JP2853103B2 - Image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image forming apparatus such as a copying machine.

2. Description of the Related Art Conventionally, there is a copier as an image forming apparatus configured as shown in FIG. In FIG. 2, a document table M is disposed on the top of the copying machine main body 1. A light source L for irradiating the document surface, and a lens array for reflecting the reflected light on the surface of a photosensitive drum as a latent image carrier. LA etc. are arranged in the main body. In the main body, a photosensitive drum 2 formed in a rotating cylindrical shape and receiving an optical image formed by a lens array to form an electrostatic latent image, and a charger 3 for charging a photoconductive layer on the photosensitive drum surface near the periphery thereof are provided. It is arranged. In addition, the developing device 4 for supplying toner to the latent image to form a toner image, the transfer charger 6 for transferring the toner image to a transfer material supplied from a transport path, and no contribution to transfer. A cleaning device (hereinafter, referred to as a cleaner) 7 for removing toner from the surface of the photosensitive drum is provided.

Further, among these peripheral members, the photosensitive drum 2, the charger 3, the developing device 4, and the cleaner 7 are integrally mounted on the casing 11 to form a cartridge. It can be inserted and removed in the direction perpendicular to the paper.

The cleaner 7 is provided with a cleaning blade 7a, a magnet roller 7b, and a conveying screw 7c. The residual toner on the surface of the photosensitive drum reaches the position of the cleaning device with the rotation of the photosensitive drum, and is scraped off by the cleaning blade 7a. Is collected and conveyed by the rotating magnet roller 7b to reach the toner reservoir in the cleaner,
The toner is discharged out of the cleaner by the conveying screw 7c in this portion.

Conveyor screw 7c for the cleaner provided on the cleaner
Is assumed to temporarily extend outward in the direction perpendicular to the plane of the paper, and then bend in the direction of the cartridge and reach the bearing of the photosensitive drum 2.

The bearing portion (not shown) of the photosensitive drum 2 has a hollow shaft shape and receives the outer end of the transport screw, and transports between the cleaner side exit and the screw entry portion on the photosensitive drum side. The screw is surrounded by a flexible pipe.

With such a configuration, the toner scraped off by the cleaning blade is further fed and accumulated in the space inside the photosensitive drum via the pipe by the transport screw.

On the other hand, the developing device 4 is configured as shown in FIGS. FIG. 3 is a sectional view of the developing device 4 and FIG.
The figure is a plan view of the developing device. The developer is supplied from a hopper (not shown) on the front side of the developing device 4 in FIG. 2 and drops from a portion 4e in FIG. Then, the toner is sent from the conveying member (screw) 4c into the developing device, and is sent from the supply window 4d to the stirring member 4b side. After being agitated by the agitating member 4b, the photosensitive drum 2 is supplied to the developing sleeve 4a as a developer carrier.
Developed on

The transport member 4c starts rotating when it detects that the amount of the developer in the developing device 4 is small, supplies the developer into the developing device, and stops at other times. There is a type in which the member 4c is constantly rotating. In any case, the driving source is the photosensitive drum 2 or the developing sleeve.
4a and the stirring member 4b in many cases. This is because if the drive source of the transport member is separate from the drive source of the photosensitive drum, the size of the apparatus itself increases and the cost greatly increases.

In the above-described conventional example, when the copying machine is used for the first time at the user's site, there is a problem that the developer is scattered during transportation, so that the developing device is not filled with the developer. Installation work is required. In this installation work, a developing device installation mode is provided, and after supplying the developer to the hopper, in this installation mode, the transport member 4c rotates to supply the developer, and the developer amount detecting means provided in the developing device is provided. The rotation of the conveying member 4c is continued until it is detected that the developer is present.

[Problems to be Solved by the Invention] However, according to the above-described conventional example, the photosensitive drum 2 also keeps rotating while the transport member 4c is rotating. As a result, the cleaning blade 7a of the cleaner 7
When the rotation is continued in a state where the developer is not attached to the photosensitive drum surface, the frictional resistance with the photosensitive drum surface causes the fifth
It may be reversed as shown in the figure. When the cleaning blade 7a is inverted, as shown in FIG. 5, the cleaning blade 7a comes into contact with the surface of the photosensitive drum, causing not only poor cleaning but also an increase in the rotational torque for rotating the photosensitive drum 2. This also causes blur on the image. For this reason, when installing the developing device, it is not a simple task to reinforce the developer in the hopper, but rather a cumbersome operation such as disassembling a part of the developing device and replenishing the developer. ,
In addition, there is a problem that a complicated operation such as removing the cleaner once at the time of installation and attaching the cleaner again after the installation of the developing device is completed is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which solves the above-mentioned problems and in which the cleaning blade does not turn over during the first replenishment of the developer.

[Means for Solving the Problems] According to the present invention, the object is to provide a latent image carrier having a surface that is endless and movable, and a surface disposed opposite to the latent image carrier, and A charger for charging, a developing device disposed opposite to the surface downstream of the charger in the direction of movement of the surface, and abutting against the surface downstream of the surface of the developing device in the direction of movement of the surface. An image forming apparatus provided with a cleaning device that cleans the surface of the image forming apparatus, wherein at the time of the first replenishment of the developer to the developing device, the surface of the moving latent image carrier is charged by the charger for a predetermined period. The control means is set so that the charging is performed intermittently during the first replenishment of the developer.

[Operation] According to the present invention, when the replenishment of the developer is started at the time of the first replenishment of the developer, the surface of the latent image carrier also starts to move. At this time, the charger is energized, and the surface is uniformly charged. Then, the replenished developer adheres to the surface by electrostatic absorption. Therefore,
The frictional resistance between the member of the cleaning device and the surface is reduced, and the member is prevented from being inverted.

Embodiment An embodiment of the present invention will be described with reference to FIG. 1 of the accompanying drawings. 2 to 4 are denoted by the same reference numerals and the description thereof will be omitted.

The present embodiment is different from the above-described conventional example in that the surface of the photosensitive drum serving as the latent image carrier is charged and the developer is attached to the surface when the developer is initially supplied. Here, "at the time of the first replenishment of the developer" means a case where the developer is supplied into the developing device for the first time after the completion of the device.

Next, a control method of the present embodiment will be described with reference to FIG.

When installing the developing device, first, the developer is put into the hopper and set in the developing device. Next, when the developing device installation mode is turned on by a switch on the operation panel or the like (step 100 in FIG. 1), the developer conveying means 4c
Starts rotating (step 101). At this time, the photosensitive drum 2 also starts rotating. Then, when the charger 3 is energized (Step 102), the electric charge is loaded on the photosensitive drum 2, and the developer that has started to be supplied by the conveying means 4c adheres to the photosensitive drum 2 by an electrostatic absorbing force. As a result, the cleaning blade 7a enters between the cleaning blade 7a and the photosensitive drum 2 and reduces the frictional resistance between them, thereby preventing the cleaning blade 7a from being inverted. Further, when the developer is supplied, the supply of the predetermined amount is detected by the developer detecting means provided in the developing device (step 103), the rotation of the transport means is stopped, and the power supply to the charger 3 is stopped. (Step 104), the installation mode ends (Step 105). At this time, in order to prevent the cleaning blade from reversing, although it depends on the material of the cleaning blade and the surface of the photosensitive drum, a small amount of developer for lowering the frictional resistance may be supplied intermittently. , The power supply to the charger 3 is intermittently performed. Further, the light source L for irradiating the original may be appropriately turned on so that a small amount of charge does not get on the photosensitive drum. This also prevents useless use of the developer during installation. Immediately after the start of the installation mode, the developer is not supplied on the photosensitive drum because the developer is not sufficiently supplied.However, the cleaning blade does not turn over due to a short time, and a small amount of the developer is added to the cleaning blade in advance. Is applied, it is possible to more reliably prevent the blade from turning over.

In the present embodiment, the installation mode is released by the developer detection means.However, since the conveyance capacity of the conveyance means is predetermined, a timer is used, and the installation mode is released when a predetermined time has elapsed since the installation mode was turned on. You may do it.

[Effects of the Invention] As described above, according to the present invention, at the time of the first replenishment of the developer, the surface of the photosensitive drum is controlled so as to be intermittently charged, so that the developer adheres to the surface. As a result, reversal of the cleaning blade can be prevented, and the first developer replenishment operation is facilitated. Further, it is possible to prevent poor cleaning and adverse effects on images.

[Brief description of the drawings]

FIG. 1 is a flow chart showing a control process of one embodiment of the present invention, FIG. 2 is a cross-sectional view showing a schematic configuration of a conventional apparatus, and FIG. 3 is a cross-sectional view showing a schematic configuration of a developing device of the apparatus of FIG. FIG. 4 is a plan view of the apparatus of FIG. 3, and FIG. 5 is a view showing a state in which the cleaning blade is inverted in the apparatus of FIG. 2 latent image carrier (photosensitive drum) 3 charger 4 developing device 7 cleaning device (cleaner)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 21/00 370-540 G03G 21/10 G03G 13/08 G03G 15/08-15/08 507 G03G 13/02 G03G 15 / 02-15/02 103

Claims (1)

(57) [Claims] 1. A latent image carrier having an endless and movable surface, a charger disposed opposite to the latent image carrier to charge the surface, and a charger having a higher surface than the charger. A developing device disposed downstream of the developing device in opposition to the surface, and a cleaning device disposed in contact with the surface downstream of the developing device in a moving direction of the surface and cleaning the surface. The image forming apparatus further includes a control unit configured to charge the surface of the moving latent image carrier by the charger for a predetermined period when the developer is first supplied to the developing device; The image forming apparatus is characterized in that the means is set so that charging at the time of the first replenishment of the developer is performed intermittently.