KR100555648B1 - Sheet transfering apparatus for ink jet printer - Google Patents

Abstract

The present invention relates to a paper conveying apparatus of an inkjet printer capable of conveying printing paper with a high degree of stability. The paper conveying apparatus according to the present invention comprises: a feed roller shaft having a coaxial feed roller for feeding the printing paper so that the print head performs printing; A discharge roller shaft which is coaxially installed with a discharge roller passing through the feed roller and discharging the printed paper to the outside of the ink jet printer; A motor which is provided between the feed roller shaft and the discharge roller shaft, and whose rotational shafts protruding from both ends are orthogonal to the feed roller shaft and the discharge roller shaft, respectively; First and second power transmission means which are respectively installed between both rotation shafts of the motor and the feed roller shaft and the discharge roller shaft, and transmit the driving force of the motor equally to the feed roller shaft and the discharge roller shaft; Rotation amount detecting means installed on the feed roller shaft to detect a rotation amount of the feed roller; And a control unit for controlling the motor according to the rotation amount of the feed roller detected by the rotation amount detecting means.

Feed roller, biaxial motor, worm gear, worm wheel, encoder, symmetrical structure

Description

Paper transfer device of inkjet printer {SHEET TRANSFERING APPARATUS FOR INK JET PRINTER}

1 is a perspective view showing a paper conveying apparatus of an inkjet printer according to the prior art,

Figure 2 is a perspective view showing an embodiment of a paper transport apparatus of the inkjet printer according to the present invention,

3 is a perspective view showing another embodiment of a paper conveying apparatus for an inkjet printer according to the present invention.

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

100; Feed roller 102; Feed roller shaft

110; Medium roller 112; Badge Roller Shaft

120; Motor 124; Motor shaft

130; First power transmission means 132; 1st worm wheel

134; First worm gear 140; Second power transmission means

142; Second worm wheel 144; Second War Gear

150; Rotary encoder 152; Encoder wheel

153; Slot 154; Sensing Part

160; A controller 170; frame

The present invention relates to a paper conveying apparatus of an ink jet printer, and more particularly, a motor having a rotary shaft protruding from both ends between a feed roller shaft and a discharge roller shaft, and a power transmission means having the same structure on both sides of the printing paper. The present invention relates to a paper conveying apparatus for an inkjet printer which can be stably conveyed with higher precision.

In general, an inkjet printer is a device for printing by transporting printing paper at regular intervals and then repeating an operation of spraying ink onto the printing paper with a printhead. And a paper feeding device for transferring the printing paper so that the printhead can print, and a paper feeding device for discharging the printing paper on which the printing is completed to the outside of the inkjet printer. The paper feeder is installed under the printhead and feeds the print paper at regular intervals, that is, at intervals that the printhead can print in one feed. It includes a discharge roller to discharge.

One example of a paper conveying apparatus of such an inkjet printer is shown in FIG.

Referring to FIG. 1, a paper feed apparatus according to the related art includes a feed roller 1, a discharge roller 5, a motor 9, a first gear train 17, and a second gear train 20. It includes.

The feed roller 1 for conveying printing paper is coaxially installed on the feed roller shaft 3, and the feed roller shaft 3 is rotatably supported by the frame 26. In the feed roller shaft 3, an encoder 24 for detecting the rotational amount of the feed roller 1 and a feed gear 16 for receiving power from the motor 9 are assembled. The feed gear 16 forms a first gear train 17 together with the pulley gear 13. The pulley gear 13 has a two-stage structure of the pulley portion 14 and the gear portion 15, the gear portion 15 is meshed with the feed gear 16. Power transmission between the motor 9 and the first gear train 17 fixed to the frame 26 is achieved by the belt 12. That is, the pulley 14 of the pulley gear 13 and the motor pulley 11 installed on the rotation shaft of the motor 9 are connected to the belt 12 so that the power of the motor 9 is transmitted to the pulley gear 13. . On one side of the belt 12, a tension roller 18 for adjusting the tension of the belt 12 is provided.

In addition, the delivery roller 5 for conveying the printing paper past the feed roller 1 to the outside of the ink jet printer is coaxially installed on the delivery roller shaft 7, and both ends of the delivery roller shaft 7 are connected to the frame 26. Is supported by rotation. At one end of the discharge roller shaft 7, a discharge gear 22 is assembled. The discharge gear 22 forms the second gear train 20 together with the idle gear 21, and the idle gear 21 is meshed with the feed gear 16 of the first gear train 17. Therefore, when the feed roller 1 rotates, the discharge roller 5 also rotates. At this time, the number of teeth and the like of the idle gear 21 and the discharge gear 22 constituting the second gear train 20 is the same as the number of revolutions of the feed roller 1 rotated by the first gear train 17. The discharge roller 5 is fixed to rotate.

Referring to the operation of the paper conveying apparatus of the inkjet printer according to the prior art having the above structure is as follows.

When the rotating shaft of the motor 9 rotates by a signal of a controller (not shown), the motor pulley 11 rotates. When the motor pulley 11 rotates, the pulley part 14 is rotated by the belt 12 which connects the motor pulley 11 and the pulley part 14 of the pulley gear 13. When the pulley part 14 of the pulley gear 13 rotates, the gear part 15 of the pulley gear 13 integrated with the pulley part 14 also rotates, and the gear part 15 of the pulley gear 13 is rotated. When rotates, the feed gear 16 engaged with the gear unit 15 also rotates. When the feed gear 16 rotates, the feed roller shaft 3 on which the feed gear 16 is installed rotates. When the feed roller shaft 3 rotates, the feed roller 1 coaxially coupled to the feed roller shaft 3 is rotated. ) Rotates to convey the print paper. At this time, the control unit detects the amount of rotation of the feed roller 1 through a signal from the encoder 24 and uses this information to control the motor 9 so that the printing paper can be fed at regular intervals.

When the feed gear 16 rotates, the idle gear 21 engaged with the feed gear 16 rotates, and when the idle gear 21 rotates, the discharge gear 22 engaged with the idle gear 21 also rotates. do. When the discharge gear 22 rotates, the discharge roller shaft 7 provided with the discharge gear 22 rotates, and when the discharge roller shaft 7 rotates, the discharge roller 5 coaxially coupled to the discharge roller shaft 7 ) Rotates and passes the feed roller (1) to discharge the printing paper is completed to the outside of the printer.

In other words, when the motor 9 rotates, the feed roller 1 and the discharge roller 5 rotate at the same speed, transfer the printing paper to print, and discharge the printed paper to the outside of the inkjet printer. .

By the way, the conventional paper feed device as described above uses a motor (9) in which the rotation axis is protruding only one side, so the path for transmitting power from the motor (9) to the feed roller (1) and the discharge roller (5) is long, In addition, since the power is transmitted by the belt and the plurality of gears, the power transmission errors generated by the belts and the respective gears are overlapped, thereby increasing the printing paper conveying error.

In addition, since the conventional art uses a single-axis motor with a rotating shaft protruding only on one side, a power transmission structure from the motor 9 to the feed roller 1 and a power transmission structure from the motor 9 to the discharge roller 5 are provided. Will be different. Therefore, the power transmission error generated in the feed roller 1 and the power transmission error generated in the discharge roller 5 are different. Therefore, even if the motor 9 rotates by a certain amount, since the rotation amount of the feed roller 1 and the rotation amount of the discharge roller 5 are different from each other, the feed error of the printing paper and the discharge roller 5 shown in the feed roller 1 The feed error shown is different. Therefore, the printing paper is conveyed in the state of being bitten only by one of the feed roller 1 or the discharge roller 5, and the printing paper is conveyed in the state of being bitten by the feed roller 1 and the discharge roller 5 at the same time. In this case, the conveyance of printing paper is different.

That is, the inkjet printer having the paper conveying apparatus according to the prior art has a problem that various image quality defects are generated because the conveying interval of the printing paper is changed by the feed errors of the feed roller and the discharge roller as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a paper conveying apparatus of an inkjet printer with a shortage of conveying errors of printing paper by shortening a power transmission path from a motor to a feed roller and a discharge roller.

In addition, another object of the present invention is to provide a paper conveying apparatus of an inkjet printer, by which the power transmission structure from the motor to the feed roller and the discharge roller is the same, so that the conveyance error of the printing paper is constant.

It is still another object of the present invention to provide a paper conveying apparatus for an inkjet printer having a simple structure.

An object of the present invention as described above, in the paper conveying apparatus of the ink-jet printer for transferring the print paper so that the print head can perform printing, the feed roller for feeding the printing paper spaced so that the print head to perform printing A feed roller shaft coaxially installed; A discharge roller shaft which is coaxially installed with a discharge roller passing through the feed roller and discharging the printed paper to the outside of the ink jet printer; A motor installed between the feed roller shaft and the discharge roller shaft, and the rotation shafts of both sides protruding from both ends are orthogonal to the feed roller shaft and the discharge roller shaft, respectively; First and second power transmission means respectively installed between both rotation shafts of the motor, the feed roller shaft, and the discharge roller shaft, and transmitting the driving force of the motor equally to the feed roller shaft and the discharge roller shaft; Rotation amount detecting means installed on the feed roller shaft and detecting a rotation amount of the feed roller; And a control unit for controlling the motor in accordance with the rotation amount of the feed roller detected by the rotation amount detecting means.

Here, the first and second power transmission means is preferably composed of worm gears respectively installed on both rotation shafts of the motor and worm wheels respectively provided on the feed roller shaft and the discharge roller shaft.

In addition, the first and second power transmission means is preferably a gear box.

In addition, the rotation amount detecting means is preferably a rotary encoder.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of a paper transport apparatus of the inkjet printer according to the present invention.

2 is a perspective view showing an embodiment of a paper conveying apparatus of an inkjet printer according to the present invention.

Referring to FIG. 2, the paper conveying apparatus of the inkjet printer according to the present invention includes a feed roller shaft 102 having coaxial feed roller 100, a discharge roller shaft 112 coaxially provided with discharge roller 110, and a rotating shaft. First and second power transmission means (130,140) for transmitting the driving force of the motor 120, the drive 120 of the motor (120) to the feed roller shaft 102 and the discharge roller shaft 112, respectively; , Rotation amount detecting means 150 for detecting the rotation amount of the feed roller 100, and the control unit 160.

The feed roller shaft 102 is positioned below the print head (not shown), and a feed roller 100 for conveying printing paper supplied from a paper feeder (not shown) is installed on the coaxial shaft, and both ends thereof are connected to the frame 170. It is supported by rotation. Between the frame 170 and the feed roller shaft 102 is interposed a rotational movement supporting element 104 for supporting the rotational movement of the feed roller shaft 102, such as a bearing.

In the discharge roller shaft 112, a discharge roller 110 for discharging the printing paper conveyed by the feed roller 100 to the outside of the inkjet printer is installed on the coaxial shaft, and both ends thereof are rotatably supported by the frame 170. . Similarly to the feed roller shaft 102, there is interposed between the frame 170 and the discharge roller shaft 112 to support the rotational movement of the discharge roller shaft 112, such as a bearing.

The rotating shaft 124 is protruded from both ends of the motor 120, and the rotating shaft 124 at both ends is installed at one side of the frame 170 so as to intersect the feed roller shaft 102 and the discharge roller shaft 112, respectively. . At this time, it is preferable to install the motor 120 so that the rotation shaft 124, the feed roller shaft 102, and the discharge roller shaft 112 at both ends of the motor 120 are perpendicular to each other.

The first power transmission means 130 is installed between the left rotating shaft 122 (see FIG. 3) and the feed roller shaft 102 of the motor 120, and the right rotating shaft 124 and the discharge roller shaft ( Second power transmission means 140 is installed between the 112. It is a feature of the present invention that the first and second power transmission means (130, 140) have a symmetrically identical structure. When the first and second power transmission means (130, 140) have the same structure, the feed error of the feed roller 100 and the motor generated by the power transmission system for transmitting power from the motor 120 to the feed roller 100 The transfer error of the discharge roller 110 generated by the power transmission system for transmitting power from the 120 to the discharge roller 110 is almost the same. Therefore, the amount of conveyance in the case where the printing paper is conveyed only to the feed roller 100, when conveyed only by the discharge roller 110, and when conveyed together by the feed roller 100 and the discharge roller 110 is almost the same. do. As shown in FIG. 2, the first and second power transmission means 130 and 140 may include first and second worm gears 134 and 144 assembled to rotation shafts 122 and 124 at both ends of the motor 120, respectively. It is preferable that the first and second worm wheels 132 and 142 are assembled to one end of the feed roller shaft 102 and the discharge roller shaft 112, respectively. The power transmission structure by the worm gears 134 and 144 and the worm wheels 132 and 142 has a large reduction ratio, so that the installation space can be reduced compared to other gear structures of the same reduction ratio, and stable power transmission can be achieved. have. As another embodiment of the first and second power transmission means 130 and 140, a gearbox may be used. However, the gearbox that can be used is a structure capable of transmitting the power of the motor 120 to the feed roller shaft 102 or the discharge roller shaft 112 orthogonal to each other, and should have a reduction ratio required.

The rotation amount detecting means 150 detects the rotation amount of the feed roller 100, and may use any sensor that can detect the rotation amount, such as a rotary encoder. In this example, a rotary encoder was used. The encoder wheel 152 of the rotary encoder 150 is installed at one end of the feed roller shaft 102, that is, one side of the worm wheel 132, and the sensing unit 154 has a slit 153 of the encoder wheel 152 that rotates. It is installed in the frame 170 so as to read.

In addition, as another method of installing the rotary encoder 150, as shown in the embodiment of FIG. 3, the encoder wheel 152 'may be installed at the end of one side rotation shaft 122 of the motor 120. In this case, since the encoder wheel 152 'is provided on the rotary shaft 122 of the motor 120 that rotates at high speed before deceleration, the encoder wheel 132 installed on the feed roller shaft 102 that is decelerated and rotates as shown in FIG. When the encoder wheel 152 ′ having the same resolution as the wheel 152 is used, the amount of rotation of the feed roller 100 can be controlled with a high accuracy corresponding to the reduction ratio of the first power transmission means 130. . Therefore, when the feed roller 100 is to be controlled with the same precision as the paper feeder (see FIG. 2) provided with the encoder wheel 152 on the feed roller shaft 102, that is, the number of slits 153 is lower. Because of this, it is possible to use an encoder wheel with a small radius.

The control unit 160 detects the rotation amount of the feed roller 100 from the signal of the rotation amount detecting means 150, and uses the detected rotation amount to feed the feed roller 100 to the printing paper at intervals. 120). The controller 160 controls the printhead to perform printing by ejecting ink while the printhead moves to the left and right with respect to the print paper.

Hereinafter, the operation of the paper transfer device of the inkjet printer according to the present invention having the above configuration will be described with reference to FIG. 2.

When power is supplied to the motor 120 by a signal of the controller 160, the rotation shafts 122 and 124 protruding from both ends of the motor 120 rotate. When the rotation shafts 122 and 124 on both sides rotate, the first and second worm gears 134 and 144 assembled to the rotation shafts 122 and 124 respectively rotate. When the first and second worm gears 134 and 144 rotate, the first and second worm wheels 132 and 142 engaged with the first and second worm gears 134 and 144 rotate. When the first worm wheel 132 is rotated, the feed roller shaft 102 is installed, the first worm wheel 132 is installed. When the feed roller shaft 102 rotates, the feed roller 100 coaxially installed on the feed roller shaft 102 rotates to feed the print paper. At this time, the encoder wheel 152 coaxially installed at one end of the feed roller shaft 102 is rotated together with the feed roller shaft 102, the slit 153 of the encoder wheel 152 is rotated by the sensing unit 154. Detects and transmits to the control unit 160. Then, the controller 160 detects the rotation amount of the feed roller 100 using the signal from the sensing unit 154. Therefore, the controller 160 may control the feed roller 100 to convey the printing paper by controlling the motor 120 according to the detected rotation amount of the feed roller 100.

In addition, when the second worm wheel 142 rotates, the discharge roller shaft 112 provided with the second worm wheel 142 is rotated. When the delivery roller shaft 112 rotates, the delivery roller 110 coaxially installed on the delivery roller shaft 112 rotates to discharge the printing paper conveyed from the feed roller 100 to the outside of the inkjet printer.

By the way, since the power transmission structure from the motor 120 to the discharge roller 110 has the same structure as the power transmission structure from the motor 120 to the feed roller 100, the discharge roller 110 is a feed roller ( Print paper is transported at the same speed and the same transport error as 100). Therefore, the feed amount of the print paper when the print paper is bitten only by the feed roller 100 and the feed amount of the print paper when the print paper is bitten by the discharge roller 110 are the same. In addition, when the printing paper is fed to both sides of the feed roller 100 and the discharge roller 110, the feed amount of the printing paper is also transferred to the feed roller 100 or the discharge roller 110 in a state of being bitten only. Same as feed amount.

That is, in the paper conveying apparatus of the ink jet printer according to the present embodiment, the power transmission structure from the motor 120 to the feed roller 100 is simple with the worm gears 134 and 144 and the worm wheels 132 and 142. Since the power transmission structure from the motor 120 to the feed roller 100 is symmetrically identical to the power transmission structure from the motor 120 to the discharge roller 110, the power transmission structure from the motor 120 The printing error of the generated printing paper is smaller than that of the conventional paper conveying apparatus, and the feeding error of the printing paper by the feed roller 100 and the feeding error by the discharge roller 110 are the same.

As described above, according to the paper conveying apparatus of the inkjet printer according to the present invention, since the power transmission structure from the motor to the feed roller or the discharge roller is simple, the conveyance error of printing paper is reduced.

Further, according to the present invention, it is possible to provide a paper conveying apparatus of an inkjet printer having the same feed error of printing paper by the feed roller and feed error of printing paper by the discharge roller.

In addition, according to the present invention, since power is directly transmitted to the feed roller and the discharge roller from the motor having the rotating shaft protruding on both sides, it is possible to provide a paper conveying apparatus of an inkjet printer having a simple power transmission structure.

Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described specific embodiments, and the technology to which the present invention belongs without departing from the gist of the present invention as claimed in the following claims. Those skilled in the art will be able to implement various modifications.

Claims (4)

A paper conveying apparatus of an inkjet printer for conveying printing paper so that a printhead can perform printing, A feed roller shaft provided with a coaxial feed roller for feeding the print paper apart so that the print head performs printing; A discharge roller shaft which is coaxially installed with a discharge roller passing through the feed roller and discharging the printed paper to the outside of the ink jet printer after printing is completed; A motor installed between the feed roller shaft and the discharge roller shaft, and the rotation shafts of both sides protruding from both ends are orthogonal to the feed roller shaft and the discharge roller shaft, respectively; First and second power transmission means respectively installed between both rotation shafts of the motor, the feed roller shaft, and the discharge roller shaft, and transmitting the driving force of the motor equally to the feed roller shaft and the discharge roller shaft; Rotation amount detecting means installed on the feed roller shaft and detecting a rotation amount of the feed roller; And And a control unit for controlling the motor in accordance with the rotation amount of the feed roller detected by the rotation amount detecting means. The paper conveying apparatus of claim 1, wherein the first and second power transmission means are worm gears respectively installed on both rotation shafts of the motor and worm wheels respectively installed on the feed roller shaft and the discharge roller shaft. . The paper conveying apparatus of claim 1, wherein the first and second power transmission means are gear boxes. The paper conveying apparatus of an inkjet printer according to any one of claims 1 to 3, wherein said rotation amount detecting means is a rotary encoder.

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