KR20060122794A - Image forming device and image forming process - Google Patents

Abstract

An image forming apparatus and an image forming method are provided to prevent the formation of an image when the skew of the print paper exceeds a predetermined range. A developing process member(30) includes plural developing process rollers(32) and coats the developing agent on the print paper so that an image is formed. The developing process roller includes a photosensitive medium(33), a developing roller(35), a transfer roller(37), an electrification roller(34) and a supply roller. The photosensitive medium sequentially passes the developing roller, the transfer roller and the electrification roller. The photosensitive medium receives the scanned light so that a latent image is formed. The developing roller coats the developing agent on the latent image and performs a developing process. The transfer roller transfers the developing agent to the print paper. A cleaning member(34a) removes the remaining developing agent from the photosensitive medium.

Description

Image forming apparatus and image forming method {IMAGE FORMING DEVICE AND IMAGE FORMING PROCESS}

1 is a schematic diagram showing the generation of skew of printing paper according to a conventional image forming apparatus;

2 is a block diagram showing an image forming apparatus according to an embodiment of the present invention;

3 is a schematic view showing a developing process part of FIG.

4 is a flowchart illustrating an image forming method according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

1: Image forming apparatus 10: Control unit

12: signal generator 14: storage unit

20: potential difference forming portion 30: developing process portion

32: developing process roller 40: conveying part

50: skew detection unit 60: source power supply

70: switching unit 80: image information supply unit

The present invention relates to an image forming apparatus and an image forming method, and more particularly, to a forming image forming apparatus and an image forming method capable of preparing for skew generation of printing paper.

In general, an image forming apparatus has a developing process portion having a plurality of developing process rollers, and a conveying portion for feeding printing paper into the developing process portion. The developing process unit selectively applies a developer to the printing paper fed by the conveying unit to form an image.

1 is a schematic diagram showing the generation of skew of printing paper according to a conventional image forming apparatus. As shown, the conventional image forming apparatus 100 includes a developing process unit 130 and a conveying unit 140. The conveying unit 140 conveys the printing paper P in a predetermined conveying direction d. The conveyer 140 feeds the printing paper P to the developing process unit 130 in a state N in which the side direction is parallel to the conveying direction d. The developing process unit 140 forms an image by applying a developer to a predetermined area A of the printing paper P so as to be suitable for the printing paper P fed in the normal state N. FIG.

However, in the process of the transfer unit 140 picking up the printing paper P, the printing paper P may be shifted from the conveying direction d due to the inclination of the printing paper P or various other causes. P) may be fed to the developing process unit 130 in an inclined state (S). That is, skew of the printing paper P may occur.

The developing process unit 130 forms an image in the predetermined area A, similarly to the printing paper P fed in the normal state N, even in the printing paper P fed in the state S where skew has occurred. Therefore, the image is formed obliquely on the printing paper (P) may reduce the print quality. As the skew occurs severely, when the inclination angle of the image formed on the printing paper P is severe, reprinting may occur, and waste of developer and printing paper may be caused.

It is therefore an object of the present invention to provide an image forming apparatus and an image forming method which can prevent an image from being formed when a skew of printing paper occurs to exceed an allowable range.

The above object is an image forming apparatus comprising a developing process portion having a plurality of developing process rollers and a conveying portion for conveying printing paper via the developing process portion, in accordance with the present invention, wherein the developing process is carried out by the conveying portion. A skew sensing unit sensing skew of the printing paper fed into the negative; A potential difference forming unit for forming a predetermined potential difference between the developing process rollers so that a developer is coated on printing paper; And a control unit which blocks the potential difference forming unit from forming the potential difference when the skew of the printing paper is out of a predetermined allowable range.

A source power supply unit supplying source power to the potential difference forming unit, and a switching unit electrically interposed between the source power supply unit and the potential difference forming unit, wherein the controller is configured to switch the controller when the skew of the printing paper is within the allowable range. And a signal generator for generating an on signal for shorting a part and an off signal for opening the switching part when the skew of the printing paper is out of the allowable range.

And an image information supply unit for supplying original image information to the developing process unit, wherein the control unit may include a storage unit for storing the original image information to be printed when the skew of the printing paper is out of the allowable range. .

The control unit causes the conveying unit to feed the next printing sheet into the developing process unit so that the original image to be printed is formed on the sheet of paper if the skew of the sheet of paper falls outside the allowable range, and the document stored in the storage unit is stored. Image information can be supplied to the developing process unit.

According to the present invention, an image forming method comprising the step of forming a predetermined potential difference in a plurality of developing process rollers such that the developer is moved by an electric force, the printing paper in the developing process unit having the developing process rollers Feeding paper; Detecting skew of the printing paper; Blocking the potential difference between the developing process rollers if the skew of the printing paper is out of a predetermined allowable range; And receiving and conveying the printing paper, to which the developer is not applied, from the developing process unit.

Supplying original image information to the developing process unit, and storing original image information to be printed when skew of the printing paper is out of the allowable range.

According to the present invention, there is provided an image forming method of an image forming apparatus, comprising the steps of: determining whether a change direction of a recording medium coincides with a predetermined conveyance direction within a predetermined allowable range; Applying a developer to the recording medium when the recording medium coincides with the conveying direction and within the allowable range; And when the recording medium is out of the allowable range in the conveying direction, blocking the application of the developer to the recording medium.

And supplying a next recording medium when the recording medium is out of the allowable range in the conveying direction; Determining whether the changing direction of the next recording medium matches the conveying direction within an acceptable range; Applying a developer to the next recording medium when the next recording medium coincides with the conveying direction and within the allowable range; Preferably, when the next recording medium is out of the allowable range in the conveying direction, blocking the application of the developer to the recording medium.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

2 is a block diagram illustrating an image forming apparatus according to an exemplary embodiment of the present invention, and FIG. 3 is a schematic diagram illustrating a developing process unit of FIG. 2. As shown, the image forming apparatus 1 has a developing process unit 30, a potential difference forming unit 20, a conveying unit 40, a skew detecting unit 50, and a control unit 10.

The developing process unit 30 includes a plurality of developing process rollers 32 and applies a developer T to form an image on the printing paper P. FIG. The developing process roller 32 has a photosensitive member 33, a developing roller 35, a transfer roller 37, a charging roller 34 and a supply roller. The photosensitive member 33 passes through the developing roller 35, the transfer roller 37, and the charging roller 34 in order.

The photosensitive member 33 receives the light scanned by the photoreceptor unit (not shown) to form an electrostatic latent image. The developing roller 35 applies the developer T to the electrostatic latent image formed on the photosensitive member 33 and develops it. The transfer roller 37 transfers the developer T applied to the photosensitive member 33 to the printing paper P which is advanced between the photosensitive member 33 and the transfer roller 37 by the conveyance unit 40. The cleaning part 34a removes the residual developer T remaining after being transferred to the printing paper P from the photosensitive member 33. The charging roller 34 charges the photosensitive member 33 so that the photosensitive member 33 has a uniform electric potential.

The developer storage unit 38 stores the developer T, and the supply roller 36 receives the developer T from the developer storage unit 38 and supplies the developer T to the developer roller 35. The agitator 38a stirs and conveys the developer T in the developer storage portion 38 to promote the transfer of the developer T to the supply roller 36. The doctor blade 39 adjusts the amount of the developer T supplied by the developing roller 35 to the photosensitive member 33. The photosensitive member 33, the developing roller 35, the supply roller 36, the transfer roller 37, the charging roller 34, and the agitator 38a are rotated by a drive unit (not shown).

The potential difference forming unit 20 forms a predetermined potential difference between the plurality of developing process rollers 32 so that the developer T is applied to the printing paper P. FIG. When the source power source 60 supplies the source power, the potential difference forming unit 20 transforms and distributes the source power to the photosensitive member 33, the developing roller 35, the supply roller 36, the transfer roller 37, and the charging roller. 34 each have a predetermined potential different from each other.

As the potential difference forming unit 20 forms a predetermined potential in each developing process roller 32, the developer T is moved from the supply roller 36 to the developing roller 35 by the electric force, and then the developing roller 35 ) To the photosensitive member 33, and finally may be applied to the printing paper P from the photosensitive member 33. In addition, the charging roller 34 may be the static electricity to the photosensitive member 33, the doctor blade 39 is able to adjust the amount of the developer (T).

The conveying section 40 conveys the printing paper P so as to pass through the developing process section 30. The conveyance section 40 feeds the developing process section 30 so that the printing paper P travels between the photosensitive member 33 and the transfer roller 37. The conveyance part 40 receives printing paper P from the developing process part 30, and conveys it to a fuser (not shown). The fixing unit (not shown) may fix the developer T coated on the printing paper P to the printing paper P.

The conveyance part 40 receives printing paper P from the developing process part 30, and conveys it regardless of whether the developing process part 30 apply | coated the developer T. When printing paper P is normally fed to developing process part 30, conveyance part 40 conveys printing paper P to which developer T was apply | coated. When skew occurs on the printing paper P out of a predetermined allowable range, the conveying unit 40 conveys the printing paper P as it is fed to the developing process unit 30 because the developer T is not coated. do.

The skew detecting unit 50 detects the skew of the printing paper P fed into the developing process unit 30 by the conveying unit 40. The skew detecting unit 50 detects the inclination of the printing paper P fed into the developing process unit 30, that is, skew, and transmits the skew to the control unit 10. The skew detecting unit 50 may detect the degree of skew by measuring the gap between the front edges of the front end side of the printing paper P entering the developing process unit 30, that is, the top skew. Alternatively, the skew detecting unit 50 may detect the degree of skew by measuring a side street gap, that is, side skew, at both edges of one edge of one side of the printing paper P. The skew detecting unit 50 may use a conventional unit capable of detecting skew of a contact image sensor (CIS), a charge coupled device (CCD), or a printing paper (P).

The control unit 10 compares the skew information of the printing paper P received from the skew detecting unit 50 with a predetermined allowable range, and if the skew of the printing paper P is out of the predetermined allowable range, the potential difference forming unit 20 ) Prevents the developer T from being applied to the printing paper P by blocking the formation of the potential difference. At this time, the conveyance unit 40 receives the printing paper P in the state where the developer T is not applied from the developing process unit 30 and conveys it. On the other hand, the control unit 10 causes the developer T to be applied to the printing paper P so that the potential difference forming unit 20 normally forms the potential difference when the skew degree of the printing paper P is within a predetermined allowable range. The predetermined skew allowance range may be previously stored in the controller 10 or input by the user through a user interface (not shown).

The control unit 10 has a signal generation unit 12 that generates a signal to control the switching unit 70. The control unit 10 controls the potential difference forming of the potential difference forming unit 20 by intermittently controlling the switching unit 70 by the signal generation unit 12. The signal generator 12 generates an on signal Von when the skew of the printing paper P is within the allowable range, and generates an off signal Voff when the skew of the printing paper P is out of the allowable range. The signal generator 12 may generate an on signal Von and an off signal Voff by generating signals having different voltages. Alternatively, the signal generator 12 may generate the on signal Von and the off signal Voff from each other by different currents or similar methods.

The switching unit 70 is electrically interposed between the source power supply unit 60 and the potential difference forming unit 20. When the switching unit 70 receives the ON signal Von from the signal generation unit 12, a short circuit occurs between the source power supply unit 60 and the potential difference generation unit 20 so that the source power supply is supplied to the potential difference generation unit 20. do. Accordingly, the potential difference forming unit 20 may transform and distribute the source power to form a predetermined potential in each of the developing process rollers 32. When the switching unit 70 receives the off signal Voff from the signal generation unit 12, the source power unit 60 is opened between the source power unit 60 and the potential difference forming unit 20 so that the source power is not supplied to the potential difference forming unit 20. Don't let that happen.

The switching unit 70 may be a conventional electric circuit that may be a short circuit or an open circuit according to the input signal. The switching unit 70 may prevent the potential difference forming unit 20 from forming a potential difference in the developing process roller 32, as well as between the source power supply unit 60 and the potential difference forming unit 20. ) And the developing process unit 30 or may be located inside the potential difference forming unit 20.

The image information supply unit 80 supplies original image information to the developing process unit 30. The developing process unit 30 forms the original image on the printing paper P in accordance with the original image information supplied by the image information supply unit 80. The image information supply unit 80 may be an external computer (not shown) or an image processor that receives data from an external computer (not shown) and translates the data into an image. Alternatively, the image information supply unit 80 may be a storage unit (not shown) in which predetermined image information is stored.

The control unit 10 has a storage unit 14 capable of storing an original image supplied by the image information supply unit 80 to the developing process unit 30. The control unit 10 stores the original image information to be printed in the storage unit 14 when the skew of the printing paper P is outside the allowable range. The control unit 10 causes the conveying unit 40 to feed the next printing paper P to the developing process unit 30, and supplies the original image information stored in the storage unit 14 to the developing process unit 30. . At this time, the skew detecting unit 50 may detect the skew of the next printing paper P supplied to the developing process unit 30. If the skew of the next printing paper P is out of the allowable range, the controller 10 may block the potential difference forming of the potential difference forming unit 20 and repeatedly store the original image information in the storage unit 14.

Accordingly, if the skew of the printing paper P is out of the allowable range, the signal generation unit 12 generates the off signal Voff, and the switching unit 70 is opened, thereby preventing the image from being formed on the printing paper P. By storing the unprinted original image information while supplying it to the developing process unit 30 again, the original image not printed due to the skew can be printed on the printing paper P.

When the skew of the printing paper P is out of the allowable range, the conveying unit 40 returns the printing paper P received from the developing process unit 30 again without the developer T applied thereto. 30) can also be fed.

The image forming apparatus 1 may have an output unit (not shown), and the controller 10 may display that an image is not formed through the output unit (not shown) when the skew is outside the allowable range. In this case, it is preferable to display the printing paper on which the image is not formed to be specified.

4 is a flowchart illustrating an image forming method according to an exemplary embodiment of the present invention. As shown, the image forming method starts by supplying document image information to a developing process having a developing process roller (S10), and forming a predetermined potential difference between the developing process rollers so that the developer is moved by an electric force. (S20). The step S10 of supplying the original image information and the step S20 of forming a predetermined potential difference may be performed in the reverse order or simultaneously.

Next, the printing paper is fed to the developing process unit and the skew of the printing paper is detected (S30). The degree of skew of the printing paper is compared with the predetermined allowable range (S40). If the skew of the printing paper is out of the predetermined allowable range, the potential difference between the developing process rollers is blocked. (S50) This prevents the developer from moving between the developing process rollers, thereby preventing the developer from being applied to the printing paper. Then, the document image information to be printed is stored (S60) and the printing paper which is not coated with the developer is received from the developing process unit and returned. (S70) The step of storing the original image information (S60) and conveying the printing paper S70 may be reverse or simultaneous. Then, the stored original image information is supplied to the developing process unit (S80), and the steps of forming the potential difference (S20) and printing paper feeding (S30) again are repeated to print an image not printed by skew.

When the degree of skew of the printing paper is judged (S40) and the degree of skew is within a predetermined allowable range, an image is formed on the printing paper (S90) and the printing paper on which the image is formed is received from the developing process unit and returned (S100) The image forming method ends.

The image forming method according to an embodiment of the present invention may form an image on a single printing paper or a plurality of printing papers. When an image is formed on a plurality of printing sheets, the document image information supplying step S10 to the printing sheet conveying step S100 may be repeatedly performed.

As can be seen from above, the image forming apparatus and the image forming method according to the present invention prevent the developer from being applied to the printing paper by removing the potential difference between the developing process rollers when the skew of the printing paper occurs outside the predetermined range. Accordingly, it is possible to prevent waste of developer, printing paper, and printing time by preventing the image from being formed obliquely on the printing paper.

Claims (2)

An image forming method comprising the step of forming a predetermined potential difference in a plurality of developing process rollers so that a developer is moved by an electric force, Feeding a sheet of printing paper to a developing process unit including the developing process roller; Detecting skew of the printing paper; Blocking the potential difference between the developing process rollers if the skew of the printing paper is out of a predetermined allowable range; And And conveying the printing paper to which the developer is not applied. The method of claim 1, Supplying original image information to the developing process unit, and storing original image information to be printed when skew of the printing paper is out of the allowable range.

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