JPS61124979A - Blade cleaning device - Google Patents

Abstract

PURPOSE:To prevent a cleaning blade, a photosensitive drum, and a driving system from damaging by detecting the movement of the blade from the surface of a photosensitive body against the energizing force of an energizing means, and stopping driving the photosensitive body and reversing it by a specific angle successively. CONSTITUTION:When frictional force increases abnormally between the photosensitive drum P and cleaning blade 1, the contact of the blade 1 for the photosensitive drum P moves to a position T1 at the rotation-directional downstream and the blade 1 itself deforms, so that a holder 2 moves away from the photosensitive drum P as a reaction. Then, a support means 5 which supports the holder 2 with a screw 4 is guided to a bearing 7 against the press-contacting force of a spring 9 to move in the same direction, thereby turning on a microswitch SW with a pressure part 8. Then, a CPU100 outputs a driving stop signal to a driver circuit 101 to stop a driving motor M and also stop the rotation of the photosensitive drum P. Further, a reverse driving signal is outputted for a certain time and the driving motor M is driven reversely to reverse the photosensitive drum P by the certain angle.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a blade cleaning device for removing toner remaining on the surface of a photoreceptor of an electronic copying machine.

2. Description of the Related Art As a means for removing toner remaining on the surface of a photoreceptor in an electronic copying machine, a blade cleaning device that presses a cleaning blade made of a flexible member onto the surface of the photoreceptor and scrapes off the toner remaining on the surface of the photoreceptor. is widely known.

For example, in Japanese Patent Application Laid-Open No. 47-45933, as shown in FIG. The pressure angle (θ) with respect to the advancing direction is 0°〈
A blade cleaning device is disclosed in which a blade (1a) is pressed against a photoreceptor drum (3a) by a spring (4a) with an appropriate pressure so that θ<90°.

In the blade cleaning device of the above type, it is important to set the pressing force of the blade (1a) to the surface of the photoreceptor drum (3a).

When the pressure contact force of the blade (1a) is strong, although it shows good leaning performance in normal operation, the blade (1a) and the photoreceptor may be damaged due to toner sticking to the surface of the photoreceptor drum (3a). When the frictional force between the blade (1a) and the drum (3a) becomes abnormally large, the blade (1a) may turn over as shown in FIG. If the blade (1a) turns over, it will not only become unusable, but also damage the surface of the photoreceptor drum (3a), and even cause serious damage to the drive system of the photoreceptor drum (3a). This results in overeating, which can cause serious damage to the drive system.

On the other hand, the blade (1a
) If the pressing force is weak, there will be an inconvenience that the normal cleaning performance will be degraded.

The present invention provides a blade (1a) that has good leaning properties in normal operation, and even when the frictional force between the blade (1a) and the photoreceptor drum (3a) increases for some reason. It is an object of the present invention to provide a blade cleaning device that does not cause damage to a photosensitive drum (3a) and its drive system.

Means for Solving the Problems The present invention provides a blade cleaning device in which the tip of the cleaning blade makes an acute angle with the rotational direction of the photoreceptor and is pressed against the surface of the photoreceptor.
a supporting means that supports the cleaning blade so that its tip is movable in a direction in which the tip comes into pressure contact with the surface of the photoreceptor and a direction in which it retreats; and a support means that urges the cleaning blade through the support means so that its tip comes into pressure contact with the surface of the photoreceptor. The urging means and the cleaning blade resist the urging force of the urging means,
an abnormality detection means for detecting that the cleaning blade has moved in a direction of retraction from the surface of the photoreceptor; and when the abnormality detection means detects the retraction of the cleaning blade from the surface of the photoreceptor, the rotational drive of the photoreceptor is stopped; and control means for controlling the photoconductor to subsequently rotate the photoconductor in the opposite direction by a certain angle.

Effect In the above configuration, when the frictional force between the photoreceptor and the cleaning blade becomes abnormally large (for some reason),
The cleaning blade retreats against the urging force of the urging means. When the abnormality detection means detects this cleaning blade retreat, the rotational drive of the photoreceptor is stopped by the control means. Thereafter, the photoreceptor is rotated in the opposite direction by a certain angle to return the retracted cleaning blade to its original normal pressure contact state.

Embodiment FIG. 1 shows a schematic configuration of the main parts of a copying machine equipped with a blade cleaning device according to the present invention. In the figure, (1) is a cleaning blade made of a flexible material such as polyurethane rubber; The ends are glued to the holder (2) forming a blade assembly (3). The blade assembly (3) is attached to the support means (5) with screws (4).

The support means (5) supports the cleaning blade (1) at an angle (5) that the tip of the cleaning blade (1) makes with the photoreceptor drum (P) in its rotational direction. It is movable in the direction of pressure contact with the surface of the photoreceptor drum (P) and the direction of retreat.

A suppressing part (8) is formed at the end of the shaft part (6), and in this pressing part (8) the supporting means (5) is connected to a spring (
9). This biasing force brings the cleaning blade (1) into pressure contact with the photosensitive drum (P).

, A regulating member (10) is provided on the opposite side of the spring (9) with respect to the pressing portion (8). This regulating member (10) is supported by a support means (
5) When the cleaning blade (1) is biased in the direction of the photoconductor drum (P), the cleaning blade (1) comes into contact with the pressing portion (8) to regulate the biasing force of the spring (9), and the cleaning blade (1) It regulates the pressing force against the surface.

In the normal operating state, the suppressing portion (8) is brought into contact with the regulating member (10) by the biasing force of the spring (9).

Regarding the suppressing part (8), on the same side as the spring (9), the suppressing part (8) is retracted, that is, the photoreceptor drum (
A microswitch (SW) is also provided to detect movement in the direction away from P).

The retraction of the suppressor (8) as described above is caused by the friction between the cleaning blade (1) and the photoreceptor drum (P) becoming abnormally large due to toner sticking, etc., which causes the cleaning blade (1) to turn over. Occurs when climbing.

The details will be explained with reference to FIG. 2. During normal operation, as shown in FIG. 2a, the cleaning blade (1
) is a photosensitive drum (P) rotating in the direction of the arrow (CCW).
), the contact point (
(To).

However, a photosensitive drum? ) If the frictional force between the photosensitive drum (P) and the cleaning blade (1) becomes abnormally large due to toner sticking to the surface of the cleaning blade (1), as shown in Figure 2, The contact point with respect to the photoreceptor drum (P) or its position downstream in the rotational direction (
rx), the cleaning blade (1) itself deforms, and the reaction causes the holder (2) to deform the photoreceptor drum CP).
move away from.

When the frictional force further increases, as shown in FIG. 2C, the photosensitive drum (P) of the cleaning blade (1)
The contact point moves further downstream to position 11 ('r2), causing the cleaning blade (1) to move upwards, and further causing irreversible deformation of the cleaning blade itself or peeling off from the blade (2). This will cause the product to become unusable. At this time, the photoreceptor drum (P
) move further away from

, as mentioned above, due to the increase in the frictional force between the photoreceptor drum (P) and the cleaning blade (1), 'J -
Due to the deformation of the cutting blade (1), the hot redder (2)
When the photoreceptor (2) moves away from the photoreceptor drum (I), the support means (5) to which the photoreceptor (2) is fixed with the screw (4) resists the pressing force of the spring (9). bearing(
7) and moves in a direction away from the photoreceptor drum (P).

At this time, the microswitch (SW) is connected to the suppressor (8).
is turned on by

FIG. 3 shows a control circuit that associates the state of the cleaning blade (1) with the rotational drive of the photosensitive drum (P), and (100) is a microcomputer (7) CPU.

(200) is a drive motor HO') driver circuit for driving the photoreceptor drum, (102) is a ROM, (103
) are switches and sensors provided in the copying machine other than the above-mentioned microswitch (SW).

In the above configuration, when the power is turned on to the copier main body,
When the microswitch (SW) is open, that is, when the pressure contact state of the cleaning blade (1) is normal, the CPU (100) operates the switches/sensors (103).
A signal for driving the drive motor (b) is output to the driver circuit (101) according to the procedure described in the ROM (102) according to the state of the drive motor (b).

On the other hand, when the microswitch (SW) is closed, that is, when the cleaning blade (1) and the photoreceptor drum (P)
When the frictional force between CPU (1) increases abnormally and deforms the blade (1), CPU (1)
00) outputs a drive stop signal to the driver circuit (101), the rotation of the drive motor (B) is stopped, and the rotation of the photosensitive drum (P) is also stopped.

When the rotation of the photoreceptor drum (P) stops, the C
A reverse drive signal is outputted from the P U (100) to the driver circuit (101) for a certain period of time, the drive motor (B) is driven in the reverse direction, and the photosensitive drum (P) is rotated in the reverse direction by a certain angle.

The timing at which the microswitch (SW) is turned on is preferably set so that it is turned on when the cleaning blade (1) begins to undergo abnormal deformation, that is, in the state shown in Figure 2. .

By setting in this manner, the cleaning blade (1) can clean the photoreceptor drum before it undergoes significant deformation as shown in FIG. 2C. ) can be stopped, and damage to the photoreceptor drum (P) and cleaning blade (1) themselves can be prevented.

Further, the reversal angle of the photoreceptor drum (P) is determined by detecting whether the cleaning blade (1) is deformed or not.
From the state where P) is stopped, that is, the state shown in Figure 2,
The cleaning blade (1) is attached to the photoreceptor drum (P) l
The angle should be set so that it returns to the normally pressed state, that is, the state shown in FIG. 2a. With this setting, the abnormally deformed cleaning blade (1
) to quickly return it to normal condition. Therefore, mechanical fatigue exerted on the cleaning blade due to abnormal deformation can be minimized, and irreversible deformation of the cleaning blade due to accumulation of mechanical fatigue can be prevented.

Effects of the Invention As is clear from the above explanation, the blade cleaning device of the present invention immediately stops the rotation of the photoreceptor when the frictional force between the cleaning blade and the photoreceptor becomes abnormally large. Therefore, the cleaning blade does not turn over, and therefore, no damage occurs to the cleaning blade, photoreceptor, or drive system. Also,
After the rotation of the photoconductor stops, the photoconductor is subsequently rotated in the opposite direction at a certain angle, so that the cleaning blade, which is in pressure contact with the stopped photoconductor in a deformed state, quickly returns to its normal pressure contact state. This has excellent effects such as being able to prevent irreversible deformation of the cleaning blade due to the accumulation of mechanical fatigue.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic configuration of a blade cleaning device according to the present invention, FIG. 2 is a view showing how the cleaning blade is turned over, FIG. 3 is a circuit diagram showing a control circuit, and FIGS. Figure 5 shows slave 9...spring
100...CPU5W...-Microswitch Applicant: Minolta Camera Co., Ltd. Figure 1 SW outfitter

Claims (1)

[Claims] 1. In a blade cleaning device in which the tip of the cleaning blade makes an acute angle with the rotating direction of the photoreceptor and presses against the surface of the photoreceptor, the cleaning blade is moved in the direction in which the tip comes into pressure contact with the surface of the photoreceptor. and a support means for movably supporting the cleaning blade in the retracting direction; a biasing means for biasing the cleaning blade so that its tip comes into pressure contact with the surface of the photoreceptor through the support means; an abnormality detection means for detecting that the cleaning blade has moved in a direction away from the surface of the photoreceptor against the urging force of the urging means; and when the abnormality detection means detects that the cleaning blade has moved away from the surface of the photoreceptor. 1. A blade cleaning device comprising: control means for stopping the rotation of the photoreceptor and then controlling the photoreceptor to rotate in the opposite direction by a certain angle.