KR100491563B1 - Paper transfer apparatus for printer - Google Patents

Abstract

Disclosed is a paper conveying apparatus of a printer capable of preventing paper feeding. According to an aspect of the present invention, there is provided a paper conveying apparatus comprising: a pickup roller which is rotationally driven in a first direction to pick up a sheet of paper; A separation roller that separates the sheet by sheet by friction with the sheet while being driven in contact with the pickup roller; A support shaft rotatably supporting the separation roller in a first direction and a second direction opposite thereto, the support shaft being rotated in the second direction when the pickup roller is rotated; When a plurality of sheets of paper are supplied between the separating roller and the pick-up roller and the friction force falls below a predetermined value, the friction force is provided to provide a predetermined friction force between the supporting shaft and the separating roller so that the separating roller rotates together with the supporting shaft. unit; And an interlocking unit interlocked with the pickup roller and providing a pressing force for pressing the separation roller toward the pickup roller side. According to this, it is possible to implement a paper transport apparatus of a printer which is inexpensive and effective in preventing heavy feeding through a simple structure.

Description

Paper transfer apparatus for printer

The present invention relates to a printer, and more particularly, to a paper conveying apparatus of a printer for supplying the paper loaded in the paper cassette to the engine unit of the printer.

In general, in conveying the paper loaded in the paper cassette of the printer to the engine unit, when two sheets of paper are overlapped and conveyed, an excessive force is applied to each component, and also a waste of paper. Therefore, the paper conveying apparatus of the printer has a feed prevention function for preventing the two sheets of paper from being fed overlapped.

1 and 2 illustrate a paper feed apparatus of a printer having a conventional non-feed function. This is briefly described as follows.

1 and 2, a conventional paper conveying apparatus includes a pickup roller 3 for picking up the paper 1 stored in the paper cassette 2 while being driven by a step motor (not shown), Separation roller (4), which is pressed against the pickup roller (3) by a spring (10), is rotatably supported by a lever (7) installed rotatably around the lever shaft (17), and separates the picked-up paper into sheets. And connected to the cam 8 by the second spring 11 and rotatably installed around the lifter shaft 18 by the rotation of the cam 8 to move the paper 1 toward the pickup roller 3. And a power transmission unit for transmitting the driving force of the lifting lifter 6 and the pick-up roller 3 to the separating roller 4.

The power transmission unit is coaxial with the gear 12 provided on the drive shaft 3a of the pickup roller 3, the first gear 15 rotated by being engaged with the gear 12, and the first gear 15. The second gear 16 is installed so as to rotate, and the separation roller gear 13 is engaged with the second gear 16 to drive the shaft 4a of the separation roller 4 to rotate.

The torque limiter 14 is installed in the first gear 15 and the second gear 16. The torque limiter 14 rotates each of the gears 15 and 16 in the same direction when the relative rotational torque of the first gear 15 and the second gear 16 is within the set torque of the torque limiter 14. If the torque is more than the set torque of the limiter 14, the power from the first gear 15 to the second gear 16 is cut off so as not to rotate together.

According to the above configuration, when one sheet of paper 1 enters between the pickup roller 3 and the separation roller 4, that is, the separation unit 19, the separation unit 19 by the first spring 10. The separation roller 4 is conveyed to the pickup roller 3 by the frictional force by the pressure welding of the) and transfers the paper 1. In this case, since the rotational torque of the separation roller 4 transmitted to the gears 13 and 16 is greater than or equal to the set torque of the torque limiter 14, the first gear 15 is independent of the second gear 16. Rotated in the opposite direction.

On the other hand, when two or more sheets of paper 1 are picked up, the separation roller 4 is the pickup roller 3 because the torque of the torque limiter 14 is larger than the friction force acting between the two sheets, that is, the paper separating force. The paper contacted to the separation roller 4 is separated and conveyed while rotating in the opposite direction of the conveying direction of the paper 1 by the power transmitted through the second gear 16 and the gear 13 without being rotated by being driven by the. Will be prevented.

By the way, the conventional paper feed apparatus of the printer has a problem that the manufacturing cost of the printer increases because the torque limiter is difficult to maintain and manufacture a uniform torque of the limiter.

In addition, since the separation roller is pressurized toward the pickup roller by cam driving, a high power motor for cam driving is required or a relatively high power consumption is required because a high power is required to increase the applied current.

The present invention has been made in view of the above problems, and the printer has been improved in structure so as to separate the conveyed paper by using the driving force of the pickup roller without changing the motor or increasing the applied current for increasing the additional driving force. The object is to provide a paper conveying apparatus.

The paper conveying apparatus of the printer according to the present invention for achieving the above object, the pickup roller is rotated in the first direction to pick up the paper; A separation roller that separates the sheet by sheet by friction with the sheet while being driven in contact with the pickup roller; A support shaft rotatably supporting the separation roller in a first direction and a second direction opposite thereto, the support shaft being rotated in the second direction when the pickup roller is rotated; When a plurality of sheets of paper are supplied between the separating roller and the pick-up roller and the friction force falls below a predetermined value, the friction force is provided to provide a predetermined friction force between the supporting shaft and the separating roller so that the separating roller rotates together with the supporting shaft. unit; And an interlocking unit interlocked with the pickup roller and providing a pressing force for pressing the separation roller toward the pickup roller side.

Here, the interlocking unit may include a drive gear installed on the drive shaft of the pickup roller, an idle gear connected to the drive gear, a driven gear installed on the support shaft to be connected to the idle gear, and the idle gear. And a swing arm connecting each of the idler shaft and the support shaft so that the support shaft can be moved about the axis. The support shaft is moved in the rotational direction of the idle gear by a moment caused by the rotation of the idle gear. Preferably, the separation roller is brought into close contact with the pickup roller.

In addition, the shaft of the idle gear is preferably provided with a paper feed roller for conveying the separated paper in a predetermined direction while being in contact rotation with the pickup roller.

The idle gear may include a first idle gear connected to the driving gear and at least one second idle gear coaxially installed with the first idle gear and connected to the driven gear.

In addition, the frictional force providing unit, it is preferable to include a coil spring interposed between the separation roller and the driven gear.

In addition, the separation roller, the surface structure is preferably formed in a helical vane wheel (Helical Vane Wheel) method.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

Figure 3 is a perspective view showing a paper transfer device of the printer according to a preferred embodiment of the present invention, Figure 4 is a side view for showing a frictional force providing unit of the paper transfer device of the printer according to a preferred embodiment of the present invention.

Referring to the drawings, the paper transport apparatus of the printer according to a preferred embodiment of the present invention, the pickup roller 110 is driven in the first direction (A) to pick up the paper 101 loaded in the paper cassette 100 And a separation roller 120 that separates the sheet of paper 101 by a frictional force from the sheet 101 while being driven and rotated in contact with the pickup roller 110 and the separating roller 120 in the first direction A. FIG. And a support shaft 121 which is rotatably supported in the second direction B, which is the opposite direction, and is rotated and driven by a driving force in the second direction B, and is in contact with the pickup roller 110 to form the paper 101. Paper feed roller 130 for feeding the paper in the discharge direction, a friction force providing unit 140 for providing a predetermined friction force between the support shaft 121 and the separation roller 120, and the separation roller while interlocking with the pickup roller 110 It includes a linkage unit 150 for providing a pressing force for pressing the 120 to the pickup roller 110 side.

The paper cassette 100 includes a support plate 102 for loading the paper 101, a coil spring (FIGS. 5 and 103) provided on an upper surface of the support plate 102 to provide a predetermined elastic force, and a coil. It is composed of a lifter 104 supported by a spring 103 to lift the paper 101.

The pickup roller 110 is coupled to a drive shaft 111 that is driven to rotate in the first direction A by a step motor (not shown) and rotates together with the drive shaft 111. The pickup roller 110 is formed of a rubber material having a large friction force as in the conventional pickup roller.

The separation roller 120 is installed to be freely rotatable on the outer circumference of the support shaft 121. The separation roller 120 is also installed to be spaced apart and accessible to the pickup roller 110. This will be described later, because the support shaft 121 can be moved in position. Subsequently, the separation roller 120 is pressed toward the pickup roller 110 by the interlocking unit 150 when the pickup roller 110 is rotated, and is driven by the pickup roller 110 to rotate the paper 101. Can be transported On the contrary, when a plurality of papers are picked up, the papers picked up are rotated in the second direction B without being driven by the friction torque provided by the frictional force providing unit 140 and separated into sheets.

The frictional force providing unit 140, when the plurality of sheets of paper is supplied between the separation roller 120 and the pickup roller 110 so that the friction force between the rollers 110, 120 falls below a predetermined value, the separation roller It is installed to provide a predetermined friction force between the support shaft 121 and the separation roller 120 so that the 120 is rotated together with the support shaft 121. The friction force providing unit 140 preferably includes a friction spring 141 interposed between the separation roller 120 and the driven gear 155 to be described later. The friction spring 141 may be, for example, a coil spring fitted to the support shaft 121, and is installed in a compressed state in contact with an end of the driven gear 155 and the separation roller 120. In addition, preferably, a pair of friction springs 141 are respectively provided at both ends of the separation roller 120 to provide a balanced friction force at both ends of the separation roller 120.

The interlocking unit 150 is connected to a drive gear 151 installed on the drive shaft 111 of the pickup roller 110, and idle gears 152 and 154 and idle gears 154 connected to the drive gear 151. And a swing arm 156 which connects the driven gear 155 to the support shaft 121 and the shaft 153 of the idle gears 152 and 154 and the support shaft 121.

The drive gear 151 is coupled to the drive shaft 111 is rotated together, it is rotated in the first direction (A).

The idle gears 152 and 154 are divided into a first idle gear 152 connected to the drive gear 151 and a second idle gear 154 coaxially connected to the first idle gear 152. Each of the idle gears 152 and 154 may be spaced apart from each other by a predetermined distance, and may be coupled to the shaft 153 to rotate in the second direction B at the same time. Here, the second idle gear 154 is provided so that a pair is spaced a predetermined distance. Then, the paper feed roller 130 is coupled between them. That is, the paper feed roller 130 is coupled to the shaft 153 and simultaneously rotates in the second direction B together with the idle gears 152 and 154 to convey the paper entering between the pickup roller 110 in a predetermined direction. Let's do it.

In addition, the second idle gear 154 is gear-connected to the driven gear 155 to rotate the driven gear 155 in the first direction (A). Of course, the driven gear 155 is provided with a pair spaced apart from each other so as to correspond to each of the pair of second idle gear 154. The driven gear 155 is coupled to the support shaft 121 is rotated together with the support shaft 121. Then, the friction spring 141 described above is interposed between each of the driven gear 155 and the separation roller 120, and the friction spring 141 consequently separates the separation roller 120 and the support shaft 121 from each other. The predetermined friction force is to act on.

The swing arm 156 connects each of the shaft 153 and the support shaft 121 such that the support shaft 121 is rotatable, that is, rotatable about the shaft 153. Both ends of the swing arm 156 are rotatably connected to the shaft 153 and the support shaft 121. As described above, when the support shaft 121 is connected to the shaft 153 by the swing arm 156, the second idler gear 154 rotates in the second direction B while the driven gear 155 is interlocked. When the moment due to the rotational force of the second idler gear 154 acts, the swing arm 156 moves the support shaft 121 while being rotated in the second direction B, as shown by the virtual line of FIG. 5. . Therefore, the separation roller 120 supported by the support shaft 121 is in close contact with the pickup roller 110.

On the other hand, the separation roller 120 is preferably the surface structure of the helical vane wheel (Helical Vane Wheel) method, which improves the friction between the separation roller 120 and the paper 101, the paper 101 This is to make it possible to separate the paper more effectively than in the case of the mid-conveying.

 Referring to the operation and effect of the paper transfer device of the printer according to a preferred embodiment of the present invention having the above configuration is as follows.

First, the operation of picking up one sheet of paper will be explained. As shown in FIG. 5, the pickup roller 110 is rotated in the first direction A to pick up the paper 101. As described above, the power of the pickup roller 110 is transmitted to the idle gears 152 and 154 through the drive gear 151. At this time, the moment is applied to the swing arm 156 by the rotational force of the second idle gear 154, the swing arm 156 is rotated a predetermined distance in the second direction (B), as shown by the imaginary line. Therefore, the separation roller 120 supported by the support shaft 121 is in close contact with the pickup roller 110 side is rotated to follow.

On the other hand, as shown in Figure 6a while the separation roller 120 is driven along with the pickup roller 110 as described above, when the sheet of paper (P1) is entered, the pickup roller 110 and the separation roller 120 ) Rotates mutually as before the sheet enters and conveys the sheet P1. Here, when the friction force between the paper P1 and the pickup roller 110 is u1, and the friction force between the paper P1 and the separation roller 120 is u2, since u1 > As the 110 is rotated, the paper P1 is transferred, and the separation roller 120 can also be driven together. On the other hand, in the present embodiment, when the friction force acting between the separation roller 120 and the support shaft 121 by the friction spring 141 is u4, the friction force u2 is sufficiently larger than u4 support shaft 121 Even though the driven gear 155 is rotated in the first direction A, the separation roller 120 conveys the paper P1 while being rotated in the second direction B irrespective of the rotation of the support shaft 121. You can do it.

On the other hand, the situation where two sheets of paper are picked up will be described as follows. Also in this case, the rotation operation of the pickup roller 110 and the close operation of the separation roller 120 to the pickup roller 110 by the swinging of the swing arm 156 proceed in the same manner.

However, as shown in FIG. 6B, when two sheets of paper P1 and P2 are simultaneously picked up and entered between the pickup roller 110 and the separation roller 120, the separation roller 120 moves in the first direction A. FIG. While rotating to separate the paper (P2) in contact with the separation roller 120 from the other paper (P1). Here, the friction force between the paper P1 and the pickup roller 110 is u1, the friction force between the paper P2 and the separation roller 120 is u2, and the friction force between the papers P1 and P2 is referred to as u1. In the case of u3, the magnitude of the mutual frictional force including the frictional force u4 is in the order of u1> u2> u4> u3. Therefore, the separation roller 120 receives power from the support shaft 121 by the friction force u4 rather than driven by the friction force u3 to the pickup roller 110, and the separation roller 120 moves in the first direction (A). Will be rotated. As such, the separation roller 120 is rotated in the first direction A, so that the lower sheet P2 is separated from the sheet P1 on the pickup roller 110 side by the friction force u2 greater than the friction force u3. It will not be picked up.

In the present embodiment as described above, the size of the friction force u4 is determined by the friction forces u2 and u3, may be appropriately designed in consideration of the material of the paper and the material of the rollers 110, 120, There is no need to limit it to a constant value.

The paper feed apparatus of the printer according to the present invention as described above uses a low-cost friction spring to selectively switch the rotational direction of the separation roller to prevent paper feeding, and thus the same as when using a conventional torque limiter. In addition to obtaining the effect of the operation has the advantage of reducing the manufacturing cost.

The present invention has been shown and described above in connection with a preferred embodiment for illustrating the principles of the present invention. However, those skilled in the art will recognize that the present invention is not limited to the configuration and operation as shown and described as such, and that many changes and modifications can be made to the present invention without departing from the spirit and scope of the appended claims. I can understand. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

1 is a perspective view showing a paper feed apparatus of a conventional printer;

2 is a side sectional view showing a paper feed apparatus of a conventional printer;

3 is a perspective view showing a paper transport apparatus of a printer according to a preferred embodiment of the present invention;

4 is a front view for showing a frictional force providing unit of a paper conveying apparatus of a printer according to a preferred embodiment of the present invention;

Figure 5 is a side view for explaining the operation of the paper feed prevention of the paper transport apparatus of the printer according to a preferred embodiment of the present invention, and

6A and 6B are side views for specifically showing the anti-feed operation.

<Explanation of symbols for the main parts of the drawings>

100; paper cassette 101; paper

102; support plate 103; coil spring

104; lifter 110; pick-up roller

111; drive shaft 120; separation roller

121; support shaft 130; paper feed roller

140; frictional force providing unit 141; friction spring

150; drive unit 151; drive gear

152,154; kids gear 153; shaft

155; driven gear 156; swing arm

Claims (6)

A pickup roller which is rotationally driven in a first direction to convey the paper so as to pick up the paper; A separation roller that separates the sheet by sheet by friction with the sheet while being driven in contact with the pickup roller; A support shaft rotatably supporting the separation roller in a first direction and a second direction opposite thereto, and being rotated and driven in the second direction when the pickup roller is rotated; When a plurality of sheets of paper are supplied between the separating roller and the pick-up roller and the friction force falls below a predetermined value, the friction force is provided to provide a predetermined friction force between the supporting shaft and the separating roller so that the separating roller rotates together with the supporting shaft. unit; And And an interlocking unit interlocked with the pick-up roller and providing a pressing force for pressing the separation roller toward the pick-up roller. According to claim 1, The linkage unit, A drive gear installed on a drive shaft of the pickup roller; An idle gear connected to the drive gear; A driven gear installed on the support shaft so as to be connected to the idle gear; And a swing arm connected to each of the shaft and the support shaft of the idle gear to move the support shaft about the axis of the idle gear. And the support shaft moves in the rotational direction of the idle gear by the moment caused by the rotation of the idle gear to closely adhere the separation roller to the pickup roller. The paper conveying apparatus of claim 2, wherein a paper feed roller is installed on a shaft of the idle gear to convey the separated paper in a predetermined direction while contacting and rotating the pick-up roller. According to claim 2 or 3, wherein the idle gear, A first idle gear connected to the drive gear; And at least one second idle gear coaxially installed with the first idle gear and connected to the driven gear. According to claim 2, wherein the frictional force providing unit, And a coil spring interposed between the separation roller and the driven gear. The separation roller according to any one of claims 1 to 5, wherein A paper conveying apparatus for a printer, characterized in that the surface structure is formed by a helical vane wheel method.