JPS58107363A - Ink jet printer - Google Patents

Abstract

PURPOSE:To improve the printing speed without decreasing the printing quality by composing a character generator of small matrix and switching the deflection amount. CONSTITUTION:In an ink jet printer for printing a character with a dot matrix at the prescribed dot pitch, a character generator 7 is composed of a matrix smaller than the dot matrix, a chracter composing matrix is enlarged by switching the deflection amount, and is printed with the dot matrix having the dot pitch larger than that of the matrix.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements and improvements to inkjet printers,
In particular, in an inkjet printer in which characters are composed of a dot matrix, the -21 character generator is composed of a matrix smaller than the dot matrix, and the matrix of characters is enlarged by switching the amount of deflection. Printing is performed using a dot matrix with a dot pitch larger than the dot pitch of the dot matrix, thereby improving the print quality of ruled lines and the like, as well as improving the printing speed.

For example, when a structure of 40 dots in the vertical direction with a dot pitch of 1/240" (==9.1 m) is actually made up of 32 dots by changing the amount of deflection, in order to print the entire 40 dot area (for example, in the case of ruled lines, etc.) ), 20 dots were scanned in two passes.As a result, the seam between the two scans ended up in the center of the text, which significantly degraded the printing quality of the text.
However, since it requires two scans, it has drawbacks such as slow printing speed. Also, 40 dots x n (n:=12~32
), there were drawbacks such as an increase in the capacity of the character generator and a slow printing speed.

Generally, in a charge or electric deflection type inkjet recording device, ink droplets are charged and deflected according to a printing information signal and are printed on recording paper, but at this time, each ink droplet has air behind it. When a subsequent ink droplet enters this airflow, the air resistance of the subsequent ink droplet decreases, so the preceding ink droplet and the following ink droplet approach or merge, resulting in printing. Causes distortion. Furthermore, since printing ink droplets are electrically charged, a Coulomb force acts between each charged ink droplet, and this Coulomb force ζ disturbs the gap 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 shadow of the preceding charged ink droplet, which also causes printing distortion.

In order to correct such printing distortion, the applicant first stored in a RAM the amount of correction of distortion due to shadow replacement of surrounding ink droplets and the amount of correction of non-linear distortion of an individual ink droplet in accordance with the number of deflection stages. ,
It is stored in a PMOM or the like, and the correction amount is changed depending on the state of data surrounding the ink droplet (data) to be charged, so that the ink droplet can be printed at any desired and appropriate printing position. proposed an inkjet recording device (for example, Japanese Patent Application No. 55-168182
(see issue). Thus, although the above-mentioned applicant used a dot matrix configuration, the present invention has an effective 32×n and by switching the correction table of 32 dots, a virtual ζ of 40 dots can be obtained. Matrix configuration, 3
In the case of symbols, ruled lines, etc. that are larger than the 2Xn matrix configuration, a correction table with a coarser dot pitch is selected and printed.

FIG. 1 is an electrical block diagram for explaining one embodiment of the present invention, in which l is a microcomputer, 2 is a conversion table, 3 is a buffer memory, and 4 is a proportional correction table switch (PC). Memory, 5 is a latch circuit, 6 is a coincidence circuit, 7 is a character generator, 8 is a parallel in-serial shift register, 9 is a clock pulse generation circuit, 10 is a frequency divider circuit, 11 is a pulse-to-sine wave conversion circuit, 12 is an amplifier, 13 is an inkjet head, 14 is a charging electrode, 15 is a deflection electrode, 16
is the recording paper, 17 is the gutter, 18 is the address counter,
19 is a correction table 1, 20 is a gate circuit, 21 is an adder, n, 23 is a latch circuit, 24 is a digital-to-analog conversion circuit, 5 is an amplifier, 26 is a serial-in-parallel out shift register, 27 is a multiplexer, etc. is 1
A /8 frequency divider circuit is shown, and FIG. 2 is a flowchart for explaining its operation.

1 and 2, when a character code is sent to the microcomputer 1, the character code is
The code is stored in the buffer memory 3, and when the line feed or carriage return code is determined,
Now that one line of character code has been stored in buffer memory 3, the printer begins printing operation.
First, when the carriage starts scanning and a signal to start printing is generated, printing, that is, charging and deflection are started. Next, the character code from buffer memory 3 is read out, and it is determined whether it is a line feed (Lν) or a carriage return (C!R).
If it is F or CR, printing of one line is completed, and if it is not LP or OR, the character is printed according to conversion table 2.
The code is converted into a memory address of the character generator, thereby making it possible to specify the address of the character generator according to the character code. The address of the character generator is also the address of the proportional correction table switching (PC) memory 4, and it is assumed that the character code now represents A in FIG. This X character is converted to a predetermined memory address, and the fourth character is
The code shown in the figure is read out and latched into the latch circuit 5. For this character A, the correction table switching code represents "ooo", as shown in FIG. 4, and selects type A of the correction table.

At the same time, the contents of the character generator are read out, converted to serial data, and deflected according to type A of the correction table. Then, when 8 dots of data are sent out, an i-divided output is obtained, the character generator address is incremented, and the next 8 dots of data are read out and deflected. This is repeated and when the proportional code and the character generator address match, an output is obtained from the matching circuit 6 and the next character code is read out from the buffer memory 3.

This proportional code is determined by the start address and end address for the character of the character generator, and is expressed, for example, as shown in FIG.

As described above, the dot information of one character r is read out from the character generator, deflected, and printed.

Next, assuming that the character 5-code indicates j, the correction table B type is selected in the same way as above, and the proportional code is hex code #OC
'', and 32 x 12 printing is performed.Furthermore, when the character code indicates 1 (rule #), the correction table is selected from class C, but the dot pitch of class C is ”/192” (0,13■)
4" (4, 1, 23n) can be covered with 32 dots. However, the dot pitch for Class A and Class B is 1/
2. . "(:0.1 m).

As is clear from the above description, according to the present invention, the character generator maintains the configuration of 32 vertical dots, and by selecting a correction table, i'' (: 4.
It is possible to print over the entire width of 23 m), and normal characters and symbols are printed at a dot pitch of "240" (÷0.11111), so there is no deterioration in print quality.
Moreover, it has advantages such as high printing speed.

[Brief explanation of the drawing]

Fig. 1 is an electrical diagram for explaining one embodiment of the present invention, Fig. 2 is a flowchart for explaining the operation of the present invention, and Fig. 3 is the principle of operation of the present invention. FIG. 4 is a diagram showing an example of a correction table used in implementing the present invention. 1... Microcomputer, 2... Conversion f-pull, 3... Buffer memory, 4... PC memo IJ-
16... Matching circuit, 7... Character generator, 19... Correction table.

Claims (1)

[Claims] In an inkjet printer where characters are composed of a dot matrix with a predetermined dot pitch, the character
The generator is configured with a matrix smaller than the dot matrix, and by switching the amount of deflection, the matrix constituting the character can be made larger, and printing can be performed using the dot matrix with a dot pitch larger than the dot pitch of the matrix. An inkjet printer featuring