JPS58205178A - Blade cleaning device - Google Patents

Abstract

PURPOSE:To absorb the expansion and strain of a blade due to a temperature rise at the circumference of a cleaning device, and to prevent the generation of an oscillation noise by forming slits at the tip part of the blade member at right angles to the shaft of an image carrier. CONSTITUTION:The slipts 10a and 10a perpendicular to the shaft of a photosensitive drum 1 are made in the blade 10 at a distance of length l1 from both ends of the blade 10, and their length are set equal to the length l2 of projection of the blade 10. The slit gap delta of the slit 10a is large enough to absorb the strain of the blade 10 due to the expansion in the shaft direction of the photosensitive drum. Consequently, the strain and expansion of the tip part of the blade 10, i.e. variation DELTAU at the center part and variation DELTAL at end parts are eliminated to realize uniform press contacting in the shaft direction of the photosensitive drum. Thus, the oscillation of the blade in case of a temperature rise is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a blade cleaning device, and more particularly to a toner image carrier that is moved with residual toner attached to its surface, such as an electrophotographic photoreceptor in a toner image transfer type electrophotographic copying machine. The present invention relates to a blade cleaning device having a cleaning blade that removes residual toner from the surface of a toner image carrier by bringing its tip into pressure contact with the surface of a drum or the like.

Prior Art Conventionally, the blade cleaning equipment in this building was shown in Figure 1 (-
1, an elastic cleaning blade fB held in a metal holder made of aluminum or iron alloy, etc.
l to a toner image carrier, such as an electrophotographic photoreceptor,
The toner remaining on the surface was removed.

However, when the environmental temperature around the blade cleaning device rises during the copying operation, there is a drawback that vibration noise of the blade (B) is generated. In order to eliminate these drawbacks, we tried changing the material and contact force of the blade fB), and found that there was no vibration noise at first, but when the environmental temperature rose, the vibration noise occurred again. was not achieved. Therefore, we thought that the vibration noise was caused by a change in the shape of the blade (B) due to changes in the environmental temperature, and when we investigated this, we confirmed the following.

■ Blade (metal holder of Bl) (The part that is held in the river has a small degree of freedom and expands according to the thermal expansion of the river, but the part that presses against the photoreceptor in town is It expands with a coefficient of thermal expansion specific to the material it is made from.Furthermore, the material that makes up the blade (Bl) generally has a higher coefficient of thermal expansion than the material that makes up the metal holder, so the blade CB+ Deform into a fan shape as shown by the dotted line on the right side of the center.

■ As shown in Figure 1 (bl), as the length of the blade (B) increases, Ll increases. is to increase.

Therefore, from ■■, it was found that the pressure contact of the blade (Bl) against the photoreceptor became uneven, and vibration noise was generated.

From these results, it was concluded that the conventional drawbacks can be overcome by suppressing the deformation of the blade fBl due to thermal expansion.

OBJECTS The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a blade cleaning device that can effectively remove blade vibration noise with a simple configuration.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a blade cleaning device equipped with a blade member for removing residual toner adhering to the surface of a toner image carrier. The blade cleaning device is characterized in that a slit is formed in a direction perpendicular to the blade.

Embodiment FIG. 2 shows an embodiment of the blade cleaning device according to the present invention, which is applied to a toner image transfer type electrophotographic double trout machine.

The photosensitive drum (1) is rotationally driven in the direction of arrow fa),
Residual toner that was not transferred to the transfer paper in the previous process adheres to the surface leading to this cleaning device.

This cleaning device generally consists of an external casing (2)
, cleaning blade (1o), and toner seal plate (
23), and the residual toner scraped off from the surface of the photoreceptor drum (1) by the blade (1o) is removed by rotation of the toner conveying coil (22) in the direction of arrow b1 in FIG. 2 (not shown). It is returned to the developing device.

The external casing (2) is installed on a frame (not shown) at a certain distance from the photosensitive drum (1).

The blade holding member (5) is installed in the outer casing (2) and is rotatable about a pin (3) fixed to the side wall of the outer casing (2) as a fulcrum. The cleaning blade (]0) is attached to the step part () of the blade holder (11).
]2) is adhesively bonded. The holder (11) is swingably mounted on the blade holding member (5) by screwing one support screw (3) into the holding member (5) at the center. That is, the blade (10) and the holder (11) are swingable on the holding member (5) using the supporting member 13) as a fulcrum. This is the blade (1
This is to uniformly press the tip of the drum t(1) into the middle direction of the surface of the photoreceptor drum t(1). Ma? .

A coil spring (7) is stretched between the end of the bolt (6) protruding from the blade holding member (5) to the right in Fig. 1 and the pin (4) fixed to the outer casing (2). ing. The arrow (di) due to this coil spring (7)
The blade holding member (5) is moved by the pin (3) due to the tensile force in the force direction.
) as a fulcrum and is urged in the direction of arrow (C1), and the tip of the blade (10) is pressed against the surface of the photoreceptor drum (11). In this case, the cleaning device is of the reverse blade type, and the blade ( The tip of the toner collection casing (20) is bent upward slightly and is pressed against the surface of the photoreceptor drum (1) at a contact angle (θ) of 60° to 90°. Toner collection groove (21
), and a toner seal plate (23) made of polyester film is installed on the front face thereof, and the tip of the toner seal plate (23) is in light pressure contact with the surface of the photoreceptor drum (1). The toner collecting groove (2I) is provided across the middle of the photosensitive drum iI), and the toner conveying coil (22) is rotatably installed inside the groove.

The scraped-off residual toner falls into the toner collection groove (21) along the inner surface of the toner seal plate (23), as shown by arrow f.
The toner is conveyed to the developing device through a toner conveying pipe (not shown) by a toner conveying coil (22) which is rotationally driven in the direction b), and is provided for reuse.

In the configuration 1- above, the toner remaining on the surface of the photosensitive drum (1) which is rotationally driven in the direction of the arrow (-) and has completed the development and transfer steps is scraped off by the tip of the blade (10).

FIG. 3 shows the main parts of the blade cleaning device.

In the figure, the blade (10') includes a photoreceptor drum (
1) A slit (lQa) at a position perpendicular to the axial direction and spaced a length tl from both ends of the blade (10).

(10a) is provided, and this slit (10a)
.

(10 m) is the protruding length t of the blade (10)
It is set the same as 2). Also slit (10a)
.

(The slit gap (δ) of the IO is set to be a gap sufficient to absorb distortion caused by expansion of the blade (10) in the axial direction of the photosensitive drum (1).

Here, the conditions and results of the experiment conducted using the blade cleaning device according to the present invention are as follows.

■Blade thickness: 5+mn Length (L): 280 wn (Photoconductor drum axial direction) Projection length 41:19 column Hardness -73 degrees (JISA) Pressure contact angle (θ) Near 7° Edge pressure contact crab 5.2r / Cabinet ■ Slit length 4): 30 m + n Gap (δ) - 05 songs ■ Holder ■ Environmental temperature at the start of the experiment Under conditions of 25°C or higher, the inventor's experiment number (Z, slit (10a), (In case A, it has been confirmed that vibration noise of the blade (10) is generated when the environmental temperature exceeds 40°C) or the slit (10a) is not provided as in the present invention. , (10a), no vibration noise was generated even when the environmental temperature exceeded 45°C.

Furthermore, even when a long-term running test was conducted, no vibration noise was generated from the blade (10). Furthermore, since the vibration of the blade (10) could be suppressed, wear on the tip of the blade (1o) due to vibration was also improved, and it was confirmed that good leaning performance was maintained over a long period of time.

This is because the strain caused by expansion of the blade (10) mainly in the axial direction of the photoreceptor drum (1) due to the rise in environmental temperature is absorbed by the slit gap (δ) between the slits (101) and (10a). sleeve) (10a
).

Since the axial expansion in each part of the blade (1o) divided by (]Oa) is reduced, the blade (]O)
Distortion and expansion of the tip end are eliminated, and the photoreceptor drum (1)
This is because the pressure is applied uniformly in the axial direction.

In this example, the slit gap (δ) was set to 0.5 mm, but in consideration of the cleanability of the slits (]Oa) and (10a), a range of 0.5 mn to 1.0+n is appropriate.

That is, if the slit gap (δ) is smaller than 0.5 m, the effect of absorbing strain due to thermal expansion of the blade (]0) will be reduced, and if it is larger than 1.0 m, the slit gap (δ) will not be blocked. If the amount of toner is not enough, some toner remains.

On the other hand, the material of the blade (10) is not limited to polyurethane rubber, and a wide variety of elastic rubber materials such as silicone rubber, fluorine rubber, acrylic rubber, chloroprene rubber, and neoprene rubber can be used. In addition, the blade (10
) is preferably selected to have a hardness within the range of 60 degrees to 90 degrees (JISA).

Effects As is clear from the above explanation, the present invention has a slit formed at the tip of the blade member in a direction perpendicular to the axial direction of the toner image carrier, so that expansion and distortion of the blade due to an increase in the environmental temperature around the blade cleaning device can be effectively prevented. Since the blade can be brought into even pressure contact with the toner image carrier, no vibration noise is generated. Moreover,
Since blade vibration can be prevented, good leaning performance can be maintained for a long period of time.

[Brief explanation of the drawing]

Figure 1 (-1 is a diagram showing a problem with a conventional elastic cleaning blade, Figure 1 fbl is a diagram showing the relationship between the amount of change due to thermal expansion of the blade and the length of the blade, and Figure 2 is a diagram showing the blade length according to the present invention. A sectional view of the cleaning device, and FIG. 3 is a perspective view showing the main parts thereof. (1)...Photosensitive drum, (10)...Cleaning blade, (11)...Holder, (10a)
, (10a)...Slit, (δ)...Slit gap. Applicant Minolta Camera Co., Ltd. Figure l (a) WJI rlA<b>

Claims (1)

[Claims] 10. A blade cleaning device equipped with a blade member for removing residual toner adhering to the surface of a toner image carrier, characterized in that a slit is formed at the tip of the blade member in a direction perpendicular to the axial direction of the toner image carrier. cleaning equipment.