JPS6049366A - Developing device of copying machine - Google Patents

Abstract

PURPOSE:To prevent scatter of toner in a housing, etc. and to prevent a transfer part from being stained with toner by boring a slit in the bottom part of the housing, providing a toner recovery box thereunder, and recovering low-charge toner in a developing part through the slit. CONSTITUTION:The housing 6 which has the slit 5 in the bottom part of the development part 3 in parallel to the rotating shaft of a photosensitive body 1 and the toner recovery box 7 which communicates with the slit 5 are provided vertically in order. The developer 4 such as toner 2 in the housing 6 is discharged gradually in air to decrease the amount of electrostatic charge and toner 2 sticking to carrier 8 by electrostatic force is decreased in attracting force and made easy to separate from the carriers 8. Even if this low-charge toner 2a separates from the carriers 8 and is floated in the housing 6, it is recovered in the toner recovery box 7 through the slit 5. Even if the toner 2 sticks to PTL16, etc., under the development part 3, excellent transfer is maintained without staining.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention applies a developer electrostatically onto a photoreceptor in order to convert an electrostatic latent image formed on a photoreceptor into a circular image in a copying machine. The present invention relates to a developing device for adsorption.

[Prior art]

Conventionally, as a developing device for a copying machine, a magnet roll with a plurality of magnets is provided facing the photoreceptor, and the developer is attracted onto a sleeve that rotates on the surface of the magnet roll to generate magnetic energy. By forming a brush and rubbing this magnetic brush on the surface of the photoreceptor,
Various types have been proposed in which development is performed by moving the toner in the developer toward the photoreceptor.

However, in this type of developing device, especially during periods of high temperature and high humidity such as summer, the developer in the developing device is affected by the temperature and humidity and discharges, reducing the amount of charge. Along with this, the electrostatic adhesion between the toner and the carrier decreased, making it easy for the toner to separate from the carrier.For this reason, in the housing of the developing device, this developer was deposited on the paddle or magnetic roll. When the toner in the developer is conveyed and flows by the carrier, it is easy to separate from the carrier and generate a toner cloud, which can degrade copy image quality or damage the photoreceptor and howlamp. It leaks to the outside through the gap and adheres to the light source installed below to assist with transfer, that is, the pre-transfer lamp (PTL), the transfer corotron below it, or the transfer part of the peeling corotron, causing transfer errors. The problem was that it was easy.

[Purpose of the invention]

Therefore, it is an object of the present invention to solve the various problems in the conventional developing device described above. The present invention provides a highly reliable developing device that does not generate toner clouds or stain the transfer section with toner.

[Structure of the invention]

That is, the developing device of the copying machine of the present invention is provided opposite to the photoconductor of the copying machine, and applies a predetermined charge to form a visible image corresponding to the electrostatic latent image formed on the photoconductor. The device is equipped with a developing section that electrostatically attracts the toner contained on the photoreceptor, and a housing that prevents the developer from scattering within the developing section. In addition to opening the slit, a toner collection box is provided below the housing, which communicates with the slit. By collecting the low-charge toner in the developing section through the slit, toner scattering within the housing is prevented. This is to prevent the toner staining on the transfer section.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device for a copying machine according to the present invention will be described below based on embodiments shown in the accompanying drawings.

FIG. 1 shows a developing device of a copying machine to which the present invention is applied;
This developing device is provided facing the photoreceptor (1) and has a predetermined charge (a) in order to form a visible image corresponding to the electrostatic latent image C2 on the photoreceptor (1). A developing section (3) that electrostatically adsorbs the toner (2) of 1- on the photoreceptor (1), and a developing section (3) that electrostatically adsorbs the toner (2) on the photoreceptor (1); 3), and a housing (6) in which a slit (5) is opened in parallel to the rotation axis of the photoreceptor (1) at the bottom of the cover 1; 5) and a toner collection box (7) provided in communication with the toner collection box (7).

The developing section (3) is provided with a Madai-troll (8) having a magnet (10) arranged therein, and a toner (8) that is installed in parallel with the Madai-troll (8) and deposits on the bottom of the housing (6). 2) and a paddle (11) for supplying a developer (4) consisting of a carrier (9) toward a magnet roll (8);
A toner hopper (12) supplies new toner (2) with a predetermined charge into the developing section, and the new toner (2) supplied by the toner hopper (12) is transferred to the developer (2) at the bottom of the clamp (6). A blender (13) that refreshes the developer (4) by evenly mixing it with the developer (4).
).

The magnet roll (7) also has a sleeve (1) on its outer periphery that rotates in the opposite direction to the photoreceptor (1).
4) is provided, and the developer (4) supplied by the paddle +11) f2 is magnetically attracted to the sleeve circle, forming a so-called magnetic brush (15).

Further, below the first image section (3), a PTL (pre-transfer ramp 6) is provided as a transfer assisting means parallel to the rotation axis of the photoreceptor (1), and below it In order to transfer the electrostatic latent image (2) on the photoreceptor (1) to the copy paper, a transfer corotron and a peeling corotron (both shown in Figure 2) are installed in parallel with this PTL (161). ) are provided, and these constitute the transfer section.

Therefore, if the copying machine is left in this environment for a long time, especially during high temperature and high humidity times such as summer, the developer (4) such as toner (2) inside the housing (6) will gradually disappear in the air. As the toner (2) is discharged and its charge level decreases, the adhesion force of the toner (2) that has been adsorbed to the carrier (8) decreases due to the electrostatic force (2), making it easier to separate from the carrier (8). Even if the charged toner (2a) is released from the carrier (8) and floats in the housing (6), this floating toner (2a) passes through the slit (5) and is collected in the toner collection box (7) below. will be collected.

The low-charge toner (2a) collected in the toner collection box (7) is collected once a predetermined number of times or every time a predetermined number of copies are made.
) is removed and disposed of.

In addition, the PTLt16 below the developing section (3), the transfer corotron, the peeling corotron, etc. (not shown) (Nitner (2)) will not adhere and stain them, and in other words, as shown in FIG. Even if you keep making a large number of copies, the conventional developing device f1 shown in Figure 2 (bl)
There is no significant decrease in the amount of TL light, and therefore good transfer can be maintained.

〔Effect of the invention〕

Since the developing device of the copying machine according to the present invention has the above-mentioned configuration, the toner that has been left in a high temperature and high humidity environment for a long time and has become discharged and has a low electric charge is collected through the slit at the bottom of the housing. Since the toner is collected in the toner collection box below, it is possible to always obtain stable copy image quality without the risk of toner cloud or staining of the transfer section.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a developing device of a copying machine according to the present invention, and FIG. 2 is a graph showing a comparison between the conventional type and the present invention regarding changes in the amount of PTL light with respect to the number of copies. Explanation of symbols (1)...Photoreceptor (2)...Toner (3)...Development section (5)...Slit (6)...・・・Housing (7)・・・・・・
Toner collection box (8)...Magnetic roll

Claims (1)

[Claims] A developing device that is provided opposite to the photoreceptor of a copying machine and electrostatically attracts toner with a predetermined charge onto the photoreceptor in order to form a visible image corresponding to the electrostatic latent image formed on the photoreceptor. In the apparatus, the housing of the developing device is provided with a slit in the bottom thereof parallel to the rotation axis of the photoreceptor, and a toner collection box is provided below the housing and communicated through the slit, and inside the developing section. A developing device for a copying machine, which collects low-charge toner through the slit.