JPS5986078A - Cleaning method of electrostatic recording device - Google Patents

Abstract

PURPOSE:To reduce the amount of toner sticking to a fur brush and to improve cleaning characteristics by making the polarity of a pre-cleaning corona charger coincident with the polarity of a latent image. CONSTITUTION:The polarity of the pre-cleaning corona charger 2 is made coincident with the polarity of the latent image on a photosensitive drum 1, i.e. made positive, etc.; the amount of toner sticking to the fur brush is reduced and a sticking toner removing device is unnecessary. Further, staining due to the toner sticking to the brush 4 is less, so as abrupt drop of the cleaning characteristics due to staining is prevented and the cleaning characteristics are improved.

Description

[Detailed description of the invention] Technique: j field The present invention relates to a method for cleaning an electrostatic recording device.

Prior Art In static 1m ML recording devices, static elimination of photoreceptors and toner has been proposed as a method of removing static electricity before cleaning.11. [I] For example, light is irradiated to completely lower the potential of the photoreceptor, and then alternating current corona is applied, but pre-cleaning corona charge (hereinafter referred to as 1)
When using a "CC", it is necessary to use suction to remove the toner cleaned with the fur brush from the fur brush, which requires a vacuum device, bias roller, etc., which increases the size and cost of the device. , there are disadvantages such as loud noise.

Purpose The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and in particular, to reduce the amount of dirt on the brush by using electric potential in Pcc, thereby removing toner that has accumulated on the brush. Special measures such as vacuum equipment and bias rollers are made immobile to make the equipment more compact and inexpensive, as well as to reduce noise. 4. E objectives were to obtain cleaning performance and to reduce the ``duration'' of the fade.

Embodiment FIG. 1 is a diagram for explaining an embodiment of the present invention, and the figure shows the cleaning section of a military aircraft. ,
3 is a seal, 4 is a fur brush, 5 is a cleaning blade, 6 is a blade holder, 7 is a step screw, 8 is a support plate, 9 is a discharge coil, 1° is a flicker, and the photosensitive drum 1 is moved in the direction of the arrow. For example, the image is rotated at a speed of 210 mm/sec (as is well known), and is transferred onto recording paper in a transfer section (not shown). Toner remaining without being transferred is applied with a voltage of 50 .mu.A in a pre-cleaning charge (hereinafter referred to as FCC) 2, and both the toner photoreceptor and the toner photoreceptor are charged to . Next, a part of the toner that has passed through the /-ru 3 is cleaned by a conductive fur brush 4 (resistance ~10Ω box, outer diameter 20mm, rotation speed 1-1-90 rpm photoconductor). be done. The toner not removed by the fur brush 4 is then completely cleaned by a blade 5 (blade hardness: 78 degrees, thickness: 3 mm, free flute length: 15 mm, set angle with the drum: 78 degrees).

This cleaning blade 5 is adhered to a boulder 6, and the holder 6 is rotatably supported at one point in the center of a support plate 8 by a stepped screw 7. -1: Support &8
is fixed at a rotation center (not shown) and pressurized by a spring or the like. The toner removed by the fur brush 4 and cleaning blade 5 as described above is discharged forward or backward (backward in the illustrated example) by the discharge coil 9, and is discarded or reused (in the illustrated example, it is used). When test copying was carried out using a copying machine having a cleaning unit configured as described above, cleaning failures occurred after 20,000 copies were made without PCC, but in the case of the embodiment of the present invention in which 50 μA of PCC was applied, 7 copies were made.
No cleaning defects occurred even after 0,000 copies were made. 1) If CC is not applied, the pressure applied to the blade 4 for cleaning should be L45 to 50.
! 7cm2 was required, but when applying PCC of 5Q/zA, it can be reduced to 35g/α2-, and the amount of wear at the blade tip is also 200g/α2- according to the embodiment of the present invention.
5 .mu.m for 00 sheets of copying, whereas in the conventional technology that does not apply PCC, it is as large as 30 .mu.m. According to the present invention, it has been demonstrated that the blade's durability can be improved and obtained.

Figure 2 shows the performance of blade cleaning. As is clear from the figure, the cleaning performance deteriorates with a certain amount of input toner, and it is understood that there is a limit to the amount of toner that can be cleaned by the blade. This cleaning performance varies depending on other conditions (main transfer), blade wear and flame, etc., but in order to obtain good cleaning performance, the amount of toner input to the blade must be 01m9/Cm2.
It needs to be below, but the maximum for normal input toner is 0
．． 2 ny /-cln Since it is in the 2nd place, it is necessary to remove about half of the toner after transfer.

Figure 3 is a diagram showing the cleaning performance of the brush, where the horizontal axis shows the PCC current and the vertical axis shows the brush cleaning performance.
This figure shows the amount of toner contained in the brush stain caused by copying 00 sheets. As shown in this Figure 3, PCC
When θ is applied, when the brush is YlrL, it exhibits extremely good cleaning performance, but when the brush becomes dirty, the cleaning performance decreases rapidly. On the other hand, when I) CC ■ is applied, the brush becomes less dirty after 200 copies and the cleaning performance does not deteriorate at all. I know you'll be disappointed. It should be noted that the cleaning performance of the brush to which J)CC(g) was applied was not sufficient to clean a blank, and was at a level that caused image defects. However, by using it in conjunction with blade cleaning, it is possible to sufficiently reduce leaning.On the other hand, if plan cleaning is too high, the load on the blade and tram will increase, resulting in damage to both the drum and blade. This results in a decrease in +t'l durability.

In other words, the present invention further improves cleaning performance and durability by using a bra/brade in combination, and also has the advantage that suction and bias rollers are not required because there is less dirt on the plan. be.

In addition, although an example (1 example) using a conductive brush has been described above, the present invention is not limited to the above-mentioned example. It is also possible to use - For example, as a result of testing using a brush made of a 130% blend of 30 denier rayon fiber and conductive fiber as a fur brush, it was found that the cleaning properties were sufficient for up to 50,000 copies. In order to carry out the toner IJ cycle, it was thought that it would be preferable to make the toner polarity common to the photoreceptor charge, but as in the present invention, it is possible to recycle the toner by giving it a charge of the same polarity. However, good images could be obtained without any side effects such as background smearing.

Effects As is clear from the above explanation, according to the present invention, (1) the brush always maintains a constant cleaning efficiency, so it is possible to obtain good IJ-ning performance by combining it with the blade. can.

(2) Extremely high performance is required when using a brush or blade alone, but by using these together, the performance conditions are relaxed, and stable and highly reliable cleaning performance can therefore be obtained.

(3) When PCC is used, even if the plano gets dirty, it will not stain the drum because it has the same polarity as the photoreceptor.

There are advantages such as

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining one embodiment of the present invention, which shows the cleaning section of a copying machine, Fig. 2 shows the blade cleaning performance, and Fig. 3 shows the cleaning of the brush. It is a figure showing performance. 1 photosensitive drum, 2 pre-cleaning charge, 3
Knoll, 4...far plan, 5 cleaning blade, 6 blade holder. 11th λ 2nd [ 3rd

Claims (1)

[Claims] Cleaning of an electrostatic recording device in which a pre-cleaning corona charge is performed as a pre-cleaning treatment, characterized in that the polarity of the pre-cleaning corona charge is the same as that of an electrostatic latent image on a photoreceptor. method.