JP2002254656A - Ink jet printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent print quality by making interlace scanning possible without making a position in a direction at right angles to a dot in one line zigzag and without generating displacement in the upper and lower columns in printing a plurality of columns. SOLUTION: In an ink jet printing device which conducts the interlace scanning so that charged particles jetted in succession are not flied to stick to an adjacent dot position to a deflection direction, the charged particles are alternately brought into the interlace scanning in between a plurality of lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing apparatus for ejecting ink from a nozzle to form a character on an object to be printed, and more particularly to a charged ink particle ejected successively in the direction of deflection. The present invention relates to an ink jet printing apparatus that performs interlaced scanning so as not to jump to a matching dot position.

[0002]

2. Description of the Related Art In a conventional charge control type ink jet printer, as shown in FIG. 2, dots of a vertical line are printed by sequentially increasing the landing position from the lower dot as shown in FIG.

[0003] According to this method, during the flight, distortion occurs in the print due to the influence of the air resistance of the front and rear particles and the effect of the electric repulsion due to the charged particles.

In order to reduce the printing distortion, it is effective to increase the distance between adjacent ink particles during flight.

As a printing scanning method, as shown in FIG. 3, printing is performed while skipping a dot position to be printed by a predetermined number of dots (FIG. 3 printing while skipping every two dots).
4 (for example, Japanese Patent Laid-Open No. 3-114840), or as shown in FIG. 4, when characters having the same matrix are printed in a plurality of rows, printing is performed while skipping every printing step (5 × 8 in FIG. 4). Is known in the art.

The prior art relating to interlaced scanning is as follows.
Other than the above-mentioned publications, for example, JP-A-7-241993, JP-A-10-16253 and the like can be mentioned.

[0007]

The above prior art has the following problems.

As shown in FIG. 3, when printing is performed while skipping a predetermined number of dots in one line, the position in a direction substantially perpendicular to the deflection direction of the dots in one line becomes zigzag as shown in FIG. Although superior to the described prior art, the vertical lines are distorted and the print quality is degraded. In addition, when performing multi-stage printing, the method of performing interlaced scanning for each stage cannot be naturally adopted in one-stage printing, and as shown in FIG. There is a problem that it is shifted forward compared to printing.

In the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 7-241993, one line is divided into regions R1 to Rt, and scanning is performed while skipping a predetermined number of dots in the region R1. After printing the dots, interlaced scanning in the next region R2 is performed, and this scanning is repeatedly performed up to the region Rt including the top of one line. This is different from the technique of alternately scanning between a plurality of lines.

The technique described in the above-mentioned Japanese Patent Application Laid-Open No. H10-16253 is to print in a time-division manner while continuously scanning a printer head. This is different from a technique in which particles are alternately scanned between a plurality of lines.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet printing apparatus capable of performing interlaced scanning without a zigzag position of dots in one line in a direction perpendicular to one line and without causing a shift between upper and lower stages in multi-stage printing. Is to do.

[0012]

An object of the present invention is to provide an ink jet printing apparatus which performs interlaced scanning so that charged ink particles ejected one after another are not caused to fly to dot positions adjacent in the deflection direction. This is achieved by alternately scanning between a plurality of lines.

[0013] This makes it possible to cause print dots to land on a print object in order within one line, and no vertical line distortion occurs.

[0014] Also, in multi-stage printing, when correcting the inclination of the printing, there is no problem that the upper-stage printing is shifted earlier than the lower-stage printing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

First, the overall configuration will be described.

In FIG. 1, reference numeral 20 surrounded by a broken line denotes an ink jet printing apparatus (hereinafter referred to as IJP), which is constituted by the following components.

Reference numeral 1 denotes an MPU (Micro Processing Unit) for controlling the entire IJP 20, and 2 a RAM for temporarily storing data in the ink jet printing apparatus 20.
(Random access memory), 3 is a non-volatile memory for storing control software and data, 4 is a display device for displaying input data and print contents, 5 is a panel interface, 6 is a set value such as a character height. Is a rewritable non-volatile storage device (7) for storing control programs and control data, printing information, charge amount detection timing, and the like for the type of ink, nozzle head cable length, use environment, operating conditions, and the like. HDD, flash memory, battery-backed RAM
Etc.), 8 is a print control circuit for performing general control on printing of the IJP 20, 9 is a print object detection circuit, and 10 is a character signal generation circuit for converting the print content into a character signal.

Reference numeral 11 denotes a nozzle for ejecting ink, 12 denotes a charging electrode for applying a charge to the ink particles when the ink ejected from the nozzle becomes particles, 13 denotes a deflecting electrode for deflecting the charged ink particles, and 14 denotes a printing electrode which is not used for printing. A gutter for collecting the ink, 15 is a pump for supplying the ink collected from the gutter to the nozzle again, 16 is a sensor for detecting the print object, 17 is a conveyor for conveying the print object, and 25 is an encoder attached to the conveyor. Reference numeral 18 denotes an object to be printed, reference numeral 19 denotes a bus line for transmitting data and the like, reference numeral 21 denotes an interface with a host, reference numeral 23 denotes a host, and reference numeral 22 denotes an input / output circuit for inputting / outputting a control signal to / from an external control device. is there.

FIG. 5 shows a print skip scanning method in one-stage printing.

FIG. 5 shows an example in which interlaced scanning is performed every two lines.

Since interlaced scanning is performed every two lines,
The odd line timing (n) and the even line timing (n + 1) are set for each dot, and the first line is caused to fly in accordance with the deflection position in synchronization with the odd line timing (n). In the second line, dots of a predetermined pitch between lines are ejected and are ejected in accordance with the deflection position in synchronization with the even-numbered line timing (n + 1).
As shown in the figure, the pitch A between the lines is determined by the relationship between the number of vertical dots, the set number of character widths, and the number of interlaced lines. Since the pitch between lines in each line needs to be the same, if the number of vertical dots matches an integer multiple of the number of interlaced lines, it is necessary to increase the pitch between lines by +1 for pitch adjustment.

FIG. 6 shows a print skip scanning method in two-stage printing.

FIG. 6 shows an example in which interlaced scanning is performed every two lines.

As shown in the figure, even in a plurality of stages, the first line and the second line can be skipped similarly to FIG. 5 without being aware of the stage.

Conventionally, when changing the character width (= width between lines), a predetermined amount of idle dots is inserted at the end of the first line or before the start of the second line (dots that do not contribute to printing are ejected). After that, the printing of the second line was started.

On the other hand, as shown in FIG. 7, the character width can be changed by increasing the pitch A between the lines. When the pitch A between lines is increased by the character width setting value, as shown in FIG.
Insert play dots for (number of skipped lines).

FIG. 8 shows the timing when printing is performed in synchronization with an external signal. Printing of each line is started in synchronization with a clock input from the outside. In order to alternately scan two lines, the printing of odd lines is started at the timing for odd lines immediately after the input of the synchronization clock, and when an external synchronization signal is subsequently input, the reference timing is updated to the timing for even lines. Printing of the next line is started from the timing for the even-numbered line immediately after the input of the synchronous clock.

FIG. 9 shows a print skip scanning method for every three lines.

Since interlaced scanning is performed every three lines,
The timing for N lines, the timing for (N + 1) lines, and the timing for (N + 2) lines are set for each dot.
The line flies in accordance with the deflection position in synchronization with the N-line timing. In the second line, after ejecting dots of a preset inter-line pitch, they are ejected in accordance with the deflection position in synchronization with the (N + 1) -line timing or the (N + 2) -line timing. Further, the third line flies in response to the deflection position in synchronization with the timing (dots for the (N + 2) or (N + 1) line) that has not been used in the second line after the ejection of the preset pitch between the lines. Let it. When the number of vertical dots matches the integral multiple of the number of interlaced lines, the pitch between lines is increased by one for correction. In the example of FIG. 9, since the number of vertical dots is 8, the pitch between lines is 8, and the timing for N lines → the timing for (N + 2) lines → the timing for (N + 1) lines → the timing for N lines is repeated.

Referring to FIG. 10, reference conditions for determining a correction value or a correction coefficient when interlaced scanning is performed for each of a plurality of lines will be described.

As shown in FIGS. 5 and 7, the change of the character width setting does not change the combination of the dots before and after the target dot on the same line, but the change of the character width setting changes the state of the lines before and after the target dot. For example, if (13) of line 1 is a dot of interest, FIG. 5 (character width 0)
In FIG. 7 (character width 2), the immediately preceding flying dot is the second dot (12) from the bottom of the rear line, and the immediately following flying dot is the third dot (14) from the bottom of the rear line. There is no immediately preceding flying dot in, and the immediately following flying dot is the first dot (14) from the bottom of the following line.

As shown in FIG. 8, the state of the line before and after the target dot changes depending on the period of the external synchronization signal.

That is, the positional relationship between the target dot and the preceding and succeeding line dots in the deflecting direction changes as well as whether or not the preceding and succeeding dots on the same line and the preceding and succeeding lines are dots to be printed. Generally, as the character width setting value is increased / the period of the external synchronization signal is longer, the arrangement difference in the deflection direction increases. Therefore, the influence of the dots on the front and rear lines (air resistance, Coulomb force) on the target dot changes depending on the character width setting value or the period of the external synchronization signal. Since the position in the deflection direction is related to the charge amount of the dot, the correction value or correction coefficient of the target dot is determined based on the charge amount difference (for example, the charging voltage difference) between the target dot and the dots on the preceding and succeeding lines. From the above, reference conditions for determining a correction value or a correction coefficient when performing interlaced scanning for each of a plurality of lines are as follows. (1) State of dot before and after the same line (whether the dot is a print dot) (2) The state of the front and rear dots of the front and rear lines (whether the dots are print dots) (In the example of FIG. 10, one front dot (12) and one rear dot (1
4)) (3) Charging voltage difference between preceding and succeeding dots of the preceding and succeeding lines and the dot of interest In the above example, one dot before ((13)-(12)), one dot after ((13)-(14)) In the above conventional example The case where all ejected ink droplets are used for print information is described. However, when one ink droplet is used among a plurality of ink droplets which is a conventionally known technique (for example, one ink droplet is used among three ink droplets). In this case, one piece is used for printing, and two pieces that fly subsequently are not used for printing). However, by replacing the flight order in the figure with a plurality of groups, it is possible to easily carry out the same operation. The effect can be obtained.

[0035]

According to the present invention, it is possible to perform interlaced scanning without causing the zigzag position of the dots in one line in the perpendicular direction in one line, and furthermore, without causing a shift between upper and lower stages in multi-stage printing. Quality can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall block diagram illustrating an embodiment of an inkjet printing apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a conventional dot arrangement of a printing scan method and an order of printing.

FIG. 3 is an explanatory diagram showing an example of an interlaced print scanning method which is a conventional example.

FIG. 4 is an explanatory diagram showing an example (a plurality of stages) of an interlaced print scanning method according to a conventional example.

FIG. 5 is an explanatory diagram showing an example of an interlaced print scanning method according to the present invention.

FIG. 6 is an explanatory diagram showing an example (a plurality of stages) of the interlaced print scanning method according to the present invention.

FIG. 7 is an explanatory diagram showing an example of the interlaced print scanning method (character width setting) according to the present invention.

FIG. 8 is an explanatory diagram illustrating an example of an interlaced print scanning method (external synchronization signal input) according to the present invention.

FIG. 9 is an explanatory diagram showing an example of the interlaced print scanning method (interlaced line number = 3) according to the present invention.

FIG. 10 is an explanatory diagram illustrating an example of determining a correction value or a correction coefficient of the interlaced print scanning method according to the present invention.

[Explanation of symbols]

1. MPU, 2. ROM, 3. Flash memory, 4.
Display device, 5: Panel interface circuit, 6: Panel, 7: Storage device, 8: Print control circuit, 9: Printed object detection circuit, 10: Character signal generation circuit, 11: Nozzle, 12
... Charging electrode, 13 ... Deflection electrode, 14 ... Gutter, 15 ... Pump, 16 ... Printed object sensor, 17 ... Conveyer, 18 ...
Printed object, 19: bus line, 20: inkjet printing device, 21: host interface, 22: control signal input / output circuit, 23: host, 24: control signal, 25 ...
Encoder.

Claims (5)

[Claims] An ink is ejected to generate ink particles by vibrating the ink, and the ink particles are charged and deflected so that the ink particles reach a printing target to form characters, and are successively ejected. An ink jet printing apparatus that performs interlaced scanning so as not to cause charged ink particles to fly to dot positions adjacent to each other in a deflection direction, wherein the charged ink particles are alternately interleaved and scanned between a plurality of lines. apparatus. 2. The ink-jet printing method according to claim 1, wherein charging timings for the charged ink particles ejected one after another are provided for the number of lines for skipping scanning, and the timing corresponding to each line is repeatedly generated in order. apparatus. 3. The ink-jet printing apparatus according to claim 2, wherein, when the character width setting is increased or decreased, the insertion value of the idle dot is increased or decreased for each integral multiple of the number of lines for performing interlaced scanning. 4. The printing method according to claim 2, wherein when printing each line in synchronization with the external synchronization signal, the timing corresponding to each line provided for the number of lines for performing interlaced scanning is updated every time the external synchronization signal is input. An ink jet printing apparatus, wherein charging of the line is started in synchronization with the updated timing immediately after the input of the external synchronization signal. 5. The method according to claim 1, wherein the state of the ink particles flying up and down on the same line of the target ink particle for correcting the recording signal, the state of the ink particles on the previous line and / or the next line flying back and forth, An ink jet printing apparatus, wherein a correction value or a correction coefficient of the target ink particle is determined based on a charge amount difference between the ink particles of a previous line and / or a next line and the target ink particle.