JPH01200375A - Copying machine - Google Patents

Abstract

PURPOSE:To efficiently diffuse and delute the residual ozone in an electrifying part before and after copying action comes to the end by providing a means inverting the turn of a discharging fan just before the copying action comes to the end. CONSTITUTION:The moment a copying action starting switch is turned on the motor M of the discharging fan 7b starts normal turn by a signal issued by a motor driving control circuit 10 based on instructions from a control device 9 and continues just before the copying action comes to the end. After that, rotation of the motor M is inverted from a time just before the copying action comes to the end until a certain period passes after the copying action is completed so that turn of the discharging fan 7b is inverted. Air outside the title machine is sucked through a blowing port and blown to an electrifying charger 4a and a transferring charger 4d through an ozone filter 7a or air is blown to them partly directly so as to diffuse ozone stagnating surrounding areas. Thus, the residual ozone in the electrifying part is diffused and deluted so as to efficiently prevent the adverse effect of ozone to a photosensitive body 4, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an exhaust fan that removes ozone generated in the charged parts inside the machine during copying operations and exhausts high-temperature air around the heat generating parts to the outside of the machine. The present invention relates to an electrophotographic copying machine equipped with an electrophotographic copying machine.

[Prior art]

Normally, in an electrophotographic copying machine, relatively high heat is generated during the copying operation from the illumination light source for the original, the fixing device for fixing toner, etc. on the copy paper, and the charger for the photoconductor and the heat on the copy paper. Ozone (03) is generated from transfer chargers, etc., but high heat has a negative effect on photoconductors and cleaners made of organic materials, while ozone deteriorates the characteristics of photoconductors, causing memory formation and image distortion. known to be the cause.

For this reason, in the past, an exhaust fan and an ozone filter were installed inside the machine, and during copying operations, the high-temperature air inside the machine was passed through the ozone filter to remove ozone, and then the air was discharged outside the machine through an air outlet installed in the main body of the machine. A configuration is adopted to discharge the gas.

FIG. 6 is a schematic diagram showing the internal structure of a conventional copying machine.
In the figure, 1 indicates the main body of the copying machine, 2 indicates a document table, and 3 indicates a document cover.

Inside the copying machine main body l, there are a photoreceptor 4, a dual feeder 5 for copy paper P provided extending from a paper feed tray 5a provided on one side of the case l to a paper ejection tray 5d provided on the other side, and a paper ejection tray 5.
A fixing device 6, an ozone filter 17a, and an ozone filter 17a installed near d.
It includes an exhaust device 17 including an exhaust fan 17b.

Around the photoconductor 4, a charger 4a is disposed at the top, and a lens 4b, a developing device 4c, a transfer charger 4d, a cleaner 4e, an eraser lamp 4f, etc. are disposed from there in the rotational direction of the photoconductor 4. An illumination light source 4h that illuminates the document on the document table 2 is disposed on the side of the lens 4b, and a charger 4a applies a constant electric charge to the surface of the photoreceptor 4, and the surface is exposed to the lens. 4b projects and exposes the original image to form an electrostatic latent image on the photoreceptor 4 corresponding to the original image, and the developing device 4c converts the electrostatic latent image on the surface of the photoreceptor 4 into a toner image. The toner image is visualized and transferred to the charged copy paper P at a position facing the transfer charger 4d.

After the transfer of the toner image onto the copy paper P is completed, the photoreceptor 4 is moved to a position facing the cleaner 4e to remove residual toner and dirt from the surface, and then is removed by an eraser lamp 4r to remove residual charge from the surface. This will prepare for the copying process.

On the other hand, the conveyance device 5 of the copying machine P carries a paper feed roller 5b, a timing roller 5c, a guide plate, etc. in this order from a paper feed tray 5a provided on one side of the copying machine main body 1 to a paper discharge tray 5d provided on the other side. A copy paper P is drawn out from a paper feed tray 5a by a paper feed roller 5b, and an electric charge is applied by a transfer charger 4d in accordance with the position of the toner image on the photoreceptor 4 by a timing roller 5c. After passing the toner image between the photoreceptor 4 and the transfer charger 4d and transferring the toner image, the toner image is melted and fixed in the fixing device 6, and then discharged onto the paper discharge tray 5d.

The fixing device 6 includes an upper fixing roller 6a and a lower fixing roller 6b each having a built-in heater.
The upper toner is heated and melted while being pressed against the copy paper P to fix it.

The exhaust device 17 is located above the fixing device 6, and includes an ozone filter 17a and a centrifugal exhaust fan 17b with its suction side facing the ozone filter 17a.
, high-temperature air from the fixing device 6, etc., and the electrostatic charger 4a.
, the ozone generated in the charging section such as the transfer charger 46 is removed by suction through an ozone filter 17a, and then is discharged to the outside of the apparatus.

Note that the exhaust fan 17b is conventionally set to be driven at the same time as the start of the copying operation, and to be driven until a certain period of time has elapsed after the copy paper P has been discharged onto the paper ejection tray 5d, in other words, after the end of the copying operation. .

[Problem to be solved by the invention]

By the way, in such a conventional copying machine, the exhaust fan 17b is arranged with its suction side facing the ozone filter 17a side, so that the negative pressure on the suction side is uniformly distributed behind it through the ozone filter 17a. As a result, it is difficult to intensively suck and discharge ozone from the charger 4a, etc., which is the source of ozone generation, and as a result, the suction and exhaust from the entire interior of the machine is performed, resulting in a poor discharge and removal function. Also, the illumination light source 4
It becomes difficult to exhaust nearby high-temperature air as well.

For this reason, in high-end machines, measures are taken such as installing a dedicated exhaust fan for discharging ozone near the charger 4a.

However, in small copying machines and the like, it is difficult to secure space for a separate exhaust fan, and the exhaust of high temperature air 2 ozone tends to be insufficient.

In order to solve this problem, it is conceivable to continue driving the exhaust fan for a predetermined period of time even after the copying operation is completed, but
8I should be driven for a relatively long time to discharge sufficient ozone! It is not economical because it consumes a lot of electricity,
Further, there is also a drawback that if the main switch is turned off immediately after the copying operation is completed, sufficient exhaust gas cannot be carried out.

The present invention has been devised in view of the above circumstances, and its object is to provide electrophotographic copying with an exhaust fan capable of efficiently diffusing and diluting the ozone remaining in the charging section before and after the end of the copying operation. We are here to provide you with a machine.

[Means to solve the problem]

In the copying machine according to the present invention, immediately before the end of the copying operation,
Means for reversing the exhaust fan is provided.

[Effect]

In the present invention, this allows air to flow intensively to areas where ozone tends to stagnate, thereby diffusing and diluting the ozone.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof.

FIG. 1 is a schematic longitudinal cross-sectional view of a copying machine equipped with an exhaust fan according to the present invention, and FIG. 2 is a schematic vertical cross-sectional view of the copying machine showing a state immediately before the end of copying operation. Copy machine body, 2
3 indicates a document table, and 3 indicates a document cover.

Inside the copying machine main body 1, there is a photoreceptor 4, a paper feed tray 58 arranged on one side of the copying machine main body 1, and a paper output tray 5d arranged on the other side.
It is equipped with a conveying device 5 for the copy paper P provided across the machine, a fixing device 6 for fixing the toner image transferred to the copy paper P onto the copy paper P, and an exhaust device 7 for discharging and removing high-temperature air and ozone inside the machine. .

A charger 4a is disposed above the photoconductor 4, and a lens 4b, a developing device 4c, a transfer charger 4d, a cleaner 4e, an eraser lamp 4f, etc. are connected to the photoconductor 4 in the rotating direction of the photoconductor 4. They are arranged around the lens 4b in this order, and an illumination light source 4h for illuminating the original on the original platen 2 is arranged on the side of the lens 4b.

The charger 4a applies a constant electric charge to the surface of the photoreceptor 4, and the 1/lens 4b projects the original image onto the surface of the photoreceptor 4 to form an electrostatic latent image corresponding to the original image, Further, the developing device 4c visualizes the electrostatic latent image on the surface of the photoconductor 4 into a toner image, and the transfer charger 4d applies electric charge to the copy paper P from the back side of the copy paper P, converting the toner image on the photoconductor 4 into a toner image. It is designed to be transferred onto the top.

The cleaner 4e removes residual toner from the surface of the photoreceptor 4, and the eraser lamp 4f removes residual charge from the surface of the photoreceptor 4 in preparation for the next copying process.

The conveyance device 5 for the copy paper P includes a paper feed tray 5a and a paper feed roller 5.
b. It is composed of a timing roller 5C, a discharge roller 5d, and a plurality of guide members that are located between these and guide the copy paper P.
Copy paper P is pulled out from the holder and passed between the photoreceptor 4 and the transfer charger 4d using the timing roller 5C at the 4.2 position of the toner image on the photoreceptor 4. After the toner image is transferred thereto, the copy paper P is transferred to the fixing device. At step 6, the toner image is fixed and the paper is discharged onto the paper discharge tray 5d. A paper feed sensor 11 is provided between the paper feed roller 5b and the timing roller 5c, and a paper discharge sensor 12 is provided between the fixing device W6 and the paper discharge tray 5d. The position of copy paper P is detected by these sensors 11, 12.

The fixing device 6 includes an upper fixing roller 6a and a lower fixing roller 6b each having a built-in heater, and is designed to melt the toner image on the copy paper P and press it against the copy paper P to fix it. .

The exhaust device 7 is located above the guide member constituting the conveyance device 5 between the photoreceptor 4 and the fixing device 6, and has an ozone filter 7a disposed close to the illumination light source 4h, the charger 4a, and the eraser lamp 4f. In addition, an axial exhaust fan 7b is installed between the ozone filter 7a and the exhaust outlet 1a of the copying machine main body 1, with the exhaust fan 7b facing toward the ozone filter 7a.

FIG. 3 is a block diagram showing the drive control of the exhaust fan 7b, where 8 is a copying operation start switch, and 9 is a block diagram showing the drive control of the exhaust fan 7b.
10 indicates a motor drive control circuit. The motor M of the exhaust fan 7b starts forward rotation at the same time as the copying operation start switch is turned on in response to a signal issued from the motor drive control circuit 10 based on a command from the control device 9, and continues until just before the copying operation ends. After doing 1. The rotation is reversed from immediately before the end of the copying operation until a certain period of time has elapsed after the end of the copying operation.

When the motor M is rotated in the normal direction and the exhaust fan 7b is rotated in the normal direction, air inside the machine is sucked through the ozone filter 7a and discharged to the outside through the air outlet 1a, while the motor M is rotated in the reverse direction.
When the exhaust fan 7b is reversed, air from outside the machine is sucked through the outlet 1a, passed through the ozone filter 7a, and then
・The part is directly connected to the charging charger 4a and the transfer charger 4d.
, spray toward other heat generation sources, charger 4
a, the ozone stagnant around the transfer charger 4d, etc. is diffused, and the heat source is cooled.

Next, the forward and reverse drive control details and drive timing of the exhaust fan will be explained based on the flowchart shown in FIG. 4 and the timing chart shown in FIG. 5.

First, turn on the copy operation start switch 8 (step ■
), the main motor is driven and copying starts;
At the same time, a timer whose time limit is set to the time when the copy paper is detected by the paper ejection sensor immediately before the paper ejection tray is turned on (step ■), and at the same time, the motor M is rotated in the forward direction and the exhaust fan is rotated in the forward direction (step ■). High-temperature air containing ozone inside the aircraft is exhausted to the outside through an ozone filter. It is determined whether or not the timer has reached the time limit (Step 2), and after a certain period of time has elapsed after the copy paper is detected by the paper ejection sensor, the motor M is reversed to start reversing the exhaust fan 7b. (Step ■■), turns on another timer (Step ■), determines whether a predetermined time has elapsed (Step ■), stops the exhaust fan from reversing when the predetermined time elapses (Step ■), exhaust fan ■ End the drive control of 7b.

In the above embodiment, the exhaust fan 7b is rotated in the reverse direction after a certain period of time has elapsed after the copy paper P is emitted by the paper ejection sensor installed immediately before the paper ejection tray 5d, and a paper ejection detection signal is emitted. , it is not limited to this in any way,
Before the main motor stops, the illumination light source 4h, the fixing device 6, etc. are cooled, and the electrostatic charger 4as transfer charger 4
Any time may be used as long as the ozone generated from d can be properly discharged.

〔effect〕

As described above, in the copying machine according to the present invention, the ozone remaining in the charged section is diffused and diluted without continuously driving the exhaust fan for a long time, thereby effectively preventing the adverse effects of ozone on the photoconductor, etc. The present invention has excellent effects, such as making it possible to do the following.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the internal structure of a copying machine according to the present invention;
Figure 2 is a schematic diagram showing the exhaust fan in a reversed state, Figure 3 is a block diagram showing the exhaust fan drive control system,
FIG. 4 is a flowchart showing the drive control process of the exhaust fan, FIG. 5 is a timing chart, and FIG. 6 is a schematic diagram showing the internal structure of a conventional copying machine. 1... Copying machine body 2... Original table 3... Cover 4... Photoconductor 4a... Charger 4C...
-Developing device 4d...Transfer charger 4h...Illumination light source 5...Transporting device 6...Fixing device 7...Ejecting device 8...Copying operation start switch 9...Control device 10...・Motor drive control circuit patent Applicant Minolta Camera Co., Ltd. Agent Patent attorney Noboru Kono Mistake 3 Figure 4

Claims (1)

[Claims] 1. In an electrophotographic copying machine equipped with an exhaust fan that exhausts the air around the heat generating part and the charging part inside the machine to the outside during the copying operation, immediately before the end of the copying operation, the air outside the machine is removed from at least the area around the charging part. A copying machine characterized by comprising means for reversing the exhaust fan so as to blow air into the air.