JPS60237477A - Recorder having means for preventing scattering of developer - Google Patents

Abstract

PURPOSE:To prevent the decrease in the suction force of a blower for sucking scattering toner owing to the toner sticking thereto and to enable prevention of toner staining in a device for a long period of time by increasing said suction force for certain time after the end of development of a visible image. CONSTITUTION:An ordinary rotating circuit 20 and a high speed rotating circuit 21 are provided to the blower 23 for sucking scattering toner. The circuit 20 is connected thereto in an ordinary copying stage and the blower is run at about the speed at which the developed toner is not sucked. However, a change-over switch 25 is changed over to the high speed circuit 21 by the command from a control part 24 and the blower 23 is run at a high speed for the time set by a timer 22 when the copying stage ends. Therefore the toner sticks to the suction port and duct inside and decreases blower performance if the blower is run at the ordinary speed but such sticking is obviated if the blower is run at the high speed. The toner staining in the device is thus prevented for a long period of time.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a recording device such as an electrophotographic copying machine that performs toner development on an electrostatic charge image to form a visible image. The present invention relates to a recording device having developer scattering prevention means for preventing contamination.

[Conventional Technology] FIG. 1 is a sectional view showing an outline of a generally used transfer type electrostatic recording device. An image of a document 2 placed on the upper part of the apparatus is formed by an optical system 3 having a mirror and a lens onto the circumferential surface of a photosensitive drum 1 which rotates clockwise as an image support. Since the circumferential surface of the photosensitive drum 1 is uniformly charged in advance by the charging electrode 4, an electrostatic latent image corresponding to the original image is formed. This electrostatic latent image is formed on the developing sleeve 6 of the developing device 5.
The toner comes into contact with the developer transported by the latent image area, and the toner adheres to the latent image area to form a visible image (toner image). The transfer paper 7 stored in the paper feeder provided at the bottom of the device is transferred to 1 by the paper feed row 28.
Only one toner image is separated and conveyed and comes into contact with the photoreceptor drum 1, and the toner image formed on the photoreceptor drum 1 is transferred by the transfer electrode 9. The transfer paper 7 to which the toner image has been transferred is transferred to the separation electrode 10
The toner image is separated from the photoreceptor drum 1, transported by a transport device 11 to a fixing device 12, and after the toner image is thermally fused and fixed, is discharged from the device. After the toner image has been transferred, residual toner on the surface of the photosensitive drum 1 is removed by a cleaning device 1.
Cleaned by 3. The above steps are performed for each copy, but the toner is a fine powder of more than 10 microns and easily scatters, and even the slightest movement turns into a mist and floats in the container. Moreover, since the developing sleeve 6 is located inside the developing device 5 and rotates, the toner is very likely to scatter. Although the developing device is sufficiently sealed from the outside, the part in contact with the photoreceptor drum 1 has a gap just enough for the photoreceptor drum 1 to rotate, so toner inevitably leaks from that gap. It will scatter outside. The scattered toner contaminates the conveyance, charging electrode, g-light lamp optical system, etc. inside the apparatus, and prevents formation of a good image. They may also invade mechanical parts such as rotating parts and sliding parts within the apparatus, causing problems in their rotation and sliding, and eventually making the copying operation unsmooth and, in extreme cases, rendering it inoperable.

Conventionally, in order to prevent contamination by the above-mentioned toner, grooves (16 and 16') were generally provided along the top and bottom of the developing device 5.
The vacuum pressure of the blower 15 is used to suck out toner that has leaked or scattered from the gap. This suction force is determined by the structure and rotation speed of the blower 15, but
Contamination by toner can be prevented by increasing the suction force of the blower 15, but since there are ducts (16.16') above and below the developing device, this suction force causes the toner 5a being developed inside the developing device 5 to be further removed. Even the toner image formed on the photoreceptor drum 1 will be attracted.

For this reason, the suction force of the blower 15 must be set to such an extent that it does not suction the toner that is being developed in the developing device. The amount of scattered toner is not constant and constantly changes depending on the type of document, deterioration of the developer, etc. However, if the suction force is set constant for the reasons mentioned above, the amount of scattered toner will be reduced to the set amount of suction. When the amount exceeds the amount, the toner that has not been sucked scatters inside the device and adheres to the vicinity of the suction port of the duct, narrowing the air inlet of the duct and further reducing the amount of suction. As a result, the amount of toner adhesion increases, and the suction of the duct may eventually become sluggish. Furthermore, when the amount of air flowing in decreases, toner accumulates inside the duct pipe, impeding the suction force.

[Object of the Invention] The present invention provides a recording device such as an electrophotographic copying device, in which a blower provided to suck up toner scattered from a developing device section does not suck up toner inside the developing device. Another object of the present invention is to provide a recording device having a developer scattering prevention means that prevents toner from adhering to the suction port of the duct or inside the gas pipe, thereby preventing deterioration in the performance of the blower.

[Structure of the invention] The present invention aims to achieve the above-mentioned object by forming an image on the surface of an image support by using a powder developer by a developing means, and by using a powder developer that scatters in the vicinity of the developing means. In the recording apparatus, the suction means sucks when the developing means forms a visible image on the surface of the image support, and after the development of the visible image is completed, This is achieved by a recording apparatus having a developer scattering prevention means characterized in that the suction force of the suction means is made stronger than during development.

[Example] The suction force of the blower for sucking toner scattered from the developing device section is set to a level that does not suck the toner inside the developing device, but if suction is continued in this state, Toner adheres to the suction port and inside the duct, reducing the suction power. Therefore, in the present invention, the countermeasure is to increase the rotation speed of the blower during a certain period of time, that is, excluding the time to develop the visible image. This is designed to increase the suction power of the blower.

When the suction force of the blower suddenly increases, the toner that has adhered to the suction port of the duct and the toner that has accumulated inside the duct pipe are sucked in without being removed against the suction force, and as a result, the duct is cleaned. Next, when developing a visible image, even if the blower rotation speed is lowered to the set rotation speed, there is no toner adhesion to the suction port and the inside of the duct pipe, so normal cleaning is performed using the preset normal suction force. It happens.

The present invention is to increase the suction force of a cleaning blower for a certain period of time and then return it to the normal suction force after the set time, thereby cleaning the interior of the machine and simultaneously cleaning the suction port of the blower and the inside of the duct.

FIG. 2 shows a theoretical circuit of a blower section according to the present invention. The blower 23, which is connected to the normal rotation circuit 20, is always rotating at a normal rotation speed and with a suction force that does not suck the toner inside the developing device, but when the copying process is completed,
In response to an instruction from the control unit 24 to change the copying cycle, the selector switch 25 is switched to the high-speed rotation circuit 21, and the blower 23 rotates at high speed. The high-speed rotation control section 24 has a timer 21, and the rotation speed is high for a set time of several seconds to several seconds, and after the set time, the control section 24 switches the selector switch 25 to the normal rotation circuit 20 to maintain the normal rotation speed. It has become. The blower is rotated at high speed only for the set time thus set, increasing the suction force to suck out the adhered toner, and constantly cleaning the suction port and the inside of the duct to maintain the normal suction force and cleaning the inside of the device. The timing for cleaning by increasing the number of rotations of the blower and increasing the suction force may be set at a time other than the developing process, such as when fixing is overheated or when copying is completed.

Also, the speed of the blower is changed by changing the resistor, capacitor, etc. of the motor used for the blower, but if you use a dual motor with pole number change, you can easily change the suction force by simply switching the circuit. .

[Effects of the Invention] According to the present invention, by increasing the suction force of the blower for sucking the scattered toner for a certain amount of time, the suction force is prevented from decreasing due to adhered toner, and contamination inside the device is prevented for a long period of time. A recording device having anti-scattering means has been provided.

[Brief explanation of the drawing]

FIG. 1 shows a schematic configuration diagram of a general electrostatic recording device. FIG. 2 shows an embodiment of a theoretical circuit of a blower section according to the present invention. 20... Normal rotation circuit 21... High speed rotation circuit 22... Timer 15.23...
...Blower 24...Control section 25...
Switch agent Patent attorney No 1) Parent-in-law

Claims (2)

[Claims] (1) In a recording device that forms an image on the image support surface using a powder developer by a developing means and has a suction means for suctioning the developer scattered near the developing means, the suction means When a visible image is formed on the surface of the image support by the developing means, suction is performed by the suction means, and after the development of the visible image is completed, the suction force of the suction means is made stronger than during development. A recording device having developer scattering prevention means. (2) A recording apparatus having a developer scattering prevention means according to claim 1, wherein the suction of the suction means that performs suction after the development is operated for a certain period of time by a timer.