JPH0524263A - Drive controller for wire dot-type printing head - Google Patents

Abstract

(57) [Abstract] [Purpose] When printing at 1,5x speed, the total number of printed dots must be about 2/3, but for the 2 horizontal dots, that part is 1. It is 5 times thicker. The present invention prevents this. [Structure] At 1.5x speed, first, the dot data is set to 2
The double unfolding device 80 doubles in the lateral direction. After that, when the printing is performed in the previous time and the time before the previous time, the comparator 84 controls so that the dot is not formed. At this time, if the original print data in which two dots are lined up in the horizontal direction is printed at 1,5 times speed, the number of dots to be printed becomes two, and the interval is 1.5 times that of the regular one (1 times speed). Becomes Therefore, when the normal continuous dots are formed, the print timing is delayed so as to be shifted backward for the second and subsequent dots. However, in the present apparatus, when the history determination unit 100 determines that the continuous dots are the final dots, Don't put this delay on the last dot.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a print head, and more particularly to a drive control device for a print head, in which the print wire is projected while moving relative to the print medium to form dots on the print medium. The present invention relates to improvement of drive control of a wire dot type print head that forms a dot and prints a character by the set of dots.

[0002]

2. Description of the Related Art Some printers provided with a wire dot type print head can move the print head and a print medium relative to each other at 1 × speed and 1.5 × speed. Conventionally, when printing is performed at a speed of 1.5 times in this type of printer, the line intersecting the printing direction, that is, the relative movement direction between the print head and the printing medium becomes thick for the following reasons, and the printing quality deteriorates. There was a problem.

When a plurality of dots are continuously formed in the printing direction by a wire dot type print head, the process shown in FIG.
As shown in Fig. 4, at the time of first dot formation, there is a constant delay time from when the wire drive device issues the first wire ejection command (after the energization is started) until when the print wire actually starts ejection. While there exists
When the second and subsequent dots are formed in response to the second and subsequent wire ejection commands, the print wire bounces and projects at the lead-in end, so there is no delay time.
Therefore, when the wire protrusion command is always issued in a constant cycle, the dot interval between the first dot and the second dot is narrowed, and the thickness of the line intersecting the printing direction is reduced accordingly.

In order to avoid this, in the conventional wire dot printer, as shown in FIG. 15, the wire protrusion command for forming the second and subsequent dots has the same time as the delay time generated when the first dot is formed. It is designed to be delayed only. By doing so, the start of the wire protrusion is delayed by the same time when all the dots are formed, the dot interval becomes constant, and it is possible to prevent the line intersecting the printing direction from becoming thin.

On the other hand, the relative moving speed with respect to the print medium is 1.5.
When the number is double, the dots forming the character are thinned out. Since the 1 × speed is usually determined by the maximum operable cycle of the print wire, it is not possible to increase the operating cycle of the print wire even if the relative movement speed to the print medium is increased by 1.5 times. Therefore, in the case of 1.5 times speed, dot thinning is performed,
The print wire operating cycle is set to the maximum operable cycle.

In this thinning-out, if a line intersecting the printing direction is formed by two dots arranged in the printing direction, simply thinning out one dot will make each line one dot. Being formed, it becomes too thin.
Therefore, the number of dots in the printing direction is kept to be two, and the dot interval is increased by 1.5 times so that the operation of the wire is in time.

In the conventional print head, even in such a case, the wire protrusion command for forming the second and subsequent dots is delayed by the delay time as in the case of the 1 × speed. As described above, the line spacing becomes slightly thicker due to the dot spacing being 1.5 times, but the line was further thickened due to the delay of the wire protrusion command, and the problem of print quality deterioration occurred. I was doing it.

[0008]

In view of the above circumstances, the present invention is capable of moving the print medium relative to the print medium at 1 × speed and 1.5 × speed, and during the relative movement, the print wire is driven by the wire driving device. Is operated to form dots on the print medium, and a character is printed by the set of dots. In a wire dot printer, the thickness of the line that intersects the printing direction is reduced even when printing at 1.5 times speed. It is an object of the present invention to obtain good print quality without being excessively large.

[0009]

The gist of the present invention is to provide a drive control device for a wire dot type print head,
In the case where the wire moving command for forming the final dot of the plurality of dots continuously arranged in the relative movement direction of the print medium and the print head to the wire driving device is the relative moving speed is 1 × speed. In the above, there is provided a wire protrusion command generating means which emits with a delay of a predetermined delay time and emits without delay when the speed is 1.5 times.

[0010]

As described above, when the wire protrusion command for forming the final dot is issued without delay during printing at 1.5 times speed, lines intersecting the printing direction are arranged in the printing direction. When the dots are formed by individual dots, the wire protrusion command for forming the second dot is issued without delay.

When two dots which are continuously arranged in the printing direction are formed at 1.5 times speed, the pitch between dots is set to 1.5 times as described above. In the drive control device according to the second aspect, the wire protrusion command for forming the second dot is issued without delay, the dot interval is reduced by that amount, and eventually the dot is formed by two dots each. Excessive line thickness is avoided. The increase in the dot distance due to the increase in the movement distance of the print head during the 1-dot forming period during the printing at 1.5 times speed is reduced by omitting the delay of the wire protrusion command.

The problem that the thickness of the line intersecting the printing direction becomes excessive at the time of printing at 1.5 times speed is that the line intersecting the printing direction is formed by two dots arranged in the printing direction. Especially important to. When printing Chinese characters, a line is often formed by two dots even if the number of printing points is considerably large, and the same happens when the number of printing points is reduced when printing alphabets, numbers, and kana. .. The present invention has been made mainly for the purpose of solving the problem when a line is formed by two dots each. However, when a line intersecting the printing direction is formed by four dots, the number of dots is three, and the dot pitch is 1.5.
It also occurs when the number is doubled, and the present invention can be applied to this case.

However, when a line intersecting the printing direction is formed by three dots arranged in the printing direction and one central dot is thinned out at the time of printing at 1.5 times speed, the line Since the thickness becomes thin, it is desirable to delay the wire protrusion command for forming the second dot as usual. Therefore, the wire protrusion command for forming the final dot is issued only when the number of dots arranged in the printing direction is two or only when the line thickness becomes excessive due to thinning at the time of printing at 1.5 times speed. It is desirable not to be delayed.

[0014]

As is apparent from the above description, according to the present invention, it is possible to obtain the effect that the printing quality at the time of 1.5x speed printing is improved as compared with the conventional case. Moreover, since the object can be achieved by a simple means of omitting the delay of the wire protrusion command at the time of forming the final dot, the quality improvement effect can be obtained with almost no increase in cost.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 2 shows the main part of the wire dot printer. Reference numeral 10 is a platen, and the side frame 1
2 and 14 are rotatably supported. The platen 10 supports a printing paper 16 as a printing medium and also functions as a component of a paper feeding device that feeds the printing paper 16 in the vertical direction. Carriage guide 1 parallel to platen 10
8 and 20 are provided to support the carriage 22 so as to be movable laterally along the platen 10. The carriage 22 is laterally moved by a carriage driving device 32 including a carriage driving motor 24, timing pulleys 26 and 28, a timing belt 30 and the like.

A print head 40 is mounted on the carriage 22.
Is mounted and moves along the platen 10 as the carriage 22 moves. The print head 40 includes 24 print wires (hereinafter, abbreviated as wires) 42, and the tips of these wires 42 are arranged in a rhombus, as shown in FIG. The numbers in the figure indicate the number of the wire 42, such as 1 and 23, 3 and 21 and 2
The wires 42 are arranged at the same position in the moving direction of the print head 40. By selectively projecting these wires 42 by a wire drive device 46 mainly composed of the laminated piezoelectric element 44, dots are formed at arbitrary positions of dot formation positions planned in a 24 × 24 matrix, Characters such as kanji, kana, alphabets, numbers, and symbols are printed by the set of these dots.

The control circuit of this printer is shown in FIG. The control circuit includes a main central processing unit (abbreviated as MCPU) 50 and a sub central processing unit (SCPU) 52, which are connected to two buffers 56 and 58 and a gate array 60 via a gate array 54. There is. The gate array 54 includes an I / O controller 62, a buffer controller 64, an internal register 66, a decimator 6
8 and rhombus converter 70.

The gate array 54 occupies the two buffers 56 and 58 during printing, but the buffer controller 64 receives the print data from one of the two buffers in response to the print timing pulse PCK from the SCPU 52 without the assistance of the MCPU 50. The data is read and developed into pin data corresponding to each of the 24 wires 42. Therefore, MCPU
In parallel with this, 50 can store print data in the other of the buffers 56 and 58.

When storing the print data, the thinning unit 68 thins the print data if necessary. If the print speed is specified as 1x speed, MCPU50
The print data supplied from the printer is stored in the buffer 56 or 58 as it is. However, when the 1.5 times speed is designated, the interval of dots to be continuously printed by the same wire 42 is 1 The print data is thinned out and stored in the buffer 56 or 58 so that it becomes 5 times larger. For example, the print data illustrated in FIG. 5 is changed to the thinning data illustrated in FIG. In the figure, circles represent data for instructing dot formation. The dots that are continuously formed by the same wire 42 are thinned so that the interval between them becomes 1.5 times. If the dot interval is 1.5 times as described above, the print head 40 is 1. Even when the wire 42 is moved at the 5 × speed, if the printing operation is performed at the same cycle as in the 1 × speed, a plurality of dots can be formed continuously in the printing direction.

The pin data developed by the buffer controller 64 is diamond-shifted by the diamond converter 70. 24 of the printhead 40 as described above
The wires 42 of the book are arranged in a rhombus, and the pin data for one column are not executed at the same time.
When the print data for one column is all data for instructing dot formation, the two wires 42 are operated while being shifted by a minute time, so that the wires 4
The data of one column (24 bits) is shifted so that the dots formed by 2 are consequently positioned on a vertical straight line.

The rhombus-shifted print data (diamond shift data) is supplied to the gate array 60, and drive pulses for the print head 40 are generated as described later. The drive pulse of each laminated piezoelectric element 44 that drives each wire 42 is created based on the print data.

Decimator 68, buffer controller 64
Details of the gate array 60 are shown in FIGS. 7, 8 and 9, respectively.

First, the decimator 68 will be described. 1
If dots are formed at 1/180 inch intervals at double speed, in order to make the operating period of the wire 42 the same as at 1 × speed when the print head 40 is moved at 1.5 times speed. , Dots must be formed at intervals of 1/120 inch. Therefore, the thinning-out device 68 performs a process of changing the print data before thinning, which is created so that dots are formed at 1/180 inch intervals, into thinning data in which dots are formed at 1/120 inch intervals. Be seen. As shown in FIG.
Once the dots have been changed so that they are formed at 1/360 inch intervals, they are removed by 1/120
This is the thinning data in which dots are formed at inch intervals.

To this end, the decimator 68 includes a double expander 80, a 6-bit shift register 82, and a 6-bit shift register 82, as shown in FIG.
It comprises a comparator 84, a data latch 86, and the like.
Eight systems are provided for these circuits, and data of 1 byte (eight pixels) is processed in parallel. Double expander 80
Print data that is created so that dots are formed at 1/180 inch intervals by increasing each bit data by 2 bits. Printing before thinning in which dots are formed at 1/360 inch intervals. It is a circuit that changes to data. The data latch 86 is a circuit that latches the output signal of the comparator 84 by using the rising edge of the write signal WR as a latch trigger, and the 6-bit shift register 82 shifts the falling edge of the write signal WR one bit at a time as a shift clock. Is a circuit for storing the output signal of

Since the print head 40 is capable of printing a character composed of 24 dots per column,
Data of 3 bytes is required for one column, and data of 6 bytes before is required for thinning out two dots. The data latch 86 and the 6-bit shift register 82 are provided to create this data, and the comparator 84 compares the output signal of the double expander 80 with the output signal of the 6-bit shift register 82. The data is created after thinning.

In the apparatus of this embodiment, since the data of 24 pins is processed by 8 pins at a time, the fact that the 3rd bit or the 6th bit of the 6-bit shift register 82 is the data for instructing dot formation is , Means that a dot was formed last time or two times before by the target pin. Therefore, in the comparator 84, 6
The logical sum (OR) of the third bit and the sixth bit of the bit shift register 82 is taken, and the logical negation (NO) of the logical sum.
The logical product (AND) of T) and the output of the double expander 80 is taken. As a result, when a dot is formed at a certain time point, the value of the logical product becomes 0 even if the output of the double expansion unit 80 instructs dot formation at the next and next printing timings. The data after thinning out becomes data for instructing non-formation of dots. As a result, if the double expanded data is the one illustrated in FIG.
The data after thinning shown in 2 will be created.

Next, the buffer controller 64 will be described. As shown in FIG. 8, the buffer controller 64 includes a 6-byte load clock generator 90, an address counter 92 and a pin data expander 94. 6
Byte load clock generator 90 is from SCPU 52 to 1
It is a circuit that supplies the read signal RD to the buffer 56 or 58 and supplies the six clock pulses to the address counter 92 sequentially each time the print timing pulse PCK is supplied. The address counter 92 is loaded with a print data read address preset by the MCPU 50 in response to the print timing pulse PCK. The address counter 92 is also supplied with a signal FR indicating whether the printing direction is the forward direction or the reverse direction, and the address counter 92 is supplied every time one clock pulse is supplied from the 6-byte load clock generator 90. The address of the buffer 56 or 58 specified by is changed according to the printing direction, and the data for the leading pin and the trailing pin for a total of 6 bytes are read from the buffer 56 or 58 by 3 bytes in total, and the pin data expander is read. Sent to 94.

The 6-byte data is arranged in two columns in the pin data expansion unit 94 in consideration of the printing direction. The pin data expander 94 is also supplied with the signal FR indicating the printing direction. When this signal indicates the normal direction, data of 3 bytes each is arranged in one column in the order of reading and is reversed. In the case of the direction, the previously read 3-byte data and the subsequently read 3-byte data are reversed and arranged in two columns.

The print data thus developed into pin data is rhombus converted by the rhombus converter 70 and sent to the gate array 60. The gate array 60 includes a history determination unit 100, a history control unit 102, and a simultaneous operation control unit 10 shown in FIG.
4, a processing circuit including an ON time width storage unit 106, a delay control unit 108, a print pulse generation unit 110, and an output control unit 112 is provided for each of the 24 wires 42.

The history judgment unit 100 stores the current print data and the print data before and after the current print data, and generates the print pulse of the previously printed data HI, the current data PD and the data PEN to be printed next. The previously printed data HI is supplied to the unit 110 to the history control unit 102. The history control unit 102 has a previous history, that is, the previously printed data HI is data for instructing dot formation, or there is no previous history, that is, the previously printed data is data for instructing non-dot formation. Depending on whether or not the previous time is ON time Ta1 with no history or previous time without history ON2 Ta2, ON time value B1-
5 and the latch signal G (1-24) are supplied to the ON time width storage unit 106. Further, the ON time value B1-5 and the latch signal G (11-14) are supplied to the simultaneous operation control unit 104.

Simultaneous operation control section 104 includes (1) 11, 1
When only the 3rd wire is driven at the same time and the 11th and 13th wires were not driven last time, (2) 12, 14
It is determined that only the # 2 wire is driven at the same time, and neither the 12th wire nor the 14th wire is driven, and (1), (2)
In either case, the ON time Ta3 for simultaneous operation is selected to select the ON time values BT11 and BT12 and the latch signal G.
T (11-14) and T (11-14) are supplied to the ON-time width storage unit 106, and if none of them applies, the history control unit 102 is selected.

The ON time width storage unit 106 stores the ON time width data selected and supplied as described above for each of the 24 wires.

The delay control unit 108 is provided in order to delay the print timing signal by the time corresponding to the position of each wire because the wires 42 for forming the dots of one column are arranged in a rhombus as described above. The print timing pulse corrected for each wire is supplied to the print pulse generator 110. The delay control unit 108 uses the print timing pulse P
Every time CL is input, the delay timer is reset to start counting. The basic clock of the built-in timer is selected according to the moving speed of the carriage 22, and the delay control unit 108 controls the count value DRT of the built-in timer.
M1-3 is compared with the values set by 12 addresses, and when both match, the TDL signal is turned on, and when they do not match, the TDL signal is turned off. Two wires 42 are provided at the same position in the moving direction of the carriage 22, such as No. 1 and No. 23, and No. 3 and No. 21, and the delay time is made common to these two wires 42. To get
It is only necessary to set 12 types of delay times.

The print pulse generator 110 is a circuit for generating a print pulse based on the various signals created as described above, and as shown in FIG.
Is equipped with. The timer comparator 120 includes the timers 122 and 1
24 is built in, and is selected by the history control unit 102 or the simultaneous operation control unit 104 based on the print data PEN to be printed next, which is supplied from the history determination unit 100, and the print data HI printed last time. ON time Ta
1, 2, 3 and a preset delay time T
b, the combination of the brake pulse start time Tc and the brake pulse end time Td is determined, and when the current print data PD is ON, the print pulse HA is generated in synchronization with the signal TDL supplied from the delay control unit 108.

The case where the printing speed is 1 × speed is shown in FIG. When the previously printed print data HI is data for instructing non-formation of dots, that is, when the print pulse is the first shot, the delay time Tb is not given and the energization time Ta2 is energized. On the other hand, when the previously printed print data HI is data for instructing dot formation, that is, when the energization is after the second shot, the delay time Tb is given and the energization for the energization time Ta1 is performed. Be seen. When the print data PEN to be printed next is data instructing non-formation of dots, that is, when the energization is final,
After energization for the energization time Ta1, a brake pulse is generated from the time when the brake pulse start time Tc elapses to the time when the brake pulse end time Td elapses without giving a delay time.

The case where the printing speed is 1.5 times speed is shown in FIG. Also in this case, the first dot and the second and subsequent dots among the dots that are continuously formed are formed at the energization time Ta2 without the delay time and the energization time Ta1 with the delay time Tb, respectively. However, it is 1 in that the final dot is formed in the energization time Ta1 without delay time.
Different from the double speed case.

As described above, in the case of the 1.5 × speed, the final dot is formed in the energizing time Ta1 without the delay time, so that the print head 4 is supplied during the delay time Tb.
The dot spacing becomes narrower by the distance that 0 moves. In the case of 1.5 times speed, the distance that the print head 40 moves during the printing cycle is increased by 50% as compared with the case of 1 times speed. Since the increase in the moving distance of the print head 40 between them is reduced, the width of the vertical line formed by two dots becomes close to that when the width of the vertical line is 1 × speed.

For example, if the printer is capable of printing 150 characters per second with a character allocated to a total of 27 columns, each of which has 24 character columns and 3 space columns, the dot pitch is 1/18.
At 1 × speed, which is 0 inch, the print head 40 moves 150 × 27 × 25.4 / 180 = 572 millimeters per second. In addition, the delay time from the start of energization at the time of the first dot formation until the wire actually begins to project is 60
If it is μs, the delay time Tb given at the time of forming the second and subsequent dots is 60 μs.

When printing is performed at 1.5 times speed, the dot pitch is 1/120 inch, that is, 2
5.4 / 120 mm, (25.4 / 1
20)-(25.4 / 180) = 0.071 mm longer, but 1.5 × 5 because the delay time of 60 μs is omitted when the final dot is formed.
72 × 60 × 10 ⁻⁶ = 0.051 mm shorter, and in the end, the thickness of the vertical line formed by two consecutive dots only needs to be 0.071−0.051 = 0.02 mm thicker. Become. When the delay time of 60 μs is given as usual, originally, 25.4 / 180 =
The vertical line, which should be 0.141 millimeters, becomes thicker by 0.071 millimeters and increases by almost 50%, whereas in the apparatus of this embodiment, it becomes only 0.02 millimeters thicker by 14%. It's done.

In this embodiment, when three or more dots are continuously formed at 1.5 times speed, the delay time Tb is omitted only when the final dot is formed. However, the provision of the delay time Tb may be omitted when forming all the second and subsequent dots. In the former, the interval between the last dot and the dot before it becomes shorter by the delay time, whereas in the latter, the interval between the first dot and the second dot becomes shorter by the delay time only. This is because there is no apparent difference in the print results.

Further, in the present embodiment, the determination as to whether or not to give the delay time at the time of forming the final dot at 1.5 times speed is made by the digital circuit, but it may be made by software. It is possible. For example, the CPU pre-reads the data at the next print timing to determine whether or not to give the delay time.

Further, in this embodiment, the wire is driven by the wire driving device 46 mainly composed of the laminated piezoelectric element 44. However, in the print head equipped with the wire driving device mainly composed of the solenoid. The present invention can also be applied to a drive control device. In addition, although not exemplarily illustrated, it goes without saying that the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a graph showing a comparison of energization states of a wire driving device when 1 × speed printing and 1.5 × speed printing are performed in a print head drive control device according to an embodiment of the present invention.

FIG. 2 is a plan view schematically showing the periphery of a print head of a printer including the print head drive control device of the above embodiment.

FIG. 3 is a view conceptually showing the arrangement of the tip portions of print wires in the print head.

FIG. 4 is a block diagram of the print head drive controller.

FIG. 5 is a diagram showing an example of a character printed at 1 × speed by the print head drive control device.

FIG. 6 is a diagram showing a state in which dots of the character are thinned out for printing at the 1.5 × speed.

FIG. 7 is a block diagram showing a configuration of a decimator of the print head drive controller.

FIG. 8 is a block diagram showing a configuration of a buffer controller of the print head drive control device.

FIG. 9 is a block diagram showing a configuration of a gate array of the print head drive controller.

FIG. 10 is a diagram for explaining thinning-out by the thinning-out device in FIG. 7;

FIG. 11 is a diagram for explaining thinning-out by the thinning-out device in FIG. 7;

FIG. 12 is a diagram for explaining thinning-out by the thinning-out device in FIG. 7;

FIG. 13 is a diagram for explaining a print pulse generator of the gate array of FIG.

FIG. 14 is a diagram for explaining a problem in the case where a delay time is not given during 1.5 × speed printing by the conventional print head drive control device.

FIG. 15 is a diagram for explaining a case where a delay time is given during 1.5 × speed printing by a conventional print head drive control device.

[Explanation of symbols]

 22 Carriage 40 Print Head 42 Print Wire 44 Laminated Piezoelectric Element 45 Wire Drive Device 100 History Judgment Section 102 History Control Section 106 ON Time Width Storage Section 110 Print Pulse Generation Section

Claims (1)

Claim: What is claimed is: 1. A printing wire is movable relative to a printing medium at 1x speed and 1.5x speed, and a print wire is operated by a wire driving device during the relative movement to form dots. Then, in the drive control device of the wire dot type print head for printing a character by the set of the dots, to the wire drive device for forming the final dot of the plurality of dots lined up continuously in the relative movement direction. The wire protrusion command of (1) is issued with a delay of a predetermined delay time when the relative movement speed is 1 × speed, and is output without delay when the relative movement speed is 1.5 × speed. A drive control device for a print head, characterized in that: