JPH11327394A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image forming device which achieves the miniaturization of a cleaning means, also ensures the recovery of waste toner, and prevents soiling of an image. SOLUTION: The cleaning means 3 is situated at the top of a photoreceptor 1, and has a case 30, a cleaning blade 31, and temporary storage room 32 and recovery room 33 for waste toner. A magnet material 40 is provided outside the border between the temporary storage room 32 and recovery room 33. The magnet material 40 is fixed to a mounting member 42, which is connected to a mounting member 44 by means of a hinge 43, and the mounting member 44 is fixed to a proper part of the image forming device. The magnet material 40 is vibrated by the operation of the image forming device, and the magnetic force in the case changes. When the magnetic force is strong, it attracts waste toner 5' in the temporary storage room, and when the magnetic force is weak, it allows the waste toner to fall into the recovery room 33, thereby the waste toner is recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus provided with a waste toner collecting device.

[0002]

2. Description of the Related Art An electrophotographic image forming apparatus, such as a copying machine, a laser printer, and a facsimile, which forms an electrostatic latent image on a photoreceptor and adsorbs toner onto the electrostatic latent image to form a visible image is known. Have been.

FIG. 6 shows one structure of such an image forming apparatus.
It is a figure showing an example. In FIG. 1, the photoconductor 1 has a cylindrical drum shape and rotates in the direction of the arrow in the figure. Around the photoreceptor 1, a charging unit 2, a cleaning unit 3, a laser optical system 4, a developing device 6 containing a toner 5, a transfer device 7, and the like are arranged. Is provided. In addition, a first sheet feeding means 10 is disposed on the lower side of FIG.
Is housed.

The surface of the photosensitive member 1 is removed by a static eliminator (not shown), and when the photosensitive member 1 rotates and reaches the charging means 2, the surface thereof is charged to a uniform potential. Then, light on which image information of the document is placed is irradiated from the laser optical system 4, and an electrostatic latent image of the document is formed on the photoconductor 1.

[0005] The electrostatic latent image moves by the rotation of the photoreceptor 1 and reaches the developing device 6, where charged toner is supplied, and the toner is attracted to the electrostatic latent image to be visualized. On the other hand, when the paper feed roller 12 rotates, the transfer paper P is fed to the uppermost transfer paper P and transported to the registration roller 8. The registration roller 8 feeds the transfer paper at a timing so that the toner image formed on the photoconductor 1 overlaps a predetermined position of the transfer paper P.

The transfer device 7 applies a reverse potential to the transfer paper to move the toner image on the photosensitive member onto the transfer paper. The transfer paper on which the toner image is obtained from the photoreceptor 1 in this manner is transferred to the fixing device 1
5 and passes through a nip between a fixing roller 16 having a built-in heater and a pressure roller 17, and the toner is melted and fixed on the transfer paper.

Thereafter, the transfer sheet P on which the image has been formed is discharged by a discharge roller pair 18 with the image side down.
Is discharged on top. The fixing device 15 includes a fixing roller 16 having a built-in heater, a pressure roller 17, and a discharge roller pair 1.
8 and the like, and constitutes a fixing unit B, which is replaced periodically (for example, every 80,000 copies).

The photosensitive member 1, the charging means 2, the cleaning means 3, the laser optical system 4, the toner 5, and the developing device 6 constitute a process cartridge A. As shown in FIG. It is detachable from the apparatus and is also replaced periodically (for example, every 10,000 copies).

FIG. 7 is an enlarged view of the process cartridge A of FIG. The process cartridge A includes a photosensitive member 1, a charging unit 2, a cleaning unit 3, and a developing roller 61.
And the like, and a toner tank 62, and an opening 63 is formed between the two. The opening 63 has a pull-out seal that is hermetically sealed when it is new. After the cartridge A is set, the pull-out seal is pulled out, and the toner 5 is supplied to the developing roller 61. The toner tank 62 is provided at its bottom with toner end detecting means 64 for detecting that the toner has run out.

In such an image forming apparatus, after the toner image is transferred to a predetermined recording medium such as transfer paper P,
A small amount of toner 5 remains on the photoconductor 1. If the remaining toner is left unattended, it moves onto transfer paper at the time of the next image formation, soiling the image and causing image defects. Therefore, the toner 5 remaining on the photoconductor 1 is collected.

In order to collect the toner, a cleaning unit 3 is provided in the image forming apparatus. In this case, a cleaning blade 31 made of an elastic material such as rubber or synthetic resin is provided in a case 30, and the cleaning blade 31 scrapes off residual toner on the photoconductor. The case 30 includes a temporary storage chamber 32 formed directly above the cleaning blade 31 and a recovery chamber 33 formed next to the temporary storage chamber 32. The scraped waste toner 5 ′ is first removed from the temporary storage chamber 32.
Among them, the toner accumulates on the cleaning blade 31, and is further conveyed and stored in a collection chamber 33 such as a waste toner tank.

By the way, such an image forming apparatus has been reduced in cost and size, and in order to realize both of them, a cleaning blade 31 is often provided above the photosensitive member 1. . Cleaning blade 3
The waste toner 5 ′ scraped in step 1 first accumulates in the temporary storage chamber 32 above the cleaning blade 31 as described above. However, if the waste toner 5 'is collected as it is, it does not move into the collection chamber 33 and may flow backward, and when collecting the waste toner 5', the operator's hand or the like is easily stained.

For this reason, in the conventional cleaning means 3, a magnet such as a magnet roller 34 is provided just above the cleaning blade 31 in the temporary storage chamber 32, and the toner is attracted by the magnetic force of the magnet. The formed waste toner is sent to the collection chamber 33.

[0014]

However, there is a demand for further miniaturization. On the other hand, if the magnet roller 34 is arranged in the temporary storage chamber 32, the temporary storage chamber 32 becomes large accordingly, which hinders downsizing.

On the other hand, as shown in FIG. 8, when the magnet roller 34 is simply removed, when the cleaning means 3 is on the photosensitive member 1 as described above, the waste toner 5 ′ remaining in the temporary storage chamber 32. Cannot be collected in the collection chamber 32, and stays on the cleaning blade 31 and accumulates.

Due to the miniaturization, the volume of the temporary storage chamber 32 is also small, and the blowing of waste toner is apt to occur. It is easy to occur.

The present invention has been conceived in view of the above facts, and it is an object of the present invention to provide an image forming apparatus which can reduce the size of a cleaning means, can reliably collect waste toner, and can prevent image contamination. I have.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a cleaning means on a photosensitive member, the cleaning means comprising a case, a cleaning blade provided in the case, In an image forming apparatus having a temporary storage chamber for waste toner and a recovery chamber for waste toner formed in the case, a magnet material is provided outside the upper part of the case near a boundary between the temporary storage chamber and the recovery chamber. It is characterized by: In this case, it is desirable that the strength of the magnetic force in the case by the magnet material is variable.

In order to change the magnetic force, the magnet material is locked so as to be moved by the vibration of the image forming apparatus, or the distance between the magnet material and the case is reduced by a rotating cam. It can be configured to be changeable, or the magnet material can be a rotatable magnet roller.

Further, the magnet material may be configured integrally with a unit that is periodically replaced in the image forming apparatus, or the unit that is periodically replaced may be separate from the cleaning unit. Good.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view of an embodiment of an image forming apparatus according to the present invention, and is a view showing a process cartridge portion thereof.
Since most of the configuration is the same as that of the conventional example, the description will be made focusing on the differences.

In the image forming apparatus of the present invention, the magnet member 40 is provided outside the case 30 of the cleaning means 3. The magnet member 40 is a plate-shaped permanent magnet and is fixed to the lower surface of the mounting member 42 by means such as adhesion.
The mounting member 42 is connected to another mounting member 44 by a hinge 43, and the mounting member 44 is fixed to an appropriate place of the image forming apparatus. Therefore, the magnet member 40 can maintain a state of being substantially in close contact with the upper surface of the case 30. However, since the case 30 is made of synthetic resin, it is not attracted by magnetic force.

The cleaning blade 31 scrapes the untransferred toner from the photosensitive member 1, and the scraped waste toner accumulates on the cleaning blade 31. However, under the influence of the magnetic force of the magnet material 40 outside the case,
The toner is sucked in the direction of the arrow. The waste toner stuck inside the case under the influence of the magnetic force hangs down like an icicle, and when a certain amount or more, a portion where the influence of the magnetic force is reduced occurs. And is collected by dropping into the collection chamber 33 formed at the bottom. In addition, when the magnetic force is reduced, even a small vibration during the operation of the image forming apparatus falls. In particular, since the magnet member 40 is supported by the hinge connection, the magnet member 40 itself is easily moved by the vibration, and the magnetic force is easily changed.

FIG. 2 is a perspective view showing a second embodiment of the present invention, showing details of a magnet material 40 portion. The mounting member 42 has a protrusion 42a on one end side, which is mounted on the cam 45. The cam 45 is integrated with a gear 46, and the gear 46 meshes with one of a gear train (not shown) for driving the image forming apparatus. Therefore, when the image forming apparatus is driven, the gear 46 rotates, and the mounting member 42
5, the magnet member 40 comes into contact with or separates from the case 30. The waste toner adsorbed on the ceiling of the case 30 and lowered like an icicle is affected by a magnetic force that becomes stronger or weaker due to the rotation of the cam 45. When the magnetic force becomes stronger, the waste toner is attracted, and when the magnetic force becomes weaker. The lower portion of the drooped toner drops due to its own weight being heavier than the attraction force due to the magnetic force, and is accommodated in the collection chamber 33.

By doing so, even if the volume of the temporary storage chamber 32 of the cleaning means 3 is reduced, the waste toner 5 'can be transported to the recovery chamber 33 at the rear. A large volume can be secured.

FIG. 3 shows a third embodiment of the present invention using a magnet roller 50 as the magnet material 40. The magnet roller 50 is directly connected to a drive gear train of the image forming apparatus main body by a gear similar to the gear 46 in FIG.

FIG. 4 illustrates a case where the magnet roller 50 has four poles. As described above, if the magnet roller 50 has four poles, the lines of magnetic force also appear as shown by the temporary lines in the figure and rotate together with the magnet roller 50, so that the strength of the magnetic field in the case 30 changes, such as generation and disappearance. Thus, waste toner can be transported.

FIG. 5 shows a fourth embodiment of the present invention. The magnet roller 50 is outside the case 30 and toner does not directly adhere thereto. However, dust and the like floating in the image forming apparatus may cause contamination and magnetic force for a long time. Therefore, it is desirable to replace it with a new one at an appropriate cycle. In this case, it is convenient from the viewpoint of maintenance if the replacement can be performed in accordance with the replacement of a unit that is periodically replaced such as the process cartridge A or the fixing unit B. By the way, the replacement cycle of the process cartridge A is about 10,000 sheets as described above, but this cycle is too short and about tens of thousands of sheets are appropriate. On the other hand, the replacement cycle of the fixing unit B is about 8
This is desirable because it is 0000 sheets.

Therefore, in this embodiment, the magnet roller 50 is provided integrally with the fixing unit B. When the fixing unit B is replaced, the magnet roller 50 can be replaced together, and the magnet roller 50 can always be kept clean. Naturally, the magnet roller 40 may be replaced with the magnet material 40 shown in FIG.

[0030]

As described above, according to the present invention, a cleaning means is provided above a photoreceptor, and the cleaning means includes a case, a cleaning blade provided in the case, In the image forming apparatus having the waste toner temporary storage chamber and the waste toner recovery chamber formed in the above, since the magnet material is provided outside the case near the boundary between the temporary storage chamber and the recovery chamber, cleaning is performed. Even if the means is reduced in size, the waste toner collected from the photoreceptor can be collected from the temporary storage chamber to the collection chamber, and the deterioration of the image due to blowing of the waste toner and defective cleaning can be prevented.

The magnet material is locked to the extent that it is moved by the vibration of the image forming apparatus, or the rotating cam is locked to change the distance between the case and the magnet material. If the configuration is made of a possible magnet roller, the strength of the magnetic force in the case by the magnet material changes, and the waste toner sucked when the magnetic force is strong falls into the collection chamber when the magnetic force becomes weak. Waste toner can be reliably collected.

If the magnet material is configured integrally with a unit that is periodically replaced in the image forming apparatus, the magnet material can be replaced periodically, so that the magnet material is always kept clean. Can be.

If the unit to be periodically replaced is separate from the cleaning means, the unit can be replaced at a unit replacement cycle shorter than the replacement cycle of the cleaning means, so that the state is further cleaned.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a process cartridge of an image forming apparatus according to the present invention.

FIGS. 2A and 2B are perspective views showing details of a magnet material and a peripheral portion thereof, and FIG. 2B is a plan view showing a cam and a gear portion in a second embodiment of the present invention.

FIG. 3 is a view showing an example in which a magnet roller is used as a magnet material in a third embodiment of the present invention.

FIG. 4 is a diagram illustrating a distribution of lines of magnetic force when a magnet roller has four poles.

FIG. 5 is a view showing a fourth embodiment of the present invention in which a magnet material is integrally attached to a fixing unit.

FIG. 6 is a cross-sectional view illustrating a configuration of a conventional image forming apparatus.

FIG. 7 is an enlarged view illustrating a configuration of a cleaning unit in FIG. 6;

8 is a diagram showing a state in which a magnet roller has been removed from the cleaning unit of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 3 Cleaning means 30 Case 31 Cleaning blade 32 Temporary storage room 33 Collection room 40 Magnet material 45 Cam 50 Magnet roller A, B Unit which is replaced regularly.

Claims (7)

[Claims] A cleaning unit provided in the case, a cleaning blade provided in the case, a waste toner temporary storage chamber formed in the case, and a waste toner; An image forming apparatus comprising: a recovery chamber; and a magnet material provided outside a case near a boundary between the temporary storage chamber and the recovery chamber. 2. The image forming apparatus according to claim 1, wherein the strength of the magnetic force in the case by the magnet material is variable. 3. The image forming apparatus according to claim 2, wherein said magnet member is locked to a degree such that it is moved by vibration of the image forming apparatus. 4. The image forming apparatus according to claim 2, wherein a distance between the magnet member and the case can be changed by a rotating cam. 5. The image forming apparatus according to claim 2, wherein said magnet member is a rotatable magnet roller. 6. The image forming apparatus according to claim 1, wherein the magnet member is formed integrally with a unit that is periodically replaced in the image forming apparatus. 7. The image forming apparatus according to claim 6, wherein the unit that is periodically replaced is separate from the cleaning unit.