JPS5893079A - Developer scattering preventing device for pulverulent developing device - Google Patents

Abstract

PURPOSE:To prevent the leakage and scattering of the toner with a simple constitution, by winding a covering member at the outer circumference of a rotary developing device which contains the developing units of different colors in plural section and covering the developing ports which are not used. CONSTITUTION:For a rotary developing device 14, the inside of a main body case 140 is divided into plural sections. Then the developing units 19-22 containing the yellow, magenta, cyan and black developers are set in those divided sections respectively. The magnet rollers 19a-22a are provided along with the cleaning blades 19b-22b, and the developing ports 14a-14d are formed to the case 140 at each position corresponding to each magnet roller. A covering member 15 is made of a long paper sheet, etc. and wound round a draw-out roller 24. The member 15 is wound to the device 14 so as to cover the ports 14b-14d which are not used by the guide rollers 25-27. Then the tip part of the member 15 is wound round a roller 28.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer scattering prevention device, particularly a powder developer (hereinafter referred to as
The present invention relates to a developer scattering prevention device in a powder developing device using toner (referred to as toner).

A color copying machine separates a document into three colors, red, green, and blue, and develops the light image corresponding to each color separately with cyan, Magier/yellow, and yellow toners, which are complementary colors of each color. Requires multiple containers. In this case, configuring the developing units separately and arranging them in parallel around the electrostatic latent image holder increases the size of the apparatus.

Therefore, a rotary type developing device has been proposed, which has a plurality of built-in developing devices, has a developing port for each of the developing devices on the front side, and is rotatably provided close to the electrostatic latent image holder. Although this rotary developing device is extremely effective in downsizing, there is a problem in that toner leaks and scatters from a developing port that is not used for development.

When the leaked and scattered toner adheres to optical components, it significantly impairs optical characteristics and causes deterioration of image quality, and when it adheres to electrical components, it causes short circuits and malfunctions. Furthermore, if it adheres to the sliding parts of mechanical parts, it will significantly accelerate wear and reduce the durability of the machine. Particularly in the case of color development, if leaked and scattered toner mixes with toner in a developing device of another color, areas that are not developed with the regular toner will appear on the copy, resulting in an unsightly image.

Conventionally, in order to prevent toner from leaking and scattering, such as when the developer is removed, a duct suction port has been installed around the developing device.
It has been proposed to surround the developing device with a sponge elastic material. However, the former requires larger equipment and is more expensive. Also, ``It's very noisy.

The latter is inexpensive and does not take up much space, but it is difficult to achieve a complete seal, and when used for a long period of time, the color mixing of leaked toner and scattered toner cannot be ignored.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner scattering prevention device that can reliably prevent toner leakage and scattering in the rotary developing device with a simple configuration.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a cross-sectional view showing an outline of a color copying machine, in which the present invention is applied to a developing device inside the machine, and Figure 2 is an enlarged view of the developing device. First, in FIG. 1, a document loading glass 2 is provided on the top surface of the apparatus main body 1, and while a document 3) placed on this glass 2 is irradiated with a light source 4, moving mirrors 5 and 6, lenses, and 7. An exposure optical system consisting of fixed mirrors 8 and 9 slit-exposes the original image onto a photoreceptor 10 serving as an electrostatic latent image holder. In this case, the moving speed of the moving mirror 6 is 1/2V relative to the moving speed V of the moving mirror 5. Around the photoreceptor 10, there is a primary charger 11, a secondary charge simultaneous exposure device 12. Full-surface exposure lamp 13, rotary developing device 14
, a covering part @15 that covers the outer peripheral surface of the rotary developing device so as to close the developing ports 14b to 14d other than the developing ports (14a in the illustrated example) used for development; A transfer charger 17 that transfers images onto the paper P on the surface of the photoreceptor, and a cleaning grade 18 that cleans the surface of the photoreceptor are arranged in this order.

The rotary developing device 14 described above is rotatably supported by the device main body l by a shaft 23 in close proximity to the photoreceptor 10.

The rotary type developing device 14 has a main body case 140 divided into a plurality of sections (four in the illustrated example), and each section includes a developing device 19 having a yellow developer, a developing device 20 having a magenta developer, and a cyan developer. A developing device 21 having a developer and a developing device 22 having a black developer are provided. Each developing device is provided with magnet rollers 19a to 22a for performing known magnetic brush development GL, and cleaning blades 19b to 22b for scraping off residual toner from the roller surfaces, and a main body case corresponding to each of the magnet rollers. Developing ports 142 to 14d are formed at the position 140 b
Ru. .

The above-mentioned covering member 15 is made of Fi paper, synthetic resin film, metal thin film, etc. in the form of a long sheet.

It is wound around the feeding roller 24 in advance. and,
The covering member 15 fed out from the feeding roller is subjected to development by guide rollers 25, 26, and 27, and is transferred to the developing port 1.
4b to 14d are wound around the rotary developing device 14, and then the leading end of the covering member is attached to the winding roller 28.

In this case, the winding roller 28 rotates in synchronization with the rotation of the rotary developing device 14, and winds up the covering member 15 at the same speed as the outer peripheral surface speed of the developing device 14.

The drive source for the take-up roller 28 may be the same as the rotation drive source for the developing device 14 or may be separate.

In the above embodiment, the photoreceptor 10 and the transfer body 16 are
have the same diameter and are rotated at the same speed in opposite directions as indicated by the arrows, and the color separation filter 29 provided between the fixed mirrors 8 and 9 is selectively rotated for each slit exposure to perform color separation. An electrostatic latent image of a specific color is formed on the photoreceptor 10. Then, when the electrostatic latent image is formed by a blue filter, it is developed with a yellow developer, when it is formed with a green filter, it is developed with a magenta developer, and when it is formed with a red filter, it is developed with a cyan developer. Developed visible I#! are sequentially superimposed and transferred onto the transfer paper P wound around the transfer body 16. This transfer paper P is the photoreceptor 10
The paper is sent out from the paper feed cassette 31 by the paper feed roller 30 in synchronization with the rotation of the paper, travels between a pair of guide plates 32 and 33, and is wound and supported around the transfer body 16 by a holding mechanism (not shown). After the transfer is completed, the transfer paper P is separated from the transfer body 16 by a separation mechanism (not shown), passes through fixing rollers 34 and 35, is heated and pressurized, and is discharged onto a tray 36.

In the above embodiment, when the covering member 15 is completely wound up by the right winding roller 28, the covering member can be used again by exchanging the positions of the left and right rollers and reversing the front and back sides of the covering member. I can do it. Alternatively, by providing a blade 37 or a brush (not shown) on the bottom surface of the take-up roller 28 and scraping off the toner adhering to the surface of the covering member 15, the covering member can be reused by simply changing the positions of the left and right rollers. . 38 is a container that receives the toner scraped off by the blade 37.

Figure ts3 shows another embodiment of the device of the present invention, in which the covering member 15 is formed into an endless shape and is stretched around a drive roller 39 and deflection guide rollers 40 to 42, and is similar to the above example. Effects can be obtained.

As described above, the present invention divides the interior of the main body case into a plurality of sections, and each section is provided with a developing device for different color toner to reduce the size of the rotary type developing device. Since the covering member is wound around the developing port so as to close the developing port, leakage and scattering of toner can be prevented with a simple structure. In addition, since the upper covering member is transported at the same speed as the circumferential speed of the developing device in synchronization with the rotation of the developing device, even if toner leaks from the developer opening that is not used for development and adheres to the covering member. Even so, the toner does not mix with the toner of other developing devices, and there is no risk of any inconvenience caused by toner mixing.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an outline of a color copying machine, and FIG. 2 is a cross-sectional view of a developing device to which an embodiment of the apparatus of the present invention is applied.
FIG. 3 is a cross-sectional view of a developing device to which another embodiment of the present invention is applied. 14 is a rotary developing device, 142 to 14d are developing ports,
15 is a covering member.

Claims (1)

[Claims] The electrostatic latent image holding member is provided in a powder developing device which includes a plurality of developing units, has a developing port for each of the developing units on its side, and is rotatably arranged in contact with the electrostatic latent image holding member. a covering member that covers the outer peripheral surface of the developing device so as to close developing ports other than the developing port facing the developing device; and a covering member that is applied in synchronization with the rotation of the developing device in the same direction as the rotating direction. A developer scattering prevention device in a powder developing device is provided with a drive mechanism that transports the developer at the same speed as the surface speed of the developing device.