KR100701323B1 - Paper feeding apparatus for image forming apparatus - Google Patents

Abstract

A paper feeding device for an image forming apparatus is provided to perfectly arrange front ends of papers all the time irrespective of the thickness of the used papers with the improved structure of the paper feeding device. The first and the second feeding roller assemblies(110,120) are rotatably installed on a paper feeding path(C). At least one or more tension idle wheels(200) are installed in one of the first and the second feeding roller assemblies(110,120). When the first and the second feeding roller assemblies(110,120) closely adhere each other, the tension idle wheels(200) are elastically modified in a radius direction. A paper front end arranging member(300), installed on the first and the second feeding roller assemblies(110,120), arranges front ends of fed papers.

Description

Paper feeding apparatus for image forming apparatus

1 is a view schematically showing a configuration of a general image forming apparatus;

FIG. 2 is a perspective view of main parts of a paper conveying apparatus employed in the image forming apparatus of FIG. 1; FIG.

3 is a side view of a paper conveying apparatus of the image forming apparatus according to an embodiment of the present invention;

4 is a front view of FIG. 3;

5 is a perspective view of a feed roller assembly of a paper conveying apparatus according to an embodiment of the present invention;

6 is a perspective view of a tension idle wheel provided in the feed roller assembly of FIG.

7A and 7B are views for explaining the paper leading alignment action of the paper feed apparatus of the present invention;

Figure 8 is a side view showing a state in which the conveying roller assembly is rotated in the state of Figure 3,

9 is a front view of FIG. 8.

<Description of Symbols for Main Parts of Drawings>

110; A first feed roller assembly 111; First axis of rotation

112; First feed roller 120; Second feed roller assembly

121; Second rotating shaft 122; 2nd feed roller

200; Tension idle wheel 210; paddle

220; Inner ring 230; Wheel

300; Paper leading alignment member 310; Breaking

320; Actuator 330; Hinge

400; Sensing unit 500; Drive unit

510; Cam member 520; motor

The present invention relates to an image forming apparatus, and more particularly, to a paper conveying apparatus of an image forming apparatus.

In the general image forming apparatus, as shown in FIG. 1, the paper P accommodated in the paper feeding unit 1 is picked up by the pickup unit 2 and enters the transfer unit 10. Paper entering the transfer unit 10 is formed with a predetermined image on its surface via the developing unit 3 and the transfer unit 4. The paper on which the image is formed is fixed while passing through the fixing unit 5, and is discharged to the outside through the discharge unit 6.

On the other hand, the transfer unit 10 is provided with a paper leading edge alignment device to align the leading edge of the picked-up paper in a straight line. 2 shows an example of an iso unit 10 equipped with such a paper leading end alignment device.

As shown in FIG. 2, the transfer unit 10 is spaced apart from the plurality of first feeding rollers 13 and the drive shaft 12 provided at predetermined intervals on the drive shaft 12 to which the motor 11 is connected. The second feed roller 15 is provided on the idle rotation axis 14 to correspond to the first feeding roller 13, and a paper leading alignment shutter 16 for aligning the leading edge of the entered paper.

The paper tip alignment shutter 16 is installed under the elastic member so as to open the paper feed path while rotating in the direction of the arrow shown by the paper feed force when the leading edge of the paper P is aligned in a straight line. According to this configuration, the paper entering the conveying unit 10 is conveyed to the developing unit 3 side with its tip aligned.

However, the paper conveying apparatus of the general image forming apparatus as described above, when the thickness of the paper is thick or the inertial force of the picked-up paper is larger than the elasticity of the elastic member that elastically supports the paper leading alignment shutter 16, the leading edge of the paper In this unaligned state, the paper leading alignment shutter 16 can be rotated to open the paper feed path. In this case, since the paper to be conveyed enters the developing unit 3 in a misaligned state, there is a problem that a printing error occurs such as an image being misaligned and printed on the paper.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object thereof is to provide a paper conveying apparatus of an image forming apparatus in which the structure is improved so that the leading edge alignment of a sheet is always performed regardless of the thickness of the sheet to be used.

The paper conveying apparatus of the image forming apparatus according to the present invention for achieving the above object, the first and second feed roller assembly rotatably installed in the paper conveying path; At least one tension idle wheel installed in any one of the transfer roller assemblies, wherein the at least one tension idle wheel is elastically deformed in a radial direction when the first and second transfer roller assemblies are in close contact with each other; And a paper leading end alignment member installed at a rear side of the first and second transfer roller assemblies to align the leading ends of the transferred paper.

According to a preferred embodiment of the present invention, the tension idle wheel slip conveys the conveyed paper when the first and second conveying roller assemblies are spaced apart, and includes a plurality of sensors for detecting whether the paper is aligned with the front end. Sensing unit; And a driving unit which drives the paper leading alignment member to rotate and close the first and second feed roller assemblies so as to open the paper feed path when the paper leading alignment signal is detected by the sensing unit. .

The second feed roller assembly, a plurality of rollers; And a flexible rotating shaft rotatably supporting the roller and elastically deformed with respect to an external force.

The tension idle wheel is preferably installed to be idling the second feed roller assembly.

Such tension idle wheel may include: an outer ring in contact with the first feed roller assembly; An inner ring into which the rotating shaft of the second feed roller assembly is fitted; And a plurality of wheels connecting the outer ring and the inner ring and bent at a predetermined angle in a radial direction. Two to five wheels are suitable, and the plurality of wheels are bent in the same direction.

In addition, it is preferable that the tension idle wheel is integrally formed of resin, and the outer ring preferably has an outer surface smoothly processed to generate slip with paper.

In addition, the flexible rotation shaft is preferably composed of an optical fiber that also serves as a signal transmission path of the sensor.

On the other hand, the paper leading edge alignment member has a blocking portion located in the paper feed path and an operating portion connected vertically from the blocking portion; According to an aspect of the present invention, there is provided a hinge unit configured to rotatably support the paper leading end alignment member such that the blocking unit selectively opens the paper feed path. And an elastic part for elastically supporting the paper leading end alignment member so that the blocking part blocks the paper transfer path.

The elastic unit, a plurality of holders supported on the rotating shaft of the second feed roller assembly; And a compression coil spring interposed between the holder and the operation portion of the paper leading end alignment member.

In addition, the drive unit, the cam member for selectively pressing the end of the operating portion to rotate the paper leading alignment member in the direction to open the paper feed path; And a motor that rotates the cam member and is driven according to a signal of the sensing unit.

In addition, the present invention is configured such that the elasticity of the flexible rotary shaft is set weaker than the elasticity of the compression coil spring, the first and second feed roller assembly is in close contact with the rotating shaft is elastically deformed when the paper leading edge alignment member rotates. do.

The above objects and other features of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. For reference, in the following description of the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

As shown in Figure 3 to Figure 6, the paper feed apparatus of the image forming apparatus according to an embodiment of the present invention is the first feed roller assembly 110, the second feed roller assembly 120, the tension idle wheel 200 , The paper leading end alignment member 300, the sensing unit 400, and the driving unit 500.

The first feed roller assembly 110 is rotatably installed on the paper feed path (C). The first conveying roller assembly 110 includes a first rotating shaft 111 and a plurality of first conveying rollers 112 and the like disposed at predetermined intervals on the rotating shaft 111. The first rotating shaft 111 is connected to a driving source (not shown).

The second feed roller assembly 120 is spaced apart from the first feed roller assembly 110 at a predetermined interval. The second feed roller assembly 120 selectively transports the paper P while being in close contact with the first feed roller assembly 110 to rotate. The second feed roller assembly 120 includes a second feed shaft 122 and a second feed roller 122 and the like arranged at a predetermined interval on the rotary shaft 121.

The second rotating shaft 121 is formed of a flexible material that is elastically deformed with respect to an external force so that the first and second transfer roller assemblies 110 and 120 selectively rotate in close contact with each other according to a feature of the present invention. This will be described later in detail.

A plurality of the tension idle wheels 200 are installed in the second feed roller assembly 120 so as to be rotatable. The tension idle wheel 200 slip-feeds the paper P while rotating in contact with the first feed roller assembly 110 while the first and second feed roller assemblies 110 and 120 are spaced apart from each other. And when the second feed roller assembly 110, 120 is in close contact with the elastic deformation in the radial direction does not interfere with the close contact with the feed roller assembly (110, 120). Meanwhile, although the tension idle wheel 200 is installed in the second feed roller assembly 120 in the drawing, the tension idle wheel 200 may be installed in the first feed roller assembly 110.

The tension idle wheel 200 as described above is provided with an outer ring 210, an inner ring 220 and the spokes 230, and is integrally formed by a material such as resin. The outer ring 210 is in contact with the feed roller 112 of the first feed roller assembly 110, the surface is smoothly processed to have a low coefficient of friction. As a result, slip occurs during contact with the paper P, thereby enabling slip conveyance of the paper.

The inner ring 220 is fitted to and supported by the rotation shaft 121 of the second feed roller assembly 120. The spokes wheel 230 connects the outer ring 210 and the inner ring 220. According to FIG. 6, four spokes 230 are formed in a bent state. The reason for forming the spokes 230 as described above is to make the tensile idle wheel 200 easily crush when subjected to an external force. In addition, the number of the spokes 230 is not limited to four of the illustrated example, but two or more is sufficient.

The paper leading end alignment member 300 is installed to selectively open the paper feed path C downstream of the first and second feed roller assemblies 110 and 120. In the state where the paper line alignment member 300 blocks the paper feed path C, the tip of the paper which is conveyed slowly while the slip is generated by the tension idle wheel 200 and the first feed roller assembly 110. The paper is aligned neatly while contacting the paper leading end alignment member 300.

The paper edge alignment member 300 as described above includes a blocking portion 310 positioned in the paper conveying path C and an operating portion 320 vertically connected to the blocking portion 310. The hinge part 330 supports the paper edge alignment member 300 in a rotatable manner so that the blocking part 310 selectively opens the paper feed path C. As shown in FIG. In addition, the elastic unit 340 elastically supports the paper line alignment member 300 so that the blocking unit 310 blocks the paper feed path (C).

The elastic portion 340 is a plurality of holders 341 supported on the rotating shaft 121 of the second feed roller assembly 120 and the operation portion 320 of the holder 341 and the paper leading end alignment member 300. And a compression coil spring 342 interposed therebetween.

The sensing unit 400 includes a plurality of sensors installed side by side in front of the blocking unit 310 of the paper leading alignment member 300 to sense whether the front end of the paper (P) is aligned. In the present embodiment, the signal transmission path of the sensor is not configured separately, and the flexible second rotation shaft 121 is configured as an optical fiber so that the signal transmission path of the sensor also functions as a rotation axis. It was. In this case, an optical sensor, an infrared sensor, an ultrasonic sensor, or the like may be used as the sensor.

The driving unit 500 rotates the paper leading alignment member 300 to open the paper transfer path C when the paper leading alignment signal is detected by the sensing unit 400, and the first and second drives. By adhering the conveying roller assemblies 110 and 120, the paper P having its front ends aligned is conveyed.

The driving unit 500 selectively presses the end of the operation unit 320 of the paper leading alignment member 300 so that the paper leading alignment member 300 rotates in the direction of opening the paper feed path C. FIG. Cam member 510, and a motor 520 for rotating the cam member 510. The motor 520 is driven according to the signal of the sensing unit 400.

In addition, the elasticity of the flexible second rotary shaft 121 is set to be weaker than the elasticity of the compression coil spring 342, so that the rotary shaft 121 elastically deforms when the paper leading edge alignment member 300 rotates. The first and second feed roller assemblies 110 and 120 are configured to be in close contact.

Hereinafter, the paper tip alignment and the paper feed of the paper feed apparatus according to the present invention configured as described above will be described with reference to FIGS. 3 and 4, 7A and 7B, and FIGS. 8 and 9.

3 and 4 are a side view and a front view 110 and a second feed roller assembly, respectively, when the tip of the picked-up paper P enters between the first and second feed roller assemblies 110 and 120, respectively. 120 is spaced apart from each other at a predetermined interval, and the tension idle wheel 200 installed on the second feed roller assembly 120 and the first feed roller assembly 110 are in contact with each other.

In the above state, the paper P entering between the tension idle wheel 200 and the first feed roller assembly 110 is conveyed by the feed force of the first feed roller assembly 110. At this time, as shown in FIG. 7A, when the paper P is conveyed in a misaligned state, one side P1 of the paper first contacts the blocking portion 310 of the paper leading alignment member 300, and in this state, A slip occurs between the first feed roller 112 and the paper P and the tension idle wheel 200, and the other side P2 of the paper P is rotated while the one side P1 of the paper is stopped. The tip is aligned neatly by contacting 310. The state where such paper leading end alignment is completed is shown in Fig. 7B.

As the front-end alignment of the paper is completed as shown in FIG. 7B, all of the plurality of sensing units 400 arranged in the width direction of the paper are sensed at a time when the state changes from 'on' to 'off' state. After the predetermined time has elapsed, the driving unit 500 is driven by a controller (not shown) to open the paper feed path C, and the first and second feed roller assemblies 110 and 120 rotate in close contact with each other. This aligned sheet | seat P is conveyed.

That is, according to FIGS. 8 and 9, the cam member 510 coupled to the shaft rotates by driving the motor 520. Accordingly, the paper leading end alignment member 300 rotates clockwise in the drawing about the hinge portion 330. Therefore, the paper conveying path C is opened by the end of the blocking part 310 being out of the paper conveying path C. FIG. At the same time, the operating unit 320 is pressed against the compression coil spring 342 of the elastic unit 340 is in close contact with the first feed roller assembly 110 while the second rotating shaft 121 is elastically deformed. At this time, the tension idle wheel 200 installed in the second feed roller assembly 120 is crushed in the radial direction and does not prevent the first and second feed rollers 112 and 122 from coming into close contact with each other.

In the above state, the paper P is conveyed along the open paper conveying path C. When the rear end of the conveyed paper is out of the plurality of sensors, the motor 520 is driven in reverse rotation so that the paper edge alignment member ( 300 and the second feed roller assembly 120 is returned to its initial state.

As described above, the present invention does not use the front end alignment of the conveyed paper as the paper feed force, but generates slips on the paper in a state in which the paper transfer path is blocked to perform the front end alignment, and then open and transport the paper transfer path. . Therefore, the leading edge alignment of the paper is efficiently performed regardless of the thickness of the paper used.

The present invention has been described in an exemplary manner. The terminology used herein is for the purpose of description and should not be regarded as limiting. Many modifications and variations of the present invention are possible in light of the above teachings. Accordingly, the invention may be freely practiced within the scope of the claims unless otherwise stated.

According to the present invention as described above, even in the case of using a thick paper, the leading edge alignment of the paper can be made smoothly, it is possible to reduce the occurrence of printing errors due to meandering of the paper.

Claims (15)

First and second feed roller assemblies rotatably installed in the paper feed path; At least one tension idle wheel installed in any one of the transfer roller assemblies, wherein the at least one tension idle wheel is elastically deformed in a radial direction when the first and second transfer roller assemblies are in close contact with each other; And And a paper leading end alignment member installed downstream of the first and second transfer roller assemblies to align the leading ends of the transferred paper. The method of claim 1, wherein the tension idle wheel, The paper conveying apparatus of the image forming apparatus, characterized in that for slip conveying the conveyed paper in the first and second conveying roller assembly spaced apart state. The method of claim 1, A sensing unit having a plurality of sensors for sensing whether the paper is aligned with the front end; And And a driving unit which drives the paper leading alignment member to rotate and close the first and second feed roller assemblies so as to open the paper feed path when the paper leading alignment signal is detected by the sensing unit. A paper conveying apparatus of an image forming apparatus. The method of claim 1, wherein the second feed roller assembly, A plurality of rollers; And And a flexible rotating shaft rotatably supporting the roller and elastically deformed with respect to an external force. The method of claim 4, wherein And the tension idle wheel is rotatably installed in the second feed roller assembly. The method of claim 5, wherein the tension idle wheel, An outer ring contacting the first feed roller assembly; An inner ring into which the rotating shaft of the second feed roller assembly is fitted; And And a plurality of spokes connecting the outer ring and the inner ring and bent at a predetermined angle in a radial direction. The method of claim 6, And 2 to 5 wheels, and the plurality of wheels are bent in the same direction. The method of claim 7, wherein And the tension idle wheel is integrally formed of a resin. The method of claim 8, And the outer ring has an outer surface that is smoothly processed to generate slip with paper. The method of claim 4, wherein And the flexible rotating shaft is formed of an optical fiber to serve as a signal transmission path of the sensor. The method of claim 4, wherein The paper leading end alignment member includes a blocking portion located in the paper conveying path and an operating portion connected vertically from the blocking portion; A hinge part for rotatably supporting the paper leading end alignment member such that the blocking part selectively opens the paper feed path; And And an elastic part for elastically supporting the paper leading end alignment member so that the blocking part blocks the paper feed path. The method of claim 11, wherein the elastic portion, A plurality of holders supported by a rotation shaft of the second feed roller assembly; And And a compression coil spring interposed between the respective holders and the actuating portion of the paper leading end alignment member. The method of claim 3, wherein the drive unit, A cam member for selectively pressing an end of the operating portion to rotate the paper leading alignment member in a direction of opening the paper feed path; And Rotating the cam member, the motor is driven in accordance with the signal of the sensing unit; Paper conveying apparatus of the image forming apparatus comprising a. The method of claim 13, The elasticity of the flexible rotary shaft is set weaker than the elasticity of the compression coil spring, so that the first and second feed roller assembly is in close contact with the rotating shaft is elastically deformed when the paper leading edge alignment member rotates. Paper feeder of the device. A first feed roller assembly rotatably installed in the paper feed path; A second feed roller assembly disposed to be spaced apart from the first feed roller assembly at a predetermined interval, the second feed roller assembly transferring the paper while selectively rotating in close contact with the first feed roller assembly; The conveying roller assembly of any one of the conveying roller assemblies is installed, and in the state in which the first and second conveying roller assemblies are spaced apart, the sheet is conveyed by slip rotation while contacting and rotating the corresponding conveying roller assembly. At least one tension idle wheel that is elastically deformed in a radial direction when the roller assembly is in close contact; A paper feed end alignment member arranged to selectively open the paper feed paths downstream of the first and second feed roller assemblies, and to align the leading edges of the paper to be slip fed by the tension idle wheel when the paper feed paths are blocked. ; A sensing unit having a plurality of sensors for sensing whether the leading edge of the paper is aligned; And And a driving unit which drives the paper leading alignment member to rotate and close the first and second feed roller assemblies so as to open the paper transfer path upon the paper leading alignment signal by the sensing unit. Paper feed apparatus of the image forming apparatus.

Images