JPH0131192B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for an electrophotographic apparatus.

The transfer type electrophotographic copying device has a cleaning blade whose tip is pressed into contact with the surface of the photoreceptor, and a casing that covers the cleaning blade. In a cleaning device that is formed with an opening large enough to not prevent pressure contact with the body, the cleaning blade cleans the photoreceptor and scatters the scraped residual toner to the outside of the casing through the opening. Conventionally, the following techniques have been known as means for recovering the waste without removing it, but each has its own drawbacks.

The prior art and its drawbacks are listed below.

1 This is a technique disclosed in Japanese Patent Application Laid-Open No. 54-85037, and its outline is that a plate-shaped sealing material is provided obliquely to the falling direction of residual toner scraped off by a cleaning blade, and a plate-shaped sealing material is provided on this sealing material. The toner accumulated in the toner is guided along the slope to a predetermined collection site and collected by applying impact or vibration to the sealing material.

In this technology, as mentioned above, the sealing material also has the function of a toner guide plate,
Although toner is prevented from scattering to the outside of the casing, toner tends to accumulate in a short period of time and is not easily moved to the collection section. For this purpose, shocks and vibrations are applied, and of course a device for applying shocks and vibrations is required.
Furthermore, there is a high risk that the sealing material will break or be damaged due to impact or vibration, and if it breaks or breaks, toner will fall or scatter, requiring the apparatus to be stopped and replaced.

2 This is a technology disclosed in Japanese Patent Application Laid-open No. 52-88032, and its outline is that a roller serving as a sealing material is provided on the photoconductor at a position in front of the cleaning blade (uncleaned part), and the speed is lower than the speed of the photoconductor. It rotates at high speed to prevent toner from falling outside the casing and to collect it.

The disadvantage of this technique is that the equipment is complex and costs increase accordingly.

The present invention has been made in view of the above-mentioned problems in the prior art, and provides a cleaning device for an electrophotographic device that has a simple configuration and can prevent toner from falling or scattering outside a casing at low cost. The purpose is to

The present invention will be explained in detail below.

The present invention includes a cleaning blade whose tip is pressed into contact with the surface of a photoreceptor of a transfer type electrophotographic copying device, and a casing that covers the cleaning blade. A cleaning device is provided with an opening large enough to prevent the blade from coming into pressure contact with the photoreceptor, and a plate-shaped sealing material for preventing toner scattering is provided at the lower end of the opening, One end of this sealing material lightly contacts the surface of the photoreceptor or leaves a slight gap therebetween, the other end is substantially integrated with the casing, and furthermore, a horizontal line is drawn from the tip of this sealing material toward the inside of the casing. The angle between the sealing material and the vertical surface of the sealing material is set to be ≧90°.

In FIG. 1, reference numeral 1 indicates a photoreceptor drum of a transfer type electrophotographic apparatus, and a photoreceptor layer is formed on the circumferential surface of the drum. , exposure, development, transfer, transfer material separation, and other process sections are provided. A cleaning device according to the present invention, indicated by reference numeral 2, is located behind the transfer material separation process section in the rotational direction of the photosensitive drum 1.

A cleaning blade 3 is held between a holder 4 and a support member 5 by tightening a screw 6. As shown in FIG. Further, the screw 6 may be a stepped screw so that it can freely move in the front-rear direction (direction perpendicular to the axis of the drum). The cleaning blade 3 rotates around a rotating shaft B that supports the support member 5, and its tip is pressed against the surface of the photoreceptor by a pressure mechanism (not shown).

A casing 7 is box-shaped and covers the cleaning blade 3 and its accessories, and has an opening 8 in a portion facing the photoreceptor drum 1 .

By the way, the portion of the casing 7 located below the cleaning blade 3 has a helical coil 9
It is curved according to the curvature of , and together with the helical coil 9 constitutes a toner collection section 10 . An end 7a of the casing 7 near the toner collecting section 10 and corresponding to the lower end of the opening 8.
is located with a slight gap from the photoreceptor drum 1. Although this gap has a necessary amount to allow rotation of the photoreceptor drum 1, residual toner scraped off by the cleaning blade 3 scatters to the outside through this gap. Therefore,
The sealing material 11 according to the present invention is provided to close this gap.

The sealing material 11 is a plate-shaped member having a length in the longitudinal direction of the axis of the photoreceptor drum 1. Its lower end is attached to the casing 7, and its upper end lightly contacts or slightly touches the circumferential surface of the photoreceptor drum. It is set to leave a gap.

Here, the meaning of "lightly contacting" or "leaving a slight gap" is to allow the residual toner on the photoreceptor drum to pass through, and this condition was set because the photoreceptor drum is rotating in the direction of the arrow. The residual toner adhering to the circumferential surface of the body drum 1 must first pass through the sealing material 11 and reach the inside of the casing 7, and then be scraped off by the cleaning blade 3. However, if the toner is scraped by the sealing material 11 before reaching the cleaning blade 3, there is no point in providing the cleaning blade 3, and the scraped toner is removed from the casing 7.
This is because it will scatter outside.

Furthermore, the following conditions are required when setting the sealing material 11. As shown in FIG.
The angle θ formed with the vertical plane is set so that θ≧90°.

With this configuration, toner still adhering to the circumferential surface of the photoreceptor after the transfer material separation step is scraped off by the cleaning blade 3 after passing through the sealing material 11 portion. The photoreceptor thus cleaned is used again. On the other hand, although the toner naturally falls, since the sealing material 11 is set vertically or at an angle close to that, as described above, the toner does not accumulate thereon and is received by the collecting section 10.

The toner that has naturally fallen into the collection unit 10 in this way is discharged to the outside of the casing 7 by the helical coil 9 and is collected or reused.

Note that during the above-mentioned natural fall, some of the toner scatters inside the casing 7 and attempts to scatter to the outside of the casing 7, but is blocked by the sealing material 11, and the toner does not fall to the outside of the casing 7. , no scattering occurs.

Suitable materials for the sealing material 11 include resin films such as Mylar and elastic materials such as polyurethane. Although the thickness is not particularly limited, it is thought that there is a value that is more suitable for the setting position of the sealing material 11 during implementation. For example, the closer the position is to the horizontal line JJ passing through the rotation center O of the photoreceptor drum 1, the more
As shown in FIG. 3, the toner T is applied to the sealing material 1
Since it falls directly onto the end face of 1, it tends to accumulate. Therefore, when setting it at a position close to the horizontal line JJ, a thinner one is preferable. On the contrary, the horizontal line J-J
It may be made thicker when it is set at a position away from. In addition, the thickness is determined by taking into consideration the relationship with the material. Note that the thicker the film such as Mylar, the harder it becomes and the more likely it is to damage the surface of the photoreceptor drum 1, so it is generally best to set the film thickness to 30 to 500 μm (preferably 40 to 200 μm). Since it is difficult to stand upright as a material, a suitable thickness is required, and the value should be varied depending on the hardness of the rubber.

When adopting a configuration in which the tip of the sealing material 11 lightly contacts the photoreceptor drum 1, it is quite difficult to make the contact uniformly across the entire width.As a countermeasure, as shown in FIG. Make incisions 12 in several places at intervals. By doing so, it is possible to curve each cut section and bring it into uniform contact with the photoreceptor drum 1.

According to the present invention, since the toner scraped off by the cleaning blade does not accumulate on the sealing material, the scraped toner can be easily collected and discharged, and unlike the conventional technology, Since no additional mechanism for applying vibrations or shocks is required, the structure of the device can be made simple and compact, which is advantageous because it can be done at low cost.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional view of a cleaning section illustrating an example of a cleaning device according to the present invention, Fig. 2 is an enlarged view illustrating the state in which the sealing material is attached in the same figure as above, and Fig. 3 is an enlarged view of the tip of the sealing material. , FIG. 4 is a plan view of the sealing material with the cut. 3...Cleaning blade, 7...Casing,
8...Opening, 11...Sealing material.

Claims (1)

[Scope of Claims] 1. A transfer type electrophotographic device has a cleaning blade whose tip is pressed against the surface of a photoreceptor, and a casing that covers the cleaning blade, and the casing includes: In the cleaning device, an opening is formed in a size that does not prevent the cleaning blade from coming into pressure contact with the photoreceptor, and a plate-shaped sealing material for preventing toner scattering is provided at the lower end of the opening. One end of this sealing material lightly contacts the surface of the photoreceptor or leaves a slight gap therebetween, the other end is substantially integrated with the casing, and the sealing material extends from the tip toward the inside of the casing. 1. A cleaning device for an electrophotographic apparatus, characterized in that the angle between the vertical line of the sealing material and the vertical surface of the sealing material is set to be ≧90°.