KR100433427B1 - Apparatus for sensing paper in an office machine - Google Patents

Abstract

The paper sensing device of the office equipment according to the present invention includes two sensor actuators installed to be rotated by the paper when the paper is conveyed, and a sensor unit for generating a paper sensing signal according to the rotation operation of the sensor actuator. According to the present invention, since two sensor actuators of the paper sensing device are configured to accurately detect the leading position of the paper regardless of the skew type or amount of the paper, the leading alignment and the leading margin of the paper to print the image are effectively controlled.

Description

Apparatus for sensing paper in an office machine}

The present invention relates to office equipment such as laser printers, copiers, and the like, and more particularly, to precisely detect the line unit value of the paper picked up by the pickup roller and then conveyed by the feed roller. The present invention relates to a paper sensing device of an office equipment that can effectively control a top margin.

In general, input / output devices such as inkjet printers, laser printers, facsimiles, etc., which perform printing using paper as a medium, have line unit values of the paper so as to control tip alignment and tip margin. A paper sensing device for sensing is provided.

For example, as shown in FIG. 1, the double-sided printing laser printer 1 is provided to the paper feed cassettes 11 and 11 'and the paper feed cassettes 11 and 11' which are detachably installed on the frame 10 of the main body. Pick-up / transport unit (6) for picking up and transporting the loaded paper (P), paper alignment unit (27) for aligning the leading end of paper (P) transported from the pick-up / transport unit (6), and pick-up / transport unit ( 6) and a paper sorting unit 27 arranged between the paper detecting unit 26 for detecting the line unit value of the paper P, the developing unit 30 for forming a toner image on the paper P, and the paper ( A fixing unit 40 for heating and compressing the toner image formed on P) to fix it as a visible image, a discharge unit 50 for discharging the paper P on which the visible image has been fixed by the fixing unit 40, and a sheet Develop paper P which has completed printing on one side through the fixing unit 40 in order to print an image on the back side of (P). And a duplex unit (80) for re-entry to the cut (30).

Each paper feed cassette 11, 11 'is installed at the lower portion of the frame 10 of the main body and elastically holds the paper P through a paper pressing plate (not shown) supported by an elastic spring (not shown). Support to get on and off.

On each of the paper feed cassettes 11 and 11 ', a pickup / transfer unit 6 for picking up and transporting the sheets P loaded in the paper cassettes 11 and 11' one by one is sequentially provided. The pickup / transfer unit 6 picks up the paper P loaded in the paper cassettes 11 and 11 ', and a paper sensor (not shown) that detects whether paper cassettes 11 and 11' are loaded. Pick-up roller 7 and transfer and backup rollers 23 and 24 for transferring the picked paper P to the developing unit 30 along the paper feed guide 22 constituting the paper feed path A. do.

The paper sorting unit 27 is composed of registers and backup rollers 28 and 29 for aligning the leading end of the paper P to be conveyed from the conveying and backup rollers 23 and 24.

In front of the register roller 28, that is, upstream of the sheet conveying direction of the register roller 28, a sheet detecting device 26 for detecting a line unit value of the sheet P is disposed.

In general, the paper sensing device 26 includes one sensor actuator (not shown) installed to resiliently rotate by the paper P when the paper P is conveyed through the register roller 28, And an optical sensor (not shown) for detecting an end position of the sensor actuator according to the rotation of the sensor actuator and sending a paper detection signal to a controller (not shown). The light sensor is usually composed of a light emitting portion for transmitting light, and a light receiving portion for receiving the light emitted from the light emitting portion.

The developing unit 30 is installed above the paper cassettes 11 and 11 'detachably from the frame 10 of the main body, and is emitted from the laser scanning unit (LSU) 76 according to the image signal. A phenomenon in which a toner image is developed by attaching toner to a photosensitive drum 32 that forms an electrostatic latent image by a beam, a charging roller (not shown) that charges the photosensitive drum 32, and an electrostatic latent image formed on the photosensitive drum 32. A roller (not shown), a cleaning blade (not shown) for cleaning the toner residue remaining on the surface of the photosensitive drum 32 after transferring the toner image onto the paper P, and a toner supply unit 34 for supplying the toner. It is provided.

In the panel 81 disposed to face the photosensitive drum 32 of the developing unit 30, a transfer roller 66 for transferring the toner image formed on the photosensitive drum 32 to paper P is provided.

The fixing unit 40 for pressing and fixing the toner image is composed of a fixing roller 41 disposed on the frame 10 of the main body and a fixing backup roller 42 disposed on the panel 81.

The discharge unit 50 for discharging the paper P on which the fixing of the image image is completed by the fixing unit 40 selectively installs the paper P which is installed at the end of the paper feed path A and is conveyed. A discharge direction guide member 54 rotating to guide, a plurality of discharge and backup rollers 60 ', 60 "; 64', 64" for discharging the paper P toward the paper discharge tray 67, and the paper P It consists of forward and reverse rotation and backup rollers (60, 64) are controlled to enable forward and reverse rotation according to the discharge direction of.

The double-sided printing unit 80 is installed to be opened and closed at the upper side of the discharge side of the main body 10 and is installed to open and close facing the outer surface of the panel 81 and the panel 81 on which the transfer roller 66 is supported. The cover frame 62 to form a paper conveying path B which is reversed by circulating the paper P on which one side printing is completed, and the paper conveying direction is moved so that the paper P moves to the paper conveying path B when duplex printing. First and second reverse feed rollers disposed on the panel 81 and the cover frame 62, respectively, for guiding the sheet feeding direction switching guide 89 and the sheet P to move through the sheet conveying path B; 70, 90 and first and second backup rollers 72, 92.

The paper feed direction switching guide 89 selectively restrains the paper P being conveyed on the paper discharge path of the discharge unit 50, thereby forming a paper conveying path B formed between the panel 81 and the cover frame 62. In order to guide by), the tip of the paper P has a shape capable of guiding the desired conveying direction.

Looking at the printing process of such a laser printer 1, as follows.

First, assuming that the paper P is fed from the paper feed cassette 11, the paper P of the paper feed cassette 11 is picked up by the pickup roller 7, and then the transfer and backup rollers 23 and 24 are carried out. By the sheet conveyance guide 22 toward the register roller 28.

At this time, the front end of the paper P pushes the sensor actuator of the paper sensing device 26 disposed in front of the register roller 28, so that the end of the sensor actuator rotates to be out of the paper sensing device 26. do. As a result, the light receiving portion of the device 26 receives the light transmitted from the light emitting portion, and sends a paper detection signal to the control portion.

The control unit counts the time at which the paper P moves from the paper sensing device 26 to the register roller 28 according to the paper detection signal, transfers the paper P for a predetermined time, and then registers the roller 28. Drive.

Therefore, at this time, the tip of the paper P conveyed to the register roller 28 is aligned while forming a curl for a predetermined time by a nip between the register roller 28 and the backup roller 29. After that, it is transferred to the developing unit 30.

At this time, the control unit counts the time that the paper P moves from the paper sensing device 26 to the transfer roller 66, so that the time taken for the paper P to reach the printing start position is set in advance. After the elapse of time, the developing unit 30 and the transfer roller 66 are operated.

While the paper P is being transferred to the developing unit 30, an electrostatic latent image is formed in the photosensitive drum 32 of the developing unit 30 by the laser beam emitted from the LSU 76 according to the image signal, and the photosensitive drum The electrostatic latent image developed at 32 is attached to a toner by a developing roller and developed into a toner image in the form of a visible image.

The toner image formed on the photosensitive drum 32 is one surface of the paper P by the transfer roller 66 when the paper P is transferred to the developing unit 30 along the paper feed path A, for example. For example, the toner image transferred onto the upper surface and transferred to the upper surface of the paper P is fixed to the upper surface of the paper P by the fixing roller 41 and the fixing backup roller 42 constituting the fixing unit 40. .

Thereafter, the paper P is conveyed toward the discharge direction guide member 54 located downstream of the paper feed direction of the fixing roller 41.

At this time, when the printer performs the single-sided printing mode, the paper P is guided toward the paper discharge stage 67 by the discharge direction guide member 54, and is discharged by the discharge rollers 60 ', 60 ". Is discharged to the zone 67.

However, when the duplex printing mode is performed, the paper P is guided toward the reverse rotation roller 60 and the backup roller 64 on the conveyance path of the discharge unit 50 by the discharge direction guide member 54.

In this case, when the rear end of the paper P passes the paper detection sensor 56, the reverse rotation roller 60 is controlled to be driven in reverse rotation, and as a result, the paper P is inverted and the paper discharge tray 67 Is transferred to).

When the paper P is conveyed toward the paper output tray 67 and the front end of the paper P operates the paper detection sensor 57, the paper feed direction switching guide 89 of the duplex printing unit 80 receives the paper P ) Is rotated to guide the paper conveying path (B).

In this way, the paper P entering the paper conveying path B is conveyed toward the second backfeed roller 90 by the first backfeed roller 70, and the paper is sensed by the second backfeed roller 90. It is conveyed to the developing unit 30 via the device 26 and the register roller 28, and the other side of the paper P, that is, the lower surface, is discharged to the external paper discharge bin 67 after the printing process as described above. do.

However, the conventional laser printer 1 has a paper sensor 26 for sensing the tip position of the paper P to align the leading edge of the paper and controlling the printing position of the paper, so that the paper When (P) is fed in a skew state, the time for which the leading edge of the paper (P) reaches the paper detection device (26) depends on the position where the paper detection device (26) is installed and the type or amount of paper skew. Will be different.

As such, when the time at which the leading end of the paper P reaches the paper sensing device 26 is changed, the time or timing at which the register roller 28 is driven by the paper sensing signal of the paper sensing device 26 is different. You lose. As a result, a difference in the amount of curl formed when the paper P stagnates in the nip between the register roller 28 and the backup roller 29 for front end alignment occurs.

That is, when the drive timing of the register roller 28 becomes slow and the amount of curl increases, a lot of noise or jams are likely to occur when the register roller 28 is driven, and conversely, the drive timing of the register roller 28 is reversed. If the amount of curl is reduced and the amount of curl decreases, the front end of the paper P may not be sufficiently aligned by the nip between the register roller 28 and the backup roller 29.

In addition, when calculating the driving timing of the photosensitive drum 32 of the developing unit 30 based on the sheet detection signal of the sheet detecting device 26, the printing position, i.e., the tip margin of the image printed on the sheet P is incorrect. It is controlled so as to cause a problem of poor print quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and the main object of the present invention is to accurately detect the leading position of the paper regardless of the skew type or amount of the paper, thereby leading to the edge alignment and leading margin of the paper to be printed. To provide a paper detection device of the office equipment that can effectively control the.

Another object of the present invention is to provide a paper sensing device of an office equipment having two sensor actuators to accurately detect the leading position of the paper.

1 is a schematic diagram of a conventional double-sided laser printer.

2 is a partial schematic view of a duplex laser printer to which a paper sensing device according to the present invention is applied;

3 is an exploded perspective view of a paper detection apparatus according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: frame 27: paper alignment unit

28: register roller 30: developing unit

32: photosensitive drum 40: fixing unit

70, 90: reverse feed roller 81: panel

100: paper detection device 112, 114: sensor actuator

120: sensor portion 122: light emitting portion

124: light receiving unit 130, 132: elastic spring

In order to achieve the above object, the present invention is to detect the leading edge of the paper used in the office equipment including a paper alignment unit for aligning the leading edge of the paper to control the leading edge alignment of the paper at least through the paper alignment unit A paper sensing device, comprising: at least two sensor actuators installed so as to be rotated by a paper when the paper is conveyed, and a paper sensing device for generating a paper sensing signal according to the rotation of the sensor actuator. To provide.

In a preferred embodiment, the sensor portion is disposed on the side of the paper conveying path so as not to disturb the movement of the paper, and the sensor actuator is disposed transversely on the paper conveying path so as to be operated by the leading edge of the paper.

At this time, it is preferable that the sensor actuators are arranged at predetermined intervals with respect to the horizontal direction of the paper so that the difference in the operation time of the sensor part does not occur over a certain range according to the skew form or the amount when the paper is transferred in the skew form.

The sensor unit includes at least one light sensor including a light emitting unit and a light receiving unit, and the sensor actuator includes at least one reflecting unit positioned on a side of the sensor unit to reflect light emitted from the light emitting unit to the light receiving unit.

It is preferable that the reflecting portion of the sensor actuator has a width in the paper conveying direction that is predetermined so that the sensor portion operates at an appropriate timing.

Hereinafter, the paper detection apparatus of the office equipment according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings and the description, the same components as in the prior art will be described with the same reference numerals.

2, a partial duplex laser printer to which a paper detection apparatus of an office apparatus according to the present invention is applied is partially shown.

The duplex laser printer aligns the leading end of the paper transferred from the loading cassette (not shown) for loading paper, the pickup / transport unit (not shown) for picking up and transferring the paper loaded in the loading cassette. And a developing unit (not shown) for forming a visible image on the paper conveyed by the paper alignment unit 27, and between the pickup / transfer unit and the paper alignment unit 27. And a paper sensing device 100 according to the present invention for sensing the leading edge of the paper to align the leading edge of the paper on which the image is to be formed and to control the printing position of the paper.

Components except for the sheet sensing device 100 of the present invention are the same as those of the conventional double-sided printing laser printer 1 described with reference to FIG. 1, and thus, detailed descriptions thereof will be omitted.

As shown in FIG. 3, the paper detecting apparatus 100 of the present invention is configured to rotate the paper P so that the paper P can be rotated by the paper P when the paper P is conveyed in the direction of the arrow along the paper feed path A. And first and second sensor actuators 112 and 114 installed in 10), and a sensor unit 120 for generating a paper detection signal in accordance with the rotation operation of the first and second sensor actuators 112 and 114.

The first and second sensor actuators 112 and 114 are supported by the actuators 112 and 114 at one end and the other ends of the elastic springs 130 and 132 so as to be operated by the paper P, respectively. It is arranged to be able to rotate to the frame 10 horizontally with respect to the paper feed path (A) by.

When the first and second sensor actuators 112 and 114 are disposed too far with respect to the horizontal direction of the paper P, for example, when they are disposed at positions corresponding to both edges of the horizontal direction of the paper P, When the paper P is conveyed in a skewed state, the deviation of the time during which the sensor unit 120 operates is the greatest, and the interval pre-selected in the horizontal direction of the paper P, for example, the paper, which can reduce the operating time deviation, for example, paper It is preferable to arrange | position so that one third of the width may be spaced apart.

The first and second sensor actuators 112 and 114 respectively form reflecting surfaces 112a and 114a on the surface located toward the sensor unit 120 so as to reflect light emitted from the sensor unit 120.

The width of the paper conveying direction of the reflecting surfaces 112a and 114a, that is, the operating range of the first and second actuators 112 and 114, is similar to the installation interval of the sensor actuators 112 and 114, and the operating time of the sensor unit 120. In this case, when the paper P is skewed, the operation of the sensor unit 120 and thus the driving of the register roller 28 are started too late or too early, so that the register roller 28 and the backup roller are started too soon. In the nip between 29, the paper P is appropriately set so that the paper P does not generate too much curl or too little curl.

The sensor unit 120 is disposed on the side of the paper feed path A so as to face the reflective surfaces 112a and 114a of the first and second sensor actuators 112 and 114 so as not to disturb the movement of the paper P. do.

The sensor unit 120 emits light and emits light, and light emitted from the light emitting unit 122 and reflected through the reflecting surfaces 112a and 114a of the first and second sensor actuators 112 and 114. It consists of an optical sensor comprising a light receiving unit 124 for detecting the.

Accordingly, the sensor unit 120 may be moved by two sheets of sensor actuators 112 and 114 even if one of the first and second sensor actuators 112 and 114 is pushed in the paper feed direction earlier than the other by the paper P. The sensor unit 120 generates a paper detection signal only when all are out of the operating range of the sensor unit 120, and if only one of the sensor unit 120 is out of the operating range of the sensor unit 120, the paper detection signal is not generated.

As described above, the paper detecting apparatus 100 of the present invention uses two sensor actuators 112 and 114 having a predetermined interval and an operating range to operate the sensor unit 120 at an optimized timing, thereby providing a paper P. Is transferred to the skew state, the noise due to the incorrect operation of the sensor 26 and the register roller 28 due to the installation position of the sensor or the skew form of the paper P, as in the conventional paper sensing device 26, or Jamming problems, insufficient paper edge alignment and leading margin control problems are avoided.

In the above, the paper sensing device 100 of the present invention has been described as being composed of one sensor 120 and two sensor actuators 112 and 114 each having one reflective surface, but more precise operation timing of the sensor unit. For the sake of clarity, the same principle as the embodiment described above may include one or more sensor units and two or more sensor actuators each having one or more reflecting surfaces or reflecting units.

The operation of the duplex laser printer 100 to which the paper sensing device of the office equipment of the present invention configured as described above is applied is almost similar to that of the duplex laser printer 1 shown in FIG. .

As described above, the paper sensing device of the present invention comprises two sensor actuators to accurately detect the line unit value of the paper regardless of the skew type or amount of paper, so that the edge alignment and the tip margin of the paper on which the image is to be printed. Can be effectively controlled.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and any person having ordinary skill in the art to which the present invention pertains without departing from the scope of the present invention as claimed in the claims may make various modifications and variations. Would be possible.

Claims (5)

A paper sensing device for sensing the leading edge of a paper used in an office equipment including a paper alignment unit for aligning the leading edge of paper, and controlling at least the leading edge alignment of the paper through the paper alignment unit. And at least two sensor actuators installed so as to be rotated by the paper when the paper is conveyed, and a sensor unit generating a paper detection signal according to the rotation of the sensor actuator. The method of claim 1, The sensor portion is disposed on the side of the paper feed path so as not to disturb the movement of the paper; The sensor actuator is a paper sensing device of the office equipment, characterized in that arranged on the paper transport path to operate by the paper. The method of claim 2, wherein the sensor actuators are arranged at predetermined intervals with respect to the horizontal direction of the paper so that the difference in the operating time of the sensor unit does not occur over a certain range according to the skew form when the paper is transferred in the skew form Paper detection equipment for office equipment. The method of claim 3, wherein The sensor unit includes at least one optical sensor including a light emitting unit and a light receiving unit; And the sensor actuator includes at least one reflector disposed on a surface of the sensor unit to reflect light emitted from the light emitter to the light receiver. 5. The apparatus of claim 4, wherein the reflecting portion of the sensor actuator has a width in a paper conveying direction that is selected so that the sensor portion operates at an appropriate timing.