JPH075488Y2 - Exhaust system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an exhaust device of a corona discharge device such as a copying machine or a printer for charging a photoconductor to a predetermined voltage.

(Prior Art) Conventionally, as shown in FIG. 7, a corona discharge device of this type is composed of discharge wires 1, 1, shields 2 surrounding the discharge wires 1, support blocks 3 provided at both ends of the shield 2, and the like. There was something.

It is widely known that this corona discharge device oxidizes the photoconductor 4 by ozone generated at the time of the discharge and causes a decrease in electric resistance, which adversely affects copying and printing.

Therefore, conventionally, an exhaust device including a suction pipe 5 and a suction fan 6 is provided in the corona discharge device so that ozone generated during corona discharge is sucked into the suction pipe 4 together with the air inside the machine. 5 is discharged to the outside of the machine through an exhaust port (not shown) provided on the suction fan 6 side.

(Problems to be solved by the invention) However, as shown in FIG. 8, the exhaust device guides the air inside the machine from the opening 7 provided in the ceiling of the shield 2 into the suction pipe 5 above it. The negative pressure of the suction fan 6 connected to one end of the pipe 5 is used to suck the entire pipe.

Therefore, a sufficient flow velocity of the air sucked into the suction pipe 5 cannot be obtained, and the flow rate of the air is different from that of the suction fan mounting side.
There will be a difference with the other side. As a result, the ozone remaining in the shield 2 without being exhausted lowers the potential at the time of corona discharge, resulting in a decrease in discharge efficiency and uneven charging, resulting in poor image quality for copying and printing in copying machines and printers. There was a problem that it had an adverse effect.

The present invention has been made to solve this problem, in which the amount of air sucked from the shield to the suction pipe is made constant regardless of whether the suction fan is attached to the suction fan side or the opposite side, and the potential of ozone during corona discharge is increased. It is an object of the present invention to provide an exhaust device for a corona discharge device, which can prevent deterioration of the temperature and can always obtain good copies and prints.

(Means and Actions for Solving Problems) A corona discharge device such as a copying machine or a printer that charges a photoconductor to a predetermined voltage is provided with a suction pipe connected to a suction fan. By providing an air suction port for sucking the air in the machine such as a printer from the downstream side of the photoconductor of the corona discharge device, and a means for controlling the flow rate of the air to make a vortex flow, by the vortex flow generated in this suction pipe, Ozone generated during corona discharge is sucked into the suction pipe together with the air inside the machine and discharged to the outside of the machine.

When a swirl of air is generated in the suction pipe, the flow velocity of the air sucked from the corona discharge device into the suction pipe becomes constant from the suction fan mounting side to the opposite side.

If this flow velocity becomes constant, the flow rate of the air sucked into the suction pipe becomes substantially uniform over its entire length, and ozone generated during corona discharge is also sucked into the suction pipe together with this air. As a result, ozone does not remain in the corona discharge device, and stable copies and prints with good image quality can always be obtained.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a perspective view showing an embodiment of an exhaust device according to the present invention.

The corona discharger is composed of discharge wires 1, 1 and a shield 2 surrounding them, and is arranged on one outer circumference of a photoconductor 4 such as a copying machine or a printer via a block (not shown).

The length of this corona discharge device is almost the same as the axial direction of the photoconductor 4, and another shield 8 is provided outside the shield 2 to make it double.

A suction pipe 5 having a suction fan 6 connected to one end thereof is continuously provided on the upper right side of the shields 2 and 8 in the figure.

The suction pipe 5 has substantially the same length as the shields 2 and 8, and a means for generating a vortex is provided inside thereof.

The air suction port 9 of the suction pipe 5 is installed between the shields 2 and 8 on the downstream side in the rotation direction of the photoconductor 4 as shown in FIG. 2, and from the air suction port 9 to the means for generating the vortex flow. The distance between the shield 2 and the shield 8 is set to about 2 to 5 mm over the entire length of the photoconductor 4 in the axial direction, and the flow rate of air passing therethrough is controlled.

Next, the operation will be described.

By rotating the suction fan 6, the air inside the machine such as a copying machine or a printer is applied with a negative pressure to the photoreceptor 4 of the shields 2 and 8.
The air is sucked into the suction pipe 5 from the air suction port 9 installed on the downstream side of the.

The flow rate of the air is throttled by the shields 2 and 8 extending from the air suction port 9 to the vortex flow generating means, while the vortex flow generating means vortexes the air in the suction pipe 5.

When this air is made into a vortex, the flow velocity of the air in the machine that is sucked into the suction pipe 5 becomes substantially constant over the entire axial direction of the photoconductor 4.

When this flow velocity becomes constant, the flow rate of the air sucked from the downstream side of the photoconductor of the corona discharge device becomes substantially uniform over its entire length. Utilizing this, ozone generated during corona discharge is sucked from the shield 2 into the suction pipe 5 and discharged to the outside of the machine from an exhaust port (not shown).

The present invention is constructed and operated as described above.

Incidentally, FIG. 3 shows another embodiment of the present invention.

This embodiment also has a double corona discharge device shield,
An opening 7 is provided on the upstream side of the shields 2 and 8 in the rotation direction of the photoconductor 4, and an air suction port 9 of the suction pipe 5 is detachably connected to the opening 7 so that the suction pipe 5 has an existing suction. The fan 6 is attached.

FIG. 4 also shows another embodiment of the present invention.

This embodiment shows a shield 2 surrounding the discharge wires 1, 1.
And a suction pipe 5 having a suction fan 6 are separately formed, and an opening 7 is provided above the shield 2 on the upstream side in the rotation direction of the photosensitive member 4, and the air of the suction pipe 5 is provided in the opening 7. The suction port 9 is connected by a seal 10 to reduce the cost.

FIG. 5 also shows another embodiment.

This embodiment was devised in order to further reduce the cost than the embodiment shown in FIG. 4, and the shield 2 and the suction pipe 5 provided with the suction fan 6 are integrally molded,
An opening 7 communicating with the air suction port 9 of the suction pipe 5 as shown in FIG. 6 is provided on the upstream side of the shield 2 in the rotation direction of the photoconductor 4.

(Effect of the Invention) As described above, according to the present invention, ozone generated during corona discharge can be removed almost uniformly over the entire area of the shield 2, so that a copying machine or printer using the same can generate ozone during corona discharge. The ozone does not lower the electric resistance of the photoconductor 4 and a good copy or print can always be obtained.

Moreover, since the ozone generated in the Coroller discharge device is sucked into the suction pipe 5 by the vortex flow, the suction fan 6 for generating the vortex flow is sufficient even if the torque thereof is slightly weak. It helps to reduce costs.

Further, since the ozone discharge efficiency from the corona discharge device is good, it is possible to prevent malfunction of the machine due to prevention of oxidation of peripheral equipment of the device.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an exhaust device provided in the corona discharge device of the present invention, FIG. 2 is a side sectional view of the same, FIG. 3, FIG. 4 and FIG. Side sectional view showing an example,
FIG. 6 is a partial front view of an opening provided in the shield, FIG. 7 is a perspective view of an exhaust device provided in a conventional corona discharge device, and FIG. 8 is a side sectional view of the same. 1 ... Discharge wire, 2 ... Shield, 3 ... Support block, 4 ... Photoconductor, 5 ... Suction pipe, 6 ... Suction fan, 7 ... Opening part, 8 ... Shield, 9 ... Air Suction port, 10 …… Seal.

Claims (1)

[Scope of utility model registration request] 1. A copying machine for charging a photoreceptor to a predetermined voltage,
In a corona discharge device such as a printer,
Provide a suction pipe that can connect the suction fan,
The pipe has an air suction port for sucking air in the copying machine, printer, or the like from the downstream side in the rotation direction of the photoconductor,
By providing a means for controlling the flow rate of the air to make it a vortex, the vortex generated in the suction pipe sucks ozone generated during corona discharge into the suction pipe together with the air in the machine and discharges it out of the machine. An exhaust device characterized by: