JPH0463368A - Image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image forming apparatus, and in particular, in a copying apparatus using electrophotographic technology, an automatic cleaning means for IF electric appliances and a The present invention relates to an image forming apparatus equipped with an air flow means for absorbing and exhausting ozone and hot air.

[Prior Art] Conventionally, an image forming apparatus equipped with a charger cleaning device is arranged around a photoconductor tram, for example, as described in Japanese Patent Application Laid-Open No. 54-28633. The charging device includes a charging wire cleaning member movable along the charging wire and a drive mechanism for moving the cleaning member,
11 automatically by operating the drive mechanism at the appropriate time according to a preset program in the control circuit! : I am having the electric wires cleaned. It has also been proposed to manually send an activation signal to the drive mechanism using a manual switch to perform cleaning operations as needed.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology is equipped with an airflow means to dispose of the ozone generated from the charger and the hot air trapped inside the machine, and the inside of the i-electric appliance and its surroundings are Even if an air suction system is adopted, the cleaning operation of the charging wire and the control of the air flow are not controlled in a corresponding manner. The timing for automatic cleaning of the charging wire is usually pre-programmed to occur during a so-called wait-up period immediately after the power is turned on to the machine body, or after a certain period of operation; in any case, it is performed at a time other than during image forming operation. It is generally done in Therefore, during the automatic cleaning of the 4ft wire, the air flow is stopped or is in a so-called half-speed state.For this reason, even if you automatically clean the charging wire, there may be toner or toner that cannot be wiped off with the cleaning member. Problems include dust, etc. floating in the charger and adhering to the surface of the photoreceptor drum or to the charging wire, damaging the photoreceptor and not being fully effective in cleaning the charging wire. was there.

The present invention aims to solve the above problems. That is, the present invention provides an image forming apparatus in which even if the cleaning member is unable to wipe off toner or dust during automatic cleaning of the electric wire, the toner or dust can be removed by suction on the air flow. The purpose is to provide the following.

[Means for Solving the Problems] In order to achieve the above object, the present invention forms an image corresponding to target image information on the surface of an image carrier using an image forming process mechanism including a self-cleaning charging means. In an image forming apparatus having an air flow means for guiding air near the image processing mechanism to another location, 11: Synchronizing with the automatic cleaning operation of the electronic stage, the automatic cleaning operation is performed at a constant rate including before and after the automatic cleaning operation. It has a control means for controlling the flow rate of the air flow in time.

[Function] According to the present invention, the air flow is operated in synchronization with the automatic cleaning operation of the electric wire, that is, during the automatic cleaning operation or at a certain time before and after the automatic cleaning operation, and the air flow is controlled. By controlling the air flow with a valve, etc., the capacity of the air flow related to the electrical equipment can be increased, or by increasing the capacity of the drive source such as a fan that generates the air flow, the cleaning member can wipe the charging wire automatically. It is possible to perform control so that toner and dust that have not been washed away and are floating in the electric appliance are carried on the airflow and removed by suction.

[Example] FIG. 1 is a sectional view showing a first embodiment of the present invention.

In FIG. 1, 0 is a document to be copied, which is placed on a transparent document table 1 with the image side to be copied facing downwards according to a predetermined placement standard, and a document pressure plate 2 is placed over it. Set by. In response to a copy start signal, an electrophotographic photosensitive drum 5 as an image carrier is rotated clockwise around a shaft 5a at a predetermined circumferential speed (process speed), and the circumferential surface of the photosensitive drum is charged by a charging device 6. Uniformly charged positively or negatively. S again! tI light source 3a, move!
I] A known moving optical system 3 consisting of a first mirror 3b, a moving second mirror 3c, a moving third mirror 3d, an imaging lens 3e, a fixed first mirror 3f, a fixed second mirror 3g, a fixed third mirror 3h, etc. The downward image surface of the document 0 set on the transparent document table 1 is sequentially illuminated and scanned from one side to the other side by image formation, and the document image is exposed to light in the exposure section 4a, charged by the charging device 6. The surface of the drum 5 is sequentially exposed to slit images, and electrostatic latent images corresponding to the original image are sequentially formed on the surface of the photosensitive drum 5. 4 is a light shielding plate interposed between the moving optical system 3 and the image forming mechanism below it. Then, the latent image is developed with toner by the first developing device 7a or the second developing device 7b, which has been selected and designated in advance.

The toner development (unfixed transferable image) is subjected to charge removal by the charging device 8, and then transferred to the manual paper feed section 10a or the first cassette paper feed section 58 between the photosensitive drum 5 and the transfer electric device 9. 10b or the second cassette feeding section 10c, and are sequentially transferred onto the transfer material P which is conveyed diagonally by the pair of registration rollers 11 in synchronization with the rotation of the photosensitive drum 5. The transfer material that has undergone the toner image transfer is transferred to the photosensitive drum 5 by the separation charging device 12.
The toner images are sequentially separated from each other and introduced into a heat roller-type heat fixing device 15 by a conveyance device 14 to undergo heat fixation of the toner image. After the toner image has been transferred, the surface of the photosensitive drum 5 is cleaned by a cleaning device 13 to remove residual toner and the like, and is repeatedly used for image formation.

[Thermal fixing device] When the transfer material exiting from 5 is in the mode where it is output as a single-sided copy, it is switched to the flapper 16 (sheet bus switching device) or the solid line water position and then moved to the first guide 1.
7. The paper is output from the pair of paper discharge rollers 18 to the paper discharge tray 19 outside the machine. In the multiple copy mode, the flapper 16 is switched to the position shown by the dotted chain line, and the transfer material that has been copied on one side from the heat fixing device 15 is guided to the second guide 20 side, and is guided to the intermediate tray 21a and the paper refeed roller 21b. It is introduced into an intermediate stock device 21 consisting of etc. In the double-sided copy mode, the flapper 16 waits in the solid line water position, and when the rear end of the transfer material passes the flapper 16, the flapper 16 is switched to the direction opposite to the double-dashed line water position, and at the same time, the paper ejection roller 18 is reversed and the transfer material is guided to the second guide 20 side,
It is introduced into an intermediate stock device 21 consisting of an intermediate tray 21a, a refeed roller 21b, and the like. Then, from the intermediate stock device 21, the sheet is transferred again to the registration roller 11 and conveyed between the photosensitive drum 5 and the transfer mold device 9, thereby performing multiple or double-sided copying.

The charging devices 6, 8 are installed in the image forming process mechanism section consisting of the photosensitive tram 5 and process equipment disposed around the photosensitive tram 5.
, 9.12 generates f-electronic products such as ozone due to corona discharge due to high voltage application. The charged product is wood-philic, and when it adheres to the photosensitive drum 5, it partially reduces the f-type retention of the surface of the photosensitive drum 5, making it easy to cause image disturbance called so-called image deletion. It also contaminates the charging device and causes uneven discharge.

In addition, the vicinity of the photosensitive drum in the image forming process mechanism tends to have a relatively high temperature atmosphere due to the influence of heat from the heat fixing device 15 and the frictional heat of various sliding parts. It tends to aggregate and coagulate, leading to a decrease in image quality of the formed image.

Therefore, in order to remove hot air trapped inside the apparatus body and charged products such as ozone generated near the photosensitive drum (image forming process mechanism) as a result of the operation of the charging device out of the apparatus body as quickly as possible, exhaust air is removed. A fan 50 is provided. The exhaust fan 50 is installed on the back plate side of the main body of the image forming apparatus at an approximately intermediate portion between the image forming process mechanism section including the photosensitive tram 5 and the heat fixing device 15, and is installed on the back plate side of the main body of the image forming apparatus to exhaust hot air containing charged products near the image forming mechanism and The configuration is such that hot air generated from the heat fixing device 15 is promptly removed to the outside of the rear side of the image forming apparatus. In addition, a filter member is installed and used to adsorb, collect, and decompose charged products in the exhaust gas.

In the copying machine of this embodiment, the three process devices, the photosensitive tram 5, the charging device 6, and the cleaning device 13 of the image forming process mechanism section, are assembled into one set and can be detached and replaced from the copying machine body. It is configured as a process cartridge K (process kit). Reference numeral 30 denotes a process cartridge frame (cartridge exterior body) which is detachably attached to the main body of the copying machine, and the %F electric device 6 and the cleaning device 13 are each detachably attached to and supported by the frame 30. The photosensitive tram 5 is rotatably mounted and supported.

An opening 30a is provided on the top surface of the frame 30, and this opening 30a corresponds to and communicates with the back opening 6a of the charging device 6 within the frame 30.

Reference numeral 31 denotes a rail provided between the front plate 40 and the rear plate 41 of the main body of the copying machine. The process cartridge is configured to be detachable from the copying machine main body along this rail 31.

Then, as shown enlarged in FIG. 2, the rail 31
An opening 31a is provided on the top surface of the cartridge, and this opening 31a corresponds to and communicates with the opening 30a of the cartridge frame 30 and the rear opening 6a of the charging device 6.

Also, 32 seen in the first section is an air duct configured to cover the upper part of the rail 31, and this air duct 3
2 and the rail 31 is connected to the exhaust fan 50 described above.

FIG. 3 is a perspective view of the charging device 6, which is equipped with an automatic cleaning mechanism.

In FIG. 3, 61 is a corona discharge wire as a discharge electrode, and a thin tungsten wire or a thin stainless steel wire is used. A shield member 62 is arranged to surround the corona discharge wire 61. 63 is an insulating support member that supports the corona discharge wire 61 and the shield member 62.

64 is a terminal, which connects the high voltage (AC, DC, or a superimposed voltage of AC and DC) from the power source to the corona discharge wire 6.
1 is provided in the discharger. A guide rail 65 is used to detachably attach the corona discharger to the copying machine body, and has the function of grounding the shield member 62 through the copying machine body. Note that a bias voltage can also be applied to the shield member 62 from the guide rail 65. Reference numeral 66 denotes an attachment/detachment knob, which is used when attaching/detaching the corona discharger to/from the main body of the copying machine. 67 is a cleaning member that slides on the corona discharge wire 61 and the shield member 62 while cleaning the direction in which the corona discharge wire 61 is stretched (arrow A←B in the third section).
direction) so that it can slide. This rubbing of the cleaning member 67 cleans the discharge electrode of the corona discharger.

FIG. 4 is a plan sectional view taken along section line XX in FIG. 1.

In FIG. 4, 40 is a front plate, 41 is a rear plate, 42 is a rear cover, 50 is an exhaust fan, 51 is an ozone filter,
52 is a fan duct.

As described above, the space surrounded by the rail 31 and the air duct 32 is connected to the charging device 6 through the opening 31a.
It is connected to the rear opening 6a of the.

Therefore, when a voltage is applied to the exhaust fan 50, the air in the atmosphere of the charging device 6 follows the path shown by the arrow in the figure, passes through the ozone filter 51, and reaches the rear cover 42.
is discharged from the machine body through the opening. Also air duct 3
2 has an opening 32a in part. A shutter 55 is provided in the opening 32a so that the opening 32a can be opened and closed. The shutter 55 is rotatably supported by a pin 56, and a solenoid 57 and a spring 58 are connected to its end 55a.

No voltage is constantly applied to the solenoid 57,
Due to the force of the spring 58, the shutter 55 is in the position shown by the two-dot chain line, and the opening 32a of the air duct 32 is open. When pressure is applied to the exhaust fan 50C7M in this state, as mentioned above,! The air in the vicinity of the electrical device 6 is exhausted to the outside of the apparatus main body, and the air in the vicinity of the thermal fixing device 15 is also discharged to the outside of the apparatus main body from the opening 32a, as shown by the two-dot chain arrow.

On the other hand, when voltage is applied to the solenoid 57, the shutter 55 is attached as shown by the solid line, and the opening 32a of the air duct 32 is closed. When a voltage is applied to the exhaust fan 50 in this state, the air flow is only from the vicinity of the charging device 6. When the opening 32a is closed, compared to when it is open, the flow velocity of the airflow suctioning from the vicinity of the charging device 6 is increased, and the suction efficiency is also improved.

FIG. 5 is a flowchart for controlling the automatic cleaning operation of the F-type device and the opening/closing operation of the air duct shutter.

First, in step 1, it is determined whether it is time to automatically clean the fτ device 6. Even if the F-type device 6 is automatically cleaned at predetermined intervals by accumulating the operating time of the device main body according to a program preset in the control circuit of the device main body, the number of sheets to be passed for image formation is still low. The same judgment can be made in either case, whether automatic cleaning is performed every predetermined number of sheets by accumulating the number of sheets, or even automatic cleaning is performed at any time using a manual switch.

When it is determined that it is time to clean the V electric device 6, 5
Close the shutter 55 as in step 2. This means that when a predetermined voltage is applied to the solenoid 57, the shutter 5
5 rotates around a pin 56 to close the opening 32a.

During this time, a constant voltage continues to be applied to the exhaust fan 50, so when the shutter 55 is closed, the air flow rate from the vicinity of the charging device 6 gradually increases, and after a predetermined time, it becomes constant. The flow rate reaches and becomes stable. During this time, the timer (2) shown at 5tep3 serves to wait for the automatic cleaning of the charging device 6 to start.

After waiting for a predetermined time after closing the shutter 55, the timer starts automatic cleaning of the charging device 6 as shown in step 4.

Next, as shown in step 5, it is determined whether cleaning of the charging device 6 has been completed. This is determined by turning off the microswitch provided in the charging device 6.

The shutter 55 remains closed until a predetermined period of time elapses after the automatic cleaning of the charging device 6 is completed.
It is. Immediately after the automatic cleaning of the charging device 6 is finished, dust and toner powder scraped off by the cleaning member are floating around the charging device 6, so the high-velocity airflow causes these particles to be contained. This is to completely suck the air around the charging device 6.

After the predetermined time set by the timer I+ has passed, the voltage application to the solenoid 57 is turned off, the shutter 55 is rotated by the force of the spring 58, and the opening 32a of the air duct 32 is opened, as shown at step 7. Ru. As a result, the airflow by the exhaust fan 50 is
The airflow from the vicinity of the heat fixing device 15 is added through the opening 32a, and the airflow from the vicinity of the 1i'%i device 6 is reduced from its initial state, returning to the state before the automatic cleaning of the f-type device 6. do.

FIG. 6 shows a part of the second embodiment of the present invention, that is, it is a plan sectional view corresponding to FIG. 4.

This second embodiment differs in configuration from the case of FIG. 4 in that the shutter 55 and its mechanical parts, such as the bottle 56, solenoid 57, and spring 58, are not provided, and the opening 32a of the air tact 32 remains open. be.

That is, in this second embodiment, the air flow velocity is controlled by controlling the voltage applied to the exhaust fan 50. That is, the exhaust fan 50 is normally driven with a steady voltage applied thereto, or a high pressure is applied only for a predetermined period of time in synchronization with the automatic cleaning operation of the charging device 6, thereby increasing the flow rate of the exhaust air flow. This is how it was done.

FIG. 7 shows the structure of the f-type device 6 in the second embodiment. l]
5 is a flowchart for controlling the cleaning operation and the wind speed of the exhaust fan 50. FIG.

First, in step 1, it is determined whether it is time to automatically clean the charging device 6.

When it is determined that it is time to automatically clean the F-type device 6, the applied voltage of the exhaust fan 50 is set to 'High' as shown in 5tep2.Normally, the applied voltage is set to 'LOW'.
If the state is switched to "High," the airflow speed from the vicinity of the charging device 6 gradually increases, and after a predetermined time, The flow reaches a certain level and becomes stable.

During this time, a timer I shown in step 3 is used to wait for the automatic cleaning of the charging device 6 to start.
It is.

After setting the voltage applied to the exhaust fan 50 to ``H1gh'' and waiting for a predetermined time by timer
4, automatic cleaning of the charging device 6 is started.

Next, as shown in step 5, 11! : Mold device 6
Determine whether cleaning has been completed. This turns on the microswitch provided in the charging device 6.

Determined by OFF.

The voltage applied to the exhaust fan 50 remains "High" until a predetermined time period elapses after the automatic cleaning of the charging device 6 is completed, and this predetermined time period is set by the timer II shown in step 6. This is because immediately after the automatic cleaning of the charging device 6 is finished, the dust and toner powder scraped off by the cleaning member are removed! Since it is floating around the electrical equipment room 6, it contains these fine powders due to the high-velocity aeroflow!
This is to completely suck out the air around the electrical equipment room 6.

It is set by the timer It, and after a predetermined time elapses, 5t
As shown in ep7, the voltage applied to the exhaust fan 50 is “L”.
Returned to ow. As a result, the air flow rate by the exhaust fan 50 decreases, and the charging device 6 returns to the state before automatic cleaning.

[Effects of the Invention] As described above, the present invention provides an air flow means for guiding air near an image forming process mechanism including a self-cleaning charging means to another location! The near-flow flow rate can be controlled in synchronization with the automatic cleaning operation of the mold device, so that the dust and toner particles floating near the image forming process mechanism due to the automatic cleaning of the charging device can be removed by the high flow rate. It can be effectively removed by suction. Therefore, scratches on the photoreceptor caused by dust adhering to the photoreceptor can be prevented, and at the same time, dust will not adhere to the IF charging device again and contaminating it, thereby increasing the effectiveness of automatic cleaning of the charging device. be able to fully demonstrate.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG.
2 is a partially enlarged sectional view of FIG. 1, FIG. 3 is a perspective view of the charging device of FIG. 1, and FIG. 4 is a cut #J! of FIG. 1. FIG. 5 is an explanatory flowchart showing the control of the air flow means in FIG. 4; FIG. 6 is a plan sectional view showing only a part of the second embodiment; This figure is an explanatory diagram showing the control of the air flow means of FIG. 6 in the form of a flowchart. 5... Photosensitive tram, 6... Charging device, 31...
・Rail, 31a...opening, 32...air tact, 32a...opening, 50...tJF%
Fan, 51... Ozone filter, 52... Fan tact, 55... Shutter, 57... Solenoid, 58... Spring, 61... Corona discharge wire, 62... Shield member, 67 ...Cleaning parts. 4 other people

Claims (1)

[Claims] 1. Forming an image corresponding to desired image information on the surface of an image carrier by an image forming process mechanism including an automatic cleaning charging means,
In an image forming apparatus having an air flow means for guiding air near the image forming process mechanism to another location, the flow rate of the air flow is controlled for a certain period of time during the automatic cleaning operation in synchronization with the automatic cleaning operation of the charging means. An image forming apparatus characterized by having a control means for controlling the image forming apparatus. 2. The image forming apparatus according to claim 1, wherein a pre-operation control time is included before the predetermined time during the automatic cleaning operation. 3. The image forming apparatus according to claim 1, wherein a post-operation control time is included after a certain period of time during the automatic cleaning operation.