KR100529342B1 - Inkjet printer and paper feeding method of inkjet printer - Google Patents

Abstract

The disclosed inkjet printer includes a tip resistance member which contacts the leading edge of the paper so that the topmost sheet of paper loaded on the stacker is separated by rigidity and picked up from the stacker, and an angle for converting the inclination angle with respect to the leading edge of the paper of the leading resistance member. And a switching gear moved by the carriage to the first position for driving the pickup roller and the second position for driving the angle conversion unit by the carriage. By such a configuration, it is possible to stably separate and convey thick paper having a relatively high rigidity from ordinary paper, thereby reducing paper transport errors.

Description

Inkjet printer and paper feeding method of inkjet printer

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an inkjet printer and a paper conveying method of an inkjet printer, and more particularly, to a printer and a paper conveying method of separating and conveying stacked paper by rigidity of paper.

Generally, a printer loads a plurality of sheets into a cassette, and draws and transfers sheets one by one. As a method of separating sheet by sheet, there are generally a friction separation method using a friction plate and a tip resistance method using a paper rigidity.

1 shows a process of separating paper by the tip resistance method.

1, a plurality of sheets are stacked in the cassette 51. As shown in FIG. The pickup roller 52 is pressed onto the stacked paper P. A tip resistance member 53 having a predetermined inclination angle A is provided at the tip end of the paper P. When the pickup roller 52 is rotated, the paper P starts to be conveyed. At this time, two or more sheets P are generally conveyed by the friction force between the sheets P. FIG. The frictional force between the pickup roller 52 and the paper P is larger than the frictional force between the papers P. As shown in FIG. Therefore, when the tips of the sheets P come in contact with the tip resistance member 53, only the sheets P1 positioned at the uppermost side and in contact with the pickup roller 52 are slipped and conveyed with the sheets P positioned below them. . Then, as the front end of the paper P1 is bent, a curl is generated as indicated by the reference numeral C1 in FIG. As the pickup roller 52 is rotated, the curved portion is enlarged as indicated by the reference numeral C2, and the curved portion is unfolded momentarily as indicated by the reference numeral C3 by the rigidity of the paper P1, and only the paper P1 is separated and conveyed. .

The inclination angle A of the tip resistance member 53 is selected to be suitable for plain paper which is generally used. Therefore, when the thick paper having a high rigidity is used, after the tip of the paper P reaches the tip resistance member 53, the separation process of C1, C2, C3 of FIG. 1 is not performed or is incompletely performed, thereby causing heavy feeding. Or a pickup error in which the paper P is not conveyed may occur. In addition, an excessive load may be applied to a driving motor (not shown) for driving the pickup roller 52.

In order to solve such a problem, in the case of thick paper, it is necessary to slightly increase the inclination angle A of the tip resistance member 53. 2, the tip resistance member 53 is rotatably installed and elastically biased by a spring 54. As shown in FIG. Then, when the thick paper P having a large rigidity is transferred, the distal end member 53 is rotated as indicated by the reference B, thereby reducing the load on the driving motor (not shown) and separating the process from C1 to C3. Is performed. However, in such a configuration, even in the case of plain paper, the angle of inclination (A) may change little by little, which may cause heavy feeding.

The present invention was created to solve the above problems, and improved inkjet printer and paper transfer to convert the inclination angle of the tip resistance member in order to stably separate and transport the thick paper with relatively large rigidity Its purpose is to provide a method.

The inkjet printer of the present invention for achieving the above object is a pickup roller for picking up paper from a cassette loaded with paper, and the paper so that the paper on the uppermost side of the loaded paper is separated by rigidity and picked up from the cassette. An inkjet printer comprising a tip resistance member in contact with a tip of a feed roller, and a feed roller for transferring the paper, comprising: an angle conversion unit for converting an inclination angle of the tip resistance member with respect to the tip of the paper; And a switching gear which is moved by a carriage to a first position for driving the pickup roller and a second position for driving the angle conversion unit.

In one embodiment, the switching gear may be installed to be slid to the first position and the second position at one end of the feed roller. The switching gear is elastically biased to move to the first position, and the switching gear may be moved to the second position by a carrier.

In one embodiment, the angle conversion unit, a rotating member having a gear portion connected to the switching gear and a screw portion formed coaxially with the gear portion; A sliding member having an inclined portion and connected to the screw portion to linearly move; A support member provided with the tip resistance member and rotated in contact with the inclined portion; It may include; an elastic member for elastically biasing the support member in the direction in contact with the inclined portion.

The paper transfer method of the inkjet printer according to the present invention comprises a cassette for loading a paper, a leading resistance member for separating the paper loaded on the uppermost side of the stacked paper by the rigidity of the paper, and the edge of the paper of the leading resistance member. A paper transfer method of a printer comprising an angle conversion unit for converting an inclination angle with respect to a feed roller and a pickup roller driven by a driving motor, and an encoder for generating a count proportional to an amount of rotation of the feed roller and the pickup roller. A pickup step of rotating the pickup roller to pick up paper from the cassette; If the tip of the picked-up paper is not detected by the first paper detector within a predetermined time period, driving the angle conversion unit to convert the inclination angle of the tip resistance member and then performing the pickup step again; Characterized in that.

In addition, the paper conveying method may be performed when the current limiting error exceeds the set threshold current amount and / or the counting error of the encoder exceeds the set reference interval. The method may further include a retrying step of driving the angle conversion unit to convert the inclination angle of the tip resistance member and then performing the pickup step again.

Here, the inclination angle of the tip resistance member after the conversion is preferably larger than the initial inclination angle. The angle conversion unit is preferably driven by the drive motor.

The retrying step may include: selectively moving a switching gear rotated by the driving motor by moving a carrier to a first position driving the pickup roller and a second position driving the angle conversion unit; And converting the inclination angle by the angle conversion unit.

Converting the inclination angle of the tip resistance member, converting the inclination angle of the tip resistance member to the maximum or minimum inclination angle; Converting the difference between the maximum or minimum tilt angle and the tilt angle to be converted into a counting amount of the encoder; And driving the angle conversion unit until the counting amount of the encoder becomes the converted counting amount.

In addition, the fraudulent paper transfer method may further include converting the inclination angle of the tip resistance member into an inclination angle suitable for the paper according to the paper information transmitted from the printer driver of the host computer before performing the first pickup step. can do.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic structural diagram of an embodiment of a printer according to the present invention. This embodiment is an inkjet printer which prints an image on paper by ejecting ink droplets.

Referring to FIG. 3, a cassette 110 in which a plurality of sheets of paper P is stacked and a feed roller 140 that picks up sheets of paper P from the cassette 110 and feeds the sheets of paper P at a predetermined speed are supplied. The pickup roller 120 and the drive roller 130 are shown. The pickup roller 120 is rotated by being pressed against the paper P loaded in the cassette 110 only while the paper P is picked up, and is spaced apart from the paper P when the pickup is completed. The driven roller 141 is press-contacted to the feed roller 140. The driven roller 131 is pressed against the drive roller 130. Reference numeral 170 is a tip resistance member for separating the sheet of paper P by sheet by the tip resistance method. Reference numeral 150 denotes a printhead which prints an image by ejecting ink droplets onto the paper P. FIG. The print head 150 is mounted on the carriage 151 which is reciprocated by the carriage motor 160 in the direction perpendicular to the conveying direction of the paper P. As shown in FIG. The drive motor 180 drives the pickup roller 120, the drive roller 130, and the feed roller 140. Reference numeral 70 denotes a current detector that detects a driving current amount of the driving motor 180. Reference numeral 80 is an encoder for generating a count proportional to the rotation amount of the feed roller 140 and the pickup roller 120. Reference numeral 91 is a first paper detection unit that detects the paper P in front of the feed roller 140. Reference numeral 90 denotes a control unit for controlling the paper transfer process and the printing process of the printer.

4 is a perspective view briefly showing the paper conveying system of the embodiment shown in FIG.

Referring to FIG. 4, the first gear 1 and the encoder 80 are coupled to one end of the shaft 142 of the feed roller 140. The driving motor 180 is connected to the gear 1 through the belt 181 and the pulley 182 to rotate the feed roller 140. The other end of the shaft 142 of the feed roller 140, the switching lever 144 and the switching gear (2) is in turn coupled. The switching gear 2 is elastically biased toward the switching lever 144 by the compression spring 145.

The pick-up shaft 200 is installed on the bracket 190. As shown in FIG. 5, the inner side 192 of the bracket 190 is provided with a gear 3 connected to the switching gear 2 and a first gear train 210 for driving the drive roller 130. The pickup arm 200 is installed to rotate the pickup arm 240. The pickup arm 240 is provided with a pickup roller 120 and a second gear train 220 as shown in FIG. The outer side 191 of the bracket 190 is provided with a third gear train 230 for driving the rotating member 410 to be described later, as shown in FIG.

The carriage 151 is moved along the shaft 153 in the direction of the arrow 154 of FIG. 4 by the carriage motor 160. The carriage 151 has a first moving section for reciprocating for printing and a second moving section for moving the switching gear 2. While the carriage 151 is reciprocating in the first movement section, the changeover gear 2 is connected to the first and second gear trains 210 and 220 to drive the pickup roller 120 and the drive roller 130. It is elastically biased by the compression spring 145 to be located in the first position. When the carriage 151 pushes the switching lever 144 while moving to the second section, the switching gear 2 is connected to the third gear train 230 to move to the second position for rotating the rotating member 410 of FIG. 9. do.

5 shows the first gear train in detail. Referring to FIG. 5, the gear 4 connected to the gear 3 is coupled to the pickup shaft 200. In addition, a swing bracket 250 having a first arm 251 and a second arm 252 is coupled to the pickup shaft 200 so as to be rotatable. The gear 5 is coupled to the first arm 251. Gear 6 and gear 7 coupled to each other are coupled to second arm 252. Gear 5 and gear 6 are respectively connected with gear 4. When the feed roller 140 is rotated in the direction F1 which is opposite to the conveying direction of the paper P, the swing bracket 250 is rotated in the direction G1 so that the gear 5 is connected to the gear 8. When the feed roller 140 is rotated in the F2 direction, which is the feed direction of the paper P, the swing bracket 250 is rotated in the G2 direction so that the gear 7 is connected to the gear 8. The gear 8 is connected to the gear 9 coupled to one end of the drive roller 130.

6 illustrates the second gear train in detail. 6, the gear 10 is coupled to the pickup shaft 200. The pickup arm 240 is installed to be rotated on the pickup shaft 200. The pickup roller 120 is installed at the end of the pickup arm 240. The gear 13 coupled to the pickup roller 120 is connected to the gear 10 through the gear 11 and the gear 12. When the feed roller 140 is rotated in the F1 direction, the pick-up arm 240 is rotated in the H1 direction to transport the paper P while the pickup roller 120 is pressed against the paper P. FIG. When the feed roller 140 is rotated in the F2 direction, the pickup arm 240 is rotated in the H2 direction so that the pickup roller 120 is spaced apart from the paper (P).

7 illustrates the third gear train in detail. Referring to FIG. 7, a gear 14 is shown which is connected with the changeover gear 2 when the changeover gear 2 is in the second position. Gears 15, 16, 17 are in turn connected from gear 14. Gear 17 is connected to the gear portion 18 of the rotating member 410,

The printer of this embodiment is characterized in that it is possible to convert the inclination angle of the front end portion of the paper P of the front end resistance member 170 in the process of picking up the paper P as shown in FIG. In this embodiment, the tip resistance member 170 is installed on the support member 430 and the inclination angle of the tip resistance member 170 is changed by rotating the support member 430. In general, plain paper (thickness about 100 µm or less) is better separated at a small inclination angle than relatively thick paper (thickness about 100 µm or more).

9 shows an example of the angle conversion unit for converting the inclination angle of the tip resistance member 170.

9, the rotating member 410, the sliding member 420, and the plurality of supporting members 430 are illustrated. The rotating member 410 is provided with a gear portion 18 and a screw portion 411, the screw portion 411 may be integrally formed with the gear portion 18 or manufactured separately and coupled to the gear portion 18. The sliding member 420 is provided with an inclined portion 421. One end of the sliding member 420 is provided with a female screw portion 422 coupled with the screw portion 411. The sliding member 420 is slid in the M1 or M2 direction according to the rotation direction of the rotating member 410. The tip resistance member 170 is installed on the support member 430. An interference part 431 is provided on the rear surface of the support member 430 to interfere with the inclined part 421. A plurality of tension springs 440 are installed on the rear surface of the support member 430. The tension spring 440 elastically biases the support member 430 to be rotated at the second inclination angle A2.

Now, a paper transfer method will be described with reference to Figs. 10 and 3 to 9 and a front end resistance separation scheme showing a flowchart of an embodiment of a paper transfer method of an inkjet printer according to the present invention.

When a print command is transmitted from the host (not shown), the drive motor 180 rotates the feed roller 140 in the F1 direction to pick up the paper P from the cassette 110. The switching gear 2 is elastically biased to be located in a first position connected with the gear 3 by the compression spring 145. Therefore, the rotational force of the driving motor 180 is transmitted to the first and second gear trains 210 and 220. Then, as shown in FIG. 6, the pickup arm 240 is rotated in the H1 direction, and the pickup roller 120 contacts and rotates the paper P loaded on the cassette 110 (S1). At this time, as shown in FIG. 5, the swing bracket 250 is rotated in the direction G1 so that the gear 5 is connected to the gear 8 so that the drive roller 130 is rotated in the direction of the arrow in FIG. 5. As the pick-up roller 120 is rotated, the paper P loaded on the uppermost side of the cassette 110 is separated from the paper P loaded below through the processes C1, C2 and C3 of FIG. ), And is transferred to the first paper detection unit 91 by the drive roller 130.

When the leading edge of the paper P is detected within the time set by the first paper detector 91 (S3), the controller 90 determines that the pickup process has been successfully performed. After the front end of the paper P is detected by the first paper detection unit 91, the front end of the paper P is aligned with the feed roller 140 (S4), and then the driving motor 180 feeds the feed roller 140. Rotate in the direction of F2. Then, the paper P is conveyed between the feed roller 140 and the driven roller 141 (S5). The print head 150 prints an image by ejecting ink droplets onto the paper P (S6). At this time, as shown in FIG. 5, the swing bracket 250 is rotated in the G2 direction so that the gear 5 is spaced apart from the gear 8 and the gear 7 is connected to the gear 8. Thus, the drive roller 130 continues to rotate in the direction of the arrow in FIG. 6, the pick-up arm 240 is rotated in the H2 direction and the pick-up roller 120 is spaced apart from the paper P. As shown in FIG. As such, after the pickup of the paper P is completed, the load on the driving motor 180 can be reduced by separating the pickup roller 120 from the paper P. FIG.

If the leading edge of the paper P is not detected within the time set by the first paper detection unit 91 (paper detection error) (S3), the control unit 90 of the paper P once loaded in the cassette 110 is stored. Compared with the rigidity, the inclination angle of the tip resistance member 170 is not appropriate, so it is determined that the paper P is not transported due to the tip resistance member 170. In this case, although the paper P cannot be conveyed from the cassette 110 by slipping between the pickup roller 120 and the paper P, the pickup roller 120 and the feed roller 140 are normally rotated, so that the encoder ( The count of 80 is generated normally.

The controller 90 moves the carrier 151 to push the switching lever 144 to change the inclination angle of the tip resistance member 170 to move the switching gear 2 to the second position. Then, the switching gear 2 is connected to the third gear train 230 so that the rotational force of the drive motor 180 is transmitted to the rotating member 410. When the rotating member 410 is rotated, the sliding member 420 is slid in the M1 or M2 direction. Then, the inclination angle of the support member 430 is converted by the interference between the inclined portion 421 and the interference portion 431 (S8). In general, the occurrence of slip between the pickup roller 120 and the paper P means that the inclination angle of the tip resistance member 170 is too small. Therefore, it is preferable that the inclination angle A2 of the tip resistance member 170 after conversion is larger than the inclination angle A1 before conversion.

The controller 90 rotates the rotating member 410 in a direction in which the inclination angle of the tip resistance member 170 increases. At this time, since the feed roller 140 is also rotated, by checking the count amount of the encoder 80, it is possible to check how large the inclination angle is from the first inclination angle. In converting the inclination angle of the tip resistance member 170, first, the tip resistance member 170 is converted to have a minimum or maximum inclination angle, and then the difference between the maximum or minimum inclination angle and the inclination angle to be converted is determined by the encoder 80. It is converted into count amount of). Then, when the rotating member 410 is rotated until the converted count amount is reached, the inclination angle of the tip resistance member 170 can be converted into a desired inclination angle.

In the case where the inclination angle of the tip resistance member 170 is not appropriate compared to the rigidity of the paper P loaded in the cassette 110, and the paper P is not transported due to the tip resistance member 170, FIG. As shown, the pick-up arm 240 has a tendency to rotate in the H1 direction, so that the pick-up roller 120 presses the upper surface of the paper P strongly. Therefore, the load of the driving motor 180 is increased and eventually the driving motor 180 may be out of order. When the load applied to the driving motor 180 is increased, the amount of driving current for driving the driving motor 180 is also increased. When this amount of drive current exceeds the set limit current amount (current limit error), the drive motor 180 is forged. When the driving motor 180 is out of order, the pickup roller 120 and the feed roller 140 are not rotated. In this embodiment, the encoder 80 is installed in the feed roller 140. The counting interval of the encoder 80 is greater than the time interval calculated by the rotational speed of the drive motor 180 and the reduction ratio from the drive motor 180 to the feed roller 140 or is counted by the encoder 80 for a predetermined time. If does not occur (encoder counting error) it can be seen that the drive motor 180 is out of order.

In this way, if any one of the current limiting error and the counting error is detected (S2), the control unit 90 does not wait for the front end of the paper P to be detected by the first paper detection unit 91 as described above. The inclination angle of the resistance member 170 is converted (S8).

After converting the inclination angle of the tip resistance member 170, the control unit 90 moves the carrier 151 so that the switching gear 2 is the first and second gear train 210 by the elastic force of the compression spring 145. To be moved to a first position connected to the 220. As the driving motor 180 is rotated, the pickup roller 120 picks up the paper P again. Since the inclination angle of the tip resistance member 170 is larger than the initial inclination angle, the resistance applied to the tip of the paper P by the tip resistance member 170 is reduced. Therefore, the thick paper having a high rigidity is also separated and transported through the C1 to C3 process of FIG. 1. If the leading edge of the paper P is not detected within the time set by the first paper detection unit 91 or at least one of the current limiting error and the encoder counting error occurs, the inclination angle of the leading resistance member 170 is changed again. Try to pick up again after converting to a larger size. If the number of times of retrying exceeds the set number of times, the control unit 90 stops the transfer of the paper P (S7).

Conventionally, the inclination angle of the tip resistance member 170 is fixed at an angle suitable for separating ordinary paper, which is generally used, so that thick paper having a large rigidity does not separate well so that a heavy feeding occurs or the tip resistance is too large. As described above, there is a possibility that a pick-up error may occur that is not transported. However, according to the inkjet printer and the paper conveying method according to the present embodiment, the paper detection error, the current limiting error, and the encoder counting error are detected in the process of picking up the paper, and the inclination angle of the tip resistance member 170 is determined by the rigidity of the paper. The paper pick-up error can be reduced by sequentially converting and retrying pickup.

The paper transfer method of the inkjet printer according to the present invention converts the inclination angle of the tip resistance member 170 to an appropriate inclination angle according to the paper information transmitted from the printer driver of the host computer (not shown) before performing the first pickup step. can do. That is, when the type of the paper P loaded in the cassette 110 is input from the host computer, the control unit 90 rotates the rotating member 410 to input the paper P into which the inclination angle of the tip resistance member 170 is input. ) Make the angle of inclination suitable for separation. According to this method, the paper pick-up error can be significantly reduced.

As described above, according to the printer and the paper conveying method according to the present invention, it is possible to stably separate and transport both plain paper and thick paper having a relatively high rigidity, thereby reducing paper conveying errors.

It is to be understood that the invention is not limited to that described above and illustrated in the drawings, and that more modifications and variations are possible within the scope of the following claims.

1 is a cross-sectional view showing a process of separating paper by a conventional tip resistance method.

2 is a cross-sectional view showing another example of a conventional tip resistance method.

3 is a schematic structural diagram of an embodiment of an inkjet printer according to the present invention;

4 is a perspective view briefly showing a paper conveying system of the embodiment shown in FIG.

5 is a view showing in detail the first gear train;

6 is a detailed view of a second gear train;

7 is a view showing in detail the third gear train;

8 is a view showing the inclination angle of the tip resistance member.

9 is a perspective view showing an example of an angle conversion unit for converting the inclination angle of the tip resistance member.

10 is a flowchart of an embodiment of a paper conveying method of an inkjet printer according to the present invention.

<Description of Symbols for Main Parts of Drawings>

70 ...... Current detector 80 ...... Encoder

90 ...... Control section 110 ...... Cassette

120 ...... Pick-up roller 130 ...... Drive roller

140 ...... Feedroller 150 ...... Print head

151 ...... carrier 170 ......

180 ...... Drive motor 410 ...... Rotating member

420 ...... Sliding member 430 ...... Support member

Claims (11)

A pickup roller for picking up paper from a cassette on which paper is loaded, a leading resistance member contacting the leading end of the paper so that the paper on the uppermost side of the stacked paper is separated by rigidity and picked up from the cassette, and the paper is transported. In an inkjet printer comprising a feed roller to make, An angle conversion unit for converting an inclination angle of the tip resistance member with respect to the paper tip; A switching gear moved to a first position for driving the pickup roller and a second position for driving the angle conversion unit; And a carriage having a first moving section reciprocated for printing and a second moving section for moving the switching gear to the first and second positions. The switching gear is elastically biased in the direction to move to the first position, when the carriage is located in the first moving section is located in the first position, when the carriage moves to the second moving section An inkjet printer, which is pushed by a carriage and moved to the second position. The method of claim 1, And the switching gear is installed at one end of the feed roller so as to slide in the first position and the second position. delete The method according to claim 1 or 2, The angle conversion unit, A rotating member having a gear part connected to the switching gear and a screw part coaxially formed with the gear part; A sliding member having an inclined portion and connected to the screw portion to linearly move; A support member provided with the tip resistance member and rotated in contact with the inclined portion; And an elastic member elastically biasing the support member in a direction in contact with the inclined portion. A cassette in which paper is loaded, a leading resistance member for separating the paper loaded on the uppermost side of the loaded paper by the rigidity of the paper, an angle conversion unit for converting the inclination angle with respect to the edge of the paper of the leading resistance member, and driving In a paper conveying method of a printer having a feed roller and a pickup roller driven by a motor, and an encoder for generating a count proportional to the rotation amount of the feed roller and the pickup roller, A pickup step of rotating the pickup roller to pick up paper from the cassette; A retrying step of performing the pick-up step again after converting the inclination angle of the tip resistance member by driving the angle conversion unit when the tip of the picked-up paper is not detected by the first paper detector within a set time; Paper conveyance method of the inkjet printer comprising a. The method of claim 5, In the pick-up step, when the current limiting error exceeds the set threshold current amount and / or a counting error of the encoder exceeds a set reference interval, the angle conversion unit is driven to operate the angle conversion unit. And performing the pick-up step again after converting the inclination angle of the tip resistance member. The method according to claim 5 or 6, And the inclination angle of the tip resistance member after the conversion is larger than the original inclination angle. The method according to claim 5 or 6, And the angle conversion unit is driven by the drive motor. The method of claim 8, The retry step, Selectively moving the switching gear rotated by the driving motor to a first position for driving the pickup roller and a second position for driving the angle conversion unit by moving the carrier; And converting the inclination angle by the angle converting unit. The method of claim 9, Converting the inclination angle of the tip resistance member, Converting the inclination angle of the tip resistance member into a maximum or minimum inclination angle; Converting the difference between the maximum or minimum tilt angle and the tilt angle to be converted into a counting amount of the encoder; And driving the angle conversion unit until the counting amount of the encoder becomes the converted counting amount. The method according to claim 5 or 6, Before performing the first pick-up step, converting the inclination angle of the tip resistance member into an inclination angle suitable for the paper according to the paper information transmitted from the printer drive of the host computer. How do I transfer paper from an inkjet printer?