JPH0569971A - Electrophotographic printing device - Google Patents

Abstract

PURPOSE:To operate an electrophotographic printing device in appropriate condition by forming two friction faces of different friction coefficient on the fixed separation member oppositely contacted with the rotating separation roller of a paper feed part, and controlling a selection solenoid to selectively contact oppositely the two friction faces with the rotating separation roller from an information processing device according to a used printing paper sheet. CONSTITUTION:Two friction faces of different friction coefficient are formed on the fixed separation member oppositely contacted to the rotating separation roller of a paper feed part, and a selection solenoid to selectively contact oppositely the two friction faces with the rotating separation roller is controlled from an information processing device according to a used printing paper sheet. As a result of this, the characteristic of a paper sheet separation device can be easily fitted to diversification of the used paper sheet for electrophotographic printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printer, and more particularly to an improvement of a sheet separating means for transferring a toner image.

[0002]

2. Description of the Related Art A laser printer in an electrophotographic printing apparatus includes a charging device, a laser beam exposing device, a laser beam exposing device, a photosensitive drum, a photosensitive drum, a photosensitive drum, a photosensitive drum, a toner image, a toner image formed by an electrophotographic process, and a toner image formed on the paper. Arrange the developing device, transfer device, residual toner cleaner, residual charge cleaner,
After uniformly charging the surface of the photosensitive drum, the surface of the photosensitive drum is exposed by a laser beam modulated according to an image information signal to form an electrostatic latent image, and the surface of the photosensitive drum is developed to form a toner image, The toner image is transferred onto a sheet and fixed. The image information signal to be printed is created according to the input from a keyboard or the like by utilizing the document editing function and the video data generating function of an information processing device such as a word processor or a personal computer.

In such an electrophotographic printing apparatus, a sheet on which a toner image is transferred is extracted from a cassette and supplied, but if a plurality of sheets are simultaneously extracted and supplied at the time of this extraction, a paper feeding problem or printing may occur. A sheet separating device is used to prevent the double feeding of the sheets extracted from the cassette because they cause defects. The paper separating device has a structure in which a rotary separating roller is abutted on a fixed separating member having a friction surface formed on the surface thereof. The sheet of (double feed) is stopped by the frictional resistance of the fixed separation member, and only the uppermost sheet is fed out.

By the way, the type of paper used in the electrophotographic printing apparatus is limited to a range suitable for the performance of the apparatus. If a paper out of the range is used, not only a printed matter having a desired image quality cannot be obtained, but also a trouble occurs in the paper conveying system. Especially, the paper separating device is greatly affected.

One of the compatibility between the sheet separating device and the sheet is the relationship between the friction surface state of the fixed separating member and the surface state (smoothness) of the sheet. It is necessary to use a fixed separating member having a friction surface commensurate with the smoothness of the surface. When using paper with low smoothness (for example Japanese paper), a fixed separation member with a friction surface with a small friction coefficient is suitable, and for paper with high smoothness (paper), a fixed separation member with a large friction coefficient is suitable. Is.
If a fixed separation member with a large friction coefficient is used to separate Japanese paper with a low degree of smoothness, the frictional force will become excessive and the amount of paper dust generated will increase. Performance decreases. Therefore, frequent cleaning work is required to maintain these performances. By the way, the smoothness of general printing paper (paper) is 20 to 30 seconds, while the smoothness of shishi paper (Japanese paper) is 7 to 10 seconds.

Generally, the electrophotographic printing apparatus is configured to have specifications suitable for obtaining a printed matter using foreign paper, but the application for printing with a cursive typeface or the like on the paper is increasing. Naturally, the backing paper is Japanese paper, and if a general electrophotographic printing device is used for the printing as it is, a large amount of paper dust is generated in the paper separating device, and an obstacle due to the paper dust occurs. For example, in the case of printing on 3000 to 5000 sheets of paper for a day, it is necessary to carry out a paper dust cleaning operation every day in order to prevent the occurrence of paper dust trouble, which is a heavy burden on the user.

At the time of printing using paste paper, the fixed separating member of the paper separating device may be replaced with one suitable for the paste paper. However, in the case where printing on ordinary paper and printing on paste paper are frequently repeated, this Replacement work is also a heavy burden. Moreover, in this type of electrophotographic printing apparatus handled by an unspecified number of persons, there is a high possibility of neglecting or forgetting the replacement work, and it has been difficult to always operate the electrophotographic printing apparatus in an appropriate state.

It is to be noted that a fixed separating member having a plurality of friction surfaces having different friction coefficients is used and the friction surfaces are switched according to the type of paper, as disclosed in JP-A-60-10234.
There is No. 4 publication.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to easily adapt a sheet separating device of an electrophotographic printing apparatus to a variety of types of sheets used in the electrophotographic printing apparatus. Is to

[0010]

According to the present invention, there is provided a print information generating device for generating an image information signal to be printed, an electrophotographic process device for forming a toner image according to the image information signal, and a rotary separating member. A fixed separating member having a plurality of friction surfaces having different friction coefficients selectively contacting the rotating separating member, and separating the sheet to which the toner image is transferred by passing between the separating members. In the electrophotographic printing apparatus, the selection operation device is configured to switch the friction surface of the fixed separation member that contacts the rotation separation member according to the type of paper used, and the selection operation device is set to the print information. It is characterized in that it is configured to respond to the used paper information from the generator.

[0011]

The selecting operation device executes the selecting operation of the friction surface of the fixed separating member in response to the used paper information given from the print information generating device so that the friction coefficient is adapted to the used paper. The electrophotographic printing apparatus can be operated in an appropriate state by a simple operation such as inputting paper information for printing the print data when inputting print information or inputting a print command to the print information generating apparatus.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 is a vertical sectional side view of the laser printer in the electrophotographic printing apparatus according to the present invention. In the laser printer 1, a charging device 12, a laser beam exposure device 13, a developing device 14, a transfer device 15, a residual toner cleaner 16 and a residual charge cleaner 17 are arranged around a photosensitive drum 11.
The surface of the photosensitive drum 11 is uniformly charged by a charger 12, and then the surface of the photosensitive drum 11 is exposed by a laser beam generated by a laser beam exposure device 13 according to an image information signal to form an electrostatic latent image. The surface of the drum is developed by the developing device 14 to form a toner image.

Paper feed cassettes 18 and 19 are provided in order to supply the paper on which the toner image is transferred, and the papers 20 and 21 accommodated in the paper feed cassettes 18 and 19 are selectively extracted by the extraction rollers 22 and 23. Extract and supply to the paper separator. The sheet separating device corresponding to the sheet feeding cassette 18 includes a rotation separating roller 24 and a fixed separating member 25 that is in contact with the rotating separating roller 24, and the sheet separating device corresponding to the sheet feeding cassette 19 includes a rotation separating roller 26 and the rotation separating roller. A fixed separation member 27 that contacts the roller 26 is provided.

The registration roller 28 receives the leading edge of the sheet sent from the sheet separating device, controls the shaping, and convey timing so that the toner image formed on the surface of the photosensitive drum 11 is aligned with the position of the transfer device 15. To control. The sheet of which the posture and the conveyance timing are controlled in this way is then conveyed to the transfer device 15 via the reversing roller 29, and while being conveyed while being in contact with the surface of the photosensitive drum 11, the transfer device 15 from the back surface thereof. A transfer electric field is applied to transfer the toner image on the surface of the photosensitive drum 11 to the surface of the sheet.
The fixing device 30 heats the sheet on which the toner image has been transferred to fix the toner image, and discharges the sheet after fixing to the tray 31.

The control device 32 exchanges signals with the information processing device and controls the various electrophotographic print executing means in the laser printer for image printing.

Details of the paper feed unit including the paper separating device will be described with reference to FIGS. Two paper cassettes 18,
Since the two sheet separating devices that are respectively provided opposite to 19 have the same configuration, the sheet separating device that is provided opposite to the paper feed cassette 18 will be described as an example here.

A paper feed motor (a clutch when driven from another drive source) 33 drives the rotary separation roller 24 via a drive shaft 34 and drives the extraction roller 22 via a drive belt 35. .. The fixed separation member 25 that contacts the rotation separation roller 24 is fixed to the switching shaft 36, and is pressed against the rotation separation roller 24 by the suspension springs 37 and 38. The fixed separation member 25 is configured such that one surface of the friction materials 25a and 25b having different friction coefficients is selectively brought into contact with the rotation separation roller 24 by rotating the switching shaft 36 by a selection solenoid 39.

FIG. 1 shows a control device 3 of the laser printer 1.
2 is an electric circuit diagram of the information processing apparatus 2 and the information processing apparatus. The control circuit 40 of the control device 32 of the laser printer 1 is mainly composed of a CPU and controls the various electrophotographic printing execution means. Here, the laser beam exposure device 13 and the paper feed motor 33 are used.
Also, the selection solenoid 39 is shown, and other execution means are omitted.

The control circuit 50 of the information processing apparatus has a CPU 51
A document is edited according to predetermined format information (paper size, paper direction, character string direction, character typeface, paper type, etc.), character data, or image data, which is configured mainly from the keyboard 52 via the keyboard controller 53. Is executed, the edited document data is accumulated in the memory 54, and is displayed on the CRT display 56 by the CRT controller 55. When a document print command is input from the keyboard 52, the document data to be printed is expanded into print dot data and stored in the memory 54, and the print dot data is converted into an image information signal via the printer controller 57. The control process given to the laser printer 1 is executed.

Referring to FIG. 5, the control process executed by the control circuit 40 of the control device 32 of the laser printer 1 and the control process executed by the CPU 51 of the control circuit 50 of the information processing device for such printing will be described. explain.

First, when the operator commands the document editing process to be printed from the keyboard 52 of the information processing apparatus, C
The PU 51 activates the document editing program and executes the formatting process 101 according to the document editing program. Next, the document input process 102 is executed. In the process, character data from the keyboard 52 and image data from the image reader are input and edited, and the edited document data is stored in the memory 54 together with the format information.

The print control processing of the document data is started by the operator inputting a print command from the keyboard 52. When the print command is input, the CPU 51
Executes a print request process 103 for transmitting a print request signal to the laser printer 1 through the printer controller 57, expands document data to be printed into print dot data according to format information, and stores the dot data in the memory 54. The data expansion processing 104 is executed.

When the control circuit 40 of the laser printer 1 receives the print request signal in the process 201, it starts the print preparation control process and transmits the print format information request signal 20.
Execute 2.

When the CPU 51 of the information processing device receives the print format information request signal in process 105, it acquires the paper size, paper direction, paper type (paper / Japanese paper) information from the format information of the document data to be printed. Then, the process 106 of transmitting this as print format information is executed.

When the control circuit 40 of the laser printer 1 receives the print format information in the process 203, it executes the cassette selection process 204 for selecting, for example, the paper feed cassette 18 in which the paper size, the paper direction and the paper type match. A friction surface selection process 205 for urging the selection solenoid 39 to select and operate the fixed separation member 25 so that the friction material 25a, which is suitable for the paper type (paper / Japanese paper) information, contacts the rotary separation roller 24 is executed. When the preparation for printing is completed in this way, a print dot data request signal transmission process 206 for image printing is executed.

The CPU 51 of the information processing apparatus executes processing 107
When the print dot data request signal is received by the memory 54,
The print dot data transmission process 108 for transmitting the print dot data that has been expanded is executed.

Then, the control circuit 40 of the laser printer 1
Is a laser beam modulation process 2 for receiving the print data and modulating the laser beam generated by the laser beam exposure device 13.
Execute 07.

In the above control processing, the dot data development processing 104 for developing the document data to be printed into dot data is performed by the control circuit 40 of the laser printer 1 and is stored in the memory in the control circuit. May be.

Further, the paper type information to be used is set at the start of the document editing, but it may be input from the keyboard 52 during the print preparation control.

[0030]

As described above, according to the present invention, the operation of selecting the friction material of the fixed separating member is performed so that the friction surface conforms to the used paper in response to the used paper information given from the print information generator. Therefore, the operator can operate the electrophotographic printing apparatus in an appropriate state by a simple operation such as inputting paper information for printing the print data when inputting print information or inputting a print command to the print information generating apparatus. You can

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a laser printer control device and an information processing device in an electrophotographic printing apparatus according to the present invention.

FIG. 2 is a vertical sectional side view of a laser printer in the electrophotographic printing apparatus according to the present invention.

FIG. 3 is a perspective view of a paper feeding unit according to the present invention.

FIG. 4 is a side view of a rotary separation roller and a fixed separation member in the paper separating apparatus according to the present invention.

FIG. 5 is a flowchart of a control process executed by the electrophotographic printing apparatus according to the present invention.

[Explanation of symbols]

 1 Laser Printer 11 Photosensitive Drum 18 Paper Feed Cassette 24 Rotating Separation Roller 25 Fixed Separation Member 25a, 25b Friction Material 39 Selection Solenoid 40, 50 Control Circuit 52 Keyboard

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location G03G 15/00 102 8004-2H 109 7369-2H 15/04 116 9122-2H

Claims (3)

[Claims] 1. A print information generating device for generating an image information signal to be printed, an electrophotographic process device for forming a toner image according to the image information signal, a rotary separating member and a rotary separating member selectively. A separation device having a fixed separation member provided with a plurality of friction surfaces having different friction coefficients, the separation device separating the paper to which the toner image is to be transferred by passing between the separation members, and the paper used. In the electrophotographic printing apparatus including a selection operation device that switches the friction surface of the fixed separation member that is in contact with the rotation separation member according to the type, the selection operation device is used paper information from the print information generation device. An electrophotographic printing apparatus, characterized in that it is configured to respond to the. 2. The electrophotographic printing apparatus according to claim 1, wherein the print information generating device includes a keyboard for inputting image editing information to be printed and paper information for printing the edited image information. 3. The edit information generating device according to claim 1, wherein the print information generating device edits the image information based on the document information and the paper information, and a keyboard for inputting the paper information for printing the document information. An electrophotographic printing apparatus comprising an apparatus and the selection operation apparatus control signal generating apparatus.