JPS59216169A - Preventing device for developer scatter of electronic copying machine - Google Patents

Abstract

PURPOSE:To prevent effectively a developer from scattering by providing a floating plate which moves up and down according to the flow rate of the developer in an area where the developer is transferred from one roll to the other by utilizing difference in electrostatic force. CONSTITUTION:A trimmer 12 which adjust the length of the napping of a magnetic brush 11 is supported fixedly by a trimmer support 13 at the outer circumference of the sleeve 10 of a magnet roll 2. Further, the support 13 is provided with the thin plate type floating plate 15 covering the area 14 where the developer 3 is passed to a photosensitive body 1 by utilizing the difference in electrostatic force, and the plate moves up and down according to the flow rate of the developer 3. Consequently, when the sleeve 10 rotates at a high speed, the magnetic brush 11 also move at a high speed and the brush 11 almost flies outward by its centrifugal force, but the separation and scatter of the developer are prevented by the plate 15, thus preventing effectively the developer 3 from scattering.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a developer scattering prevention device for an electronic copying machine, and particularly to a developer scattering prevention device useful for preventing developer scattering during high-speed copying. Regarding prevention devices.

[Prior art]

Conventionally, a magnetic brush on a magnetic roll has been widely used as a developing or cleaning means.

For example, in a magnetic brush developing device, a developer consisting of a carrier made of iron powder, which has a certain electric charge, and toner, which is attracted to the surface of this carrier by electrostatic force (Coulomb force), is attracted to a magnetic roll. It is conveyed toward the photoconductor while forming a so-called magnetic blank that stands up, and then rubs against the photoconductor surface to which a predetermined potential is applied, forming an electrostatic latent image area on the photoconductor surface that has a large electrostatic force. Development is performed by moving the toner.In recent electronic copying machines, high-speed copying that can make a large number of copies in a short time has been proposed, and the developing device and cleaning device are also High-speed rotation of the photoreceptor and the red sea bream roll facing it is essential.

However, in this case, the following problems have arisen.

That is, for example, in a developing device, when the photoreceptor and Magi-Troll are rotated at high speed, the magnetic brush formed on the surface of the magnet roll also moves at high speed, and the developer forming the magnetic brush and this developer Some of the toner adhering to the agent carrier is subjected to excessive centrifugal force and scatters, colliding with the inner wall of the housing that protects the developing device from the outside and depositing there, eventually landing on the magnetic roll. This caused problems such as falling and adversely affecting the developing effect, or scattering in the form of smoke and adhering to areas other than the latent image area of the photoreceptor, causing a so-called toner cloud and making it impossible to obtain clear copies. .

[Purpose of the invention]

The present invention aims to eliminate the problems of the prior art described above, and more specifically, by providing a floating plate that moves up and down depending on the flow rate of developer, scattering of developer and toner is prevented. It is an object of the present invention to provide a developer scattering prevention device for an electronic copying machine that can effectively prevent the scattering of developer.

[Structure of the Invention] The developer scattering prevention device for an electronic copying machine according to the present invention supplies developer between a pair of rolls disposed adjacent to each other, and utilizes the difference in electrostatic force between each roll. The developer receiver that transfers the developer from one roll to the other roll is provided with a floating plate in the transfer area, and the floating plate moves the surface of the roll that carries the developer to the transfer area in a predetermined direction. In addition to maintaining the spacing, the receiver is fixed at its proximal end toward the transfer area, and its distal end moves up and down in accordance with the flow rate of the developer.

〔Example〕

The present invention will be described below based on embodiments shown in the accompanying drawings.

FIG. 1 shows a developing device to which a developer scattering prevention device according to an embodiment of the present invention is applied.

This developing device includes a magnet roll (2) installed at a predetermined distance from the photoconductor (1), and an iron plate installed in parallel with the magnet roll (2) and constituting the developer (8). A rotatable paddle (6) that stirs a carrier (4) made of a magnetic material such as powder and toner (5), and a rotatable paddle (6) provided above the paddle (6) along the flow of the developer (8). Cover the collected collection plate (7) and each of the above members, and pour the developer (
It consists of a housing (8) that serves as a cover to prevent the magnetic roll (8) from leaking out of the device.
2) A plurality of magnets (9) are disposed inside, and a sleeve αQ to which a predetermined potential is applied is rotatably provided on the outer periphery of the red sea bream roll (2).

Then, on the circumference of this sleeve α0, the developer (3) stands up in the form of a brush due to the magnetic force of the magnet 9) in the magnet roll (2), forming a so-called magnetic brush 0η.
The magnetic roll (2) is equipped with a trimmer (1) and a trimmer support (13) for fixedly supporting the magnetic brush αυ for adjusting the spikes of the magnetic brush αυ to a certain length. It is being

Also, the developer receiver receives and transfers the toner (5) on the sleeve 00 to the surface of the photoreceptor (1) from this trimmer support α, and the proximal side toward the transfer area α is connected to this trimmer support α.
1, and the tip side is provided with a floating plate that moves up and down according to the flow rate of the developer (8), but this floating plate is not affected by the magnetic force of the magnet roll (2). It is formed into a thin plate shape using a magnetic material, and its weight is equal to that of the magnetic brush α.
The developer (8
) can be prevented from scattering due to centrifugal force.

Therefore, according to this embodiment, in the case of high-speed copying in which the photoreceptor (1), sleeve 00, etc. are rotating at high speed, the magnetic brush αη that has passed through the trimmer and has been adjusted to a constant length is
It moves at high speed while being dragged by the high-speed rotation of the sleeve, and the centrifugal force causes it to fly outward and try to scatter, but a floating plate α→ is provided to protect this magnetic brush 01) from the outside. The floating plate α covers the magnetic brush αη while being supported by the spikes of the magnetic brush αυ, and prevents the developer (3) from separating from the magnetic brush α and trying to scatter.
) and toner (5) from scattering. Furthermore, even if some of the developer (3) and toner (5) adhere to the floating plate αQ, new tips of the developer (3) and toner (5) that adhered to this will one after another reach the inner wall of the floating plate αO. Because it is rubbed against the surface, it will eventually be scraped off. Therefore, the inconvenience that the magnetic brush (11) is prevented from adhering to the magnetic brush (11) for a long time and forming a large lump, which causes the passage to become jammed, is avoided.

Although the embodiment described in "-" is a case where the present invention is applied to a developing device, it is of course possible to apply the present invention to a cleaning device.

〔Effect of the invention〕

The present invention has the above-mentioned configuration, and the developer receiver moves up and down according to the flow rate of the developer in the transfer area, which receives and transfers the developer from one roll to the other roll using the difference in electrostatic force. By providing the floating plate, scattering of the developer is prevented and the developer is reliably moved from one roll to the other, so that the copy paper is not contaminated by the scattered developer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to a developing device. Explanation of symbols (1)...Photoreceptor (2)...Magnet roll (3)...Developer (
8)...Housing scream...Sleeve
α Furnace...Magnetic brush α...Developer receiver is the transfer area

Claims (1)

[Claims] The developer side receiver is a transfer area that supplies developer between a pair of rolls placed adjacent to each other, and uses the difference in electrostatic force between each roll to receive and pass the developer from one roll to the other. The receiver covers the surface of the roll that carries the developer to the transfer area while maintaining a predetermined interval. A developer scattering prevention device for an electronic copying machine, characterized in that it is provided with a floating plate that moves up and down.