JPH0425866A - Image forming device - Google Patents

Abstract

PURPOSE:To integrally constitute a developing device and a photosensitive body by providing a gap holding member at the end of a developing sleeve, injecting and solidifying rubber material in the holding member and allowing the holding member to press-contact with the end of a photosensitive body. CONSTITUTION:After the rotary shafts 9B at both ends of the developing sleeve 9A are inserted in the escape holes 91 of casing 90 and spacers 92 being the gap holding members are supported by bearings on the outside, the outside and an escape hole 31 are communicated so as to integrate the casing 90 with the guiding member 4 of the photosensitive body. Then, the liquid rubber material is press-injected from an injection port 32A on the bottom of a space part 93, and solidified while it is discharged little by little from a discharge port 32B in a state where inner pressure is kept, thereby setting the gap between the outer peripheral surface of the developing sleeve 9A and the photosensitive surface of a photosensitive belt 1 at a specified value.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention develops a latent image on a belt-like image forming member by an electrophotographic method using a developing device provided at the peripheral portion of the belt-like image forming member to form a toner image. The present invention relates to an image forming apparatus that obtains an image by transferring it onto a transfer material.

C. Background of the invention] There are many methods and techniques for obtaining color images using electrophotography.
A device has been proposed. For example, Japanese Patent Publication No. 61100770
As disclosed in the publication, a latent image is formed and developed in the number of separated colors of the original image on a photoreceptor drum serving as an image carrier, and is transferred onto a transfer drum each time it is developed. One method is to form a multicolor image and then transfer it onto recording paper to obtain a color copy. A device using this method requires a transfer drum large enough to transfer one sheet of image onto its circumferential surface in addition to the photoreceptor drum, and the device does not have a large and complicated structure. Inevitable.

For example, as disclosed in Japanese Unexamined Patent Publication No. 149972/1982, a latent image is formed and developed on a photosensitive drum according to the number of separated colors of the original image, and is transferred onto a transfer material each time it is developed. This method is used to obtain multicolor copies. With this method, it is difficult to overlap multicolor images with high precision, and it is impossible to obtain high-quality color copies.

Another method is to repeatedly form a latent image on a photoreceptor tram in accordance with the number of separated colors of an original image and develop it with color toner, and then overlap the color toner images on the photoreceptor drum and transfer the images to obtain a color image. The basic process of forming a multicolor image is disclosed in Japanese Patent Application Laid-open No. 60-75850 and No. 60-7 by the present applicant.
No. 6766, No. 60-95456, No. 60-9545
No. 8, No. 60-158475, etc.

In a multicolor image forming apparatus that obtains a color image by such superimposition, a plurality of developing units containing different colored toners are arranged around the periphery of the photoreceptor tram. The photoreceptor drum is rotated multiple times to develop the latent image on the photoreceptor drum to obtain a color image.

Regarding the image forming body, as explained above, 1 to 1 are photoconductor drums whose plum surfaces are coated or vapor-deposited with a photoconductor, and belt-shaped image forming bodies in which the photoconductor is coated or mounted on a flexible belt. A belt-like image forming body (hereinafter also referred to as photoreceptor belt) has its shape determined by being stretched between rotating rollers including a driving roller, so space can be used effectively. This is effective when configuring an image forming apparatus with a compact shape.Also, since the photoreceptor belt can run along a small curvature,
By using a rotating roller with a small diameter and using this curvature to separate the transfer material, it is possible to prevent defective separation of the transfer material.

[Purpose of the invention]

In a color image forming device using a photoreceptor belt,
Image forming means such as a charging means, an image exposing means, and a developing means consisting of a plurality of developing device groups are provided at the peripheral edge of the photoreceptor belt, and a certain gap is provided between the second image forming means and the rotating photoreceptor belt. They will face each other with

A method has been proposed in which a backup roller is used as a means for opposing the image forming means to the photoreceptor belt while maintaining a constant distance therebetween, and a hack-up roller is used to oppose the image forming means to the photoreceptor belt. However, if a backup roller is used (and in some cases, a number of bathoquarn rollers corresponding to the number of image forming means are provided, many rollers are required. Also, when the number of rollers is large, it is necessary to It is also difficult to maintain parallelism.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 57-34576, a device for opposing the photoreceptor belt on the kite member has been proposed, but it is difficult to maintain the distance using such a device.

In the case of a 1j ram-shaped photoreceptor, regarding the developing device that is the image forming means, a roller that rotates as a gap holding member is provided coaxially with the developing roller, and the developing device is pressed against the drum-shaped photoreceptor. Things are being done.

On the other hand, in the case of a belt-shaped photoreceptor, it is technically difficult to press the rollers onto a flexible belt, so a spacing member is usually brought into contact with a support that supports the belt. Setting the gap between the photoreceptor and the developing roller.

The spacing member used in this case does not need to be a rotatable roller, but a simple abutting member may be used.
In order to ensure that the abutment member abuts against the support and maintains the two states, each developing device is assembled in a state in which it is individually biased toward the support through an elastic member.

Therefore, as in the case of using a tram-shaped photoreceptor, each developing device can be constructed integrally with the photoreceptor side, and although converterization can be realized, the actual situation is that it is not possible to greatly simplify the structure.

As a result of solving and improving this point, the present invention realizes a means for individually biasing the above-mentioned spacing members against the support, thereby forming an image in which a developing unit can be configured on the photoreceptor side and the body. The purpose is to provide equipment for two purposes.

[Structure of the Invention] The above object is to provide a belt-like image forming member that moves on a support;
and a developing device having a developing sleeve that rotates in opposition to the developing sleeve, wherein an end of the developing sleeve is provided with a gap holding member that abuts the end of the support;
The gap maintaining member is achieved by an image forming apparatus characterized in that the gap maintaining member is in pressure contact with the end portion of the support by an injected and solidified rubber material.

〔Example〕

An embodiment of the color image forming apparatus of the present invention is shown in FIGS. 1 to 3.

In FIG. 1, ``■'' is a visible photoreceptor belt which is a belt-like image forming member, and the photoreceptor belt 11 is installed between rotating rollers 2 and 3. conveyed in the direction.

Reference numeral 4 denotes a support member or guide member fixed to the main body of the apparatus so as to be inscribed in the photoreceptor belt 1, and the photoreceptor belt 1 is kept under tension by the upward mechanical action of the tension roller 5. The inner circumferential surface is rubbed by the guide member 4.

Therefore, the photoreceptor on the outer peripheral surface of the photoreceptor belt 1 (and the surface of the guide member 40) is always maintained in a constant position relative to the surface of the guide member 40 even during conveyance, making it possible to form a stable image forming surface.

Reference numeral 6 denotes a scorotron charger as a charging means, 71 a laser writing unit as an image exposure means, and 8 and 11 denote a plurality of developing means, that is, developing units each containing a developer of a specific color. Each of the image forming means is disposed facing the outer peripheral surface of the photoreceptor belt l with the kite member 4 on the back side.

Each of the above-mentioned developing devices, together with a charger 6 and a cleaning device 13 to be described later, are integrally fixed and incorporated into a process cartridge nozzle 30 that accommodates the photoreceptor belt 1.

In addition to the optical system shown in the drawings, the laser writing system unit 7 may also include an optical system that integrates a light emitting section and a convergent light transmission body.

Each of the developing units 8.9.10.11 accommodates, for example, yellow macenter, cyan, and black developers, respectively, and each of the developing sleeves 8A, 9A maintains a predetermined gap from the photoreceptor belt 1. , IOA, 1.1At-@, has a function of making the latent image on the photoreceptor belt 1 visible by a non-contact development method. This non-contact development is different from contact development,
It has the advantage of not interfering with the movement of the photoreceptor belt.

12 is a transfer device, 12A is a static elimination bar, 13 is a cleaning device, and a plate 1' 13A and a toner conveying roller 13B of the cleaning device 13 are connected to a photoconductor belt I- during image formation.
The photoreceptor belt 1 is kept at a position apart from the surface of the photoreceptor belt 1, and is pressed against the surface of the photoreceptor belt 1 as shown in the figure only during cleaning after image transfer.

The process of forming a color image by the color image forming apparatus is performed as follows.

First, the formation of a multicolor image according to this embodiment is performed according to the following image forming system. That is, data obtained by a color image data input section that scans an original image with an image sensor is processed by an image data processing section to create image data, which is then stored in an image memory. The image memory is then taken out during recording and inputted into a recording section, for example, the color image forming apparatus shown in the embodiment shown in Figure $1.

That is, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit 7, the color signal is generated by a semiconductor laser (not shown) in the laser writing system unit 7. The laser beam is rotated and scanned by a polygon mirror 7B rotated by a drive motor 7A, passes through an f-theta lens 7C, and has its optical path bent by mirrors 7D and 7E. The light is projected onto the circumferential surface of the body belt 10 to form a bright line.

On the other hand, when scanning is started, the beam is detected by the index sensor, modulation of the beam by the first color signal is started, and the modulated beam scans the circumferential surface of the photoreceptor belt 1. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the photoreceptor heald 1 by the main scanning by the laser beam and the sub-scanning by the conveyance of the photoreceptor bell l-1. This latent image is created using yellow (Y) toner (
The toner image is developed by the developing device 8 loaded with a developing medium (developing medium), and a toner image is formed on the drum surface. The obtained toner image, while being held on the drum surface, passes under a cleaning device 13, which is a cleaning means, which is separated from the circumferential surface of the photoreceptor belt 1, and enters the next copy cycle.

That is, the photoreceptor belt l is charged again by the charger 6, and then the second color signal output from the signal processing section is input to the writing system unit 7, and the above-mentioned first color signal is Writing on the ram surface forms a latent image. The latent image is developed by a developer 9 loaded with magenta (M) toner as a second color.

This magenta (M) toner image is formed in the presence of the previously formed yellow (Y) toner image.

1O is a developing device containing toner (C), which forms a toner image (C) on the drum surface based on a control signal generated by a signal processing section.

Furthermore, 11 is a developing device having black toner, and forms a black toner image superimposed on the heald surface by the same process. These developing units 8, 9, 10 and 11
Direct current or even alternating current bias is applied to each of the sleeves, and numping development is performed using a two-component developer, which is a developing means, and development is performed without contact with the photoreceptor heald 1, which is grounded to the substrate. It's becoming. Incidentally, as the development, non-contact development using a -component developer can also be used.

The color toner image thus formed on the circumferential surface of the photoreceptor belt 1 is transferred to the transfer material fed from the paper feed collars 71 and 14 via the paper feed kite 15 in the transfer section.

That is, the transfer material housed in the paper feed cassette 14 is conveyed by the rotation of the paper feed roller 16, and one sheet of the top layer is carried out via the timing roller 17 in synchronization with the image formation on the photoreceptor belt l. It is supplied to the transfer device 12.

The transfer material that has undergone image transfer and static electricity removal is transferred to the rotating roller 2.
The image is reliably separated from the photoreceptor belt l, which suddenly changes direction along the direction, and moves upward, and after the image is fused by the fixing roller 18, it is ejected onto the tray 20 via the ejection roller 19.

On the other hand, the photoreceptor belt 1, which has completed the transfer to the transfer material, continues to be conveyed and remains in the cleaning device 13 where the blade 13A and the toner conveying roller 13B are brought into pressure contact. At this point, the blade 13A is pulled away again, and a little later, after smoothing out the toner accumulated on the tip of the toner supply roller 1.3B or plate 13A, the supply roller 13B is pulled away and a new image forming process begins. enter.

The guide member 1 has a conveyance surface on which the photoreceptor bells and the photoreceptor bells slide into one curved surface with a relatively thick radius of curvature R, and further has the image forming means of the curved surface facing each other. The portion is formed into a plurality of small curved surfaces having a radius of curvature l smaller than the radius of curvature R.

Therefore, the photoreceptor bell +-1 comes into contact with the kite member 4 only at the tops of the small curved surfaces, and a reliable sliding state is maintained due to uniform pressing force. As a result, the photoconductor surfaces of the photoconductor healds 1 facing each image forming means are always correctly set at predetermined positions, and during conveyance, due to the effect of reducing frictional resistance, the photoconductor is conveyed smoothly at a predetermined speed.

In the one-way developing device 1, the relationship between the developing sleeve and the photosensitive surface of the photoreceptor heald 1 is regulated by pressing each spacing member against the kite member 4, which will be described later. A development area is formed and the non-contact development described above is performed.

The structure and function of each developing device will be explained using developing device 9 as an example.

FIG. 2 shows the details of the developing device 9, and FIG. 3(a) shows its cross section along arrow AA.

In the figure, 9A is the developing sleeve containing the magnet roller, 9B is its rotating shaft, and developing sleeve 9A is the rotating shaft 9.
It is driven and rotated by the power system of the main body of the apparatus via the gear 9C at the end of the B axis in the same conveying direction as the photoreceptor belt j, that is, in the counterclockwise direction in FIG. 3.

90A is a rigid and magnetic thin layer forming member that is pressed against the developing sleeve 9A with a predetermined load without the presence of developer. Reference numerals 90B and 90C are a pair of toner conveying screws that have a screw structure and transport and circulate the developer in opposite directions, and function to sufficiently stir and mix toner and carrier and send the resulting developer to the developing sleeve 9A. .

The toner conveyance screw 90B and the toner conveyance screw 90C are members that also serve as stirring members that rotate in opposite directions.The toner and carrier conveyed to the back side by the thrust of the toner conveyance screw 90B are
- The toner conveying screw 90C side is moved and its thrust conveys the toner to the front side of the drawing, and the mixing action of the toner and carrier during this time makes it a homogeneous developer that is triboelectrically charged, and the toner is transferred onto the circumferential surface of the developing sleeve 9A. It adheres to the surface in a layered manner.

This developer layer adheres to the circumferential surface of the developing sleeve 9A in the form of a thin layer, and forms a latent image on the circumferential surface of the photoreceptor belt 1, which is conveyed one turn clockwise in the developing area, at the above-mentioned development interval. A toner image is formed by non-contact reversal development.

During this non-contact development, a power supply (not shown) is used to connect the developing sleeve 9 to the developing sleeve 9, which contains an AC component in addition to a DC component.
A is applied to the latent image, and only the toner in the developer is selectively transferred and adhered to the surface of the latent image on the formed image block 9A.

The developer that has consumed the toner components has a high carrier ratio and is transported by the developing sleeve 9A to the scraper 9.
It is peeled off and collected by 0D, and a developer with a high toner ratio is mixed again.

As shown in FIG. 3(a), the rotating shaft 9B at both ends of the developing sleeve 9A was inserted through the escape hole 91 of the caning 90 of the developing device 9, and the bearing supported a spacer 92 serving as a spacing member on the outside thereof. Later, the outer part of the process cartridge 30 is inserted into the relief holes 31 of the front and rear boards 30A and 30B constituting the process cartridge 30, and then the guide member 4 and the casing 90 are inserted into the board 3OA.
, 30B is fixed and integrated.

The spacer 92 is housed in a space 93 formed by the canon 90 and each substrate so that it can slide only in the vertical direction, and the spacer 92 is developed at a position where its top comes into pressure contact with the abutting portion 4A provided on the guide member 4. The gap between the outer peripheral surface of the sleeve 9A and the photosensitive surface of the photosensitive member holder 1 is set to a predetermined value.

The pressing action of the spacer 92 against the abutting portion 4A is performed as follows.

An injection port 32A and a small diameter discharge port 32B are provided at a position on each substrate corresponding to the bottom of the space 93 (.
Liquid rubber material is press-fitted from the injection port 32A, and while a small amount of comb material is discharged from the discharge port 32B, the rubber material in the space 93 is solidified while maintaining a constant internal pressure.

As a result, the spacer 92 receives the elasticity of the solidified rubber material and its top portion is strongly pressed against the protrusion 4A, and this state is maintained semi-permanently.

The above-mentioned comb material may be one that easily solidifies at room temperature, such as liquid silicone rubber.

Also, the magnetic roller 9 included in the developing sleeve 9A
Regarding the support of D, for example, if it is a fixed type, a bearing supports the support shaft 9E of the magnet roller 9D on the inner periphery of the rotating shaft 9B of the developing sleeve 9A, as shown in the figure.
Furthermore, by engaging the shaft end of the front support shaft 9E with an elongated hole elongated in the vertical direction of the support plate 33 integrated with each board,
It is always used stationary in a concentric position with respect to the developing sleeve 9A.

FIG. 3(b) is an explanatory view showing the side surface of the guide member 4 seen from the direction of arrow B in FIG. 3(a), and shows the abutting portion 4.
A is the developing sleeve of each developing device (indicated by a - dotted line)
The spacers 92 are formed at respective positions corresponding to the abutting portions 4A, and the spacers 92 are pressed against the respective abutting portions 4A after bearings support the respective developing sleeves and integrate them as described above.

〔Effect of the invention〕

According to the present invention, the belt-shaped image forming body unit and the developing device unit can be integrated with an extremely simple structure, and as a result, extremely stable developing conditions can be obtained, and it is also highly durable. An image forming device will be provided.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the image forming apparatus of the present invention, Fig. 2 is a sectional view of the developing device, Fig. 3(a) is a view of its main parts, and Fig. 3(a) is a sectional view of the developing device.
b) is a side view of the main part of the kite member. 1... Photoreceptor belt 4... Guide member 4A...
- Abutting portion 6... Charger 13... Cleaning device 8.9.10.11... Developing device 8 A, 9 A, IOA, llA... Developing sleeve 9B... Rotating shaft 9C... Gear 9D... Mag non-separation roller E OA 2B 92 Support shaft process force 30B... Substrate V1 output loss spacer cartridge 32A... Inlet 90... Casing 93... Space

Claims (2)

[Claims] (1) In an image forming apparatus including a belt-like image forming body that moves on a support and a developing device having a developing sleeve that rotates opposite to the belt-like image forming body, an end of the developing sleeve has an end of the support. An image forming apparatus characterized in that a gap holding member is provided in contact with the end of the support, and the gap holding member is in pressure contact with the end portion of the support by an injected and solidified rubber material. (2) The image forming apparatus according to claim 1, wherein the developing device is constructed integrally with the support body.