JPS5865460A - Developing device - Google Patents

Abstract

PURPOSE:To obviate the irregular density of pictures by disposing two agitating members which are supported freely rotatably in the vessel of a developing device in such a way as to transfer the toner in the vessel in a prescribed direction. CONSTITUTION:Agitating bars 32, 33 consist of vanes 201, 202, 201', 202' attached on both sides of circular cylindrical bars 200, 200', which vanes 201, 202, 201', 202' are twisted right-hand and left-hand and are joined in the central parts. When the twisting pitch of the vanes 201, 202 of the bar 32 is defined as L1 and the vanes 201', 202' of the bar 33 as L2, the pitches are set at L2<L1. The toner and developer in a vessel 30a are moved to the central part of the member 32 by the rotation of the member 32, and the toner and developer in the vessel 30a are moved to both side parts of the member 33 by the rotation of the member 33.

Description

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

The electrostatic latent image on the photosensitive drum is visualized by a developer. The developing device is composed of a magnet roll and stirring means. The developer consists of carrier and toner. The carrier is mainly made of iron powder, and the surface is coated with an oxide film or a polymer. Toner is a colored polymer powder. When the carrier and toner are mixed and stirred, they rub against each other 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. 1 shows 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 1o made of amorphous selenium rotates in the direction of an arrow 11. A positive high voltage is applied to the charger 100 to give a positive charge to the drum. Original 11o is mirror 111.11
2, 113, 114, 115, 116, lens 117
, are imaged onto the photosensitive drum 1o through the slit 118, forming an electrostatic latent image. The developing device 30 contains the developer, and the developer is rubbed onto the surface of the photosensitive drum 1o by a magnet roll 31 consisting of a magnet disposed within a non-magnetic tube 17 to visualize the electrostatic latent image. . At this time, only the toner adheres to the photosensitive drum 1o, and the carrier remains in the developing device 3o. If development is repeated many times, the toner in the developer decreases, so new toner must be replenished. New toner is supplied by Hon/Nee SO. At this time, it is necessary to mix the toner and the toner vigorously, and the mixture is stirred using stirring rods 32 and 33.

The toner adhering to the photosensitive drum 1o is transferred to the transfer charger 1.
01 to be transferred to paper. A separating charger 102 separates the paper from the photosensitive drum 10, and a fixing device 130 heats and pressurizes the paper to fix it, thereby forming a copy. The photosensitive drum 1o is neutralized by a static eliminating section 103, and then removed by a cleaner section 120.
is cleaned and the copying process ends.

Toner is consumed within the developing device 30, and new toner is repeatedly replenished. When new toner falls into the developing device 3o from the hopper 60, a sufficient charge is applied to the toner by frictional charging due to appropriate stirring, thereby reducing the scattering of the toner to the outside. If the stirring is inappropriate, the image will deteriorate and more toner will scatter outside the developing device 30.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that causes less toner scattering and does not cause image density unevenness 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 a developing device of the present invention as described above, and FIG. 2 is a perspective view showing a portion of a developing device unit according to the present invention. The developing device unit is located on the front side plate 35. A magnet roll 31 is attached to the rear side plate 36. First and second stirring rods 32 and a 33° drum fixed shaft 12. Cleaning section 1
Consists of 20. Here, the magnet roll 31. The part equipped with stirring rods 32 and 33 is called the developing device 3o.
The magnet roll 31 is fixed by a roll fixing knob 37. The first and second stirring bars 32,33 are provided with first and second gears 38,39. The developing device 30 is covered with a lid 4o.

Is the photosensitive drum 1o the drum fixed shaft 1? The drum fixing knob 11 and drum fixing pin 13 are used to attach the drum to the developing unit.

FIG. 3 is a sectional view of the developing device 3o and the photosensitive drum 10.

The developer is mixed by the stirring rods 32 and 33, and comes out from between the magnet roll 31 and the drum blade 450 and is applied to the photosensitive drum 1.
Rub the surface of 0. The developer after development is scraped off by a scraper 41. New toner is in the hopper SO, and is introduced into the developing device 3° through the toner receiving port 34 by the supply roller 61. A seal 66 is provided to prevent toner from leaking from the gap between the hopper 60 and the developing device 3o. A plate 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. Stirring bar 32 is rotating in the direction of arrow 43, and stirring bar 33 is rotating in the direction of arrow 44.

Note that the stirring member 32 is connected to the container 30a of the main body of the developing device.
is rotatably disposed below a toner receiving port 34 to which toner is supplied from a hopper 60 provided at the top of the
The stirring member 33 is rotatably disposed below the stirring member 32. Further, the plate 42 having an L-shaped cross section is arranged in the container 30a so that its lower plate portion is located below the stirring member 32.
installed on the inner wall of the

FIGS. 4(a) and (b) show the stirring rod 32,
33, and FIG. 6 is a sectional view taken along the line AA′ in FIG. 4(a). Furthermore, this sixth
The cross-sectional shape of the figure is the same as that of FIG. 4 Φ). The stirring rods 32, 33 have blades 201, 202, 201', 202' on both sides of cylindrical rods 200, 200', respectively, and these blades 201, 202, 201', 202
' is twisted into cloth wrapping and left wrapping and connected at the center.

Note that such spiral wings 201 , 202 , 20
1'.

202' do not necessarily need to be connected at the center. Further, here, the stirring rod 32 is referred to as a first stirring rod, and the twisting pitch of its blades 201 and 202 is Ll. Further, the stirring bar 33 is referred to as a second stirring bar, and its blades 2
Torsional pitch L2 of 01', 202' (however,
The relationship is set as L2<L,).

6 and 7 are cross-sectional views showing other examples of the first and second stirring rods 32 and 33 that can be used in the present invention, and in the case of FIG. FIG. 7 shows a cylindrical bar 200 with four wings 204 to 20.
7.

FIG. 8 shows the flow of toner and developer by the stirring rod in the present invention. First and second stirring rods 3
2.33 are interlocked and rotated by gears 38.39.

Toner falls from the hopper in the direction of arrow 62. 1st
The toner that falls due to the movement of the stirring rod 32 is shown in the arrow 63.
move in the direction of at a speed of vl. That is, it moves to the center of the developing device 30. The developer that has been sufficiently stirred and mixed in the center is moved in the direction of the arrow 64 by the action of the second stirring rod 33.
Move at a speed of 2. The torsional pitch of the blades 201, 202 of the first stirring bar 32 as described above.

The torsional pitch of the blades 201' and 202' of the second stirring bar 33 is L2, and since Ll>L2, the rotation speeds of the first and second stirring bars 32 and 33 are the same. If the gears 38 and 39 are selected so that the toner and developer move speeds become vl>v2. Therefore, the fallen toner is rapidly collected in the center of the developing device, and given sufficient stirring time, slowly moves to both ends of the developing device.

The developer is attracted to the magnet roll 31 while moving in the direction of the arrow 64 and participates in development.

Generally, toner scattering is more likely to occur in a developer in which toner and carrier are not well mixed, and toner scattering is more likely to occur from both ends of the magnet roll 31. According to the present invention, a state in which the toner is not sufficiently mixed with the carrier;
In other words, in the state of the toner immediately after falling from the bomber 60, the action of the first stirring rod 32 causes the toner to be transferred to the developing device 3.
The developer gathered at the center of the magnet roll 31 and sufficiently stirred and mixed at the center spreads toward both ends by the action of the second stirring rod 33, and toner scattering at both ends of the magnet roll 31 is greatly reduced.

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

FIG. 9 shows the rear side of the present developing device, in which the first stirring rod 32 is connected to a drive means (not shown) through a gear 48 and rotates in the direction of an arrow 43.

The sleeve of the magnet roll 31 is rotated in the direction of an arrow 46 by a gear 47.

FIG. 10 shows the front side of this developing device, and the first stirring rod 32 rotated by the driving means is connected to the gear 3.
8 and gear 39 to rotate the second stirring rod 33 in the direction of arrow 44. The magnet in the sleeve of the magnet roll 31 is fixed to the knob 37 on the front side.

As is clear from the above description, the developing device of the present invention causes less scattering of toner in the developer, and also does not cause image density unevenness due to unevenness of the developer, making it possible to copy images favorably. It is something.

[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 according to an embodiment of the present invention, and FIG. 4(a) and 4(b) are external views showing an example of the first and second stirring rods used in the present invention, and FIG. AA' line sectional view of the figure, Figures 6 and 7
The figure is a sectional view of another embodiment of a stirring bar that can be used in the present invention.
Fig. 8' is a sectional view of main parts showing the 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 The figure is a front view of the developing device according to the embodiment of the present invention. 3o...Developer, 30a...Group/container, 3
1...Group/Magnetic Rope Nope 32...First stirring bar, 33...Second stirring bar, 34'...
...Toner intake port, 38°39...Gear, 6
o...Hopper, 200, 200'...
Cylindrical rod, 201, 201', 202, 202', 203
~207 ...wings. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 0 6th N First Figure 7 0 Mouth 425-

Claims (1)

[Claims] a developing device container having a toner receiving port into which toner is supplied from a hopper; a magnet roll rotatably supported within the container; and first and second stirring members; disposing a member below the toner receiving port;
The second stirring member is configured to be disposed below the first stirring member, and the first and second stirring members are arranged on the Ishinomaki and left sides in each half from the center to the end of the rotating shaft. The first stirring member has a structure in which spiral blades are provided, and the pitch of twist of the spiral blades of the first stirring member is Ll, and the pitch of twist of the spiral blades of the second stirring member is L2. In this case, the relationship Ll>L2 is set, and the first stirring member rotates within the container so as to move the toner and developer in the container to the center of the stirring member, and the second stirring member A developing device characterized in that the agitating member rotates so as to move the toner and developer in the container to both ends of the agitating member.