KR20140084649A - Apparatus for printing image on a paper - Google Patents

Abstract

A document output apparatus according to an embodiment of the present invention includes: a paper feed cassette for supplying printing paper; An image forming unit for forming an image on a printing paper supplied from the paper feed cassette; A discharging unit for discharging the printing paper having passed through the image forming unit to the outside; A first roller portion for feeding the printing paper fed from the paper feed cassette; A second roller portion positioned in front of the first roller portion and guiding the printing paper conveyed from the first roller portion to the image forming portion; A stopper disposed between the first roller portion and the second roller portion to eliminate a skew state of the printing paper passing through the first roller portion; And a driving member connected to the stopper to allow the stopper to move up and down.

Description

[0001] Apparatus for printing image on a paper [0002]

The present invention relates to a document output apparatus including a printer.

The document output device is a device coupled to a host device including a computer and outputs image data transmitted from the host device to a print medium including paper in accordance with a print signal applied from the host device. Such a document output apparatus includes a print medium supply unit for supplying a print medium, an image forming unit for forming an image on the print medium, and a discharge unit for discharging the print medium on which the image is formed.

In detail, the print medium supply unit includes a paper feed cassette on which a print medium, that is, print paper, is loaded, a friction pad provided on the upper surface of the paper feed cassette, and a pickup roller in contact with the friction pad. A front end portion of the printing paper is interposed between the friction pad and the pick-up roller, and the printing paper is transferred by the rotation of the pick-up roller.

In recent years, the demand for printing on various types of paper has been increasing. Therefore, in addition to ordinary paper, there is a very wide demand ranging from very thin paper such as thin paper or card stock paper to coated paper, label paper and oil paper .

Such a conventional document output apparatus has a skew problem in which the paper is turned to the left or right on the moving line when the printing paper is conveyed to the image forming unit. The skew phenomenon occurs due to various causes, which may occur when picking up a print sheet from a pick-up roller, or occurring when the sheet slips on one of the left and right conveying rollers in the process of being conveyed by the conveying roller. In this case, there arises a problem that the print contents can not be accurately printed on the printing paper.

Korean Unexamined Patent Publication No. 2011-0064076 or No. 2011-0040471 discloses a method of correcting a print image instead of correcting the inclination of a sheet upon detecting a skew. In the case of the 2008-0035899, when skew occurs, And adjusting the feeding force to solve the skew problem.

In a conventional general document output apparatus, when the skew occurs, the printing operation is stopped or the rotational speed of some of the rollers connected to a single axis is changed to solve the skew problem. However, these solutions do not fundamentally block the skew problem and still do not solve the print quality degradation problem.

The document output apparatus according to an embodiment of the present invention has been proposed in order to solve the problems described above. Even if the paper is fed in the process of being fed by the pick-up roller or the feed roller, skew correction is performed in front of the image forming section And then transferred to the image forming section.

According to another aspect of the present invention, there is provided a document output apparatus including: a paper feed cassette for supplying printing paper; An image forming unit for forming an image on a printing paper supplied from the paper feed cassette; A discharging unit for discharging the printing paper having passed through the image forming unit to the outside; A first roller portion for feeding the printing paper fed from the paper feed cassette; A second roller portion positioned in front of the first roller portion and guiding the printing paper conveyed from the first roller portion to the image forming portion; A stopper disposed between the first roller portion and the second roller portion to eliminate a skew state of the printing paper passing through the first roller portion; And a driving member connected to the stopper to allow the stopper to move up and down.

According to the document output apparatus according to the embodiment of the present invention configured as described above, even if a skew occurs in the sheet conveying process, the sheet is deskewed to the normal position before entering the image forming unit, There is an effect that can be printed on.

Also, there is an advantage that a jam prevention effect due to skew can be expected through a deskew process.

1 is a perspective view showing a configuration of a document output apparatus provided with a paper aligning unit according to an embodiment of the present invention;
2 is a view showing a print paper feed path of a document output apparatus according to an embodiment of the present invention.
3 is a perspective view showing a skew prevention structure according to an embodiment of the present invention;
4 is a diagram showing a state in which a skew prevention function is performed;
5 is a diagram showing a state after the skew prevention function is completed;

Hereinafter, a document output apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 is a perspective view showing a configuration of a document output apparatus according to an embodiment of the present invention.

1, a document output apparatus 10 according to an embodiment of the present invention includes a paper feed cassette 11 for storing a print medium, that is, a print paper, An ink supply unit 21 for supplying a printing material containing ink to the image forming unit 18 and an ink supply unit 21 for supplying a printing paper stored in the paper feeding cassette 11 to the image forming unit 18, And a discharge roller unit for discharging the sheet on which the image is formed while passing through the image forming unit 18. [

In detail, the conveying roller unit includes a first pick-up roller 31 positioned at the top of the front face of the paper feed cassette 11 to pick up the print sheets one by one, and a second pick-up roller 31 which picks up the print paper picked up by the first pick- An acceleration roller 32 for transferring the printing paper conveyed from the acceleration roller 32 to the image forming unit 18 at a speed corresponding to the printing speed, (34). The printing paper conveyed from the acceleration roller 32 is guided to the conveying roller 34 by the paper feeding guide 12 safely. The printing paper is guided safely to the image forming unit 18 by the guide plate 17 connected to the end of the paper feeding guide 12.

The discharge roller unit includes a vertical roller 37 and a discharge roller 38 for discharging the printing paper passed through the image forming unit 18 to the outside. A pair of idle rollers can be brought into contact with each other in the direction in which they oppose each other on the outer circumferential surface of the sheet discharge roller (38). And, the pair of idler rollers includes a delivery idle roller 381 and a switching idle roller 382, the functions of which are described in more detail below. In addition to the above-mentioned rollers, a plurality of rollers for transferring printing paper will be described in more detail with reference to the drawings below.

The delivery unit includes a delivery guide 19 for guiding the print sheet guided by the vertical roller 37 to be accurately guided to the delivery roller unit, And a guide guide 20 for guiding the guide member 20 accurately.

The image forming unit 18 may be an inkjet head having nozzles for ejecting ink having different colors at a high speed. The inkjet head may include a PSA Page Straight Array) head or a PWP (Page Width Printer) head. However, the present invention is not limited to this, and a shuttle-typed head that reciprocates left and right with the ink cartridge mounted is also possible. Further, it is needless to say that the image forming unit 18 may be a transfer type head for jetting toner.

The document output apparatus 10 includes a main motor 13 for providing a rotational force to the conveying roller unit, a gear assembly for transmitting rotational force generated by the main motor 13 to a plurality of conveying roller shafts, (14). The rotational force supplied from the single drive source by the gear assembly 14 allows a plurality of rotational shafts to be simultaneously rotated.

The document outputting apparatus 10 further includes a feed motor 15 for providing a rotating force to the paper discharge roller unit and a duplexer 15 for providing a rotational force to an inversion roller unit (to be described later) A motor (Duplex motor) 16 may be further included.

The printing process of the document output apparatus 10 according to the embodiment of the present invention will be briefly described. The printing paper loaded on the paper feed cassette 11 is conveyed to the image forming unit 18, and the printing paper on which the image is printed on one side while passing through the image forming portion 18 is discharged to the outside of the output device through the discharge roller portion and the discharge portion.

Hereinafter, the conveyance path of the printing paper loaded in the paper feed cassette 11 will be described in detail with reference to the drawings.

2 is a view showing a print paper feed path of the document output apparatus according to the embodiment of the present invention.

2, the document output apparatus 10 according to the embodiment of the present invention may be printed using the printing paper loaded in the paper feed cassette 11 or may be a multi-purpose tray or a manual tray Manual Paper Tray). The document output apparatus 10 includes a first pickup roller 31 provided at an upper front of the paper feed cassette 11 and a second pickup roller 33 provided at a front end of the multipurpose tray or the manual tray, . ≪ / RTI >

In detail, on the front side of the first and second pick-up rollers 31 and 32, a conveying roller 34 for conveying the printing paper to the image forming unit 18 is provided. An acceleration roller 32 is provided between the conveying roller 34 and the first pick-up roller 31 to receive the print paper picked up by the first pick-up roller 31, . That is, the linear velocity of the acceleration roller 32 is set to be faster than the linear velocity of the first pick-up roller 31. Here, when the linear velocity of the first pick-up roller 31 is set to be close to the linear velocity of the acceleration roller 32, the printing paper may not be picked up and the idling may occur. Therefore, it is general to set the linear velocity of the first pickup roller 31 to be smaller than the linear velocity of the acceleration roller 32. Since there is a difference in height between the first pick-up roller 31 and the feed roller 34, the leading end of the picked-up print paper is stably held on the feed roller 34 by the pickup roller 31 The acceleration roller 32 is provided for this purpose. The linear velocity of the rollers provided after the acceleration roller 32 may be set to be equal to the linear velocity of the acceleration roller 32. The conveying roller 34 may be disposed at a plurality of points according to the specification of the product.

On the other hand, a drawing roller 35 may be installed in front of the conveying roller 34. The drawing roller 35 is also referred to as a feed roller. The drawing roller 35 is located in a room immediately below the image forming section 18 (with reference to the printing direction of the paper), so that the printing paper can be stably guided to the image forming section 18. According to the product, a skew prevention structure may be provided in a room immediately after the pull-in roller 35 in order to prevent a skew phenomenon of the printing paper. Alternatively, the rotation speed of the pulling-in roller 35 may be controlled so that the fed-in printing paper is returned to the normal position.

A discharge roller 36 is provided in front of the image forming portion 18 so that the printing paper on which an image is formed while passing through the image forming portion 18 is moved out of the image forming portion 18. [ A vertical roller 37 is provided in front of the discharge roller 36 to guide the print sheet out of the image forming portion 18 to the discharge roller 38. [ A paper idler roller 381 is provided on one side of the outer circumferential surface of the paper feed roller 38. Thus, the printed printing paper passes between the paper discharge roller 38 and the paper idle roller 381, and is discharged onto the loading surface 101 on which the printed paper is loaded.

On the other hand, in the case of the document output apparatus 10 provided with the double-side copying function, the reversing idle roller 382 is provided on the other side of the outer periphery of the paper discharge roller 38. Then, the printing paper having been printed passes through between the paper discharge roller 38 and the reversing idle roller 382. That is, the paper discharge roller 38 can perform the paper discharging function and the paper reversing function at the same time. Specifically, before the printing paper is completely released from the discharge roller 38 and the reversing idle roller 382, the discharge roller 38 pauses and then rotates reversely, thereby reversely transferring the printing paper to the reverse path.

A path denoted by A in the drawing can be defined as a print path, and a path denoted by B can be defined as an inversion path. The print path A may include a paper feed path, a print path, and a paper path. The reversal path B reverses the printing paper printed on only one side so that the other side that is not printed is guided to the printing path in a state of facing the image forming unit 18. [ A plurality of conveying rollers 39, 40 and 41 may be spaced apart from each other by a predetermined distance on the reversing path B.

Here, the pickup rollers 31 and 33 and the acceleration roller 32 may be defined as a feeding roller unit, and the feeding roller 34 and the feeding roller may be defined as a feeding roller unit. The discharge roller 36, the vertical roller 37 and the discharge roller 38 can be defined as discharge roller portions. The feed rollers 30, 40 and 41 provided on the inversion path may be defined as reversing roller units. Each of the rollers constituting the roller portion is provided with a driving roller rotated by a rotational force transmitted from a motor and an idler roller contacting with the driving roller in one unit or a set. The idle roller is a roller that rotates by a moment generated by a frictional force with the printing paper when the printing paper passes.

The rollers bundled with the dashed line M1 can receive the rotational force from the main motor 13 through the gear assembly 14 and the rollers bundled with the dashed line M2 can receive the rotational force from the feed motor 15. [ The rollers bundled with the dotted line M3 can receive the rotational force from the duplex motor 16 through the gear assembly. However, the present invention is not limited to the above-described embodiment, and the paper feeding and conveying roller unit may receive rotational force from the main motor 13, and the paper ejecting roller unit may be designed to receive rotational force from the paper ejecting motor 15. [ That is, the discharge roller 36 and the vertical roller 37 may be designed to receive the rotational force from any one of the main motor 13 and the sheet discharge motor 15.

3 is a perspective view illustrating a skew prevention structure according to an embodiment of the present invention.

Referring to FIG. 3, the skew prevention structure according to the embodiment of the present invention includes a conveying roller 34 at which the leading end of the printing paper is correctly or obliquely drawn, And a drawing roller (35) for transferring the printing paper correctly aligned by the desk element to the image forming portion.

In detail, the desk element does not necessarily have to be between the conveying roller 34 and the drawing roller 35. That is, it may be installed at any point between adjacent rollers among the rollers between the pick-up rollers 31, 33 and the pull-in roller 35. Therefore, in the sense of limiting to the roller member representing these rollers, the conveying roller 34 can be defined as a first roller portion, and the drawing roller 35 can be defined as a second roller portion, The desqueue member is provided between the roller 34 and the drawing roller 35 as one embodiment.

More specifically, the conveying roller 34 includes a rotation shaft 343 that receives rotation force from the motor and rotates, a driving roller 341 connected to the rotation shaft 343, and an idler roller 342 that contacts the driving roller 341. (342). The idle roller 342 rotates by a frictional force with the driving roller 341 or rotates by a frictional force with the printing paper when the printing paper passes.

The desqueering member is a stopper 50 for correctly aligning the leading end of the printing paper passing through the conveying roller 34 and is moved up and down by the driving member 60 in front of the conveying roller 34. The stopper 50 may be formed in a direction perpendicular to the conveying direction of the printing paper so that the leading end of the printing paper is struck. The driving member includes a solenoid 60 that controls the direction of current to move the stopper 50 in the vertical direction.

Hereinafter, the operation of the skew prevention structure will be described in detail with reference to the drawings.

FIG. 4 is a diagram showing a state in which the skew prevention function is performed, and FIG. 5 is a diagram showing a state after the skew prevention function is completed.

4, the printing paper picked up by the pick-up rollers 31 and 33 is conveyed toward the image forming unit 18 along the guide plate 70. As shown in FIG. Here, power is applied to the solenoid 60 along with the pickup operation of the printing paper or sequentially, and the stopper 50 is raised by the operation of the solenoid 60. Of course, the guide plate 70 may be formed with a hole through which the stopper 50 can pass. As the stopper 50 moves upward, the conveyance path of the printing paper is blocked.

In detail, the printing paper picked up by the pick-up rollers 31 and 33 can be conveyed at an angle while being guided to the first roller portion, i.e., the conveying roller 34, . Then, one side of the leading end of the printing paper can be drawn into the conveying roller 34 before the other side. Then, the sheet is guided forward in an oblique state by a nip pressure between the driving roller 341 and the idle roller 342 constituting the conveying roller 34.

Then, one end of the leading end of the printing paper first strikes the stopper 50, and the other end strikes the stopper 50 thereafter. The stopper 50 is lifted for a predetermined period of time and is lowered by the operation of the solenoid 60 so that the printing paper is transported toward the second roller portion, that is, the drawing roller 35. Here, the rising time of the stopper 50 may be set as follows.

First, when the number of rotations of the driving roller 341 constituting the conveying roller 34 reaches the set rotation speed, the stopper 50 can be lowered. When the distance between the conveying roller 34 and the stopper 50 is determined when the printing paper is normally fed into the conveying roller 34 and the distance between the conveying roller 34 and the stopper 50 is determined, The number of revolutions of the driving roller 341 will be calculated. Then, the time taken for the printing paper to move by the distance based on the feeding speed of the printing paper will be calculated. The time taken for the entire leading edge of the printing paper to hit the stopper 50 will be calculated using the number of revolutions and the moving time as variables. Therefore, as shown in FIG. 5, the stopper 50 can be quickly lowered as the time calculated from the point in time when the printing paper is drawn into the conveying roller 34 elapses. Then, the printing paper can be quickly guided to the image forming unit 18 by minimizing the time during which the printing paper stops during transportation. When the time for which the printing paper stops is long, the leading edge of the printing paper on the side of the stopper 50 that is struck first may be pushed by the linear pressure of the conveying roller 34 and may be wrinkled. If the printing paper is wrinkled, the possibility of jamming increases. Therefore, it is necessary to precisely set the holding time of the rising state of the stopper (50).

Second, it is also possible to attach the sensor to one surface of the stopper 50, that is, the surface where the leading end of the printing paper hits.

In detail, a sensor capable of detecting the collision of the printing paper is attached to the left and right sides of the stopper 50, and the sensors may be arranged to be equal to the width of the printing paper or spaced apart from the width of the printing paper have. This is because, if the interval between the sensors is larger than the width of the printing paper, the left and right ends of the printing paper can not be detected.

As soon as the pair of sensors sense the collision of the printing paper, the stopper 50 is quickly lowered, and the printing paper can be conveyed to the drawing roller 35 as soon as the printing paper is properly aligned.

It is to be noted that the driving member for moving the stopper 50 in the vertical direction is not limited to the solenoid 60 shown. For example, the gear assembly and the driving motor may be mounted on the side of the stopper 50 so that the upward and downward movement of the stopper 50 may be controlled by the rotation of the gear. Therefore, all the driving means capable of moving the stopper 50 up and down can be applied.

Claims (6)

A paper feed cassette for supplying print paper;
An image forming unit for forming an image on a printing paper supplied from the paper feed cassette;
A discharging unit for discharging the printing paper having passed through the image forming unit to the outside;
A first roller portion for feeding the printing paper fed from the paper feed cassette;
A second roller portion positioned in front of the first roller portion and guiding the printing paper conveyed from the first roller portion to the image forming portion;
A stopper disposed between the first roller portion and the second roller portion to eliminate a skew state of the printing paper passing through the first roller portion; And
And a driving member connected to the stopper to allow the stopper to move up and down. The method according to claim 1,
Wherein the stopper has a vertical surface on which the leading end of the printing paper contacts. 3. The method of claim 2,
Wherein the driving member includes a solenoid. 3. The method of claim 2,
When the paper feed is started, the stopper is in an elevated state,
Wherein the stopper is lowered when both ends of the leading end of the printing paper come into contact with the stopper. 3. The method of claim 2,
And a sensor mounted on the vertical surface to detect contact of the printing paper. 6. The method of claim 5,
The sensor is mounted on the left and right sides of the vertical plane, respectively,
Wherein a distance between the sensors is equal to or smaller than a width of the printing paper.

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