JPS63207655A - Printing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a printing method for a printer such as a wire dot printer that prints in a dot matrix format, and relates to a printing method suitable for reducing noise and improving the sound quality of generated sounds. .

[Conventional technology]

BACKGROUND ART In impact printers such as wire dot printers, when printing elements such as magnets and wires are driven to fly the wires and print on printing paper, the striking action of these elements generates a large amount of noise.

Furthermore, even in non-impact printers such as pulse-jet inkjet printers, when the ink capacitance of the print head is deformed by a piezoelectric element, high-frequency noise is also generated along with the deformation operation.

Conventionally, in order to prevent the generated acoustic energy from being emitted into the external space where the operator is located, these printers have used sound insulating covers, or taken sound and vibration-proofing measures such as preventing vibrations of printing elements or surrounding structures. It had been taken.

Additionally, measures have been taken to disperse the timing of driving the printing elements so that large amounts of acoustic energy are not generated at the same time.

An example of implementing the above-mentioned measures is 5, for example, Japanese Patent Application Laid-open No. 5
As disclosed in Japanese Patent No. 3-102124 and Japanese Patent No. 54-98822, by shifting the interval between the dot printing elements in the plurality of rows from the interval between the printing pixels, it is possible to avoid the dot printing elements in the plurality of rows from operating at the same time. The noise generation has been reduced by averaging the movements.

[Problem that the invention seeks to solve]

However, in these methods, the interval between printing pixels is a unique value determined by a dot matrix pattern generator (also called a character generator), and the number of operations per unit time of the dot printing element is The same is true for dot printing elements. Therefore, when printing a character pattern with many consecutive dots, such as kanji characters or ruled lines, using this method, many dot printing elements operate continuously at almost the same time, resulting in significant noise generation. Among the frequency components of noise, large and prominent values are distributed at certain specific frequencies, causing discomfort to human hearing.

This situation will be explained in more detail using FIG.

FIG. 6(a) shows the wire arrangement of the print head of a wire dot printer, with 12 wires arranged in each column A and B, and the interval between these two columns. is a2. of the square mesh character pattern shown in Figure (b). b3. a6. There is a long continuous dot row in terms of character design in the a8°b9 rows, and when the dot printing element prints them, it operates repeatedly and continuously at the minimum operating cycle.

The timing of this operation is shown in FIG. Since the interval between columns A and B in the wire arrangement of the print head is 7.5 dot pitch, the driving timings of columns A and B are shifted by 172 cycles as shown in the figure. The basic driving period (T) of continuous dots in both the A column and the B column is the same.

FIG. 8 shows the results of frequency analysis of the average measurement of noise generated when such character patterns are continuously printed. In this example, there are parts in the audible frequency band that exhibit extremely large values. They are the continuous dot fundamental frequency f, (f□=
1/T) and the harmonic f, which is an integer multiple of the frequency
n (f n = n / T - n = 2, 3, 4, 5,
6) and 1/2 subharmonic f172 etc. is Il!
be measured.

When we analyze this in relation to the operation of the dot printing element, we find that
As understood from the operation timing shown in FIG.
It can be seen that the noise generated when rows and rows B operate almost simultaneously is the loudest, and its frequency is n times the continuous dot frequency. The noise of this frequency component is all related to one overtone, so to the human auditory sense, especially the sense of pitch (pitch), it sounds like a single high-frequency sound and is extremely unpleasant to the ears. Furthermore, since the frequency is high, it increases discomfort.

The present invention has been made in view of the above circumstances, and its purpose is to solve the above-mentioned problems in conventional printing methods, and to print printing elements at several different continuous dot frequencies almost simultaneously. By operating it, it is possible to disperse the outstanding values of specific frequencies of the generated noise, and to make those frequencies acoustically in a harmonic relationship, making it possible to change the noise in a direction that eliminates discomfort. The objective is to provide a printing method that

[Means for solving problems]

The above-mentioned object of the present invention is to provide a print head having a plurality of print elements, and to selectively operate the print elements while relatively moving the print medium in a predetermined direction to print information on the print medium in the form of a combination of dots. In a dot matrix printer that prints.

This is achieved by a printing method characterized in that the number of operations per unit time of the plurality of printing elements is independently variable.

Furthermore, acoustically, in order to improve the sound quality of the noise, by selecting a specific ratio of operating frequencies for each printing element, harsh sounds can be reduced and a pleasant sensory sound can be achieved.

[Effect]

In character patterns such as ordinary kanji characters, there are several straight lines, ie, a series of dots, in one character. In the conventional printing method, the dot pitch P of continuous dots is a constant value, and when there is a gap between dots, the value is an integral multiple of that value.In contrast, in the printing method of the present invention, the dot pitch P of continuous dots is a constant value. By converting the dot density using a character pattern generator with different densities or a specific algorithm, the dot spacing between successive dots is set to a plurality of predetermined values.

For example, if there are five consecutive dot rows in the horizontal direction in one character, the dot spacing of any two of them is set to the same dot pitch P as before, but the remaining three
The dot spacing of a book's dot row is, for example, dot pitch 1
．． It is set to 25P.

The timing of driving the printing elements when printing this character pattern is controlled using, for example, a variable timer that operates at a cycle corresponding to each dot pitch.

When printing a continuous dot row with a dot pitch P, a timing pulse with a timer period T is used. in this case,
The continuous dot fundamental frequency is f ai =-, and the frequency components of the generated noise are as described above, f66 =
A frequency band of (n=e1.2.3...) appears as a dominant component.

Further, when printing continuous dots with a dot pitch of 1.2SP, the timer period T' is set to T'=□. In this case, continuous dots 1.25
7 (n= *1e2*3*...) frequency bands appear as dominant components.

By dividing the dot spacing between successive dots into one in this way, it is possible to disperse the dominant frequency components of the noise. In addition, in the case of a dot row with a continuous dot pitch of 1.25P, the dot density printed per unit time is also lower than that of the conventional dot pitch P, so the value of the dominant component of the generated noise is also low, and the noise is reduced. The acoustic energy itself is also reduced, making it possible to reduce annoying noise.

That is, independently changing the dot frequencies of the printing elements that print continuous dots at almost the same time has the effect of dispersing the dominant noise components and reducing their values themselves.

Next, we will discuss the acoustic relevance of frequency. The frequencies of the dominant components in the case of the above-mentioned dot pitch P and 1.2SP are arranged in descending order, and
When the continuous dot fundamental frequency fI of SP is set to 1, the ratio of each frequency is determined as shown in FIG.

In acoustics, the distance between two sounds (pitch (frequency)) is called pitch. Also, two tones that harmonize when sounded at the same time are called consonant intervals. There are many types of consonant intervals, but a representative example is two tones with a frequency ratio of 4 = 5, i.e., one is the reference tone, and the interval soul is an integral multiple of 5/4. This is called a third degree, and when these two notes occur at the same time, they produce a stable and pleasant resonance.

In the case of the above example, if we consider the fundamental frequency fbt of the dot row with a dot pitch of 1.2SP as a reference, each frequency shown in FIG. It shows that there is a pitch relationship,
It can be seen that it serves as a pleasant sensory platform for the listener.

This relationship was created by the selection of the dot frequency of the printing element that prints continuous dots almost simultaneously.
This was created by selecting the dot pitch of the dot array with a dot pitch of P, which is a quadruple frequency fa4 of the fundamental frequency fat, and the dot array with a dot pitch of 1.25P, which is a fifth frequency of the fundamental frequency fbt. That is, controlling the dot frequencies of printing on the continuous drum 1 for a plurality of printing elements so that their high-order frequencies coincide has the effect of making the generated noise have a consonant interval relationship and making it sound pleasant.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram showing an example of a character pattern used in a wire dot printer, etc., as an embodiment of the present invention. In this example, compared to what was shown earlier in FIG. 6(b), columns a'2 and a'6 are the same, but b'3.
a'8. The dotch bits of the continuous dot rows of b'9 are different. That is, in Fig. 6(b), row b3 is a series of 14 dots, row 88 is a series of 15 dots, and column b9 is a series of 17 dots, and the dot pitch of these consecutive dots is the same as the others, P is constant. However, in Fig. 2, row b'3 is a series of 11 dots, row a'8 is a series of 12 dots, and column b'9 is a series of 14 dots, and the dot pitch of these consecutive dots is P. '=1.25P.

Incidentally, the a'2 column and the a'6 column are continuous 16 dots and 13 dots, respectively, and the dot pitch thereof is P.

An example of printing such a character pattern using a print head having the wire arrangement shown in FIG. 6(a) will be described next.

FIG. 1 is a block diagram of a printer control section showing one embodiment of the present invention. In the figure, 1 is a control unit that controls each part of the printer control section.

2 is an interface control unit that controls the connection between the printer and other devices; 3 is a code buffer that is a storage means for temporarily storing the print character information sent from the host device; and 4 is a dot matrix pattern that stores the print character information code. A generated character generator (Ca) is shown.

Further, 5 operates in conjunction with the control unit 1, and has a function to identify dot continuity, such as how dots are continuous in which column, etc., with respect to the dot information of the character generator 4. A table that stores character pattern conversion rules as an algorithm for how to convert continuous dots in a column, a function to output the converted dot pattern according to the contents of the table, and a function to print from any position and at what timing. This figure shows a dot pitch control unit that is equipped with a table that stores position and timing information such as whether to drive an element as an algorithm, arithmetic functions, and the like.

6 is a total of 24 printing magnets 7a-1 to 7b-12
The printing head is a printing head having a number of drive elements, each of which drives a corresponding printing wire (not shown) to print the dot rows a1 to b12, and the printing magnet 7a-1 7b-12 are configured to be independently driven by drivers 8a-1 to 8b-12. Reference numeral 9 indicates a variable timer which is interlocked with the control unit 1 and sends a timing pulse having a drive cycle matching the dot pattern determined by the dot pitch control section 5 to the drivers 8a-1 to 8b-12.

Various types of character generators can be used as the character generator 4 described above. For example, as shown in FIG. Alternatively, a conventional square mesh dot pattern memory element as shown in FIG. 6(b) may be used. In the former case, the dot pattern has been converted in advance, so
Although it is not necessary to convert the dot pattern each time printing is performed, the pattern is fixed, so if you want to use various patterns arbitrarily, prepare multiple types of character generators 4 in advance. It is necessary to do so.

In the example described below, we will take the latter case as an example.

The operation of this embodiment configured as described above will be explained below.

From the interface control unit 2, the print character code, for example,
Assume that a printed character code corresponding to "Kan" is stored in the code buffer 3. The control unit 1 calls the dot pattern of "Kan" from the character generator 4 and executes a printing operation. In this case, the control unit 1 first
The conventional standard dot pattern shown in FIG. The dot pitch control unit 5 decodes the information and reads a'Lb'3ta'6. a'8. b'9
Identify that there is a long continuous string of dots in each column of , and also
Identify the number of consecutive dots, the starting point position, and the ending point position.

Next, these continuous dot strings are converted using a predetermined algorithm. In this example, since there are five continuous dot strings, three of these continuous dot strings are converted.

The above algorithm will be explained assuming that the dot pattern called from the character/lid generator 4 is decoded and information as shown in FIG. 5(a) is obtained. The continuous dot presence/absence information 10 in a) is as follows:
When the number of consecutive dots is equal to or greater than a predetermined amount (here, 12 dots), "1" is assigned as ``continuous dots present'', and when it is less than the predetermined amount, ``0'' is assigned as ``no consecutive dots''. Using the bit pattern of the continuous dot presence/absence information 10 as a key, the conversion table 11 shown in FIG. 5(b) is searched.

The conversion table 11 extracts a dot sequence whose dot pitch is to be converted from a continuous dot sequence, and converts half (N
If is an odd number, it is created to convert (N+1)/2), and which column is to be converted is, for example,
A method of converting the number of upper dot rows, or a method of alternately combining columns to be converted and columns not to be converted among continuous dot rows as in the fifth embodiment may be freely selected when creating the table.

As in this example, a'2, b'3, a'6
, a'8, and b'9, the bit pattern of continuous dot presence/absence information 10 is changed to a'
When expressed in hexadecimal with 1 as the lower bit and b'12 as the upper bit, it is (048844)□.

Then, use this value as a key to search the conversion table 11.
48844), the dot pitch is changed in advance so that the dot string corresponding to the bit that is '1'' among the six bits of information from which the dot pitch conversion information 12 stored is obtained is the dot pitch conversion information. A method is used in which desired values are stored in the control section 5 as a table, or a method is calculated according to the number and length of continuous dot strings.

In addition, as for what kind of dot pitch to convert, a method is used in which desired values are stored in advance as a table.In the case of this embodiment, when the original dot pitch was P, I am planning to convert it to .25P.

As mentioned above, the dot pattern shown in FIG. 6(b) is converted into the second dot pattern shown in FIG. The drivers 8a-1 to 8b-12 operate sequentially to perform printing.

Next, printing timing will be explained. When the dot pattern is converted, the dot pitch to be printed changes, so it is necessary to change the timing of driver drive according to the dot pitch.In the case of this embodiment, a'2. Regarding the continuous dot part in row a'6, the dot pitch is P, so the period of the drive timing pulse may be T, but b'3, a'8
, b' For the nine rows of continuous dots, the dot pitch is 1.2SP, so the period of the drive timing pulse needs to be 1.25T.

These timing pulses with different periods are generated by the variable timer 9. When the information from the dot pitch control section 5 is sent to the variable timer 9, the variable timer 9 sends out timing pulses at the necessary pulse intervals to the drivers 8a-1 to 8b-12 at the necessary time according to the information.
Printing is performed from a predetermined position at a predetermined dot pitch.

Examples of these timing pulses are shown in FIG. 3. In this example, when printing 88 consecutive dot rows, the timing pulses of row A are used, and the timing pulses of row A are used. The timing pulses of the B column are used for the b'9 column, the A timing pulses are used for the other a' columns, and the B column timing pulses are used for the other b' columns.

In the case of the above example, a'2, b'3, a'6
, a'8, b'9, etc., various periods of the printing element 2 z are mixed almost simultaneously. In addition to the surrounding noise generated when printing at these cycles, 1/2 subharmonics and n-th harmonics appear as dominant noise components. There is a relationship between these. The frequency characteristics of such noise are shown in FIG.

The frequency components shown in Figure 4 have the same relationship as shown in Figure 9 earlier, and as mentioned above, these frequencies have a consonant interval relationship with each other, so they are pleasant sensory sounds for humans. This has a great effect on noise reduction. In addition, in the case of this example, since the density of the dot pattern is reduced, the number of dots per unit time is also reduced, so the generated acoustic energy is reduced and the noise level itself can be reduced. , which has a great effect on noise reduction.

Next, another embodiment of the present invention will be described.

In the case of the above embodiment, the dot pitch is P and 1.2.
Although I have chosen 5P for my explanation, from an acoustic point of view there are many other frequencies that create consonant intervals.

An example will be explained below.

Acoustically, as an interval for forming a chord, there is a perfect fifth interval with a frequency ratio of 2:3. If this interval is included in the interval relationship of the first embodiment described above, it becomes possible to make the sound even more resonant. In the above embodiment, a cycle of 1.25T was considered, but the drive cycle at which the frequency here and there is in the above 2:3 relationship is T, =
-.1.25T, since this value is smaller than T, it becomes necessary to drive the printing element faster than the conventional speed.

This value can be used if there is margin for the maximum operating speed of the printing element, but if not, the value will be twice the above T0, that is, T0 = 2 - 1.25T to 1.67T, The dot pitch is 1.67P.

When arbitrary dot rows of the continuous dot rows of the first embodiment described above are operated simultaneously at this dot drive cycle, the frequency of the noise generated by the dot rows becomes 1/2 subharmonic, n-th harmonic, etc. It will appear as a prominent ingredient. These have the following relationship.

If the frequency sequence is added to that shown in FIG. 9 and rearranged, a frequency sequence as shown in FIG. 1O is obtained. These frequency sequences are the reference frequency fb& and its harmonics, and the reference frequency and 4:5
In other words, it has a relationship with the major third interval and the standard frequency of 2=3, that is, a perfect fifth interval, and its overtones. Acoustically speaking, a chord in which these frequencies occur almost simultaneously is called a major triad, and it produces the most stable sound as the so-called C, E, and G chords.

In the case of the above embodiment as well, the frequency fbs is five times the fundamental frequency fb□ of dot pitch 1.25P, and the frequency f is four times the fundamental frequency fa1 of dot pitch P. 4 matches,
In addition, the fundamental frequency fcl of dot pitch 1.67P is 4
Double frequency f. 4 and the triple frequency fba of the fundamental frequency fbt with a dot pitch of 1.2SP match. In other words, by controlling the driver frequency of continuous dot printing for multiple printing elements so that their high-order frequencies match, it is possible to make the generated noise resonate as a pleasant and stable chord. This is highly effective in improving the sound quality of noise.

Next, the printing speed and printing quality in each of the above embodiments will be described.

Regarding the printing speed, since the operating cycle of the printing element is less than the minimum operable cycle, the printing speed does not decrease.

Regarding printing quality, in the conventional method, all consecutive dot pitches were uniformly P, but in this embodiment,
In addition to P, 1.25P and 1.67P are partially used for the dot pitch.Normally, in a 24-wire wire dot printer, P=0.141m (1/1
80 inches) is used. In this case, the diameter of the printing wire is 0.2g+nφ, and when printing is performed via the ink ribbon, the diameter of the printed dot is approximately 0.
．． It will be about 25 mmφ.

The dot pitch 1.25P is 0.176mm, and the same 1
．． 67P is 0.235■■, which is smaller than the printed dot diameter of 0.25a-φ, so even if the dot spacing is wider than before, consecutive dots will not be separated. , there will be no loss of continuity as a straight line and no deterioration of print quality.

Furthermore, depending on the design of the dot pattern, the positions of the start and end points of continuous dots may deviate from the conventional square mesh dot pattern, but this size is less than or equal to the size of the entire character. 1 /23 (24X
In the case of a 24-dot matrix), the size is not large enough to degrade character design quality, but is within an acceptable range.

Therefore, it is possible to obtain much better printing quality than the rough printing quality such as draft printing, which usually sets all dot pitches to 2P and increases the printing speed in order to achieve low noise with wire dot printers.

In the present invention, the selected dot pitch determines the frequency component of the generated noise.

This means that depending on how you select the dot pitch, the chord relationship of the generated notes will change. There are many other chords that produce an acoustically pleasant sound, including minor triads, and in order to be able to arbitrarily select one of these chords, the dot pitch control section 5 is programmed in advance to
This is possible by preparing multiple algorithms for how to convert the dot pitch.

It goes without saying that the tone can be changed depending on which dot pitch is converted to which part of the continuous dot string in a single character pattern, and it is possible to change the tone by converting only the part of the long continuous dot string described in the above example. Needless to say, it is also possible to convert a shorter dot string.

As described above, the present invention can be applied not only to impact printers but also to pulse-jet type ink-jet printers that eject ink by deforming an ink cavity through the operation of a piezoelectric element, and the like.

〔Effect of the invention〕

As described above, according to the present invention, a print head having a plurality of printing elements and a printing fiber are selectively operated while relatively moving in a predetermined direction to form dots on the printing medium. In a dot matrix printer that prints information consisting of a combination of By operating it, it is possible to disperse the outstanding values of specific frequencies of the generated noise, and to make those frequencies acoustically in a harmonic relationship, making it possible to change the noise in a direction that eliminates discomfort. This has the remarkable effect of making it possible to realize a printing method that does.

In addition, the number of operations of printing elements per unit time is wt
4-J, it is possible to reduce the acoustic energy generated and the sound pressure level of the noise, which is highly effective in reducing noise from printing elements and improving sound quality.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a printer control unit showing an embodiment of the present invention, FIG. 2 is a diagram showing a character pattern of the embodiment,
Fig. 3 is a diagram showing the dot drive timing of the printing method of the embodiment, Fig. 4 is a diagram showing an example of the frequency characteristics of printing noise in the printing method of the embodiment, and Fig. 5 is a configuration diagram showing details of the dot pitch control section. , FIG. 6(a) is a diagram showing the wire arrangement of the print head of a conventional wire dot printer, FIG. 6(b) is a diagram showing the character pattern, FIG. 7 is a diagram showing the dot drive timing of the conventional printing method, and FIG. FIG. 8 is a diagram showing an example of the frequency characteristics of printing noise in a conventional printing method, and FIGS. 9 and 10 are diagrams showing the dominant frequency distribution of generated noise in the embodiment. 1: control unit, 2: interface system f11 section,
3: Code buffer, 4: Character generator, 5
: Dot pitch control section, 6: Print head, 7a-1 to 7
b-12: Printing magnet, 8a-1 to 8b-12: Driver, 9: Variable timer, IO: Continuous dot information presence/absence information, 11: Conversion table. Figure 2 PL, 25T' δ Figure 4 2K 4K 6K 8K
IOK frequency (Ilz > Fig. 5 Fig. 6 (a) (b) Fig. 7 Fig. 8 Frequency (IT2)

Claims (1)

[Claims] 1. A print head having a plurality of print elements, and a dot matrix that prints information consisting of a combination of dots on the print medium by selectively operating the print elements while relatively moving the print medium in a predetermined direction. A printing method in a printer, characterized in that the number of operations of the plurality of printing elements per unit time is independently variable.