KR100433419B1 - Paper decurling apparatus for image forming device - Google Patents

Abstract

Paper curling prevention device of the image forming apparatus according to the present invention, the image is installed in contact with the discharge roller rotatably installed in the discharge outlet printing the paper discharged through the discharge port along the paper transfer path of the image forming apparatus A longitudinal paper curl prevention roller for forming a predetermined paper ejection path so as to be bent in a direction opposite to the bending direction when conveyed, and a transverse direction provided in the discharge port to prevent the paper discharged out of the image forming apparatus from being warped in the horizontal direction; And a directional paper curl prevention roller. According to this, the sheet discharged to the outside of the image forming apparatus can be prevented from warping in the vertical direction and the horizontal direction.

Description

Paper curling apparatus for image forming apparatus {Paper decurling apparatus for image forming device}

The present invention relates to an image forming apparatus, and more particularly, to a paper curl prevention apparatus of an image forming apparatus which suppresses the discharge of the paper on which an image is printed to the outside of the image forming apparatus through a discharge port.

In general, an image forming apparatus such as a laser beam printer, a copying machine, a multifunction printer, or the like is a device for printing a predetermined image on printing paper through an electrophotographic developing process, as shown in FIG. And a developing apparatus 120 for printing a predetermined image corresponding to the input image data using a developer on the paper feeder 110 provided outside and the paper S supplied through the paper feeder 110. ), A fixing apparatus 130 for pressing the paper S on which the image is printed to a high temperature to fix the developer to the paper S, and a discharge port 140 through which the printed paper S is discharged. It includes a discharge roller 153 is installed, and a paper feed path (P) for guiding the paper (S) to be transferred from the paper feed device 110 to the discharge port 140. Reference numeral 155 is a backup roller installed in contact with the discharge roller 153 so as to interlock rotationally driven when the discharge roller 153 rotates.

The paper feed path P is formed to guide the paper S along various curves from the paper feeder 110 to the discharge port 140 due to the design limitation of the image forming apparatus. In particular, a part of the paper conveyance path P corresponding to the discharge port 140 from the developing apparatus 120 is typically formed in a curved shape that is bent in one direction.

In the conventional image forming apparatus configured as described above, the paper S, which has been hot-pressed, in the fixing step by the fixing device 130 is conveyed along the paper conveying path curved in a predetermined direction. As a result, as shown in FIG. 2, the paper S discharged through the discharge port 140 is discharged in the longitudinal direction, that is, in a state of being folded toward the bottom surface S1 where image printing is not performed. The curling phenomenon of the paper S is generated not only in the longitudinal direction of the paper S but also in the horizontal direction, so that the paper S is conveyed in a state in which a wave is formed throughout. Accordingly, when a plurality of sheets S printed on the sheet stacker 160 are stacked, jams are frequently generated in the discharge port 140 due to interference between the curled sheets S. Problems arise such as the formation of wrinkles (W) in the longitudinal direction of the paper (P) discharged by the wave formed in the transverse direction.

In order to solve this problem, conventionally, a method such as lowering the fixing temperature, increasing the discharge path, and curling the paper on the paper feed path (P) to form a part of the paper feed path (P) to be bent in a predetermined direction. A method of separately installing a prevention device (not shown) was used. However, there is a problem that the size of the image forming apparatus is increased or the printing speed is decreased when using this method, and the paper curling prevention device that is commonly used can suppress the curling of the paper S that is bent in the longitudinal direction. It was not possible to suppress the lateral curl of the paper which is bent along the horizontal direction of the paper S.

In particular, in recent years, the paper S tends to increase the size of the fixing roller 135 so that the paper S may be in contact with the fixing device 130 in a short time. This can happen more easily, and a more effective paper curl prevention device is required.

The present invention has been made to solve the above problems, to provide a paper curl prevention apparatus of the image forming apparatus that can suppress the vertical and horizontal curl phenomenon generated in the paper discharged to the outside of the image forming apparatus. There is this.

1 is a cross-sectional view showing a conventional image forming apparatus;

FIG. 2 is a perspective view illustrating a state of paper discharged through the discharge port of the image forming apparatus of FIG. 1; FIG.

3 is a perspective view showing a paper curl prevention apparatus of an image forming apparatus according to an embodiment of the present invention;

4 is a perspective view showing an example of use of the paper curl prevention device of FIG.

Explanation of symbols on the main parts of the drawings

100: image forming apparatus main body 110: paper feed apparatus

120: developing device 130: fixing device

140: discharge port 151: rotation drive shaft

153: output roller 156: first sheet curl prevention roller

157: second paper curl prevention roller 159: third paper curl prevention roller

160: paper stacker

An image forming apparatus according to the present invention for achieving the above object is a discharge port for discharging the paper on which the image is printed, a rotary drive shaft installed in the discharge port and rotationally driven, a plurality of the paper is disposed on the rotary drive shaft And a discharge roller and a paper curl prevention device which are rotated to be in contact with the paper entered into the discharge port so as to discharge the discharge to the outside through the discharge port. The paper curl prevention device is provided to contact the discharge roller so that the paper discharged through the discharge port bends a predetermined paper discharge path so as to be bent in a direction opposite to the bending direction during the transfer along the paper transfer path of the image forming apparatus. A longitudinal paper curl prevention roller to be formed; And a transverse paper curl prevention device installed in the discharge port to prevent the paper discharged to the outside of the image forming apparatus from being bent in the horizontal direction.

According to this, the phenomenon of warping in the longitudinal direction and the horizontal direction of the paper discharged through the discharge port can be effectively suppressed, thereby preventing jams occurring on the discharge port side of the image forming apparatus and at the same time in the longitudinal direction of the paper. It can suppress that wrinkles generate | occur | produce.

According to a preferred embodiment of the present invention, the longitudinal paper curl prevention roller is installed in contact with the discharge roller on the front and rear sides of the discharge roller along the conveying direction of the paper in accordance with the rotational drive of the discharge roller It is preferable to include a first and second paper curl prevention roller for forming the paper discharge path for forcibly conveying the paper along the portion in contact with the discharge roller by the interlocking rotation drive.

The transverse paper curl prevention apparatus further includes a plurality of third curl curl prevention rollers installed on the rotation drive shaft and disposed between the discharge rollers.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Meanwhile, the components having the same configuration as those of the conventional image forming apparatus shown in FIG. 1 and performing the same functions are denoted by the same reference numerals, and detailed description thereof will be omitted.

Referring to FIG. 3, the image forming apparatus according to the embodiment of the present invention has a rotational drive shaft 151 provided on the discharge port 140 (refer to FIG. 1) and a predetermined distance therebetween on the rotation drive shaft 151. And a plurality of discharge rollers 153 installed in a plurality, and the discharge rollers 153 are rotationally driven when the discharge rollers 153 come into contact with the paper S (see FIG. 1) entering the discharge port 140, thereby discharging the paper S. It is forcibly pushed out in the direction of the earth 140 and discharged to the paper stacker 160 (see FIG. 1). The discharge port 140 is provided with a longitudinal paper curl prevention roller and a horizontal paper curl prevention apparatus as a paper curl prevention device.

As shown in FIG. 4, the longitudinal paper curl prevention roller is conveyed along the paper feed path P (see FIG. 1) while the paper S compressed at high temperature through the fixing device 130 (see FIG. 1). It is for suppressing curvature in the longitudinal direction, and includes a first sheet curling prevention roller 156 and a second sheet curling prevention roller 157.

The first paper curl prevention roller 156 is free to rotate the rotation axis as the center of rotation on the first fixing bracket 156a installed on the front side of the delivery roller 153 along the feed direction A of the paper S. This is possibly installed. The second sheet curling prevention roller 157 is freely rotatable with its rotation axis as the center of rotation on the second fixing bracket 157a provided on the rear side of the delivery roller 153 along the conveying direction of the paper S. FIG. Is installed.

Here, the first and second paper curl prevention rollers (156, 157) are installed to correspond to each of the discharge roller 153 is installed on the rotary drive shaft 151 in a plurality, a portion of the outer peripheral surface of the discharge roller ( It is installed to be always in contact with the outer peripheral portion of the 153, it is installed to rotate in conjunction with the discharge roller 153 during the rotation drive of the discharge roller 153. The first and second sheet curling prevention rollers 156 and 157 also function as backup rollers.

With this configuration, the paper discharge path a formed so as to pass through the contact surface between the discharge roller 153 and each of the paper curl prevention rollers 156 and 157 has the same shape as the curve of the outer circumferential surface of the discharge roller 153. Is formed. The paper discharge path (a) is connected to the paper feed path (P) connecting the fixing device 130 and the discharge port 140, wherein the paper discharge path (P) has a phase opposite to the curve of the paper feed path (P) of the section It is formed to form a curve. That is, when the section of the paper transport path (P) connecting the fixing device 130 and the discharge port 140 guides the paper (S) in a curved direction formed so that the printing surface side of the paper (S) is convexly curved. The paper discharge path (a) is formed along the lower outer circumferential surface of the discharge roller 153 so that the opposite side surface S1 (see FIG. 2) on which the image is not printed is convexly curved. Accordingly, the paper entering the discharge port 140 in a state where the tip is bent toward the surface S1 where the image is not printed while being compressed along the high temperature through the fixing device 130 and then transported along the paper feed path P ( S) is a paper (S) is guided so that the leading edge of the paper (S) is bent toward the surface on which the image is printed by the first and second paper curl prevention rollers (156, 157) and the discharge roller (153) Longitudinal curl of (S) can be suppressed.

The transverse paper curl prevention apparatus is conveyed in a state in which a wave is formed at the front end of the paper S along the horizontal direction of the paper S, as shown in FIG. 2, in the longitudinal direction of the paper S. To prevent wrinkles. In order to perform this function, the transverse paper curl prevention device includes a third paper curl prevention roller 159 installed on the rotary drive shaft 151 in plurality.

The third sheet curling prevention roller 159 is installed between each of the discharge rollers 153 so as not to be in contact with the discharge roller 153 when the paper S is transferred along the paper discharge path a. Press the rest of S) in the paper discharge path (a). According to this, the third paper curling prevention roller 159 presses a portion which is convex upward in the paper S by not coming into contact with the delivery roller 153, thereby causing wrinkles or the like in the longitudinal direction of the paper S. Can be suppressed. At this time, unlike the discharge roller 153, the third sheet curling prevention roller 159 may be excluded from the installation of the backup roller 155 (see Fig. 1) in contact with the outer peripheral surface thereof.

The paper curl prevention apparatus of the image forming apparatus configured as described above may be variously modified according to the paper feed path of the image forming apparatus. For example, when the paper feed path P is formed to be bent in a direction opposite to that of the present embodiment, the first and second paper curl prevention rollers 156 and 157 are in contact with the upper outer peripheral surface of the discharge roller 153. It is possible to apply in various forms, such as to be installed so that the curved paper (S) can be discharged in a flat state.

According to the present invention constituted as described above, a plurality of lateral paper curl prevention rollers are formed between the longitudinal paper curl prevention rollers which are driven to each of the discharge rollers on the discharge port side of the image forming apparatus, and each of the discharge rollers on the rotation drive shaft of the discharge rollers. It includes a roller.

As a result, it is possible to effectively suppress the warpage in the longitudinal direction and the transverse direction of the paper, to prevent jams occurring on the discharge port side of the image forming apparatus, and to suppress the paper from being discharged in the lengthwise direction. can do.

While the invention has been shown and described with respect to preferred embodiments for illustrating the principles of the invention, the invention is not limited to the construction and operation as shown and described. Rather, those skilled in the art will appreciate that various changes and modifications can be made to the present invention without departing from the spirit and scope of the appended claims. Accordingly, all such suitable changes, modifications, and equivalents should be considered to be within the scope of the present invention.

Claims (3)

A discharge port for discharging the paper on which the image has been printed, a rotation drive shaft installed at the discharge port and rotationally driven, and a plurality of discharge outlets disposed on the rotation drive shaft to discharge the paper to the outside through the discharge port. In the paper curling prevention device of the image forming apparatus comprising a discharge roller which is rotated in contact with the paper entered into the Longitudinal paper curl which is installed in contact with the discharge roller and forms a predetermined paper discharge path so that the paper discharged through the discharge port is bent in a direction opposite to the bending direction when the paper discharged through the paper feed path of the image forming apparatus is conveyed. Anti-roller; And And a transverse paper curl prevention device installed in the discharge port to prevent the paper discharged to the outside of the image forming device from being warped in the horizontal direction. The method of claim 1, wherein the longitudinal paper curl prevention roller, It is installed in front and rear sides of the discharge roller along the conveying direction of the paper to be in contact with the discharge roller is driven in accordance with the rotation drive of the discharge roller to force the paper along the portion in contact with the discharge roller And a first and second paper curl prevention rollers for forming the paper discharge path to be conveyed. According to claim 1, wherein the transverse direction paper curl prevention device, And a plurality of third paper curl prevention rollers installed on the rotation driving shaft to be disposed between the discharge rollers, respectively.