JPS58149083A - Cleaning device of rotary brush type - Google Patents

Abstract

PURPOSE:To maintain always adequate cleaning capacity, by monitoring the replenishing rate of toners in a developing device and controlling the rotating speed automatically. CONSTITUTION:The inflow rate of toners into a developing device 2 is detected with the rotating speed of a control roll 21 for sprinkling or an optical sensor, and is inputted to a control device 22. The device 22 controls the number of revolutions of a motor 19 of a cleaning device 10 so as to increase the number of revolutions of the motor 19 when the rate of relenishing of the toners is larger and to decrease the number of revolutions thereof when the rate of replenishing is smaller according to the replenishing rates of the toners.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for a copying machine, and more particularly to a rotating brush type cleaning device that removes developer remaining on a photoreceptor by rotating a plan.

The cleaning ability of the rotating brush type cleaning device used in copying machines is influenced by the force with which the brush presses the photoreceptor (nip) and the number of rotations of the brush.If this cleaning ability is low, poor cleaning may occur and residual developer may be removed. As a result, the image quality of subsequent copies is degraded due to the formation of scratches.

In conventional copying machines, the cleaning brush rotates at a fixed speed at a fixed position and its cleaning ability remains constant, but the toner density in the developing device may change, making it difficult to clean the brush sufficiently when the toner density is high. There was nothing to do for a while. In order to solve this problem, it is possible to increase the cleaning force by increasing the rotational speed and pressing the brush strongly against the photoconductor, but if high cleaning performance is maintained for a long period of time, the brush will strongly press the photoconductor. The flowers are rubbed and heat is generated there, and the toner is
This can cause a thin film to adhere to the photoconductor or create streak-like scratches along the brush on the photoconductor. The above-mentioned thin film is undesirable because it deteriorates the radiation characteristics of the photoreceptor and maintains a high potential in the background area, which should be at a low potential, thereby degrading the image quality of the copy.

Therefore, an object of the present invention is to provide a rotating brush type cleaning device t that always maintains an appropriate cleaning ability.

According to the present invention, in order to achieve the above object, in a rotating brush type cleaning device that removes developer remaining on the surface of a photoreceptor after the image developed by the developing device is transferred, the amount of toner supplied to the developing device is monitored. , a cleaning device is provided which is characterized by controlling the rotational speed of its own brush to be lowered when the amount of replenishment is small, and to increase the rotational speed of the brush when the amount of replenishment is large. The cleaning capacity can be varied to sufficiently clean residual toner even when the toner concentration is high, while the brush rotational speed is not kept high to prevent the formation of a thin film or streak-like scratches. I'm here.

The present invention will be described in detail below using the drawings.

The latent scratches formed on the photoreceptor 1 are developed by the developing device 2, and the developed toner is transferred onto the paper 3. By this transfer, most of the toner is transferred to the paper, but since the latent scratches on the photoreceptor 1 have not disappeared, seven parts of the toner remain.

This residual toner is removed by the rotary bluff type cleaning device 1 according to the present invention.
Cleaned out by 0.

The cleaning device 11G is surrounded by a housing 11, and two rotating brushes 12, 13 are installed on the photoreceptor 1.
They are arranged so that they touch each other. This rotating brush is preferably a so-called fur brush, which is made of a large number of soft but strong thin fibers. Rotating brushes 12 and 13
are connected by transmission gears 14,15 so that their rotations are reversed. The brush 12 also has a gear 16, receives power from a motor 19 through a chain 18 suspended through a tension gear 17, and rotates in the direction of the arrow. That is, the brush 12 rotates in the same direction as the photoreceptor 1, and the brush 13 rotates in the opposite direction. By doing this, most of the residual toner that is weakly adhering to the photoreceptor is removed, and a small amount of toner that is strongly adhering is removed by the brush 13. Although it is preferable to use a reversible coplash as in this embodiment, it is of course possible to use a single brush with a limited number of brushes to achieve sufficient removal.

In the present invention, the speed of the motor 19 is controlled by the swinging hammer control roll 21 (
This is controlled according to the toner replenishment amount (controlled by motor M). That is, the flow rate of toner into the developing device 2 is detected by the rotational speed of the swing control roll or the optical sensor, and is inputted to the control device 22. The control device 22 controls the rotation speed of the motor 19 of the cleaning device 10 in accordance with the amount of toner replenishment so that when the amount of replenishment is large, the rotation speed of the motor 19 of the cleaning device 10 is increased, and when the amount of replenishment is small, the rotation speed of the motor 19 is decreased.

As the toner concentration in the developing device increases, the amount of residual developing agent also increases, but according to the present invention, in this case, the rotating speed of the brush increases and the cleaning ability is enhanced, so that sufficient cleaning can be achieved. On the other hand, this cleaning ability decreases accordingly when the toner concentration reaches a normal level, so that the toner does not form a thin film or create streaks on the photoreceptor.

[Brief explanation of drawings]

The drawing is a schematic 8-sided view of a copying machine using the rotating brush type cleaning device of the present invention. 1... Drum-shaped photoreceptor, 2... Developing device (10.
・・Cleaning device, 12, 13 ・・Rotating brush, 14.1
5,111... Gear, 1T... Tension gear, 1B... Chain 19... Motor, 20... Toner supply device, 21...
... Toner distribution control roller, 22 ... Control device.

Claims (1)

[Claims] In the rotating brush/cleaning device that removes the developer remaining on the photoreceptor surface after the image has been transferred by the dusting device,
This cleaning device monitors the amount of toner replenishment in the current device, and controls the rotational speed of the brush to decrease when the amount of replenishment is low, and to increase the rotational speed of the brush when there is a large amount of replenishment.