JPS58132778A - Cleaning device of drum - Google Patents

Abstract

PURPOSE:To obtain a good cleaning effect, by operating large press-contact force by a cleaning blade in accordance with a toner, prescribing a ratio of the free length against thickness of the cleaning blade, within a prescribed range, and constituting so that the tip of the blade does not escape. CONSTITUTION:When a cleaning blade 2 is press-moved in the direction separated from a photoreceptor drum 1 by putting external force, an arm 3 and an L- shaped piece 4 are turned centering around the pivotally supported part, respectively, and simultaneously, a spring 7 and a leg opening spring 9 are deformed in the direction for storing energy, respectively, and the larger the deforming quantity becomes, the larger restoring force is generated, and force for pressing the tip of the cleaning blade 2 strongly against the surface of the photoreceptor drum 1 operates strongly. The more a toner T press-moves the cleaning blade 2, the stronger force of each spring operates, and the cleaning blade 2 is made to press-contact with the photoreceptor drum 1 more strongly, therefore, even if a large quantity of toner T comes in, it can be scraped exactly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drum cleaning device used in an image recording apparatus.

In an image recording device that uses toner as a developer, residual toner still exists on the circumferential surface of the image bearing drum, such as a photoreceptor drum, that carries an image even after the existing recording process has been completed, so it is difficult to carry out the next new recording process. Before starting, this 7L must be removed.

If residual toner is left unattended, it will impair uniform charging in the next copying process, prevent correct exposure of the original image, and also cause residual toner to adhere to the transfer paper and smudge the image. be.

Conventionally, as a cleaning means for removing the residual toner, a blade is installed in a trailing direction on the photoreceptor, which is the surface to be cleaned, and according to the relative movement between the blade and the photoreceptor, However, with this method, if a large amount of toner gets into the tip of the blade, a force will be applied to the tip of the blade in the direction of pulling the blade away from the photoreceptor. . Moreover, since the tip of the blade escapes from the surface of the photoreceptor, there is a drawback that the ability to remove toner is significantly reduced. If the cleaning performance deteriorates in this way, it will have a very bad effect on the recorded image as described above, and the copy quality will deteriorate.The present invention provides a drum cleaning device that can eliminate the drawbacks of the above-mentioned prior art. The present invention will be described in detail below.

The drum cleaning device according to the present invention includes a cleaning blade that is installed in the trailing direction and whose tip end is in contact with the surface to be cleaned, and a support member that supports the proximal end surface of the cleaning blade. A cleaning blade is provided between the stationary member and the support member, and the tip of the cleaning blade is elastically pressed against the surface to be cleaned.
It has an elastic means that acts to press the cleaning blade, and the ratio of the free length to the thickness of the cleaning blade is 1 to 5.
It is characterized by being set to .

In FIG. 1, reference numeral 1 indicates a photosensitive drum, and on its circumferential surface are set various process sections, such as those well known in electrophotographic devices, such as charging, exposure, development/transfer, and charge removal. ing. However, since these process units are not particularly necessary for the explanation of the heather, illustration thereof is omitted.

The illustrated portion is located on the photosensitive drum at an intermediate position between the transfer process section and the static elimination process section, and the cleaning device according to the present invention is installed in this section.

Reference numeral 2 denotes a cleaning blade, which is made of an elastic member such as hard rubber or a metal plate covered with rubber, and, like the photosensitive drum 1, has a thin plate shape with a length extending in the direction penetrating the plane of the paper. ing.

The cleaning blade 20 is fixed to the free end of the arm 3 at its base end. Also, the base end of the arm 3 has a 5-shaped piece 4.
A pin 5 having an axial direction penetrating the paper surface at one end 4a.
It is centrally located. Furthermore, the bent portion of this 5-shaped piece 4 is integrally supported with a fixed member (not shown) and pivoted by a pin 6 parallel to the pin 5, and one end of an extensible spring 7 is attached to the other end 4b. is stopped. A stationary member 8 is attached to the other end of the spring 7. In addition, one end 4 of the 5-character piece 4
There is a leg spring 9 between a and the arm 3.
Then, due to the restoring force of the spring 7 and the leg spreader spring 9, the tip of the cleaning blade 2 is pressed against the photosensitive drum 1 with an appropriate pressing force suitable for cleaning within a range that does not deform the cleaning blade. It's cool. At this time, the attitude of the cleaning blade 2 is inclined in the trailing direction with respect to the photosensitive drum l rotating in the direction of the arrow, and the length of the free end is l! with respect to its thickness t! D. It is set to have a ratio of 1 to 5. Due to this, the length l is shorter than that of the conventional one, and it has a so-called stiff characteristic.

As mentioned above, the arm 3 is pivotally supported by the HL piece 4.
Since the cross section 4 is pivotally supported by the pin 6, if an external force is applied to move the cleaning blade 2 away from the optical drum 1.
When pushed in the direction of H1, the arms 3 and 5-shaped pieces 4 each rotate around their pivot points Ic, and as they are pushed, the springs 7 and leg springs 19 are deformed in the direction of storing energy.
As the amount of deformation increases, a larger restoring force is generated, and a stronger force is exerted to press the tip of the cleaning blade 2 against the surface of the photoreceptor drum 1. The strength relationship of each spring is determined so that the leg spring 9 is deformed and then the spring 7 is deformed.

As the photoreceptor drum l rotates in the direction of the arrow, residual toner T arrives at the tip of the cleaning blade 2.
Furthermore, considering the situation when trying to pass through the core, the more the toner T tries to push the cleaning blade 2, the stronger the force of each spring acts as described above, pushing the cleaning blade 2 further. Since the cleaning blade 2 is brought into strong pressure contact with the photoconductor drum 1, even if a large amount of toner T enters, it can be scraped off reliably.In this way, the pressure contact force of the cleaning blade 2, which is maintained by the spring, is strong. In combination with this structure, the toner T acts effectively in accordance with the amount of toner T, and exhibits a good cleaning effect.

If the ratio of length l to thickness t is too large, the blade will bend and bend when there is a large amount of residual toner, as in the prior art, and a sufficient cleaning effect cannot be achieved. On the other hand, if the ratio is too small, the tip of the cleaning blade will be uneven in the axial direction of the photosensitive drum 10, and the photosensitive surface will not be cleaned uniformly, resulting in poor cleaning, which is undesirable.

In consideration of the above, it was concluded that the most appropriate dimensional ratio of the leaning blade is a ratio of length l to thickness t in the range of 1 to 5, as described above.

In order to achieve even more effective cleaning performance, it is recommended to provide a pre-treatment process as shown in FIG. This is done by doing this.

The brush 10 is made of rayon, acrylic, conductive fibers, etc., and is rotated in a direction opposite to the moving direction of the photoreceptor drum 1 to remove residual toner.
This reduces the cleaning load by the cleaning blade 2, which is a subsequent process.

The toner released from the photosensitive drum surface by the brush 10 or the cleaning blade 2 falls under its own weight and is collected by a toner discharge member (for example, a screw conveyor) 12 in the casing 1 into a toner tank (not shown). be done.

In this way, in the present invention, a large pressure contact force is applied to the cleaning blade corresponding to the amount of toner, especially the amount of toner that tries to push up the tip of the cleaning blade, and the ratio of the free length to the thickness of the cleaning blade is set within a predetermined range. Since the tip of the blade does not escape by defining the inside, a good leaning effect can be obtained.

Note that the cleaning device according to the present invention can also be applied to cleaning the surface of the thermal foot roller.
In that case, a heat-resistant grade material should be used.

[Brief explanation of the drawing]

FIG. 1 is a front view of the main parts of the cleaning device according to the present invention, and FIG. 2... Cleaning blade, 3... Arm (as an example of a support member), 4... (as elastic means)
L-shaped piece, 7... Spring (as elastic means), 9...
Spreading spring (as an elastic means). heather 4 selling bolt

Claims (1)

[Scope of Claims] A cleaning device that removes toner by applying a blade to the peripheral surface of a drum, comprising: a cleaning blade that is set in a trailing direction and has a tip thereof in contact with a surface to be cleaned; A support member that supports the base end of the cleaning blade, and an elastic member that is provided between the stationary part and the support member and acts to elastically press the tip of the cleaning blade against the surface to be cleaned. A cleaning device for an image bearing drum, characterized in that the cleaning blade has a free length to thickness ratio of 1 to 5.