreceptor in this type of image forming apparatus is degraded by an electric or mechanical shock, it is desirable that the photoreceptor is constituted as a replaceable consumable, and therefore it is desirable that the cost be low.

In order to meet such a demand, a method of manufacturing a metal drum for an image holding member described in JP-A-57-115560 is conventionally known.

FIG. 4 is a view showing an image holding member using a metal drum manufactured by the method described in the publication.

In FIG. 1, reference numeral 1 denotes a metal drum formed by impact cold extrusion (impact processing). An image holding layer 2 is formed on the surface of the metal drum 1. One end surface 1a of the metal drum 1 is processed for driving the image holding member, and a flange 3 is attached to the other end surface.

The end face 1a is adapted to mesh with a hook 5a of a connecting gear 5 attached to the main body 4,
The torque of the connecting gear is transmitted to the image holding member.

[0008]

Generally, as a developing means for applying toner to an electrostatic latent image formed on a photoreceptor, toner is carried on the surface of a developing roller. There is known a means of contacting a developing roller with a developing roller, or bringing the developing roller close to the developing roller at an extremely small interval. As a developing roller, a hard roller and a developing roller made of an elastic body are known.

A hard photosensitive drum is used as the photosensitive body,
Also, when a hard developing roller is used,
There is naturally a limit in manufacturing the photoreceptor drum and the developing roller with high precision, and errors always occur. Therefore, it is difficult to bring the two into uniform contact or close to each other with a uniform minute interval. In particular, it is extremely difficult to uniformly contact the photosensitive drum and the developing roller, which are hard members, and there is a gap locally, which causes uneven development, or the photosensitive drum and the developing roller are pressed more strongly than necessary. There is a problem that the roller is damaged.

Therefore, it is not usually practiced that both the photosensitive member and the developing roller are made of a hard material. When a hard photosensitive drum is used as the photosensitive member, the developing roller is made of an elastic material. When a hard developing roller is used, a photosensitive belt having flexibility is used as a photosensitive member.

However, when the developing roller is made of an elastic material, there is a problem that toner is scattered with the rotation of the developing roller.

When a photoreceptor belt is used as the photoreceptor, at least two rollers are required to support the photoreceptor belt, which not only complicates the structure but also increases the size of the apparatus. There's a problem.

On the other hand, utilizing the above-mentioned conventional technique (see FIG. 4), the metal drum 1 is formed in a thin shape, for example, at least a thickness 3 so that the metal drum 1 can be easily bent inward.
When the metal drum 1 is configured to be not more than 00 μm, the metal drum 1 can be used as a pseudo soft material. Therefore, even if the developing roller is hard, the metal drum 1 can be used without using a photosensitive belt. It can be expected that a reliable and stable contact state can be obtained.

[0014] However, the above publication does not disclose any use of the metal drum 1 as a pseudo soft material.

If the metal drum 1 is made thin enough to be used as a quasi-soft material in the prior art, the following problem occurs.

That is, as described above, an image forming apparatus generally using an electrophotographic technique is provided with a cleaner blade or the like for removing toner remaining on the surface of an image carrier after transfer of a toner image. Blade 6
(See the phantom line in FIG. 4) contacts the surface of the image carrier and scrapes off the toner remaining on the surface of the image carrier, and thus acts as a load on the image carrier that is driven to rotate. In other words, the cleaner blade forms a contact member that acts as a load on the rotation of the image carrier. Similarly, for example, when the charging unit or the like is configured by a charging roller or the like that rotates in contact with a photoconductor as an image carrier, the charging roller and the like also exert a load on the rotation of the photoconductor. The contact member is formed as follows.

In the configuration in which the contact member that acts as a load on the rotatably driven image carrier is disposed, the cleaner blade 6 and the metal blade 1 of the metal drum 1 as the base material of the image carrier are disposed. Contact portion and the drive side end portion 1a
And a torsional force acts on the portion 1b between them.

In such a situation, if the metal drum 1 is formed to be thin, the above-mentioned portion 1b
May be deformed, and when the deformation occurs, the contact between the image carrier and the cleaner blade 6 at the deformed portion becomes improper, and cleaning failure occurs. In addition, since the deformation occurs over the entire circumference of the metal drum 1 in the circumferential direction, the contact with another process member (not limited to a member serving as a load) such as a developing roller becomes inappropriate. Development failure and the like will occur.

An object of the present invention is to solve the above-mentioned problems and to form an image capable of forming an appropriate image by suppressing the deformation while using a base material formed into a thin cylindrical shape by impact processing. It is to provide a device.

[0020]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a thin cylindrical base material having flexibility; and an image bearing member formed on a surface of the base material. A thin, cylindrical image carrier having a layer, a rotation driving means for the image carrier provided at one end of the image carrier, and an image abutting on the surface of the image carrier. An image forming apparatus comprising a contact member acting as a load with respect to rotation of a carrier, wherein the base material of the image carrier expands the slag into a thin cylindrical shape by applying an impact to the slag with a punch. Along with the base material formed by the impact processing to be formed, the rotation driving means is provided at an end opposite to the side on which the slag is disposed at the time of the impact processing of the base material, I do.

[0021]

According to the image forming apparatus of the first aspect, the image carrier is rotationally driven by the rotation driving means provided at one end of the image carrier.

The image carrier has a flexible thin cylindrical shape having a flexible thin cylindrical base material and an image bearing layer formed on the surface of the base material. In other words, it can be used as a pseudo soft material, so that a hard developing roller or the like can be reliably and stably contacted.

Further, since the base material of the image carrier is formed by impact processing in which the slag is formed into a thin cylindrical shape by applying an impact to the slag with a punch, the base material can be made relatively inexpensively.

The strength of the thin cylindrical base material formed by impact processing is different between the side on which the slag is arranged during impact processing and the opposite side (the leading end in the extending direction). On the side where the slag is arranged, the crystal grain size becomes large and the strength becomes relatively low, and on the opposite side (the tip side in the drawing direction)
In this case, the crystal grain size becomes small and the strength becomes relatively high.

On the other hand, according to the image forming apparatus of the present invention, the rotation driving means of the image carrier is provided at the end opposite to the side on which the slag is arranged during impact processing of the base material. Therefore, a contact member (for example, a cleaner blade) that comes into contact with the surface of the image carrier and acts as a load on the rotation of the image carrier is provided. Even if a torsional force acts on a portion between the contact portion with the contact member and the drive-side end portion, deformation of this portion is prevented or significantly suppressed.

That is, according to the image forming apparatus of the first aspect, it is possible to form an appropriate image by suppressing the deformation while using a base material formed into a thin cylindrical shape by impact processing. .

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing a main part of an embodiment of an image forming apparatus according to the present invention, and FIG. 2 is a sectional view of a photosensitive unit.

First, an outline of the image forming apparatus will be described.

This image forming apparatus is an apparatus capable of forming a full-color image using a developing device using four color toners of yellow (Y), cyan (C), magenta (M), and black (K). .

In FIG. 1, reference numeral 10 denotes a photoreceptor unit (see FIG. 2), which has a photoreceptor 11 as an image carrier. The photoreceptor unit 10 is rotationally driven in a direction indicated by an arrow in FIG.

The photoreceptor 11 has a thin cylindrical conductive substrate 11a (see FIG. 2), which will be described in detail later, and a photosensitive layer 11b formed on the surface thereof.

Around the photoreceptor 11, along a rotation direction thereof, a charging roller 20 as a charging unit, a developing roller 21 (Y, C, M, K) as a developing unit, an intermediate transfer belt 22, and a cleaning unit Means 30 are arranged.

The charging roller 20 abuts on the outer peripheral surface of the photoreceptor 11 and is driven to rotate, thereby uniformly charging the outer peripheral surface of the photoreceptor 11. On the outer peripheral surface of the uniformly charged photoconductor 11, selective exposure L1 according to desired image information is performed by an exposure unit (not shown), and an electrostatic latent image is formed on the photoconductor 11 by this exposure L1. You.

The electrostatic latent image is developed with toner applied by a developing roller 21.

The developing roller 21Y for yellow, the developing roller 21C for cyan, the developing roller 21M for magenta, and the developing roller 21 for black
K is provided. These developing rollers 21Y, 21
C, 21M, and 21K are configured to be able to approach and separate from the photoconductor 11 by an unillustrated contact and separation mechanism, respectively.
Alternatively, only one developing roller 21 can contact the photoconductor 11. Therefore, these developing rollers 21 apply any one of yellow, cyan, magenta, and black toners to the surface of the photoconductor 11 to develop the electrostatic latent image on the photoconductor 11. Developing roller 21
Is constituted by a hard roller, for example, a metal roller having a roughened surface, or a hard resin roller.

The developed toner image is transferred onto the intermediate transfer belt 22 at the primary transfer section T1.

After the transfer, the cleaning means 30
A cleaner blade 31 for scraping off toner (not shown) remaining on the outer peripheral surface of the photoconductor 11 and a receiving portion 32 for receiving the toner scraped off by the cleaner blade 31 are provided.

The tip (edge) of the cleaner blade 31 is brought into contact with the surface of the photoconductor 11 by the urging force of the blade urging spring 33.

The intermediate transfer belt 22 includes a driving roller 23
And four driven rollers 24 (only one is shown), and is circulated in the direction of the arrow in the figure at substantially the same peripheral speed as the photoconductor 11.

The driven roller 24 shown in FIG.
The intermediate transfer belt 22 is disposed at a position where the intermediate transfer belt 22 is pressed against the photoconductor 11 by its own tension, and a primary transfer portion T1 is formed at a pressure contact portion between the photoconductor 11 and the intermediate transfer belt 22. .

In the course of circulating the intermediate transfer belt 22, the toner image on the photosensitive member 11 is transferred onto the intermediate transfer belt 22 in the primary transfer section T1, and the intermediate transfer belt 2
2 is transferred to a sheet (recording material) such as paper in a secondary transfer unit (not shown).

The sheet on which the toner image has been transferred in the secondary transfer section passes through a fixing device (not shown), where the toner image is fixed, and is discharged to an appropriate place, for example, a sheet receiving section of the apparatus main body.

The outline of the operation of the entire image forming apparatus as described above is as follows.

(I) When a print command signal (image forming signal) from a not-shown host computer or the like (a personal computer or the like) is input to the control unit of the image forming apparatus,
The photoconductor 11, the developing rollers 21, and the intermediate transfer belt 22 are driven to rotate.

(Ii) The outer peripheral surface of the photoconductor 11 is uniformly charged by the charging roller 20.

(Iii) The outer peripheral surface of the uniformly charged photoreceptor 11 is subjected to selective exposure L1 according to image information of the first color (for example, yellow) by an exposure unit, and a yellow electrostatic latent image is formed. Is formed.

(Iv) Only the developing roller 21Y for the first color (for example, yellow) comes into contact with the photoconductor 11, whereby the electrostatic latent image is developed, and the toner image for the first color (for example, yellow) is formed. Is formed on the photoconductor 11.

(V) A primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied to the intermediate transfer belt 22, and the toner image formed on the photoconductor 11 is transferred to the intermediate transfer belt 22 at the primary transfer portion T1. Is transferred to

(Vi) After the toner remaining on the photoreceptor 11 is removed by the cleaning unit 30, the photoreceptor 11 is discharged by the discharging light L2 from the discharging unit 25 (see FIG. 1).

(Vii) The above operations (ii) to (vi) are repeated as necessary. That is, the second color, the third color, the fourth color,
Are repeated on the intermediate transfer belt 22 to form a toner image corresponding to the content of the print command signal on the intermediate transfer belt 22.

(Viii) The sheet is supplied at a predetermined timing, and the toner image on the intermediate transfer belt 22 (basically, a full-color image in which four color toner images are superimposed) on the sheet at the secondary transfer unit. Is transferred to In addition,
The toner remaining on the intermediate transfer belt 22 after the secondary transfer is removed by a belt cleaner having a contact / separation mechanism (not shown).

Next, the photosensitive unit 10 will be described.

As shown in FIG. 2, the photosensitive unit 10
Is a pair of left and right shafts 12L and 12R,
L, 12R, respectively, and a pair of disc-shaped members 13L, 13R fixed to the pair of disc-shaped members 13L, 13R, respectively.
Both ends 1 are formed by the outer peripheral surface of the 13R and the fixing ring 14.
1c is supported and fixed, and is fixed to the thin cylindrical photoconductor 11 having flexibility and rotating together with the shaft 12 (L, R) and the disc-shaped member 13 (L, R), and to one disc-shaped member 13L. And a gear 16 as driving means.

The outer diameter of the outer peripheral surface of the disc-shaped member 13 is formed to be slightly larger than the inner diameter of the photoconductor 11, and the disc-shaped member 13 is press-fitted into the end of the photoconductor 11. A tapered surface is formed inside the disk-shaped member 13 so that the press-fitting is performed smoothly. With this press fit,
The photoreceptor 11 and the disc-shaped member 13 are connected substantially satisfactorily, but a fixing ring 14 is provided to further secure the connection between the two. The fixing ring 14 includes a ring-shaped disk portion 14a and a short cylindrical portion 14b integrated therewith.
And The disk portion 14a is provided with a plurality of (for example, eight (only one is shown)) screw insertion holes 14c at equal intervals in the circumferential direction. Cylindrical part 14b
The end 11c of the photoreceptor 11 and the outer portion of the disk-shaped member 13 are press-fitted into the nip. A slightly inclined tapered surface is formed on the inner peripheral surface of the cylindrical portion 14b so that the press-fitting is performed smoothly.

First, the disc-shaped member 13 is press-fitted into the end portion 11c of the photoreceptor 11, and then both are fixed to the fixing ring
(The fixing ring 14 is attached to the photosensitive member 1).
1), and the fixing ring 14 is fixed to the disc-shaped member 13 with the screws 15, thereby being completely fixed to the disc-shaped member 13.

The photosensitive member 11 is formed by forming a photosensitive layer 11b on the surface (outer peripheral surface) of a flexible conductive base material 11a. Since the photosensitive layer 11b is extremely thin, it is not clearly shown in the drawing.

The substrate 11a is made by impact processing.

FIG. 3 is an explanatory diagram of impact processing.

First, a slag (a piece of metal to be processed) 41 is set on a die 50 as shown in FIG. As the slag 41, aluminum or an alloy containing aluminum as a main component is used.

Next, as shown in FIG.
At 1, the slag 41 is impacted. Then, the slag 41 is instantaneously expanded into a tubular shape, and a tubular body 42 is formed.

Thereafter, as shown in FIG.
When 1 is pulled up, the upper end 42a of the tubular body 42 comes into contact with the stripper 52, and the tubular body 42 comes off the punch 51,
The cylindrical body 42 is obtained.

The cylindrical body 42 thus obtained is cut off along the cutting lines C1 and C2 (see FIG. 3C) at the end 42b on the slag 41 side and the upper end 42c to cut the base material 11a. Is obtained.

The photosensitive layer 11b as an image bearing layer is formed on the surface of the substrate 11a by coating (for example, dipping) or the like, and the photosensitive member 11 is obtained.

The flexibility, ie, the flexibility, of the photoconductor 11 can be determined by adjusting the thickness and the diameter of the substrate 11a. It is possible to set. For example, the thickness is appropriately set within the range of the base material thickness of 20 to 300 μm and the base material diameter of 10 to 300 mm. Since the photosensitive layer (OPC) is mainly made of resin, it is excellent in flexibility, but in order to secure adhesion to the base material and to take measures against laser light interference, the distance between the base material and the OPC is reduced. It is desirable to form an undercoat layer on the substrate. As the undercoat layer, a layer in which particles capable of absorbing laser light such as zinc oxide and titanium oxide are dispersed in a resin such as a nylon resin is preferable.

The thin cylindrical base material 11a formed by the impact processing is used for the slag 4 during the impact processing.
The strength is different between the side 11a1 (see FIG. 3 (c)) on which 1 is disposed and the opposite side (extending end side) 11a2. On the side 11a1 on which the slag 41 is arranged, the crystal grain size becomes large and the strength becomes relatively low, and on the opposite side (extending end side) 11a2, the crystal grain size becomes small and the strength becomes relatively high.

Therefore, in this embodiment, as shown in FIG. 2, the gear 16 serving as the rotation driving means of the photosensitive member 11 is
It is provided at the end of the side 11a2 opposite to the side on which the slag 41 is arranged during impact processing of the base material 11a.

The gear 16 is formed separately from the disc-shaped member 13L, and is fixed to the disc-shaped member 13L by a plurality of (for example, three (only one is shown)) screws 17. .

The photoreceptor unit 10 assembled as described above is detachably mounted on the image forming apparatus as shown in FIG. 1, and in the mounted state, the driving gear of the main body of the image forming apparatus is mounted on the gear 16. (Not shown) mesh with each other, so that they are driven to rotate in the direction of the arrow.

According to the above-described image forming apparatus, the following operational effects can be obtained.

The photoconductor 11 is driven to rotate by a gear 16 provided at one end of the photoconductor 11.

The photosensitive member 11 has a flexible thin cylindrical shape having a flexible thin cylindrical base material 11a and an image bearing layer 11b formed on the surface of the base material 11a. Therefore, it can be used as a pseudo soft material, so that the hard developing roller 21 and the like can be reliably and stably contacted.

Further, the base material 11a is formed by impact processing in which the slag 41 is formed by applying an impact to the slag 41 with the punch 51 to form the slag into a thin cylindrical shape, so that the base material 11a can be produced at a relatively low cost.

The thin cylindrical base material 11a formed by the impact processing is used for the slag 4 during the impact processing.
The strength is different between the side 11a1 on which No. 1 is disposed and the opposite side (extending end side) 11a2. On the side 11a1 on which the slag 41 is arranged, the crystal grain size becomes large and the strength becomes relatively low, and on the opposite side (extending end side) 11a2, the crystal grain size becomes small and the strength becomes relatively high.

On the other hand, according to the image forming apparatus of this embodiment, the drive gear 16 of the photosensitive member 11 is
Is provided at the end of the side 11a2 opposite to the side on which the slag is disposed at the time of impact processing of the photoconductor 1
A cleaner blade 31 or the like that comes into contact with the surface of the photoconductor 11 and acts as a load on the rotation of the photoconductor 11 is provided.
Even if a torsional force acts on a portion 11e (see FIG. 2) between the contact portion 11d (see FIG. 2) and the drive-side end portion, deformation of the portion 11e is prevented. Alternatively, it is significantly suppressed.

That is, according to the image forming apparatus of this embodiment, it is possible to form an appropriate image by suppressing the deformation while using the base material 11a formed into a thin cylindrical shape by impact processing. .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the present invention.

For example, in the above-described embodiment, the description has been made by taking the photosensitive member as an example of the image carrier. However, the intermediate transfer member (the toner image on the photosensitive member is primarily transferred, and the toner image is transferred to a recording material such as paper) Cylindrical transfer body for secondary transfer on paper)
It can also be applied to

[0079]

According to the image forming apparatus of the first aspect,
It is possible to form an appropriate image by suppressing the deformation while using the base material formed into a thin cylindrical shape by impact processing.

[0080]

[Brief description of the drawings]

FIG. 1 is a schematic view showing a main part of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view of a photoconductor unit.

FIGS. 3A, 3B, and 3C are explanatory diagrams of impact processing.

FIG. 4 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 Reference Signs List 11 image carrier (photoconductor) 11a base material 11b photosensitive layer (image carrier layer) 16 gear (rotation driving means) 31 cleaner blade (contact member) 41 slug 51 punch

Claims (1)

[Claims] 1. A flexible thin cylindrical image carrier having a flexible thin cylindrical base material and an image bearing layer formed on the surface of the base material. An image forming apparatus comprising: an image carrier rotation driving unit provided at one end of a carrier; and a contact member that abuts on the surface of the image carrier and acts as a load on the rotation of the image carrier. The base material of the image carrier is a base material formed by impact processing of forming a slag into a thin cylindrical shape by applying an impact to the slag with a punch, and the rotation driving unit includes: An image forming apparatus, which is provided at an end opposite to a side where a slag is arranged at the time of impact processing of a base material.