JPS6052885A - Toner remover having device for regulating press contact force - Google Patents

Abstract

PURPOSE:To enable satisfactory removal of a residual toner by moving forward and backward a toner removing machanism in accordance with the change in the friction force on the surface of a photosensitive drum thereby regulating the press contact force to a toner removing member. CONSTITUTION:If there is a residual toner in the edge 6' part facing a photosensitive layer 3, pressure 28 is transmitted by turning of a photosensitive drum 1 via removing member 6 and a leaf spring member 8 to a pressure member 9. When the force 27 nearly parallel with the tangent thereof is generated, a coil spring 10 is supported near the top end of a movable arm 14 and the balance is maintained by blocking force 30. If the residual toner decreases or is absent, the force 28 increases to exceed the force 30 and pushes the coil spring 10 thereby shifting the member 6 in the turning direction of the drum 10. The deflection of the material 8 is thus decreased and the press contact force 28' is attained but the friction force increases to the force 29' which presses the spring 10. The blocking force thereof shifts the contact position 32 in the edge 6' part to 33 and develops to the blocking force 30' which balances with the shifting rate 31 thereof.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a toner removal device for an electronic copying machine.

[Background of the invention]

In electronic copying equipment. Many inventions and ideas have been made and put into practical use regarding devices and methods for removing residual toner on a photosensitive drum after a toner image has been transferred. In particular, the elastic body is formed into a blade shape, the hardness and shape are set appropriately, and the edge portion of the blade is rubbed against the surface of the photosensitive drum to scrape off and remove the residual toner on the photosensitive drum. There are various methods for the above-mentioned removal, but the methods for supporting the blade can be roughly divided into two types: the method of supporting the blade is the method of supporting the blade before and after the rotation of the photosensitive drum with respect to the position where the scraping portion of the blade comes into pressure contact with the surface of the photosensitive drum. There are two ways to place that support point. First, we will discuss the case where a supporting point is placed before passing.

First, there are photosensitive drums in which a photosensitive material such as selenium is directly formed on the surface, and photosensitive drums in which the surface is covered with a thin layer of dielectric material, both of which have specular properties. When the edge of the blade is pressed against the photosensitive drum and the photosensitive drum is rotated, a strong frictional force is generated that pulls the edge of the blade in the direction of rotation of the photosensitive drum, causing the edge to move away from the surface of the photosensitive drum. Therefore, in order to keep the edge portion always in contact with the surface of the photosensitive drum, it is necessary to increase the thickness of the blade and apply pressure with a strong force. What has been described above is the case where there is no toner attached to the photosensitive drum. However, when toner adheres to the surface of the photosensitive drum, the frictional force changes, and extremely fine toner particles are thought to pass between the edge of the blade and the surface of the photosensitive drum. The particle size of the toner in the developer used for development is mostly 5.
Among these particles, the toner contains fine particles, which are thought to improve the lubrication between the surface of the photosensitive drum and the edges as the toner passes through them.

In other words, the above-mentioned condition always exists on the surface of the photosensitive drum used for copying, and the areas where there is no residual toner have a strong frictional force that lifts the edges, while the areas where there is residual toner scrape off the toner and press even harder. If there is a lot of toner deposited, but the image area is small, it will try to lift the edges and prevent the remaining toner from being scraped off.To eliminate this effect, the blade must be made stronger several times to effectively exert the removal action. It is necessary to do so. Therefore, as mentioned above, in order to strengthen the stiffness of the blade, it is necessary to have a thickness of about 5 mm and a hardness of about 60', and furthermore, the solenoid that presses the entire blade needs to be large and have a strong attractive force. Next, what if the support point is placed on the passing side? state This is because the above-mentioned blade is somewhat weak in removing toner, and in order to prevent this, a so-called wedge effect is created.
Since the blade is supported in a direction opposite to the rotating direction of the photosensitive drum, a different effect from that described above occurs. First, if there is no toner attached to the photosensitive drum surface, frictional force is generated between the photosensitive drum surface and the edge, as described above.
Furthermore, the frictional force increases, and there are cases where the blade is wound up and reversed. The effect of removing peaks from areas where toner adheres is outstanding.

However, because of the above-mentioned curling, the shape of the blade is limited, and therefore, it is impossible to use a blade that is too thin to utilize the wedge effect.

[Summary of the invention]

In particular, the present invention places the support part of the removal member in the same direction as the latter, but it has many excellent features in terms of performance, and makes it possible to control unnecessary pressure in non-image areas that conventionally occurs in edge areas. It is a device with many features. In the present invention, urethane or the like is used only for the part where the toner is scraped off, but a wide range of hardness and thickness can be specified.

[Embodiments of the invention]

The present invention will be described in detail below. FIG. 1 is a partially cutaway side view including essential parts of the present invention.

Note that since electronic copying devices are well known, their explanation will be omitted and only the toner removal device will be described.

The photosensitive drum 1 has a photosensitive layer 3 formed on a conductive drum 2, is supported by a shaft 4, and is rotated in the direction of the arrow during operation.

The removal member 6 made of an elastic material has a thickness of 0, 5, for example.
The edge portion 6' is fixed to one end side of a strip-shaped leaf spring material 8 as shown in the figure so that the edge portion 6' is in contact with the surface of the photosensitive layer 30 with a predetermined pressure. Pressure is applied by applying deflection.

The other end of the leaf spring material 8 is firmly attached to the groove of the pressure member 9, and the leaf spring material 8 and the pressure member 9 are provided with rollers 11 and 11, respectively. It is held between rollers 12 and 12, allowing it to move forward and backward in the direction of the arrow. The movable arm 14 is rotatably supported by a support pin 15 and rotates between stoppers 18 and 19. Movable arm 1
4 and the plunger 21 of the solenoid coil 20 are connected to each other by tensioning a coil spring 24 at the holes 16 and 21'. The pin 23 and the hole 17 are connected by the tension of a coil spring 25, and when the solenoid coil 22 is de-energized, the contracting force of the coil spring 25 causes the movable arm 14 to come into contact with the stopper 19 as shown by the double broken line. energized. Therefore, since the movable arm 14 and the pressure member 9 are connected via the coil spring 10, the edge 6' portion is pulled away from the surface of the photosensitive layer 3, although not shown. However, as shown in the figure, when the coil 22 of the solenoid 20 is energized during operation, the plunger 21 is attracted, and the movable arm 14 is moved to the stopper 1.
8 through a coil spring 24.

Therefore, as shown in the figure, the pressure member 9 is biased via the coil spring 10 so as to come into contact with the strike point (-13).
Applying deflection from the side.

The edge 6' portion is uniformly pressed against the surface of the photosensitive layer 30. That is, this position is a position where residual toner is present on the surface of the photosensitive layer and the pressure required to remove the remaining toner is maintained. Of course, the relationship between the above-mentioned pressure contact force and the coil spring 10 will be described next. 8
Figure 2 is a vector diagram of the force action. Pressure 28 is applied when there is residual toner on the edge 6' facing the photosensitive layer 3.

Due to the rotation of the photosensitive drum 1, the rotation of the photosensitive drum 1 is transmitted to the pressing member 9 via the removing member 6 plate and the removing member 8. That is, a force 27 nearly parallel to the tangent line is generated on the pressure member 9. The coil spring 10 is supported near the tip of the movable arm 14 and counterbalances the force 27 with a blocking force 30. There is little toner remaining on the surface of Photosensitive 13.

If the force 28 is not present, the force 28 increases and becomes larger than the blocking force 30, pushing the coil spring 10 and eventually deflecting the removal member 6 in the direction of rotation of the photosensitive drum 1, thereby preventing the leaf spring material 8 from deflecting. As the contact force decreases, the pressure contact force 28' increases, but the friction force increases and becomes a force 29' that pushes the coil spring 10, counteracting that force. The stopping force of the coil spring 10 is such that the removing member 6
The abutment position 32 of the 'portion' is displaced to 33, and the displacement amount 31 is compressed, resulting in a balanced blocking force 30'. As described above, the pressure force for pressing the removal member 6 against the photosensitive layer 3 of the photosensitive drum 1 is adjusted by deflecting the removal member 6 in response to changes in the frictional force depending on the presence or absence of residual toner on the photosensitive layer 3. Since the pressure contact force between the layer 3 and the removal member 6 can be adjusted, unreasonable sliding force is not generated, and therefore, there is no change in load due to sliding, and residual toner can be removed effectively. . An elastic conductor 7 is attached to the non-rubbing side of the removing member 6, and a power source 2 is connected to the elastic conductor 7.
From 6, it is also appropriate to apply a potential of the same polarity as the toner and electrostatically discharge the toner after removal. This is because it is inappropriate. Conventionally, when using a blade, a predetermined thickness, hardness, and shape are specified in order to take advantage of its characteristics.

In the present invention, if it can be supported by the leaf spring material 8.

The plate spring material 8 may be coated, and the hardness can be determined depending on the thickness of the removed member, and the range can be expanded. Furthermore, 14 movable arms? The actuation is not limited to a solenoid, but may be performed by a cam mechanism using a small motor or the like. The relationship between the photosensitive +t'i 3 and the pressure contact force with the removal member 6 is primarily concerned with the adjustment of the pressure contact force, and the mechanism thereof is not limited to the detailed description of the present invention.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view including the main parts, and FIG. 2 is a vector diagram. 1... Photosensitive drum, 2... Conductive drum, 3... Photosensitive layer. 4... Shaft, 5... Toner removal device, 6... Removal member, 6'... Edge portion, 7... Elastic conductor, 8...
- Plate spring material, 9... Pressure member, 10... Coil spring, 11... Roller. 12...Colo, 13...Stopper, 14...Movable arm. 15...Support pin %16...hole, 17...hole, 1
8...stoppani, 19...stopper 120...
·solenoid. 21... Plunger, 21'... Hole, 22...
coil.

Claims (1)

[Claims] 1. In a device for removing toner remaining on the surface of a photosensitive drum of an electronic copying device, one end of a plate-shaped spring member that can support a toner removal member made of an elastic material on the surface of the photosensitive drum in a press-contact manner. A pressure member is attached to the other end of the plate-shaped spring material to form a toner removal mechanism, and a toner removal member is pressed against the surface of the photosensitive drum, and the pressure contact portion rotates the surface of the photosensitive drum. The toner removing mechanism is disposed on the tangential direction of the passage so as to be movable back and forth, and the toner removing mechanism is moved in response to changes in the frictional force on the surface of the photosensitive drum that occurs at the pressure contact portion as the photosensitive drum rotates. 1. A toner removal device having a pressure contact force adjustment device, characterized in that the pressure contact force of the toner removal member on the surface of the photosensitive drum can be adjusted by moving the toner removal member forward and backward.