JPS591597B2 - dot matrix serial printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dot matrix type serial printer in which the width of characters to be printed can be varied.

A conventional dot matrix type serial printer generally has a configuration as shown in FIG.

That is, in FIG. 1, reference numeral 1 denotes a recording paper, which is fed upward by one printing line by a paper feed mechanism 2 every time printing of one printing line is completed. Reference numeral 3 denotes a print head, which is mounted on a fixed support frame (not shown) so as to be able to reciprocate along the print line, and the head surface 3a faces the line to be printed on the recording paper 1 via the ink ribbon 4. There is.

Reference numeral 5 denotes a nulling fence, which is made up of a large number of slits arranged regularly, and generates a so-called strobe signal at timing intervals corresponding to the slit pitch in relation to the movement of the print head 3.

This stroke signal is used as a timing signal to determine the printing position. Now, the conventional structure of the print head 3 is, for example, as described in Japanese Patent Application Laid-Open No. 47-U, and to explain it roughly, it consists of a plurality of print solenoids 6 and When the print wire is pushed out from the head surface 3a of the reprint head 3 by the print solenoid 6, the tip of the print wire hits the recording paper 1 via the ink ribbon 4 and creates a dot. Figure 2 shows such a conventional print head 3.
The front side of the head surface 3a and this print head 3
This shows dot matrix-like European characters printed by . As shown in the head surface 3a of FIG. 2, there are seven conventional print wires 7, which are lined up in a vertical line and held on the head surface 3a, thus forming dots for printing one character. Although the matrix can be formed in any number by moving the print head 3 in the horizontal or row direction,
The maximum number of dots in the vertical or column direction is limited to 7 dots. Assuming that the number of dots in the row direction is 5 and the number of dots in the column direction is 7, the dot matrix-like characters shown in Figure 2b are formed by printed dots within the range of the [5 x 7] matrix. However, if the movement pitch of the print head 3 is reduced to 1/2, the number of dots in the row direction will be 9, so
As shown in Figure 2c, the printed characters in this case are [9 x 7]
It is formed by printed dots within the matrix.
That is, the conventional method has a problem in that although the number of dots can be increased in the row direction, it cannot be increased in the column direction. This causes a problem in that when Japanese characters, especially Chinese characters, having complex patterns are printed in a dot matrix, the number of dots in the column direction is insufficient, making it difficult to decipher the printed characters. On the other hand, a new method for printing dot matrix characters that has recently been considered by the applicant of the present invention is as follows. This new method of printing characters in the form of a dot matrix will be explained below with reference to FIGS. 3 and 4. That is, 10 shown in FIG. 3A shows the head surface of a print head using the new method, and as shown in this figure, the print wires are adjacent to nine print wires 11a arranged in a line in the column direction and in parallel with these. and nine printed wires 11b similarly arranged on a line in the column direction, and one printed wire 11a,
The other print wire 11b row is 1/2 in the row direction.
They are arranged in a misaligned manner. According to the above-described arrangement of the print wires 11a and 11b, the number of dots in the column direction for one character can be up to 18, and moreover, the print wires 11a in one column...
Each printed wire 11b of the other row is placed in the pitch concavity of .
Since the dots are struck by the dots, the dot pitch of printed characters in a dot matrix is extremely small compared to the conventional method described above, and characters with complex patterns such as Chinese characters can be clearly printed. Figure 3b shows the characters printed by this new dot matrix type serial printer. Now, when printing Japanese characters, there are circumstances in which it is easier to read if the Japanese characters are printed out in a mix of kanji, kana characters, and even numbers, and the title characters are printed in Gossik font, and the characters are printed horizontally. A characteristic requirement of Japanese writing is that it should be able to be used not only in handwriting but also in vertical writing. Furthermore, one of the characteristics of Japanese text is that when kanji, kana characters, numbers, etc. are mixed, readability can be dramatically improved by adjusting the spacing between the printed characters appropriately according to the nature of the characters. , this requirement must also be met. This new method can fully satisfy the above-mentioned requirements specific to Japanese writing. In other words, the characters in the middle of the characters printed in the dot matrix pattern in Figure 3b, such as ``kan'' and ``ji'', are printed in the line direction. Kanji characters are printed within the range of 15 and 18 dots in the column direction and the number of dots in the column direction, respectively, that is, within the range of a [15×18] matrix. For convenience, this mode of Kanji characters is referred to as the K mode. Also, kana characters and numbers such as "pu", "l month", "1", "2", etc. shown in Figure 3b are smaller than K mode characters [7X
9] Printed within the range of the matrix, this is referred to as A mode.0 The character "mark" shown in Fig. 3b is a gothic font formed by thick lines and thin lines, and the thick line part is It is devised to form one line with two rows of dots, and when printing, especially for thick line parts, this is achieved by striking the same dot pattern again, shifted by one pitch. Such Gothic characters will be referred to as G mode. [
The old letters are printed vertically, and this is done by outputting dot pattern data, which is normally input serially in time corresponding to horizontal writing, in parallel when printing. Realized. Printing like this
This will be called a mode. Furthermore, “Yu” shown in Figure 3b
Even though the characters are kana characters, they are particularly printed in a mode in which they are positioned on the center line of the print line, and this will be referred to as the S mode. Figure 4 shows numerically the number of dots in the row and column directions of printed characters in K and A modes among the above modes, and also shows the space width between each printed character in terms of the number of dots. It is illustrated by numbers. As shown in Fig. 4, the space width between printed characters in K mode can be selected from either KP pitch or KE pitch, and the space width between printed characters in K mode and A mode and between printed characters in A mode can be selected. The width is AP pitch and AE
The system allows you to select one of the pitches. The pitches mentioned above are named for convenience in this system; KP and KE mean that the pitch widths in K mode are P pitch and E pitch, respectively;
, AE means that the pitch width in A mode is P pitch and E pitch, respectively, and P pitch is the space in which 5 characters in K mode and 10 characters in A mode are printed within an inch length. In terms of width, E-pitch means that it corresponds to the space width in which 6 characters in K mode and 12 characters in A mode are printed within a -inch length. Therefore, taking the case of KP pitch as an example, what is KP pitch?
This means that the pitch width is equal to the character spacing when five K mode characters are printed within an inch length.
As described above, this new type of dot matrix type serial printer can meet various requirements specific to printing Japanese characters, but it does not require the same control system as the conventional printing control device. When this is applied, in particular, the dot pitch in the row direction is mechanically determined by the structure of the timing fence, ie, the slit spacing for strobe signal generation, and cannot be varied.

If an attempt is made to vary it as shown in FIG. 2c, it will be extremely troublesome to have to replace timing fences with different slit pitches, and this also does not have the effect of changing the width of the characters to be printed. By the way, especially for Japanese characters, in addition to the various requirements mentioned above, it is also required to be able to vary the width of the characters to be printed so that the size of the printed characters can be substantially varied. Figure 2c
cannot be satisfied by the method shown in The present invention has been made in view of the above circumstances, and its purpose is to provide a structure in which the width of a character to be printed and the dot pitch in the printing line direction for forming one character can be varied by an electronic circuit. To provide a dot matrix type serial printer which can freely change the size of printed characters, that is, the width within the same character pitch.

An embodiment of the present invention will be described below.

However, since the means for varying the width of the space, which is a blank space between characters, is outside the scope of the present invention, a description thereof will be omitted. In addition, in the following explanation, character pitch refers to the distance between the centers of two characters, dot pitch refers to the distance between two dots in the line direction, and width of a printed character refers to the width of one printed character itself in the horizontal direction. It refers to the size. Now, FIG. 5 shows the entire system of this embodiment, which includes a character generator 20 that converts print data transferred in encoded form from the central processing unit CPU into dot pattern data, and the dot pattern data. pattern·
It consists of a print control device 21 for printing data.
The print control device 21 includes a buffer memory 22 that temporarily stores the dot pattern data sent from the character generator 20, writes the data into the buffer memory 22, and moves the accumulated data to the print head. a shift control circuit 23 for controlling readout in accordance with data readout from the buffer memory 22; a head drive circuit 24 for driving the print head for printing according to data read from the buffer memory 22; and a timing signal generation device to be described later. It consists of 25. FIG. 6 shows the specific connection relationship shown in FIG. 5. As shown in FIG. 1
18 shift registers S corresponding to 1b...
Each of them has a storage capacity of 1020 bits, which can print 68 characters in one print line when the number of dots in the line direction of one character is 15, that is, in K mode. The dot pattern data read from each of these shift registers SRl to SRl8 is used as a solenoid drive signal to drive solenoid drivers SDl to SDl, respectively.
Print solenoids SOLl to SOLl8 via 8
are beginning to receive a bounty. In addition, as shown in FIG. 3a, printed wires 11a... and 11b...
. . is divided into two rows on the left and right, so it goes without saying that the two rows of print wires are operated with a time difference for one minute of dot pattern data. FIG. 7 shows a portion of a timing signal generator 25, ie, a strobe signal generator, for determining the print position of a print head moving along a print line. In this Figure 7, 26
is a timing fence that constitutes a printing position indicating member,
This has a large number of positioning openings 27 (same as the number of characters to be printed in one printing line) arranged at regular intervals to determine the character pitch of printing as the print head moves. . On the other hand, a detection head for obtaining a positioning signal from such a timing fence 26 is provided in the print head, and as shown in FIG. A phototransistor 29 receives light passing through the positioning aperture 27. The timing fence 26 is fixedly provided between the print head movably mounted on the fixed support frame and the fixed support frame. FIG. 8 shows a strobe signal generating section that constitutes the timing signal generating device 25 together with the device shown in FIG.
In FIG. 8, 30 is an input terminal to which the positioning signal PSP generated from the phototransistor 29 is input.
Connect this to one input terminal of the AND circuit 3103
Reference numeral 2 denotes a variable frequency oscillator, which is composed of an oscillator 33 and a variable resistor 34 for varying its oscillation frequency, and sends its oscillation output signal 0SP to the other input terminal of the AND circuit 31 and one input of another AND circuit 35. 036, which is commonly supplied to the terminal, is a counter for determining the number of printing dots in the line direction within the character pitch. An output is generated until the voltage reaches the threshold, and this output is supplied to the other input terminal of the AND circuit 35 as a gate signal. 37 is a count value setting device that sets the count value of the counter 36 to the same value as the number of dots in the line direction of the printed character according to various printing modes of the data to be printed;
has a function of clearing the count to zero when the count value set by the count value setter 37 is reached.

The output of the AND circuit 35 is supplied via the shift control circuit 23 to each of the shift registers SRl to SRl8 as a shift pulse for reading. Next, the operation of the above configuration will be explained.

First, the print data sent out from the central processing unit CPU in a coded state is sent to the character generator 20.
The dot pattern data D1 output from the character generator 20 while being decoded is input to each shift register SRl of the buffer memory 22 as is.
SRl8 to SRl8 are serially and continuously supplied. At this time, the shifts for writing in each of the shift registers SRl to SRl8 are executed by receiving a clock pulse CP shown in FIG. 6 from the central processing unit CPU via the shift control circuit 23. In this way, the decoded print data, that is, the dot pattern data D1, for one print line is temporarily stored in the shift registers SRl to SRl8. Next, the printing operation will be described.
First, when the start switch provided on the printer body is operated, the print head starts moving along the print line by a feed motor (not shown), and as it moves, the print head moves as shown in FIG. 3b. The mode characters are printed in a dot pattern. To explain this in detail, when the print head starts moving, the light projector 28 provided at the detection head of the print head starts irradiating the timing fence 26 in a scanning state. As shown in FIG. 9b, a pulsed positioning signal P is generated as shown in FIG.
Generates SP. This positioning signal PSP determines the character pitch for printing as the print head moves, and is supplied to one input terminal of the AND circuit 31 via the input terminal 30 in FIG. On the other hand, the oscillator 33 is constantly oscillating and supplies an oscillation output signal 0SP as shown in FIG. 9c to one input terminal of each of the AND circuits 31 and 35. The oscillation frequency at this time is adjusted by the variable resistor 34, and in this embodiment is set to f1, for example, so that seven pulses can be uniformly distributed within the mark pulse width of the positioning signal PSP. The oscillation output signal 0SP passes through the AND circuit 31 and is supplied as a counting input to the counter 36 only while the mark portion pulse of the positioning signal PSP is present. This counter 36
is set in advance to the maximum count value 7 by the count value setter 37, so it counts from the time when the first oscillation output signal 0SP is input until the count reaches 7, and outputs continuously during that time. is supplied to the AND circuit 35 as a gate signal. Therefore, since the oscillation output signal 0SP passes through the AND circuit 35 only during this period, its output becomes a signal consisting of a group of seven pulses as shown in FIG. This occurs intermittently in multiple groups, and this is the strobe signal STVP.
In other words, this strobe signal STVP is not generated in the non-opening portion 27a of the timing sensor 26, and therefore, as shown in FIG.
(corresponding to A mode) occurs, and the space position (non-opening part 27
The minimum space width is determined by matching the time length of the width of a. )
This results in a signal pattern that does not occur at all. As shown in FIG.
The dot pattern data D1, which is supplied as a shift pulse for reading to the dot pattern data D1 and stored in each of the shift registers SRl to SRl8, is read out in parallel, 1 bit at a time, each time one strobe signal STVP is received. , which is supplied as a solenoid drive signal S1 to print solenoids SOLl to SOLl8 via solenoid drivers SDl to SDl8, and dots are struck on the recording paper one column at a time by a print wire in the row direction for each reading cycle of dot pattern data. Therefore, one character is printed by one group of strobe signals STVP, and the distance between each group is the space width between printed characters. In this case, the timing of striking each dot in the row direction is synchronized with each strobe signal STVP, so if the oscillation frequency of the oscillator 33 is varied by the variable resistor 34, the frequency of the strobe signal STVP will change. The pitch of each dot in the row direction is also varied. However, due to the variable oscillation frequency, the positioning signal P
Even if the number of pulses of the oscillation output signal 0SP existing within the time width of one mark portion of SP changes, the maximum count value of the counter 36 is set to 7 (in the case of this embodiment) by the count value setter 37. Therefore, the number of strobe signals STVP in one group is fixed at seven and does not change. Therefore, as the oscillation frequency of these seven strobe signals STVP becomes higher than f1, the distribution becomes denser than that shown in FIG. The distribution is as follows. In this way, even if the oscillation frequency is varied, characters in a dot pattern can be printed without any inconvenience with the number of dots in the line direction according to the printing mode. By varying the oscillation frequency of the variable frequency oscillator 32 in this way, the dot pitch within the character pitch can be varied, so the higher the oscillation frequency, the narrower the width of the printed character, and the lower the oscillation frequency, the wider the width of the printed character. It is variable so that The fact that the width of the printed characters can be varied in this way means that the size of the printed characters can be substantially varied. This is convenient for printing. Naturally, by varying the width of the printed characters, the width of the space between them can also be determined in various ways. In the present invention, as described above, the printing is performed in synchronization with the timing signal from the timing signal generator for determining the printing position of the print head moving along the printing line and in accordance with the dot pattern data of the characters to be printed. In a serial printer that prints characters in a dot matrix by driving a print head, the timing signal generating device includes a timing fence for determining character pitch as the print head moves, and a timing fence for determining character pitch within the character pitch. a variable frequency oscillator for determining dot pitch, the output signal of the oscillator being used as a timing signal to the print head;
By changing the width of the characters to be printed by changing the oscillation frequency, the size of the printed characters, that is, the width, can be changed within the same character pitch, and it is possible to print not only European characters but also Japanese characters in particular. It is possible to provide a dot matrix type serial printer that is convenient when

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a typical dot matrix type serial printer, Fig. 2 is a view showing the head surface of a conventional print head and the characters printed by it, and Fig. 3 is a diagram showing the print head of a conventional print head. A diagram showing the head surface of the print head and characters printed thereby in a dot matrix type serial printer of a new method to which the invention is applied; FIG. 4 shows the types of printing modes and space widths in the method shown in FIG. 5 is a block diagram showing the configuration of the printing control device according to the present invention. FIG. 6 is a configuration explanatory diagram showing the connection relationship between the buffer memory and head drive circuit of the embodiment of the present invention. Figure 7 I
Fig. 8 is a circuit diagram showing the timing signal generation section of the timing signal generation device, and Fig. 9 shows the timing fence and various components. FIG. 3 is a diagram showing the relationship with signals. In the figure, 10 is a head surface, 11a and 11b are print wires, 20 is a character generator, 21 is a print control device, 22 is a buffer memory], 23 is a shift control circuit, and 2
4 is a head drive circuit, 25 is a timing signal generator, 26 is a timing fence, 27 is a positioning opening,
32 is a variable frequency oscillator, 36 is a counter, 37 is a count value setter, SRl to SRl8 are shift registers, SD
l to SDl8 are solenoid drivers, SOLl to SOL
OLl8 is a print solenoid.

Claims (1)

[Claims] 1. Driving the print head for printing in synchronization with a timing signal from a timing signal generator and in accordance with dot pattern data of the character to be printed, in order to determine the print position of the print head moving along the print line; In a serial printer that prints characters in a dot matrix, the timing signal generating device includes a timing fence for determining the character pitch as the print head moves, and a timing fence for determining the dot pitch within the character pitch. A dot matrix type serial printer, comprising: a frequency oscillator; an output signal from the oscillator is used as a timing signal to the print head; and by changing the oscillation frequency, the width of characters to be printed is changed.