JPS6353950B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a control device for a dot printing device in which a plurality of printing hammers having dot elements are arranged horizontally and the printing hammers are reciprocated in the horizontal direction to print. Such a dot printing device reciprocates a group of printing hammers across a printing paper, and in the process of this reciprocating movement, drives the printing hammers to print.
That is, one line of dots is printed in the horizontal direction in one direction of the reciprocating motion, and then the printing paper is advanced to the next vertical dot printing position, and then one line of dots is printed in one direction of the reciprocating motion. This operation is repeated a predetermined number of times to form and print characters consisting of a predetermined number of dots in a matrix in the horizontal and vertical directions. When printing alpha characters, numbers, symbols, katakana, etc., a print data code is transferred from a host device such as a CPU, and this print data is temporarily stored in a print data buffer (hereinafter referred to as PLB).
When the transfer of print data for one line is completed, a data transfer end command is transferred, and the printing device starts printing. To print the specified characters in each digit, use the character generator (hereinafter referred to as
CG), the required dot pattern information is read out by comparing the horizontal and vertical positions.
This is done by driving the printing hammer according to the information. There are various numbers of dots that make up a character, but a matrix configuration of 5 dots in the horizontal direction and 7 dots in the vertical direction will be explained. An example of printing with this character structure is shown in FIG. 1, and dot pattern information in the CG for numbers 1 and 2 is shown in Tables 1 and 2, respectively. In this character structure, the dot matrix is horizontal 5,
It consists of 35 vertical 7 dots.

【table】

[Table] When printing the above alphanumeric characters, numbers, katakana, etc., it is not necessary to print all 35 dots; on average, about 40% of the dots, and at most about 60%, can be used to form characters. Therefore, it is sufficient that the performance of the printing hammer, its driving circuit, etc. can withstand continuous operation of about 60% of 35 dots. On the other hand, dot printing devices can not only print characters using dots as described above, but also print dots at any position on printing paper, so they can be used to draw figures, large characters (from the 35-dot characters mentioned above), and print dots at any position on printing paper. (also large characters) can be printed. When printing these figures and large characters, a dot print pattern of one dot line in the horizontal direction is transferred from the host device, and this method will be explained below. It was mentioned earlier that characters such as alphabets, numbers, and katakana are composed of five dots in the horizontal direction, but in order to maintain space between each character, an interval of one dot is provided. Therefore, the number of horizontal dots in one digit is six. The code transferred from the host device is normally 7 or 8 bits. By associating 6 bits of these bits with 6 dots in the horizontal direction of each digit, it becomes possible to print dots at arbitrary dot positions as follows. A case in which a part of the figure shown in FIG. 2 is drawn will be described. Print dots at the positions indicated by circles in the 1st, 2nd, and 3rd digits of vertical position 1. PLB consists of 8 bits for each digit, of which 6 bits, bits 1 to 6 are used (alphabet,
All 8 bits are used for numbers and katakana codes). Bit 1 corresponds to horizontal position 1 of each digit, bit 2 corresponds to horizontal position 2, and so on, and bit 6 corresponds to horizontal position 6. Bits 7 and 8 are ignored. In addition, before the PLB starts printing at vertical positions 1 to 4, the print data at each vertical position is transferred.
- Shown in Table 6. Note that the position where dots are printed is set to a logical value of 1, and the position where no dots are printed is set to a logical value of 0. (X indicates that the logical value can be either 1 or 0)

【table】

【table】

【table】

[Table] When transferring such a dot print pattern of 1 dot line in the horizontal direction, and before starting printing with the 1 dot line transfer end command, check that the transferred data is a dot print pattern rather than a code indicating a character. The CPU 100 transfers a command indicating that the code currently being transferred is a dot printing pattern using another signal line, or causes the printing device to recognize it using a switch or the like. When the printing device recognizes that the printing pattern is a dot print pattern, without reading the dot pattern information from the CG, it collates the horizontal position from the dot print pattern on the PLB, reads the necessary bit information, and drives the printing hammer. to print figures, large characters, etc. In this case, since it is possible to print at any dot position, at most 60% of the 35 dots can be printed, as in the case of letters.
It cannot be said that only one dot is printed, and furthermore, the number of dots increases by one dot for each digit in the horizontal direction, so strict performance is required of the printing hammer and its drive circuit. Configuring the printing hammer, its driving circuit, etc. to withstand this worst case inevitably increases the price of the printing device. In addition, the cooling device as a countermeasure against the heat generation of the coil of the printing hammer has also become larger, resulting in various disadvantages such as an increase in the weight of the printing device and an increase in power consumption when a blower or the like is used. An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to make it possible to manufacture a printing device at low cost without reducing the actual printing speed, and to reduce weight and power consumption. The present invention monitors the code transferred from the host device, adds up the dot printing information assigned to each printing hammer, and if a printing hammer prints a number of dots larger than a predetermined number, that one dot is The printing of a line is completed in one round trip, and the performance of the printing hammer, its drive circuit, etc. is not set more strictly than necessary. Before explaining the control device of the present invention, a case will be explained in which characters such as alphabets, numbers, symbols, and katakana are explained. When the printing device becomes able to receive print data from the host device 1, the data transfer start signal i becomes logical 1, and the flip-flop 12 is reset. This signal i is also sent to the host device 1, and the print data a is transferred from the host device 1. Print data a consists of 8 bits and is a code corresponding to a character. This print data a is written to the PLB 2 by a synchronization signal (not shown) from the host device 1. When the host device finishes transferring one line of print data a in this manner, the host device 1 sets a one-line data transfer end signal (not shown) to a logical value of 1 to notify the printer of the end of data transfer. When the printing device receives this signal, it ends the data reception cycle and shifts to the printing cycle. Since the print data a transferred at this time is a code specifying a character, the plot mode signal h has a logic value of 0.
Therefore, the AND gate 21 keeps its gate closed, and since the output of the inverter 19 has a logic value of 1, the AND gate 20 opens its gate if the output signal o of the data selector 7 has a logic value of 1, and outputs the hammer drive signal. When q becomes a logical value 1, the printing hammer is driven to print a dot on the paper. Next, a method for printing dots forming each character at predetermined printing positions will be explained. Print data a to be printed on a certain digit is stored in the PLB 2, and when that digit is designated by the output of the PLB address counter 3, PLB data b is output. Print data a and PLB data b are the same. PLB data b is input to CG6,
Specify the block in which the character dot pattern corresponding to PLB data b is stored. This block consists of 8 bits in the horizontal direction and 8 bits in the vertical direction. The horizontal position information C consisting of 3 bits from the horizontal position control circuit 10 selects a horizontal dot pattern n of a certain character. This dot pattern consists of 8 bits in the vertical direction. Selecting dot information at a necessary vertical position from the vertical 8-bit dot pattern at a certain horizontal position output in this manner is realized as follows. Upon entering the print cycle, the vertical position control circuit 8 is set to vertical position 1. Thereafter, each time printing of one dot line in the horizontal direction is completed, the printing is advanced to the next dot line. At this time, the vertical position control circuit 8 is
The vertical position is increased by 2, and is specified sequentially starting from vertical position 2. Based on the vertical position information from the vertical position control circuit 8, necessary dot information can be selected from among the dot patterns at vertical positions 1 to 8 inputted to the data selector 7. If the output signal O of the data selector 7 has a logical value of 1, the hammer drive signal q has a logical value of 1, and the print hammer is driven to print a dot on the paper. As described above, characters such as alphabets, numbers, symbols, and katakana can be printed. Next, the control device of the present invention, which is used when printing figures and large characters, will be explained. When the printing device becomes able to receive print data from the host device 1, the data transfer start signal i becomes logical 1, and the print data a from the host device is transferred in the same way as when printing characters. . The print data a is 8 as shown in Tables 3 to 6.
It is made up of bits. Print data a is written to PLB2 by the synchronization signal. Further, the adder 4 is cleared to zero before transferring one dot line of print data a. Then, the number of logical values 1 among bits 1 to 6 of the transferred print data a is added and stored. When the print data a corresponding to the number of digits handled by one print hammer is transferred, the determination signal g becomes a logical value 1. At this time, the comparator 5 compares whether or not the revised result e of the adder 4 is greater than a predetermined value N, and the result is input to the NAND gate 11. When the addition result e is larger than N, the over N signal f
has a logical value of 1, and when it is small, it has a logical value of 0. A plot mode signal h indicating the plot mode is also input to the NAND gate 11 with a logic value of 1. Therefore, when the judgment signal g becomes a logic value 1, and the over-N signal f has a logic value 1, the flip-flop 12 is set and the 1 side output terminal of the flip-flop 12 becomes a logic value 1.
If the over-N signal f is a logic 0, flip-flop 12 remains in reset. After the judgment signal g becomes a logical value 1, the addition clear signal r becomes a logical value 1, and the previous addition result e
Clear and make it zero. After that, every time printing data a handled by one printing hammer is transferred, a judgment signal g and an addition clear signal r are sent.
becomes a logic value 1, and when the judgment signal g becomes a logic value 1, if the output e from the adder 4 is greater than N, the over-N signal f becomes a logic value 1, and the flip-flop 12 is set. Once the flip-flop 12 is set, the output terminal on the 1 side maintains the logic value 1 until the data transfer start signal i of the next row becomes the logic value 1. In other words, the reciprocating print signal l has a logical value of 1, and the received 1
Instructs to print dot lines in both directions. In other words, the logical value 1 from bit 1 to bit 6 of print data a written to PLB2 on the outward path
A dot is printed at the dot printing position corresponding to the dot print position, and the return trip is a pause period. (The reverse is also possible). After the 1-dot row data end signal becomes a logic 1, the printing device completes the data reception cycle and enters the print cycle. The print cycle is started in synchronization with the inversion signal. When entering the print cycle, PLB address counter 3 is activated and the 6-bit PLB from PLB2 is
The data b is input to the data selector 9, and the bit information of the current horizontal position is selected based on the horizontal position information C which is the output of the horizontal position control circuit 10, and is output as the signal p. Since the plot mode signal h has a logical value of 1, when the signal p has a logical value of 1, the output of the AND gate 21 has a logical value of 1, and when the signal p has a logical value of 0, the output of the AND gate 21 has a logical value of 0. That is, when the signal p has a logical value of 1, the hammer drive signal q has a logical value of 1, and the printing hammer is driven to print a dot on the paper. In this way, printing is performed during the one-way movement of the printing hammer group. On the other hand, the inverted signal counter 14 is cleared when the data transfer start signal i reaches the logical value 1, and the output k becomes zero. The print inversion signal j, which is the inversion signal after entering the print cycle, is counted by the inversion signal counter 14. The comparator 15 receives the output signal k of the inverted signal counter 14 and the reciprocating print signal l. The output of the comparator 15, that is, the print end signal m, is the inverted signal counter 1 when the reciprocating print signal l has a logical value of 1.
When the output k of the inversion signal counter 14 becomes 2, the logical value becomes 1, and when the reciprocating print signal 1 has a logical value of 0, when the output k of the inversion signal counter 14 becomes 1, the logical value becomes 1. That is, the comparator 15 generates a print end signal m every time an inversion signal j is generated during normal printing, and also generates a print end signal m when the number of prints is large and one round trip of the printing hammer group.
When printing a dot row, a print end signal m is generated when the inversion signal j is generated twice. Therefore, after entering the printing cycle and completing printing of one dot line by one-way movement of the printing hammer group, even if the printing inversion signal j becomes a logical value 1, the output signal k of the inversion signal counter 14 remains 1; Since the output of the comparator 15, the print end signal m, has a logical value of 0, the data transfer start signal i for starting reception of print data for the next dot row does not have a logical value of 1. The movement of the print hammer group is reversed and moves in the opposite direction to the direction of movement when printing was previously performed. The printing hammer group is paused until the printing inversion signal j becomes logical 1 again. Print inversion signal j has logical value 1
Then, the output k of the inversion signal counter 14 becomes 2, and the output of the comparator 15, the print end signal m, becomes a logical value 1. The printing device identifies that the printing end signal m has become a logical value 1, and sets the data transfer start signal i to a logical value 1 to inform the host device 1 that it is ready to receive the print data of the next dot row. As mentioned above, when the number of dots printed by one printing hammer is larger than the predetermined value N, one line of dots is printed during the one-way movement of the printing hammer group, and the one-way movement period for the return is repeated. The printing hammer and its driving circuit may be sufficient to print normal characters even in the worst case by stopping the printing hammer and its driving circuit. Therefore, the cooling device for preventing the heat generation of the coil of the printing hammer can also be small, and the device can be downsized and manufactured at low cost. When the number of dots printed with one printing hammer is smaller than N, printing is automatically enabled during the return one-way movement period, so the printing speed is not reduced. According to the present invention, there is no need to configure a printing hammer and its drive circuit to cope with the worst printing conditions, or to increase the size of a coil cooling device for the printing hammer, so the printing device can be made smaller and lighter. can be manufactured at low cost.

[Brief explanation of the drawing]

1 and 2 are front views showing examples of printing of normal characters and figures in the plot mode. FIG. 3 is a block diagram showing one embodiment of the control device of the present invention. 4 and 5 are timing charts for explaining the operation of FIG. 3, with FIG. 4 showing a data transfer period and FIG. 5 showing a printing period. In the figure, 1 is the host device, 2 is the PLB, and 3 is the
PLB address counter, 4 is adder, 5 and 15
is a comparator, 6 is a CG, 7 and 9 are data selectors,
8 is a vertical position control circuit, 10 is a horizontal position control circuit, 11 is a NAND gate, 12 is a flip-flop, 13 and 19 are inverters, 14 is an inverted signal counter, 20 and 21 are AND gates, and 22 is an OR gate.

Claims (1)

[Claims] 1. A plurality of printing hammers having dot printing elements are arranged side by side along the printing line, and these printing hammer groups are reciprocated in a direction across the printing paper,
In the process of this reciprocating movement, the printing hammer group is driven to print, and each reciprocation of the printing hammer group prints two dot lines, and the printing dot pattern of one dot line is transferred from the host device. a print data buffer for storing data; horizontal position indicating means for changing the value as the print hammer group moves in the row direction and generating an output corresponding to the moving position of the print hammer group; and print dots from the print data buffer. A selection means for outputting only print information at a horizontal position specified by a horizontal position signal from the horizontal position indicating means out of the pattern data; a reversal signal counter for counting a print reversal signal generated when the printing hammer group is reversed; , the count value of the inverted signal counter is input, and the count value is 1.
In a dot printing device equipped with a comparator that generates a print end signal when Counting means for generating a signal when counting, and control for controlling the comparator so that the comparator generates a print end signal when the count value of the inverted signal counter reaches 2 upon receiving the output signal of the counting means. A control device for a dot printing device, characterized in that the printing hammer group prints one line of dots in one reciprocation of the printing hammer group as a pause period in which printing is performed only when the printing hammer group is moving in the outward path, and printing is not performed during the backward movement.