KR20040032380A - Inkjet printer being capable of borderless printing - Google Patents

Abstract

PURPOSE: An ink jet printer capable of borderless printing is provided to prevent a rear side of paper from being stained, by collecting ink discharged from a nozzle, being out of edges of paper. CONSTITUTION: A recording head(141) reciprocates in a horizontal scanning direction over a recording medium transferred in a vertical scanning direction to discharge ink. A plurality of collecting units(160) is installed under the recording head in the horizontal scanning direction for collecting the discharged ink. A plurality of wheel members(170) is installed at the collecting units for being rotated by being point-contacted with a rear surface of the recording medium. A cleaning pad removes the ink smeared to the plurality of wheel members.

Description

Inkjet printer being capable of borderless printing

The present invention relates to an inkjet printer, and more particularly, to an inkjet printer capable of printing borderlessly up to four edges of paper.

In general, an inkjet printer ejects ink from a recording head reciprocated in a direction perpendicular to a paper conveying direction (hereinafter referred to as a sub-scanning direction) and spaced apart from the upper surface of the paper by a predetermined interval (hereinafter referred to as a main scanning direction). Refers to an apparatus for forming an image.

1 is a schematic view showing a conventional inkjet printer.

As shown in the drawing, the inkjet printer has a paper feed cassette 10 loaded with paper P, a feed roller 20 for conveying paper P, and a direction perpendicular to the conveying direction of paper P on the upper surface of the paper P. Support for guiding the back surface of the paper P between the recording head 30 reciprocating in the direction, the discharge roller 40 for discharging the printed paper P, and the feed roller 20 and the discharge roller 40. And a member 50.

With this configuration, the paper P is taken out from the paper feed cassette 10, and the feed roller 20 is engaged with the idle roller 21 to rotate the paper P at a predetermined speed. When the tip of the paper P reaches the lower side of the recording head 30 while being supported by the support member 50, ink droplets corresponding to the image information are ejected from the recording head 30 onto the upper surface of the paper P. An image is formed. The printed paper P is discharged by the star roller 41 which is in point contact with the upper surface of the paper P while rotating in engagement with the discharge roller 40 and the printing is completed.

By the way, as shown in FIG. 2, in general, an inkjet printer does not form an image on the entire sheet of paper P, but rather a constant margin (a, b) at both ends of the width direction of the sheet of paper P, the leading end portion and the end portion of the paper sheet P in the longitudinal direction. (c, d) and print. This is because even though the length and width of the paper P are predetermined standard paper P, the width and length of the paper P may vary slightly depending on the manufacturer of the paper P. This is because the distal end and the distal end cannot be detected accurately.

Therefore, when printing without margins (a, b, c, d) in the inkjet printer as shown in FIG. 1, the ink ejected from the recording head 30 is formed at the leading end or at the end of the paper P or at both ends in the width direction. Can be buried in the support member 50 for guiding the back surface of the paper P. Then, the back surface of the paper P to be subsequently printed may be contaminated by ink deposited on the support member 50. In addition, when the paper P having a contaminated back surface is discharged and first printed and loaded on the upper surface of the discharged paper P, the printed image may be contaminated.

In addition, when the paper P is conveyed by the feed roller 20, a skew phenomenon may occur in which the paper P is inclined to the left and right instead of being straight. Therefore, even if the width and length of the paper P are made exactly as specified in the specification, when printing without the margins (a, b, c, d), the ink ejected from the recording head 30 leaves the paper P and the paper If the support member 50 for guiding the back of (P) may be buried.

However, in recent years, as inkjet printing is widely used for printing graphic images such as photographs, there is an increasing need for an inkjet printer capable of borderless printing that prints without margins of top, bottom, left, and right sides of paper.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described needs, and an object thereof is to provide an inkjet printter capable of borderless printing by collecting ink ejected beyond the edge of the paper so that the paper is not contaminated in subsequent printing.

1 is a schematic view showing a conventional inkjet printer.

2 shows a printable area by a conventional inkjet printer.

3 is an exploded perspective view showing a first embodiment of an inkjet printer according to the present invention;

4 is a perspective view showing another installation example of the fin member.

5 and 6 are a cross-sectional view taken along line A-A 'and B-B' of FIG. 3, respectively.

7 is a sectional view showing a modification of the cleaning means.

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

111 ............ Feed cassette 112 .........

121 ...... Feed Roller 122 ...... Pressure Roller

131 ...... Discharge Roller 132 ...... Star Wheel

141 ...... Recording head 147 ...... Nozzle section

150 ...... Second Frame 160 ......

161 ...... Absorption pad 170 ...... Wheel member

171 Cleaning pad 180 ... Rib

190 ...... Feeding motor 210 ...... Cleaning roller

211 ... cleaning blade 212 ... absorption pad

An inkjet printer of the present invention for achieving the above object comprises: a recording head for discharging ink while reciprocating in a main scanning direction from above a recording medium conveyed in a sub scanning direction; A collecting part provided below the recording head in a main scanning direction to collect ink discharged out of the recording medium; A plurality of wheel members installed at a plurality of places in the main scanning direction in the collecting unit and rotating in point contact with the rear surface of the recording medium; And cleaning means for removing ink from the wheel member.

Where the wheel member of the collection unit is not installed, it is preferable that an absorption pad for absorbing ink is provided.

The plurality of wheel members may be installed on a rotating shaft disposed in the main scanning direction, and the wheel members may be installed in at least two rows in the sub scanning direction.

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

3 is an exploded perspective view showing a first embodiment of the inkjet printer according to the present invention, and FIGS. 5 and 6 show cross-sectional views A-A 'and B-B', respectively, of FIG.

3, 5, and 6, the paper feeding unit 110 for supplying paper, the recording head 141 reciprocating in the main scanning direction, the conveying unit 120 for transporting paper, and the recording head 141 The second frame 150 for supporting the paper to be conveyed in the sub-scanning direction from below, and the discharge unit 130 for discharging the paper on which the image is printed.

The recording head 141 is mounted on the carrier 142. The carrier 142 is slidably coupled to the guide shaft 144 installed in the main scanning direction in the first frame 143, and is connected to the belt 146 reciprocating by the driving motor 145. As the drive motor 145 rotates forward and backward, the recording head 141 is reciprocated in the main scanning direction while being mounted on the carrier 142. Under the recording head 141, a nozzle portion 147 having a plurality of discharge ports for discharging ink is formed.

The paper feeding unit 110 includes a paper feed cassette 111 on which paper is loaded, and a pickup roller 112 installed on the loaded paper. The paper is withdrawn from the paper feed cassette 111 by the pickup roller 112 and sent to the transfer unit 120.

The feeder 120 includes a feed roller 121 and a pressure roller 122 in contact with an outer circumference of the feed roller 121 while applying a predetermined pressure. As shown in FIG. 3, the pressure roller 122 may be provided in plural in the main scanning direction. When the feed roller 121 is rotated by the feed motor 190, the plurality of pressure rollers 122 are driven by the frictional force with the feed roller 121.

A plurality of ribs 180 protruding at a predetermined height and extending in the sub-scanning direction are arranged on the upper surface of the second frame 150 in the main-scanning direction. The rib 180 guides the back surface of the paper so that the paper as the gap holding member can be conveyed while maintaining a predetermined vertical gap with the nozzle unit 147.

The collecting part 160 is provided below the nozzle part 147. The collecting unit 160 is a place where the ink out of the paper falls out of the ink discharged from the nozzle unit 147, and as shown in FIGS. 5 and 6, the collecting unit 160 moves downward from the upper surface of the second frame 150. It is immersed and formed. The length L1 of the main scanning direction of the collecting unit 160 is preferably larger than the width of the paper used, and the length L2 of the subscanning direction is larger than the length L3 of the subscanning direction of the nozzle unit 147. It is preferable.

A plurality of wheel members 170 are installed in the collecting unit 160 so as to be rotated in the sub scanning direction by being spaced apart at predetermined intervals in the main scanning direction. The installation interval and the number of the wheel members 170 may be appropriately determined in consideration of the width of the paper used. The wheel member 170 is a sawtooth-shaped rotating body in which mountains and valleys are repeatedly arranged on the outer circumference thereof, and is in point contact with the rear surface of the paper to be conveyed. The wheel member 170 is preferably installed such that its upper vertex is positioned at or slightly lower than the upper surface of the rib 180, which is a gap holding member. The plurality of wheel members 170 may be installed to rotate independently of each other. In this case, the fin member 170 is rotated by the contact force while being in contact with the back surface of the paper to be conveyed. In addition, as shown in Figure 4 may be coupled to the rotary shaft 172 provided in the main scanning direction may be rotated together with the rotary shaft 172. In this case, the wheel member 170 may be rotated by a contact force with the paper, but more preferably, the wheel member 170 is rotated by the feeding motor 190 that is power-connected to the rotary shaft 172. Although not shown in the drawings, the wheel member 170 may be provided with two or more rows in the sub-scanning direction. This is because when the recording head 141 having a long sub-scan direction of the nozzle unit 147 is used, the length of the sub-scan direction of the collecting unit 160 also becomes long. In this case, only one row of wheel members 170 It may be difficult to guide wet paper so that it does not sag down.

As shown in FIG. 6, the collecting unit 160 is preferably provided with an absorbent pad 161 for absorbing the dropped ink except where the wheel member 170 is installed. The absorbent pad 161 is preferably installed such that its upper surface is lower than the upper surface of the rib 180 so that ink does not adhere to the back surface of the paper.

The cleaning pad 171 may be installed below the wheel member 170 as shown in FIGS. 5 and 6 as cleaning means for removing ink from the wheel member 170. Because the wheel member 170 is usually produced by injection molding plastic or by combining a plate having a tooth-shaped plate and a body having a rotating shaft, because ink is not absorbed by the wheel member 170 and flows downward by gravity. to be.

The discharge unit 130 includes a discharge roller 131 in contact with the back surface of the paper, and a star wheel 132 that is driven by being engaged with the discharge roller 131. The star wheel 132, which is in point contact with the upper surface of the printed sheet, is a rotary body having a sawtooth outer circumference like the wheel member 170.

5 and 6, the operational effects of the first embodiment of the inkjet printer according to the present invention shown in FIG. 3 will be described.

The paper taken out from the paper feed cassette 111 by the pickup roller 112 is drawn between the feed roller 121 and the pressure roller 122 and is conveyed below the recording head 141. When the leading end of the paper is drawn below the nozzle unit 174, that is, above the collecting unit 160, the wheel member 170 is rotated with the conveyance of the paper while being in point contact with the back surface of the paper. The nozzle unit 174 discharges ink on the paper to start printing an image, and performs borderless printing up to the end of the paper as the paper is transferred. The printed paper is discharged by the discharge roller 131 and the star wheel 132. At this time, the ink deviating from the leading edge, the distal end, and the edges in the sub-scanning direction of the paper falls to the collecting portion 160 and the wheel member 170. Ink dropped on the collecting unit 160 is absorbed by the absorption pad 161, and ink dropped on the wheel member 170 flows down to the cleaning pad 171 as the wheel member 170 is rotated and removed. Since the upper surface of the absorbent pad 161 is lower than the rib 180 which is the gap holding member, and the ink dropped on the wheel member 170 is removed by the cleaning pad 171, the back surface of the paper is formed by the ink even when borderless printing is performed. No contamination occurs. Paper wetted by ink tends to be drooped down from the collecting unit 160. In this case, the gap between the upper surface of the paper and the nozzle unit 147 may be farther away, resulting in a problem of deterioration in print quality. A jam may occur when the leading end of the paper is caught on the exit side of the 160. However, according to the inkjet printer according to the present invention, the wheel member 170 installed in the collecting unit 160 supports the rear surface of the paper, so that the gap between the upper surface of the paper and the nozzle unit 147 is maintained such a problem occurs. It doesn't work. In addition, it is necessary to go through a special printing process such as a shingling algorithm that sequentially ejects ink from some of the nozzles of the nozzle part while transferring the paper in several steps when printing the leading end and the end of the paper. As a result, the problem of slow printing speed does not occur.

The cleaning means for removing the ink on the wheel member 170 can be modified in various ways. 7 is a sectional view showing a modification of the cleaning means.

Referring to FIG. 7, the cleaning roller 210 contacts and rotates the wheel member 170 as a roller-shaped cleaning means to wipe off the ink on the wheel member 170. The cleaning roller 210 may be rotated using a separate motor, but is more preferably connected to the feeding motor 190.

The plurality of wheel members 170 may be installed to be rotated independently of each other, may be coupled to the rotary shaft 172 installed in the main scanning direction as shown in Figure 4 may be rotated together with the rotary shaft 172. At this time, the wheel member 170 is preferably driven to rotate as the cleaning roller is rotated by the contact force with the cleaning roller 210, it is also possible to be power-connected with the feeding motor 190.

The cleaning blade 211 may be installed on the outer circumference of the cleaning roller 210. The cleaning blade 211 prevents the ink on the cleaning roller 210 from contaminating the wheel member 170 by scraping off the ink on the cleaning roller 210. In addition, the cleaning means may further include a cleaning pad 212 for absorbing ink scraped off by the cleaning blade 211 and ink flowing down from the wheel member 170. The cleaning pad 212 is preferably installed below the wheel member 170 so as to absorb the ink flowing away from the wheel member 170. The effect by such a configuration is the same as that described with respect to Figure 3, so repeated description is omitted.

As described above, according to the inkjet printer according to the present invention, the following effects can be obtained.

First, since the ink out of the paper can be collected from the collecting unit to prevent the back surface of the paper from being contaminated, borderless printing is possible without printing with four margins.

Second, by providing the wheel member to support the back side of the paper at the collecting portion, it is possible to prevent the wet paper from sagging down by the ink. Therefore, the distance between the paper and the nozzle portion is kept constant, so that a print image of good quality can be obtained.

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.

Claims (13)

A recording head for discharging ink while reciprocating in the main scanning direction from above the recording medium conveyed in the sub-scanning direction; A collecting part provided below the recording head in a main scanning direction to collect ink discharged out of the recording medium; A plurality of wheel members installed at a plurality of places in the main scanning direction in the collecting unit and rotating in point contact with the rear surface of the recording medium; And cleaning means for removing ink adhering to the wheel member. The method of claim 1, And an absorption pad installed at a place where the wheel member of the collecting unit is not installed to absorb ink. The method of claim 1, And at least two rows of the wheel members in a sub-scanning direction. The method of claim 3, An inkjet printer, characterized in that the wheel members of different rows are alternately installed in the main scanning direction. The method according to any one of claims 1 to 4, The recording medium is maintained between the recording head and the recording medium by a gap holding member supporting the rear surface thereof. And the wheel member is provided so as not to protrude toward the recording head than the gap holding member. The method according to any one of claims 1 to 4, The cleaning means, And a cleaning pad installed under the wheel member to absorb ink. The method of claim 6, The plurality of wheel members are installed independently of each other, the inkjet printer, characterized in that rotated by the contact force with the paper. The method according to any one of claims 1 to 4, The cleaning means, And a cleaning roller which rotates in contact with the wheel member to wipe off the ink adhered to the wheel member. The method of claim 8, And the plurality of wheel members are independently installed and driven as the cleaning roller is rotated. The method of claim 8, The plurality of wheel members are installed in combination with the rotating shaft installed in the main scanning direction inkjet printer. The method of claim 10, And the plurality of wheel members are driven as the cleaning roller is rotated. The method of claim 8, And the cleaning means further comprises a cleaning blade which contacts the cleaning roller and removes the ink deposited on the cleaning roller. The method of claim 8, And a cleaning pad installed under the wheel member to absorb ink.