JP3243757B2 - Print head drive method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) In the present invention, print pins are arranged at a natural number multiple of a predetermined distance in the transport direction of the print head or at a natural number multiple of 1/2 of the predetermined distance. And a print head driving method in a dot matrix printing apparatus.

2. Description of the Related Art Conventionally, the interval between print pins in a print head of a dot matrix printing apparatus is configured to correspond to the basic dot pitch of the printing apparatus.

For example, in the most common 24-pin kanji printer, the basic dot pitch (Pv) is 1/180 inch, and the print pin is set in the print head transport direction X as shown in FIG. The print heads are arranged at an interval of a natural number multiple of the dot pitch (Pv) or a natural number multiple of 1/2 of the predetermined distance, and drive the print head at a dot pitch of 1/180 inch.

The advantage of the conventional method as described above is that the printing pin interval is set to a natural number multiple of the dot pitch for each even-numbered printing pin / odd-numbered printing pin, and that the printing head is driven at the dot pitch. According to the timing shown in FIG. 3, the 24 drive coil 12-phase excitation
It is sufficient to excite even-numbered printing pins and odd-numbered printing pins at the same time. For driving, if only two types of phase signals are prepared, printing is possible, and the timing configuration is simple and easy to understand. .

Here, in FIGS. 2 and 3, the numerals indicate the print pin numbers when the print pins are numbered.

(Problems to be Solved by the Invention) However, according to the above-described related art, a maximum of 12 print pins are simultaneously driven at one print timing.

As a result, many print pins are driven simultaneously,
There is a problem that noise due to the impact increases. Furthermore, there is another problem that, when the print pins adjacent to each other in a specific positional relationship are driven at the same time, magnetic interference occurs between the drive coils and the driving force of the print pins is weakened. Furthermore, the above 2
In order to solve the above problems and to secure a predetermined driving force, a larger driving power is required.Moreover, since a large number of printing pins are driven at the same time, the power required at one time increases, and noise also decreases. There was also a problem of becoming large.

The present invention solves the problem of magnetic interference and simultaneously reduces the number of simultaneously driven printing elements, thereby reducing the number of simultaneously driven printing elements even in a dot matrix printing apparatus equipped with a printing head of a configuration widely and generally used. It is an object of the present invention to provide a print head driving method capable of reducing the driving power required for the printing and the noise.

(Means for Solving the Problems) The present invention provides an interval which is a natural number multiple of a basic dot pitch Pv, which is a dot pitch in a direction perpendicular to the transport direction of the print head, or a natural number multiple of 1/2 of the Pv. A printing head driving method capable of suitably performing printing driving in a dot matrix printing apparatus equipped with a printing head having a configuration widely used in the past, in which printing elements are arranged at intervals and in the direction of transport of the printing head. The printing head is driven by setting the interval X having a relationship of Pv / 2 <X <Pv as a basic driving pitch in the printing head transport direction.

Further, in the above-described print head driving method, the print head is configured so that dots continuous in the transfer direction of the print head are not printed at the basic drive pitch X interval but are printed at twice the basic drive pitch X interval. It may be driven.

Further, in the above-described print head driving method, a print head formed so that a locus formed by connecting the arrayed print elements is substantially rhomboid in a plan view may be used.

(Operation) In the print head driving method of the present invention as described above, the print elements are arranged in the transfer direction of the print head at intervals of a natural number multiple of the basic dot pitch Pv or a natural number multiple of 1/2 thereof. In a dot-matrix printing apparatus equipped with a print head of a configuration that has been widely and conventionally used, print pins at a position that is a natural number multiple of the interval X having a relationship of Pv / 2 <X <Pv are simultaneously driven. Therefore, adjacent printing elements having a specific positional relationship are not driven simultaneously, so that the problem of magnetic interference is solved and the electric power required to obtain a predetermined driving force is reduced. In addition, since the number of printing elements that are driven simultaneously is reduced, the power consumption required at a time is reduced, the power consumption is evenly distributed over the entire printing period, and noise during printing is reduced.

Further, if the print head is driven so that dots continuous in the transport direction of the print head are not printed at the basic drive pitch X interval but at twice the basic drive pitch X interval, [X <Pv Since the relationship <2X <2Pv] holds, printing can be performed at approximately 1.5 times the speed of printing with the conventional interval Pv, and the interval X is used in the relationship between the transport direction of the print head and the adjacent dots in the vertical direction. Since printing is possible, high-resolution and high-speed printing can be performed.

(Examples) Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is a print pin drive timing diagram when an embodiment of the method of the present invention is applied.

The print head of this embodiment has print pins arranged in the same manner as the above-described conventional print head shown in FIG. That is, in the case of the print head of the most common 24-pin Chinese character printer, the basic dot pitch (Pv) in the direction perpendicular to the print head transport direction is 1/180 inch. With this as a basic unit, the interval between adjacent print pins in the print head transport direction X is set. That is, as shown in FIG. 2, the printing pins are spaced by a natural number multiple of the basic dot pitch (Pv) in the transport direction of the print head in the basic unit of the basic dot pitch (Pv), 1/180 inch, or Distance
They are arranged at intervals of 4 times a natural number times 1/2.

Printing pin spacing of the print head drive direction was set to 4.5 / 180 inch half integer multiple of example Ph ₁ Basic Doddopitchi (Pv = 1/180 inches), Ph ₂ basic dot pitch (P
v) Set to 4/180 inches, which is an integral multiple of v), the print head transport direction interval (Ph ₂ ) between even-numbered pins and odd-numbered pins becomes an integral multiple of the basic dot pitch (Pv) and prints Except between pins 11 and 13, and between pins 12 and 14, the print head transport direction interval (Ph ₁ + nPh ₂ : n is a positive integer) between even-numbered and odd-numbered The difference between the adjacent even-numbered print pins or the odd-numbered print pins in the print head transport direction interval (Ph ₂ ) should be 0.5 / 180 inches, which is half the basic dot pitch (Pv). The print pin is located at (for example,
As shown in FIG. 2, the distance between the pins 5 and 6 in the print head transfer direction is Ph ₁ + 3Ph ₂ , and the distance between the pins 5 and 7 in the print head transfer direction is Ph _2. Ph ₁ + 2Ph a ₂ = 12.5 / 180 inch out a difference in units 0.5 / 180 inch). Further, the trajectories formed by connecting the print pins 1 to 24 are arranged so as to substantially form a rhombus.

On the other hand, the print head in this embodiment is driven at a dot pitch of 1/240 inch, which is smaller than the basic dot pitch of 1/180 inch.

Since the print head is driven at a dot pitch different from the basic dot pitch, a print timing signal to be generated while moving the print head can be set as shown in FIG. In the example shown in FIG. 1, the 24 drive coils for individually driving the print pins are excited like 24 drive coil 8-phase excitation.

In other words, at the timing when the print pin number 1 is excited, the print pins located at the position of a natural number multiple of 1/240 inch are simultaneously enabled. Specifically, the print pins of numbers 2, 7, 8, 17, 18, 23, and 24 can be operated. Also, at the timing when the print pin number 3 is excited, the print pins 6, 9, 12, 14, 15, 20, 21 at the position of a natural number multiple of 1/240 inch are similarly operable. At the timing when the number 4 is excited, the print pins 5, 10, 11, 13, 16, 19, and 22 at the position of a natural number multiple of 1/240 inch are also operable. As a result, the print pins having a positional relationship that may cause magnetic interference are not driven at the same time, and the eight print pins are simultaneously driven three times at different timings.

Therefore, at a specific timing, the number of print pins that are simultaneously driven can be up to eight pins. As a result, only two-thirds of the conventional 12 pins are required.

In the above-described embodiment, in order to drive a print head having print pins arranged with a basic dot pitch of 1/180 inch at a pitch different from the basic dot pitch,
Printing is performed at a printing speed different from the case of driving at the basic dot pitch.

Further, in this embodiment, by preventing continuous dots in 1/240 inch units from being printed, they are treated as half dots, and the dot pitch is 1/120 inch (1/240 <1/180 inch).
By driving the print head at <1/120 = 2x1 / 240) and printing, it is possible to print 1.5 times faster than when driving the print head at a dot pitch of 1/180 inch and printing. . This makes it possible to make the dot configuration finer than that used to drive and print the print head at a dot pitch of 1/180 inch, and also enables high-speed printing with the same print head. 100 when driving the print head at / 180 inch and printing
What was cps becomes 150 cps.

Here, a half dot refers to a dot printed at a position that is half the dot pitch at which the print head is driven. 1/2 above
By driving the printing pins so that printing can be performed at the position, the printing density of the dots, that is, the printing resolution of the printing apparatus is doubled in a pseudo manner, and higher-density printing can be performed. However, the driving speed of the print head is 1/120 inch in the above example of full dots, so
Adjacent full dots printed at an interval of / 120 inches cannot be continuous with half dots located between the full dots (at a position of 1/240 inch). FIG. 4 shows an example of printing using half dots in comparison with an example of printing using full dots. FIG. 4A shows an example of printing composed of only full dots, and FIG. 4B shows an example of printing composed of half dots. In FIG. 4, large black circles indicate full dots, * indicates half dots, and * indicates no dots.

 Next, a description will be given of an increase in printing speed and other matters.

High-speed printing is possible when printing with 1/240 inch spacing as half dots (full dot spacing 1/120 inch) using a print head where the printing pins are arranged at a reference dot pitch of 1/180 inch as follows: .

The print pin has a minimum drive cycle, and cannot be driven earlier than this cycle. This drive cycle is Th, and the dot interval D printed at the drive cycle Th is D = Th × Vc.
Vc is the print head transfer speed in the print head transfer direction, and the print speed of one line is uniquely determined by Vc.

Here Vc _180, and Vc when the D = 1/180 inches D =
Vc when it is 1/120 inch (full dot interval) is Vc ₁₂₀
Then, from D ₁₈₀ = Th × Vc ₁₈₀ D ₁₂₀ = Th × Vc ₁₂₀ D ₁₈₀ = D ₁₂₀ /1.5, Vc ₁₂₀ = Vc ₁₈₀ × 1.5. Therefore, the printing speed when the print head is driven at 1/120 inch is 1.5 times the printing speed when the print head is driven at 1/180 inch. In addition, since 1/120 inch is full dot, it is printed at 1/240 inch pitch including half dot, and it will be printed with higher resolution and faster than 1/180 inch .

Next, when a continuous line of dots parallel to the transfer direction of the print head was printed, the print head was driven at a dot pitch of 1/120 inch and when the print head was driven at 1/180 inch. The printing result will be described.

In a printing device with a resolution of 1/180 inch (common kanji printer), the dot diameter of the print pin is generally 0.2 mm, and the diameter of the print dot is due to ink bleeding during printing. Is 0.26mm in diameter.

Converting 1/180 inch to mm is 0.14mm. Therefore, when continuous dots are printed at 1/180 inch, an overlap of about 0.12 mm occurs between the dots. In addition, 1/120 inch is 0.21 mm, and there is approximately
An overlap of 0.03 mm occurs. Therefore, in any case, there is no case where the dots can be distinguished independently, the print result can be viewed as a line segment, and there is no significant deterioration in print quality. Conversely, you can print at 1/240 inch half dot,
For a pattern having a small number of continuous dots such as a curve, the print quality is improved.

(Effects of the Invention) As described above, according to the print head driving method of the present invention, the basic dot pitch Pv is a natural number multiple or 1/2 thereof.
In a dot matrix printing apparatus equipped with a print head having a configuration widely used in the past, in which printing elements are arranged in the direction of movement of the print head at intervals of a natural number multiple of Pv / 2 <X <Pv Are simultaneously driven at a position which is a natural number multiple of the interval X having the following.

Therefore, it is possible to reduce the power required to solve the problem of magnetic interference and obtain a predetermined driving force while using the conventional general print head as it is, and to reduce the number of printing elements driven simultaneously. By reducing the power consumption at a time, the power consumption required at a time can be reduced, and the power consumption can be evenly distributed over the entire printing period.
There is an effect that noise during printing can be reduced.

According to the print head driving method of the second aspect, in addition to the above-described effects, dots continuous in the transport direction of the print head are not printed at the basic drive pitch X interval. Since the print head is driven so as to print at twice the interval, the relationship of [X <Pv <2X <2Pv] is satisfied, so that printing can be performed at approximately 1.5 times faster than when printing at the conventional interval Pv. In addition, printing can be performed at the interval X in relation to the dot adjacent in the transport direction of the print head and the vertical direction. Therefore, there is an effect that high-speed printing can be achieved with higher resolution than the conventional one.

[Brief description of the drawings]

FIG. 1 is a print pin drive timing diagram when an embodiment of the method of the present invention is applied. FIG. 2 is a layout diagram of print pins in a print head. FIG. 3 is a print pin drive timing chart according to the conventional method. FIG. 4A is a diagram illustrating an example of a character printed with only full dots, and FIG. 4B is a diagram illustrating an example of a character printed with a half dot. 1 to 24 printing pins.

Continuation of the front page (56) References JP-A-1-157864 (JP, A) JP-A-63-281861 (JP, A) JP-A-63-252751 (JP, A) JP-A-63-109064 (JP, A) , A) JP-A-62-23763 (JP, A) JP-A-62-154836 (JP, U)

Claims (3)

(57) [Claims] A print head moving direction at an interval of a natural number multiple of a basic dot pitch Pv, which is a dot pitch in a direction perpendicular to the print head moving direction, or at an interval of a natural number multiple of 1/2 of the Pv. A printhead driving method in a dot matrix printing apparatus equipped with a printhead having a configuration in which a print element is disposed, wherein an interval X having a relationship of Pv / 2 <X <Pv is defined as a basic drive pitch in a printhead moving direction. And a print head driving method. 2. The printing head is driven so that dots continuous in the transfer direction of the printing head are not printed at the basic driving pitch X interval but at twice the basic driving pitch X interval. 2. The print head driving method according to claim 1, wherein: 3. The printhead driving method according to claim 1, wherein a printhead formed so that a locus formed by connecting the arrayed print elements is substantially rhombic in a plan view.