JPS61192560A - Dot control system - Google Patents

Abstract

PURPOSE:To enable not only the superposition of a reference dot and a half dot but also sharp printing by performing enlargement and contraction in arbitrary magnification, by making the output timing half dot variable by two lines of printing heads arranged in a zigzag pattern CONSTITUTION:A mode setting flip-flop 4 for setting the output timing of a half dot line 22 to timing 1 coming to the output timing of a reference dot or timing 2 delayed by predetermined time from the timing 1 is provided. The output timing of the half dot 22 can be changed if necessary. When a contracted character is printed by setting a dot pitch smaller than a basic dot pitch by using two lines of printing heads arranged in a zigzag pattern, if either one of dot lines is determined to the reference dot line, a printing position is shifted from an objective position only with respect to the half dot 22 and, therefore, the driving timing of the half dot 22 can be made arbitrarily changeable to make it possible to perform enlargement and contraction in arbitrary magnification.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a dot control system, and in particular to a dot control method for a serial dot matrix type printer using print heads arranged in a staggered manner at a distance that is a non-integer multiple of the dot pitch. This concerns the control method.

[Background of the invention]

In a serial dot matrix printer that uses print heads that are arranged in two staggered rows at a distance that is a non-integer multiple of the dot pitch, half-dot rows are arranged horizontally in relation to the basic dot row, as shown in Figure 2. and vertical columns are placed at shifted positions. By using a staggered arrangement, it is possible to print with closely spaced dots or to print with some of the adjacent dots overlapped, thereby improving the printing quality. One character with a print head like this.

Conventionally, as a method of enlarging or reducing a figure,
There are those described in JP-A No. 166785, JP-A-58-169688, and the like. In the former.

The control circuit is simplified by converting and storing the character generator (CC) itself in advance so that the zigzag conversion logic is not required.
Normally, editing is performed using hardware or a microprogram (staggered conversion logic) so that leading and trailing dots can be superimposed, but in the former case, this is
G is first converted and stored. In the latter case, the contents of the character and graphic data registers are enlarged or reduced in size and printed by changing the clock ratio when transferring them to the pattern buffer memory. That is, when enlarging the image twice, the same content is transferred twice to the pattern buffer memory in both the vertical and horizontal directions. but,
In the former case, the capacity of the CG memory becomes large, and when converting dots, it is necessary to overlay and edit adjacent characters. Furthermore, in the latter case, there is a problem that the magnification of enlargement or reduction is limited to an integer multiple or a fraction of an integer, and cannot be changed to an arbitrary magnification. - In the staggered arrangement, as shown in Figure 2, the distance a between the reference dots 21 is
The half dot rows 22 are arranged at positions 7.5 times apart from each other, and conventionally, their drive timings are fixed. That is, in FIG. 2, among the outputs of the temporary storage circuits for both the reference dot 21 and the half dot 22,
The data corresponding to the reference dot 21 has a fixed timing [
1], while the data corresponding to the half dot 22 is output at a fixed timing [2]. In FIG. 2, when printing is performed with the dot pitch in the scanning direction set to a, if the reference dots 21 and half dots 22 are printed at the same timing.

The reference dot 21 and the half dot 22 cannot be superimposed on the same line because they are shifted by 0.5 pitch.
Therefore, in the head with the dot arrangement shown in FIG. 2, the dots are controlled at different fixed timings, and as shown in FIG. 4, when the dot drive period is T, the half dot 22 is T/2 output with a different timing.

In this case, when the print head is scanned to the right and the timing of the half dot 22 is delayed by T/2, the half dot 22 is printed at position 8 in FIG. T the timing
When delayed by /2, half dot 22 will be printed at position 7. Therefore, when scanning in the right direction, the reference dot 21 is overlapped with the reference dot 21 printed 8T later, and when scanning in the left direction, it is overlapped with the reference dot 21 printed 7T earlier. In Figure 4.

Timing [1] and timing [2] of controlling the reference dot and the eighth dot for t time by shifting them by T/2.
pulse, a write timing pulse for constantly updating the data in the memory circuit that temporarily stores the dot data to be output, and a write timing pulse to write the data (n-IL n,
(n+1).

and the data (ntL n, (n+1)) of the reference dot row and herb dot row output from the dot storage circuit are shown. In this way, the scanning speed of the print head and the number of times the print element is driven per unit time If the ratio is constant and the dot pitch in the scanning direction of the print head is constant, the conventional enlargement and reduction functions are sufficient.However, it is possible to change the ratio of the number of times the print head and print element are driven per unit time. hand.

When making the dot pitch in the scanning direction of the print head variable, conventional enlargement and reduction functions cannot provide the desired effect. That is, as shown in FIG.

When attempting to print by doubling the ratio of the number of times the print element is driven per unit time to the scanning speed of the print head and setting the dot pitch to a/2, the herb dot 22 is moved from the reference dot 21 to an integer multiple of the dot pitch (the third In the diagram,
15 times).

If the herb dot 22 is output at a fixed timing and shifted by T/2 from the reference dot 21 as shown in Fig. 4, the overlapping will not occur, unlike in the case shown in Fig. 2. . That is, in this case, the reference dots 21 and the half dots 22 must be made to have the same timing to be superimposed.The same holds true even when the dot pitch is set to 5a/6. 576 (elite), which is often needed as a reduced pitch, using a print head with a spacing of 7.5
The same thing applies when printing 315 (condensed), 1/2 (half-width), etc., and if a print head in which the interval between the reference dot 2I and the half dot 22 is a non-integer multiple of the basic dot pitch is used, both There was a problem in that the dots could not be superimposed, and as a result, the printed state was disturbed.

[Object of the Invention] The object of the present invention is to solve such conventional problems, to use two rows of staggered print heads, to make it possible to superimpose reference dots and half dots, and to enlarge the dots at any magnification. An object of the present invention is to provide a dot control method that can print clearly by reducing the size.

[Summary of the invention]

In order to achieve the above object, the dot control method of the present invention includes a storage means for temporarily storing only the half dot data out of the reference dot data and half dot data, and a first timing for outputting the reference dot data. a second timer delayed by a predetermined time from the first timing;
a timer that generates the timing of
The present invention is characterized in that it includes means for determining which of the timings is used to output the half-dot data, and that the timing determining means makes the output timing of the half-dot data variable.

[Embodiments of the invention]

EMBODIMENT OF THE INVENTION Below, one embodiment of the present invention will be described in detail with reference to the drawings.

The principle of the present invention is that when printing reduced characters with a dot pitch smaller than the basic dot pitch using a print head arranged as shown in Figure 2, if one of the dot rows is set as the reference dot row, the printing position Since it is only the half dots that deviate from their target positions, the drive timing of the half dots can be arbitrarily varied to enable enlargement or reduction at an arbitrary magnification.

FIG. 1 is a block diagram of a dot control circuit showing an embodiment of the present invention.

This dot control circuit includes a dot storage circuit 1 for temporarily storing dot data of both reference dots and herb dots, and a half-dot storage circuit 1 for temporarily storing only dot data corresponding to half dots out of the output of this dot storage circuit 1. A timer 2 generates a pulse at timing (1) which is the output timing of the circuit 8 and the reference dot, and a timer 2 generates a pulse at timing [1] triggered by the occurrence of the above timing [1].
], a timer 3 generates a pulse at timing [2] that is delayed by a predetermined time from [ ], and a mode setting flip-flop ( (hereinafter referred to as F/F) 4, the pulse at timing [1] is the first human power, the pulse at timing [2] is the second human power, F/F
The output of F4 is used as the third manual power, and when the output of F/F4 is O, a pulse at timing [2] is output, and F/F4
When the output of 1 is 1, the selector 9 outputs the pulse at timing [1], the inverter 5 inputs the pulse at timing (1), and the output of the inverter 5 is controlled by the first human power,
The AND gate 6 uses the pulse at timing (2) as the second human power, and the output of this AND gate 6 is the first human power, F/F
Among the outputs of the OR gate 7 which uses the output of 4 as the second human power, and the output of the dot memory circuit 1, only the dot data corresponding to the reference dot is output at the timing (the reference dot output circuit 10 which outputs with the pulse of 13 and the herb dot memory circuit 8). and a half-dot output circuit 11 that outputs the output (half-dot data) of the output signal (half-dot data) using the output pulse of the selector 9 (pulse at timing [1] or timing (2)).

The reference dot output circuit 10 includes a NOR gate 12 whose first input is the output of the dot memory circuit 1, and whose second input is the pulse at timing (1), and whose input is clamped to 0, and whose input is clamped to 0.
Buffer 1 whose enable input is the output of R gate 12
It consists of 3.

Since the output of the buffer 13 is tri-state, the dot data is O and the pulse at timing (1) is O.
Only during this period, the output is in the Z (high impedance) state, and is 0 otherwise. These circuits are provided as many as the number of reference dots.

The half-dot output circuit 11 also has a reference dot output port 10.
However, the output of the herb dot memory circuit 8 is input instead of the output of the dot memory circuit 1, and the output of the selector 9 is input instead of the pulse at timing [1]. The latch timing of half-dot storage circuit 8 is determined by the output of OR gate 7. Although not shown, a control circuit using a microprocessor is provided at the front stage of FIG. Data is written to F/F4 and timer 2 is triggered.

Further, a drive circuit for the print head is connected to the latter part of FIG. The reason why the half-dot memory circuit 8 is provided independently in FIG. 1 is as follows.

This is because when printing at high speed, it is necessary to rewrite the dot data in the dot storage circuit 1 before the output of half dots is completed.

Figures 5 and 6 are the operation time charts of Figure 1.
FIG. 5 is a control timing chart when the output of F/F4 is set to 0 in advance, and FIG. 6 is a control timing chart when it is set to 1.

First, in Fig. 5, the timing (1
3 and timing [2] pulse, output of selector 9, latch timing of half-dot storage circuit 8, write pulse of dot data, output of dot storage circuit 1, output of half-dot storage circuit 8, output of reference dot output circuit IO, and the output of the herb dot output circuit 11 are shown.

When the timer 2 is triggered by a control circuit (not shown) at the previous stage, a pulse at timing [1] is outputted at a period T. moreover.

T/2 triggered by the falling edge of the pulse at timing [1]
A pulse at timing [2] is output from the timer 3 with a delay of .times. Since the output of F/F4 is set to O,
The selector 9 outputs a pulse at timing [2]. Furthermore, the signals (timing [1] and timing [2]) after passing through the inverter 5 and the AND gate 6 are input to the latch input of the herb dot storage circuit 8. This is the latch timing. Of the outputs of the dot storage circuit 1, half-dot data is held in the half-dot storage circuit 8 at the falling edge of the latch timing signal. Of the outputs of the dot storage circuit 1, the reference dot data is outputted from the reference dot output circuit 10 with a pulse at timing [1].

Further, the half-dot data is outputted from the half-dot output circuit 11 with a pulse at timing [2] after passing through the half-dot storage circuit 8. Incidentally, the dot memory circuit 1 is triggered by the rising edge of timing [1].
It is rewritten every moment by the dot data write signal shown in the figure.

Control timings (1) and (2) in Fig. 5 are used when the interval between the reference dot row and the herb dot row is an integral multiple of the dot pitch, such as when the dot pitch is the basic dot pitch or when the basic dot pitch is 375. applied when the distance is equal to +1/2 of the dot pitch.

That is, the arrangement shown in FIG. 2 is used in the print head.

In FIG. 6, timings [l), (
2) pulse, output of selector 9, latch timing of half-dot storage circuit 8, write pulse of dot data, output of dot storage port jll, half-dot storage circuit 8
．． , the output of the reference dot output circuit 10, and the output of the half dot output circuit 1 are shown.

The difference between the control timing chart in FIG. 6 and the one in FIG. 5 is that since the output of F/F 4 is 1, the half-dot latch timing (output of OR gate 7) is always 1, and the dot storage circuit 1 Among the outputs of , the half dot data is passed through and the output of the half dot storage circuit 8 is cursed, and the output of the selector 9 becomes a pulse at timing (1). As a result, the half dots are output at exactly the same timing as the reference dots.

The control timing in FIG. 6 is such that the dot pitch is, for example, 172. Or, as in the case of 5/6, it is applied when the distance between the reference dot and the half dot is equal to a distance that is an integral multiple of the dot pitch. For example, the third
It is used for heads arranged as shown in the figure. The reason for arranging the half dots with respect to the printing element of the print head as shown in FIG. This is to reduce the peak value of the drive power of the print head by half.

In the case of wire dot impact, the reasons include reducing noise and alleviating magnetic interference between magnetic circuits for driving each wire dot. Here, if control is performed as shown in FIG. 6, that is, control is performed such that the drive timings of the reference dot and half dot are the same,
There is a concern that the above problem may come to light, but the following can be considered. That is,
In the case of a dot pattern with a coarse dot density, such as alphanumeric and kana characters, this is not a problem because the number of times the dots are driven per unit time is small. Also.

When printing dot patterns with a relatively high dot density, such as kanji, if the dot pitch of the high-density pattern is made smaller than the basic dots and reduced printing is performed, the sharpness of a single character will be lost. If such a process is used in combination with the control shown in Figure 6, which involves thinning out the dots so that there are no consecutive dots, the above problem will not occur, and clear reduced kanji characters can be printed. It becomes possible.

The dot pitch of reduced characters is mainly 1/2 (half-width), 315 (condensed), and 5/2 of the basic dot pitch.
6 (elite), all of which can be realized by the control shown in FIGS. 5 and 6. 2.Although it seems that there is little need for reduced characters with dot pitches other than those mentioned above, if there is a need, the output timing of half dots may be determined as follows.

The interval between the reference dot and half dot is n times the basic dot pitch (n is not necessarily an integer), the dot pitch is m times the basic dot pitch (0<m<1), and the dot period is T.
In this case, the half-dot output timing is T・(1-R(for n/) when scanning i in the forward direction to print.
) from the reference dot timing, where R (for n/) is the remainder when n is divided by m (
(number below the decimal point). For example, n==7.5. m
When =415, for n/, =9.375, so R(n/m) is 0.375. Scan the print head to the left/sometimes use T-R (for n/)
It is only necessary to delay the timing of the reference dot by only the timing of the reference dot. this is.

The setting value of timer 3, which determines the output timing of the pulse at timing [2], is changed by the program, and T-(1
-R (for n/)) or TR (for n/) timing can be obtained, and this can be easily realized by using a programmable timer. in this way.

In this embodiment, the output timing of half dots can be changed as necessary using a simple circuit configuration.

In addition, in this embodiment, even if the timing (L) pulse and the timing [2] pulse overlap because of low speed printing, the half dot output timing can be changed in various ways. Not lost.

Furthermore, in this example, as mentioned above, n-7,
If the dot pitch is limited to 1/2.315.5/6.1/1 of the basic dot pitch using a print head of 5, the pulse of timing [2] will always be at timing [1].
] It is sufficient to delay the pulse by T/2 from the pulse of F/F.
Since all you need to do is change the setting of timer 3, even when characters with different dot pitches are mixed on the same line, if you keep the dot period T constant and control the dot pitch by changing the scanning speed of the print head, timer 3 There is no problem even if the set value of
Printing of reduced characters at a variable pitch using staggered rows of print heads can be achieved with simple hardware and processing. That is, it is possible to print reduced characters at various dot pitches smaller than the basic dot pitch by using print heads arranged so that the distance between two rows is an integral multiple or a non-integer multiple of the basic dot pitch. In particular, even in patterns with a high density of dots, such as kanji, by combining dot thinning processing and the control method of the present invention, the same CG can be used to create clear reduced characters (for example, half-width characters, condensed characters, elite characters). )
can be printed.

[Effects of the Invention] As explained above, according to the present invention, by making the output timing of herbal dots variable with the two rows of staggered print heads, printing can be performed even when printing at a dot pitch smaller than the basic dot pitch.

It is possible to overlap the reference dot and half dot,
It can be enlarged or reduced at any magnification and printed clearly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a dot control circuit showing one embodiment of the present invention, FIGS. 2 and 3 are dot arrangement diagrams of a print head, and FIG.
The figure shows the control operation time chart in Figure 2, Figure 5,
FIG. 6 is a control operation time chart of FIG. 1. 1: Dot memory circuit, 2.3: Timer, 4: F/F, 5
: Inverter, 6: AND gate, 7: OR gate, 8
: Half dot storage circuit, 9: Selector, 10: Reference dot output circuit, 11: Half dot output circuit, 12,1
4: NOR gate. 13.15 Dry state buffer Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] (1) In a serial dot matrix printer that uses print heads arranged in a staggered manner in two rows at a distance that is a non-integral multiple of the dot pitch, only the half-dot data out of the reference dot data and half-dot data is used. a timer that generates a first timing for outputting the reference dot data; a timer that generates a second timing that is delayed by a predetermined time from the first timing; 1. A dot control system comprising means for determining which of the timings is used to output half dot data, and the timing determining means makes the output timing of the half dot data variable.