JPH02248268A - Recorder - Google Patents

Abstract

PURPOSE:To lessen deviation of a dot in a same character by a method wherein in the case of a character incapable of being recorded by one time scanning of a recording head, a character pattern is divided up and down from a base line of the character, and each of them is recorded in different scanning time. CONSTITUTION:A CPU 1 determines a vertical dot number l1 from a reference line, a lateral dot number l2, a dot number l3 to the base line BL, a large character height l4, a small character height l5, and a small character downside height l6 from a character font size of one line content character data stored in a text buffer 6 based on a character font information in a character font ROM 4. Then, when the vertical width l1 of a character dot pattern is larger than a width h of a printing head, the CPU 1 controls a printer 12 so as to record by a plurality of scans of a recording head by dividing the character pattern by the base line BL, further by l4 or l3. Deviation of a dot in a same character can be thus lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing apparatus that scans a print head to print in a dot matrix.

[Prior Art] In recent years, there have been remarkable advances in dot matrix type print heads, such as thermal heads and inkjet heads, and the quality of characters printed using these recording heads has come to rival that of printed letters. It has become. One of the advantages of a printer that performs recording using such a dot matrix head is that it can print characters having various fonts and various sizes. As a result, for example, Mincho typeface, Gothic typeface, and even capital letters for large headings,
By memorizing the dot patterns of required characters, such as medium letters for subheadings, those characters can be printed.

Dot matrix type printers are broadly classified into two types based on their structure, one of which is called a line printer. This line printer is equipped with a recording head having a length corresponding to the printing range, and feeds paper while recording line by line, and is characterized by high recording speed and high quality recording. However, this type of printer is large and expensive. The other is a printer called a serial printer, which is equipped with multiple recording heads in the vertical direction and records one line by moving the recording heads in the row direction (horizontal direction).
After recording a line, the recording paper is conveyed to the next recording line and printing is performed. This type of printer can be miniaturized and can be supplied at low cost.

[Problems to be Solved by the Invention] However, in the above-mentioned serial printer, when printing a character whose vertical width exceeds the printing width (number of dots) of the print head, it is necessary to print the entire character in one scan. Therefore, it is necessary to perform print scanning multiple times, with recording paper conveyance processing in between. For this reason, there is a problem in that the recording paper is misaligned, and "distortion" in printing is likely to occur, such as overlapping dots or gaps between dots. There is a problem in that such distortion becomes larger as the number of times the print head is scanned for one character increases.

The present invention has been made in view of the above conventional example, and identifies the font height of characters to be recorded, and compares the identified font height with the recordable height of the recording head. When a character cannot be recorded in one scan of the print head, the character pattern is divided into upper and lower parts using the character reference line as a reference, and each is recorded in different scans to reduce the misalignment of dots within the same character. The purpose is to provide a recording device with

[Means for Solving the Problems] In order to achieve the above object, the recording device of the present invention has the following configuration. That is, in a recording apparatus that records on a recording medium by moving a recording head in a direction substantially perpendicular to the conveyance direction of the recording medium, calculation for determining the height of a character pattern with respect to a reference line of a character string to be recorded is performed. means for comparing the number of recordable dots of the recording head with the height of the character pattern determined by the calculating means; When the height exceeds the number of dots of the recording head, the recording head scans and records a plurality of times, and controls the recording head to record in units of patterns above or below the reference line for each scan. have

[Operation] In the above configuration, the height of the character pattern with respect to the reference line of the character string to be printed is determined, and the number of dots that can be recorded by the recording head is compared with the determined height of the character pattern. Based on the results of this comparison, if the height of the character pattern exceeds the number of dots on the print head, the print head scans it multiple times to print, and each scan prints in units of patterns above or below the reference line. To control and to operate.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of the electronic typewriter (FIGS. 1 to 3)] FIG. 1 is a block diagram showing a schematic configuration of an electronic typewriter equipped with a thermal transfer type thermal printer according to an embodiment.

In the figure, 1 is a CPU that controls the entire device, and ROM2
It operates according to a program (flowcharts in FIGS. 7 and 8) stored in the computer. 3 is a keyboard (KB) which, in addition to character keys, is equipped with various function keys such as a character size switching key and a return key. 4 is a character font ROM that stores dot patterns of various characters. Figure 2 is a diagram showing an example of the structure of dots in the font of the character raJ stored in the character font ROMJ. In addition to this dot pattern, dot patterns of various sizes are stored in the ROMJ, such as a dot pattern consisting of 48 vertical dots (6 bytes) and 36 horizontal dots. For each of these character fonts, when a character size is designated by a key on the keyboard 3, characters of the corresponding size are read out and used.

Reference numeral 5 denotes a RAM used as a work area for the CPUI, and as shown in the figure, it is provided with various areas. That is,
A text buffer 6 stores document information inputted from the keyboard 3 or the like as code information. 7 is a print data buffer, which is an area for storing pattern information obtained by developing a character code into a character dot pattern; for example, as shown in Figure 3, it has a total of 5×N bytes, 40 bits (vertically) (5 bytes) and N bits horizontally. capacity is secured.

Here, N indicates the maximum dot width that can be printed in one printing scan.

Reference numeral 8 denotes a print character pointer, which is a pointer for indicating which of the character codes stored in the text buffer 6 is to be developed into the print data buffer 7. 9 is an unfinished character pointer that points to a character code stored in the text buffer 6 like the print character pointer 8, and because the vertical width of the character is longer than the vertical length of the print head, it is Indicates the character code that requires the same character to be printed in the next scan. A return head position 10 stores information indicating the print start position of the character code indicated by the unfinished character pointer 9, and indicates the position to which the carriage carrying the print head should return in the next scan. Reference numeral 11 denotes a display (DSP), which displays pattern information obtained by developing a pattern of the character code string stored in the text buffer 6, various messages to the operator, and the like.

A printer (PRT) 12 is capable of printing the dot data stored in the print data buffer 7.

The printer 12 mainly consists of the following three driving sections. 13
is a carriage motor drive unit, which moves the carriage in the main scanning direction, which is equipped with a thermal head consisting of 40 dots of heating elements arranged in the vertical direction (direction perpendicular to the scanning direction of the print head), and the movement of the carriage. It drives the winding up of the ribbon for thermal transfer. 14
is a feed motor drive unit that moves the printing paper in a direction perpendicular to the scanning direction of the carriage. 15 is a thermal head drive unit that presses the thermal head against the printing paper (head down) and releases it (head up), and also causes the heating element of the thermal head to generate heat according to the pattern output from the print data buffer 7. Recording is being done. Note that the carriage drive unit 13 is responsible for winding up the thermal transfer ink ribbon, and the thermal head drive unit 1 is
The head-up and head-down functions of No. 5 are designed to operate in unison, and the ribbon is wound up only when the head is down.

[Explanation regarding printed character patterns (Figures 4 to 5)
FIG. 4 is a diagram showing an example of a printing form of an English character string.

In this English character string, characters are printed based on the reference line (baseline) indicated by BL in the figure, and here, each character is printed in five areas A + A2, As in the height direction.
, A4, and A@. Area A is an area where accents attached to uppercase English letters, such as the symbol "°" in rAJ, are placed. Also, all uppercase English letters occupy area A2°A, and lowercase English letters occupy area As or area A2. As
Or area A3. Aa, or area Az, As
, included in A4. In addition, area As is the area where symbols such as underlines are placed.β1β3+
'24+β5. β indicates the vertical width related to each area of A, to As.

In this way, as is clear from Fig. 4, the character dot pattern in the character font ROMJ is composed of a predetermined number of vertical dots and a predetermined number of horizontal dots for each character size. When printing on , each character is printed in a different area forming those characters.

FIG. 5 is a diagram illustrating the 26 uppercase and lowercase letters of the alphabet, classifying which area each character occupies based on the areas shown in FIG. 4.

FIG. 5(a) shows characters occupying areas Az and A3,
26 uppercase letters and 8 lowercase letters (b, d, f.

h, i, k, 1. t) applies to this. FIG. 5(b) occupies only area A, and the 13 lowercase letters shown in the figure apply to this area. Figure 5 (C) occupies areas A s and A 4 and contains four lowercase letters (
g.

p, q, y) are applicable. Figure 5(d) occupies areas A2, As, and Aa, and the lowercase letter (j) 1
This applies to characters.

From the above, even if the vertical width of the print head during vertical printing is smaller than the vertical width β of the character dot pattern, if the vertical width of the print head is larger than the vertical width 24 of the areas Az and As, for example, ( The characters shown in a) and (b) can be printed in one printing scan. Furthermore, if the vertical width of the print head during printing is larger than the vertical width (I2S + β6) of areas A s and A 4, the characters in FIGS. 5(b) and 5(c) can be printed in one printing scan. I see what's possible.

[Explanation of character font ROM (Figure 6)] Figure 6 shows character font ROM 4 in the electronic typewriter of the embodiment.
FIG. 3 is a diagram showing an example of font information.

16.17 is the number of vertical dots ρ3 in each character dot pattern,
Number of horizontal dots 4. is held. 18 is the baseline (
The number of dots above BL) is 43.19, which is the height of the capital letter 1.
4, 20 are the heights of lowercase letters, and 21 are the heights below the baseline of lowercase letters with patterns below the baseline, I6. Reference numeral 22 indicates an area holding character dot patterns arranged in the order of character identification codes.

[Explanation of Operation (FIG. 7)] The principle of operation in the configuration of this embodiment described above will be explained using the flowchart of FIG. 7.

In the figure, h indicates the print width of the print head, l+ to fL correspond to 11 to i6 in Fig. 4, and A1 to As correspond to the fourth
This corresponds to the width and area shown in the figure. Based on the character font size of one line of character data stored in the text buffer 6, the character font information in the character font ROMJ shown in FIG. 6 is checked and the values 11 to fta are determined.

First, in step S1, it is compared whether the width of the print head is larger than the vertical width β of the character, that is, whether the entire line can be printed in one print scan (h≧β1). If printing is possible, in step S2, the character dot pattern corresponding to the character code in the text buffer 6 is set to character font R.
It is retrieved from OM4 and expanded to print data buffer 7.

Then, the printer 12 is activated and one line is printed. Here, in one scan, all the character strings on that line are printed.

In step S1, the vertical width β of the character dot pattern is determined.

is larger than the width of the print head, step S3
Then, it is compared whether the area above the baseline can be printed in one printing scan (h≧j23).

If printing is possible, the process advances to step S4, and the area At.

A2. A3 is printed in the first scan, then step S5
Area A4 below the baseline. As is printed in the second scan. In this case, the English lowercase letters g, p, q, y,
The printing of the five characters of j is divided into two scans, but the other alphabetic characters are printed in one scan. Similarly, the number of vertical dots in the area is compared with the number of dots being printed by the print head so that as many English characters as possible can be printed in one scan.

If the print head width is smaller than β in step S3, the process advances to step S6, and areas A2As, A4 . As
The width of the print head and βl are used to determine whether the
-! The judgment is made by comparing 23 and 24. Similarly, in step S9, areas A3, A4 . As, in step S12, area Ax, As, A4, step 3
16, area A2. It is determined whether or not A3 can be printed in one scan, areas As and A4 in step S20, and area A in step 324 can be printed in one scan.

Step 36. If the conditions are satisfied in step S9,
Print scanning is performed twice in steps S7 and S8 or in steps S10 and Sll.

On the other hand, step S12. S16. If the conditions are satisfied in S20 and S24, three print scans are required for each.

If the width of the print head is smaller than 1 in step S24, the process advances to step S28, where printing is performed every h dots from the top of the print line, and the total is [(J21 +h-1)/h.
One line of printing is completed by performing one printing scan.

Although not described in detail, when proceeding from the first to the second printing scan and from the second to the third printing scan, the carriage motor drive section 13 is driven to move the return head position 10.
Return the carriage to. And feed motor drive section 15
By driving the recording paper, the recording paper is moved in a direction perpendicular to the scanning direction of the print head.

For example, in step SIO, the area AI is
, A2 is printed (only the dot pattern corresponding to area A1.A2 is developed and printed in the print data buffer 7), and 2
Before the second scan, the print head moves to area A3. Aa, A
Move the recording paper to position s and proceed to step 31.
Print the second scanning area As, A4, As of 1 (
Area A3゜A4. Only the dot pattern corresponding to All is developed into the print data buffer 7 and printed.
Paper feeding when performing divided printing in each step is controlled using a similar concept.

L and other embodiments] In the processing procedure of this embodiment described above, character strings are
A method has been described in which the character dot pattern is divided into areas (in the scanning direction of the print head) and is avoided as much as possible from printing a character dot pattern that spans each area in multiple print scans.

Furthermore, by applying this method, it is possible to further avoid printing the character dot pattern in multiple printing scans. In other words, for characters that can be partially printed in the first printing scan, and characters that can be printed in the second and subsequent scans, the character dot pattern is created by not printing anything in the first scan. This prevents printing from being divided into multiple printing scans. The principle of this operation will be explained using the flowchart of FIG.

Step S29. S30 is steps S1 and S2 in FIG.
Similarly, one print scan completes one line (area Am,
Ax, As. A4. This shows the operation when it is possible to print AI).

If one stroke cannot be printed in one scan in step 329, areas A and A are printed in step S31.

It is determined whether A can be printed in one printing scan, and in step S32, a character with a dot pattern only above the baseline ((a) in FIG. 5) is determined.

It is determined whether letters (b)) can be printed in one scan, and lowercase English letters ((C) in FIG. 5) having data below the baseline can be printed in one scan. In this case, proceed to step 333, and in the first □ scan, the area AI
, characters with data in A2 ((a), (b) in Figure 5)
Only the area A 1 + A 2 * A s is printed, and then the process proceeds to step S34, where (
The characters shown in b), (c), and (d) are printed in the second scan. Therefore, at this time, the only character in the alphabet that is divided into two scans is the one character shown in FIG. 5(d). The paper feed control in this case is to print areas AI, At, and As in step 333, which is the first scan, and then print area A3 in step S34, which is the second scan.
．． 4. Since it is necessary to print A, step S3
3 to step S34, area A3 *
The recording paper is fed by the length that it moves to Aa*Aa.

In the same way, step S35. S36, S3
7, 53B, the print width of the print head is area At, A
2, A3 and area A, , A have a width that cannot be printed at the same time. Here, in step 336, the character areas (An, Aa, As) for which print data exists in area AI+A2 are printed in one scan, and then the recording paper is conveyed by the area Ai and A2, and in step S37. Only areas A s and A 4 for characters with no print data in areas A and A 2 and area A 4 for other characters are printed. Then, the recording paper is conveyed by areas A3 and A4, and in step 838, only area A is printed in the last scan. Also, step S39. S40 is step S4 in FIG. This is the same as S5.

Further, steps S41 to S53 are steps 331 to S40.
Of these, only area A+ is divided into one scan. Steps S54-358 are similar to steps S24-S28 in FIG.

In this way, in the embodiment shown in FIG. 8, the printing speed is lower than that in the embodiment explained in FIG.
On the other hand, since the number of divided printed portions of characters can be reduced, printing with less division distortion becomes possible.

In addition, in this embodiment, the characters handled are limited to English characters, but this is not limited to English characters.For example, characters such as double height characters, codes attached to characters, etc. Of course, this method can also be applied to the printing of characters and symbols whose height can be specified.

As explained above, according to this embodiment, even if the character string is larger in width than the one being printed by the print head, it is possible to avoid printing in multiple print scans as much as possible, resulting in beautiful printing. It has the effect of getting results.

[Effects of the Invention] As explained above, according to the present invention, when a character cannot be recorded in one scan of the recording head, the character pattern is divided into upper and lower parts using the reference line of the character as a reference, and each is divided into upper and lower parts in different scans. Recording has the effect of reducing the misalignment of dots within the same character.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the schematic configuration of the electronic typewriter in the embodiment, Figure 2 is a diagram showing an example of the dot configuration of a character font, Figure 3 is a diagram showing the structure of the print data buffer, and Figure 4 is an English typewriter. Figure 5 is a diagram showing an example of a printed character string; Figure 5 is a diagram classifying uppercase and lowercase letters of the alphabet according to the occupied area shown in Figure 4; Figure 6 is an example of font information for character fonts in the embodiment. FIG. 7 is a flowchart showing an example of the printing processing procedure of the CPU in the embodiment, and FIG. 8 is a flowchart showing the printing processing in another embodiment. In the figure, 1...-CPU, 2...ROM, 3...Keyboard, 4...Character font ROM, 5...RAM
, 6... Text buffer, 7... Print data buffer, 8... Print character pointer, 9... Unfinished character pointer, 10... Return head position, 11...
...Display, 12...Printer, 1
3... Carriage drive unit, 14... Feed motor drive unit, 15... Thermal head drive unit, 16...
Number of vertical dots, 17... Number of horizontal dots, 18... Number of dots up to the baseline, 19... Height of uppercase letters, 20
. . . Height above the baseline of lowercase letters, 21 . . . Height below the baseline of lowercase letters, 22 . . . Dot pattern. CANON CO., LTD. ) 10 [Area A2. A3. C (d) Figure 5 Figure 6

Claims (1)

[Scope of Claims] A recording apparatus that records on a recording medium by moving a recording head in a direction substantially perpendicular to the conveying direction of the recording medium, the height of a character pattern relative to a reference line of a character string to be recorded is determined. a calculating means for calculating the number of dots that can be recorded by the recording head, and a comparing means for comparing the height of the character pattern calculated by the calculating means, based on the comparison result by the comparing means. When the height of the character pattern exceeds the number of dots of the recording head, the recording head scans and records a plurality of times, and each scan prints in units of patterns above or below the reference line. A recording device comprising: a control means for controlling the recording device.