JPS63189882A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent a new developing device from being mixed with old develper by providing a control means for repalcing a developing device in a state that the developer has been recovered to the develping means by a recovering means. CONSTITUTION:When the life of a developer is ended, a cleaner 15 and a recovering device 33 are driven by a controller 41 the toner left in the cleaner 15 recovered to the developing device 12 and the then the end of life of the developer is displayed on a display device 45 on an operation panel 44. Since the developing device 12 is replaced after recoving the old toner left in the cleaner 15 to device 12, the toner left in the cleaner 15 is not mixed into a new developing device, a change in concentration of the developer can be prevented and the new developing device can be surely initialized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] <Industrial Application Field> The present invention relates to an image forming apparatus such as a laser printer.

(Prior Art) Recently, in image forming apparatuses, an electrostatic latent image formed on a photoreceptor drum is developed by a developing device, and after the developed image is transferred onto paper, it is transferred onto the photoreceptor drum. Image forming apparatuses have been developed in which residual toner is scraped off by a cleaner, and the scraped off toner is collected in a developing device and reused.

This type of image forming apparatus has one developing device per photosensitive drum unit! For example, when the developer contained in the developing device reaches the end of its lifespan, the entire developing device can be replaced with a new developer.

By the way, in this type of image forming apparatus, when the developer bag is replaced with a new one, the initial setting of the magnetic sensor that detects the developer concentration based on the new developer stored in the developer bag is changed. is now being carried out.

However, when a new developing device is attached to the photoreceptor drum unit, the toner remaining in the cleaner is collected by the collecting device into the developing device, which changes the toner concentration of the new developer and causes the initial detection of the magnetic sensor. An error occurs in the settings and the developer (problem to be solved by the invention) This invention solves the problem that when the developing device is replaced, the concentration of the new developer changes due to the mixing of old toner, and it is difficult to accurately determine the developer concentration. The objective is to prevent old toner from mixing with new developer and to accurately detect developer concentration. The present invention aims to provide an image forming apparatus.

[Structure of the Invention] (Means for Solving the Problems) The present invention develops a latent image formed on an image carrier by a developing means that is detachably attached to the image carrier, and develops a latent image formed on the image carrier. In an image forming apparatus in which the developer remaining on the body is collected by the collecting means into the developing means and reused, the developing means can be replaced with the developing means in a state where the carrier is collected by the collecting means into the developing means. It is configured.

(Function) In this invention, when it becomes necessary to replace the developing device, first, the collecting device is operated by the control device to collect the developer into the old developing device, and in this state, the old developing device is replaced with the new developing device. By making the developing device replaceable, it is possible to prevent old developer from being mixed into a new developing device.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 4 shows the main parts of an image forming apparatus, such as a laser printer apparatus, to which the present invention is applied. The photosensitive drum 10 is rotated in the six directions indicated by the arrows in the figure, and first, the surface thereof is charged with an electric charge by the charging device 11 . Thereafter, the surface of the photosensitive drum 10 is irradiated with a laser beam LB generated from a laser beam forming section (not shown), and the static 1! A latent image is formed. This electrostatic latent image is developed by applying toner by the developing device 12, and this developed image is transferred to the transfer charger 13.
The image is transferred onto a sheet of paper conveyed as shown by arrow B in the figure, and this sheet is peeled off by a peeling charger 14.

This paper is conveyed to a fixing section (not shown), fixed thereon, and then discharged.

On the other hand, said! Photosensitive drum 1 after 1lli operation
0, the residual toner is removed by the cleaner 15, and then the residual charge is removed by the static elimination lamp 16.

The cleaner 15 includes a screw conveyor 15t that moves the toner in the cleaner 15 to a discharge port 15a, which will be described later.
) is provided.

Here, the photosensitive drum 10 and the cleaner 15 are integrated into a unit, and the developing device 12 is removably attached to this unit.

Next, the current VIi@Hyaku12 will be further explained.

A developing roller 17 that holds developer and rotates is provided inside the developing device 12, and the toner held in this developing roller 517 is transferred to the photoreceptor drum 10, causing an electrostatic phenomenon. ing. A scraper 18 that scrapes off the developer is in contact with the upper portion of the developing roller 17 in the drawing. That is, an elastic member (not shown) is provided at the tip of the scraper 18, and this elastic member is in contact with the surface of the photoreceptor drum 10. The toner scraped off by the scraper 18 is returned to the developer storage section 19 through the upper surface of the scraper 18. The inside of this housing part 19 is partitioned at the center by a partition 119a, and has first and second housing parts 19b119C.
is formed.

Screw conveyors 20 and 21 are rotatably provided inside these accommodating parts 19b and 19c, respectively, and these screw conveyors 20 and 21 are configured to rotate in opposite directions. Therefore, the first
, the developer stored in the second storage portion 19b119G is
The developer is circulated and moved within the first and second storage portions 19a and 19b in a direction perpendicular to the flow of the developer returned from the developing row 517.

On the other hand, the magnetic sensor 22 that detects the concentration of the developer is located, for example, at the center in the longitudinal direction of the screw conveyor 2o, where the developer transported by the screw conveyor 2o and the developer returned from the developing row 517 intersect. It is provided. Therefore, the developer conveyed by the screw conveyor 20 and the developer returned from the developing roller 17 are transferred to the detection surface 22a of the magnetic sensor 22 at this portion.
The concentration detection is highly accurate because it comes in contact with the liquid from multiple directions.

FIG. 2 shows a laser printer device. still,
The same parts as in FIG. 4 are given the same reference numerals.

The IJR1 main body 31 is provided with a cover 32 that can be opened and closed, and when the cover 32 is opened, the photoreceptor drum 10. The cleaner 15 and the developing device 12 are pulled out as a unit, and in this state, the developing bag [
12 can be replaced.

Further, the inner surface of the cover 32 is provided with the cleaner 15.
A recovery device 33 is provided for recovering toner scraped off from the photoreceptor drum 10 by the toner to the developing device 12. This recovery device 33 includes a vibrator 3 that can communicate the discharge port 15a of the cleaner 15 with the supply port 19d provided in the housing section 19 of the discharge device 12 when the cover 32 is closed.
3a is provided. The vibrator 33a is provided with a supply port 33b facing the discharge port 15a of the cleaner 15, as shown in FIG. A discharge port 33c is provided opposite to the output port. Further, a screw conveyor 33d is provided inside the vibrator 33a, and the screw conveyor 33d is rotated by a gear 33e driven by a motor (not shown).

The recovery device 33 having the above configuration includes, for example, the photoreceptor drum 10,
The developing bag @12, the cleaner 15, etc. are operated during the image forming operation, and the cleaner 15 removes the photosensitive drum 1.
The toner scraped off from o is collected into the developing bag N12.

FIG. 1 shows a control circuit of this laser printer device.

A motor drive unit 42 is connected to the control unit 41, and the motor drive unit 42 drives the motor 43a that drives the screw conveyor 33d of the collection device 33, and the cleaner 1.
Motor 43b that drives No. 5 screw conveyor 15b
1 and other parts of the laser printer device, such as a motor 43c, etc., are controlled in operation. Further, an operation panel 44 is connected to the control section 41 .

The operation panel 44 is provided with setting keys (not shown) for setting various operations, and is also provided with a display 45 for displaying the operation status of the setting keys, the lifespan of the developer, and the like. Furthermore, this Ill 111 section 41 has a counter 4.
6 is connected. This counter 46 is for counting the number of copies, for example, and is reset when the developing bag [12] is replaced.

In the above configuration, in a normal copying operation, the photoreceptor drum 10, the developing device 12, etc. are operated by the command from the control section 41 as described above, and the copying operation is performed. The collected toner is collected into the accommodating portion 19 of the developing device 12 via the collecting device 33. At the same time, the counter 46 is operated under the control of the control section 41 to count the number of copies.

On the other hand, when the count value of the counter 46 reaches a preset value indicating the lifespan of the developer, the control section 41 outputs a command signal to the motor drive section 42.
2, the motor 43a of the collection bag W133 and the motor 43b of the cleaner 15 are driven for a predetermined period of time in response to this command signal. Therefore, the toner remaining in the cleaner 15 is collected into the storage section 19 of the developing device 12. Thereafter, the control section 41 displays a message on the display section 45 of the operation panel 44 indicating that the developer has reached the end of its life.

When this display is displayed, the operator should turn on the developing device f.
The f12 will be replaced with a new developing device.

According to the above embodiment, when the developer reaches the end of its life, the cleaner 15 and the collection device 33 are operated by the control D[i41, and the toner remaining inside the cleaner 15 is removed from the developing device 12.
After the developer is collected, a display 45 of the operation panel 44 displays that the developer has reached the end of its life. Therefore, since the developing device is replaced after the old toner remaining in the cleaner 15 is collected into the developing device 12, the toner remaining in the cleaner 15 is not mixed into the new developing device as in the past. , it is possible to prevent changes in the concentration of the developer, to reliably initialize a new developing device, and to accurately detect the concentration thereafter.

Incidentally, in the above embodiment, the case where the present invention is applied to a laser printer has been described, but the present invention is not limited to this, and it is also possible to apply the present invention to, for example, an electronic copying machine.

Furthermore, the lifespan of the developer is determined by detecting the number of copies by the counter 46, and when the number of copies reaches a predetermined value, it is determined that the developer has reached its lifespan; however, the present invention is not limited to this. isn't it.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, when it becomes necessary to replace the developing device, first, the collecting means is activated by the 11111 means to collect the developer into the old yA imaging device. In this state, by making it possible to replace the old developing device with a new developing device, image formation is possible that prevents old developer from mixing with new developer and allows accurate detection of developer concentration. equipment can be provided.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a perspective view showing an image forming apparatus to which this invention is applied, with main parts taken out, and FIGS. 3 and 4. FIG. 3 is a partially cutaway side view, and FIG. 4 is a side sectional view. 12...Developing device, 15...Cleaner, 17...
Developing roller, 22... Magnetic sensor, 33... Collection H
a. 41...control unit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 33e Figure 3

Claims (2)

[Claims] (1) A latent image formed on the image bearing member is developed by a developing means that is detachably attached to the image bearing member, and the developer remaining on the image bearing member is collected by a collecting means into the developing means. 1. An image forming apparatus for reuse, characterized in that the image forming apparatus comprises a control means that allows the developing means to be replaced in a state in which the developer is collected by the collecting means into the developing means. (2) A patent claim characterized in that the control means is operable to replace the developing means after operating the collecting means when it is detected by the developer life detecting means that the developer has reached the end of its life. The image forming apparatus according to item 1.