JPH046949B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device in a recording apparatus,
In particular, the present invention relates to a developing device that prevents toner contained in a dry developer from scattering outside the developing device.

To give an overview of the above recording device, the first
As shown in the figure, an endless belt-shaped recording body 1 serving as a latent image carrier is stretched between a driven roller 2 and a driving roller 3, and around the recording body 1 is a static eliminator 4 that removes unnecessary potential. A cleaning device 5 that removes unnecessary residual toner, a charging device 6 that applies a required potential to the recording medium 1, an exposure device 7 that projects an image, etc. onto the recording medium 1, and a latent image on the recording medium 1 caused by exposure. It is configured to include a developing device 8 that visualizes the image, a transfer device 9 that transfers the developed image of the recording medium 1 onto the transfer paper P, and a fixing device 10 that thermally fixes the image on the transfer paper P in the order of steps.

In this recording apparatus, the developing device 8 develops the latent image on the recording medium 1 using toner contained in a dry developer.

However, toner easily becomes dust and scatters, and it also adheres to the charge wire of the corona discharger of the charging device 6 and transfer device 9, causing an adverse effect on the image. Efforts have also been made to prevent intrusion. Also,
The scattered toner also contaminates the inside of the recording device, causing various troubles.

The present invention prevents toner from contaminating the inside of a recording device by preventing toner from scattering from the dry developer supply port of the developing device, which causes toner to leak out from inside the developing device. This is what I am trying to do.

The present invention will be explained below with reference to embodiments shown in FIGS. 2 to 5.

FIG. 2 shows a first embodiment of the present invention, in which a developing device 11 includes a tank 12 containing a dry developer D containing toner, and is provided within the tank 12, and is connected to a recording device from a supply port 13 of the tank 12. The developing sleeve 14 supplies a dry developer D to the recording medium (latent image carrier) 1 and performs visualization.

According to the present invention, the conductive members 15 and 16 close to the recording medium 1 are electrically insulated by the insulator S and attached to the supply port 13 of the tank. The conductive members 15 and 16 are located upstream and downstream of the effective development area, respectively, and are given a predetermined potential by the power source E to form an electric field curtain for preventing toner scattering.

In this embodiment, when the toner has a charge in advance (for example, in the case of high-low resistance toner regardless of whether it is one component or two components), the potential applied to the conductive members 15 and 16 can be arbitrarily selected. , the toner can be moved both to the conductive members 15 and 16 side and to the recording medium 1 side, and when the toner does not have a charge in advance (low resistance toner, for example, a one-component electrostatic induction toner) ), toner adheres to both the conductive members 15 and 16 side and the recording medium 1 side. In the case of the latter low-resistance toner, by making the surfaces of the conductive members 15 and 16 facing the recording medium 1 uneven,
By forming a protruding end on the surface and simultaneously increasing the surface area, toner adhesion characteristics can be improved, and more toner can be adhered to the conductive members 15 and 16 side.

In this manner, the electric field curtain created by the conductive members 15 and 16 prevents toner from scattering from the supply port 13 of the tank.

FIG. 3 shows a second embodiment of the present invention, in which a discharge current from a corona discharger 17 such as a charging device 6 is used to apply a predetermined potential to conductive members 15 and 16, for example. This can be easily implemented using a varistor, Zener diode, etc.
In this case, an electrode for flowing current from a part of the discharger 17 is used, and the conductive members 15 and 16 are connected to the recording medium 1.
A predetermined potential having the same polarity as the charged polarity is applied.

FIG. 4 shows a third embodiment of the present invention, in which the conductive members 15 and 16 are grounded. This creates an electric field between them. When forming an electric field, conductive members 15, 1
It is also possible to electrically insulate (float) 6. In either case, charges are induced or polarized in the conductive members 15 and 16 by the electric field caused by the latent image charge, and an electric field curtain is formed.

FIG. 5 shows a fourth embodiment of the present invention, in which a conductive member 15 is provided on a corona discharger 17 and extends to the vicinity of the supply port 13 of the tank, and the other conductive member 16 is grounded. An electric field curtain is formed using the discharge current and the latent image charges of No. 17.

Each embodiment has been explained above, but in short,
In the present invention, a conductive member is disposed close to the latent image carrier near the developing device, and a predetermined potential is applied to the conductive member or the latent image carrier is placed in a floating state. An electric field is formed in the recording device, and as a result, it is extremely rare for toner floating from the developing device to escape from within this field, making it possible to prevent contamination inside the recording device. Various troubles can be prevented.

As mentioned above, regardless of whether the developer is a one-component developer or a two-component developer, and even if the toner is pre-charged or not pre-charged, if any of the above fields is used, direction and is attached.

Furthermore, although an electrophotographic recording device is illustrated as an example, any device that develops an electrostatic latent image may be used, and the latent image carrier may be other than a belt-like one, and the developing device is also illustrated. It is not limited to things.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a general electrophotographic recording apparatus, and FIGS. 2 to 5 are cross-sectional explanatory diagrams of developing devices according to first to fourth embodiments of the present invention, respectively. 1... Recording body (latent image carrier), 11... Developing device, 12... Tank, 13... Supply port, 14...
Developing sleeve, 15, 16... Conductive member, 17
...Corona discharger, D...Dry developer, S...Insulator.

Claims (1)

[Claims] 1. Equipped with a tank containing a dry developer, and a developing sleeve that is provided within the tank and supplies the dry developer to the latent image carrier of the recording device from the supply port of the tank to perform visualization. In a developing device of a recording device, a conductive member close to the latent image carrier is electrically insulated and provided at the supply port of the tank to prevent toner contained in the dry developer from scattering from the supply port of the tank. 1. A developing device for a recording apparatus, characterized in that an electric field curtain for suppressing the occurrence of oxidation is formed by the conductive member.