JPS59106975A - Printing distortion correcting apparatus of charge deflecting type ink jet printing apparatus - Google Patents

Abstract

PURPOSE:To prevent printing distortion and the mutual overlapping of printed letters, by changing the printing order in a pattern only in taking a certain pattern without converting data. CONSTITUTION:Printing data sent as dot information by an electric circuit for changing over a deflected droplet is inputted to a shift register 18. A clock (CLOCK 2) is shifted in synchronous relation to one droplet and the outputs of eight bits Q1-Q8 of the shift register 18 are sent to a pattern decorder 19 as information for showing the patterns of previous and succeeding ink droplets while one or a plurality of 16 kinds of pattern outputs Q0-Q15 are outputted. A clock (CLOCK 1) drives a nine-bit address counter 11 to successively read a distortion correcting ROM12 and the output of a multiplexer 20 is successively read out by the lower rank four bits (S0-S3) of the address while a gate circuit 14 determines whether the correcting code is added or not to send only the code to be corrected to an adder 15. A printing order is changed only by relatively adding and subtracting a charge code.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a printing distortion correction device for a charge deflection type inkjet printing device.

BACKGROUND OF THE INVENTION Generally, in a charge deflection type inkjet printing apparatus, ink droplets are charged and deflected according to printing information, and are printed on recording paper. At this time, each ink droplet creates an air flow behind it, and when the subsequent ink droplet enters this airflow, the air resistance of the subsequent ink droplet decreases, so the preceding and following ink droplets approach each other. or they may combine to cause printing distortion. Since printing ink droplets are electrically charged, Coulomb force acts between each charged ink droplet, and this Coulomb force disturbs the spacing between each ink droplet, causing printing distortion. Furthermore, the amount of charge of the ink droplet that is about to be charged is reduced by the effect of the preceding charged ink droplet, which also causes printing distortion. To solve this problem, for example, as shown in Japanese Patent Publication No. 52-30330, the distance between the ink droplets is increased by printing the deflection stage intermittently instead of sequentially from the top or bottom. Additionally, it has been proposed to reduce printing distortion.

Fig. 1 is a diagram for explaining an example of the above-mentioned conventional printing pattern. For example, the figure (B) in the case of printing is ■, ■, ■, 0...0, ■,
The figure below shows the case of non-sequential printing in which characters are printed intermittently as ・・・■,■,・・・・・・■,■.However, when printing intermittently like this, due to the influence of the carriage, (B) The vertical lines appear jagged as shown in the image.

FIG. 2 is a diagram showing an example of a data conversion circuit for non-sequential printing shown in FIG.
is Paran number 114 serial out type shift register,
6 is a timing controller, 7 is a multiplexer,
The data to be printed on the matrix of ■～■ stages (
2 values) are input to the serial-in/parallel-out type register 1, and when it is input to the 0th stage, ■, ■, ■... The 0th stage is loaded to the parallel-in/serial-out type register 2, and then one Shifted■、■・・・・・・0
The column is loaded to 3, and in the same way, ■, ■...0
The stage is loaded into 4, ■, ■ - 0 stage is loaded into 5, and these registers 2 to 5 are loaded into 2 by the timing controller 6.
3.4.5, the data loaded into each register is sent out as serial data, and as shown in FIG. 1(B),
0%...■,■,■・■,■,■・・・@,■,■・
・Printed in the order of ■. However, when printing in this non-sequential manner, as shown in Figure 1 (B), jaggedness occurs in the vertical lines, and as shown in Figure 2, a data conversion circuit is required. It is.

On the other hand, if the ink droplets are deflected in order from the bottom of the matrix, for example, if the letters ■, ■, ■, ■, ■ are printed in order from the bottom as shown in Figure 3 (4). , the leading part ■ is distorted because there is no ink droplet in front of it, and when we try to correct this, the ink droplet ■ appears as shown in Figure 3 (B).
and ■ will be merged. In such a case, as shown in Figure 3 (0), if the printing order of the ink droplets ■ and ■ is switched, the merging of the ink drops ■ and ■ will disappear. There are many cases in which distortion can be reduced by replacing the

The present invention was made in view of the actual situation as described above, and in particular, it does not convert data, but only when a certain pattern is met.
This is done for the purpose of changing the printing order within a pattern, thereby preventing print distortion and merging of printed portions.

C. The configuration of the present invention will be described below based on one embodiment.

FIG. 4 is an electric circuit diagram for explaining an example of a circuit configuration for replacing uneven thickness parts, and FIG. 5 is a detailed diagram of part A in FIG. 4. In the figure, 11 is an address counter. , 12 is a distortion correction ROM, 13 is a counter timing circuit, 14 is a gate circuit, 15 is an adder circuit, 16.17 is a latch circuit,
18 is a shift register, 19 is a pattern decoder, 1 is a multiplexer, 2] is a gate circuit, 22 is a decoder, and print data sent as dot information is input to the shift register 18. The input clock (CLOCK 2 ) of this shift register 18 is synchronized with the effective number of printing waves, and is shifted in synchronization with the printing of one drop. Furthermore, the 8-bit output Ql to Q8 of the shift register 18 is sent to the pattern decoder 19 as information indicating the pattern of the previous and subsequent ink droplets, and the output Q of the pattern decoder 19 indicates which of the 16 types of patterns it applies to. . - Appears on one or more of the 16 outputs of Ql5. Note that the clock (CLOCKl) that drives the 9-bit address counter 11 has a frequency 16 times that of CLOCK2, and specifies the address of the distortion correction ROM 12 using this clock.

FIG. 6 is a diagram showing an example of the distortion correction ROM 12, and addresses 00 to 07 contain the first stage 2 correction (correction code when the subsequent two drops are deflected), K1 correction, vcs::
(standard correction code), S0 correction (correction code when one preceding drop is deflected), S2 correction, S3 correction, and S5 correction codes are stored, and the first stage special pattern is stored in 08 to OF. A correction code has been entered. Similarly, the second stage correction code is input to 10 to IF, and the 32nd stage correction code is input to IFO to IFF.

9-bit address counter 11: OO-OF.

10 to IF and sequentially read out the distortion correction ROM 12, the lower 4 bits (So'sa) of the output address of the multiplexer 20 select llp, and the gate circuit 14 sequentially reads out the correction code. It is decided whether to add or not, and only the code to be corrected is sent to the adder 15.The addition result of the adder 15 is latched by the latch circuit 16, and
When added six times, it is latched by the latch circuit 17,
The latch result of the latch circuit 16 is reset. In addition,
In this case, even when the ink droplet is charged, only the correction code may be added to the latch result of the latch circuit 17, so the gate circuit 21 allows the charge code to pass only when charging. /A converter to generate charging voltage.

Now, as mentioned above, distortion occurs when printing as shown in Figure 3 (C), so in order to prevent this, if you want to replace ■ and ■ as shown in Figure 3 (C), To explain the case that corresponds to the pattern shown in ), the seventh
In the figure, black circles indicate printing stages and white circles indicate non-printing stages. In Fig. 7 (5), printing Y1 oil
・Sl・S2・S3・S4・S5. That is, in this example, the trailing drop and the leading drop are charged, and the leading drop is charged.
-5 drops are not charged. In this case, the output of Q9 of the pattern decoder 19 in FIG. 5 becomes "1",
Gate circuit] 4 outputs the correction code P2 shown in FIG.

Therefore, if a code corresponding to the difference with the adjacent stage is inputted into this correction code, the ■ shown in FIG. 3(5) is deflected as high as the position of ■. In addition, if it corresponds to the pattern in Figure 7 (B),
4.For S5, for example, pattern decoder】Q of 9,
. Assuming that the output of is ``1'', the correction code P3 shown in FIG. 6 is added.

When the complement of P2 is entered into this supplementary code, the direction of ■ is reduced by one step by 1@, and as a result, ■ shown in Figure 3 is deflected low to the position of ■, and as a result, ■
and ■ can be interchanged.

Effects As is clear from the above explanation, according to the present invention, the printing order can be changed by relatively adding and subtracting the charge codes without converting the print data, thereby reducing printing distortion (merging ) can be significantly reduced. In particular, in the present invention, only the positional relationship (dot order) of some dots within the pattern changes, so that the jaggedness of the vertical lines does not appear in a large scale.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional printing pattern, FIG. 2 is a diagram showing an example of an electric circuit for obtaining the printing pattern shown in FIG. 1(B), and FIG. 3 is a diagram showing an example of a conventional printing pattern. 4 is an electric circuit diagram for explaining an embodiment of the present invention, and FIG. 5 is a part A of FIG. 4. 6 is a diagram showing an example of a distortion correction ROM, and FIG. 7 is a dot configuration diagram for explaining an example of the operation of the present invention. 11 Address counter, 12 Distortion correction ROM, 1
3. Counter timing circuit, 14... Gate circuit,
15...Addition circuit, ]6.17 Latch circuit, 18.
Shift register, 19... pattern decoder, addition...
Multiplexer, 21...gate circuit, 22...decoder.

Claims (1)

[Claims] means for charging ink droplets ejected from a nozzle; means for applying a deflection electric field to the charged ink droplets to direct them;
In a charged deflection type inkjet printing apparatus having means for forming a pattern on a printing surface using deflected ink droplets, means for determining whether or not a pattern to be printed matches a preset printing pattern; . Printing distortion of a charge deflection type inkjet printing apparatus, characterized in that when it is determined by the discrimination means that the pattern matches, the charge level of the charging means is changed in a manner that satisfies the shape of the printed pattern. correction device.