JPS6080891A - Cleaning device - Google Patents

Abstract

PURPOSE:To enable detection of filling in a toner tank and clogging in a conveying passage with good accuracy by opening the discharge port of the passage for conveying a toner at the detecting level of the toner tank and detecting the reaction which the conveying screw provided to the conveying passage receives. CONSTITUTION:Respective stages for electrostatic charge, exposure, development and transfer are accomplished and the toner remaining on the surface of a photosensitive drum after transfer is scraped by a blade and is captured in a casing 10. The toner captured by the rotation of a helical spiring 17 in the casing 10 is conveyed in an arrow C direction and is discharged through the opening of a discharge cylinder 13 into a toner tank 22. While the discharge is normal, an actuator 18 is in a solid line position but when a detection level H is attained on increasing of the amt. of the toner 23 discharged into the tank 22, the discharge resistance in the cylinder 13 increases and therefore the actuator 18 is displaced by a distance delta in the right direction. The filling in the tank 22 is detected by detecting such displacement.

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 secondary recording medium, is uniformly charged and then exposed to light to form an electrostatic latent image. To static electricity! ! The image is 1-toner developed and the toner image is then transferred to a secondary recording medium, copy paper. Toner remaining on the surface of the photosensitive drum after the toner image is transferred is removed by a cleaning device for reuse.

This cleaning device uses a fur brush that scrapes the surface of the photosensitive drum with a soft rotating brush to remove residual toner, and a fur brush that removes residual toner by rubbing a blade made of elastic material against the surface of the photosensitive drum. There's something to scrape off. Toner removed from the photosensitive drum is, for example, removed by a vacuum cleaner in a fur brush cleaning device, and accumulated in a toner tank in a blade cleaning device. A 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 contamination.

In order to prevent the toner from overflowing from the toner tank, it is possible to increase the capacity of the toner tank to prevent overflow, but there is a limit due to the shape. It is also possible to measure the weight of the toner tank and replace or clean the toner tank before filling it, but since toner is lightweight, the measurement error would be large and this would be impractical.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact and practical cleaning device that can accurately detect malfunctions of the device in advance by monitoring the toner transport state or the filling of the toner tank.

[Summary of the invention]

In order to achieve this object, the present invention opens the discharge port of the toner transport passage to the detection level of the toner tank, and also includes a detection mechanism that responds to the magnitude of the reaction force received by the toner transport screw provided in the transport passage. The present invention is characterized in that it detects an increase in the reaction force applied to the conveyance screw due to the filling of the toner tank or the clogging of the conveyance passage, thereby detecting in advance that a malfunction of the cleaning device occurs. .

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the cleaning device of the present invention applied to an electrophotographic copying machine will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a partially sectional plan view, FIG. 2 is a cross-sectional view taken along the line ■-■, and FIG. 3 is a cross-sectional view taken along the line tom.

A blade 2 is attached to 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 the 1-toner remaining on the surface of the drum after the transfer is completed. be touched. Auxiliary metal fitting 3 holding blade 2 with adhesive
It is fixed to the holder 5 by the spring 4, and the holder 5
is rotatably held between cleaner side plates 7a and Vb by support pins 6. 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 1-hener 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 stacked in a toner conveying passage casing 10 having a C-shaped cross section. In order to make the space partitioned by the photosensitive drum 1, the blade 2, the sides Fi 7a and 7b, the toner guide 9, and the casing 10 into a substantially closed space, a seal is provided between the lower surface of the blade 2 and the upper outer surface of the casing 10. A member 11 is arranged. The cleaner side plates 7a and 7b are fixed between the main body side plates 12a and 12b,
A discharge pipe 13 provided on the outside of the side plate 7a and communicating with the casing 10 extends to the outside of the main body side plate 12a 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 IO. 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 the helical spring 17 is attached as a creu. The helical spring 17 is housed in the inner cavity of the casing 10, and the other end has a protrusion 13
The free end is exposed to the outside, and the actuator 18 is attached to the outer end. 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 into which the #1 barrel 13 is fitted is disposed on the outside of the main body side plate 12a. The opening 22a of the toner tank 22 is installed at a level detection position for the discharged toner 23 contained therein, and when the opening 22a is fitted into the discharge cylinder 13, the outer end of the helical spring 17 and the operating The child 18 is housed in the tank. As will be described later, the actuator 18 is connected to a helical spring 1FII from the outside of the toner tank 22.
The positional change in the direction of the I-center is detected, and it is placed close to the wall of the I-ner tank to facilitate detection from the outside. Further, in this embodiment, when the toner 23 discharged into the toner tank 22 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. Therefore, it is preferable to narrow the internal space of the 1-toner tank 22 in the detection level section so as to prevent 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 so that its position relative to the actuator 18 can be adjusted using a mounting screw 24b. When using a proximity switch that responds to metal or magnetic material as the detection element 24c,
AI that this proximity switch strongly senses the actuator 18;
Made from Fe etc.

In the above configuration, when the electrophotographic copying machine is operated,
The photosensitive drum 1 is rotated in the direction of the arrow by a drive motor 21, and electrophotographic processes such as charging, exposure, development, and transfer are performed. 1 remaining on the surface of the photosensitive drum 1 after transfer
- The ner is scraped off by the blade 2 and the casing 1
Captured within 0. Helical spring 1 inside casing 10
7 is rotated in the direction of arrow B, the toner captured in this casing lO is conveyed in the direction of arrow C along the casing vagina, and is discharged into the toner tank 22 from the opening of the discharge tube 13.

When the toner is normally discharged from the discharge pipe 13 into the toner tank 22, the reaction force in the axial direction that the helical spring 17 receives is small, so the helical spring 17 is in an extended state and the actuator 18 is It is located at the position shown by the solid line. However, the 1-toner 2 discharged into the toner tank 22
When the value of 3 increases and reaches the C detection level H, the output of 1 to f-ai is not smooth (as a result, it becomes clogged in the discharge tube 13, and the discharge resistance becomes large.
The reaction force acting on I also increases, and this helical spring 17
is compressed in the axial direction, and the actuator 18 attached to its outer end is displaced six dimensions to the right as shown by the chain line.

Therefore, in response to the displacement of the actuator 18, the detector 2
By positioning the four detection elements 24c, it is possible to detect whether the l-ner tank 22 is full. This detection is more precise than that by heavy weight measurement, and is
There is no need to make 2 larger.

Even if the toner tank 22 is not filled, if a toner jam occurs in the inner cavity of the casing 10 or the discharge pipe 130 due to some reason, the reaction force acting on the helical mackerel 1517 will be reduced, causing the same problem as described above. Displacement of the actuator 18 occurs. Therefore, such a state can also be detected by the detection element 24c.

In order to notify the operator of such a state, the tFi notification lamp may be turned on and off by the detection element 24c.

The embodiment described above uses a helical spring 17 for conveying toner.
When the conveyance path is clogged, the helical spring 17 is compressed and deformed by the reaction force caused by the filling of the toner tank 22 to displace the operating check 8. However, the helical spring 17 is Formed by a rigid body, FAa axis]
, 4 (=The same effect can be obtained by elastically deforming the J section or by making the drive phase 14 move elastically.

〔Effect of the invention〕

As described above, according to the present invention, the discharge port of the 1 henna transport passage is opened at the detection 1 novel of the toner tank, and is installed in this transport passage =t7=-!・A detection mechanism is installed that depends on the magnitude of the reaction force received by the toner image transport knee, and detects whether the toner tank is full or the PI transport path is full. A small and practical cleaning device that can detect with high precision is used.

[Brief explanation of the drawing]

The drawing shows one embodiment of the present invention, and E4'r 1
[-II is a partially cross-sectional plan view, Figure 2 is the n of Figure 1
3 is a sectional view of FIG. 1 at m-Ill. ]...Photosensitive drum 15.2...Blade, l ('l...Casing for toner conveyance passage, 1
,;・・Ejection tube. F... Toner transport roll mackerel: J, a,...
i,'! ... Actuator, 22 ... Toner tank 2 /i ... Detector, 2.1c ...
・Detection element. lI2 diagram

Claims (1)

[Claims] (1) After the toner image has been transferred to the secondary recording medium, the toner remaining on the surface of the primary recording medium is removed, and the removed toner is transferred to the toner by rotating a conveyance screw provided in the conveyance path. A cleaning device configured to discharge water into a tank, characterized in that the discharge port of the conveyance path is opened to a detection level of the toner tank, and a detection mechanism is provided that responds to the magnitude of reaction force received by the conveyance screw. cleaning equipment. 2. In claim 1, the screw uses a helical spring whose free end is on the discharge port side, and the detection mechanism includes a detected object provided at the free end of the helical spring and the toner tank. and a proximity switch facing the detected object from the outside.