JP2016087972A - Serial dot printer and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize printing according to a specified mode, at the same speed or quality as when using a first print head, even with a serial dot printer which uses a second print head in which one of the rows of pins is removed from the first print head where multiple pins are disposed in two rows in a staggered arrangement.SOLUTION: Provided is a method for controlling a serial dot printer using a second print head in which one of the rows of pins is removed from a first print head where multiple pins hitting an ink ribbon to print are disposed in two rows in a staggered arrangement. The method includes the steps of: receiving a specification of either a speed priority mode or a quality priority mode; printing with the second print head using a smaller number of dots than printing with the first print head, by applying a printing path as one path, in the case that the speed priority mode is specified; and printing with the second print head using the same number of dots as when printing with the first print head, by applying a printing path as two paths, in the case that the quality priority mode is specified.SELECTED DRAWING: Figure 19

Description

  The present invention relates to a serial dot printer and a control method thereof.

  There are known serial dot printers (dot impact printers) that perform printing by hitting a print head in which pins are arranged vertically and horizontally against an ink ribbon and making a mark of the shape of a character on paper with pressure (for example, Patent Documents 1 to 3). 5). At present, as a print head of a serial dot printer, a 24-pin print head having 24 pins arranged in a staggered manner in two rows is the mainstream. A printer equipped with a 24-pin printhead has a speed-priority DP (Draft Print) mode that prints 24 dots vertically x 12 dots horizontally, and a quality-first LQ that prints 24 dots vertically x 36 dots wide There is a (Letter Quality) mode. The serial dot printer performs printing by switching the carriage moving speed at a high speed when the DP mode is designated and switching the carriage moving speed at a low speed when the LQ mode is designated.

  On the other hand, there is an increasing demand for serial dot printers having a print head with a thin pin diameter capable of printing, for example, a two-dimensional barcode. Such a printer requires a low-cost print head that is smaller and lighter. A serial dot printer having a 9-pin print head is also known as a smaller print head than a 24-pin print head, but the existing 9-pin print head has a pin that can print a fine pattern such as a two-dimensional barcode. If the diameter is not thin and only the pin diameter is reduced, the characters cannot be constructed. Therefore, by removing 12 pins from the existing 24-pin print head, a small, lightweight and low-cost print head is constructed, and printing is equivalent to the 24-pin print head with two print passes, or the print pass is changed. It is conceivable to perform thinning printing with fewer dots than printing with a 24-pin print head as one pass.

Japanese Unexamined Patent Publication No. 01-218851 Japanese Patent Laid-Open No. 04-018376 JP 05-221029 A Japanese Patent Laid-Open No. 05-301378 JP 09-220820 A

  However, in the serial dot printer using the second print head having the pin arrangement in which the pins in one row are removed from the first print head in which the plurality of pins are arranged in a staggered manner in two rows, the print pass is 2 passes. In this case, printing can be performed with the same quality as the first print head, but the printing speed is lowered. If the printing pass is set to one pass, printing can be performed at the same speed as the first printing head, but the printing quality is lowered.

  Accordingly, an object of the present invention is to provide a serial dot printer using a second print head having a pin arrangement in which one row of pins is removed from the first print head in which a plurality of pins are arranged in a staggered manner in two rows. According to the designated mode, printing at a speed or quality equivalent to that when the first print head is used is realized.

Method for controlling a serial dot printer using a second print head having a pin arrangement in which a plurality of pins for printing by striking an ink ribbon are staggered in two rows and one of the rows of pins is removed The step of accepting the designation of either the speed priority mode or the quality priority mode, and when the speed priority mode is designated, the printing pass is set to one pass, and the number of dots is smaller than the printing by the first print head. A step of printing by the second print head, and a step of printing by the second print head with the same number of dots as the printing by the first print head when the quality priority mode is designated, with two print passes. There is provided a control method characterized by comprising:
In the above control method, the first print head is preferably a 24-pin print head and the second print head is preferably a 12-pin print head.
In the above control method, the speed priority mode is a draft printing mode in which each character is composed of 12 dots × 12 dots, and the quality priority mode is a letter quality mode in which each character is composed of 24 dots × 36 dots. Is preferred.

  A second print head having a pin arrangement in which a plurality of pins to be printed by hitting an ink ribbon are staggered in two rows and having a pin arrangement in which one row of pins is removed, speed priority mode and quality A receiving unit that accepts designation of any of the priority modes, and when the speed priority mode is designated, a printing pass is set as one pass, and printing is performed by the second print head with fewer dots than printing by the first print head. And a head control unit that causes the second print head to print with the same number of dots as the print by the first print head when the quality priority mode is designated and sets the print pass as two passes. A dot printer is provided.

  According to the present invention, even in a serial dot printer using a second print head having a pin arrangement in which one row of pins in the first print head in which a plurality of pins are arranged in a staggered manner in two rows is removed. Depending on the mode, it is possible to realize printing at the same speed or quality as when the first print head is used.

1 is a perspective view illustrating an appearance of a printer 100. FIG. 2 is a block diagram of a control unit 200 provided in the printer 100. FIG. It is a figure which shows the dot arrangement | sequence of 24 pin print head, and the dot structure of the character "H" printed. It is a figure which shows the dot arrangement | sequence of the 12-pin print head, and the dot structure of the character "H" printed. It is a figure which shows the dot structure of the character "H" for 24 pins in DP mode and LQ mode. It is a figure explaining 2 pass printing of character "H" for 24 pins in DP mode by a 12 pin print head. It is a figure explaining 2 pass printing of character "H" for 24 pins in LQ mode by a 12 pin printing head. FIG. 6 is a view similar to FIG. 5A and FIG. 5B for the 24-pin character “A”. It is a figure similar to FIG. 6 (A) and FIG. 6 (B) about the character "A" for 24 pins. It is a figure similar to FIG. 7 (A) and FIG. 7 (B) about the 24-pin character “A”. It is a figure which shows the dot structure of the letter "H" for 24 pins by which thinning printing was carried out by 12 pin print head in DP mode and LQ mode. It is a figure similar to FIG. 11 (A) and FIG. 11 (B) about the 24-pin character “A”. It is a figure explaining how to thin out dots by thinning printing. It is a figure explaining how to thin out dots by thinning printing. It is a figure explaining how to thin out dots by thinning printing. It is a figure which shows the dot structure of 24-pin character "I" and "P". It is a figure which shows the dot structure of the letter "I" for 24 pins thinly printed by the 12 pin print head in DP mode. It is the same figure as FIG. 17 (A) and FIG. 17 (B) about 24-pin character "P". 4 is a flowchart illustrating an example of a printing process performed by the printer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, it should be understood that the present invention is not limited to the drawings or the embodiments described below.

  FIG. 1 is a perspective view showing the external appearance of the printer 100. The printer 100 is a serial dot printer that performs printing by hitting a print head 106 in which pins are arranged vertically and horizontally against an ink ribbon, and making a mark of a character shape on a sheet with pressure.

  The printer 100 includes a substantially box-shaped housing 101. The casing 101 is provided with an operation unit 103 that receives an operation on the printer 100 on the front side when the printer 100 is used. The operation unit 103 is an example of a reception unit.

  An impact type printing unit 102 is provided inside the housing 101. The printing unit 102 includes a print head 106 and a platen 107. The paper and the ink ribbon are conveyed through between the print head 106 and the platen 107.

  The print head 106 is provided so as to reciprocate along a carriage guide shaft 104 provided inside the housing 101, and includes a plurality of bundled printing pins (wire pins). The carriage guide shaft 104 is provided with a direction (main scanning direction) perpendicular to the paper transport direction as an axial direction. As will be described later, a plurality of pins of the print head 106 are arranged in a line in the direction perpendicular to the axial direction (main scanning direction) of the platen 107 and can independently protrude toward the platen 107 side. It is configured.

  The platen 107 has a cylindrical shape whose axial direction is parallel to the carriage guide shaft 104, and faces the print head 106 over the entire reciprocating range of the print head 106. The platen 107 rotates with a transport roller (not shown) to apply a transport force to the paper on the paper transport path formed in the housing 101.

  A paper feed knob 105 is provided on the side surface of the housing 101. In the printer 100, the paper on the paper conveyance path can be manually conveyed by operating the paper feed knob 105 and rotating the platen 107.

  At the time of printing, the printing unit 102 selectively hits a plurality of wire pins provided in the print head 106 against the platen 107 in a state where the paper and the ink ribbon are interposed between the print head 106 and the platen 107. Put a small dot (dot) in The printing unit 102 represents characters and the like by continuously ejecting dots in this way. Note that “printing” as used in this specification includes not only the case where a character is represented by a printed dot but also the case where a character other than a character such as a figure is represented.

  FIG. 2 is a block diagram of the control unit 200 provided in the printer 100. The printer 100 includes a control unit 200 inside a housing 101, and the control unit 200 includes a CPU 201, a ROM 202, a RAM 203, a wire control unit 204, a head drive motor 205, and a paper transport motor 206.

  The CPU 201 is an example of a data processing unit, and controls the overall operation of the printer 100. The ROM 202 stores programs necessary for the operation of the printer 100 such as a boot program. A RAM 203 is a storage area used as a work area of the CPU 201, and is used as a buffer when developing a dot pattern based on print data, for example.

  The wire control unit 204 selectively energizes elements corresponding to a plurality of wire pins provided in the print head 106 based on a control signal from the CPU 201, and causes the corresponding wire pins to protrude toward the platen 107. The wire control unit 204 is an example of a head control unit. The head driving motor 205 generates a driving force that reciprocates the print head 106 in the main scanning direction. The paper transport motor 206 generates a driving force for transporting the paper in a direction perpendicular to the main scanning direction.

  During printing, the CPU 201 selectively drives the pins included in the print head 106 toward the platen 107 while reciprocating the print head 106 in the main scanning direction by rotating the head drive motor 205. Further, the CPU 201 conveys a sheet in a direction perpendicular to the main scanning direction by rotating and driving a sheet conveying motor 206.

  Printing by the printer 100 is performed line by line by selectively projecting pins while moving the print head 106 in the main scanning direction. This control is performed by the CPU 201 executing a control program stored in the ROM 202 while using the RAM 203 as a work area.

  FIGS. 3A and 3B are diagrams showing a pin arrangement of a 24-pin print head and a dot configuration of a character “H” to be printed, respectively. FIGS. 4A and 4B are diagrams showing a pin arrangement of a 12-pin print head and a dot configuration of a character “H” to be printed, respectively. The 24-pin print head is an example of a first print head, and the 12-pin print head is an example of a second print head.

  In the 24-pin print head shown in FIG. 3A, a total of 24 pins for printing by hitting an ink ribbon are arranged in a staggered manner in two rows. The right column in the figure has 12 pins numbered 1, 3, 5,..., 23, and the left column in the figure has numbers 2, 4, 6,. Twelve attached pins are arranged respectively. Hereinafter, for convenience, the odd-numbered pins in the right column in FIG. 3A are referred to as “odd pins”, and the even-numbered pins in the left column in FIG. This is called “even pin”. When the print head is attached to the printer, the odd-numbered pin rows and the even-numbered pin rows are shifted in the main scanning direction, and the pins in each row are arranged in a direction (sub-scanning direction) perpendicular to the main scanning direction. . 3A to 18B, the horizontal direction corresponds to the main scanning direction, the axial direction of the platen 107 and the carriage guide shaft 104, and the transport direction of the ink ribbon and the print head. The vertical direction corresponds to the sub-scanning direction and the paper transport direction. As an example, the interval between rows of odd and even pins is 18/360 inches, and in the case of 120 dpi, it corresponds to 6 dots. Moreover, the pin diameter of each pin is 0.2 mm, for example.

  On the other hand, the 12-pin print head shown in FIG. 4A has a pin arrangement in which the even-numbered pins (pins in one row) in the 24-pin print head are removed, and the odd-numbered pins (in the other row) in the 24-pin print head. Only twelve pins corresponding to the first pin are arranged in one row. The printer 100 shown in FIG. 1 has a 12-pin print head shown in FIG.

  The letter “H” shown in FIG. 3B is composed of 24 dots vertically × 12 dots horizontally. In this figure and each figure shown thereafter, dots to be printed are indicated by “●”, and dots not to be printed are indicated by “•”. When a 24-pin print head is used, dots in an array corresponding to the print data are printed by the corresponding pins for each of the 24 columns numbered 01 to 24. On the other hand, the letter “H” shown in FIG. 4B is composed of 12 dots vertically × 12 dots horizontally. When using a 12-pin print head, the even pins in the 24-pin print head have been removed (thinned out), so each of the 12 columns numbered 01, 03, 05,. , Dots corresponding to the print data are printed by the corresponding pins.

  The printer 100 prints 24-pin characters with the same number of dots as the printing by the 24-pin print head (hereinafter referred to as “2-pass”) with two print passes according to the mode designated via the operation unit 103. Printing ”) and printing of characters for 24 pins with a smaller number of dots than printing by a 24-pin print head (hereinafter referred to as“ 1 pass printing ”or“ decimated printing ”). Do something. Hereinafter, two-pass printing and thinning printing will be described in order.

  FIGS. 5A and 5B are diagrams showing dot configurations of the 24-pin character “H” in the DP mode and the LQ mode, respectively. FIG. 6A and FIG. 6B are diagrams illustrating 2-pass printing of the 24-pin character “H” in the DP mode by the 12-pin print head. FIGS. 7A and 7B are diagrams illustrating 2-pass printing of the 24-pin character “H” in the LQ mode by the 12-pin print head.

  The characters in the DP mode shown in FIG. 5A are composed of 24 dots vertically × 12 dots horizontally. In the case of two-pass printing, first, as shown in FIG. 6A, dots assigned to odd pins of a 24-pin print head are printed in the first printing pass. Next, at the time of the second printing pass, the sheet conveying motor 206 is perpendicular to the main scanning direction by a distance (for example, 1/180 inch) corresponding to the interval between even and odd pins in which the numbers in the arrangement direction of the pins are continuous. A small amount of paper is conveyed in the direction. As a result, when a 24-pin print head is attached instead of the 12-pin print head, the print portion of the paper is aligned with the position where the even-numbered pins are present. Thereafter, in the second printing pass, as shown in FIG. 6B, dots assigned to the even pins of the 24-pin print head are printed. As a result, the character finally obtained in the two printing passes is the same as the character printed by the 24-pin print head shown in FIG.

  The characters in the LQ mode shown in FIG. 5B are composed of 24 dots vertically × 36 dots horizontally. Also in the LQ mode, the carriage moving speed is lower than in the DP mode, and the number of dots in the horizontal direction in each of the first and second printing passes is increased, and the printing method is in the DP mode. It is the same. That is, odd-numbered dots are printed in the first printing pass, and the paper is conveyed by a distance corresponding to the even-odd pin interval, and then even-numbered dots are printed in the second printing pass. As a result, the character finally obtained in the two printing passes is the same as the character printed by the 24-pin print head shown in FIG.

  FIGS. 8A to 10B are views similar to FIGS. 5A to 7B for the 24-pin character “A”, respectively.

  As described above, by performing 2-pass printing, even if the 24-pin print head is replaced with a 12-pin print head, the same number of dots are printed as the 24-pin print head, so the print quality is equivalent to the 24-pin print head. Can be realized. However, in 2-pass printing, the printing speed is reduced to less than half compared to the case of a 24-pin print head, and the time required for printing is approximately doubled.

  FIGS. 11A and 11B are diagrams showing the dot configuration of the 24-pin character “H” thinned out by the 12-pin print head in the DP mode and the LQ mode, respectively. FIGS. 12A and 12B are views similar to FIGS. 11A and 11B for the 24-pin character “A”, respectively.

  In the case of thinning printing, the printing pass is one pass, and a character is formed only by the first printing pass in the two-pass printing. For this reason, the dot configuration of the DP mode character “H” that has been thinned and printed as shown in FIG. 11A is the DP mode at the time when the first printing pass in the two-pass printing shown in FIG. Is substantially the same as the dot configuration of the letter “H”. In addition, the dot configuration of the LQ mode character “H” that has been thinned and printed as shown in FIG. 11B is the same as that in the LQ mode when the first printing pass in the two-pass printing shown in FIG. This is almost the same as the dot configuration of the letter “H”. However, in the thinning printing by the printer 100, the print data for the 12-pin print head is generated by a method described later for the purpose of suppressing the deterioration of printing quality. The dot configuration in one pass in printing is not completely the same. This print data generation method (dot thinning method) will be described later.

  By performing decimation printing, even if the 24-pin print head is replaced with a 12-pin print head, printing is performed in the same one pass as the 24-pin print head, so a printing speed equivalent to that of the 24-pin print head can be realized. . However, in the thinning printing, the number of printing dots is reduced to about half compared with the case of the 24-pin print head, so that the printing quality is deteriorated. Therefore, as will be described later, the printer 100 allows the user to select whether to give priority to speed or quality.

  If only the first half of numbers 1 to 12 is left out of the 24 pins in the 24-pin print head and the pins 13 to 24 are removed to form a 12-pin print head, thinning printing cannot be realized. As shown in FIG. 4A, for example, thinning-out printing can be realized by thinning even-numbered pins and configuring a 12-pin print head leaving odd-numbered pins. In contrast to the pin arrangement shown in FIG. 4A, the odd-numbered pins may be thinned out and the even-numbered pins may be left to form a 12-pin print head.

  FIGS. 13A to 15E are diagrams for explaining how to thin out dots by thinning printing. When thinning printing is performed using a 12-pin printing head with even-numbered pins as shown in FIG. 4A, the even-numbered pins in the 24-pin printing head are used in order to suppress deterioration in printing quality. It is preferable to print the assigned print dots with odd pins adjacent to the even pins. Therefore, in thinning printing by the printer 100, print data for a 12-pin print head is generated in the following procedure.

  FIGS. 13A to 14B show a print data generation procedure when the 24-pin character “A” is thinned out in the DP mode. FIG. 13A shows an original dot configuration printed by a 24-pin print head.

  First, for each dot corresponding to each odd-numbered pin, the control unit 200 calculates the logical sum (OR) of the dot print data and the dot print data corresponding to the even-numbered pins adjacent to the dot. FIG. 13B shows a dot configuration of the print data shown in FIG. 13A when the logical sum of the print data of the odd-numbered dots and the print data of the adjacent even-numbered pins is taken. As described above, the printer 100 performs interpolation by printing the print dots assigned to the even pins with the odd pins. The control unit 200 stores the obtained data in the RAM 203 as print data for odd pins.

  FIG. 15A shows an example of how to take this logical sum. In this example, as indicated by “●” on the left side of the drawing, the dots in the third row of the odd pins 01 and the even pins 02 are the dots to be printed. Therefore, the logical sum of the dots in the third row of the odd-numbered pins 01 is taken with the dots in the third row of the even-numbered pins 02 adjacent to the dots, and the dots in the third row of the odd-numbered pins 01 are printed.

  FIG. 15B shows another example of a logical sum. In this example, as indicated by “●” on the left side of the drawing, only the dots in the third row of even-numbered pins 02 are dots to be printed. Therefore, the logical sum of the dots in the third row of the odd pins 01 and the dots in the third row of the even pins 02 adjacent to the dots is taken. As a result, the dots in the third row of the odd-numbered pins 01 that were not originally dots to be printed are changed to dots to be printed. By taking the logical sum in this way, even-numbered dots that disappear due to thinning-out printing are supplemented by odd-numbered pins.

  When the logical sum is obtained, the even-numbered pin print data becomes unnecessary, and the control unit 200 clears the even-numbered pin print data stored in the RAM 203. FIG. 14A shows the dot configuration when the print data of even pins is cleared for the print data shown in FIG. In FIG. 14A, dots with clear print data are indicated by “x”. However, the control unit 200 may leave the print data of the even pins not cleared until the next print data is acquired.

  Subsequently, the control unit 200 performs a mask process on the print data of odd-numbered pins so that print dots by the same pins do not continue. This is a process performed because two dots cannot be continuously hit with the same pin due to the responsiveness of the print head, and is called a half-dot mask process. That is, a dot adjacent in the left-right direction of one printing dot is a dot that is not necessarily printed. FIG. 15E is a diagram for explaining half-dot mask processing. In the printer 100, the dots printed by the same pin do not continue as shown by “●” on the left side in the figure, and the dot next to one print dot by the same pin is a half dot as shown on the right side in the figure. It is changed to a dot that is not always printed by mask processing. FIG. 14B shows a dot configuration when half-dot mask processing is performed on the print data shown in FIG.

  FIG. 15C shows still another example of how to take a logical sum. In this example, as indicated by “●” on the left side of the drawing, the dots in the fourth row of odd pins 01 and the dots in the third row of even pins 02 are dots to be printed. Therefore, the logical sum of the dots in the third row of the odd pins 01 and the dots in the third row of the even pins 02 adjacent to the dots is taken. As a result, the dots in the third row of the odd-numbered pins 01 are changed to dots to be printed. However, in this case, the dots are consecutive in the third and fourth rows of the odd-numbered pins 01. Therefore, the control unit 200 clears, for example, changes the dots in the fourth row of the odd pins 01 to dots that are not printed by half-dot mask processing. Thus, in the example of FIG. 15C, only the dots in the third row of the odd-numbered pins 01 are the dots to be printed.

  Then, based on the print data that has been subjected to the half-dot mask process, the control unit 200 controls the 12-pin print head to execute thinning printing.

  When the logical sum is taken for the dot whose next dot is a print dot as in the example of FIG. 15C, the print dot on the odd-numbered pin 01 moves left and right by the logical sum and half-dot mask processing. (The printed dots on the odd-numbered pins 01 move from the fourth row to the third row). Therefore, the control unit 200 may not perform a logical sum for a dot whose next dot is a print dot, but may perform a logical sum only for a dot whose next dot is not a print dot. That is, the control unit 200 may calculate the logical sum of the print data of the dot and the print data of the dot corresponding to the even pin adjacent to the dot for the dot that is not the print dot as the next dot corresponding to the same odd pin. .

  FIG. 15D shows still another example of how to take a logical sum. In this example, as indicated by “●” on the left side of the drawing, the dots in the fourth row of odd pins 01 and the dots in the third row of even pins 02 are dots to be printed. Regarding the dots in the third row of the odd-numbered pins 01, the dots in the next fourth row are print dots. Therefore, in this example, the control unit 200 does not perform an OR operation on the dots in the third row of the odd-numbered pins 01 and the dots in the third row of the even-numbered pins 02. Even so, the dots in the third row of the odd-numbered pins 01 are not printed. In the example of FIG. 15D, the print data of the even pins is cleared, so that only the dots in the fourth row of the odd pins 01 are the dots to be printed. In this way, the odd-numbered print dots do not move left and right due to the logical sum and half-dot mask processing.

  In the first method of taking the logical sum described with reference to FIGS. 15A to 15C, regardless of whether the next dot corresponding to the same odd pin is a print dot or not, the odd pin is used. For each corresponding dot, the logical sum of the dot print data and the dot print data corresponding to the even pins adjacent to the dot is taken. On the other hand, in the second method of taking the logical sum described with reference to FIG. 15D, the logical sum is taken only for the dot that is not the print dot as the next dot corresponding to the same odd pin. Which of the first method and the second method is better for viewing the printed characters may differ depending on the font of the characters.

  FIGS. 16A and 16B are diagrams showing dot configurations of 24-pin characters “I” and “P”, respectively. In the following, taking these characters as examples, the first method and the second method are compared with respect to the appearance of the printed characters.

  FIGS. 17A and 17B are diagrams showing the dot configuration of the 24-pin character “I” thinned out by the 12-pin print head in the DP mode, respectively. Of these, FIG. 17A shows the print result based on the print data obtained by ORing with the first method and FIG. 17B with the second method shown in FIG. 17B. As can be seen from a comparison between FIG. 17A and FIG. 17B, in the first method, the print dots are uniformly arranged as a whole to form the character “I”. In this case, the number of print dots on the upper side and the lower side of the character is different, and the character “I” that should be symmetrical vertically is asymmetric. Therefore, it is preferable to generate print data for the character “I” by the first method.

  FIGS. 18A and 18B are views similar to FIGS. 17A and 17B for the 24-pin character “P”, respectively. Of these, FIG. 18A shows the print result based on the print data obtained by performing the logical sum by the above-mentioned first method, and FIG. 18B by the above-mentioned second method. As can be seen by comparing FIG. 18 (A) and FIG. 18 (B), the first method has a dot arrangement in which the curved portion of the letter “P” looks sharp, but in the second method, Print dots are arranged so that the curved portion looks smooth. Therefore, it is preferable to generate print data for the character “P” by the second method.

  As described above, the printer 100 selects in advance whether to use the first method or the second method to perform the logical sum of the print data for each character font, and stores the information in, for example, the ROM 202. deep. Then, the control unit 200 refers to the information at the time of thinning-out printing, calculates a logical sum of the print data in accordance with either the first method or the second method, and performs 12-pin processing based on the print data. Controls printing by the print head.

  In selecting the first method and the second method, the characters thinned and printed using the first method and the characters thinned and printed using the second method are used, for example, for all characters. The user may determine which method is better by printing at 100, and allow the user to input the result via the operation unit 103. In addition, for each character set such as alphanumeric characters and kanji characters, for example, it may be possible to select in advance whether to use the first method or the second method to perform logical OR of the print data. .

  Next, automatic selection between 2-pass printing and thinning printing by the printer 100 will be described. In the printer 100, the user can input designation of either the DP mode (speed priority mode) or the LQ mode (quality priority mode) via the operation unit 103. When the DP mode is designated, the control unit 200 executes thinning printing in which each character is composed of 12 dots × 12 dots. On the other hand, when the LQ mode is designated, the control unit 200 executes 2-pass printing in which each character is composed of 24 dots × 36 dots. That is, in the DP mode in which the horizontal dots are low in density, the vertical dots are also thinned out to be low in density, and in the LQ mode in which the horizontal dots are high in density, the vertical dots remain high in density. As described above, the control unit 200 executes two-pass printing in the LQ mode where high print quality is required, and executes one-pass printing (decimation printing) in the DP mode in which speed is important. Thinning printing is automatically switched between 1-pass and 2-pass. Thereby, in the printer 100, the print quality and the print speed are optimized according to the user's request.

  Note that the user may be able to select DP mode two-pass printing, LQ mode two-pass printing, DP mode thinning printing, and LQ mode thinning printing via the operation unit 103.

  FIG. 19 is a flowchart illustrating an example of print processing by the printer 100. The flow shown in FIG. 19 is executed by the CPU 201 in the control unit 200 according to a program stored in advance in the ROM 202 in the control unit 200.

  First, the control unit 200 determines which one of the LQ mode and the DP mode is designated by the user (step S10). If the LQ mode is designated, the process proceeds to step S20 to perform two-pass printing, and if the DP mode is designated, the process proceeds to step S30 to perform thinning printing.

  In the two-pass printing, the control unit 200 first controls the 12-pin print head in the first printing pass to print the dots assigned to the odd-numbered pins of the 24-pin characters (step S20). Then, the control unit 200 causes the paper transport motor 206 to transport the paper minutely in the direction perpendicular to the main scanning direction by a distance corresponding to an even / odd pin interval (for example, 1/180 inch), thereby achieving a 12-pin print head. Instead, when the 24-pin print head is attached, the print portion of the paper is aligned with the position where the even pins are present (step S21). Then, in the second printing pass, the control unit 200 controls the 12-pin print head to print the dots assigned to the even pins of the 24-pin characters (step S22). Thereby, the printing process by two-pass printing is completed.

  On the other hand, in thinning printing, for each dot corresponding to each odd-numbered pin, the control unit 200 performs a logical sum (OR) of the dot print data and the dot print data corresponding to the even-numbered pin adjacent to that dot. (Step S30). The logical sum can be obtained by either the first method or the second method described above. Then, the control unit 200 uses the obtained data as the odd-numbered pin print data, and clears the even-numbered pin print data (step S31). Further, the control unit 200 performs half-dot mask processing on the print data of the odd pins so that the print dots of the same pins do not continue (step S32). Then, based on the print data subjected to the half-dot mask process, the control unit 200 controls the 12-pin print head to execute thinning printing (step S33). Thereby, the printing process by thinning-out printing ends.

  In the printer 100, the following effects can be obtained by using a 12-pin print head having a pin arrangement of only odd-numbered pins in which even-numbered pins of the 24-pin print head are thinned out. First, compared with a 24-pin printhead, the printhead is reduced in size and weight, noise is reduced, and the power supply and driver circuit are reduced in cost. By performing two-pass printing, printing with the same quality as that of a 24-pin print head can be performed, and by performing thinning printing, printing at the same speed as that of a 24-pin print head can be performed. .

  Further, in the printer 100, since the print head is reduced in size and weight, the printer itself can be reduced in size and weight. However, as shown in FIG. 4B, by removing one row of pins in the existing 24-pin print head to form a 12-pin print head, the printer mechanism for the 24-pin print head can be used as it is. It is also possible to create a printer with a 12-pin print head. Further, in the printer 100, since the pin system of the print head is sufficiently thin as 0.2 mm, it is possible to print a two-dimensional barcode.

DESCRIPTION OF SYMBOLS 100 Printer 101 Case 102 Printing part 103 Operation part 104 Carriage guide shaft 105 Paper feed knob 106 Print head 107 Platen 200 Control part 201 CPU
202 ROM
203 RAM
204 Wire control unit 205 Head drive motor 206 Paper transport motor

Claims (4)

Method for controlling a serial dot printer using a second print head having a pin arrangement in which a plurality of pins for printing by striking an ink ribbon are staggered in two rows and one of the rows of pins is removed Because
Receiving a designation of either speed priority mode or quality priority mode;
When the speed priority mode is designated, a printing pass is set as one pass, and printing is performed by the second print head with a smaller number of dots than printing by the first print head;
When the quality priority mode is designated, printing with the second print head with the same number of dots as the printing with the first print head, with two print passes;
A control method characterized by comprising: The first print head is a 24-pin print head;
The control method according to claim 1, wherein the second print head is a 12-pin print head. The speed priority mode is a draft printing mode in which each character is composed of 12 dots × 12 dots,
The control method according to claim 2, wherein the quality priority mode is a letter quality mode in which each character is composed of 24 dots × 36 dots. A second print head having a pin arrangement in which one row of pins in the first print head in which a plurality of pins for printing by hitting an ink ribbon are staggered in two rows is removed;
A reception unit that accepts designation of either speed priority mode or quality priority mode;
When the speed priority mode is designated, the print pass is set as one pass, printing is performed by the second print head with a smaller number of dots than the printing by the first print head, and the quality priority mode is designated. And a head control unit that causes the second print head to print with the same number of dots as the print by the first print head, with two print passes.
A serial dot printer comprising:

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