JPH0150909B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cleaning device for removing toner remaining on the surface of a primary recording medium used repeatedly in an electrophotographic copying machine or the like.

[Background of the invention]

In an electrophotographic copying machine, the surface of a photosensitive drum, which is a primary recording medium, is uniformly charged and then exposed to light to form an electrostatic latent image. The electrostatic latent image is developed with toner, and the toner image is then transferred to copy paper, which is a secondary recording medium. Toner remaining on the surface of the photosensitive drum after the toner image is transferred is removed by a cleaning device for reuse.

These cleaning devices include those that use a fur brush that removes residual toner by scrubbing the surface of the photosensitive drum with a soft rotating brush, and those that use a blade made of an elastic material to scrape off residual toner by touching the surface of the photosensitive drum. There is something. Toner removed from the photosensitive drum is removed, for example, by a vacuum cleaner in the case of a fur brush cleaning device, and accumulated in a toner tank in the case of a blade cleaning device. A rigid conveyance screw is provided in the toner conveyance path for conveying the toner scraped off by the blade to the toner tank. However, since toner is fine particles and has poor fluidity, it can stick to the conveyance path and cause conveyance failures, or the toner tank may become full and toner overflows from the tank or the conveyance path into the machine, damaging equipment or copying paper. There was a problem of staining the .

Therefore, the conveyance screw is constructed so that it can move in the direction of its rotation axis in response to the magnitude of the toner reaction force that the conveyance screw receives. When the reaction force increases and the conveying screw moves a predetermined distance in the direction of the rotation axis, a detector such as a micro switch installed opposite the end of the conveying screw operates to detect whether the toner tank is full or not. This is proposed in Japanese Utility Model Application Publication No. 154749/1983.

However, in this method, the conveyance screw is made of a rigid body, and the entire conveyance screw made of this rigid body can be moved in the direction of its rotation axis. It is necessary to configure the conveyor screw so that it can freely move in both directions, and to prevent toner from leaking to the outside when the conveying screw moves in both directions. Therefore, the shaft of the conveying screw moves in the direction of the rotation axis due to the reaction force of the toner, but the seal has strong contact pressure against the shaft against movement in both directions, and the conveying screw Since the shaft is located in the conveyance screw passage and has toner attached to it, it is difficult to move, and although it is necessary to detect the fact that the conveyance screw moves in the direction of the rotation axis when the toner tank is full, etc. First, there is a problem that the reliability of the operation is poor, such as the fact that the conveying screw does not move in the direction of the rotation axis and cannot be detected. Further, it is necessary to add a spring or the like to hold the conveying screw at a steady position in the direction of the rotation axis, which causes the problem that the structure becomes complicated.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable cleaning device that has a simple structure and can monitor the filling of a toner tank and the state of toner transport to detect a malfunction in the device in advance.

[Summary of the invention]

In order to achieve this object, the present invention comprises a conveying screw with a helical spring whose one end on the side opposite to the discharge port is fixed in the direction of the rotation axis and the other end on the side of the discharge port is free in the direction of the rotation axis. , an actuator is provided at the free end of the actuator, and a means for detecting displacement of the actuator in the rotational axis direction is provided opposite to the actuator.
When the reaction force of the toner increases due to filling of the toner tank, etc., the helical spring is compressed and the actuator provided at its free end is displaced, so this displacement is detected.

[Embodiment of the Invention] Hereinafter, an embodiment of the cleaning device of the present invention applied to an electrophotographic copying machine will be described with reference to FIGS. 1 to 3. Figure 1 is a partially cross-sectional plan view;
FIG. 2 is a sectional view thereof, and FIG. 3 is a sectional view thereof.

A blade 2 is brought into contact with the surface of the photosensitive drum 1, on which the electrophotographic copying process of uniform charging, exposure, development, and transfer is performed, for scraping off toner remaining on the surface of the drum after the transfer is completed. Ru. blade 2
The auxiliary fitting 3 which is adhesively held is fixed to the holder 5 by screws 4, and the holder 5 is rotatably held by support pins 6 between cleaner side plates 7a and 7b. The tension spring 8 applies a rotational force to the holder 5 so as to press the blade 2 against the surface of the photosensitive drum 1. The toner scraped off by the blade 2 and falling along the surface of the photosensitive drum 1 is received by a flexible toner guide 9 and accumulated in a toner transport passage casing 10 having a C-shaped cross section. Photosensitive drum 1, blade 2, and side plates 7a, 7
In order to make the space partitioned by b, toner guide 9, and casing 10 into a substantially closed space,
A sealing member 11 is arranged between the lower surface of the blade 2 and the outer peripheral upper surface of the casing 10. The cleaner side plates 7a and 7b are fixed between the main body side plates 12a and 12b, and the discharge tube 13 provided outside the side plate 7a and communicating with the casing 10 is connected to the main body side plate 12a.
It is extended to the outside and is open.

A drive shaft 14 is attached to the cleaner side plate 7b so as to be concentric with the inner cavity of the casing 10. This drive shaft 14 is prevented from moving in the axial direction by a retainer 15, a gear 16 is fixed to the outer end, and one end of a helical spring 17 as a toner conveying screw is attached to the inner end. The helical spring 17 is housed in the inner cavity of the casing 10, and the other end is exposed outside from the discharge tube 13 to become a free end, and the outer end has an actuator 18.
can be installed. The gear 16 is driven by a drive motor 21 via a gear 20 together with a photosensitive drum drive gear 19 .

A plastic toner tank 22 having an opening 22a fitted into the discharge pipe 13 is disposed on the outside of the main body side plate 12a. The opening 22a of the toner tank 22 is provided at a level detection position of the discharged toner 23 contained therein.
In the state in which the coil a is fitted into the discharge tube 13, the outer end of the helical spring 17 and the actuator 18 are housed in the tank. As will be described later, the actuator 18 is used to detect positional fluctuations in the axial direction of the helical spring from the outside of the toner tank 22, and is positioned close to the toner tank wall to facilitate detection from the outside. be made into Further, in this embodiment, the toner tank 22
When the discharged toner 23 reaches the detection level, a large reaction force is applied to the helical spring 17, and the displacement of the actuator 18 due to the contraction of the helical spring 17 is detected. It is preferable to narrow the internal space of the toner tank 22 so as to hinder the free movement of the toner 23 as much as possible.

The detector 24 includes a holding arm 24a fixed to the main body side plate 12a, and a detection element 24c attached to the holding arm 24a with a mounting screw 24b so that its relative position to the actuator 18 can be adjusted. When using a proximity switch that responds to metal or magnetic material as the detection element 24c, the actuator 1
8 is made of Al, Fe, etc., which this proximity switch strongly feels.

In the above configuration, when the electrophotographic copying machine is operated, the photosensitive drum 1 is rotated in the direction of arrow A by the drive motor 21, and is charged, exposed, developed, and
An electrophotographic process of transfer is performed. Toner remaining on the surface of the photosensitive drum 1 after the transfer is scraped off by the blade 2 and captured in the casing 10. Since the helical spring 17 inside the casing 10 is rotated in the direction of the arrow B, the toner captured in the casing 10 is transported along the casing inner cavity in the direction of the arrow C, and is discharged from the opening of the discharge pipe 13 into the toner tank. 22.

When the toner is normally discharged from the discharge tube 13 into the toner tank 22, the helical spring 17
Since the reaction force in the axial direction received by the actuator 18 is small, the helical spring 17 is in an extended state and the actuator 18 is in the position shown by the solid line. However, when the amount of toner 23 discharged into the toner tank 22 increases and reaches the detection level H, the toner is no longer discharged smoothly and becomes clogged in the discharge tube 13, increasing the discharge resistance. For this purpose, I will make a vine roll 1
The reaction force acting on the helical spring 17 also increases, and the helical spring 17 is compressed in the axial direction, and the actuator 18 attached to its outer end is displaced eight dimensions to the right as shown by the chain line.

Therefore, by positioning the detection element 24c of the detector 24 so as to respond to the displacement of the actuator 18, it is possible to detect whether the toner tank 22 is full.

Even if the toner tank 22 is not filled, if toner is clogged in the inner cavity of the casing 10 or the discharge pipe 13 for some reason, the reaction force acting on the helical spring 17 increases, causing the same displacement of the actuator 18 as described above. Occur. Therefore, such a state can also be detected by the detection element 24c.

In order to notify the operator of such a state, the notification lamp may be made to blink using the detection element 24c.

〔Effect of the invention〕

As explained above, according to the present invention, the conveying screw is constituted by a helical spring whose one end on the side opposite to the discharge port is fixed in the direction of the rotation axis and the other end on the side of the discharge port is free in the direction of the rotation axis. At the same time, an actuator is provided at the free end of the actuator, and a means for detecting the displacement of the actuator in the direction of the rotational axis is provided opposite to the actuator. Since the coil spring is compressed and the displacement of the actuator is detected by the detection means, there is no need to move the entire conveying screw in the direction of the rotation axis unlike in the case of rigid conveying screws. It is sufficient to detect the displacement of the actuator due to the compression of the helical spring. Therefore, the reaction force of the toner exerted on the conveying screw can be reliably detected and the reliability of the operation can be improved. Further, since the conveying screw itself is made of a spring, there is no need to add a new spring or the like to hold it in a steady position unlike the conveying screw made of a rigid body, and the structure can be simplified accordingly. Furthermore, the conveyance screw itself is composed of a helical spring, and the long and large-diameter helical spring provides an elastic force that counters the reaction force of the toner. The relationship between the amount of displacement can be arbitrarily set over a wide range, thus enabling highly accurate detection.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a partially sectional plan view, and FIG. 2 is a cross-sectional view of FIG. 1.
The sectional view, FIG. 3, is a - sectional view of FIG. 1. 1...Photosensitive drum, 2...Blade, 10...
Toner conveyance passage casing, 13...discharge tube,
17... Helical spring for toner conveyance, 18... Operator, 22... Toner tank, 24... Detector,
24c...Detection element.

Claims (1)

[Claims] 1. A means for removing the toner remaining on the surface of the primary recording medium after the toner image is transferred to the secondary recording medium, a casing for the toner conveyance path that guides and receives the removed toner, and a casing for the toner conveyance path. a toner tank that accumulates toner discharged from the discharge port of the casing; and a toner tank that is provided within the toner transport passage casing and rotates in a predetermined direction to transport the toner within the toner transport passage casing and discharge it to the toner tank. In a cleaning device equipped with a conveyance screw and a detection mechanism that responds to the magnitude of toner reaction force that the conveyance screw receives, one end of the conveyance screw on the side opposite to the discharge port is fixed in the rotation axis direction, It consists of a helical spring whose other end is a free end in the direction of the rotation axis, an actuator is provided at the free end, and means for detecting displacement of the actuator in the direction of the rotation axis is provided opposite to the actuator. A cleaning device characterized in that: