KR980010663A - A method of fixing an image forming apparatus employing an electrophotographic developing system - Google Patents

Abstract

TECHNICAL FIELD OF THE INVENTION

To a method for fixing a toner transferred onto a recording paper in an image forming apparatus employing an electrophotographic developing method.

Technical Problems to be Solved by the Invention

Providing a fixing method that can improve fixing properties when printing using thick paper or coated paper

The point of the solution of the invention

The manual fixing mode is checked every time the image is printed on one sheet of paper by the electrophotographic developing process, and if the manual fixing mode is set, the fixing step is performed again for the paper being fed manually do.

Important Uses of the Invention

And is used for improving fixability in an image forming apparatus employing an electrophotographic developing system.

Description

A method of fixing an image forming apparatus employing an electrophotographic developing system

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an image forming apparatus using an electrophotographic developing system, and more particularly, to a method of fixing toner transferred onto a recording sheet.

Generally, the electrophotographic developing method is widely employed in an image forming apparatus such as a copying machine, a laser beam printer (LBP), an LPH (LED Print Head) printer, a plain paper facsimile, and the like have. The process of the electrophotographic developing method is a process in which a continuous "charging" "Exposure" "phenomenon" "Warrior" "Settle ", and the like.

Such an electrophotographic processor will now be described with reference to FIG. 1, which shows a schematic engine structure of a conventional LBP as a cross-sectional view.

First, in the charging step, the photosensitive drum 100 is charged by the charger 102 so that a uniform charge is formed on the surface. Next, in the exposure step, the surface of the photosensitive drum 100 is exposed to image data by a laser scanner unit (128), thereby forming an electrostatic latent image. At this time, the laser beam L generated from the laser scanner unit 128 exposes the photosensitive drum 100 through the reflector 130.

In this state, the paper automatically fed from the paper feed cassette 114 is conveyed to the register roller 118 via the conveying rollers 120 and 122. In the manual paper feed mode, And the sheet is conveyed to the register roller 118 via the conveying roller 122. [ After the leading edge is aligned, the sheet conveyed to the register roller 118 in this manner starts to be conveyed to the transcribing machine 106 at the same time as the above-described exposure step is started. Here, whether or not manual feeding is confirmed by the manual paper feed sensor S provided on the paper feeding path from the manual paper feeding device 126 is checked. For example, a reflection type photo sensor may be used as the manual paper feed sensor S.

And the electrostatic latent image formed on the photosensitive drum 100 is developed by the toner supplied from the developing device 104 in the developing step to be converted into a visible image. Thereafter, the toner attached to the photosensitive drum 100 is transferred to the paper sheet by the transfer device 106 in the transferring step and transferred to the registration roller 110 and the heat roller (not shown) via the transfer belt 108 112). Next, the toner transferred onto the paper is fixed on the paper by the pressure and heat of the fixing device in the fixing step. The paper thus fixed is discharged to the outside of the printer by the discharge roller 124, thereby completing printing on one sheet of paper.

Here, the fixing property of the sheet is determined according to the condition of the fixing unit. Normally, the condition of the fixing unit is set on the basis of the plain sheet. Therefore, there is no problem in printing using plain paper. However, when printing is performed using thick paper or coating paper, the fixing is not performed properly and becomes uneven.

As described above, conventionally, in the case of printing using thick paper or coated paper, the fixability is lowered, and the fixation is not performed properly or is uneven.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a fixing method capable of improving fixability when printing using thick paper or coated paper.

FIG. 1 is a sectional view showing a schematic engine mechanism structure of a conventional laser beam printer to which the present invention is applied; FIG.

FIG. 2 is a circuit block diagram of a conventional laser beam printer for carrying out the present invention. FIG.

3 is a flow diagram according to an embodiment of the present invention;

In order to accomplish the above object, the present invention provides a method and apparatus for confirming whether or not a manual fixing mode is set each time an image is printed on a single sheet of paper by an electrophotographic developing process, The fixing step is performed again in the process.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and accompanying drawings, numerous specific details, such as specific circuit configurations and elements, are set forth in order to provide a more thorough understanding of the present invention. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. Further, the detailed description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted. For convenience of explanation, an example in which the present invention is applied to the LBP which is one of the image forming apparatuses as described above will be described.

2 is a circuit block diagram of a typical LBP for carrying out the present invention and includes a video controller 200, an operating panel (OPE) 202, a print engine 204, .

First, the video controller 200 includes a computer interface 206, a video controller 208, and an engine interface 210, and is connected to the OPE 202 and the print engine 204. The computer interface 206 provides an interface to the transmit and receive signals between a host computer (not shown) such as a personal computer and the video controller 208. The video controller 208 communicates with the host computer and controls the print engine 204 according to various commands input from the host computer and the OPE 202 to perform various functions including image printing. At this time, the video control unit 208 generates image data to be printed from the data received from the host computer and provides it to the print engine 204. [ The engine interface 210 provides an interface to the transmit and receive signals between the video controller 208 and the print engine 204.

The OPE 202 is connected to the video control unit 208 and includes a plurality of keys for inputting various commands to the video control unit 208 and a control unit 208 for controlling the video control unit 208, And a display device.

The print engine 204 includes a video interface 212, an engine control unit 214, an I / O interface 216, a sensor circuit 218, a mechanism driving unit 220, and an electrophotographic developing unit 222 And is connected to the video controller 200. The video interface 212 provides an interface for transmitting and receiving signals between the video controller 200 and the engine controller 214. The engine control unit 214 controls the mechanism driving unit 220 and the electrophotographic developing unit 222 under the control of the video controller 200 to print an image according to the image data received from the video controller 200 on the paper, The operation state of each part of the print engine 204, the feeding and feeding state of the paper, and the amount of the developer are monitored through the sensor circuit 218. The I / O interface 216 is connected between the engine control unit 214 and the sensor circuit 218, the mechanism driving unit 220 and the electrophotographic developing unit 222 to interface the input / output signals of the engine control unit 214. The sensor circuit 218 drives various sensors for monitoring the operation state of each part of the print engine 204, the paper feeding and feeding state, the developer amount, and the like, including the above-described manual paper feed sensor S of FIG. And provides sensing signals of the respective sensors to the engine control unit 214. The apparatus driving unit 220 drives various apparatuses for feeding, conveying and printing the paper according to the control of the engine control unit 214. [ The electrophotographic developing unit 222 is controlled by the engine control unit 214 to print an image according to the image data by the mechanism of Fig.

The present invention applied to the above-described LBP allows a user to set a manual fixing mode when printing using thick paper or coated paper, and when the manual fixing mode is set, printing on one sheet is completed The fixing step is performed again for the paper to be fed manually. That is, if the user manually feeds the printed sheet again when printing on thick paper or coated paper, fixing is performed twice on the same paper, so that fixing performance can be improved.

FIG. 3 shows a flowchart according to the embodiment of the present invention. When the image is printed on one sheet of paper by the electrophotographic development process, whether or not the manual fixing mode is set is confirmed, The fixing step is performed again for the paper to be fed manually. The function according to FIG. 3 is programmed to be performed by the engine control unit 214.

Now, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG. The engine control unit 214 starts printing in accordance with the print command from the video control unit 208 and controls the mechanism driving unit 220 and the electrophotographic developing unit 222 in step 300 so as to perform a normal electrophotographic process An image is printed on one sheet of paper by a developing process. At this time, when printing on one sheet of paper is completed, the engine control unit 214 confirms whether the manual fixing mode is set in the video control unit 208 in step (302). The manual fusing mode is set by a key input of the OPE 202 when a thick paper or a coated paper is used for printing. If the manual fixing mode is not set, the engine control unit 214 ends the printing for one sheet of paper. Otherwise, if the manual fixing mode is set, the engine control unit 214 checks whether the manual feeding is performed by checking the state of the manual paper feeding sensor S through the sensor circuit 218 in step (304). In this case, if the user who has set the manual fixing mode has completed the printing just before and feeds the discharged paper sheet again through the manual paper feeder 126, the engine control unit 214 controls the fixing step Is performed again.

Therefore, when printing is carried out using thick paper or coated paper, fixation is improved by fixing twice.

Meanwhile, since the fixing step is performed in step 306, it is necessary to clean the surface of the photosensitive drum 100 to prevent unnecessary contamination of the paper. The engine control unit 214 controls the electrophotographic developing unit 222 to apply only the charging voltage and the cleaning voltage to the photosensitive drum 100 to maintain the surface potential of the photosensitive drum 100 constant.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. In particular, although the embodiments of the present invention are applied to the LBP of the present invention, they are equally applied to image forming apparatuses such as LED printers and plain paper facsimiles employing an electrophotographic process. In addition, although the manual fixing mode is selectively set by the user, the thickness of the fed paper is detected by using a conventional paper thickness sensing device, and the manual fixing mode is automatically set when the thickness of the paper is equal to or greater than a preset value You may. Accordingly, the scope of the invention is not to be determined by the embodiments described, but should be determined by the scope of the appended claims and equivalents of the claims.

As described above, the present invention has an advantage that fixation can be improved by fixing two times when printing using thick paper or coated paper.

Claims (6)

A method of fixing an image forming apparatus employing an electrophotographic developing method, the method comprising the steps of: printing an image on one sheet of paper by the electrophotographic developing method; Determining whether or not the fixing mode is set; and performing the fixing step again during the process for the paper to be fed manually when the manual fixing mode is set. The fixing method according to claim 1, wherein the surface potential of the photosensitive drum of the image forming apparatus is kept constant when the fixing step is performed again. The fixing method according to claim 1, wherein when the fixing step is performed again, only the charging voltage and the cleaning voltage are applied to the photosensitive drum to maintain the surface potential constant. The fixing method according to claim 1 or 2, wherein the manually fed paper is a paper that has been printed just before. 5. The method of claim 4, wherein the manual settlement mode is selectively set by a user. The fixing method according to claim 4, wherein the manual fixing mode is automatically set when the thickness of the paper is equal to or greater than a preset value. ※ Note: It is disclosed by the contents of the first application.