JPH0443895Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> This invention relates to an ozone evacuation device used in copying machines and the like.

<Prior Art and Its Disadvantages> Image blurring may occur in copying machines and the like when exposed to high temperatures and high humidity, which poses a major problem in terms of copy quality. Generally, the cause of this image blur is that ozone released by corona discharge reacts with nitrogen and dust in the air to form nitrogen oxides that adhere to the surface of the photoreceptor, and the charge on that part escapes. It is believed that this is for the purpose of The following methods can be used to reduce image blur.

(a) Lower the total current value of corona discharge.

(b) Efficiently discharge ozone.

(c) Scrape off the photoreceptor surface.

(d) Use a photoreceptor that does not cause image blur.

Of the above, in (a), the lower the total current value, the better the image blurring, but on the other hand, charge unevenness is more likely to occur, and there is a limit to lowering the current value. (c) has the problem of a decrease in charging ability due to a decrease in film thickness, and (d) has the disadvantage that the photoreceptor is limited. Therefore, method (b) is often adopted as a practical measure. Specifically, for example, (e) Drill a hole in the charger case.

(f) Increase the air volume of forced exhaust through ducts and exhaust fans.

(g) Apply ozone absorbent to the charger case.

There are several methods, but until now, none of these methods could efficiently discharge ozone.

<Purpose of the invention> The purpose of this invention is to provide an ozone discharge device that has a simple configuration and can efficiently discharge ozone.

<Structure of the invention> This invention provides an ozone discharge hole in the charger case of the charging charger, and also provides an ozone discharge hole on the side of the charger case in the rotational direction of the photoreceptor drum, so that the tip of the charger case approaches the surface of the photoreceptor drum when the photoreceptor drum rotates. An ozone discharge shutter is provided, which lowers to the position and moves upward when the photoreceptor drum stops, and furthermore, a dark box containing an optical section is provided with a bottom plate portion of the ozone discharge shutter located on the opposite side from the charging charger, and a portion of the bottom plate located on the opposite side of the charging charger, and the exhaust It is characterized by having an ozone discharge hole provided in a position close to the fan.

<Example> FIG. 1 is a schematic configuration diagram using an ozone evacuation device that is an example of this invention. In the figure, 1 is a photosensitive drum. A charging charger 3, a developing device 2, a transfer charger 4, and a cleaning blade 5 for removing residual toner are arranged around this. 6 is a fixing roller, 7 and 8 are Shirotsuko fans,
9 indicates a light source. Further, 15 is a dark box containing an optical section. In this dark box 15 is a charger 3 of an ozone discharge shutter 11 which will be described later.
and the part of the bottom plate located on the opposite side of the fixing roller 6.
Ozone outflow holes 16 and 17 are respectively provided at positions close to the Shirotsuko fan 8 disposed above. The Shirotsuko fan 7 is coaxially connected to the main motor, and the Shirotsuko fan 8 is driven when the power is switched on. The Shirotsuko fan 7 is disposed at the lower part of the bottom plate of the dark box 15 approximately in the center of the main body of the copying machine. Sirotskov fan 8 has exhaust port 1
It is located close to 0. In the figure, there are approximately five types of airflow within the copying machine body.

A: A flow of ozone discharged from the charging charger 3 having an ozone discharge hole formed in the charger case, passing through the Shirotsuko fan 7 along the lower side of the bottom plate of the dark box 15, and further passing through the Shirotsuko fan 8.

B: Flow of ozone that passes through the transfer charger 4 and the Shirotsuko fan 7, further passes through the Shirotsuko fan 8, and is discharged.

C: A flow of wind in which the heat from the light source 9 passes through the ozone outflow hole 17 and is discharged via the Sirotskov fan 8.

D: Air flow in which the heat of the fixing roller 6 is discharged via the Shirotsuko fan 8.

A′: Ozone outflow hole 16 from the charging charger 3
The ozone flow passes through the optical section along the upper side of the bottom plate of the dark box 15, passes through the ozone outflow hole 17 of the dark box 15, and is discharged via the Shirotsuko fan 8.

In this embodiment, a shutter 11 that is moved up and down by a solenoid 12 is provided on the photosensitive drum rotation direction side of the charging charger 3, and the flow of the ozone A and A' is controlled by the up and down movement of this shutter 11.

Figure 2 is an external view of the above-mentioned charging charger 3;
The figure shows the charging charger and the shutter, and FIG. 4 shows the operating state of the shutter.

As shown in FIG. 2, the charger 3 is provided with a plurality of ozone discharge holes 30 on its upper surface. The ozone flow indicated by A flows through this ozone discharge hole 30. The shutter 11 is arranged so as to be able to move up and down on the side of the charger case 31 in the rotational direction of the photoreceptor drum, and its up and down movement is controlled by turning on and off a solenoid 12 via an actuator 13 .
Shutter 1 when solenoid 12 is on
1 is located at the position indicated by the dotted line in FIG. That is, the tip of the shutter 11 is brought close to the surface of the photoreceptor drum 1. When the solenoid 12 is turned off, the shutter 11 is in the position shown by the solid line in the figure. At this time, the tip of the shutter 11 is quite far from the surface of the photosensitive drum 1. In the figure, numeral 32 indicates a charging wire made of tungsten.

With the above configuration, when the photosensitive drum 1 is rotating, the solenoid 12 is set to the on state.
That is, the tip of the shutter 11 is brought close to the surface of the photoreceptor drum 1. As a result, ozone is prevented from flowing along the surface of the photoreceptor drum 1, and as shown in FIG.
flows in the direction of At this time, the amount of ozone discharged flowing in the direction indicated by A becomes extremely large because the convection generated by the rotation of the photoreceptor drum 1 can be efficiently utilized. In other words, ozone is efficiently discharged to the outside of the copying machine main body. On the other hand, when the photosensitive drum 1 stops rotating, the solenoid 12 is turned off and the shutter 11 moves upward. In this state, ozone on the surface of the photoreceptor drum 1 is discharged in directions A and A', so that ozone stagnation on the surface of the photoreceptor drum, particularly in and around the charger case 3, can be eliminated.

FIG. 5 is a diagram comparing the ozone emission effect when the above-mentioned shutter mechanism is used and when it is not used. In the figure, the larger the value, the larger the amount of ozone emissions. As is clear from FIG. 5, when the photosensitive drum 1 rotates, the shutter 11
By lowering the amount of ozone, the amount of ozone emitted can be greatly increased, and the ozone emission effect can be made high.

(f) Effect of the invention As described above, according to this invention, when the photoconductor rotates, ozone is discharged through the ozone discharge hole of the charger case by utilizing the convection generated by the rotation, and When the photoconductor is stopped, the shutter rises and the charger case shutter side is opened, preventing ozone stagnation in this area, and the ozone in and around the charger case is discharged through the ozone discharge hole provided in the dark box. This makes it possible to efficiently discharge ozone and suppress the occurrence of image blurring in situations such as high temperature and high humidity.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a copying machine using an ozone evacuation device according to an embodiment of this invention. Second
The figure is an external view of the charging charger of the copying machine, Figure 3 is a diagram showing part of the charger and shutter, Figure 4 is a diagram showing the vertical movement of the shutter, and Figure 5 is ozone emission when equipped with a shutter. It is a figure explaining an effect. 1...Photosensitive drum, 3...Electrostatic charger,
11...Shutter, 12...Solenoid.

Claims (1)

[Claims for Utility Model Registration] A dark box containing a photoreceptor drum and an optical section above the housing, and an external light source located close to the dark box and near the light source position within the dark box. The apparatus includes an exhaust fan and a charging charger disposed between the photoreceptor drum and the bottom plate of the dark box and charging the photoreceptor drum by corona discharge, wherein an ozone discharge hole is provided in the charger case of the charging charger. In addition, an ozone discharge shutter is provided on the side of the charger case in the rotational direction of the photoreceptor drum, the tip of which descends to a position close to the surface of the photoreceptor drum when the photoreceptor drum is rotating, and moves upward when the photoreceptor drum is stopped. Further, the dark box is provided with holes for ozone outflow in a portion of the bottom plate located on the opposite side of the charging charger of the ozone discharge shutter and in a position close to the exhaust fan. Ozone evacuation device around the body drum.