JPH06138752A - Contact electrifying device - Google Patents

Abstract

PURPOSE:To prevent deterioration of electrifying function by having residue toner on a photosensitive body stuck to an electrifying member with a simple constitution and to always obtain stable electrifying function where impressed voltage is small, ozone generated quantity is extremely low. CONSTITUTION:The device is provided with an electrifying member feeding roller 103 feeding the long length belt shape electrifying member 102, a winding up roller 104 winding up the long length belt shape electrifying member 102 fed from the electrifying member feeding roller 103, a conductive roller 105 having the long length belt shape electrifying member 102 fed from the electrifying member feeding roller 103 abutted to the photosensitive body 106 and a cartridge type main body 101 integrally containing the electrifying member feeding roller 103, the winding up roller 104 and the conductive roller 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact charging device for charging a photoreceptor of an electrophotographic device.

[0002]

2. Description of the Related Art Conventionally, as a charging device for charging a photoconductor of an electrophotographic apparatus, a non-contact type charging device for charging by corona discharge of a corona charger is generally used as shown by corona charging in FIG. It is used for. However,
This device is disadvantageous in that it requires a high voltage for discharging, and many OPC photosensitive drums that have been widely used recently have many negative charging methods, which generate a large amount of ozone, which is not preferable. There are drawbacks.

Therefore, as a solution to this problem, a contact type charging device (hereinafter referred to as a contact charging device) for charging a charging member by directly contacting the charging member has been proposed. Specifically, the roller charging device shown in FIG. 1B, the brush charging device shown in FIG. 1C, the belt charging device shown in FIG. 3D, and the blade charging device shown in FIG. By using such a contact charging device, the applied voltage can be reduced and the amount of ozone generated can be extremely reduced.

[0004]

However, according to the conventional contact charging device, although the applied voltage is small and the amount of ozone generated can be extremely reduced, the charging member comes into contact with the photosensitive member. Therefore, there is a problem that residual toner on the photoconductor adheres to the charging member over time and the charging ability is significantly impaired, and it is impossible to maintain stable charging ability for a long period of time. still,
The electrophotographic apparatus is basically configured to remove the residual toner on the photoconductor by a cleaning device, but this is not always sufficient in the long term, and it is inevitable that the residual toner adheres to the charging member. The current situation.

Although a method has been proposed in which a fur brush is brought into contact with the charging roller to clean the charging roller, it is necessary to newly provide a cleaning means, which complicates the structure of the charging device itself and requires replacement parts. Is increased, and it is necessary to collect waste toner.

The present invention has been made in view of the above, and it is an object of the present invention to prevent the deterioration of the charging ability due to the residual toner on the photoconductor adhering to the charging member with a simple structure.

Further, the present invention has been made in view of the above, and it is an object of the present invention to require a small applied voltage, generate an extremely small amount of ozone, and obtain a stable charging ability at all times. .

[0008]

In order to achieve the above object, the present invention provides a contact charging device for charging a photosensitive member of an electrophotographic apparatus, a charging member supply roller for supplying a long belt-shaped charging member, A winding roller for winding the long belt-shaped charging member fed from the charging member supply roller,
A cartridge type in which a conductive roller for contacting a long belt-shaped charging member sent from a charging member supply roller with a photoconductor, a charging member supply roller, a winding roller, and a conductive roller are integrally housed. The present invention provides a contact charging device including a main body.

The winding roller described above winds up and moves the long belt-shaped charging member during the image forming operation of the photosensitive member, and does not wind up the long belt-like charging member during the non-image forming operation of the photosensitive member. It is desirable to stop at. Further, the cartridge type main body is integrated with the waste toner bottle and / or the toner bottle, and the entire length of the long belt-like charging member is charged when the waste toner bottle is full or / and the toner bottle is empty. It is desirable that the member supply roller is set to be empty.

[0010]

In the contact charging device of the present invention, the long belt-shaped charging member is fed from the charging member supply roller, and the long belt-shaped charging member is brought into contact with the photosensitive member by the conductive roller to charge the photosensitive member. To do. After that, the long belt-shaped charging member is wound by the winding roller. Further, when the long belt-shaped charging member is entirely sent out from the charging member supply roller and wound up by the winding roller, a cartridge type in which the charging member supply roller, the winding roller, and the conductive roller are integrally housed Replace the main body and replace (replenish) the long belt-shaped charging member.

[0011]

[Embodiment] The contact charging device of the present invention will be described below with reference to [Embodiment 1], [Embodiment 2], [Embodiment 3] and [Embodiment 4].
Will be described in detail with reference to the drawings.

[Embodiment 1] FIG. 1 is a schematic diagram of a configuration and an electrophotographic apparatus of a contact charging device of Embodiment 1. The contact charging device includes a long belt-shaped charging member 102 and a long belt-shaped charging member. Charging member supply roller 103 for supplying the member 102
And a winding roller 104 for winding the long belt-shaped charging member 102 sent from the charging member supply roller 103.
A conductive roller 105 for bringing the long belt-shaped charging member 102 sent out from the charging member supply roller 103 into contact with the photoconductor 106, and the charging member supply roller 10
3, a take-up roller, and a cartridge type body 101 for accommodating a conductive roller 105.

The long belt-shaped charging member 102 is wound around the charging member supply roller 103 and contained in the cartridge type body 101 as shown in the drawing.
In order to prevent the toner from entering the contact surface between 6 and the long belt-shaped charging member 102, the photosensitive member 106 is moved in the direction opposite to the rotating direction. The conductive roller 105 is a metal roller whose surface is covered with epichlorohydrin rubber.

Further, in the figure, reference numeral 106 designates a photosensitive member, 10
7 is a laser writing device, 108 is a developing device, 109 is a transfer paper, 110 is a transfer belt, 111 is a fixing device, 112
Indicates a cleaning device.

FIG. 2 shows the structure of the long belt-shaped charging member 102. The long belt-shaped charging member 102 has a thickness of 500
50 μm of a layer 202 in which carbon is dispersed and mixed in Lumiflon resin on a belt-shaped epichlorohydrin rubber 201 of μm
It is applied in a thickness of m. Further, as another material, a mixture of epiclohydrin and a fluororesin may be coated on epichlorohydrin rubber and used.

A long belt-shaped charging member 102 used in Example 1 (a layer 202 in which carbon is dispersed and mixed in Lumiflon resin is applied on epichlorohydrin rubber 201).
Has a characteristic of low environmental dependence (particularly temperature dependence). FIG. 3 shows a graph in which the volume resistivity and the applied voltage were measured while changing the temperature, and FIG. 3 (a) shows an example in which a layer 202 in which carbon was dispersed and mixed in Lumiflon resin was applied on epichlorohydrin rubber 201. 1 shows a long belt-shaped charging member 102, and FIG. 1B shows a long belt-shaped charging member for comparison, in which carbon is dispersed in an amide resin as a base, and a nylon resin is applied on the base. A member is shown. As is clear from the graph of FIG. 3, the long belt-shaped charging member 102 of this embodiment has low environmental dependence and
Since it is stable, extremely stable charging can be performed.

FIG. 4 shows a mechanism for detecting the end time of the long belt-shaped charging member 102. Inside the cartridge type main body 101, a detection bar 401 that moves (in this case, moves up) depending on the winding amount of the long belt-shaped charging member 102 wound up by the winding roller 104, and a detection bar 401 that winds up. A contact type switch 402 for detecting that the amount has reached a predetermined amount is arranged. When the long belt-shaped charging member 102 is wound by a predetermined amount or more and the switch 402 is turned on, the end of the long belt-shaped charging member 102 is notified via an operation unit (not shown). The detection mechanism is not particularly limited, and for example, a photo sensor or the like may be used.

The operation of the contact charging device of the first embodiment having the above structure will be described. When charging the photoconductor 106,
A voltage is applied to the conductive roller 105 to charge the photoconductor 106 through the long belt-shaped charging member 102. The voltage application method at this time may be direct current alone or a method in which alternating current is superimposed on direct current. At this time, the long belt-shaped charging member 102 is moved by the winding roller 104. The rotation direction of the long belt-shaped charging member 102 is changed in order to prevent the residual toner, which cannot be scraped off by the cleaning device 112, from rotating to the next step.
6 is rotating in the direction opposite to the rotating direction of 6.

As described above, the rotation direction of the long belt-shaped charging member 102 is set so that the residual toner does not enter between the long belt-shaped charging member 102 and the photoconductor 106.
Although it is opposite to the rotation direction of the photoconductor 106, the amount of residual toner increases after the image data having a large image area. Therefore, the take-up roller 104 accordingly changes the length of the long belt-shaped charging member 102. It is designed to speed up the winding speed. Further, the take-up roller 104 is the photosensitive member 1
During the non-image forming operation of 06, the long belt-shaped charging member 102 is stopped without winding, the wasteful consumption of the long belt-shaped charging member 102 is avoided, and the life is extended.

By charging by such a method, the portion of the long belt-shaped charging member 102 in contact with the photoconductor 106 (that is, the portion to be charged) is always the portion to which the toner is not attached. Since the toner is supplied from the roller 103, it is possible to prevent the charging ability from being deteriorated due to the residual toner on the photoconductor 106 adhering to the long belt-shaped charging member 102. Further, since contact charging is performed, the applied voltage can be small and the amount of ozone generated is extremely small.

Further, the residual toner which has not been scraped off by the cleaning device 112 adheres to the long belt-shaped charging member 102 and is stored in the winding roller 104 together with the long belt-shaped charging member 102. It is possible to eliminate the influence of toner accumulation and always obtain a stable charging ability.

Further, as shown in FIG. 4, it is possible to easily know the replacement time of the long belt-shaped charging member 102 by the detection mechanism of the end time of the long belt-shaped charging member 102, and the cartridge type main body. Since the charging member supply roller 103, the winding roller, and the conductive roller 105 are integrally housed in 101, the contact charging device can be easily replaced by replacing the cartridge type main body 101.

In the first embodiment, the cartridge type main body 101 is replaced when the long belt-shaped charging member 102 is wound up by the winding roller 104. When all are wound up by the winding roller 104, the charging member supply roller 103 rotates in the opposite direction to wind up the long belt-shaped charging member 102, and at that time, the long belt-shaped charging member 102 is attached. A reverse bias is applied to the conductive roller 105 so that all the residual toner adheres to the photoconductor 106 side, and the long belt-shaped charging member 102 is cleaned. Can also be reused.

[Second Embodiment] FIG. 5 shows the structure of a contact charging device according to a second embodiment. As shown in the figure, the contact charging device according to the second exemplary embodiment integrates the cartridge type main body 101 and the cleaning device 112 according to the first exemplary embodiment into a cartridge type main body 50.
1 is configured. At this time, the entire length of the long belt-shaped charging member 102 is determined so that the replacement time of the contact charging device coincides with the full time of the waste toner bottle in the cleaning device 112.

In the second embodiment, in addition to the effects of the first embodiment,
Since the waste toner bottle can be replaced at the same time as the replacement of the cartridge type body 501, the serviceability of the maintenance work can be improved.

[Third Embodiment] FIG. 6 shows the structure of a contact charging device according to a third embodiment. As shown in the figure, the contact charging device according to the third exemplary embodiment is configured by integrating the cartridge type main body 101 and the developing device 108 of the first exemplary embodiment into a cartridge type main body 601. At this time, the long belt-shaped charging member 10
The total length of 2 is the time when the contact charging device is replaced and the developing device 108
It is set so that the time when the toner bottle inside becomes empty matches. Here, for example, the total length of the long belt-shaped charging member 102 is 5000 sheets of A4 chart paper,
The toner amount in the developing device 108 may be the same as that of the same number of 6% chart sheets of the same size. The cartridge type main body 601 needs to be provided with an exposure window for writing as shown in FIG.

In the third embodiment, in addition to the effects of the first embodiment,
Since the toner can be supplied simultaneously with the replacement of the cartridge type body 501, the serviceability of the maintenance work can be improved.

[Fourth Embodiment] FIG. 7 shows the structure of a contact charging device according to a fourth embodiment. As shown in the figure, the contact charging device according to the fourth exemplary embodiment is configured by integrating the cartridge type main body 101 of the first exemplary embodiment, the cleaning device 112, and the developing device 108 into a cartridge type main body 701. At this time, the entire length of the long belt-shaped charging member 102 is determined such that the contact charging device is replaced, the waste toner bottle is full in the cleaning device 112, the contact charging device is replaced, and the toner bottle in the developing device 108 is empty. It is stipulated to coincide with the time when.

In the fourth embodiment, in addition to the effects of the first embodiment,
Since the waste toner bottle can be replaced and the toner can be supplied at the same time as the replacement of the cartridge type main body 501, the serviceability of the maintenance work can be improved.

[0030]

As described above, the contact charging device of the present invention winds up the charging member supply roller for supplying the elongated belt-shaped charging member and the elongated belt-shaped charging member fed from the charging member supply roller. A winding roller, a conductive roller for bringing the long belt-shaped charging member sent out from the charging member supply roller into contact with the photoconductor, a charging member supply roller,
Since the winding-up roller and the cartridge type main body for accommodating the conductive roller are integrally housed, the charging ability is prevented from being deteriorated due to the residual toner on the photoconductor adhering to the charging member with a simple structure. be able to. Further, the applied voltage can be small, the amount of ozone generated is extremely small, and a stable charging ability can always be obtained.

Further, the cartridge type main body described above is integrated with the waste toner bottle and / or the toner bottle, and the entire length of the long belt-like charging member is charged at the time when the waste toner bottle is full or / and when the toner bottle is empty. By determining that the member supply roller is empty, the serviceability of the maintenance work of the electrophotographic apparatus can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a contact charging device of Example 1 and a schematic diagram of an electrophotographic apparatus.

FIG. 2 is an explanatory diagram showing a configuration of a long belt-shaped charging member.

FIG. 3 is an explanatory diagram showing that the long belt-shaped charging member has low environmental dependence.

FIG. 4 is an explanatory diagram showing a detection mechanism of the end time of the long belt-shaped charging member.

FIG. 5 is an explanatory diagram showing a configuration of a contact charging device according to a second exemplary embodiment.

FIG. 6 is an explanatory diagram showing a configuration of a contact charging device according to a third exemplary embodiment.

FIG. 7 is an explanatory diagram showing a configuration of a contact charging device according to a fourth exemplary embodiment.

FIG. 8 is an explanatory diagram showing a conventional charging device.

[Explanation of symbols]

 101 Cartridge type main body 102 Long belt type charging member 103 Charging member supply roller 104 Winding roller 105 Conductive roller 501 601 701 Cartridge type main body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Ueyama 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Takaya Muraishi 1-3-6 Nakamagome, Ota-ku, Tokyo Shares Within Ricoh Company (72) Inventor Masako Chiba 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company, Ltd.

Claims (3)

[Claims] 1. A contact charging device for charging a photosensitive member of an electrophotographic apparatus, comprising: a charging member supply roller for supplying a long belt-shaped charging member; and a long belt-shaped charging member fed from the charging member supply roller. A winding roller for winding up, a conductive roller for bringing the long belt-shaped charging member sent out from the charging member supply roller into contact with the photoconductor,
A contact charging device, comprising: a charging member supply roller, a winding roller, and a cartridge type body that integrally houses a conductive roller. 2. The winding roller winds up and moves the long belt-shaped charging member during the image forming operation of the photosensitive member, and winds up the long belt-like charging member during the non-image forming operation of the photosensitive member. The contact charging device according to claim 1, which is stopped without being charged. 3. The cartridge type main body is integrated with a waste toner bottle and / or a toner bottle, and the entire length of the long belt-shaped charging member is the time when the waste toner bottle is full or / and the toner bottle is empty. 2. The contact charging device according to claim 1, wherein the charging member supply roller is set to be empty at a time when.