JPS60104972A - Copying device provided with toner dispersion preventing device - Google Patents

Abstract

PURPOSE:To prevent an electrostatic charging device from dirt due to toner by arranging suction ports of a dust collecting duct of a dust collector between a cleaning device and the charging device. CONSTITUTION:The suction ports 15a, 15b of the dust collecting duct 16 are arranged close to both ends of a brade 9 between the cleaning device 2 and the charging device 3. Floating toner generated near both ends of the brade 9 by the rotation of an electrostatic recording body 1 in the arrow B direction is sucked before sticking to the charging device 3 and the toner is removed by a dust collecting filter 17 in a dust collecting box 16 and discharged to the outside in the arrow F direction. Consequently, the charging device 3 is prevented from dirt due to the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a copying machine equipped with a toner scattering prevention device that prevents a charging device from being contaminated by toner.

Conventional configuration and its problems Indirect recording type copying machines that apply the principles of electrophotography sequentially perform each process of charging, exposure, development, transfer, static elimination, and cleaning on the electrostatic recording medium. By doing so, copying is performed as one process cycle.

In the above process, a blade cleaning method in which a blade made of urethane rubber or the like is pressed against the surface of the electrostatic recording medium is often used as the cleaning means. This blade cleaning method has the great advantage that it occupies a small volume inside the copying machine and does not require a special driving source. It has lower rigidity compared to
Because the pressing force is weaker than that at the center, the ability to scrape off toner is inferior, and the toner may pass between the blade and the electrostatic recording material without being scraped off sufficiently from the electrostatic recording material, or the toner may be removed from both ends of the blade. In some cases, the electrolyte could get around to the charging device.

For this reason, in the past, a sealing material such as a sponge was attached to the housing of the cleaning device near both ends of the blade to prevent the toner from floating or scattering from both ends of the blade, but a corona charging device was used for the charging process. Toner that is floating near the charging device is collected inside the charging device just like minute dust is collected in an electrostatic precipitator.

As a result, the charging device was contaminated and the charging ability was partially reduced. The reduction in charging ability causes uneven image density and blurred images, so the charging device has to be cleaned periodically or in response to a call by a service person.

In particular, in a copying machine using a cleaning device configured to reciprocate the blade in the longitudinal direction, even if a sponge is applied to both ends of the blade, the sponge is compressed and released by the blade, so the blade is compressed and released at both ends of the blade. It was not possible to sufficiently prevent toner from floating and scattering.

FIG. 1 shows the main parts of a conventional copying machine. In FIG. 1, 1 is an electrostatic recording medium, 2 is a cleaning device, 3 is a charging device, 4 is a developing device, 5 is a paper feed roller, 6I''i transfer device, 7 is a peeling device, and 8 is a static eliminating device. The optical image is irradiated onto the electrostatic recording medium 1 from the direction of arrow A. A blade 9 is supported in the cleaning device 2 so as to be pressed against the electrostatic recording medium 1, and a sponge 1o is provided at each end of the blade 90. , a toner guide plate 11 is provided below the blade 9.

When the electrostatic recording body 1 rotates in the direction of arrow B, the electrostatic recording body 1
The toner remaining on the surface of the blade 9 is scraped off by the blade 9 as shown by the arrow C and guided downward by the toner guide plate 11.However, at both ends of the blade 9, a portion of the toner remains on the surface of the blade 9 due to static electricity as shown in +iff. The floating toner 12 passes through the recording medium 1 or wraps around the charging device 3 from both ends of the blade 9 .

The floating toner 12 lands on the outside of the charging device 3 and becomes dirt 13. Note that 14 is a transfer sheet discharged after transferring the image as shown by the arrow.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a copying apparatus that can eliminate the above-mentioned conventional drawbacks and prevent a charging device from becoming dirty due to toner scattering from a cleaning device.

Structure of the Invention The present invention includes an electrostatic recording medium, a cleaning device, a charging device, and a dust collection device having a dust collection duct, and the cleaning device is provided on the upstream side in the moving direction of the electrostatic recording medium. Charging devices are disposed on the downstream side, and the suction port of the dust collection duct is disposed between the cleaning device and the charging device.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Second
The diagram is from Kibatsu! This is a perspective view showing the main parts of one embodiment of Ij, and the same parts as in FIG. 1 showing the conventional example are given the same numbers.

In FIG. 2, reference numeral 15 denotes a dust collecting duct, and suction ports 15a and 15b are provided in a space near both ends of the blade 9 between the cleaning device 2 and the charging device 3. A dust collection box 16 has a dust collection filter 17 placed therein, and is configured to be evacuated from the dust collection box 16 by a dust collection fan 18 as shown by arrow F.

With the above configuration, the suction ports 15a, 1 of the dust collection duct 15
5b, floating toner near both ends of the blade 9 generated by the rotation of the electrostatic recording medium 1 in the direction of arrow B or the charging device 3
The toner is sucked in before it adheres to the dust box 16, the toner is removed by the dust filter 17 in the dust box 16, and the toner is exhausted outside the dust box as shown by arrow F.

In addition, in the above embodiment, the dust collection duct is arranged above the cleaning device, but if the suction port of the dust collection duct is located between the cleaning device and the charging device,
Of course, the dust collection duct itself may be routed from three sides of the developing device, for example.

Effects of the Invention As detailed above, according to the present invention, toner that floats and scatters from the cleaning device (particularly near both ends of the blade in the blade cleaning method) is sucked in through the dust collection duct before it attaches to the charging device. It can be exhausted through a dust collection filter, which has the effect of preventing toner from adhering to the charging device. As a result, it is possible to maintain stable quality images without image density unevenness or blurred images caused by dirt on the charging device, and the advantage is that it saves the trouble of having service personnel go to clean the charging device periodically or by calling in advance. There is.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts of a conventional copying apparatus, and FIG. 2 is a perspective view of a copying apparatus equipped with a toner scattering prevention device according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Electrostatic recording body, 2... Cleaning device, 3... Charging device, 9... Blade, 10... River Subonji, 15... ...Dust collection duct, 16a, 15b...Suction port, 18...
...Dust collection fan. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (2)

[Claims] (1) Equipped with an electrostatic recording medium, a cleaning device, a charging device, and a dust collector having a dust collection duct, with the cleaning device located on the upstream side in the moving direction of the electrostatic recording medium, and the cleaning device located on the downstream side in the moving direction of the electrostatic recording medium. A copying machine with a toner scattering prevention device, characterized in that charging devices are respectively disposed, and an inlet of a dust collection duct of the dust collector is disposed at a position between the cleaning device and the charging device. (2) The cleaning device presses the blade against the surface of the electrostatic recording medium, and the cleaning device presses the blade against the surface of the electrostatic recording medium, and the cleaning device
2.) A copying machine with a toner scattering prevention device according to item 1 of the scope of the patent, characterized in that the toner scattering prevention device is provided near both ends of the blade.