JPS58186764A - Developing device - Google Patents

Abstract

PURPOSE:To generate uneven density of a picture, which is caused by deflection of a developer, to make it uniform extending over the whole face of a copy, and to copy a picture satisfactorily, by constituting so that quantity of the developer carried in front of a developing device is made relatively smaller than that which is carried into the inner part of the developing device. CONSTITUTION:A developing device 30 contains said developer, and the developer is rubbed and applied against the surface of a photosensitive drum 10 by a magnet roll 31 which provides a magnet in a non-magnetic sleeve, by which an electrostatic latent image is made visible. In this case, only a toner adheres onto the photosensitive drum 10, and a carrier remains behind in the developing device 30. When the development is repeated again and again, the toner in the developer is reduced, therefore, a new toner is replenished from a hopper 60. In this case, since it is necessary to severely mix the carrier and the toner, they are stirred by stirring rods 32, 33. The toner which adheres onto the photosensitive drum 10 is transferred on paper by a transfer charger 101. The paper is separated from the photosensitive drum 10 by a separating charger 102, is heated, pressed and fixed by a fixation device 130, and a copy is obtained. The photosensitive drum 10 is destaticized by a destaticizing part 103, and is cleaned by a cleaning part 120.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device used in an electronic copying machine.

The electrostatic latent image of the photosensitive i-lamt is visualized by a developer. The developing device is composed of a magnet roll and stirring means. The developer consists of a gear and a gear. The carrier is mainly composed of iron powder, and the surface is coated with an oxide film or a polymer. 1.S- is a colored polymer powder. When carriers A and 1.S- are mixed and stirred, they are strongly rubbed and become electrically charged. When amorphous selenium is used for the photosensitive drum, the toner and carrier are selected so that the toner has a negative charge and the carrier has a positive charge.

FIG. 1d is an embodiment of an electronic copying machine according to the present invention,
The basic process of an electronic copying machine will be explained using this diagram.

A photosensitive drum 10 made of amorphous selenium rotates in the direction of an arrow 11. Apply a positive high voltage to the charger 100 and apply a positive voltage to the drum. Original 1103 mirrors 111, 112, 113, 114, 116, 1
16. An image is formed on the photosensitive drum 10 through a lens 117 and a slit 118, forming an electrostatic latent image. Developing device 3o
contains the developer, and the developer is rubbed onto the surface of the photosensitive drum 1o by a magnet roll 31 comprising a magnet disposed inside a non-magnetic sleeve to visualize the electrostatic latent image. At this time, only the toner adheres to the photosensitive drum 10 and the carrier remains in the developing device 30. If development is repeated many times, the toner in the developer decreases, so new toner must be replenished. New toner is replenished from hopper-eo. At this time, it is necessary to mix the carrier and toner vigorously, and the mixture is stirred using stirring rods 32 and 33.

The toner adhering to the photosensitive drum 10 is transferred to a transfer charger 1.
01 can be transferred to paper. The separation charger 102 separates the paper from the photosensitive drum 10, and the fixing device 130 heats and pressurizes the paper to fix it, resulting in a copy. The photosensitive drum 10 is neutralized by the static eliminating section 103 and cleaned by the cleaner section 120, and the copying process is completed.

Toner is consumed within the developing device 30, and new toner is repeatedly replenished. When new J. toner falls from the hopper 60 into the developing device 30, sufficient electric charge is applied to the toner by frictional charging caused by appropriate stirring. If this stirring is inappropriate and the amount of developer in the container of the developing device 30 is uneven, uneven image density will occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that does not cause unevenness in image density due to unevenness of developer.

Examples of the present invention will be described below. FIG. 1 is a sectional view of a main part of an example of an electronic copying machine incorporating the developing device of the present invention as described above, and FIG. 2 is a perspective view showing a portion of the developing device unit according to the present invention. The developing unit is located on the front side plate 36. A magnet roll 31 is attached to the rear side plate 36. First and second stirring rods 32 and 33, drum fixed shaft 12. Cleaning section 1
205, H, -J゛.

The magnet roll 31 is fixed by a roll fixing knob 37. The first and second stirring rods 32 and 33 are provided with first and second gears 38 and 39, respectively. The developing device 3o is covered with a lid 4o. The photosensitive drum 1o is attached to the developing device unit by a drum fixing shaft 12, a drum fixing knob 11, and a drum fixing bin 13.

FIG. 3 is a sectional view of the developing device 30 and the photosensitive drum 1o. The developer is mixed by the stirring rods 32 and 33 and comes out from between the magnet roll 31 and the doctor grade 46 to rub the surface of the photosensitive drum 10. The developer after development is scraped off by a scraper 41. New toner is in the pumper 60 and is introduced into the developing device 3° through the toner receiving port 34 by the replenishment roller 61. Tonneau has hopper 60 and developer 3
A seal 66 is provided to prevent leakage from the gap o. A plate 6 42 having an L-shaped cross section is provided to prevent the fallen toner from entering the lower part of the developing device 30 as it is. The stirring rod 32 is rotating in the direction of arrow 43, and the stirring rod 33 is rotating in the direction of arrow 44.

Note that the stirring member 32 is connected to the container 30 a of the main body of the developing device.
The agitation member 33 is rotatably disposed below the toner receiving port 34 to which toner is supplied from a hopper 60 provided at the top of the agitation member 32 . -! In addition, the plate 42 having an L-shaped cross section is arranged so that the lower plate part thereof is located below the stirring member 32.
It is attached to the inner wall of a.

FIG. 4 shows the stirring rods 32, 33.

FIG. 6 is a sectional view taken along line A-A/ in FIG. 4. Stirring rod 3
2 and 33 have blades 201 and 202 on both sides of the cylindrical rod 200, and the height of these blades is equal to the height of the blade of the first stirring rod 32 H1 The height of the blade of the second stirring rod #33 The configuration is such that H>h, where h is h.

FIGS. 6 and 7 show a stirring bar 32 that can be used in the present invention,
33, in the case of FIG. 67-1, one wing 203 is provided on a cylindrical rod 200, and in FIG.
7.

Figure 8 shows the flow of toner and developer by the stirring rod in the present invention.
It rotates in conjunction with 8.39.

The toner falls from the hopper in the direction of arrow 62.
The toner that fell off due to the action of the stirring rod 32 is shown by the arrow 63.
move in the direction of That is, it moves toward the back of the developing device 3o. The toner and carrier mixed by the first stirring rod 32 are moved in the direction of the arrow 64 by the action of the second stirring frame 33 .

That is, it moves to the front of the developing device 3o.

The developer that has fallen to the bottom of the developing device in this way is attracted to the magnet roll 31 and takes part in the development.

Generally, since the rotational speed of the two stirring rods 32 and 33 is equal, the amount of developer transported to the front of the developing device is larger than the amount transported to the back of the developing device, resulting in so-called developer bias, which is caused by the image density. It appears as unevenness.

However, according to the present invention, the amount of developer carried to the front of the developing unit can be made relatively smaller than the amount carried to the back of the developing unit, so that it is possible to eliminate developer clumps, and image The density is also uniform over the entire surface of the copy, which is effective in improving copy quality.

As shown in FIG. 3, the plate 42 having an L-shaped cross section prevents the toner falling from the hopper from reaching the stirring rod 33 due to insufficient mixing.

Figure 9 shows the rear side of this developing device, and the stirring rod 3
2 is connected to a drive means (not shown) by a gear 48 and rotates in the direction of arrow 43. The sleeve of the magnet roll 31 is rotated in the direction of an arrow 46 by a gear 47.

FIG. 1o shows the front side of the present developing device, and the stirring rod 32 rotated by the driving means rotates the stirring rod 33 in the direction of arrow 44 through gears 38 and 39. The magnet in the sleeve of the magnet roll 31 is fixed on the front side by a knob 37.

9-- As is clear from the above description, the developing device of the present invention can make the image density uniform over the entire surface of the copy without causing uneven image density due to unevenness of the developer, and can achieve good image copying. It is what makes it possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of an example of an electronic copying machine incorporating a developing device of the present invention, FIG. 2 is a perspective view of a developing device unit that is an embodiment of the present invention, and FIG. A sectional view of a developing device and a photosensitive drum according to an embodiment, FIG. 4 is an external view showing an example of a stirring bar used in the present invention, and FIG.
6 and 7 are cross-sectional views of other embodiments of the stirring rod that can be used in the present invention, and FIG. 8 is a flow of toner and developer in the developing device according to the embodiment of the present invention. FIG. 9 is a rear view of the developing device according to the embodiment of the present invention, and FIG. 10 is a front view of the developing device according to the embodiment of the present invention. 30...Developer, 30a...Container, 3
1... Magnet roll paper 32.33...
・Stirring bar, 10 pages 34...-... Toner receiving port, 38.39...
- Gear, 6o... - Hopper, 2oo... cylinder a, 201-207... wing. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Fig. 40 Fig. 5 Fig. 6 Fig. 7 Fig. 7 06 Co C'). C ■ -1

Claims (1)

[Scope of Claims] A developing device container having a toner receiving port into which toner from a honohar is supplied, a magnet roll rotatably supported within the container, and first and second stirring parts. 1~,
The first stirring member is disposed on the F side of the toner receiving port, and the second stirring portion 4=A is arranged below the first stirring member. The second stirring member has a structure in which spiral blades are provided from one end to the other end 4, and the first stirring member moves the developer from one end of the container to the other. the second stirring member rotates within the container so as to move the toner and developer in the container to the other end of the container; A developing device characterized in that the height of the blades of the first stirring member H is H1 and the height of the blades of the second stirring part H is h, and the relationship H>h holds. 2 par'