JPH0526400U - Printer device - Google Patents

Abstract

(57) [Abstract] [Purpose] When the dot pattern is overlaid and high density printing is obtained, the back gap between the gears is used to feed the paper 5 a minute distance from the step motor 6 through the gears 7 and 8. The drive amount of the step motor 6 is set in consideration of the influence of rush. [Structure] A driving force of a step motor 6 is transmitted to a platen 1 of a printer, which conveys printing paper, through a drive gear 7 and a platen gear 8. The step motor 6 drives the paper feed in units of the inter-dot distance of the serial dot print head 4 divided into integer m of 3 or more. During high-density printing work, after the normal printing process, it is smaller than m,
Also, the paper is fed in units of integer n which is larger than m / 2, and at this time, the same pattern data as the dot pattern in the first normal printing or different pattern data is output to the print head 4 for printing. To do.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a serial dot printer device for performing high-density printing, and more particularly, to a device that enables high-density printing rather than a dot matrix type printer device.

[0002]

[Prior Art]

 For example, in a dot matrix printer, the print head mounted on the carriage is placed facing the print paper, and the carriage is reciprocated in the width direction of the print paper at right angles to the paper feed direction (line feed direction). To configure. When printing with the appropriate number of characters (character digits) in the printable area of one line, the print timing signal from the carriage control unit is sent during the movement of the serial print head (digit feed, feed in the print paper width direction). The print pattern data at the current position is received, sent from the print control unit to the print head drive unit, and the print head is driven in a predetermined pattern to print one character at a time.

In this case, for example, when printing with a dot matrix of 7 × 9 dots per character, as shown in FIG. 5, nine lines arranged at regular intervals (P1) in the vertical direction (paper feed direction). The carriage drive motor is operated so as to feed the 9-pin dot print head 100 equipped with the print wire 101 of FIG. 1 at an appropriate interval (S1) in the column feed direction perpendicular to the paper feed. In order to obtain high quality printing, it is easy to increase the printing density (dot density) in the lateral direction of characters by finely setting the carriage shift interval (S1) by the carriage drive motor. However, as described above, the vertical spacing of the print wires 101 in the print head 100 is structurally restricted by the diameter of the print wires and the size of the guide portion that slidably supports each print wire. , It is not easy to increase the vertical print density (dot density) of characters.

In order to solve this problem, in Japanese Patent Laid-Open No. 52-110117, a printing wire is arranged at a distance twice as large as a dot interval of a dot pattern of a character to be printed, and after the first printing step is completed. Paper feed is executed for a distance of 1 dot, and another dot pattern different from the 1st dot pattern data printed in the 1st printing process is printed at this position. It is proposed to print one character that becomes a dot pattern.

Further, in Japanese Examined Patent Publication No. 1-49632, as a control for emphasizing a character shape rather than a normal print shape, a print head in which a print wire array is arranged at a distance of one dot in accordance with dot pattern data. And a paper feed mechanism that feeds the inter-dot distance by a pulse of an integer of 3 or more m, wherein the paper feed mechanism is provided with n less than half of the m after the normal printing process. It is proposed that the process of sending out (integer) pulses and feeding the paper is executed, and at this time, printing is performed with the same dot pattern data as the dot pattern in the previous normal printing process.

[0006]

[Problems to be solved by the device]

 In the technique of this prior art (Japanese Patent Publication No. 1-49632), since the second printing dot is positioned after being shifted by an interval smaller than half the printing dot interval printed in the first printing process, Since the same character pattern overlaps vertically with a distance of 1/2 dot or less, it is printed at a higher density than a normal character, and is said to be stronger than other characters.

By the way, in the case of the paper feeding mechanism configured to rotate the platen from the paper feeding step motor via the gear train, there are the following problems. That is, there is a so-called backlash (play between tooth flanks) t between the tooth flanks of the driving gear 102 and the driven gear 103 that mesh with each other in the gear train due to manufacturing tolerances and the like. Then, as shown in FIG. 6A, when the intermittent rotation speed of the platen corresponding to the line feed speed (paper feed speed) is small, the paper feed step motor is stopped, and is rotated in the direction of arrow A and then stopped. The front side (driving force transmitting side surface) of the tooth surface of the drive-side gear 102 stops in a state of being in contact with the rear surface of the tooth surface of the driven-side gear 103. Therefore, the backlash t exists between the rear surface of the tooth surface of the driving gear 102 and the front surface of the tooth surface of the driven gear 103. However, if the intermittent rotation angle of the platen is large, the speed becomes large, and even if the drive-side toothed gear 102 is stopped by stopping the paper feed step motor, the driven-side gear is driven by the rotational inertia of the platen. 103 rotates (forwards) by the gap of the backlash t and stops (see FIG. 6B). When the paper feed step motor is operated after such a stop, unless the drive side gear 102 is additionally rotated (advanced) by the gap of the backlash t, the driven side gear 103, and thus the platen are rotated. You will not be able to start.

As described above, when the control for sending the print paper in the paper feed direction by a minute distance shorter than the dot interval is executed through the gear train transmission mechanism having such backlash, the backlash is about 0.1, for example. However, assuming that the minute distance feed amount in the paper feed direction is 0.117 mm, even if the step pulse corresponding to the minute distance feed amount is output to the paper feed step motor, The platen practically does not rotate because it is offset by the rush. Therefore, the higher the printing speed, the greater the influence of the backlash, and there is a problem in that the first and second printing patterns overlap, and beautiful high quality characters cannot be printed.

In order to avoid this, it is necessary to set the backlash to 0 or to set the same backlash amount in both one line feed and half-pitch paper feeding. The feed rate becomes extremely slow, and in the latter case, a large amount of electric power and torque are required at the time of half-pitch feed, so neither is practical. The problem caused by such backlash has not been taken into consideration or solved even in the technique disclosed in Japanese Patent Laid-Open No. 52-110117.

An object of the present invention is to provide a printing device that solves this technical problem.

[0011]

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a paper feed mechanism for transferring printing paper, the paper feed mechanism is connected to the paper feed mechanism via a gear train, and the distance between dots is 3 or more. In a printer device equipped with a drive mechanism for driving to feed paper in units divided into integers m, the paper is fed in units of integer n smaller than m and larger than m / 2, and At this time, a control means for outputting arbitrary dot pattern data to the print head is provided.

[0012]

【Example】

 Next, an embodiment embodying the present invention will be described. In FIG. 1, reference numeral 1 is a platen in a serial printer, and reference numerals 2 and 3 are auxiliary rollers abutting on the outer peripheral surface of the platen 1. A serial dot type print head 4 in which nine print wires are vertically arranged is mounted on a carriage (not shown) so as to face the outer peripheral surface of the platen 1. The carriage is mounted on the platen 1 by a step motor (not shown) and a timing belt. It is configured to be capable of reciprocating along the longitudinal direction (width direction of paper). The ink ribbon housed in the ribbon cassette is arranged between the print paper 5 wound around a part of the outer circumference of the platen 1 and the front surface of the print head 4, and selectively protrudes from the front surface of the print head 4. The ink of the ink ribbon is imprinted on the printing paper 5 with the tip of the moved printing wire to perform dot printing.

Then, power is transmitted from the drive gear 7 attached to the step motor 6 to the platen gear 8 to rotate the platen 1. The pitch circle diameter of the platen gear 8 is formed to be substantially the same as the diameter of the platen 1. A second gear 9, a third gear 10 and a fourth gear 11 are sequentially meshed and connected to the platen gear 8, and the driving force of the step motor 6 is decelerated and transmitted from the fourth gear 11 to the transmission shaft 13 of the pin tractor 12. .. Pins 14 protruding from the outer peripheral surface of the belt of the pin tractor 12 at regular intervals are engaged with feed holes 15 formed on both left and right edges of the printing paper 5 to transfer the printing paper 5 (paper feeding). To do.

FIG. 2 shows a functional block diagram of the microcomputer in the controller section of the printer. Reference numeral 16 is a central processing unit (CPU), and reference numeral 17 is a data exchange with a host computer 50 as a host device. Reference numeral 18 is an interface for transmitting and receiving data, and a reference numeral 18 is a read-only character generator in which character patterns of commonly used kanji such as first level kanji and second level kanji and a character code designating the same are stored in advance. (Character generator).

The character generator 18 includes a first part 18a for generating fonts of draft characters and a second part 18b for generating data of even-numbered pins (0, 2, 4, 6, 8) of high-density characters. And a third portion 18c which similarly generates data for odd-numbered pins (1, 3, 5, 7, 9). Reference numeral 19 represents a read-only non-Kanji character generator in which non-Kanji characters such as letters, numbers, hiragana characters, and Katakana characters are stored in advance, and reference numeral 20 is for controlling the operation of the mechanical portion of the printer. It is a work memory that can read and write the control signal of.

Reference numeral 21 is a readable / writable memory for writing and storing image data such as an image sent from the host computer 50 in response to an image print command, and reference numeral 22 can be additionally added if desired by the user. It is an optional memory, a readable / writable registration memory, and the memories 20, 21 and 22 are electrically erasable / writable non-volatile memories (EEPROMs), and can retain the stored contents even when the main power is turned off.

A reference numeral 23 calls a predetermined character or image from the character generators 18 and 19 and other memories 21 and 22 according to a command from the central processing unit 16, and converts the character into vertical writing or horizontal writing. An IC (gate array) for processing print data for writing, 24 is a nonvolatile memory (EEPROM) in which data for fine adjustment according to the mechanism of the printing unit can be written, reference numeral 25 is a memory of the interface 17 It is a printing processing IC that switches the mode, fonts of characters, high-density printing, or draft printing.

Reference numeral 26 is an IC (gate array) that controls a print data memory (print buffers 27 and 28) that constitutes a duty counter or the like for controlling the printing timing and the like. The two-line print buffers 27 and 28 for temporarily storing the character data of one line on the paper respectively are based on the data accumulated in the print buffer 27 of one of them, and the print buffer 28 of the other is operated during the printing operation of one line. By storing the character data of the next line, the bidirectional printing work can be executed quickly.

Reference numeral 29 is an IC (gate array) for controlling the serial dot print head drive circuit 30, which instructs the print head 4 to output data of dot pins to the print head drive circuit 30. Further, reference numeral 32 is a limit switch for stopping the printing operation and paper feeding by sensing that the paper is exhausted, reference numeral 33 is a paper feeding, an alarm drive circuit for giving a warning with a buzzer when the absence of paper is detected, and a reference numeral 34 is printing. It is a fan drive circuit for driving the fan for cooling the inside of the equipment, and is related to the on / off of the power switch.

Reference numeral 35 is a motor drive circuit for driving the carriage drive motor 9 for moving the carriage in the forward printing direction and the reverse printing direction, and reference numeral 36 is for counting the number of rotations of the carriage driving motor 9. An encoder, reference numeral 37, is a paper feed motor drive circuit for driving the step motor 6 that vertically feeds (row feeds) the paper 15. The paper feed motor drive circuit 37 outputs a drive signal for feeding the paper in units (drive pulses) in which the one-dot distance P 1 in the line feed direction is divided into an integer m of 3 or more. Then, when performing a high-density printing operation to be described later, after performing the first normal printing operation for one line by the data from the second portion 18b of the character generator, A drive signal is output from the paper feed motor drive circuit 37 so as to execute minute paper feed in units of n (m> n> m / 2) (drive pulse) larger than m / 2. At this time (during the second printing step), the predetermined printing dot pattern data (data from the third part 18c of the character generator) different from the printing dot pattern at the first printing step is used as the character. It is controlled so that it is read from the sources 18 and 19 and output to the print head 4.

In the embodiment, the value of the backlash t between the platen gear 8 and the drive gear 7 having the pitch circle diameter substantially equal to the diameter of the platen 1 is 0.1 mm, and the interval of 1 dot in the line feed direction is It is assumed to be 1/72 inch (about 0.352 mm). The first printing process is executed by supplying a drive signal corresponding to an integer (m = 3) drive pulse from the paper feed motor drive circuit 37 to the step motor 6. Therefore, the paper is fed every 1/216 inch (about 0.1175 mm) by this one-pulse drive signal. The print dot pattern at this time is a normal print character pattern. An example of the character pattern is shown by a 7 × 9 dot printing pattern for the character “N”, which is a white circle in FIG.

Then, in the second printing step, the value of n is set to 2, and a drive signal corresponding to two pulses is given to (1/72) × (2/3) = 2/216 inch ( The stepping motor 6 is intermittently rotated by about 0.235 mm) to feed the paper, and printing is performed with the same print dot pattern as in the first printing step, which is double-printing. The shaded circle in Fig. 3 is the second print, and together with the white circle in Fig. 3, it is a double-strike print sample as a whole.

In FIG. 4, regarding the character “K”, the first print dot pattern (shown by a white circle) and the second print dot pattern (shown by a shaded circle) are different. It is a print sample of the case. As described above, in the embodiment, when the printing of the preceding line is completed and a line feed is made, the rotation angle of the platen becomes large in this line feed operation. Therefore, since the rotation speed of the platen is also high, the platen moves 0.1 mm due to inertia even after the step motor 6 is stopped. After that, the first printing process is performed. In the second printing process, the drive signal corresponding to 2 pulses is given to intermittently rotate the step motor 6 by (1/72) × (2/3) = 2/216 inches (about 0.235 mm). Since there is backlash in the gears 7 and 8 rows, there is a second dot at the position shifted in the paper feed direction by a value (about 0.135 mm) minus the value of the backlash t (0.1 mm). The pattern is printed. In this case, since the rotation is completed before the rotation speed of the platen becomes sufficiently high, backlash does not occur. Therefore, a print pattern in which the dots of the second time partially overlap the dots of the first time that are adjacent in the paper feed direction is formed. As a result, even if the print speed is set to a high speed, the print density It is possible to print high quality characters with high quality.

Reference numeral 38 is an auto-cut sheet feeder for automatically feeding cut-sheet paper, and reference numeral 39 is a speed changeover switch for changing over the printing speed to at least two types. It is possible to switch between 3 types: high-density printing speed (75 characters / second) when printing Chinese characters, standard speed (110 characters / second), and double speed (220 characters / second). The speed changeover switch 39 is provided on the panel switch 31 as the operation unit of the printer. The printing speed can be switched by a command from the host computer 50.

Reference numeral 40 is a gap adjustment drive circuit for adjusting the print gap by rotating the step motor in the gap adjustment mechanism in the forward and reverse directions. The panel switch 31 includes a key switch and one display unit (using a liquid crystal display device LCD), and the online switch enables online data exchange between the host computer 50 as a host device and the printer. This is a toggle switch that switches the status to the non-exchangeable offline status. A line feed switch for the "line feed" command that feeds one line of paper or a page feed command that feeds the paper vertically in page units. It is equipped with a page switch and a power switch to turn the printer power on and off. When the printer power switch is turned on, the printer goes online and receives print data from the host computer 50 to enable printing. ..

The integer values m and n may be appropriately set according to the magnitude of the backlash value of the gear train between the paper feed mechanism and the paper feed drive motor. It goes without saying that the present invention can also be applied to the case of printing with a character font of modified characters such as shaded white characters, italic characters and superposed characters, as in recent word processors.

[0027]

[Operation and effect of the device]

 As described above, according to the present invention, the paper feeding mechanism for transferring the printing paper in the printer and the driving mechanism such as the step motor are connected via the gear train, and this driving mechanism is connected to the serial dot printing head. Is configured to drive to feed the paper in units of the inter-dot distance of 3 or more divided into an integer m. After the normal printing process in this printer, the paper feed mechanism is moved from the m Paper is fed in units of n, which is a small number and is larger than m / 2, and at this time, the same pattern data as the dot pattern in the first normal printing or different pattern data is output to the print head. It prints.

As described above, when the paper is fed by a minute distance in the second printing step, even if there is a backlash in the gear train, it is possible to operate the drive mechanism by an extra amount corresponding to the backlash. It is possible to do dot printing in the gap between the upper and lower sides of normal printing in the second printing process, and it is possible to perform high quality printing with higher printing density than the normal printing pattern. ..

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a printer.

FIG. 2 is a functional block diagram of a control device.

FIG. 3 is a print sample when overprinting with the same dot pattern according to the present invention.

FIG. 4 is a print sample when overprinting with different dot patterns according to the present invention.

FIG. 5 is a diagram showing a distance between print wires of a serial dot print head.

FIG. 6A is an explanatory diagram of backlash during low-speed printing work. FIG. 9B is an explanatory diagram of backlash during high-speed printing work.

[Explanation of symbols]

 1 Platen 4 Print Head 5 Printing Paper 6 Step Motor 7 Drive Gear 8 Platen Gear 9 Second Gear 10 Third Gear 11 Fourth Gear 16 Central Processing Unit 30 Print Head Drive Circuit 35 Motor Drive Circuit 37 Paper Feed Motor Drive Circuit

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B41J 19/76 9212-2C 19/92 9212-2C

Claims (1)

[Scope of utility model registration request] 1. A paper feed mechanism for transferring a printing paper, and a paper feed mechanism for connecting the paper feed mechanism through a gear train, and for feeding paper in units of an interval m divided by an integer m of 3 or more. A printer device having a driving mechanism for driving is provided with control means for feeding paper in units of integer n smaller than m and larger than m / 2, and outputting arbitrary dot pattern data to a print head at this time. A printer device characterized by the above.