JP2536026Y2 - Dry electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dry electrophotographic apparatus for visualizing a latent image on a photoreceptor using a powdery developer.

[Conventional technology]

For example, a dry two-component developing device of a copying machine includes a developer tank and a toner tank (toner hopper), and a detachable and replaceable toner cartridge containing toner is mounted in the toner tank. The toner is taken out of the developer tank by an agitator and supplied to the developer tank.

In the developer tank, a developer composed of toner and a carrier is stored. The developer is transported onto a photoconductor by a developing roller, and the latent image formed there is visualized. Is becoming

[Problems to be solved by the invention]

However, in such a conventional dry-type two-component developing device, the toner in the toner tank easily deteriorates in fluidity due to a change in environment such as humidity. Therefore, for example, the toner supply amount is usually 10 g / mim in normal times. However, at high humidity 3g / mi
There was a problem that it could be drastically reduced to m.

The same applies to the inside of the developer tank, and when the humidity is high, the fluidity of the developer deteriorates, and the passage of the developer on the TS sensor, which controls the concentration of the developer, deteriorates. There has been a problem that the density control cannot be performed properly, and a problem may occur in the stirring property of the developer.

The present invention has been made in view of the above problems, and has as its object to prevent various problems caused by deterioration of fluidity of powdery toner at high humidity.

[Means for solving the problem]

In order to achieve the above object, the present invention includes a toner cartridge containing a powdery toner used for visualizing a latent image on a photoreceptor, and is provided inside the toner cartridge. In a dry electrophotographic apparatus, a toner delivery fin is fixed to a rotating shaft, and the toner delivery fin is rotated in the toner cartridge by rotation of the rotating shaft, so that toner is sent out of the toner cartridge. A desiccant is attached to the toner delivery fin with a predetermined length from the vicinity of the rotation axis toward the tip of the toner delivery fin.

[Action]

According to the dry electrophotographic apparatus configured as described above, the desiccant is attached to the toner delivery fin that rotates in the toner cartridge, so that the toner cartridge is dried substantially uniformly over the entire area by the desiccant. As a result, it is possible to prevent deterioration of the fluidity of the toner, which is generated in a high-humidity environment.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a block diagram showing a developing device of a copying machine as a dry electrophotographic apparatus to which the present invention is applied, and FIG. 2 is a schematic diagram showing the entire copying machine.

This copying machine is also capable of performing color copying. As shown in FIG. 2, a color original set by opening and closing a pressure plate 3 on a contact glass 2 arranged on an upper surface of a copying machine main body 1. D is repeatedly scanned by the scanning optical system 20 to sequentially perform multiple-color separation exposure on the photosensitive drum 14 rotating at a constant speed, and the latent image formed on the photosensitive drum 14 After developing with a complementary color toner to produce a visible image,
Transfer paper P, which is fed from the printer and is clamped and held on a transfer drum 15 which rotates in the direction of the arrow in contact with the photosensitive drum 14,
The toner image is repeatedly transferred.

Around the photosensitive drum 14, a charged charger 16,
Developing devices 4, 5, 6, and 7 for various color copies, a transfer charger 18, a cleaning device 19, and the like are provided.

The scanning optical system 20 includes a lamp 21, a plurality of mirrors 22,
a to 22d, an imaging lens 23, and the like. Each of these components can reciprocate between a position shown by a solid line and a position shown by a virtual line in FIG.
A color separation filter 24 is provided in the optical path.

Therefore, in this copying machine, the color original D is repeatedly scanned by the scanning optical system 20, thereby sequentially performing the multiple color separation exposure of the color original D on one photosensitive drum 14 rotating at a constant speed. The latent images formed on the drum are developed by developing devices 4 to 7 with corresponding complementary color toners each time, and the developed toner images are fed from the paper feeding device 30 to the intermediate roller 48, the registration roller 49 and the like. A color copy is obtained by repeatedly transferring the image onto a transfer sheet P which is conveyed through the transfer drum 15 and held and rotated by the transfer drum 15.

The transfer paper P on which the transfer is completed is peeled off from the transfer drum 15 by the separation claw 25, and is conveyed to the fixing unit 40 by the conveying belt 26, where it is fixed by the fixing heat roller 41 and the pressure roller 42. After the transfer image (toner image) formed on the transfer paper is fixed, the transfer image is discharged onto the discharge tray 27 by the discharge roller pair 43.

Next, the developing device 4 for black color development will be described in detail with reference to FIGS.

The developing device 4 for black comprises a developer tank 51 and a toner tank (toner hopper) 52 both serving as a powder storage section. The developer tank 51 is formed by a carrier and toner, and includes a photosensitive member. A powdery developer De used to visualize the latent image on the drum 14 (FIG. 2) is stored.

As shown in FIG. 3, the toner tank 52 is a cylindrical container that extends long in the direction indicated by an arrow A perpendicular to the transfer paper transport direction, and stores therein the toner Tn when used. The cylindrical toner cartridge 53 is attached.

As shown in FIG. 3, the toner cartridge 53 has an agitator 54 inside, and the agitator 54 is provided at a center of the toner cartridge 53 with a rotating shaft 55 provided along the axial direction.
A plurality of toner delivery fins 56 are fixedly arranged at predetermined intervals in the axial direction, and the rotation of the rotation shaft 55 causes the toner delivery fins 56 to rotate. The toner Tn in the cartridge 53 is sent to the toner supply roller 57.

In this embodiment, a desiccant 63 is added to each toner delivery fin 56 of the agitator 54, as shown in FIG.
(Hatched for clarity of existence) are attached by a predetermined length from the vicinity of the rotation shaft 55 toward the tip of the toner delivery fin 56 by bonding or the like.

As shown in FIG. 1, the toner replenishing roller 57 has a plurality of shallow grooves formed in the outer peripheral portion at substantially equal intervals along the circumferential direction. Replenish inside.

The toner cartridge 53 is formed so as to be detachable and replaceable so that the toner cartridge 53 can be replaced with a new one when all the toner Tn in the toner cartridge 53 has been used up.

In the developer tank 51, a stirring roller 58 for stirring and mixing and charging the developer De in the tank, a developing roller 59 for feeding the developer De onto the photosensitive drum 14, and a fixed amount of the feeding amount And a separator 62 for dropping excess developer De onto the stirring roller 58, and a developer De.
And a TS sensor 60 used for concentration control of
A desiccant 63 (specified by hatching) is attached to the separator 62 by bonding or the like.

As the desiccant 63 attached to the toner delivery fins 56 of the separator 62 and the agitator 54, for example, a material having good hygroscopicity, such as silica gel or rice, is suitable.

As described above, in this embodiment, the desiccant 63 is
The toner cartridge 52 is provided in the toner cartridge 53 of the toner tank 52 by being attached to the toner agitating section in the developer tank 51 and the toner delivery fin 56 by being attached thereto. Surplus developer
The De is absorbed by the desiccant 63 when passing through the separator 62.

Further, when the agitator 54 rotates during toner replenishment, the toner Tn in the toner tank 52 is absorbed by the desiccant 63 attached to the delivery fin 56 over the entire area of the toner cartridge 53.

Therefore, the developer De in the developer tank 51 and the toner Tn in the toner tank 52 are constantly absorbed in moisture even when the outside is under a high humidity environment, and the optimal fluidity is maintained. It is not impossible to control the concentration of the agent or to remarkably reduce the replenishment amount of the toner Tn.

[Effect of the invention]

As described above, according to the present invention, the desiccant is attached to the toner delivery fin that rotates in the toner cartridge. Therefore, the desiccant is used to dry the inside of the toner cartridge substantially uniformly over the entire area. Therefore, stable toner fluidity can be obtained regardless of environmental conditions, and toner replenishment can be stabilized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a developing device of a copying machine as a dry electrophotographic apparatus to which the present invention is applied, FIG. 2 is a schematic diagram showing the same copying machine as a whole, and FIG. 3 is a toner tank and a toner cartridge. FIG. 1 Copier body 4, 5, 6, 7 Developing device 14 Photoconductor drum 19 Cleaning device 51 Developer tank 52 Toner tank 53 Toner cartridge 54 Agitator, 62: Separator 63: Drying agent, De: Developer Tn: Toner

Claims (1)

(57) [Scope of request for utility model registration] A toner cartridge for accommodating a powdery toner used for visualizing a latent image on a photoreceptor, wherein the toner cartridge is supplied to a rotating shaft provided inside the toner cartridge. A dry electrophotographic apparatus in which a fin is fixed and the toner delivery fin is rotated in the toner cartridge by the rotation of the rotation shaft to send out the toner outside the toner cartridge; And a desiccant having a predetermined length from the vicinity of the rotation shaft toward the tip of the toner delivery fin.