Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/135—Nozzles
  • B41J2/145—Arrangement thereof
  • B41J2/15—Arrangement thereof for serial printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J19/00—Character- or line-spacing mechanisms
  • B41J19/14—Character- or line-spacing mechanisms with means for effecting line or character spacing in either direction
  • B41J19/142—Character- or line-spacing mechanisms with means for effecting line or character spacing in either direction with a reciprocating print head printing in both directions across the paper width
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/21—Ink jet for multi-colour printing
  • B41J2/2132—Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding

Definitions

• the present invention relates to computerized printing, and particularly to the operation of ink-jets printing heads.
• a printing head as denoted H in Fig. 1 a comprises a series of tiny ink- emitting nozzles N, and a computer programmed mechanism for controlling the timing of each and every one of the nozzles according to the pattern to be printed.
• the printed pattern for example the letter a as shown in Fig. 1b, is printed by the head H while traveling over a substrate, usually a paper sheet P, by a series of dots each formed by one of the vertically arranged nozzles. The accumulation of the dots completes the requested pattern.
• the head completes a line or row over the paper sheet, the latter is pulled upwards and the head commences its travel in the opposite direction (Fig. 1c) to print the requested patterns such as s at the beginning (end) of the next raw and the letter o at the end of this reverse travel.
• a method of operating printing heads comprising the steps of providing a series of at-least two printing heads; mounting the heads on a common carriage in a side-by-side, at least partly sidewise overlapping relative position, and activating the heads for printing on a substrate in a programmed periodical sequence.
• a computerized printer comprising a matrix of printing heads operable in unison.
• Fig. 1a schematically shows the face side of a typical ink-jets printing head
• Fig. 1 b illustrates the conventional printing process of a first row
• Fig. lc illustrates the conventional printing process of a second, following row
• Fig. 2a shows an assembly of four printing heads, mounted onto a common carriage
• Fig. 2b illustrates the printing process according to a first mode of operation
• Fig. 3 exemplifies the printing of certain symbols, assuming (for illustration
• Fig. 4 illustrates the use of the first mode of operation for printing the symbols of
• Fig. 5 illlustrates a second mode of operation
• Fig. 6 illustrates a third mode of operation
• Fig. 7 shows a second assembly arrangement of printing heads applicable to the
• Fig. 8 shows a third assembly arrangement of printing heads applicable to the
• FIG. 2a and 2b there is shown that more than one head —4 in the
• Mode 1 namely in exact succession
• Mode 1 printing speed is multiplied by four (or other number equal to the number of heads) without diluting the (longitudinal) density of dots.
• the vertical density remains tne same.
• Fig. 3 there are shown the letters ⁇ , b and.c. It is assumed, for the sake of explanation only, that the letters are composed of singular, discrete dots only — which of course is not the case in reality.
• Mode 1 is such that the first column is produced by head A , the second by head B, the third by C_ and the fourth by D, and so forth in the same sequence.
• the main advantage derived is, as above said, the multiplication of the carriage speed, and hence the reduction of overall printing duration.
• the dots In printing processes, it sometimes occurs that the dots must be applied more than once on the same spot. This is required if the substrate is of an absorbent, fibrous or porous material such as cardboard or even cloth; or if certain parts of a text, or portions of colored prints are to be emphasized. Conventionally, in such cases, double or triple printing is applied, causing waste of time.
• Mode 2 of the present invention method presents an effective solution, as exemplified in Fig. 5.
• Fig. 6 illustrates yet another mode of operation - Mode 3.
• This mode contributes to the art of printing in the following manner. It may occur, during the printing process, that one or more of the nozzles become clogged or otherwise cease to function properly. In conventional systems, the complete head has to be replaced, should the quality (density) of the print be retained.
• pairs (or more) of the series of heads are linked in such a fashion that one can replace the other regarding any given point.
• a dot can be applied by either one of the pair of associated heads, in a selective, i.e. programmed, manner.
• Mode 3 therefore allows for real time surveillance of the printing process, e.g. by using suitable scanners; once a local quality deterioration is observed, say because one of head A nozzle stopped working, a command will be transmitted to head C to "take over” and apply the ink to the same spot, previously fed by head A; and the same with regard to the pair of B and D heads.
• a matrix of 4x3 heads is assembled, driven by a common carriage (not shown).
• the heads A to D are not alligned one with respect to the other, resulting in a rhombus or rhomboid patterned matrixes.
• a part of head.A. is sidewise overlapped by head £; C overlaps A and ⁇ ; and D overlaps A, £ and C.
• This arrangement attains most of the benefits of the Fig. 7 arrangement, but with a considerably smaller number of heads.
• all heads of every group as heretofore described may be of the same color, of different colors, or of the multi-color type, at the designer's option.
• the advantages of the method are most striking in printing colored patterns.
• the four heads group is the most efficient, each head containing ink of one of the four basic colors (cyano, magenta, yellow and black) used in the colors separation technique.

Landscapes

• Engineering & Computer Science (AREA)
• Quality & Reliability (AREA)
• Ink Jet (AREA)
• Printers Characterized By Their Purpose (AREA)
• Electronic Switches (AREA)
• Accessory Devices And Overall Control Thereof (AREA)
• Particle Formation And Scattering Control In Inkjet Printers (AREA)

Applications Claiming Priority (3)

Publications (3)

Family

ID=11071428

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Citations (4)

Family Cites Families (4)

• 1998
  • 1998-04-23 IL IL12418298A patent/IL124182A/en not_active IP Right Cessation
• 1999
  • 1999-04-20 AT AT99914741T patent/ATE410737T1/de not_active IP Right Cessation
  • 1999-04-20 DE DE69939695T patent/DE69939695D1/de not_active Expired - Fee Related
  • 1999-04-20 WO PCT/IL1999/000209 patent/WO1999054139A2/en active Application Filing
  • 1999-04-20 EP EP99914741A patent/EP1073967B1/de not_active Expired - Lifetime
  • 1999-04-20 AU AU33436/99A patent/AU3343699A/en not_active Abandoned
  • 1999-04-20 JP JP2000544505A patent/JP2002512138A/ja active Pending

Patent Citations (4)

Non-Patent Citations (1)

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