JPH044591B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cleaning device for an electrostatic recording device that uses a photoconductive photoreceptor such as selenium or a dielectric material such as polycarbonate as a toner image carrier, and further relates to More specifically, the present invention relates to a blade cleaning device that uses a blade to remove residual toner on the surface of a toner image carrier.

[Background of the invention]

In an electrostatic recording device using a photoconductive photoreceptor with a smooth surface such as selenium, an organic photoconductor, or cadmium sulfide, or a dielectric material such as polycarbonate, the surface of the photoconductive photoreceptor or dielectric material, that is, the toner image carrier It is necessary to clean the toner remaining on the surface.

An effective cleaning method is to use an elastic blade. There are two types of conventional blade cleaning devices shown in FIGS. 1 and 2. For example, a plate-shaped elastic blade 2 supported by a holder 3 is in contact with a toner image carrier 1, which has a drum shape and rotates in a clockwise direction, with A as a contact point. Among the angles formed by the contact surface XX to the toner image carrier 1 at point A and the plane YY including the blade surface where the holder 3 holds the blade 2, the angle 1a on the side where the toner image carrier pair enters the contact point If the angle is φ, it can be divided into two types: φ>π/2 and φ<π/2.

(1) φ＞π/2 (Fig. 1) In this type, as the toner image carrier moves, the blade is moved by the frictional force that acts between the toner image carrier and the blade. The blade is flexed and compressed from the twisting point in the rotational direction (retreat side), and the reaction force causes the edge portion of the blade to press against the surface of the toner image carrier with a large force. Therefore, the residual toner cleaning power is great, but the disadvantage is that excessive force is applied to the surface of the toner image carrier, which may damage the surface. In addition, the frictional force acts as a compressive force in the direction in which the blade is installed in the holder, and appears as flapping of the blade due to slight fluctuations in the frictional force and release of the accumulated compressive force, causing cleaning sideways on the surface of the image carrier. Unevenness occurs.

(2) φ<π/2 (Fig. 2) Due to the frictional force between the blade and the surface of the toner image carrier, a strong reaction force from the blade does not act, and there are problems like the method (1). However, the surface cleaning power is weak and cleaning defects tend to occur easily.

Furthermore, in this method, as φ is increased to approach π/2, cleaning performance generally improves, and the phenomenon of toner filming, in which toner components adhere to the surface of the toner image carrier and form a film, is less likely to occur. However, vibrations are likely to occur due to repeated accumulation and release of bending moments acting on the blade, resulting in uneven cleaning and making it difficult to uniformly press the blade against the surface of the toner image carrier.

Further, in order to suppress the above-mentioned vibration problem, φ may be made small, but if it is made small, the cleaning force becomes weak and toner filming is more likely to occur. Furthermore, foreign objects such as carriers are likely to be caught between the toner image carrier and the blade, causing scratches on the surface of the toner image carrier.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a blade cleaning device that eliminates the above-mentioned two types of blade cleaning defects and provides stable and good cleaning performance.

[Structure of the invention]

The above object of the present invention is to provide a blade cleaning device that removes residual toner by pressing an elastic cleaning blade against the surface of a toner image carrier, in which the elastic cleaning blade presses the edge of the cleaning blade via an elastic buffer to remove the toner image. A rigid pressing substrate that presses against the carrier surface is provided, and on the side where the toner image carrier surface enters the pressing contact point, the intersection angle between the contact surface of the pressing contact point to the toner image carrier surface and the half surface including the cleaning blade surface is set to an acute angle. This is achieved by a blade cleaning device that is characterized in that it is installed.

The present invention will be specifically explained below using the drawings.
FIG. 3 is a schematic diagram of an electrostatic recording device equipped with the blade cleaning device of the present invention.

In the figure, reference numeral 1 denotes a toner image carrier, which is in the form of a drum. Reference numeral F denotes an electrostatic latent image forming means that forms an electrostatic latent image on the surface of the toner image carrier 1 based on an electrical or optical image sent from an image pickup means (not shown) of the document. The electrostatic latent image is developed into a toner image by a developing device D.

T is the toner image transfer means, and the recording paper (not shown) carried in from the paper feed means T1 receives the toner image transfer at the transfer peeling electrode section T2, and the toner image carrier 1 is transferred to the recording paper (not shown). The toner image is peeled off from the surface and conveyed to fixing means (not shown) by the conveying means T3, and the toner image is fixed on the recording paper, completing recording. Note that the transfer means T may also be of a type in which the toner image is once transferred to an intermediate transfer body and then transferred again to recording paper.

On the other hand, untransferred toner remains on the surface of the toner image carrier 1 that has passed through the transfer means T, and the residual toner is removed by the cleaning device C and transferred to the electrostatic latent image forming means F. The surface of the toner image carrier 1 that enters again is cleaned so as not to interfere with the formation of an electrostatic latent image. The degree of cleaning of the surface affects the quality of the recorded image (degree of fogging, ghost images, etc.), and it is the cleaning device that performs the cleaning, and therefore the cleaning device is responsible for determining the quality of the image. Determine. On the other hand, the suitability of its functional structure also influences the degree of damage to the toner image bearing member 1, which is an important point in performing electrostatic recording, and is the reason for carrying out the present invention.

Among the above-mentioned cleaning devices, a blade cleaning device of the present invention that performs cleaning with a blade will be explained with reference to the drawings. FIG. 4 shows an example of a blade portion of an embodiment of the present invention.

A toner image carrier (hereinafter referred to as carrier) 1 rotates clockwise, and residual toner on the carrier after transfer is removed by a blade cleaning device. Elastic blade (hereinafter abbreviated as blade)
2 is the plane YY including the blade surface and the blade 2
and the contact surface of the carrier 1 at the push contact point A of the carrier 1
The carrier 1 is arranged so that the intersection angle φ with XX becomes an acute angle 0<φ<π/2 on the entry side 1a of the carrier surface with respect to the pressing contact point A.
is pressed against by a pressing means (not shown).
The blade 2 is held between a blade holder piece 31 and a rigid pressing board (hereinafter referred to as the board) 32, and an elastic buffer (hereinafter referred to as the buffer) is provided between the blade 2 and the board 32. 5 and is biased and buffered.

When the carrier 1 starts rotating in the direction of the arrow in the figure, the blade 2 pressed against the surface of the carrier 1 is caused by the frictional force between the blade 2 and the carrier 1.
is dragged in the rotational direction of the carrier 1, and the entire blade holder 3 is also subjected to a force displacing in the rotational direction of the carrier 1.
By providing the stopper 6 in contact with the blade holder 3, displacement of the entire blade holder 3 is regulated. When this state is reached, the buffer body 5 provided between the back surface of the blade 2 and the substrate 32 receives compressive force due to the deformation of the blade 2. A reaction force to this compressive force acts on the blade 2. In particular, since the buffer body 5 generates a reaction force against the bending of the blade from the back surface of the blade 2, the reaction force in response to the deformation of the blade becomes very noticeable, and the killing effect is significantly improved. In contrast to the drawback in the case of 0<φ<π/2 in that there is almost no reaction force against blade deformation from the blade, by providing the buffer 5 on the pressing edge of the blade 2 as in the present invention, 0<φ As the blade is pressed against the blade deformation of <π/2, and a local pressing force is applied over the entire edge of the blade according to the deformation of each part, the cleaning ability is dramatically improved and the toner is removed. The blade 2 is pressed uniformly against the surface of the carrier 1 without causing filming or vibration of the blade,
Uniform cleaning becomes possible. Further, the foreign matter can be removed without applying localized strong pressure to the surface of the carrier 1, and there is no risk of damaging the surface of the carrier 1, making it extremely suitable for blade cleaning.

For the blade 2, conventionally known synthetic rubbers such as urethane, silicone, nitrile, neoprene, or perflon, or natural rubber can be used. Moreover, the above-mentioned materials can of course be used alone, and the above-mentioned materials may also be used as a multilayer material, or a steel plate or the like may be used in combination for elastic reinforcement.

The shape of the blade may be rectangular in cross section taken along a plane that is perpendicular to the contact surface XX of the carrier surface at the push contact point A and includes the moving direction of the surface, or
It may also have a wedge-shaped protrusion facing toward the carrier. Other pressing force, friction coefficient, thickness, wear,
Various convenient shapes can be given in consideration of fatigue durability and the like. Further, the longitudinal direction of the blade along the width direction of the carrier may be simply parallel to the width direction, or may be installed at a certain angle. In this case, if the carrier is a drum, the blade edge will have a helical shape on the cylindrical surface of the drum.

Next, the buffer body 5 that biases and buffers the blade 2 has a rectangular, elliptical, or circular cross section shaped to match the space between the blade 2 and the substrate 32, and is filled with air or liquid. An elastic tube having the above-mentioned cross section, rubber having the above-mentioned cross section, sponge having closed cells, or the like may be used, or an elastic mechanism made of a coil spring or a steel plate may be used.

A plurality of shock absorbers 5 may be installed if necessary.

In addition, a pressure contact member for the buffer body 5 is provided on the substrate 32, and by pressure contacting the buffer body 5, the blade 2
It is also possible to use a mechanism that adjusts the force with which the blade 2 presses the surface of the carrier 1.

Although the air-filled elastic tube described above is a simple buffer, it generates an appropriate pressing force based on Pascal's principle even when the blade is unevenly deformed, and it also acts uniformly over the entire blade. Therefore, the blade 2 always presses uniformly against the carrier, which is convenient.

In order for the blade 2 to exert a cushioning pressing force on the surface of the carrier 1 due to the biasing force provided by the buffer body 5 described above, a base point of the pressing force is required. That is, the holder 3 holding the blade 2 maintains a constant posture in a constant relation position range with respect to the carrier 1, thereby
It must be regulated so as to counteract the frictional force between the blade 2 and the surface of the support pair 1.

FIG. 5 shows an embodiment of the posture regulating means for the holder 3. Holder piece 31 that clamps and fixes the blade 2
The substrate 32 is screwed onto a holder base material 33 to form the holder 3. The holder base material 33 is fitted onto a fixing member 4 that is immovably fixed relative to the carrier 1, is rotated around the fixing member 4 to press the blade 2 against the surface of the carrier 1, and is then retracted. The eccentric cam stopper 6a, which had been in place, is lowered to press the base plate 32, and a rough adjustment pressing force is generated at the pressing contact point A. Next, fine adjustment is made to the optimum pressing force using the eccentric cam stopper 6a. An example of the mechanism of the eccentric cam stopper is illustrated in FIG. By lowering the eccentric cam stopper 6a and pressing the eccentric cam 62a against the base plate 32 to fix the height of the cam shaft 61a, and then rotating the lever 63a around the cam shaft 61a, the eccentric cam 62a is stopped. Turn the lever, finely adjust the pressing force, and insert the lever 6 into the fixing hole 64a.
Fix 3a. Note that a mechanism may be adopted in which the eccentric cam 62a is biased using the lever 63a as a base point to further apply a cushioning pressing force to the holder 3.

FIG. 7 shows another embodiment of the posture regulating means for the holder 3. The stopper 6b consists of a fine adjustment screw 62b and a stop member 61b. As before, a coarse adjustment pressing force is applied to the push contact A by the stop member 61b, and then fine adjustment is performed by the fine adjustment screw 62b.

The means for regulating the posture of the holder 3 may include, in addition to the two-stage regulation of coarse and fine adjustment as described above, a one-stage regulation means that automatically provides a damping effect. Examples thereof are illustrated in FIGS. 8 and 9.

In FIG. 8, a fixing member 4c fixed immovably relative to the carrier 1 is inserted into the holder 3, and a spring 6c with a large spring constant is applied to the holder base material portion on the opposite side of the blade 2 with respect to the fixing member 4c. This applies a pressing force that also has cushioning properties to the push contact point A.

Further, in the example shown in FIG. 9, a slide rod 4d is provided which is a modification of the fixing member fixed immovably in the same manner as described above, and furthermore, the slide rod 4d can be fitted into the holder base material of the holder 3, and A sliding hole is provided that allows free sliding, and the blade 2 is connected to the slide rod 4d.
A weight 6d of a constant weight is attached to the holder base material on the opposite side. A pressing force with optimum cushioning properties is applied to the push contact point A by the balance between the inclination of the slide rod 4d and the weight of the weight 6d.

As a means of regulating the posture of the holder 3, the simple stopper 6 shown in FIG. 4 can be used to prevent damage to the surface of the carrier 1 by the action of the buffer body 5 and the blade 2, and to achieve the purpose of cleaning. It can be implemented by adjusting the conditions to achieve the desired results.

〔Effect of the invention〕

The present invention has been described in detail above.According to the present invention, the drawbacks that conventionally occur when the intersection angle φ is φ<π/2 and φ>π/2 are solved; (1) Damage to the carrier surface is avoided. (2) Pressure contact with the carrier surface is always uniform; (3) A stable state can be maintained despite vibration; (4) Toner filming does not occur. We can propose a blade cleaning device with dramatically improved performance.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of two types of blade cleaning devices regarding the intersection angle between the blade surface and the surface in contact with the toner image carrier, and FIG. 3 is an electrostatic recording device equipped with the blade cleaning device of the present invention. FIG. FIG. 4 is an explanatory diagram with the blade portion according to the present invention taken out; FIGS. 5 and 6 are explanatory diagrams of an example of the two-stage adjustment posture regulating means of the holder;
The figure is an explanatory diagram of an example of another two-stage adjustment posture regulating means. Further, FIGS. 8 and 9 are explanatory diagrams of an embodiment of the one-stage adjustment posture regulating means of the holder. 1... Toner image carrier, 2... Elastic blade,
3...Holder, 4...Fixing member, 5...Elastic buffer, 6...Stopper, A...Press contact.

Claims (1)

[Claims] 1. In a blade cleaning device that removes residual toner by pressing an elastic cleaning blade against the surface of a toner image carrier, the elastic cleaning blade presses the edge of the cleaning blade via an elastic buffer and is pressed against the surface of the toner image carrier. It is characterized by comprising a substrate, and on the side where the toner image carrier surface enters the push contact point, the intersecting angle between the contact surface of the push contact point to the toner image carrier surface and a plane including the cleaning blade surface is set at an acute angle. Blade cleaning device.