JP4607352B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet printing apparatus that ejects ink from nozzles to form characters on a printed material. More specifically, the present invention does not cause charged ink particles ejected one after another to land on adjacent dot positions in the deflection direction. The present invention relates to an inkjet printing apparatus that performs interlaced scanning.
[0002]
[Prior art]
As shown in FIG. 2, the conventional charge control type ink jet printer prints a vertical line by increasing the landing position in order from the lower dot.
[0003]
According to this method, distortion occurs in printing due to the influence of the air resistance of the front and rear particles during flight and the influence of the electric repulsive force caused by the charged particles.
[0004]
In order to reduce the printing distortion, it is effective to increase the distance between adjacent ink particles during flight.
[0005]
As a printing scanning method, as shown in FIG. 3, a technique of printing while skipping a predetermined number of dots at a dot position to be printed (printing while skipping every two dots in FIG. 3) (for example, Japanese Patent Laid-Open No. 3-114840) 4), or when printing characters having the same matrix in a plurality of stages as shown in FIG. 4, a technique for printing while skipping each printing stage (in FIG. 4, two stages of a 5 × 8 matrix) is known. It has been.
[0006]
In addition to the above-mentioned gazettes, for example, conventional techniques related to interlaced scanning include JP-A-7-241993 and JP-A-10-16253.
[0007]
[Problems to be solved by the invention]
The prior art has the following problems.
[0008]
As shown in FIG. 3, when printing is performed while skipping a predetermined number of dots in one line, the position in the direction substantially perpendicular to the deflection direction of the dots in one line becomes zigzag as shown in FIG. Although superior to the technology, the vertical line is distorted and the print quality is degraded. In addition, when performing multi-stage printing, the method of performing interlaced scanning for each stage is naturally not applicable to single-stage printing, and as shown in FIG. There is a problem of misalignment before printing.
[0009]
In the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 7-241993, one line is divided from region R1 to Rt, and scanning is performed while skipping a predetermined number of dots within the region R1 to print all dots. After that, interlaced scanning in the next region R2 is performed, and this scanning is repeated up to the region Rt including the top of one line. As in the present invention described later, charged ink particles are divided into a plurality of lines. This is different from the technique of interlaced scanning alternately.
[0010]
Further, the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 10-16253 is to perform time-division printing while continuously scanning a printer head. This is different from the technique of alternately scanning between a plurality of lines.
[0011]
SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet printing apparatus capable of performing interlaced scanning without causing zigzag positions of dots in one line in a perpendicular direction and without causing vertical shift in multi-stage printing. is there.
[0012]
[Means for Solving the Problems]
In the inkjet printing apparatus that performs interlaced scanning so that the charged ink particles ejected one after another do not land on adjacent dot positions in the deflection direction, the charged ink particles are alternately interlaced between a plurality of lines. Achieved by letting
[0013]
As a result, within one line, the printing dots can be landed in order on the substrate, and the vertical line is not distorted.
[0014]
Further, even in multi-stage printing, there is no problem that the upper printing is shifted before the lower printing when correcting the printing inclination.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIG.
[0016]
First, the overall configuration will be described.
[0017]
In FIG. 1, reference numeral 20 surrounded by a broken line denotes an ink jet printing apparatus (hereinafter referred to as IJP), which includes the following parts.
[0018]
1 is an MPU (microprocessing unit) that controls the entire IJP 20, 2 is a RAM (random access memory) that temporarily stores data in the inkjet printing apparatus 20, and 3 is a non-volatile memory that stores control software and data. Memory, 4 is a display device for displaying input data and printing contents, 5 is a panel interface, 6 is a panel for inputting set values such as character height, 7 is a type of ink, nozzle head cable length, use Rewriteable non-volatile storage device (HDD, flash memory, battery-backed RAM, etc.) for storing control programs and control data, printing information, charge amount detection timing, etc. in the environment, operating status, etc., 8 is printing of IJP20 9 is a print control circuit that performs general control related to Circuit, 10 is a character signal generation circuit for converting the print content into a character signal.
[0019]
11 is a nozzle that ejects ink, 12 is a charging electrode that forms particles of ink ejected from the nozzle, charges 13 are deflecting electrodes that deflect charged ink particles, and 14 collects ink that is not used for printing Gutter, 15 is a pump for supplying ink collected from the gutter to the nozzles again, 16 is a sensor for detecting the printed material, 17 is a conveyor for conveying the printed material, 25 is an encoder attached to the conveyor, and 18 is A substrate to be printed, 19 is a bus line for sending data, 21 is an interface unit with a host, 23 is a host, and 22 is an input / output circuit unit for control signals to be input / output to / from an external control device.
[0020]
FIG. 5 shows a printing interlaced scanning method in one-step printing.
[0021]
FIG. 5 shows an example in which interlaced scanning is performed every two lines.
[0022]
Since interlaced scanning is performed every two lines, the odd line timing (n) and even line timing (n + 1) are set for each dot, and the first line corresponds to the deflection position in synchronization with the odd line timing (n). To fly. For the second line, dots corresponding to a preset pitch between lines are ejected in accordance with the deflection position in synchronization with the even line timing (n + 1) after ejection. As shown in the figure, the inter-line pitch A is determined by the relationship between the number of vertical dots, the number of character width settings, and the number of interlaced lines. Since the pitch between lines in each line needs to be the same, when the number of vertical dots is equal to an integral multiple of the number of interlaced lines, the pitch between lines needs to be incremented by one.
[0023]
FIG. 6 shows an interlaced printing method in two-stage printing.
[0024]
FIG. 6 shows an example in which interlaced scanning is performed every two lines.
[0025]
As shown in the figure, even in a plurality of stages, the first line and the second line can be skipped and scanned similarly to FIG. 5 without being aware of the stages.
[0026]
Conventionally, when changing the character width (= the width between each line), a predetermined amount of idle dots are inserted (dots that do not contribute to printing) are ejected at the end of the first line or before the start of the second line. Printing on the line started.
[0027]
On the other hand, as shown in FIG. 7, the character width can be changed by increasing the inter-line pitch A. When the inter-line pitch A is increased by the character width setting value, idle dots corresponding to (character width setting number) × (interlaced line number) are inserted as shown in FIG.
[0028]
FIG. 8 shows the timing when printing is performed in synchronization with an external signal. Printing of each line is started in synchronization with an externally input clock. Since the two lines are alternately interlaced and scanned, the odd-numbered lines are printed at the odd-line timing immediately after the synchronization clock is input, and when the external synchronization signal is subsequently input, the reference timing is updated to the even-line timing. Printing of the next line is started from the even line timing immediately after the synchronization clock is input.
[0029]
FIG. 9 shows an interlaced printing scanning method for every three lines.
[0030]
Since interlaced scanning is performed every three lines, the N line timing, (N + 1) line timing, and (N + 2) line timing are set for each dot, and the first line corresponds to the deflection position in synchronization with the N line timing. To fly. In the second line, dots corresponding to a preset pitch between lines are ejected in accordance with the deflection position in synchronization with the (N + 1) line timing or (N + 2) line timing after ejection. Further, the third line flies corresponding to the deflection position in synchronization with the timing ((N + 2) or (N + 1) line timing) that is not used in the second line after ejection of dots corresponding to a preset pitch between lines. Let When the number of vertical dots coincides with an integral multiple of the number of interlaced lines, the inter-line pitch is incremented by 1 for correction. In the example of FIG. 9, since the number of vertical dots is 8, the pitch between lines is 8, and the N line timing → (N + 2) line timing → (N + 1) line timing → N line timing is repeated.
[0031]
A reference condition for determining a correction value or a correction coefficient when performing interlaced scanning for each of a plurality of lines will be described with reference to FIG.
[0032]
As shown in FIGS. 5 and 7, the change of the character width setting does not change the combination of preceding and following dots in the same line of the target dot, but the state of the front and rear lines of the target dot changes by changing the character width setting. For example, if line 13 (13) is the target dot, the immediately preceding flying dot in FIG. 5 (character width 0) is the second dot (12) from the bottom of the rear line, and the immediately following flying dot is from the bottom of the back line. In contrast to the third dot (14), there is no immediately preceding flying dot in FIG. 7 (character width 2), and the immediately following flying dot is the first dot (14) from the bottom of the rear line.
[0033]
In addition, as shown in FIG. 8, the state of the preceding and following lines of the target dot also changes depending on the period of the external synchronization signal.
[0034]
That is, not only whether the front and rear dots of the same line and the front and rear lines are dots to be printed, but also the positional relationship of the target dot and the front and rear line dots in the deflection direction changes. In general, 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. For this reason, the influence (air resistance, Coulomb force) of the dots on the front and rear lines with respect to the target dot varies 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 focus dot is determined based on the charge amount difference (for example, the charge voltage difference) between the focus dot and the dots on the front and rear lines. From the above, the reference conditions for determining the correction value or correction coefficient when performing interlaced scanning for each of a plurality of lines are as follows.
For the attention dot,
(1) Status of previous and subsequent dots on the same line (whether the dots are print dots)
(In the example of FIG. 10, front 2 dots ((9), (10)), rear 1 dot (15))
(2) Status of front and rear dots on the front and rear lines (whether the dot is a print dot or not)
(In the example of FIG. 10, front 1 dot (12), rear 1 dot (14))
(3) Charging voltage difference between front and rear dots of front and rear line and target dot In the above example, front one dot ((13)-(12)), rear one dot ((13)-(14))
In the conventional example, the case where all the ejected ink droplets are used for printing information is described. However, when one ink droplet is used among a plurality of conventional techniques (for example, out of three) If one is used, one is used for printing, and the next two flying are not used for printing). In this case, the flight order in the figure can be easily replaced with multiple chunks. Yes, the same effect can be obtained.
[0035]
【The invention's effect】
According to the present invention, a character is formed by a plurality of print lines formed in the deflection direction by causing the ink particles to reach the printed material, and the charged ink particles ejected one after another are ejected to adjacent dot positions in the deflection direction. In a continuous jet charging deflection type ink jet printing apparatus having a control device having a print control circuit for performing interlaced scanning so as not to be attached, charged ink particles are alternately placed between the plurality of print lines by the print control circuit of the control device. By performing interlaced scanning and making the landing timing of adjacent ink particles constant in each print line, the vertical position of dots in one line is further shifted without zigzag in the position in the perpendicular direction of dots in one line. Interlaced scanning is possible without any problem, and good print quality can be obtained.
[Brief description of the drawings]
FIG. 1 is an overall block diagram showing an embodiment of an ink jet printing apparatus according to the present invention.
FIG. 2 is an explanatory diagram showing an example of a dot arrangement of a print scanning method according to a conventional example and an order of performing printing.
FIG. 3 is an explanatory diagram showing an example of an interlaced print scanning method according to 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 an interlaced print scanning method according to the present invention.
FIG. 7 is an explanatory diagram showing an example (character width setting) of an interlaced print scanning method according to the present invention.
FIG. 8 is an explanatory diagram showing 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 an interlaced print scanning method (number of interlaced lines = 3) according to the present invention.
FIG. 10 is an explanatory diagram showing 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]
DESCRIPTION OF SYMBOLS 1 ... MPU, 2 ... ROM, 3 ... Flash memory, 4 ... Display apparatus, 5 ... Panel interface circuit, 6 ... Panel, 7 ... Memory | 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 ... substrate sensor, 17 ... conveyor, 18 ... substrate, 19 ... bus line, 20 ... Inkjet printing apparatus, 21 ... host interface, 22 ... control signal input / output circuit, 23 ... host, 24 ... control signal, 25 ... encoder.

Claims (5)

A nozzle Ru to generate ink particles by applying vibrations to the ink to be ejected, has a charging electrode and the deflection electrode to charge-deflecting the ink particles were formed in the deflection direction by reaching the ink particles on the printing object Continuous ejection charging deflection provided with a control device having a printing control circuit that forms characters by a plurality of printing lines and performs interlaced scanning so that charged ink particles ejected one after another do not land at adjacent dot positions in the deflection direction Type ink jet printer,
An ink jet printer characterized in that the charging control circuit of the control device causes the charged ink particles to alternately scan between a plurality of the printing lines and to make the landing timing of adjacent ink particles constant in each printing line. Printing device. 2. The ink jet printing apparatus according to claim 1, wherein the printing control circuit of the control device provides the number of lines for performing scanning by skipping the charging timing for the charged ink particles ejected one after another, and the timing corresponding to each line is repeatedly generated in order. An ink jet printing apparatus. 3. The ink jet printing apparatus according to claim 2, wherein when the character width setting is increased / decreased by the print control circuit of the control device, the insertion value of idle dots is increased / decreased for every integral multiple of the number of lines for performing interlaced scanning. Inkjet printing device. 3. The ink jet printing apparatus according to claim 2, wherein when the lines are printed in synchronization with an external synchronization signal by the print control circuit of the control device, the timing corresponding to each line provided for the number of lines for performing interlaced scanning is externally synchronized. An ink jet printing apparatus that is updated each time a signal is input and starts charging the line in synchronization with the updated timing immediately after the external synchronization signal is input. 2. The ink jet printing apparatus according to claim 1, wherein the print control circuit of the control device includes an ink particle state that flies up and down on the same line of ink particles of interest whose recording signal is corrected, and a previous line and / or a next line that flies back and forth. An ink jet which determines a correction value or a correction coefficient of the target ink particle based on a state of the ink particle and a charge amount difference between the ink particle of the previous line and / or the next line flying before and after the target ink particle Printing device.

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