JPH1016300A - Printing pitch correcting method for printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct a printing pitch correcting operation without affecting the printing processing speed by subtracting a printing starting position painter for one dot when a printing pitch error accumulated and retained for each character reaches a value larger than one dot so as to displace the printing position of character data by one dot. SOLUTION: A CPU 2 of a printer 1 awaits printing data and printing command information dispatched from a host position 10. Subject to the receipt, the printing command information is analyzed and stored in a buffer 51. The left margin amount is set by a pitch unit of an ANK character. Judgment is made on whether or not data for one line have been received. If the judgment result is negative, it remains in a waiting state for data. On the other hand, the result is positive, an area for developing the printing data is ensured in a certain area in a RAM 5 according to the printing command information so that the received printing data are developed in the certain area for each one character. A printing pitch correcting processing and an error accumulating processing are conducted for each one character.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot matrix type printer which performs a printing operation by moving a print head in a row direction and corrects a printing pitch error generated according to a set value of a character pitch. About the method.

[0002]

2. Description of the Related Art Conventionally, there is a dot matrix type printer which performs a printing operation by moving a dot impact type or thermal type print head in a row direction. In such a printer, the number of dots to be printed in a range of 1 inch (hereinafter referred to as dot density) Di dpi (Dots Per Inch)
Is determined by the dot pitch of the print head. on the other hand,
The number of characters (hereinafter referred to as a character pitch) Cpcpi (Character Per Inch) to be printed in a range of one inch is arbitrarily set according to the printing specifications. Here, the number of dots Cd required to print one character (hereinafter, the number of character dots) Cd is defined by the following equation (1). Cd = Di / Cp (1) For example, the dot density Di is set to 180 dpi, and the character pitch Cp is set.
Is 10 cpi, the number of character dots C
d is 18 dots / character. Also, Di = 180dpi
, Cp = 12 cpi, Cd =
It becomes 15 dots / character. The printer performs a printing operation based on the number of character dots Cd set in this way.

However, depending on the character pitch Cp, the number of character dots Cd may not be an integer but may be a fraction below the decimal point. For example, if the dot density Di is 180 dp
When the character pitch Cp is set to 13 cpi when i, the calculated character dot number Cd is 13.8 dots /
It becomes a character and a fraction after the decimal point (actually, there is a fraction below the second decimal place but omitted). Since it is impossible to perform a printing operation based on the number of character dots including the fraction below the decimal point, if a fraction occurs in the number of character dots Cd, the fraction is rounded up or down to obtain the number of character dots Cd. (14 dots / character in this example)
Printing must be performed based on the

[0004] When generating print data to be printed in the range of the maximum print width of the printer, a higher-level device that supplies print data to the printer determines the number of characters per line based on the calculated character pitch Cp. For this reason, when the calculated character pitch includes a fractional part below the decimal point, the number of characters for one line given to the printer from the host device matches the number of characters for one line printable by the printer. In some cases, there is a problem that a part of the print data given to the printer is not printed. For example, if the dot density Di of the print head of the printer is 180 dpi and the character pitch Cp is set to 13 cpi, the calculated character dot number Cd is 13.8 dots / character. Here, the printer must print the number of character dots Cd in units of, for example, 14 dots / character, so that a printing pitch error of 14-13.8 = 0.2 dots occurs for one character. If the maximum print width of the printer is 960 dots, and if the calculated number of character dots is 13.8 dots / character, 960 / 13.8 = 69 characters of print data per line should be printable. is there. However, the characters that can be actually printed by the printer are 960/1 per line because the actual number of character dots is 14 dots / character.
4 = Only 68 characters can be printed. In other words, the host device assumes that the character pitch is 13 cpi and the print data 6 for one line
Even if nine characters are sent out, the printer can print only 68 characters, and cannot print the last one character.

In order to eliminate such inconvenience, it is necessary to correct the printing pitch so that printing corresponding to the calculated number of character dots can be performed. Conventionally, during the printing period of one line in a printer, the moving speed of the print head is delayed by an amount corresponding to the printing time of one character, so that all the printing data of one line sent from the host device is printed. The printing pitch correction method described above is adopted.

[0006]

However, in the above-described conventional printing pitch correction method, since the moving speed of the print head is delayed, there is a disadvantage that the printing processing speed of the printer is reduced. In addition, when such a correction operation is performed, as the character pitch Cp is larger, that is, as the number of character dots Cd is larger, the printing time for one character is longer, so that the time for delaying the moving speed of the print head is longer. This causes a problem that the printing processing speed is further reduced. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a printer that performs a print pitch correction operation without affecting a print processing speed.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a dot matrix type printer for performing a printing operation by moving a print head in a row direction, wherein the dot density of the print head represented by the number of dots per unit size is represented by Di. And the character pitch indicated by the number of characters printed per unit dimension is C
In the case of p, the number of character dots Cd indicated by the number of dots required to print one character (where Cd = Di
/ Cp) for correcting a printing pitch error caused by a fraction below a decimal point, which is determined by the width of a character specified by printing data sent from a host device. Error accumulation processing for accumulating and holding the printing pitch error one character at a time;
It is determined whether or not the cumulative value of the print pitch error has reached a value of 1 dot or more. If the determination result is affirmative, a print start position pointer indicating the print start position of the print data on the print medium is set to 1 dot. After subtracting one dot from the cumulative value of the print pitch error, the process proceeds to the error accumulation process. If the determination result is negative, the print pitch correction process returns to the error accumulation process. It is characterized in that it is repeatedly executed for each character during the printing operation. According to the above method, the print pitch error is accumulated and held for each character, and when the accumulated value reaches a value of one dot or more, the print start position pointer is decremented by one dot, whereby the character is printed. Data print position is 1
The printing pitch is shifted by the amount corresponding to one dot, and the error of the printing pitch for one dot is corrected.

According to the present invention, at the start of a one-line printing operation, a print pitch error caused by a left margin amount set in a left margin pointer based on print command information sent from a host device is a value of one dot or more. If the determination result is affirmative, the printing start position pointer is subtracted from the printing pitch error by the number of dots corresponding to the value obtained by rounding down the value after the decimal point, and then the process proceeds to error accumulation processing. If the determination result is negative, the process directly proceeds to the error accumulation processing. According to the above method, a correction is also made for a print pitch error caused by a left margin set for each line.

The present invention is characterized in that the cumulative value of the printing pitch error is handled by being converted into a minimum width character unit. According to the above method, since the print pitch error is handled by converting it to a character unit having the minimum width, it is not necessary to handle the print pitch error having a value below the decimal point, and the numerical processing is simplified.

[0010]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of a printer using the print pitch correction method of the present invention. The printer 1 performs a printing operation based on print data transmitted from the host device 10. The CPU 2 controls the following units. The ROM 3 stores a control program for the CPU 1 and the like. The font ROM 4 stores font data as print data.

The RAM 5 includes a buffer 51 for storing print command information sent from the host device 10, a cumulative counter 52 for counting a value corresponding to a cumulative value of a print pitch error described later, A left margin pointer (hereinafter referred to as an LM pointer) 53 for holding a left margin amount (left margin amount), and a printing position on a printing medium for printing out print data (font data) on a printing medium in dot units. And a print start position pointer 54 for managing the data. Note that the left margin amount and the origin of the print position correspond to the left end position on the print medium.

The print command information is information sent together with print data from the host device 10 to the printer 1, and is information necessary for developing one line of print data in a predetermined area of the RAM 5. Print data amount,
The information includes a left margin amount in the line and other information necessary for a printing operation.

The left margin amount managed by the LM pointer 53 is updated based on the print command information before the start of one line printing operation. The managed print start position is updated for each character.

The communication unit 6 receives print data and print command information provided from the host device 10, and
This is for transmitting predetermined response data to the host device. The printing unit 7 performs a printing operation by moving a dot impact type or thermal type print head (not shown) in the row direction. The transport unit 8 transports a print medium.

FIGS. 2A to 2D are illustrations showing the width of each character printed by the printer.
The vertical size H is 24 dots for all character types. FIG. 2A shows a normal ANK character (Alphabetic Nume).
tric Kana) and half-pitch double-width characters.
In this embodiment, the width W is 14 dots. FIG. 2B shows a dot configuration of double-width characters of normal kanji and ANK characters. Since the width is twice the width of the ANK character in FIG. 2A, the width W is configured by 28 dots. FIG. 2C shows a dot configuration of half-width characters (half pitch) of ANK characters and half spaces. The width is composed of 7 dots. FIG. 2D shows a dot configuration of a double-width Chinese character. The width W is composed of 56 dots.

As shown in FIG. 2C, the minimum width W that can be printed by this printer is 7 dots. here,
Assuming that the width of the smallest character (half-width character of ANK character and half space) shown in FIG. 2C is one unit, FIG.
ANK characters and half-pitch double-width characters are 2 units, and Kanji and ANK characters in FIG. 2B are 4 units.
The double-width character of the kanji in FIG. 2D is 8 units. That is, each character is configured to have a width that is an integral multiple of the width of the minimum character. As described later, the RAM of FIG.
The accumulation counter 54 of 5 counts the accumulated value of the number of characters included in one line, with the width of the minimum character as one unit. This cumulative value of the number of characters corresponds to the cumulative value of the printing pitch error, as described later.

Tables 1 to 3 are tables showing the correction state of the character pitch. When the dot density Di of the print head of the printer is set to 180 dpi and the character pitch Cp is set to 13 cpi, the state of printing with only normal ANK characters (FIG. 2A) is shown in Table 1. ) Is shown in Table 2, and the state printed only at half pitch (half-width) is shown in Table 3. Each cell corresponds to one character.

[Table 1]

[Table 2]

[Table 3]

The cumulative dot count A1 without correction indicates the cumulative value of the print dot count when the print pitch correction operation is not performed. The calculated cumulative dot number A2 indicates the cumulative value of the number of print dots in the number of character dots Cd including a fraction below the decimal point. The corrected cumulative dot number A3 indicates the cumulative value of the number of print dots when correction is performed by the method of the present invention. The print pitch error cumulative value B is the difference between the calculated cumulative dot number A2 and the corrected cumulative dot number A3. The count value C of the cumulative counter is a count value of the number of characters when the previously described minimum width character is converted into one unit, and the printing pitch error per character is replaced with the minimum width character number as described later. Shows numerical values. 3 shows a count value of an accumulation counter 52 of the RAM 5 shown in FIG. Therefore, the first character, 2
The cumulative dot numbers A1 to A in the order of the third character, the third character,.
3. Cumulative value B of print pitch error and cumulative counter 52
Are added.

Taking Table 1 as an example, the cumulative dot number A1 per ANK character is 14 dots, and the calculated cumulative dot number A2 is 13.8 dots. Is the difference between the two.
It becomes 2 dots. Hereinafter, the cumulative value C of the printing pitch error is
As the number of characters increases by one character, the number increases in units of 0.2 dots. However, the fifth character reaches exactly one dot.
That is, in the fifth character, the cumulative dot number A1 when the correction operation is not performed is 70 dots for five 14 characters. Here, the corresponding calculated cumulative dot number A2
Is 69 dots for 5 characters of 13.8 dots, and the print pitch error Ep is 1 dot.

Therefore, in the course of the printing operation, 5
By correcting the position of the first dot of the character by one dot to the fourteenth dot of the fourth character, as indicated by the symbol * (asterisk) in Table 1, the cumulative number of dots of the fifth character is It can be the same as the calculated cumulative dot number A2. Thus, the accumulated value C of the print pitch error is just 1
By performing a correction operation for one dot when the value reaches a value equal to or larger than a dot and smaller than two dots, a printing pitch error can be corrected in units of one dot.

The printing pitch error Ep per character is a value proportional to the width of the character. Therefore, it is determined whether or not the accumulated value of the printing pitch errors of the characters to be printed has reached one dot or more, and the correction operation may be performed when the determination result is affirmative.

Here, if the printing pitch error represented by a numerical value after the decimal point is handled as it is, there is an inconvenience that the numerical processing becomes complicated. Therefore, the printing pitch error is replaced (converted) into a character unit having the minimum width. And the cumulative counter value C
, The printing pitch error is treated as an integer and the processing is simplified.

In this embodiment, the number of character dots in the calculation of the character having the minimum width (half pitch) is 6.9, and the actual number of character dots is 7; The pitch error becomes 0.1 dots. That is, since the printing pitch error is one dot for the 10 characters having the minimum width, the accumulation counter 52 counts the characters having the minimum width as one unit.
Since the print pitch error has just reached one dot when the number of dots reaches 10 units or more, the correction operation of one dot may be performed. Then, as a result of such a print pitch correction operation, the corrected cumulative dot number is indicated as a corrected cumulative dot number A3. In addition, the part where the correction for one dot is performed is denoted by the symbol *. Tables 2 and 3 show that characters with different numbers of horizontal dots
Since it is shown in the same manner as in Table 1, its description is omitted.

FIG. 3 is an explanatory diagram of the dot structure of the ANK character. As shown in FIG.
Of the 4 dots, the area actually printed (print area) is 9
Dots are set, and on the right side, an unprinted area (margin area) indicated by oblique lines as a margin between characters is set to 5 dots. Therefore, FIG.
As shown in (b), there is no problem even if the first dot (print area) of the next character Cn + 1 overlaps with the 14th dot (margin area) of the character Cn during the correction operation. Note that even for characters other than the ANK character, a blank area of one dot or more is always set on the right side of the character, so that there is no problem due to the overlap of one dot.

FIG. 4 is a schematic flowchart of the printing process, FIG. 5 is a flowchart showing the printing pitch correction process, and FIG. 6 is a flowchart showing the error accumulating process. First, the schematic operation of the printing process will be described with reference to FIG. The CPU 2 of the printer 1 waits for print data and print command information transmitted from the host device 10 (step S1). When the print data and print command information are received, the CPU 2 analyzes the print command information and stores it in the buffer 51. It is stored (step S2). In this embodiment, the left margin is set in units of the pitch of the ANK character.

Then, it is determined whether or not one line of data, that is, print data and print command information has been received (step S3). If the result of this determination is negative ("N"), the process moves to step S1 and waits for data reception. On the other hand, if the determination result of step S3 is affirmative (“Y”), RA is determined according to the print command information.
An area for expanding print data is secured in a predetermined area of M5, and the received print data is expanded in the predetermined area one character at a time (step S4). Then, during the processing in step S4, the following print pitch correction processing and error accumulation processing are executed for each character.

When the developing process of step S4 is completed, the developed print data is sent to the printing unit 7 (step S4).
5) Printing is performed by the printing unit 7 (Step S)
6) The printing operation for one line is completed.

Next, the print pitch correction process and the error accumulation process will be described with reference to FIGS. The print pitch correction processing and the error accumulation processing are executed during the development of the print data in FIG. 4 described above (step S4) every time the development operation is performed for each character. First, referring to FIG. 5, the CPU 2 determines whether or not one line printing processing is being executed (step S10). If step S10 is negative ("N"), that is, if the processing of one line of print data is started, the accumulation counter 5
2 is initialized (cleared) (step S11). Next, the left margin amount stored in the buffer 51 is set in the LM pointer 53 in units of the number of dots (step S12). Then, it is determined whether or not the set left margin amount is 5 or more ANK characters, that is, whether or not the half-pitch character is 10 characters or more (step S1).
3). If step S13 is affirmative ("Y"), a printing pitch error of one dot occurs. Therefore, in order to correct the printing pitch, the value of the printing position start pointer 54 is decremented by one (step S14), and LM is also set. Pointer 53
1 (step S15).

Next, the process proceeds to an error accumulation process in step S16. In the error accumulation process, a process of converting the width included in the print data sent from the host device 10 into a print pitch error represented by a half-pitch character unit and accumulating the error is performed. Hereinafter, the error accumulation processing will be described with reference to the flowchart of FIG.

The character data sent from the host device 10 includes data indicating the number of dots in the width of the character data. In FIG. 6, it is determined whether or not the character data is a horizontally enlarged character (step S30). If this is affirmative (“Y”), it is determined whether or not the character data is a kanji (step S31). If this is affirmative, the kanji is equivalent to eight half-pitch characters, and the cumulative counter 52 is set to +8.
Then (step S32), the process returns. Step S3
If the answer is 1 (“N”), since the character is a horizontally enlarged character and corresponds to four half-pitch characters, the accumulation counter 52 is incremented by 4 (step S33), and the process returns. On the other hand, if negative ("N") in step S30, that is, if the character is not a horizontally enlarged character, it is determined whether or not it is a half-pitch double-width character (step S34).
Is incremented by 2 (step S35), and the process returns. If negative in step S34, it is determined whether or not the pitch is half pitch (step S36). If affirmative ("Y"), the accumulation counter 52 is incremented by one (step S37), and the process returns. If negative ("N") in step S36, it is determined whether or not the character is a normal ANK character (step S38). If affirmative, since the character is a normal ANK character, the accumulation counter 52 is incremented by 2 (step S39), and the process returns. If the determination in step S38 is negative ("N"), the accumulation counter 52 is incremented by 4 (step S40) because it is a double width of the ANK character.
To return.

Returning from the processing of FIG. 6 to step S17 of FIG. 5, it is determined whether or not the accumulation counter 52 has reached a value of 10 or more (step S17). If the determination result is affirmative ("Y"), the cumulative value of the print pitch error has reached one dot or more, so 10 is subtracted from the cumulative counter 52 (step S18), and the print start position pointer 54 is incremented by-. 1 to correct the printing pitch error (step S19), and return to step S3 in FIG. On the other hand, if negative ("N") in step S17, the process directly returns to step S3.

As described in detail above, according to the printing pitch correction method of the printer of this embodiment, the accumulated value of the printing pitch error is converted into the unit of the number of characters of the minimum width for each character and accumulated and held. In addition, when the accumulated value reaches a value of 10 characters or more, that is, when the print pitch error has just reached a value of 1 dot or more, the print start position pointer is decremented by one dot, thereby printing the print medium. By shifting the print position of the character data above by one dot, the error of the print pitch for one dot is corrected. Therefore, even if the number of character dots printed by the combination of the dot density of the print head and the character pitch has a fraction below the decimal point, the print pitch can be appropriately corrected. In addition, unlike the conventional method, there is no need to slow down the moving speed of the print head, so that there is no reduction in the print processing speed.

At the start of the one-line printing operation, it is determined whether or not the printing pitch error caused by the left margin amount set in the left margin pointer is a value of 1 dot or more. For example, since the print pitch error is corrected by subtracting one dot from the print start position pointer, the print pitch error due to the left margin can be appropriately corrected.

In the above-described embodiment, only the case where the error caused by the left margin amount is one dot has been described. However, if the print pitch error caused by the left margin amount is larger than one dot, The print pitch error may be corrected by subtracting the number of dots corresponding to the value obtained by rounding down the value after the decimal point from the print pitch error.

Further, the method of the present invention is applicable to a dot matrix type printer which prints one line at a time by moving the print head in the line direction, even if the type of the print head is an impact dot type or a thermal type. Can be widely applied.

[0036]

As described above in detail, according to the printing pitch correcting method for the linter of the present invention, the accumulated value of the printing pitch error is accumulated and held for each character, and the accumulated value is one dot. When the above value is reached, the printing start position pointer is subtracted by one dot, thereby shifting the printing position of the character data by one dot, thereby correcting the printing pitch error of one dot. . Therefore, even if the number of character dots printed by the combination of the dot density of the print head and the character pitch has a fraction below the decimal point, the print pitch can be appropriately corrected. In addition, unlike the conventional method, there is no need to slow down the moving speed of the print head, so that there is no reduction in the print processing speed.

At the start of the one-line printing operation, it is determined whether or not the printing pitch error caused by the left margin amount set in the left margin pointer is a value of 1 dot or more. For example, after the printing start position pointer is subtracted by one dot, the process proceeds to the error accumulation process. If the determination result is negative, the process directly proceeds to the error accumulation process. The printing pitch can be corrected for the pitch error.

When the cumulative value of the printing pitch error is converted to the minimum width character unit and handled, the printing pitch error is converted to the minimum width character unit and handled. No need to deal with errors,
There is an advantage that numerical processing is simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a printer that uses a print pitch correction method of the present invention.

FIG. 2 is an explanatory diagram showing the width of each character printed by a printer.

FIG. 3 is an explanatory diagram of a dot configuration of an ANK character.

FIG. 4 is a schematic flowchart of a printing process.

FIG. 5 is a flowchart illustrating a print pitch correction process.

FIG. 6 is a flowchart illustrating error accumulation processing.

[Explanation of symbols]

 1 Printer 5 RAM 51 Buffer 52 Cumulative Counter 53 Left Margin Pointer 54 Printing Start Position Pointer 10 Host Device

Claims (3)

[Claims] 1. A dot matrix printer which performs a printing operation by moving a print head in a row direction.
When the dot density of the print head indicated by the number of dots per unit dimension is Di, and the character pitch indicated by the number of characters to be printed per unit dimension is Cp, the number of dots required to print one character Is a printing pitch correction method for correcting a printing pitch error caused by a fractional part of a character dot number Cd (where Cd = Di / Cp) indicated by the following formula. An error accumulation process for accumulating and holding, one character at a time, a print pitch error determined by the width of a character specified by data; and determining whether the accumulated value of the print pitch error has reached a value of 1 dot or more. If the result of the determination is affirmative, the print start position pointer indicating the print start position of the print data on the print medium is decremented by one dot. Then, after subtracting one dot from the accumulated value of the printing pitch error, the process proceeds to the error accumulating process. If the determination result is negative, the printing pitch correction process returns to the error accumulating process. A print pitch correction method for a printer, wherein the method is repeatedly executed in units of one character during a period. 2. A print pitch error caused by a left margin amount set in a left margin pointer based on print command information sent from a higher-level device at the start of a one-line printing operation. If the determination result is affirmative, the printing start position pointer is subtracted from the printing pitch error by the number of dots corresponding to the value obtained by rounding down the value after the decimal point, and then the process proceeds to error accumulation processing. 2. The method according to claim 1, wherein if the answer is negative, the process directly proceeds to the error accumulation process. 3. The method according to claim 1, wherein the cumulative value of the print pitch error is converted to a minimum width character unit and handled.