JPS5857166A - Magnetic brush developing device - Google Patents

Abstract

PURPOSE:To prevent defects carrying a magnetic developer with an easy operation to form a vivid image, by providing a scraping means which scrapes matters stuck to the tip part of a doctor blade. CONSTITUTION:A guide rod 24 is laid on side frames 12A and 12B near a doctor blade 19, and this guide rod 24 is provided with a moving member 25 which is moved back and forth freely in the axial direction. One end part of a scraping member 26 which has the other end part inserted into a guide groove 20 provided in the first casing 11A and consists of nonmagnetic materials is fixed to this moving member 25 by a proper means. A hook part 27 of the scraping member 26 is engaged with a tip part 19a of the doctor blade 19 and is moved along the tip part 19a of the doctor blade 19 to scrape a magnetic toner 13 stuck to the tip part 19a. In another method, a scraping member consisting of a scraping plate consisting of nonmagnetic materials and a fixed member is moved back and forth.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic brush developing device using a nine-component magnetic toner.

A magnetic brush developing device is used in electrophotographic mounting and electrostatic recording devices, and this magnetic brush developing device is constructed as shown in FIG. That is, in the same figure,
The magnetic brush developing device 1 includes a developing roller 2, a doctor blade 5, a magnetic developer such as -component magnetic toner 4, and a housing 5, and a 1gl carrier (hereinafter also referred to as a photosensitive drum) 6.
The developing roller 2 is disposed along the axis of the photosensitive drum 6 and spaced from the circumferential surface of the photosensitive drum 6 by a predetermined distance. Further, the scooping image roller 2 is composed of a sleeve 2A and a magnet 2B, and is configured such that at least one of the two sleeves or a magnetic field generating means, such as the magnet roller 2B, is rotated by an appropriate drive device. And 1
! ! The one-component magnetic toner 4 stored in the body 5 is attached to the developing roller 2 rotating in the direction of the arrow in the figure by static electricity or magnetic force, and the one-component magnetic toner 4 attached to the developing roller 2 is moved by the doctor blade 3. After the amount is adjusted, the magnetic toner 4 is transferred to the vicinity of the photosensitive drum 6 as the developing roller 2 rotates. Next, the magnetic toner 4 is attracted to an electrostatic latent image formed by charges distributed on the photosensitive drum 6 by electrostatic attraction, and development is performed.

However, in this type of magnetic brush developing device, the gap between the doctor blade 5 and the two sleeves of the developing roller 2 is C.
L2~1. Because it is formed extremely narrowly, foreign matter such as fixed magnetic toner may get stuck between the doctor blade and the sleeve 2m of the developing roller 2, or magnetic toner may adhere to the tip fi of the doctor blade. As a result, the gap between the doctor blade and the sleeve narrows, reducing the amount of magnetic toner conveyed, resulting in image unevenness, and in severe cases, the area becomes white and the image becomes unclear. .

This invention has been made based on the above circumstances, and it is possible to prevent poor conveyance of magnetic developer with a simple operation, form a clear image, and has an extremely simple structure. It is an object of the present invention to provide a highly reliable magnetic brush developing device. , 'This invention will be described with reference to an embodiment shown in the drawings.

FIG. 2 is a longitudinal sectional front view showing an embodiment of the magnetic brush developing device of the present invention, and FIG. 3 is a perspective view of the main parts. In each figure, 10 is a magnetic brush developing device, and this magnetic brush developing device 10 has a first casing 11 and a second casing 11B facing each other, and each casing 11
A pair of side frames 12A at both longitudinal ends of the frame 11B
, 12B are attached, and a magnetic developer (hereinafter also referred to as component magnetic toner) 13 is attached to the upper end.
A supply opening 14 is configured for supplying.

Further, a developing opening 15 is formed at the lower left end. Inside the frame 160 configured in this way, there are a magnetic toner storage section 17 and a current (IJ! roller storage section 18).
is made up of. Note that the first casing 11
A doctor blade 19 is integrally formed with the tenth casing 11A at the corner portion of the doctor blade 19, and an eastward groove 20 is formed on the lower side of the doctor blade 19. The purpose of this doctor blade 19 is to uniformize the -13 violet of magnetic toner conveyed by a moving member (hereinafter also referred to as a developing roller) 21, which will be described later. The developing roller 21 includes a cylindrical rotating body (hereinafter also referred to as a sleeve) 22 made of a non-magnetic material such as aluminum, and a magnetic field generating means (hereinafter also referred to as a magnet roller) 23 disposed inside the sleeve 220 and the like. At least one of the sleeve 22 and the qf net roller 23 is configured to be rotated by an appropriate drive device,
The magnetic toner 13 is conveyed to a photosensitive drum 29. The magnet roller 23 has H poles and 8 poles arranged alternately at equal intervals in a multi-pole ring shape, so that substantially upright lines of magnetic force are formed on the outer surface of the sleeve 22.

Further, a guide rod 24 is installed on the side frames 12A and 12B close to the doctor blade 19.
A moving member 25 is disposed on the guide rod 24 and is capable of reciprocating along the axial direction.
A guide groove 2 is provided at one end in the first casing 11.
The other end of the scraping member 26 made of a non-magnetic material (7 plates are shown in the figure, but may be made of a wire material with elasticity) inserted into the It is fixed by means. Also.

One end of this scraping member 26 is bent upward to form a hook portion 27, and the hook portion 27 of this scraping member 26 engages with the tip 19a of the doctor blade 19. Tip part flaK of doctor blade 19
The tip portion 191L is configured to move along the magnetic toner 191L and scrape off the attached magnetic toner 13. Matoko+
One end of an operating rod 28 is attached to the moving member 25, and the other end of the operating rod 28 penetrates a hole 12a provided in the side frame 12B and projects to the outside. As a result, by operating this protruding portion, the scraping member 26 is reciprocated to clean the tip 19a of the doctor blade 19. The scraping plate 26 is preferably formed of an elastic non-magnetic material plate having a width of 10 mm and a thickness of 0.061 Lii, for example. Note that the guide rod 24° has been moved to IJJJ member 25. Scraping member 26. The operating rod 28 constitutes a scraping means.

The scraping plate 26 configured as described above is set on one side frame 12 when the magnetic brush developing bag [10] is operated, so that it does not adversely affect one image. On the other hand, when the doctor blade 19 is clogged with foreign matter such as fixed magnetic toner or paper waste, or when the doctor blade 19
When the gap narrows due to the magnetic toner 13 adhering to the tip 19a of the side frame 12B, and during regular inspections, the operator grasps the operating rod 28 that protrudes through the hole 12a provided in the other side frame 12B with a cow. and move it in the direction of arrow A.

When the operating rod 28 is moved, the moving member 25 attached to one end of the operating rod 28 moves along the guide rod 24.
Scraping member 26 attached to this transfer 1jIIJ member 25
The hook on the other end? 7 is the tip 1 of the doctor blade 19
9aK? Magnetic toner 15 moving and adhering to Ej
This means scraping off the particles or removing stuck magnetic toner, paper waste, etc. that are stuck in the gap between the doctor blade 19 and the sleeve 22. After use, the movable member 25 is moved toward the side frame 12 and set.

4 and 5 are a side view and a longitudinal sectional front view showing another embodiment of the magnetic brush developing device of the present invention, in which the doctor blade 19 is made of a non-magnetic material along the inner wall surface. A scraping member 26A consisting of a scraping plate and a fixing member is configured to reciprocate. This scraping member 26m is formed to have approximately the same length as the doctor blade 19, and is attached to the side frame 12.
It is designed to be guided by 30B and the inner wall surface of the doctor blade 19 to the guide plate 30 attached to 2BK. Pins 31A and 51B are provided on both sides of the scraping member 26A.
The pin 51 is provided with a protruding pin 51B, which passes through an elongated hole 120 provided in the side frame 112 at 12B, and its end protrudes outward. 31 to this pin 51
One end of the protruding part B is attached to the side frames 12A, 12.
The other end of the biasing member 52B is attached to a spring 52, for example, which is attached to the biasing member 1B, and the springs 52A and 32B push the tip of the scraping member 26m toward the doctor blade 19.
is biased in the direction away from the tip end 19 & of the. Also.

A drive member 33B, for example, a solenoid 35, is attached to the protruding portion of 31B to the pin 51, and a scraping portion,
The material 26m is moved to the spring 32 against the biasing force of 32B, and the tip of the scraping member 26m protrudes from the tip 91% 19a of the doctor blade 19 to scrape off the attached magnetic toner 13. That will happen. Note that the driving member may be configured to reciprocate through a cam or the like instead of a solenoid. In other respects, the configuration is almost the same as that of the embodiment described above, so a detailed explanation thereof will be omitted.

Also, 31B to the pin 51, spring! S2A, 32B, drive members 33A, 53B, etc. constitute a scraping means.

The scraping plate 26A of the magnetic brush developing device [10] configured as described above has 33B cut off to the solenoid 55 and 52 cut off to the spring 32 when the magnetic brush developing device tID is operated.
It is urged by the urging force of B, and the scraping member 26
The tip of the doctor blade 19 is located at an upper portion separated from the tip 19a of the doctor blade 19. on the other hand.

When 33B is activated to solenoid 33 when the gap becomes narrow due to adhesion or during periodic inspection.

Pin 3 attached to the operating part of 33B to this solenoid 33
1 31B moves in the direction of the arrow against the urging force of springs 32A and 32B. Therefore, the scraping member 26M with 31B attached to this pin 31 moves along 30B to the inner wall surface of the doctor blade 19 and the guide plate 50, and the tip of the scraper 26A moves to the tip 1 of the doctor blade 19.
The tip 19a of the doctor blade 19 protrudes from 9a.
This means scraping off the magnetic toner 13 adhering to the surface.

Next, when solenoid 53m and 33B are released, pin 3
1 to 31B is pulled upward by the biasing force of the springs 32A and 32B, and thereby the scraping member 26m is also pulled up and its tip is positioned above the tip 19a of the doctor blade 19 and stands by. becomes. With this configuration, it can be done automatically,
This has the advantage of not requiring work such as a service call.

Note that each of the above embodiments is merely an example.

It goes without saying that each member can be replaced with another member having the same ability.

Since this invention is constructed as described above, a magnetic developer is fixed between the doctor blade and the snub.

Even if the gap is narrowed due to foreign matter such as paper scraps or magnetic developer adhering to the tip of the doctor blade, this can be removed with a simple operation, resulting in clear images. You can get the image. Moreover, the structure is extremely simple, and it has excellent effects such as being able to supply highly reliable products at low cost.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional front view showing an example of a conventional magnetic brush developing device, FIG. 2 is a vertical sectional front view showing an embodiment of the magnetic brush developing device of the present invention, and FIG. 3 is a perspective view of main parts. Fourth
The figure is a side view showing another embodiment of the magnetic brush developing device of the present invention, and FIG. 5 is a longitudinal sectional side view of the same. 10...Magnetic brush developing device, 15...Magnetic toner. 24... Guide rod, 25-7y moving member, 26
．． 26... Scraping member, 27... Hook portion, 28...
・Operation rod, 31B to 31...Pin, 32B to 32...
・Spring, 33A, 55B... Solenoid Figure 1 Figure 2 Figure 4 Figure 3 25 128 Figure 4 Spear Figure 5

Claims (1)

[Scope of Claims] +11 In an apparatus for developing an electrostatic latent image using magnetic development, a moving member comprising a magnetic field generating means and supplying the magnetic developer to the electrostatic latent image while adsorbing the magnetic developer. The device includes a doctor blade for regulating the bar of magnetic developer attracted to the moving member, and a scraping means for scraping off deposits on the tip of the doctor blade. A magnetic brush developing device characterized by the following features. (21) The scraping means is moved along the free end of the doctor blade, which is the free end of the scraping member, via a moving member attached to a guide rod. The magnetic brush developing device according to Item 1. (31) The scraping means is driven by a drive member, and the scraping member moves along the inner wall surface of the doctor blade. 1st
The magnetic brush developing device described in . +41 The magnetic brush developing device according to any one of claims 1 to 3, wherein the scraping member of the scraping means is formed of a non-magnetic material.