CN100510999C - Electrification device and image forming apparatus - Google Patents

Abstract

A needle electrode and a cleaning member are provided. A plurality of needles are arrayed upon the needle electrode in a straight line, and protrude towards a surface of a photoreceptor. The cleaning member is disposed movably along the array direction of the plurality of needles between the surface of the photoreceptor and the needle electrode. When the cleaning member moves, the tip portion of each of the plurality of needles in the arranged order, after having been embedded from the surface of the cleaning member into its interior, then exits to the exterior of the cleaning member.

Description

Charging device and image forming apparatus

Cross reference

This non-provisional application based on 35 U.S.C. § 119 (a) require respectively on March 10th, 2006 and on June 5th, 2006 in the patented claim No.2006-066285 of Japan's submission and the right of priority of No.2006-156024, the full content of these patented claims is incorporated by reference at this.

Technical field

The present invention relates to a kind of charging device and a kind of image forming apparatus that comprises this charging device, this charging device will be used for carrying out the surface charging of photoreceptor of the image forming apparatus that image forms to uniform potential by electrophotographic printing method.

Background technology

Form in the processing at image, charging process, exposure process, developing process and transfer process are sequentially carried out in the photoreceptor surface by electrophotographic printing method.

In charging process, use charging device that the surface charging of photoreceptor is arrived uniform electromotive force.

A kind of charging device is the non-contact charger that does not contact the photoreceptor surface.This non-contact charger is by from for there being the electrode discharge of high-tension electricity, thus charging photoreceptor surface.

Using diameter from the charging device of tens microns to 150 microns charger line, at interdischarge interval, produce ozone from the charger line owing to the application of high-tension electricity, and the ozone pollution environment.

Owing to this problem, a kind of charging device of optional use pin electrode is arranged, the ozone amount that uses this charging device to produce when applying high-voltage power supply is less.In this pin electrode, many pins are along arranging with the perpendicular direction of the moving direction on photoreceptor surface, and outstanding towards the surface of photoreceptor.In use, produce near the dirt and pin that dust is attracted to pin electrode of part of high-voltage electric field.If ignore this problem, can not carry out suitable discharge from pin electrode.

Therefore, as describing in the open H11-338265 of Japan's special permission, in the charging device of this prior art, a pair of liner component is arranged to face mutually and the pin of pin electrode is clipped between them, so that this liner component can move along the arranged direction of many pins.Move these liner components by arranged direction, impel these liner components to contact the surface of many pins according to priority, thereby eliminate dirt and the dust that adheres to pin along many pins.

Yet the liner component that is arranged at this prior art charging device is made by the material of for example felt etc.Therefore, can not apply sufficient elastic force, and can easily make the end distortion of the pin of pin electrode these liner components.In addition, the fiber of felt may be owing to being cut with contacting of pin, and the loose part of felt can adhere to the surface of pin, thereby make pin electrode dirty.And, because the side of the pin that liner component contact parallels with the arranged direction of pin, therefore can not clean the whole tip portion of pin reliably, owing to applying of high-voltage electric field, this tip portion is the part of the pin of easy adhesion of dust.

The objective of the invention is: a kind of charging device is provided, when using this charging device, by moving the elastomeric element of the end of many pins that wherein are embedded with pin electrode along the orientation of described pin and the tip of crossing pin, can clean the whole tip portion of pin reliably, and the distortion of pin or the adhesion of fiber do not take place; With the image forming apparatus that comprises this charging device is provided.

Summary of the invention

In the present invention, pin electrode and cleaning member are provided.Many pins are arranged on the pin electrode and towards the surface of photoreceptor as the crow flies to be given prominence to.Cleaning member is arranged to and can moves between photoreceptor surface and pin electrode along the orientation of many pins.When cleaning member moves,, after the surface from cleaning member embeds the inside of cleaning member, be withdrawn into the outside of cleaning member by the tip portion of each root of many pins that put in order.

Description of drawings

Fig. 1 is the cut-open view of image forming apparatus, is applied to this image forming apparatus according to the charging device of the embodiment of the invention;

Fig. 2 (A) is the elevational cross-sectional view of the major part of charging device, and Fig. 2 (B) is the side view of this part;

Fig. 3 is the figure that illustrates by the clean operation of clearer;

Fig. 4 is the figure that pin that pin electrode is shown embeds the length of clearer;

Fig. 5 is the side view of charging device; With

Fig. 6 is the side view of charging device according to another embodiment of the present invention.

Embodiment

Describe the preferred embodiments of the present invention in detail below in conjunction with accompanying drawing.Fig. 1 is the cut-open view of image forming apparatus 100, is applied to this image forming apparatus 100 according to the charging device 1 of the embodiment of the invention.Form pattern as for going up the image that forms image at paper (comprise OHP transparent film for example etc. recording medium), this image forming apparatus 100 has duplicating machine pattern, printer mode and facsimile recorder pattern.These patterns are selected by the operator.Can carry out on two surfaces of described paper, all forming the duplex printing of image by this image forming apparatus 100.

Image forming apparatus 100 comprises original paper reading unit 10, paper supply unit 20, image formation unit 30, paper delivery unit 40 and not shown guidance panel part etc.Original paper reading unit 10 is arranged in the top of the main body of image forming apparatus 100, and comprises contact glass 11, original paper pallet 12, scanister 13 or the like.Scanister 13 comprises light source 14, catoptron 15A to 15C, optical lens 16 and CCD (charge-coupled image sensor) 17.Light source 14 is mapped to light on the original paper that is positioned on the original text platform 11, just perhaps be mapped to be transmitted in original paper on the original paper transfer path R from original paper pallet 12 on.Catoptron 15A to 15C, the light that original copy is reflected is directed to optical lens 16.These optical lens 16 feasible reflected light imagings on CCD17 that guided by catoptron 15A to 15C.And, the electric signal that CCD17 output is corresponding with this reflected light.

Paper supply unit 20 is arranged in the bottom of described main body, and comprises paper supply tray 21 and pickup roller 22.Paper supply tray 21 is deposited the paper that is used for supplying to image formation unit 30 during image forms.And pickup roller 22 is along with the paper that leaves in the paper supply tray 21 is supplied with in rotation seriatim.

Image formation unit 30 is arranged in the below of original paper reading unit 10, and comprises retaining paper bowl 51, laser scan unit (hereinafter referred to as LSU) 37, toner cartridge 31 and fixing device 36.Charging device 1, developing apparatus 33, transfer device 34 and cleaner unit 35 along the direction of the arrow among Fig. 1 be arranged in order toner cartridge 31 around, this direction is the sense of rotation of toner cartridge 31.51 paper that infeed from paper supply unit 20 of retaining paper bowl are inducted between toner cartridge 31 and the transfer device 34.In this image formation unit 30, limit paper transfer path S1 and S2.

Paper delivery unit 40 is arranged in the top of paper supply tray 21, and comprises exit roller 41 and paper delivery pallet 42.Exit roller 41 is being discharged on the paper delivery pallet 42 by the paper that is sent to along paper transfer path S1.And paper delivery pallet 42 is deposited the paper that a pile has been discharged from exit roller 41.

Exit roller 41 can rotate forward and backward.When all forming image on two faces at a piece of paper, the paper of having finished image formation on a face is admitted to exit roller 41 by paper transfer path S1.At this moment, exit roller 41 is along the direction rotation that paper is entered paper delivery pallet 42.Before the back edge of paper was passed through exit roller 41, exit roller 41 still was in the state that clamps paper along opposite direction rotation.Paper passes through by opposite direction along paper transfer path S1, and is sent among the paper transfer path S2 and in transfer path S2 and is overturn by pros and cons, accepts the mimeograph of toner image subsequently under the state of toner cartridge 31 at its back side.After all having formed image on two faces of paper, paper enters paper delivery pallet 42 by exit roller 41.

When pressing the start key that is arranged on the guidance panel part, this image forming apparatus 100 infeeds paper transfer path S1 to paper by rotation pickup roller 22.This paper of having supplied with is sent to retaining paper bowl 51.

When the leading edge of this paper had arrived retaining paper bowl 51, retaining paper bowl 51 stopped the rotation.Then, when the leading edge of paper between toner cartridge 31 and transfer device 34 with toner cartridge on during the leading edge coupling of the toner image that forms, the retaining paper bowl begins rotation.

After carrying out Flame Image Process according to the condition of partly importing from guidance panel, the view data that is read by original reading unit 10 is transferred to LSU37 as print data.Based on above-mentioned view data, LSU37 produces electrostatic latent image on the surface of toner cartridge 31, and this toner cartridge 31 is by charging device 1, by by not shown polygon prism and various lens thereon irradiating laser be charged to predetermined potential.After this, the toner that is attached to the surface of the magnetic roller 33A that is set in the developing apparatus 33 is adsorbed to the surface of toner cartridge 31 and is attached to the there according to toner cartridge 31 lip-deep electric potential differences, thereby makes electrostatic latent image as seen by electrostatic latent image being changed into toner image.

Mimeographed on the surface of paper by transfer device 34 at toner cartridge 31 lip-deep these toner images.After this transfer process, toner cartridge 31 lip-deep residue toners are reclaimed by cleaner unit 35.

After finishing transfer process, paper is by through fixing device 36 and through being heated and pressure, and toner image fusing and be attached to the paper surface.After toner image was by such photographic fixing, paper entered paper delivery pallet 42 by exit roller 41.

Fig. 2 (A) and Fig. 2 (B) are respectively main elevation cross-sectional view and the side views that this charging device 1 is shown.This charging device 1 comprises pin electrode 2, support 3, support component 4, clearer 5, actuator shaft 6 and housing 7.This charging device 7 is arranged in the top of toner cartridge 31.

Pin electrode 2 is made by strip shape metal material, and many pin 2A are outstanding downwards with fixing interval on its total length from its lower limb part.Described many pin 2A arrange along the directions X that the length direction with pin electrode 2 parallels.This directions X is corresponding to " orientation " of claim.This charging device 1 is arranged such that the directions X of pin electrode 2 is parallel to the axial direction of toner cartridge 31.The length of pin electrode 2 is greater than the circumferential surface of toner cartridge 31 length at its axial direction.

Support 3 is made by the insulating material of for example resin etc., and it comprises support section 3A and terminal part 3B.Support section 3A supports pin electrode 2.The length of this support section 3A is greater than the scope of arranging described many pin 2A.Support section 3A is at the constant shape of cross section that has on its cross section vertical with directions X shown in the profile line among Fig. 2 (A).Terminal part 3B supports the terminal that does not illustrate in the drawings.These terminals are connected to the high-voltage power supply that does not illustrate in the drawings, and are connected to described pin electrode 2.

The lower surface of support component 4 opens wide, and is installed in the outside of support section 3A from the top.Projection 4A and 4B are formed on the inside surface of support component 4.In vertical direction, support component 4 is clipped in support section 3A between the upper inside surface and protruding 4A, 4B of support component 4, and in the horizontal direction, support component 4 is clipped in support section 3A between the interior side-wall surface of support component 4.Therefore, the moving of support component 4 (comprising its rotation) is by adjusting with perpendicular its inner wall surface of directions X.

Clearer 5, i.e. " cleaning member " in claims supported so that rotatable by the end portion of support component 4.As an example of clearer 5, this clearer 5 can be the flexible member of being made by EPDM (ethylene-propylene-diene rubber) the class elastomeric material of the polishing material of for example aluminium powder that comprises about 10% weight etc. or alkene class elastomeric material etc.The hardness of this polishing material should be set to be lower than the hardness of the raw material (for example can be stainless steel) of pin electrode 2, and for example is higher than the dirt of toner etc. or the hardness of dust.The tip portion of pin 2A from the circumferential surface of clearer 5 to the inside that is embedded in clearer 5.

For the resilient material of making clearer 5, can select suitable material from present known elastomeric material and resin material by experiment, as long as can flexibly being out of shape, this material is difficult for being thrust it and cutting from the pin 2A that it withdraws from.And, for polishing material, this material can use the material of from present known material, suitably choosing, and can incorporate it into resilient material, as long as can be eliminated dust and toner and not apply any surface that damages pin 2A from the surface of pin 2A by present known method.

Actuator shaft 6 is corresponding to " shaft element " in claims, and its rear end is fixed among the bore portion 4C of support component 4.The anterior end that does not illustrate in the drawings of actuator shaft 6 is anterior outstanding from support 3.

Housing 7 be installed on the total length of support 3 support component 4 above.These housing 7 these pin electrodes 2 of protection.

When high-voltage power supply was applied to pin electrode 2 by being installed in terminal on the terminal part 3B, the electric field that applies concentrated on the tip portion of every pin of many pin 2A of pin electrode 2, thereby can easily produce discharge in these parts.Therefore, every pin from many pin 2A discharges to the surface generation of toner cartridge 31.And because this discharge, the surface of toner cartridge 31 is charged to predetermined potential.

At least in arranging the scope of many pin 2A, with the shape of cross section of the perpendicular support section 3A of directions X be constant.Support component 4 is installed in the outside of support section 3A.Support component 4 be arranged to so that limit its with perpendicular its of directions X surface in mobile (comprising its rotation).Support component 4 is by support section 3A guiding, makes it is movably and along the directions X to-and-fro movement at least in the scope of arranging many pin 2A.

Fig. 3 is the figure that illustrates by the clean operation of clearer 5.When support component 4 when directions X moves, clearer 5 also moves with support component 4.At this moment, the every pin of many pin 2A embeds the circumferential surface of clearer 5 according to priority.Owing to the many resistances that pin 2A causes on the circumferential surface that acts on clearer 5, clearer 5 moves along directions X in rotation.When clearer 5 so in rotation the time when directions X moves, the tip portion of pin 2A is withdrawn into the outside from this inside behind the inside of the circumferential surface that embeds clearer 5.

Clearer 5 is arranged between the circumferential surface of pin electrode 2 and toner cartridge 31.The diameter of this clearer 5 is made big as far as possible, as long as it does not contact the circumferential surface of toner cartridge 31.So when directions X moves, at least one tip portion of pin 2A always embeds clearer 5 from the circumferential surface of clearer 5 at clearer 5.Clearer 5 is along directions X moves time rotation, the damage that makes that tip portion by pin 2A causes to the circumferential surface of clearer 5, and least limit is reduced in the distortion of the pin 2A that is caused by the circumferential surface of clearer 5.

The Support Position that is used for the support component 4 of clearer 5 is configured such that the circumferential surface that embeds clearer 5 from the tip portion of the predetermined length of the end of every pin 2A.More specifically, as shown in Figure 4, when the length L 1 of pin 2A was 1.5mm, the length L 2 of their region of discharge was 0.1～0.2mm.Embedding distance L 4 is 0.6～1.0mm.When pin 2A embedded clearer 5, the elastic deformation among the pin 2A occurred in the scope of the length L 3=0.3 of region of discharge L2～0.4mm.

When clearer 5 and support component 4 when directions X moves, after the tip portion of every pin 2A thrust the inside of clearer 5 from its end gradually, then, this tip portion was withdrawn gradually and is exposed to the outside.In this process, the resilient material of clearer 5 is made in the whole tip portion contact of pin 2A, and is polished by the polishing material that this resilient material comprises.Because in clearer 5 rotation, many pin 2A insert clearer 5 according to priority and from clearer 5 withdrawals, therefore, the pin 2A of every pair two adjacency embeds the circumferential surface of clearer 5 with different positions at least.Therefore, cleaned the whole surface of the tip portion of pin 2A in reliable mode.

Fig. 5 is the side view of charging device 1.This charging device 1 side thereon comprises actuator shaft 6.The length of actuator shaft 6 is approximately equal to the total length of support 3.The end of the rear side of actuator shaft 6 is fixed among the bore portion 4C of support component 4.On the fore-end of support 3, form assembled portion 9.This assembled portion 9 has the approximately uniform profile with terminal part 3B.Bearing element 8 is fixed to the rear surface side of assembled portion 9.Bearing element 8 has used the parts identical with support component 4, and is provided with bore portion 4C at an upper portion thereof.Bearing 9A is formed on the upper surface of assembled portion 9.

Actuator shaft 6 passes the bore portion 4C of bearing element 8 and the bearing 9A of assembled portion 9.Handle 6A is assemblied on the end of front side of actuator shaft 6.Under the state in charging device 1 is installed in image forming apparatus 100, end portion supports part 3A, bearing element 8 and assembled portion 9 are positioned at outside the scope of toner cartridge 31 lip-deep image forming area W.In addition, under the state that does not clean, support component 4 is arranged in holding fix, and this wait position is arranged in the zone outside the toner cartridge 31 lip-deep image forming area W.Support component 4, end portion supports part 3A, bearing element 8 and assembled portion 9 do not hinder toner cartridge 31 lip-deep images to form.

When the operator wished to clean pin electrode 2, he caught handle 6A and along the directions X actuator shaft 6 of pulling back.By so doing, support component 4 moves around along directions X, simultaneously by support section 3A guiding, and clearer 5 rotations of supporting by support component 4 simultaneously, many pin 2A of pin electrode 2 embed the surface of clearer 5 according to priority.

When the tip portion of many pin 2A of pin electrode 2 thrusts the inside of clearer 5 and during from the inside withdrawal of clearer 5 according to priority, because the whole zone contact clearer 5 of the tip portion of every pin 2A, and the distortion of pin 2A and the adhesion of fiber do not take place, therefore, can clean the whole surface of the tip portion of pin 2A in reliable mode.

In addition, support actuator shaft 6 at three points: support component 4, bearing element 8 and bearing 9A.Therefore, can carry out the reciprocal operation of actuator shaft 6 to and fro with smooth mode along directions X.

Not necessarily must use clearer 5 as cleaning member; Also acceptablely be, use some support component 4 upper supports so that the rotatable rotary element.

Fig. 6 is the side view of charging device 1 according to another embodiment of the present invention.In the charging device 1 according to this embodiment, replacement is illustrated in the actuator shaft 6 of the charging device 1 of Fig. 2 to 4, screw rod 61 and motor 62 is provided, and forms female thread portion in the bore portion 4C of support component 4.The rotation of motor 62 is passed to this screw rod 61.This motor 62 is the described drive sources of claims, and can forward and reverse rotation.This female thread portion is screwed on the screw rod 61.

Support component 4 is arranged to: the restriction support component 4 with orientation X perpendicular the surface in move with respect to support 3.Support component 4 can not make the orientation X rotation into axis.The rotation of screw rod 61 is converted to the axial direction power along screw rod 61, and this power is passed to support component 4.By supply to from motor 62 screw rod 61 forwards to the rotation of backward directions, can be along the orientation X support component 4 that moves around.And,, can automatically carry out the cleaning of pin electrode 2 by with predetermined timing driving motor 62.

Can arrange compact motor 62 to be assembled to charging device 1, thereby when charging device 1 was installed to image forming apparatus 100, this electric electromechanics was connected to the power supply unit of image forming apparatus 100.Also acceptable is arrange motor 62 to be installed to image forming apparatus 100, thereby when charging device 1 was installed to this image forming apparatus 100, the end of screw rod 61 to be mechanically connected to the turning axle of motor 62 at its rear side.

At last, in the above-mentioned explanation of the embodiment of the invention, all features illustrate in the mode of example, and should not be considered to the present invention is had restricted.Scope of the present invention be can't help any feature of the foregoing description and is limited, but is only limited by the scope of appended claims.In addition, the equivalent of the key element in claims and the variant in the legal and suitable scope of claims also are considered to be included in the scope of the present invention.

Claims (10)

1. charging device comprises:

Pin electrode in this pin electrode, is arranged as the crow flies towards many outstanding pins of photoreceptor surface; With

Cleaning member, this cleaning member is rotating, it is arranged between described photoreceptor surface and the described pin electrode, so that can move rotationally along the orientation of described many pins;

Wherein, during described cleaning member moved rotationally, after the tip portion of each root of described many pins embedded the inside of this cleaning member from the surface of described cleaning member according to priority, this tip portion was withdrawn into the outside of this cleaning member.

2. charging device as claimed in claim 1 also comprises:

Support, it keeps described pin electrode, and, at least in the scope of the orientation of described many pins, this support with the perpendicular shape of cross section of described orientation be constant; With

Support component, it keeps by described support, and be arranged to so as to limit its with the perpendicular direction of described orientation on move, and this support component rotatably supports described cleaning member.

3. charging device as claimed in claim 2, wherein, during the moving of described cleaning member, at least one described inside that embeds described cleaning member of described many pins.

4. charging device as claimed in claim 2, also comprise spindle unit, its first end is fixed to described support component, and its second end is exposed to the fore-end of described support, and this spindle unit is supported on two points of this support, so that removable along this orientation along described orientation.

5. charging device as claimed in claim 3, also comprise spindle unit, its first end is fixed to described support component, and its second end is exposed to the fore-end of described support, and this spindle unit is supported on two points of this support, so that removable along this orientation along described orientation.

6. charging device as claimed in claim 2 also comprises:

Screw rod, so that can be around the rotation of the axis that parallels with described orientation, and this screw rod has threaded portion by described stent support for it, the length of this threaded portion equals or is longer than described arrangement scope;

Screwing element, it is fixed to described support component and is bonded on this screw rod; With

Drive source, it provides forward and reverse rotation to this screw rod.

7. charging device as claimed in claim 3 also comprises:

Screw rod, so that rotate freely around the axis that parallels with described orientation, and this screw rod has threaded portion by described stent support for it, the length of this threaded portion equals described arrangement scope at least;

Screwing element, it is fixed to described support component and is bonded on this screw rod; With

Drive source, it provides forward and reverse rotation to this screw rod.

8. charging device as claimed in claim 1, wherein said cleaning member is set to holding fix, and this wait position is in the described orientation scope outside the image forming area of described photosurface.

9. charging device as claimed in claim 1, wherein said cleaning member is made by the resilient material that comprises polishing material, and the hardness of this polishing material is lower than the hardness of the raw material of described pin.

10. one kind is carried out the image forming apparatus that image forms by light activated element by electrophotographic method, comprises charging device as claimed in claim 1.

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