JPH065446B2 - Cleaning device - Google Patents

Description

The present invention relates to a cleaning device, and more particularly to a cleaning device, which is used in an electrophotographic copying device, an electrophotographic printer, or the like, for removing residual toner adhering to the surface of an image carrier. Related to the cleaning device.

[Prior art]

Generally, in a cleaning device, the cleaning blade used has a thickness of 2 to 5 mm and a free end length of about 10 to 20 mm made of polyurethane, and has a rubber hardness of 60 to 80 Hs. It was

And as an element for determining such a value,
The cleaning blade has a uniform contact property with the photosensitive drum, which is an image bearing member, a cleaning property of the developer, and an abrasion resistance of the cleaning blade.

Then, in order to uniformly contact the cleaning blade with the photosensitive drum, it is necessary to press the distal end against the photosensitive drum with a load of a certain amount or more in order to cover the unevenness of the front end. Even in the case of the trail method in which the toner is inclined to the uncleaned side, and in the case of the counter method in which the image carrier is inclined to the already cleaned side, the toner must be contacted with the photosensitive drum under appropriate conditions. Is located at the tip pressing part of the cleaning blade or slips through this part, abnormal vibration (squeaking) of the cleaning blade, excessive abrasion of the photoconductor drum, and excessive wear of the cleaning blade may occur. It was

The cleaning blade is generally made of polyurethane and has a thickness of 1 mm or more. However, a drawback in this case is that the cleaning action depends on the force of blocking the pressing of the photoconductor drum. There were many cases where the contact part was crushed.

That is, as shown in FIG. 7, the toner 22 is discharged between the tip of the cleaning blade 21 and the photoconductor drum 20 due to the improper pressing of the photoconductor drum 20 as the image carrier or the poor precision of the cleaning blade tip. If the pressing force is increased in order to prevent the entering and slipping, the toner particles are rubbed against the toner due to this, or the toner adheres to the surface of the photosensitive drum (so-called black spot). There was a cleaning failure such as.

Then, for example, in the case of the trail method shown in FIG. 8, the cleaning blade 21 for the photosensitive drum 20 as a whole when the load is applied to a certain extent or more, especially when the tip portion bends and is attached and actually used. Therefore, the angle of the cleaning blade 21 with respect to the photoconductor drum 20 becomes large because the ideal angle γ within a certain range cannot be secured during actual use. It was loose {φ in Fig. 9 (a)}, or became small {φ 'in Fig. 9 (b)}.

Then, if the load is too high, there is a drawback that the entire cleaning blade bends to cause abdominal shearing and the toner easily slips through, and when the angle is increased to prevent the abrading of the cleaning blade. Has a drawback that abnormal vibration is likely to occur if the angle is too large, and further, the higher the load, the more severe the abrasion of the photosensitive drum and the friction of the cleaning blade,
Each repair and replacement period is shortened, and the size of the motor is increased to increase the rotation torque of the photoconductor drum, thus increasing the overall cost. The disadvantages of US Reissue Patent No. 29632 and US Reissue Patent No. 30924
It was a defect common to those shown in the issue.

In order to eliminate these drawbacks, Japanese Patent Laid-Open No. 56-5559.
79, JP-A-55-151680 and JP-A-59.
No. 101689 has been proposed, and the one disclosed in JP-A-56-55979 is a composite structure having a rubber elastic substrate and a hard resin layer, that is, cleaning with a multi-layer blade. Although it constitutes a blade, it has the drawback that the structure of laminating the rubber elastic substrate and the hard resin layer is complicated, and that the bonded parts are unstable due to changes in the surrounding environment and are easily peeled off. However, it has a drawback that it becomes remarkable under the condition of high humidity, the cleaning performance is affected, and the rubber elastic substrate is deteriorated.

Further, the one disclosed in Japanese Patent Laid-Open No. 55-151680 has a structure in which resin plate blades mixed with carbon fibers or fiber blades having different directions are laminated, Is insufficient in flexibility, and therefore, it is difficult to make uniform contact with the photoconductor drum, the precision of the pressing tip (edge precision) is difficult to obtain, and the cost is increased. Had.

Further, the one disclosed in Japanese Patent Laid-Open No. 59-101689 has a structure of a flexible thin plate attached to the tip of an elastic blade. Since the flexible thin plate is pressed and abutted against the photosensitive drum by force, the adhesive member with the elastic blade is unstable and easily peeled off especially under conditions of high temperature and high humidity, and the elastic blade itself deteriorates, and cleaning is performed. It had the drawback of affecting performance and therefore impracticality.

[Object of the Invention]

The present invention eliminates the above-mentioned drawbacks of the conventional ones and allows uniform abutment with a low load, so that it has sufficient cleaning performance, and can be made compact and inexpensive. It is an object of the present invention to provide a cleaning device which has excellent wear resistance of the abutting tip portion and excellent durability as a whole and therefore can perform good cleaning for a long period of time and has a simple structure. .

Another object of the present invention is to provide a cleaning device having excellent cleaning characteristics by improving scratches on an image carrier, which is a drawback of thin plate blade cleaning of resin and metal.

[Structure of Invention]

The present invention is a cleaning device for removing residual toner on the surface of an image bearing member by pressing the tip of a cleaning blade to remove the toner. The cleaning blade is made of resin, metal or ceramics and has a thickness of 50 μm. .About.300 .mu.m supporting layer and a 10 .mu.m to 200 .mu.m thick elastic layer formed of a rubber-like elastic body are combined to form a thin plate, and the elastic layer is brought into contact with the surface of the image carrier. is doing.

Example of Invention

 Embodiments of the present invention shown in the drawings will be described below.

FIG. 1 shows an embodiment of a cleaning device according to the present invention. The cleaning system of the cleaning device is a trail system, and inside the casing 2 in which one pair of the photosensitive drum 1 is open, A toner conveying screw 3 is provided in the lower portion, and a guide roller 4 located above the toner conveying screw 3 and in contact with the photosensitive drum 1 is provided.

A spring 6 is attached to the upper part of the casing 2 and hangs downward from an external support frame 5, and a support member 7 is attached to the lower end of the spring 6, and the lower surface of the support member 7 is attached. A thin blade 8, which is a cleaning blade, is attached to the tip portion via a double-sided tape.

This thin blade 8 is made of polyethylene terephthalate (P
ET) biaxially oriented polypropylene, polyimide {Kapton (manufactured by DuPont), TI polymer (manufactured by Toray)}, a resin made of polyacetal, polybutylene terephthalate, polyamide or the like, or a support layer 8a made of metal, ceramics or the like. , A composite layer with an elastic layer 8b made of polyurethane rubber, silicon rubber, fluorine rubber or the like.

Further, the thickness _{h p} of the support layer 8a of the thin blade 8 as shown in Figure 2 are applied those 30Myuemu～500myuemu, particularly preferably has a 50 m to 300 m,
The thickness _{h e} of the elastic layer 8b are applied those 5Myuemu～500myuemu, in particular, those of 10μm~200μm is preferred.

The thickness h of the thin blade 8 is 60 μm.
Those having a thickness of up to 500 μm are preferably applied.

Further, in the relation between the free end length l and the thickness h of the thin plate blade, the range of 5 ≦ l / h ≦ 50 is applied, and particularly 10 ≦ l /
The range of h ≦ 30 is preferable.

In this case, the preferable range of the thickness h varies slightly depending on the material of the cleaning blade, but there is a limit due to the strength of the material, the strength of the waist, and the difficulty of work such as mounting the cleaning blade and assembling. It has a drawback that it is easily bent, and therefore, it can be easily made with a thickness of 60 μm or more.

Further, when uniformly abutting on the photosensitive drum as a cleaning blade, it is necessary to have some flexibility.
A material of 500 μm or less is suitable because a general-purpose material can be used.

Further, the reason for the application range of 1 / h is that if the cleaning blade has a thickness h within the above range, the cleaning blade can be easily brought into uniform contact with the photosensitive drum.

Further, the tip of the thin blade is brought into contact with the surface of the photosensitive drum by the spring 6, and the vertical load component F _N of the tangent line of the photosensitive drum at the contact point is 5 to 60 g / in the case of the trail method. cm, 1 for counter type
It is ~ 40g / cm.

The rubber hardness of the elastic layer 8b is 50 in JIS hardness.
A degree or more is applied, preferably 70 to 90 degrees. The tip of the contact portion of the composite layer with the photosensitive drum was cut from the elastic layer side.

An example using the cleaning device configured as described above will be described below.

[Experimental Example-I]

In this experimental example, a cleaning device as shown in FIG. 3 was used.

That is, in this cleaning device, a toner conveying screw 3 for recycling is provided in the lower portion of the casing 2 which is open on the side of the photosensitive drum 1, and a toner guide plate which is inclined downward from above to below the opening portion. 10, a toner scraping member 11 is provided on the toner guide plate 10, and a supporting member 12 having a rear end supported.
At the rear end, a spring 13 is provided whose front end pushes down the upper end of the upper surface of the support member 12, and a cleaning blade (thin blade) 8 is attached to the lower surface of the front end of the support member 12.

The thickness _{h p} of the supporting layer 8a of the cleaning blade 8 made of polyethylene terephthalate (PET)
= 250 [mu] m, and an elastic layer 8b and the thickness _h e = 100 [mu] m made of polyurethane rubber, the free end length l = 7 mm,
γ = 50 °, blade length 460 mm, F _N = approximately 45 g
/ Cm, rubber hardness 80 degrees (the same applies to the following examples), and the spring 13 is a phosphor bronze leaf spring.

The photosensitive drum 1 made of selenium and amorphous silicon was subjected to 20,000 times of copying and 50,000 times of copying respectively. As a result, in any case, the cleaning blade 8 was attached with the spring 13. The photosensitive drum 1 can be brought into uniform abutment in cooperation with the power.
It was possible to reliably remove the toner on the surface of, and a good cleaning result could be obtained. Furthermore, the cleaning operation could be continued without any change, that is, without replacing the cleaning blade.

[Experimental Example-II]

In this experimental example, a cleaning device as shown in FIG. 4 was used.

That is, this cleaning device is almost the same as that used in the embodiment-I, and the same members are designated by the same reference numerals and the description thereof will be omitted. A guide roller 15 is provided in contact therewith, and a scraping base 16 is also provided.

The supporting layer 8a of the cleaning blade 8 is made of polyester resin {trade name (made by Toray) Lumirror} and has a thickness h _p = 100 μm, and the elastic layer 8b is made of polyurethane rubber and has a thickness h _e = 100 μm.
The photosensitive drum 1 is an organic photosensitive member (Japanese Patent Application No. 59-108225).
A carrier-generating substance containing a bisazo compound as a main component, a styryl compound, and a carrier-transporting substance containing at least one of an amine derivative as a main component). Development is performed with a component developer, the speed of the cleaning blade 8 with respect to the surface of the photosensitive drum 1 is 142 mm / sec, the contact angle γ with the photosensitive drum 1 is 45 °, and F _N is 35 g.
/ Cm.

Under such conditions, the thickness h of the cleaning blade is 2
In 00Myuemu, and when the free end length l is 4 mm, apart from _{this, h p = 100μm, h e} = 125μm, h = 225
For [mu] m, and _{h p = 75μm, h e =} 50μm,
20,000 copies or more were carried out for the case of h = 125 μm and the free end length l of 3 mm and 3.5 mm, but the cleaning blade 8 is always made uniform on the surface of the photosensitive drum 1 in cooperation with the urging force of the spring 13. Since the contact was made possible, the surface of the photosensitive drum could be cleaned well.

Incidentally, FIG. 5 shows a modification of the one shown in FIG. 4, which has a structure in which the biasing member 13 provided as a separate member from that of FIG. 4 is removed. Even if it is configured as described above, it can sufficiently function.

Further, FIG. 6 shows a case of a counter method using a thin plate blade of a composite layer, and the same members as those of the trail method are designated by the same reference numerals and the description thereof will be omitted. Even in the case of such a counter method, the same result as in the case of the trail method could be obtained. Reference numeral 17 is a charging device, and 18 is a transfer / separation device.

Note that the present inventor considers that in a cleaning blade for removing the residual toner on the image bearing member, a very small portion of the tip of the blade contacting the image bearing member is particularly important, and thus resin, metal, etc. The object of the present invention can be achieved by providing the supporting layer, which is a thin plate, with an elastic layer made of an elastic material such as rubber to the required thickness, and bringing only the elastic layer into contact with the image carrier. Is.

〔The invention's effect〕

According to the present invention, as described above, the cleaning blade is made of resin, metal or ceramics and has a thickness of 50 μm.
Since the supporting layer having a thickness of up to 300 μm and the elastic layer having a thickness of 10 μm to 200 μm formed of a rubber-like elastic material are combined to form a thin plate, the cleaning blade has an appropriate rigidity and also has an image bearing property of the cleaning blade. The part that contacts the body has rubber-like elasticity.

Therefore, the tip of the cleaning blade can be kept in contact with the surface of the image carrier at a predetermined angle for a long period of time, and the pressing load acts directly on the elastic layer through the support layer to apply an extra load. Even if it is not necessary, good cleaning performance can be exhibited, so that a low load can be maintained.

Therefore, friction and crushing of the tip portion of the cleaning blade are reduced, durability is improved, good cleaning performance can be maintained for a long period of time, and a high load is not applied to the image carrier. It has excellent effects such as small size and low cost.

[Brief description of drawings]

FIG. 1 is a schematic layout view showing a cleaning device according to the present invention, FIGS. 2 (a), (b) and (c) are enlarged views showing a main part of FIG. 1 and a perspective view, and FIG. 3 shows an experiment. FIG. 4 is a schematic layout view showing a cleaning device according to the present invention which has been carried out, FIG. 4 is a schematic layout view showing a cleaning device according to the present invention which has been subjected to another experiment, and FIG. FIG. 6 is a schematic layout diagram showing another method, FIG. 7 is an enlarged view showing a contact portion between a conventional cleaning blade and a photosensitive drum, and FIG. 8 is a photosensitive drum of a conventional cleaning blade. 9 (a) and 9 (b) are schematic views showing a contact state with the body drum, respectively, showing a case where the contact angle of FIG. 8 is large and a case where the contact angle is small. 1, 20 ... Photosensitive drum 2 ... Casing 3 ... Toner conveying screw 4, 15 ... Guide roller 5 ... Support frame 6, 13 ... Spring 7, 12 ... Support member 8, 21 ... Cleaning blade (Thin blade) 8a ... Support layer 8b ... Elastic layer 10 ... Toner guide plate 11 ... Toner scraping member 16 ... Scraping base 17 ... Charging device 18 ... Transfer / separation device 22 ... Toner

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinkazu Fukuchi 2970 Ishikawa-cho, Hachioji-shi, Tokyo Inside Rokusha Konishi Industrial Co., Ltd. (72) Shunji Matsuo 2970 Ishikawa-cho, Hachioji-shi, Tokyo Shinroku Konishi Kogyo Co., Ltd. (56) Reference JP 57-105764 (JP, A) JP 57-133470 (JP, A) JP 58-182675 (JP, A) JP 58-203480 (JP , A)

Claims (1)

[Claims] 1. A cleaning device for removing residual toner on the surface of an image bearing member by pressing the tip of a cleaning blade to remove the toner, wherein the cleaning blade is formed of resin, metal or ceramics. A support layer having a thickness of 50 μm to 300 μm and a thickness of 10 μm to 200 formed from a rubber-like elastic body.
A cleaning device comprising: a thin plate-shaped composite with a μm elastic layer, and contacting the elastic layer with the surface of the image carrier.