CN1206128A - Method of preventing back side of paper from contamination in electrophotography printer - Google Patents
Method of preventing back side of paper from contamination in electrophotography printer Download PDFInfo
- Publication number
- CN1206128A CN1206128A CN 97115024 CN97115024A CN1206128A CN 1206128 A CN1206128 A CN 1206128A CN 97115024 CN97115024 CN 97115024 CN 97115024 A CN97115024 A CN 97115024A CN 1206128 A CN1206128 A CN 1206128A
- Authority
- CN
- China
- Prior art keywords
- photosensitive drum
- paper
- transfer roll
- toner
- exposure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Control Or Security For Electrophotography (AREA)
- Combination Of More Than One Step In Electrophotography (AREA)
- Discharging, Photosensitive Material Shape In Electrophotography (AREA)
Abstract
A method of protecting the back side of a paper from contamination in an electrophotographic printer is disclosed, in which its light scanning unit is warmed up as the main motor operates, to minimize the potential difference on the surface of the photosensitive drum, and 0 or (-) voltage is applied to its transfer roller to prevent the toner, which adheres to the photosensitive drum, from adhering to the transfer roller before a paper reaches the transfer roller, to thereby protect the back side of the paper from contamination due to the toner.
Description
The present invention relates to control the method for electrophotographic printer, particularly in electrophotographic printer, prevent to pollute the method for back side of paper.In order on the photosensitive drum surface, to form minimum potential difference (PD), in electrophotographic printer, allow its light scanning unit (LSU) preheating when the rotation of main motor, and before arriving transfer roll, paper is attached on the transfer roll in order to stop attached to the toner on the photosensitive drum, allow transfer roll be in zero potential or negative potential, prevent that whereby back side of paper is subjected to toner contamination.
The electrofax treatment facility utilizes the electrostatic latent image absorption toner that forms according to the potential difference (PD) on the photosensitive drum to form visual image, and then is fixed on the paper by this visual image of fusion.This electronic camera technology comprises: charging technique is used to the photosensitive drum charging; Exposure technique, exposure forms electrostatic latent image on charged photosensitive drum surface; Visualization techniques utilizes developer that the electrostatic latent image on the photosensitive drum is become visual image; Transfer techniques goes the image transfer on the photosensitive drum to paper.
As an example of electronic camera technology, introduce laser printer below.The exposure technique of laser printer comprises the application technology of light emitting diode (LED) application technology and laser scan unit (LSU).The present invention is used to adopt the electrofax treatment facility of LSU.
Fig. 1 is the print procedure of conventional laser printer.With reference to Fig. 1, print procedure comprises three steps: the paper 300 that the first step (A1) will leave in the carton 1 offers printer by getting paper bowl; Second step (A2) was utilized charging, exposure, developing and shifting process that the electrostatic latent image that forms on the photosensitive drum 2 is transferred to paper 200 to get on; The 3rd step (A3) utilized heating of hot pressing roller and pressurization to make toner fusion set on paper; Allow paper 100 send printer then, finish printing.
Fig. 2 represents the image transfer section on the conventional electrofax treatment facility.Image transfer section comprises: the photosensitive drum 1 that forms image thereon; Charging device 2 is used for to photosensitive drum 1 charging; Scanning element 3 utilizes the powered surfaces of photosensitive drum 1 to shift electrostatic latent image; Developing roller 5 utilizes toner compounds 4 to become toner image from electrostatic latent image; Stirrer 8 is used for the toner of toner hopper is mixed; Scraper plate 9, it is coated on the developing roller 5 toner equably; Clearer 10 is removed unnecessary toner from photosensitive drum 1; Carton 11 is used to deposit paper to be printed; Get paper bowl 12, it takes out paper and sends then from carton when receiving prearranged signals; Defeated paper sensor 14 is used to experience the paper of paper bowl 12 or artificial paper feed tray 13 asked for; Conveying roller 15 transmits and gets the paper that paper bowl 12 provides; Location dancer rools 16 is used to adjust the paper front edge that conveying roller 15 is brought.Charging device 2 does not contact with photosensitive drum 1 with transfer device 7.
The image conversion procedure declaration of electrofax treatment facility is as follows.Charging device 2 utilizes high voltage to make photosensitive drum 1 surperficial uniform charged (corona charging).Scanning element 3 will be transformed into light beam from the numerical signal of computing machine, form electrostatic latent image by scanning element 3 on photosensitive drum 1 surface.Developing roller 5 leans on very closely with the surface of photosensitive drum 1, and electrostatic latent image contacts with equally distributed toner thin layer on the developing roller 5, forms visual image.This visual image is transferred on the paper 6 by means of the high pressure of transfer device 7.Image on the paper passes through between the warm-up mill of fixing apparatus and compression roller, because heating and the fusion of squeezing action image are on paper 6.Send from printer by the outlet roller (not shown) then.
When artificial paper feeding, paper 6 is sent into from artificial paper feed tray 13, and sensor 14 is experienced after the paper, treatment facility master motor rotation, and main motor shuts down after conveying roller 15 captures paper.When receiving the data that computing machine begins to print, paper dancer rools 16 places, location sequence and wait by the time photosensitive drum can print image till, locate dancer rools 16 then and under the control of interrupter (not shown), move, whereby print image on paper.
When paper takes out when being sent to photosensitive drum 1 with getting paper bowl 12 from carton 11, photosensitive drum 1 rotates twice at least can reach print state, and location dancer rools 16 is not made other things except arranging paper.But when adopting artificial paper feeding, because the distance that paper is advanced is short, photosensitive drum does not have time enough to reach print state.Therefore, reach print state in order to make photosensitive drum in the shortest time, the location dancer rools is connected with interrupter, conveyance of sheets in the time that postpones.
Fig. 3 represents another kind of image transfer means, and it utilizes the mechanism of charging, transfer printing and the conveyance of sheets different with said apparatus.This device does not have clearer and alignment sensor, and charging is finished when photosensitive drum contacts with transfer roll 22 with the charging roller 21 of conduction with transfer process.
In this system that does not have an alignment sensor, have no idea to interrupt paper and transmit and enter the needed time of print state to satisfy photosensitive drum.With reference to Fig. 3, when beginning to print, paper is transported on the conveying roller 15 through getting paper bowl 12.Feeding sensor 14 is surveyed the position of paper, so that the parameter of photosensitive drum 1 works on predetermined sequential.That is to say that device brings into operation when sensor is experienced the leading edge of paper, and is different with system shown in Figure 2, this system just brings into operation when the interrupter of location dancer rools brings into operation.When adopting this system, when paper was sent from carton 11, the photosensitive drum rotation also reached print state before paper arrives.Therefore, can normally print and not interrupt.
But feeding sensor 14 is experienced paper and is placed on the artificial paper feed tray during artificial paper feeding, and main motor entry into service captures paper master motor until conveying roller 15 and shuts down.When beginning to print after the data of receiving from computing machine, main electric motor starting transmits paper simultaneously, so that contact feeding sensor 14 once more.Next the parameter that is photosensitive drum plays a role to finishing to print.Take place owing to main motor operation transmits simultaneously with paper, allow photosensitive drum enter print state so have no time.Therefore, toner between the LSU warming up period attached to photosensitive drum on, pollute paper.
Fig. 4 represents the universal architecture of LSU briefly.LSU comprises: laser emitting source 41, for example gas laser or semiconductor laser; Many ribs catoptron 42 of rotation, the light beam that speed is rotated and reflection laser 41 sends that it changes with per minute 2000 to 5000; Beam finder 43S and 43E survey many ribs catoptron 42 beam reflected; And photosensitive drum 1, on photosensitive drum, the surface potential of exposure area is different from the surface potential of unexposed area under many ribs mirror reflects light beam.Along with 42 rotations of many ribs catoptron, laser emitting source 41 emitted laser bundles make photosensitive drum 1 face exposure, make the surface potential difference of photosensitive drum zones of different according to desired images.Utilize many ribs catoptron 42 laser beam flying photosensitive drums 1, beam finder 43S and 43E are positioned at the starting point and the terminal point of beam, and the beginning of probe beam and termination.Between the LSU warming up period, many ribs catoptron 42 begins rotation and transmits light beam to beam finder 43S and 43E, rotates with normal speed until catoptron, prints the normal operation of beginning.Photosensitive drum exposure meanwhile.60 milliseconds of current classification durations, this is the shortest time that LSU finishes preheating.Require to confirm this preheating time that many ribs catoptron and beam finder reach normal speed, this time is differentiated with the preheating of laser emitting source.During the printing on the photosensitive drum line exposing time be 0.9 millisecond.Therefore, print the exposure that needs and to exceed 60 times with required the comparing of preheating.
Therefore, even after print job, passed through considerable time, still stay some electric charges on the photosensitive drum surface.Finish and normal running status when being confirmed in preheating, main motor begins to make the photosensitive drum rotation, though developing roller 5 this moment biasing not, because boundary effect also has the exposed portion that a spot of toner is attached to bulging face.When this part toner contacts with transfer roll, owing to transferring on the transfer roll in order to remove the residual toner of effect that remains in the voltage that the toner on the photosensitive drum applies.When paper passed through between photosensitive drum and transfer roll, toner polluted paper attached to the back side of paper.Allow the photosensitive drum rotation time several times if having, it is possible removing the toner that is attached on the transfer roll.But when artificial paper feeding, there is not time enough to rotate by photosensitive drum.
The purpose of this invention is to provide a kind of method and prevent that the paper in the electrophotographic printer from polluting, in the method during the scanning element preheating master's motor simultaneously in running, so that reduce the indicative of local optical consume of printing machine photosensitive drum, and on the opportunity that control applies voltage for its transfer roll, prevent that whereby back side of paper from polluting.
In order to finish this purpose of the present invention, provide in the electrophotographic printer that uses transfer roll and prevented the contaminated method of back side of paper, this method comprises the steps: to start main motor when the scanning element preheating, so that the potential difference (PD) that the photosensitive drum surface is set up minimizes, and before and after contacting with transfer roll, the exposure region (toner adheres on it) of photosensitive drum allow transfer roll be in zero potential or negative potential, time is △ T+2 α, wherein △ T is the time that the photosensitive drum exposure needs, α is the additional period of being scheduled to, and therefore stops the toner on the photosensitive drum to shift to transfer roll.
In order further to understand the present invention, some accompanying drawings are included and incorporate the present invention into as a part of the present invention.These description of drawings certain embodiments of the present invention, and principle of the present invention is described with character narrate.
Accompanying drawing comprises:
Fig. 1 is the working state figure of the image transfer process of routine;
Fig. 2 explanation has the structure of the laser printer of paper arranging functional;
Fig. 3 explanation does not have the structure of the laser printer of paper arranging functional;
Fig. 4 illustrates the structure of LSU briefly;
Fig. 5 is a sequential chart, and the potential difference (PD) on the conventional laser printer photosensitive drum is described;
Fig. 6 explanation is by the surface state of the photosensitive drum of potential difference (PD) foundation shown in Figure 5;
Fig. 7 is a sequential chart, and the potential difference (PD) of setting up on the photosensitive drum of laser printer according to the present invention is described;
The surface state of the photosensitive drum that Fig. 8 explanation is corresponding with Fig. 7;
Fig. 9 is the sequential chart of conventional laser printer;
Figure 10 is the sequential chart according to laser printer of the present invention;
Figure 11 illustrates the duty of photosensitive drum to the time.
With reference to the accompanying drawings to the embodiment preferred of the present invention explanation that makes an explanation.The potential difference (PD) that Fig. 5 explanation forms on the photosensitive drum of conventional laser printer.LSU one preheating, with regard to certain special part on the concentrated area scanning photosensitive drum, and the photosensitive drum charging voltage reaches-800V by the laser beam of many ribs mirror reflects.Therefore, △ T1 during this period of time in the current potential of photosensitive drum be-15V (△ T1 be from the moment that many ribs catoptron begins to rotate (t1) to the moment (t2) that obtains rated speed during this period of time), and form potential difference (PD) △ V on the surface of photosensitive drum.Because this potential difference (PD) forms sweep trace on the photosensitive drum surface, as shown in Figure 6.
For this reason, the photosensitive drum consume wants much serious, and pollution takes place at back side of paper.In Fig. 5, t1 points out the moment that photosensitive drum begins to expose between the LSU warming up period, t2 is meant the moment that photosensitive drum is finished exposure, main motor entry into service between the LSU warming up period, △ T1 represents the preheating time (T2-T1) of LSU, (A) be illustrated in the current potential on drum face when photosensitive drum exposes between the LSU warming up period, (B) be illustrated in the current potential of the maintenance on the photosensitive drum.
But, if master's motor is also in running during the LSU preheating, photosensitive drum T1 during the T2 also in rotation (as shown in Figure 7), the reduction of the potential difference (PD) on the photosensitive drum (△ V2) like this.In addition, because laser beam is at the surface scan of rotating photosensitive drum, so what swept to is the subregion of photosensitive drum, so the consume of the optics of photosensitive drum also is reduced.Scan pattern on the photosensitive drum as shown in Figure 8.Compare with the operation of routine, when photosensitive drum rotated, sweep trace no longer resembled and repeatedly is applied to same narrow zone shown in Figure 6, but covers the zone of a broad.Therefore the potential difference (PD) on the exposure area of photosensitive drum descends.Therefore the quantity that this has reduced the optics consume of exposed portion and has been attached to the toner of bulging face reduced the pollution of back side of paper greatly.
In other words, because the narrow and small zone on the surface of photosensitive drum is not always in exposure, therefore thereby reduced the consume on the photosensitive drum, reduced the quantity of transferring to the toner on the photosensitive drum and reduced pollution to transfer roll, this pollution is by causing attached to the toner on the photosensitive drum.When adopting artificial paper feeding, back side of paper does not pollute.
Even have only a spot of toner attached on the photosensitive drum, if apply positive voltage on transfer roll, toner also can be transferred to transfer roll and get on.In order to address this problem, on transfer roll, apply no-voltage or negative voltage, stop toner on transfer roll, to shift.
Fig. 9 is the operation sequential chart of each parts of conventional structure printer.With reference to Fig. 9, main motor starts after LSU preheating (about five seconds) is finished.After finishing, preheating is the transfer roll charging.Figure 10 is the parts operation sequential chart according to the printer of the present invention's making.With reference to Figure 10, when the LSU preheating, main motor rotation so that a bigger regional exposure is arranged, and during near transfer roll, imposes on transfer roll with no-voltage or negative voltage at exposed portion on the photosensitive drum surface.In other words, miss a period of time △ T2 and apply voltage to transfer roll afterwards, photosensitive drum is through overcharging during this period, and developing arrives transfer roll then.
Figure 11 represents the variation that the duty of photosensitive drum (goes out number) in time.This figure explanation charging (C), developing (D) and the required time △ T2 of transfer printing (T) process.As shown in figure 10, main motor and LSU move simultaneously, and apply no-voltage or negative voltage to transfer roll in after elapsed time △ T2, this voltage duration is △ T+2 α (wherein △ T is the time shutter of photosensitive drum), time △ T2 is that photosensitive drum forwards the used time of transfer roll to from exposure region, stop a spot of toner to be attached to the exposed portion of photosensitive drum whereby, pollute transfer roll.Utilize the present invention to prevent that the contaminated method in paper front from needing two steps.The first step allows main motor rotate between the LSU warming up period, so that have the zone of broad to be exposed on the photosensitive drum surface, thus make attached to the toner on the photosensitive drum minimum.In second step, before and after contacting with transfer roll, the photosensitive drum exposure region that has adhered to toner on transfer roll, applies no-voltage or negative voltage, and the duration is △ T+2 α.So, then just do not transfer on the transfer roll from the toner of photosensitive drum.
When LSU is used as the optical system of electrophotographic printer and independently the paper interrupting device is not controlled paper, utilize the present invention, can during artificial paper feeding, prevent that back side of paper from being polluted.In addition, when photosensitive drum stopped the rotation, the consume on photosensitive drum between the LSU warming up period can be lowered to bottom line.
So, be to be understood that the specific embodiment that the present invention is not limited to disclose here, it is as just the optimal mode of implementing to finish when of the present invention, and is interpreted as the present invention and is not subjected to except the claim that defines in appended claims the restriction of the specific embodiment narrated in this part detailed description.
Claims (4)
1. method that prevents that in utilizing the electrophotographic printer of transfer roll paper from polluting, this method is made up of following step:
When the scanning element preheating, allow main motor rotate, so that the potential difference (PD) minimum that forms on the photosensitive drum surface; And
The exposure region (toner adheres on it) of photosensitive drum with before transfer roll contacts and after, allow transfer roll be in zero potential or negative potential immediately, time is △ T+2 α, wherein △ T is the time that the photosensitive drum exposure needs, (α) be the additional period of being scheduled to, prevent that whereby the toner on the photosensitive drum from shifting to transfer roll.
2. according to the process of claim 1 wherein that electrophotographic printer does not use location dancer rools control paper sheet delivery.
3. repeat according to the process of claim 1 wherein that exposure does not concentrate on the narrow and small zone of photosensitive drum, to reduce its optics consume.
4. according to the process of claim 1 wherein that electrophotographic printer adopts artificial paper feeding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB971150249A CN1145081C (en) | 1997-07-22 | 1997-07-22 | Method of preventing back side of paper from contamination in electrophotography printer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB971150249A CN1145081C (en) | 1997-07-22 | 1997-07-22 | Method of preventing back side of paper from contamination in electrophotography printer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1206128A true CN1206128A (en) | 1999-01-27 |
| CN1145081C CN1145081C (en) | 2004-04-07 |
Family
ID=5173064
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB971150249A Expired - Fee Related CN1145081C (en) | 1997-07-22 | 1997-07-22 | Method of preventing back side of paper from contamination in electrophotography printer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1145081C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102073238A (en) * | 2011-01-04 | 2011-05-25 | 珠海赛纳打印科技股份有限公司 | Image forming device and method |
| CN103676564A (en) * | 2012-09-11 | 2014-03-26 | 株式会社理光 | Image forming device and transfer component cleaning method |
-
1997
- 1997-07-22 CN CNB971150249A patent/CN1145081C/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102073238A (en) * | 2011-01-04 | 2011-05-25 | 珠海赛纳打印科技股份有限公司 | Image forming device and method |
| CN103676564A (en) * | 2012-09-11 | 2014-03-26 | 株式会社理光 | Image forming device and transfer component cleaning method |
| CN103676564B (en) * | 2012-09-11 | 2016-01-27 | 株式会社理光 | Image processing system and transfer member clean method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1145081C (en) | 2004-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1101562C (en) | Imaging device and cleaning method of contact copying apparatus | |
| US5839026A (en) | Method of controlling charge voltage of image forming apparatus using electrophotographic developing process | |
| CN1145081C (en) | Method of preventing back side of paper from contamination in electrophotography printer | |
| EP0896254B1 (en) | Method for driving electrographic imaging apparatus | |
| US4647177A (en) | Electrophotographic copier | |
| US6954603B2 (en) | Fuser oil contamination prevention and clean-up method | |
| KR100199474B1 (en) | Method for preventing the back paper from being polluted for a laser printer's manual feeding | |
| US6690898B2 (en) | Image forming apparatus with movable cleaning element | |
| JP3414474B2 (en) | Toner density detection control method | |
| US7068959B2 (en) | Fuser oil contamination prevention and clean-up method | |
| JP4127644B2 (en) | Image forming apparatus | |
| JP3597273B2 (en) | Image forming device | |
| US5960235A (en) | Method for preventing contamination of photosensitive drum | |
| JPH08227189A (en) | Optimization of transfer rate for minimization of image smear | |
| JP3617915B2 (en) | Image forming apparatus | |
| JP3368114B2 (en) | Image forming device | |
| KR0160558B1 (en) | Control method for preventing pollution of contact charge | |
| CN1134707C (en) | Method and device for preventing formation of background image | |
| JP3115656B2 (en) | Image forming device | |
| JP3000936B2 (en) | Cleaning equipment | |
| JPH09244316A (en) | Image forming device | |
| JPH0830112A (en) | Electrophotographic device and electrophotographic method | |
| JPH02100065A (en) | Image forming device | |
| JPH06161193A (en) | Image forming device | |
| JPH0990702A (en) | Color image forming device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20040407 Termination date: 20100722 |