KR100422014B1 - An inclined paper-transfer type printer - Google Patents

Abstract

According to the present invention, an inclined paper-type inkjet printer has a print medium perpendicular to any side of the outline of the print medium when the print medium is moved relative to the head and ink ejected from the head is sprayed onto the print medium surface to be printed. It is configured to feed in a direction that is not horizontal. According to the present invention, the printing medium is fed in a direction that is not vertical or horizontal with any side of the outline of the printing medium, so that only one nozzle is used instead of one nozzle during printing, in particular, when printing vertical lines, the printing is performed by sharing several nozzles. It is possible to prevent the performance degradation of the nozzles caused by ink drying caused by not being used for a long time during printing, and to improve the stability of printing quality.

Description

Incline feed inkjet printers {An inclined paper-transfer type printer}

The present invention relates to an inkjet printer, and more particularly, to an inclined paper type inkjet printer which obtains stable printing quality by feeding a print medium such as a recording paper used in an inkjet printer in a direction having a constant angle with the outline of the print medium. will be.

In general, an inkjet printer is a device that prints desired characters, figures, images, etc. by spraying ink droplets on a print medium to a desired position, and is widely used for office or personal use that emphasizes compactness. The inkjet printer is divided into a piezoelectric type for pressurizing an ink chamber using a piezoelectric element and a thermal type for forming bubbles by using heat generated by a heat generating element according to a method of discharging ink droplets.

The inkjet head, which constitutes an essential part of the inkjet printer, is a component that ejects ink according to a signal given from a main body, and a plurality of nozzles through which ink is ejected are integrated, making it difficult to produce a certain size or more. Therefore, at present, when the print medium moves in the longitudinal direction, the head moves in the width direction and passes over the printing surface of the print medium to discharge ink to print. However, as head manufacturing technology is gradually developed, attempts have been made to apply line heads to products that enable the production of heads that are as wide as the print media. By using the line head, only the print medium is moved in one direction from the line head while the head is not moved, and thus printing is possible on the entire surface of the print medium. Application of the line head has the advantage that the printer can be simplified by relatively eliminating the moving mechanism of the head, and the landing point of the ink drop is more accurate.

Referring to FIG. 1, a printing pattern of a line head 10 of a general thermal inkjet printer is schematically illustrated.

The line head 10 of a typical thermal inkjet printer has more than a few hundred nozzles 1a-n per inch, depending on the design. The nozzles 1a-n may be constituted by one line like the line head 10 shown in FIG. 1, or may be two or more lines in some cases, such as the line heads 10 'and 10 "shown in FIGS. 2A and 2B. Arranged alternately in a row so as to obtain the degree of integration between nozzles, i.e., nozzle spacing b, substantially necessary for printing. Of the dot array or pixels 12 of the corresponding rectangular shape of the print medium 11 through the heating element (not shown) and the nozzles 1a-n according to the printing signal when the paper is fed at a period of the pitch P. Printing is performed by spraying ink on the pattern.

However, the conventional inkjet printer using such a line head 10, as shown in Figure 1, is printed when printing a vertical line parallel to the direction in which the print medium 11, which frequently appears when using the actual printer proceeds Line 13 continues to be printed by ink droplets ejected from one nozzle 1a. The nozzles 1a-n of the line head 10 are very sensitive components, and the discharge may be uneven or may be temporarily impossible depending on the situation. Therefore, when printing the vertical line 13 with one nozzle 1a, if the state of the corresponding nozzle 1a is bad, it will have a fatal effect on image quality. In particular, when printing a black side, it appears as a long white line, and it is immediately noticeable. In addition, since only the nozzle 1a which is frequently used is intensively used, nozzles that are not well written have a problem that ink droplets are hardened or deposited, which may cause a decrease in nozzle performance and thus print performance.

The present invention has been made in view of the above problems, and an object of the present invention is to feed a print medium in a direction having a predetermined angle with the outline of the print medium so that neighboring pixels in the print pattern can be printed by different nozzles if possible. The present invention provides an inclined paper feed inkjet printer which improves print quality and prevents nozzle performance deterioration.

1 is a conceptual diagram of a printing pattern of a line head of a conventional inkjet printer.

2A and 2B are partial plan views for illustrating the nozzle arrangement of the linehead.

3 is a conceptual diagram of a printing pattern of a line head of an inkjet printer in accordance with the present invention.

4 is a conceptual diagram of a print pattern of the line head of the inkjet printer of the present invention when the inclination angle of the print medium with respect to the feeding direction is 45 °.

5A, 5B and 5C are plan views illustrating the feeding direction of a print medium.

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

10, 100: head 11, 101: print medium

12, 102: cell 13, 103: vertical line

L, P: pitch b, b ': nozzle spacing

W, W ', W ": Width Y, Y', Y": Feeding direction

In order to achieve the above object of the present invention, the present invention is an inkjet printer equipped with a head for ejecting ink, the ink ejected from the head is sprayed on the surface of the print medium while the head and the print medium are moved relative to each other It is characterized in that the inclined paper-type inkjet printer configured to feed the print medium in a direction that is not perpendicular or horizontal to any side of the outline of the print medium.

In a preferred embodiment, the head consists of a line head whose width is equal to or greater than the width of the paper feed trajectory of the print medium.

In this embodiment, the angle formed by the side corresponding to the outline of the print medium and the paper feed direction may be configured to change to at least two or more angles when the print medium of one page is printed.

In addition, the angle formed by the sides and the paper feed direction corresponding to the outline of the print media may be various angles between the positive and negative angles in order to reduce the width of the paper feed trajectory and the line head. It can be configured to alternately. In this case, since the width of the paper feed trajectory and the width of the line head are not greatly increased, the absolute value of the angle formed by the print medium and the paper feed direction can be changed, so that the nozzles of each of the line heads can be used in combination. If the neighboring pixels of are possible, the shingling effect printed by other nozzles can be made larger.

Also, optionally, the angle formed by the side corresponding to the outline of the print medium and the paper feed direction may be configured to continuously change at least two or more angles when the print medium of one page is printed.

In addition, in the embodiment of the present invention, it is preferable that the print medium is configured such that the side corresponding to the vertical outline has an angle of −45 ° to + 45 ° with respect to the feeding direction. The printing medium is preferably composed of a recording paper in the form of a square, but may also be configured in the form of another recording medium or a continuous roll in the form of a square.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an inkjet printer of a preferred embodiment consistent with the present invention will be described with reference to the accompanying drawings.

First, referring to FIG. 3, a vertical outline of a printing medium 101 such as a recording sheet is placed and fed at a predetermined angle (θ °) with respect to the feeding direction Y of the printing medium 100. In this case, the printing pattern of the line head 100 of the inkjet printer consistent with the present invention is schematically shown.

The linehead 100 of the inkjet printer of the present invention has several hundred nozzles 1a-n per inch, depending on the design. The nozzles 1a-n are configured in one row as shown in FIG. 3, or alternately arranged in two or more rows as shown in FIGS. 2A and 2B, whereby the nozzle spacing b 'required for printing is substantially provided. Is configured to obtain. The line head 100 is fixed in the main body of the printer so as not to move. The line head 100 is a heating element (not shown) and the nozzle (1a-) according to the print signal when the print medium 101 moves in the period of the pitch (L) in the feed direction (Y) of the print medium 101 Printing is performed by spraying ink onto the corresponding dot array or pattern of the pixels 102 of the print medium 101 through n).

3 and 5A, in the inkjet printer of the present invention, the feeding direction Y of the print medium 101 is an angle that is not perpendicular or horizontal to any side of the outline of the print medium 101. As shown in FIG. Have

The angle θ ° of the print medium 101 with respect to the feeding direction Y is set to a specific angle between 0 ° and 45 °, and as the angle θ ° increases from 0 ° to 45 °, The width of the corresponding line head 100 is set wider. That is, the width of the line head 100 is the width W 'of the paper feed trajectory, which appears when the ends of both sides of the print medium 101 arranged inclined as shown in FIG. 5A travel in the paper feed direction Y. Greater than or equal to In this case, the width W 'is larger by a value corresponding to an inclination angle than the width W of the print medium 101.

When the distance between each cell, that is, the pitch L, corresponds to the horizontal or vertical resolution of the printed material on the printed material having the same horizontal resolution and vertical resolution, as shown in FIG. 3, the print medium 101 is fed in the feeding direction (Y). With a certain angle (θ °), the angle (when printing a vertical line 103 parallel to the vertical outline of the print medium 101, as in the conventional line head 10 described in connection with FIG. The number of times the same nozzle is taken continuously varies depending on θ °). That is, when the print medium 101 has a certain angle (θ °) with respect to the feeding direction Y, the nozzles 1a-n are once at the nozzle 1a, three times at the nozzle 1b, and the nozzle ( Ink drops are applied to the corresponding cells 102 in the order of 2 in 1c, 3 in the nozzle 1d, and the like.

In addition, as shown in FIG. 4, when θ ° is 45 °, the same nozzles are not taken continuously but each nozzle is taken once, but when θ ° is 26.54 °, the same nozzles are successively twice, and the same nozzle is used at 18.43 °. This is taken three times in a row. In fact, even with a small angle of 5.75 °, the same nozzle is taken 10 times in succession and the next pixels 102 are taken by the next nozzle.

Therefore, in the inkjet printer to which the concept of the printing pattern shown in FIGS. 3 and 4 is applied, when the θ ° is 5 ° to 10 °, the width W 'of the paper feed path of the print medium 101, that is, the line head ( It becomes an appropriate angle (θ °) from which the inclined paper feeding effect of the present invention, which allows neighboring pixels in a printing pattern to be printed by different nozzles without greatly increasing the width of 100).

3 and 4, each pixel 102 formed of a rectangle formed on the print medium 101 is virtually set to designate a nozzle corresponding to each point of the print medium 101 when printing with an inkjet printer. In fact, each ink drop has a very irregular radial or circular shape on the surface of the print medium when the ink drop ejected from the line head 100 is printed by touching the print medium 101. Therefore, the circular ink droplets ejected on the surface of the print media spread to neighboring pixels while sufficiently covering the virtual pixels, and a substantial portion of the overlapping pixels overlap with the neighboring pixels to form substantially continuous letters, lines, and the like. It becomes visible.

Depending on the printing condition, in the worst case, ink droplets may not be discharged from one particular nozzle. However, when inclined paper feeding using multiple neighboring nozzles as in the present invention, such printing defect may be hidden. For example, if a dot corresponding to three pixels at 1200 dpi (dot per inch) is not printed, the portion corresponding to 0.0635 mm (= 3 x 25.4 mm / 1200) is not printed, but ink printed on surrounding pixels Considering the bleeding of the droplets, it becomes a print defect that is hardly noticeable.

Referring to the case of printing the vertical line 103 parallel to the vertical outline of the printing paper 101 with respect to the operation of the printer of the present invention configured as described above, first, as the print signal is applied, the print medium 101 In the feeding direction (Y) of the print medium 101 by the predetermined feeding roller is moved in the period of the pitch (L), at the same time, the line head 100 is a heating element (not shown) in accordance with the printing signal and Printing is performed by spraying ink onto the pattern of the corresponding pixels 102 of the print medium 101 through the nozzles 1a-n.

In this case, the nozzles 1a-n correspond to the cells 102 in the order of the nozzle 1a, the nozzle 1b 3 times, the nozzle 1c 2 times, the nozzle 1d 3 times, and so on. Ink droplets are ejected into the. Each of the cells 102 in which the ink is ejected and ejected has a plurality of stepped shapes parallel to the vertical outline of the print medium 101 as indicated by hatching in FIG. Will form points. At this time, the plurality of stepped points are apparently seen as vertical lines 103 as indicated by the dotted lines. As such, the next nozzles 1e-n discharge the ink droplets until the required vertical line 103 is completely printed, thereby printing, and the printing medium 101 on which the printing is completed is discharged out of the printer by the paper feed roller. do.

In the above, the printer of the present invention, as shown in Figs. 3, 4 and 5a in a state in which the longitudinal direction of the print medium 101 is inclined at a specific angle with respect to the longitudinal direction of the line head 100. Although the paper feeding direction (Y) is perpendicular to the longitudinal direction of the line head 100 as in the conventional printer, it was described as being fed. However, as shown in FIG. 5B, the print medium 101 is placed on the line head 100. In the vertically arranged state, the paper feeding direction Y 'may be configured to be inclined at a specific angle with respect to the longitudinal direction of the line head 100. Also in this case, the feeding direction of the print medium 101 (Y ') has an angle that is not perpendicular or horizontal to any side of the outline of the print medium 101 as shown in FIG. 5B. The print pattern of the line head 100 according to the angle of the print medium 101 with respect to Y ', that is, the number of times taken by the same nozzle, is also displayed as described with respect to 5a.

At this time, the feeding direction (Y ') of the print medium 101 is to arrange the paper feed roller (not shown) for feeding the print medium 101 inclined at a predetermined angle with respect to the longitudinal direction of the line head 100. Can be adjusted.

The operation of the ink jet printer configured as described above is different from the operation of the printer described with reference to FIGS. 3, 4, and 5A, except that only the paper feeding direction (Y ′) is different.

In addition, the inkjet printer of the present invention, as shown in Figs. 5A and 5B, has one positive (+) angle, i.e., zero, of the angle (θ °) of the print medium 101 with respect to the paper feed direction (Y, Y '). It may be configured to increase or change at various angles between 0 ° and 45 ° without feeding in a fixed position at any one angle between ° and 45 °. In this case, the width of the corresponding line head 100 is configured to be as large as the maximum width W 'of the paper feed path of the print medium 101 when the angle θ ° of the print medium 101 is 45 °. do.

However, as shown in FIG. 5C, when the angle θ ° of the print medium 101 with respect to the paper feed direction is changed between a plus (+) angle and a minus (−) angle, the feed trajectory of the print medium 101 is changed. The width W ′ and thus the width of the print head 100 can be obtained without increasing the warp feeding effect of the present invention. For example, if the angle (θ °) of the print medium 101 with respect to the feeding direction is changed between + 45 ° and -45 ° every time 10 dots are taken in the longitudinal direction at 1200 dpi printing condition, Only 10 additional nozzles are needed compared to the linehead, and the linehead incremental width (W ") only needs to be 0.21mm (= 10 x 25.4mm / 1200) wider.

In addition, in order to further increase the single ring effect of improving printing quality by forming dots printed on neighboring pixels 102 with ink droplets from different nozzles 1a-n, the printing medium for the feeding direction ( It is better to combine various angles irregularly than to repeat the angle θ ° of 101) at regular angles regularly.

For example, in Table 1 below, combinations of irregular angles such as (I) and (C) show much better print quality than combinations such as (A).

(end) + 45 ° 10 lines → -45 ° 10 lines → + 45 ° 10 lines → -45 ° 10 lines → + 45 ° 10 lines → (I) + 45 ° 10 lines → -26.5 ° 14 lines → -18.4 ° 12 lines → -45 ° 5 lines → + 18.4 ° 9 lines → (All) + 18.4 ° 9 lines → 0 ° 5 lines → + 26.5 ° 10 lines → 18.4 ° 6 lines → 0 ° 7 lines →

In the case of (b), when printing vertical lines in the longitudinal direction of the print medium 101, the first 10 pixels are printed by different nozzles, and then the 14 pixels are printed by the same nozzles only two by one. The next 12 pixels are printed by the same nozzle three by three. Therefore, even if there is an abnormality in a particular nozzle and a printing defect occurs, such a defect occurs irregularly. Such irregular printing defects have the advantage of being less noticeable than regular printing defects.

In consideration of the feeding speed of the print medium 101, it is very difficult to accurately distinguish and change the angles θ ° shown in Table 1 above. Therefore, it is easier to implement substantially continuously changing the angle [theta] [deg.] Of the print medium 101 with respect to the paper feeding direction. That is, by increasing the angle (θ °) of the print medium 101 with respect to the feeding direction in the positive (+) direction, decreasing it again, increasing the negative angle in the negative (-) direction, and then decreasing it again. An angle θ ° of the print medium 101 relative to the print medium 101 may be adjusted. As a result, the print medium 101 is fed in a form that passes under the line head 100 while shaking from side to side. Also, optionally, the singling effect can be increased by irregularizing the speed of increasing or decreasing the angle [theta] [deg.] Of the print medium 101 with respect to the feeding direction.

At this time, the adjustment of the angle (θ °) of the print medium 101 with respect to the feed direction during printing of the print medium 101, that is, the adjustment of the feed direction Y ″ may be performed by a separate It can be adjusted by installing a paper feeder.

As such, the angle (θ °) of the print medium 101 with respect to the feeding direction is increased or changed by various angles between 0 ° and 45 °, or continuously changed between a positive (+) angle and a negative (-) angle. The action of the printer of the present invention is that the paper feeding direction (Y ") changes compared to the operation of the printer described with reference to Figs. The basic operation is the same except that it changes for each angle (θ °) of the print medium 101 at the point of time.

As described above, in the inkjet printer of the present invention, even if one vertical line is printed, the printed line is not continuously printed by ink droplets ejected from the same nozzle, but the nozzles around the ink are evenly distributed and printed. As in this case, it is possible to prevent the clogging or abnormality of the nozzles caused by not using it for a long time during printing, thereby stabilizing the printing quality. Also, even if some nozzles are abnormal, the overall image quality is prevented from falling rapidly. This has the effect of preventing the problem of having to replace the entire head.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiment, and various modifications and variations can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. Will be possible.

Claims (10)

An inkjet printer equipped with a head having a plurality of nozzles for ejecting ink. A print medium for printing data may be used with any side of an outline of the print medium so as to evenly use the plurality of nozzles when ink ejected through the plurality of nozzles of the head is sprayed onto the surface of the print medium and printed. Feeding with a feeding direction that changes at least two arbitrary angles that are not vertical or horizontal; And the head comprises a line head having a width of the head wider than or equal to a width of a paper feed trajectory of the printing medium and not moving in at least the width direction of the head. delete delete The inkjet printer of claim 1, wherein the angle comprises a plurality of angles between a positive (+) angle and a negative (-) angle that alternately change when a print medium of one page is printed. The inkjet printer of claim 1, wherein the angle comprises at least two or more angles that change continuously when a print medium of one page is printed. The inkjet printer of claim 1, wherein the print medium is disposed such that a side corresponding to a vertical outline of the print medium has an angle that is not perpendicular to the width direction of the head. The inkjet printer of claim 1, wherein the angle has an angle between −45 ° and + 45 ° with respect to a side corresponding to a vertical outline of the print medium. The inkjet printer of claim 1, wherein the print medium has a quadrangular shape. 7. The inkjet printer of claim 6, wherein the print medium is comprised of recording paper. The inclined paper feeding inkjet printer of claim 1, wherein the print medium is formed in a continuous roll form.