JPS60146275A - Developing device by one component compound magnetic toner - Google Patents

Abstract

PURPOSE:To peel off temporarily a magnetic toner remaining on a sleeve and to replace it with a new magnetic toner by constituting so that an agitator of a magnetic material is placed in the vicinity of one magnetic pole of a magnet roll, or can be made to contact to it. CONSTITUTION:In a developing device by a one component compound magnetic toner, one part or the whole part of an agitator 8a is constituted of a magnetic material, and also a magnetic pole of a magnetic roll 5 fixed and placed in the inside of a sleeve 6 is placed to as to be opposed, in the adjacent part where the sleeve 6 and the agitator 8a are placed adjacently or contact to each other. This device has not only an action for stirring a magnetic toner 4 by the agitator 8a and carrying it to the sleeve 6 but also an action for replacing the magnetic toner 4 on the sleeve 6 with a new magnetic toner 4, by the agitator 8a constituted of the magnetic material and a magnetic action of a magnetic round bar 9 and the magnet roll 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrostatic latent image developing device, and more particularly, to a developing device for developing an electrostatic latent image using a constituent magnetic toner containing a magnetic material inside the powder toner. The present invention relates to a developing device that performs development.

BACKGROUND OF THE INVENTION A typical conventional developing device for developing an electrostatic latent image using a component-based destructive toner as described above is shown in FIG. 1st
In the figure, 1 is a light guide rli, a sex drum, and 2 is its electrostatic latent image. The developing device is disposed close to a position facing the photoconductive drum 1, and includes a flopper 3 for accommodating the -component magnetic toner 4, and a flopper 3 for accommodating the -component magnetic toner 4.
It has an agitator 8 for agitating and conveying the magnetic toner 4, and a plurality of magnet rolls 5 having magnetism fixed inside, and 101 at the periphery IJJi of the magnet roll 5. A non-magnetic cylindrical sleeve 6 rotatably pivoted and disposed close to the photoconductive drum 1; and a non-magnetic cylindrical sleeve 6 disposed close to the top of the sleeve in order to regulate the magnetic toner 1 on the sleeve. It consists of a blade-shaped regulating member 7. The constituent magnetic toner 4 stored in the hopper 3 is conveyed to the vicinity of the sleeve 6 while being agitated by the rotating agitator 8, and is held on the circumferential surface of the sleeve 60 by the magnetic force of the magnet roll 5. As the sleeve 6 rotates, the amount of magnetic toner carried on the sleeve 6 is regulated to a constant level by the regulating member 7 midway through the development area (the peripheral surface of the sleeve 6 is located on the light-guiding drum 1). (area facing the surrounding surface). The sleeve 6 is rotated in the same direction as the moving direction of the photoconductive drum 1, and is rotated at a speed of 1 to 4 times the rotational speed of the photoconductive drum 10, so that the sleeve 6 is rotated in the same direction as the moving direction of the photoconductive drum 1. The entire electrostatic latent image 2 can be developed using the component-based magnetic toner 4 carried on the above-mentioned IJ-Pro and fed into the development area, and good copy quality can be obtained in the initial stage. .

However, such conventional "one-image devices" have a problem in that copy quality deteriorates when copies are continued for a long time.

OBJECTS OF THE INVENTION It is an object of the present invention to completely prevent deterioration of copy quality, which was a problem with conventional developing devices, and to develop a component-based magnetic material that can provide high quality copy quality over a long period of time. Our goal is to provide a complete toner development device.

Progress of the Invention While investigating the causes of the problems with the conventional developing device described above, the present inventors discovered that the deterioration in copy quality was due to the presence of magnetic toner remaining on the surface of the sleeve 60 that was not developed during development. However, it was discovered that this was caused by the fact that the magnetic toner itself accumulated over time and the quality of the magnetic toner itself deteriorated. Further, as a result of research by the present inventors, in order to completely improve such deterioration in copy quality, it is necessary to apply magnetic toner to the sleeve 6 so as to replace the magnetic toner on the surface of the sleeve 6 with fresh magnetic toner. It is an effective method to supply it, and we have found an effective means for this purpose and have completed the present invention.

In the developing device according to the present invention, a part or all of the agitator is made of a magnetic material, and the sleeve and the agitator are in close proximity to each other. Or, the magnetic poles of the magnet roll fixedly placed inside the sleeve are arranged so as to face each other in the vicinity of the contact area. In addition, the magnetic toner on the sleeve surface is replaced with new magnetic toner by the magnetic force between the agitator made of the magnetic material and the magnet roll.

Moxibustion Flow Side The present invention will now be described in more detail with reference to embodiments shown in the accompanying drawings. For convenience of explanation, the first
The same reference numerals are used for parts having the same functions as those shown in the figures, and the explanation of parts that are the same as those of the conventional device will be omitted entirely.

FIG. 2 shows an entire embodiment of the developing device according to the present invention, and shows only the essential parts of the structure. In FIG. 2, the agitator 8α consists of an arm 10 fixed to a rotating shaft 11, and a magnetic round bar 9 attached to its tip and having a length approximately corresponding to the axial length of the sleeve 6. It rotates around a rotating shaft 11. Further, due to the rotation of the agitator 8α, the magnetic round bar 9 is arranged parallel to and close to the surface of the sleeve 6, and is also close to one magnetic pole (the S pole in FIG. 2) of the developing magnet roll 5. It is structured so that it can be done.

7. Similar to the conventional device 6, a blade-shaped regulating member is disposed close to the upper portion of the sleeve 6 in order to regulate the total amount of magnetic toner on the sleeve 6.

To explain the operation mode, when the magnetic round bar 9 attached to the tip of the agitator 8α is not close to the surface of the sleeve 6, as shown in FIG. Although the toner 4 is conveyed thickly, as shown in FIG. 4, as the agitator 8a rotates, the magnetic toner 4 comes close to the sleeve 6.
The thickness is controlled to be thin. Although the details of this phenomenon are not fully elucidated, the agitator 8
When the magnetic round bar 9 at the tip a approaches one magnetic pole of the magnet roll 5, 1f between the magnet roll 5 and the magnetic round n9
A magnetic field curtain is formed at 8'', and the magnetic toner 4 is arranged according to this magnetic field curtain, and only the magnetic toner 4 drawn out from the gap between the sleeve 6 and the magnetic round bar 9 by the friction of the sleeve 6 is transported. Therefore, it is considered that the magnetic toner layer on the sleeve 6 becomes thinner. Therefore, such a phenomenon occurs when the entire agitator (9 and 10) is made of magnetic material and when the sleeve 6 and the agitator 8
This also occurs when the object a (specifically, the magnetic round bar in FIG. 2) is in contact with the object. As described above, a part of the magnetic toner remaining on the sleeve 6 after development is transferred to the tip of the agitator 8α (the magnetic round bar 9 in the apparatus shown in FIG. 2).
Each time the magnetic toner approaches (or contacts) the sleeve 6, it is replaced with fresh magnetic toner.

In fact, in the device m shown in Fig. 2, a magnetic material (stainless steel) is attached to the tip of the agitator 8a.
The closest distance between the magnetic round bar 9 at the tip of the agitator 8a and the sleeve 6 is 0.2 in total.
mm, and the rotational speed of the agitator was set to l 2 rpηL so that it would come into contact with the magnetic toner on the sleeve 6 at least once during one copy. 10,000 copies were collected using the developing device set under these conditions, and there was almost no deterioration in copy quality, and copies of good quality were obtained.

In the above embodiment, the magnetic material of the agitator gα is stainless steel, which is attached to the tip of the entire arm 10 of the round bar 9, but any magnetic material can be used, and its shape and shape may vary. You can also attach it to Arno 10 in any way you like.

Further, the entire agitator (for example, in the case of the agitator shown in FIG. 2, the round 9 and the arm 10) may be constructed entirely of magnetic material, and the shape of the entire agitator in this case may also be made of a specific shape. It is not limited to. Furthermore, as shown in FIG. 5, a magnetic pipe 12 having a length approximately equal to or less than the axial length of the sleeve is loosely passed through a support shaft 13 fixed to the tip of the arm 10. It is also possible to have a configuration like this. In this case, when the tip end (pipe 12) of the agitator 8b is close to the sleeve, the magnetic pipe I2 may be placed in contact with the sleeve due to the magnetic force of the magnet roll inside the sleeve. That is, since the magnetic pipe 12 can freely change its position around the support axis I3, it is in its most extended state when it is closest to the sleeve.

The higher the magnetic force of the magnetic pole of the magnet roll 5, the better;
It is preferably 0 Gauss (9 au, ss) or more, preferably 500 Gauss or more. The distance between the agitator tip and the sleeve is preferably set to 0.5 mm or less, more preferably 0.1 to 0.3 mm.

Effects of the Invention As described above, in the developing device according to the present invention, part or all of the agitator is made of a magnetic material, and the sleeve is provided in the vicinity where the sleeve and the agitator come into close proximity or contact with each other. Since one magnetic pole of the magnet roll fixedly placed inside is arranged so as to face each other, the agitator transports the magnetic toner to the location where the sleeve is located while stirring the entire magnetic toner, and the tip of the magnet roll touches the sleeve surface. When rotating upward and coming into contact with each other, the magnetic force between the magnet roll and the magnetic agitator and the cleaning action of the agitator temporarily strip off the magnetic toner remaining on the sleeve 9 and create new magnetic toner. It can be replaced with toner. Therefore, stable and high-quality copy quality can always be maintained.

However, the above-mentioned exchange action by the device of the present invention is mainly based on magnetic force, and the magnetic toner on the sleeve is not peeled off by strong mechanical force, so there is less damage to the sleeve. As a result, in combination with the above-mentioned effects, copies of good quality that are stable over a long period of time can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a conventional developing device, FIG. 2 is an explanatory diagram of essential parts showing an embodiment of the developing device of the present invention, and FIGS. 3 and 4 are diagrams explaining the operation of the developing device of the present invention. , FIG. 5 is a partial side view showing another embodiment of the agitator of the developing device of the present invention. 1... Photoconductive drum, 2... Electrostatic latent image, 4...
Magnetic toner, 5... Magnet roll, 6... Sleeve, 7... Regulating member, g, 3a,, 8b... Agitator 19... Magnetic round bar, 12... Magnetic pipe. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto 1 excluded

Claims (1)

[Claims] A hopper for accommodating component-based magnetic toner, an agitator disposed within the hopper for agitating and transporting the toner, and a plurality of magnetic rolls fixed inside, and In a developing device using component-based magnetic toner, which includes a non-magnetic cylindrical sleeve rotatably fixed around the magnet roll, and a regulating member for regulating the amount of magnetic toner on the sleeve, the agitator A component-based magnetic toner developer, characterized in that part or all of the sleeve and the agitator are arranged in close proximity to or in contact with each other so that the magnetic poles of the magnet roll face each other. Device.