JPH0473597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blade device and a cleaning device used in an image forming apparatus such as an electrophotographic device.

Conventionally, in image forming apparatuses such as electrophotographic apparatuses, a developed image is formed on the surface of an image carrier such as a photoreceptor or an insulator, and after transfer, the surface is cleaned and reused. For example, in an electrophotographic copying machine, first, an optical image corresponding to the original is projected onto a photoconductive photosensitive layer provided on the circumferential surface of the drum to form an electrostatic latent image, and then a developer is applied to this latent image. A toner image is formed by the adhesion. Furthermore, the transfer material is pressed against the photosensitive drum, and the image on the drum is transferred. Finally, this is fixed and a copy is created. After transfer, the drum is cleaned of residual toner by a cleaning device and is ready for the next image formation. As a cleaning device, there has conventionally been a blade cleaning method. In this method, a wear-resistant rubber material is usually brought into pressure contact with the surface of the photoreceptor, and the toner remaining on the surface of the photoreceptor is removed by friction at the edge of the rubber material. The device based on this method has a simple structure and can be made compact, so it is very useful as a cleaning device for electrophotographic copying machines.

By the way, the cleaning blade is generally held by inserting the blade between two parallel flat plates and compressing the blade to a predetermined thickness using screws or the like. However, the drawback is that the compressive stress depending on the screw position becomes uneven, and the positional accuracy of the edge ridge line that contacts the image carrier may become non-uniform in the direction of the generatrix where the image carrier contacts.

Therefore, as one method to solve this problem, a method of bonding the blade and the holding member has been proposed. Although this method of bonding the blade to the holding member can eliminate the above-mentioned problems, other problems also arise. This will be explained below with reference to the drawings.

In FIG. 1, 1 is a photosensitive drum, and arrow a
rotating in the direction. A cleaning blade 2 is brought into contact with this surface 1a, and this blade 2 is bonded to a holding member 3. This holding member 3 is generally made of a metal plate, plastic, or the like. However, it is generally difficult to produce sharp, right-angled ridge lines with these materials due to sagging during cutting and sagging during plastic molding. As an example of this, FIG. 2 shows a side view of a holding plate made by pressing a metal plate. In this case, the tip of the A side of the holding member 3 forms an R surface called a so-called sag, and the tip of the B side forms a protruding portion D called a burr. When the blade 2 is bonded and attached to such a member 3 such as a plate via the adhesive layer 4, the above-mentioned pull-out R portion is caused by insufficient adhesion between the blade 2, the adhesive layer 4, and the holding member 3. This causes uneven adhesion. FIG. 3 is a perspective view showing this situation as a model, and the shaded area 5 is the part that is firmly bonded. In such a configuration, the force applied to the blade is applied in the direction of arrow F in Figure 2, but if there is uneven adhesion as described above, the load is concentrated on the bonded part, and therefore the force F Even if the blade is weak, it will easily separate from that part, and if partial separation occurs, the load will be further concentrated locally, and this will continue to cause the blade to separate easily from the retaining plate.
In this way, when the adhesive layer peels off, even before the blade falls off, the length of the blade from the fixed end (l in Figure 2) effectively increases, and the pressure applied to the photosensitive drum decreases, causing extreme In this case, the contact pressure becomes 0. Therefore, the cleaning function no longer works. On the other hand, if the blade is attached to the B side of FIG. 2, that is, the burr side, the blade will lift up due to the burr, creating a gap. Alternatively, the tip of the holding plate 3 may be machined with high precision, but this would result in very poor productivity and would be impractical.

In order to solve the above-mentioned problems, the present invention provides a cleaning blade device having a cleaning blade and a holding member that holds the cleaning blade through an adhesive layer, in which the holding member is punched and the above-mentioned adhesive The layer is provided at a position away from the tip of the holding member, and the present invention also provides a cleaning blade for removing residue on an image bearing member, and a cleaning blade using the cleaning blade. A cleaning device having a holding member held via an adhesive layer, wherein the holding member is blown, and the adhesive layer is provided at a position away from the tip of the holding member. It is something.

A first embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a sectional view showing an example of a cleaning device to which the present invention is applied.

Reference numeral 1 denotes an image carrier, which is an example in which a photoreceptor containing a photoconductive material such as selenium (Se) or an organic photoconductor (OPC) is supported in the form of a drum. The drum-shaped image carrier 1 rotates in the direction of arrow a. A corona discharger 6 uniformly charges the surface of the image carrier 1. 7 is an optical means such as a short focus optical element array, which irradiates a light image onto the image carrier 1. A developing device 8 develops an electrostatic latent image formed on the image carrier 1 in response to light image irradiation. A timing roller 9 functions to send the transfer material 10 fed from a paper feeding means (not shown) to the transfer position in synchronization with the development on the image carrier 1. 11 is a transfer material guide, and 12 is a transfer corona discharger. A transfer corona is applied to the back surface of the transfer material 10 by a transfer corona discharger 12 to perform transfer onto the transfer material 10.
A conveyor belt 13 guides the transfer material 10 after the transfer is completed to a fixing means (not shown). 14 is a cleaning device to which an embodiment of the present invention is applied; 21 is an elastic cleaning blade made of urethane rubber or plastic; and 15 is a sheet-like guide member for storing removal materials such as residual developer removed by the blade; It leads into the box 15a.

FIG. 5a is a detailed sectional view of the cleaner 14 shown in FIG. 4. Note that FIG. 5b is a perspective view showing the blade portion. In the figure, the toner remaining and adhering to the surface of the photosensitive drum 1 after the transfer process is scraped off by a rubber blade 21, and a receiving member made of, for example, a polyester film with a thickness of about 75 μm is located below the rubber blade 21. It is stored in the container 15a using the scooping sheet 16. This scooping sheet 16 is in light contact with the surface of the drum 1, and the degree of contact is such that the residual toner can pass through this sheet.

This contact of the sheet 16 with the drum prevents the toner scraped off by the blade 21 from leaking from inside the container 15a to the outside. Further, numeral 17 at the bottom of the cleaning device 14 is a magnet for collecting toner that has fallen to the outside.

A part of the interior of the cleaning device 14 is partitioned by a fixed partition plate 18, and the toner dropped by the blade 21 as described above is collected by a rotating scraping member 19 into a space 20 on the back side of the container.
be pushed into. By doing so, the apparent density of the toner can be increased and the container can be made smaller. The scraping member 19 is made of an elastic body such as a polyester sheet or rubber-impregnated cloth, for example.

Now, the blade 21 is adhered and fixed to the holding member 23 at the surface that contacts the image carrier through an adhesive layer 24 forming an adhesive area. Further, the holding member 23 is positioned with a positioning pin 25 and fixedly held on the outer frame 26 of the cleaning device 14 with screws or the like. In this embodiment, the adhesive layer 24 is not provided on the entire surface of the holding member 23 that is in contact with the blade 21, but is formed on a portion spaced a certain distance d from the tip 23a of the holding member 23. By doing so, the adhesion between the blade 21 and the holding member 23 is maintained uniformly, and a decrease in adhesive strength is prevented, and the adhesion does not peel off due to the force exerted on the blade 21 from the drum 1. Specific examples are shown below.

A 1.6 mm thick iron plate is used as the holding member 23,
Blade 21 is made of polyurethane rubber (rubber hardness 65°)
was held on the grooved side of the iron plate by adhesive. The adhesive forming the adhesive layer 24 is a tape-shaped SBR (styrene butadiene resin) adhesive, which is first preliminarily adhered to the holding member 23, then overlapped with the blade 21, and the holding member 23 is heated at 100°C.
It was bonded by applying a pressure of 30 kg/cm ² while heating it. At this time, the adhesive layer 24 was provided in a flat area that was not affected by sagging (provided on the inner side at a distance of d=2 mm from the tip).

Next, an experimental example will be shown to prove the effects of the present invention.

The durability of the cleaning device shown in the above example and the cleaning device in which the adhesive layer was provided up to the end of the holding member were compared.

After adhesion, press the blade against the photosensitive drum 1,
At this time, both were set so that a pressure of 50 g/cm was applied to the blade. Afterwards, put it in an atmosphere of 45℃.
After leaving it for a few days, I actually made a copy and confirmed its operation. The results show that when a cleaning device with an adhesive layer extending to the edges makes copies of 1,200 to 1,300 sheets, the adhesive peels off locally in an area approximately 1 to 2 mm from the edges, which impairs cleaning performance. caused. On the other hand, the cleaning device to which the present invention was applied, in which the adhesive layer was provided 2 mm from the edge, did not peel off the adhesive even after conducting a durability test of making 3,000 copies, and the cleaning performance remained good until the end.

Further, by providing the adhesive layer on the holding member at a position away from the tip end on the side of the object to be contacted, as in the present invention, the following advantages can also be obtained.
That is, if the coefficient of friction between the blade and the photosensitive drum is very large, the blade will be dragged by the drum, and in extreme cases, the blade will be reversed, as shown in FIG. 6a. In order to prevent this, in the configuration shown in Figure 6a, the length of the holding plate toward the drum can be increased; however, in this case, the length from the fixed end of the blade to the tip (hereinafter referred to as free light) As a result, the pressure of the blade that presses against the photosensitive drum becomes too strong, resulting in image problems such as fusion of the developer to the surface of the photosensitive drum. However, FIG. 6b to which the present invention is applied
By adopting the configuration shown in Fig. 6c, it is possible to lengthen the holding plate without changing the free length l of the blade, and even when the friction coefficient between the drum and the blade increases as described above, it is possible to As shown in the figure, the tip d region of the holding member acts as a blade reversal stopper to prevent the blade from reversing.

Next, a second embodiment of the present invention is shown in FIG.

In the embodiment shown in FIG. 7, the photosensitive drum 1 rotates in the forward direction relative to the blade 21. In the embodiment shown in FIG.

Even in the above embodiment, the holding member 21 does not need to be made of metal such as an iron plate, and may be made of plastic. In this case, it is difficult to create a clean right-angled surface by molding, etc., and if burrs appear, the blade will lift up there during bonding, which is undesirable. In such a case, reliable adhesion and holding can be achieved by giving the edge a curvature of, for example, 0.5 to 1 mm from the beginning and adhering only to the flat area (indicated by d in the figure) away from that part.

Note that the adhesive is not limited to the above embodiments, and may be a hot melt type, a cyanoacrylate type instant adhesive, a double-sided tape, or the like. Further, in the embodiment shown in FIG. 5, the blade was bonded to the surface of the holding plate having the sag, but as shown in the side view of FIG. If the thickness t ₂ of the adhesive layer 34 is kept larger than the height t ₁ of the abnormal protrusion, it is also possible to adhere to a surface having abnormal protrusions such as a burr. be.

Note that the present invention is applicable not only to the case where the blade is adhesively held to the holding member on the surface that contacts the image carrier;
It can also be applied to the case of adhesive holding on a non-contacting surface, or the case of adhesion and holding on a contacting surface and a non-contacting surface. In addition, as long as the blade can contact the image carrier and obtain sufficient cleaning performance,
The material is not limited to a plate-like material, but may be chip-shaped, claw-shaped, rectangular, etc., and as long as the material has elasticity, rubber such as urethane or plastic resin (elastomer) can be used. Further, as the holding member, any suitable member can be used as long as it can hold the blade in sufficient contact with the image carrier, such as an arm-shaped member or a plate-like member.

As explained above, in the case of adhering the blade and the holding member, the present invention makes it possible to hold the blade stably and reliably by providing the adhesive layer at a certain distance from the tip of the holding member that contacts the blade. As a result, it has become possible to provide a compact cleaning device that provides stable cleaning performance.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of the cleaning device, Fig. 2 is a side view thereof, Fig. 3 is a perspective view, and Fig. 4 is a sectional view showing an example of the cleaning device.
The figures are schematic cross-sectional views showing an example of an electrophotographic apparatus embodying the present invention.
The figures are a sectional view showing a cleaning device to which one embodiment of the present invention is applied, FIG. 5b is a perspective view of a blade portion, and FIG. 8 is a side view of another embodiment. In the figure, 1 is a photosensitive drum, 2, 21 are cleaning blades, 3, 23 are blade holding members, 4, 2
4 indicates an adhesive layer.

Claims (1)

[Scope of Claims] 1. A blade that contacts an object to be contacted, and a holding member that holds this blade through an adhesive layer, the adhesive layer being a tip of the holding member on the side of the object to be contacted. 1. A blade device used in an image forming apparatus, characterized in that the blade device is provided at a position apart from the blade device. 2. The blade device according to claim 1, wherein the holding member is formed by punching. 3. A cleaning blade that comes into contact with the image carrier to remove residue on the image carrier, a holding member that holds the cleaning blade via an adhesive layer, and a receiver that receives the residue removed by the blade. A cleaning device for use in an image forming apparatus, comprising: a member, wherein the adhesive layer is provided at a position apart from a leading end portion of the holding member on the image carrier side. 4. The cleaning device according to claim 3, wherein the holding member is formed by punching.