JP4100441B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to a recording apparatus that prints characters and patterns on a recording medium by ejecting ink droplets from nozzle openings.

An ink jet recording apparatus prints characters and patterns by reciprocating an ink jet recording head having a plurality of nozzle openings in a paper width direction of a recording medium such as recording paper by a carriage. Since it can be made small and dots can be formed at a high density with a relatively simple structure, there is a feature that a recording apparatus with high printing quality can be provided at low cost.
However, as the dot density increases, the number of dots to be printed on one page increases dramatically, and there is a problem that the time required to print one page increases.

In order to solve such a problem, a page recording apparatus that uses a so-called line head in which about 2,000 nozzle openings are arranged in an area covering the width of the recording medium and performs printing only by feeding recording paper has been proposed. However, since the numerical aperture of the same recording head is increased, the manufacturing yield is extremely reduced, and a precise medium feeding mechanism in units of one dot is required, resulting in an increase in cost.
Furthermore, since the same position is printed with the same nozzle opening, if the ink droplets ejected from each nozzle opening have uneven ink amount and bending in the flight direction, uneven printing will occur locally. Therefore, there is a problem that the printing quality as a whole is lowered.
The present invention has been made in view of such a problem, and an object of the present invention is to simplify the recording head and the medium feeding mechanism, and to perform uniform recording without unevenness at high density and high speed. It is an object to provide an ink jet recording apparatus that can perform printing.

  In order to solve such a problem, in the present invention, a nozzle opening row having M nozzle openings at a pitch of 2P dots (where P is an integer of 2 or more) in the recording medium feeding direction, The recording is performed at a pitch of a plurality of dots K (where K is an integer equal to or greater than 2) in the width direction of the recording medium and staggered by one dot in the recording medium feed direction between adjacent nozzle opening rows. An ink jet recording head arranged to cover the width of the medium, a carriage for reciprocating the ink jet recording head by (2K-1) dots, and the recording medium when printing in one direction is completed And a medium feeding mechanism for feeding the recording medium by M × 2 dots when printing in the other direction is completed.

  According to the present invention, while improving the speed by a large number of nozzles, the advantage of printing by the serial method, that is, avoiding the formation of print lines in the paper feed direction and the printhead feed direction with the same nozzle opening, is avoided. The ink amount of the ink droplets from the nozzle openings and the flight curve can be dispersed to eliminate the bias, and the overall print quality can be improved.

Therefore, details of the present invention will be described below based on the illustrated embodiment.
FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a carriage, which has a length approximately equal to the width of the recording medium 2 and is supported by guide members 3 and 3, and a carriage drive circuit. 10 is configured to reciprocate with an amplitude (2K-1) in the width direction of the recording medium 2 indicated by an arrow AA ′ in the figure by a drive mechanism 4 controlled by 10, and will be described later on a surface facing the recording medium 2. The recording head 5 is fixed.

  Reference numeral 6 denotes a recording medium feed mechanism, which is controlled by a motor 7 controlled by a feed mechanism drive circuit 11 and has nozzle openings constituting a nozzle opening row which will be described later on the recording medium 2 in accordance with the moving direction of the recording head 5 as will be described later. Sending twice as many as several M.

  A print control unit 12 receives a print signal from an external device, moves the carriage 1 in one direction, operates the recording head 5 by the head drive circuit 12 to discharge ink droplets, and prints in one direction. At the stage of completion, the recording medium feed mechanism 6 feeds the recording medium 2 by twice the number of nozzle openings M of the nozzle opening row of the recording head 5, and the carriage at the stage of completion of printing in one direction. Printing is performed by ejecting ink droplets from the recording head 5 while moving 1 in the other direction, and when the printing is completed, the second printing process for feeding the recording medium 2 by M × 2 is performed for one page. Are executed alternately.

  FIG. 2 shows an embodiment of the above-described recording head in the form of an array of nozzle openings. In the figure, reference numerals N1, N2, N3,. A plurality of nozzle openings 1-1, 1-2, 1-3 ... 1-63, 2-1, 2-2, 2-3 ... 2-63, n-1, n-2, n-3... n-63 is substantially recorded at a constant pitch P (where P is a plurality of integers, and in this embodiment, 4 dots are selected so that the recording density of each nozzle aperture row is 90 dpi). It is arranged in a region L that can cover the width of the medium 2.

  Each nozzle opening row N1, N2, N3... Nn-1, Nn has an odd row (N1, Nn) with a distance of K dots (where K is an integer of 2 or more) in the width direction of the recording medium 2. N3, N5... And the even-numbered rows (N2, N4, N6...) And the recording medium feed direction (vertical direction in the figure) are shifted by Δd (in this embodiment, the printing density is 360 dpi as a whole. 1 dot, that is, 1/360 inch) is set so that printing is possible.

  By the way, these nozzle openings 1-1, 1-2, 1-3 ... 1-63, 2-1, 2-2, 2-3 ... 2-63, n-1, n-2, n-3 As is well known, n-63 communicates with a pressure generating chamber that receives ink supply from a common ink chamber, and corresponds to a printing signal applied to a piezoelectric vibrator, a Joule heat generating element, or the like. Drops are ejected.

  Next, the operation of the apparatus configured as described above is such that the nozzle opening pitch P in the recording medium direction is 4 dots, and the nozzle opening number M of the nozzle opening row is 15 dots, that is, the printing height H is 4 × 15 + 1 = 57 dots. Further, an ink jet recording head having a 4-dot pitch K between nozzle rows will be described as an example with reference to FIGS.

(First printing process)
When the print control means 12 moves the carriage 1 in one direction and outputs print data to the recording head 5, the odd columns N1, N3, N5,. , And even-numbered nozzle opening rows N2, N4, N6,... Form dots on the second, sixth, tenth, fourteenth,..., 54, and 58 lines, respectively (circle frame 1 in FIG. 3).

  In this way, the scanning advances and the nozzle openings of the odd-numbered rows N1, N3, N5... Are one dot before the nozzle opening rows of the odd-numbered rows N3, N5, N7... Adjacent in the scanning direction (right side in the figure). In addition, when the printing is completed up to one dot before the even-numbered nozzle openings adjacent to the even-numbered nozzle openings, that is, at the stage where scanning of 2 (K-1) dots is completed, the medium feeding mechanism 7 The medium is fed out from the recording medium 2 by twice (M × 2 = 30) dots of the nozzle numerical aperture of one row of the recording head 5 (circle frame 2 in FIG. 3). As a result, the nozzle openings 1-1, 3-1,..., N-1 at the upper end of the recording head 5 are positioned at the center of the printed area on the 31st line.

(Second printing process)
At the stage when the recording medium feeding is completed, the print control means 12 moves the carriage 1 in the other direction, while the odd-numbered nozzle opening rows N1, N3, N5. , 91 lines and the 32nd, 36th, 40th,... 84, 88, 92th lines are printed by the nozzle opening rows N2, N4, N6.

  By this printing process, lines are printed in a region that is printed in the first printing process and has an interval of two lines, and dots are printed at a predetermined pitch.

  When printing is completed to the original position in this way, the recording medium 2 is fed by M × 2 dots, that is, 30 dots (circle frame 4 in FIG. 3).

  By this medium feeding, the nozzle openings 1-1, 3-1,..., N-1 at the upper end of the recording head 5 are positioned on the 61st line, so that the first printing process and the second printing process are performed again. One page can be printed by repeating.

  In the above embodiment, for convenience of explanation, dots in the upper end, both sides, and a part of the lower end are also shown. However, in actual printing, the first to 28th lines are interlaced as shown in FIG. As can be seen from the printing method, it is obvious that the print data is output so that ink droplets are not ejected in these regions, and the 29th line and subsequent lines indicated by region E may be used as actual print regions.

It is a block diagram which shows one Example of this invention. It is a front view which shows one Example of the inkjet recording head used for an apparatus same as the above. It is a figure which shows the movement of the inkjet recording head of the apparatus same as the above, and feeding of a recording medium. It is a figure which shows the printing state of an apparatus same as the above.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Carriage 2 Recording medium 4 Carriage drive mechanism 5 Inkjet recording head 6 Recording medium feed mechanism 1-1-n-63 Nozzle opening N-1-N-63 Nozzle opening row H Printing height of nozzle opening row K Nozzle opening row Arrangement pitch in the scanning direction P Nozzle opening pitch

Claims (2)

A nozzle opening array having a pitch of 2P dots (where P is an integer of 2 or more) in the feeding direction of the recording medium and having M nozzle openings is arranged in a plurality of dots K (where K is 2) and arranged so as to cover the width of the recording medium by alternately shifting the recording medium in a zigzag pattern by one dot in the direction opposite to the feeding direction of the recording medium between adjacent nozzle opening rows. An inkjet recording head,
A carriage that reciprocates the ink jet recording head by (2K-1) dots;
When the printing in one direction is finished, the recording medium is fed by M × 2 dots, and when the printing in the other direction is finished, the recording medium is fed by M × 2 dots. Mechanism,
An ink jet recording apparatus comprising:   The inkjet recording apparatus according to claim 1, wherein the 2P is 4.

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