JPH021677B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printing device using a dot matrix, and in particular, to improving printing quality without significantly increasing the storage capacity of a storage device required for character pattern generation. This is how it was done.

[Prior Art] Generally, in a dot matrix printing device,
A character pattern is used in which one character consists of 7 dots vertically x 5 dots horizontally or 9 dots vertically x 7 horizontally.For economic reasons, the print head is composed of the number of dots necessary to print one vertical column at the same time. One character was formed by printing by shifting the heads in one vertical column horizontally one dot at a time. For example, 1
In a character pattern consisting of 7 x 5 dots, the print head is made up of only the 7 pieces needed to print one line at the same time, and these seven heads in one vertical line are divided into 5 dots horizontally.
By shifting and printing twice, one character of 7×5 dots is formed. Also, when printing this,
For example, in a wire printer, there is a minimum cycle time required to print one dot, such as the time required for the wire to move back and forth through the plunger, and in a thermal printer, for example, the heat generation time and heat dissipation time. . Normally, in order to maximize printing speed, the clock is set so that horizontally adjacent dots are printed at this cycle interval.

Here, FIG. 1A shows a character pattern expressing the alphabet "W" using a dot pattern of 7 vertically x 5 horizontally using the above-mentioned conventional normal printing method. The continuity of the dots in the diagonally lined areas was poor, causing a decline in print quality. In order to eliminate this drawback, it is possible to increase the number of dots per character by making the dot matrix smaller and eliminate the unnaturalness of the diagonal line part, but if the dot matrix is made smaller, it is possible to memorize character patterns. The number of bits in the device has increased significantly, and even if the matrix is made finer, the printing quality cannot be improved unless the dot size, blurring, density, etc. are controlled at a higher level, so the configuration of the printing section is becoming more complex. Furthermore, the control section for driving and controlling the printing section becomes complicated, leading to various problems such as a significant increase in manufacturing costs.

Therefore, in order to improve the printing quality compared to conventional devices of this type without making the dot matrix per character finer, the conventional print head drive control, which shifts horizontally one dot pitch at a time, has to be shifted horizontally half a dot pitch at a time. It is conceivable to shift it to . At this time, as long as the condition that ``do not print horizontally adjacent half dots'' is set, it is possible to print even in the middle position between the regular dot positions in the horizontal direction, using the printing unit, drive unit, etc. as before. For example, in a dot matrix of 7 vertical x 5 horizontal dots, 4 dots can be printed at the middle position of the normal position of 5 dots horizontally, and the dot matrix forming one character increases to 7 x 9 horizontal dots.

[Problems to be Solved by the Invention] However, it is not economical to continue using a character generator with an increased number of dots in the horizontal direction, as described above, because of the large degree of redundancy. The reason for this is that due to the above-mentioned condition ``half dots are not printed side by side'', dots at the normal position and dots at the intermediate position are not printed next to each other in the same line, and dots at half pitch do not print side by side. This is because only part of the bit information is used. However, in each line of a dot matrix that generally represents a character pattern, if a dot is printed at a half-dot pitch position, there is a very high probability that other dots in the same line will also be printed at a half-dot pitch position.

The present invention has been made with attention to these points, and by providing a 1-bit shift instruction bit corresponding to each row of the dot matrix and specifying the row in which dots are to be printed at half-dot pitch positions, It is an object of the present invention to provide a dot matrix printing device capable of improving printing quality without significantly increasing the storage capacity of a storage device required for character pattern generation.

[Means for solving the problems] In order to achieve such an object, the present invention has the following features:
In a printing device that performs printing by moving a print head in pitches of a predetermined distance, a first storage means for storing pattern information to be printed, and each of the pattern information stored in the first storage means are stored at a pitch of a predetermined distance or less. a second storage means for storing instruction information for instructing a part to be printed by moving the print head in distance pitches; and a second storage means for storing instruction information for instructing a part to be printed by moving the printing head in distance pitches; The present invention is characterized by comprising a print control means for performing printing by moving the print head by a distance pitch less than or equal to a predetermined distance pitch at a location indicated by the instruction information stored in the second storage means in the information.

[Function] According to the present invention, dots can be printed even in the middle of the normal dot position by simply adding a shift instruction bit to the character generator, so the shift instruction can be printed without modifying the head or head drive unit. Print quality can be significantly improved simply by increasing the storage capacity for storing bits.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an embodiment of the invention, where 1
2 is a timing signal generation circuit, and 2 is a read-only memory, for example, which stores character dot pattern data and shift instruction bits for instructing the line in which dots are to be printed at half-dot pitch positions for each line of the matrix. It is a character generator. 3
4 is a latch, 4 is a head driver, and the character generator 2 is controlled by the control signal of the timing signal generator 1.
Shift instruction bits and dot patterns are supplied to latch 3 and head driver 4, respectively. Furthermore, the head driver 4 operates the head 5 based on the information of the shift instruction bit supplied to the latch 3 by the control signal of the timing signal generating circuit 1.
to drive and control. Also, 6 is a shift register, 7
is a motor driver; 8 is a motor for driving the head 5; the motor driver 7 drives the motor 8 in accordance with a control signal sent from the timing signal generating circuit 1 via the shift register 6;

Next, the operation for printing the letter "W" will be described. The character generator 1 stores the above-mentioned shift instruction bits together with the dot pattern representing the printed character "W". For example, as shown in FIG. This is a shift instruction bit part that controls whether or not to print at the half dot pitch position, and is set to “1”.
"0" corresponds to the fact that dots should be printed, and "0" corresponds to the fact that dots are not printed. Now, when a readout signal for the print "W" is sent from the timing signal generation circuit 1 to the character generator 2, the shift instruction bit section 12 is first read out and stored in the latch 3, and at the next timing, the shift instruction bit section 12 is read out and stored in the latch 3. A column is read from the character generator 2 and sent to the head driver 4. The head 5 is controlled by the head driver 4 to start printing at the regular dot positions in the first row of the pattern section 11. At this point, the head driver 4 is controlled by the shift instruction bit information stored in the latch 3. Then, a predetermined row in the first column of the pattern section 11 corresponding to "0" of the shift instruction bit information is printed. That is, in the first column of the pattern section 11 shown in FIG. 3, the second bit from the bottom row is not printed because the corresponding shift instruction bit information is "1". Next, the timing signal generating circuit 1 generates a control signal to move the head 5 to the right by half a dot pitch. Here, head 5
If the drive motor 8 is driven in four phases using a normal pulse motor, the above-mentioned control signal is supplied to the shift register 6 as a shift pulse input, and the next four-phase signal is output from the shift register 6. The signal is supplied to the motor driver 7 to drive the motor 8, and the head 5 moves to the right by a half dot pitch. Next, the timing signal generation circuit 1 sends the next timing signal to the head driver 4 to select the first column of the pattern section 11 corresponding to "1" among the previous shift instruction bit information already stored in the latch 3. Print only the line. That is, the third
In the first row of the illustrated pattern section 11, only the second bit from the bottom is printed by being shifted by a half dot pitch to the right from the regular dot position in the first row.
Next, in the same manner as described above, the motor 8 is driven by the timing signal supplied from the timing signal generation circuit 1 again, and the head 5 is shifted to the right by half a dot pitch and set at the regular dot position in the second column. Ru.

In this way, the printing operation for the first column of the dot matrix is completed, and thereafter, the rows at the "0" position of the shift instruction bit information are printed in the same manner from the second column to the fifth column, and the rows at the "1" position are similarly printed. By repeating the printing operation in sequence while shifting the head half a dot pitch at a time, the printing operation for the dot matrix constituting one character is completed, and the letter "W" as shown in Figure 1B is printed. Ru.

FIG. 4B shows the character "Y" printed in the same manner as described above, and the continuity of the hatched area is better than in the example of printing by this type of conventional printing method shown in FIG. 4A.
It can be seen that the character quality is significantly improved.

[Effects of the Invention] As explained above, according to the present invention, the structure is such that dots can be printed even in the middle of the regular dot positions by simply adding a shift instruction bit to the character generator, so that the head and head drive unit, etc. Printing quality can be significantly improved simply by increasing the storage capacity for storing shift instruction bits without modifying the printer.

[Brief explanation of drawings]

1A and 4A are diagrams showing two examples of printing by a conventional dot matrix printing device.
Figures B and 4B are diagrams showing two examples of printing by the printing device of the present invention, Figure 2 is a block diagram showing one embodiment of the printing device of the present invention, and Figure 3 is a diagram showing the characters stored in the character generator. FIG. 2 is a diagram showing an example of a bit matrix representing a character pattern. 1... Timing signal generation circuit, 2... Character generator, 3... Latch, 4... Head driver, 5
... head, 6 ... shift register, 7 ... motor driver, 8 ... motor, 11 ... dot pattern section, 12 ... shift instruction bit section.

Claims (1)

[Scope of Claims] 1. A printing device that performs printing by moving a print head a predetermined distance in pitch, comprising a first storage means for storing pattern information to be printed, and a first storage means for storing pattern information stored in the first storage means. For each, a second storage means for storing instruction information for instructing a part to be printed by moving the print head at a distance pitch equal to or less than the predetermined distance pitch, and reading out pattern information stored in the first storage means. printing control means for printing by moving the printing head by a distance pitch equal to or less than the predetermined distance pitch at a portion of the pattern information to be printed indicated by the instruction information stored in the second storage means; A printing device characterized by comprising: