JPH0339269A - Printing control method in serial printer - Google Patents

Abstract

PURPOSE:To overlap conduction signals to a head having N trains of printing elements for a period of 2N times of timing by a method wherein 2N pieces of conduction signal generation means for generating a conduction signal for driving the printing elements in synchronism with a pulse signal divided by a dividing means are respectively provided on 2N pieces of signal conductors. CONSTITUTION:After hour 12-bit registers are cleared, one piece of printing pattern generation request signal is imparted to pattern generation means 6, 7 prior to a printing timing pulse signal. In this manner, the means 6, 7 respectively output a 6-bit pattern for one printing timing for a right-train head and a left-train head. A printing timing pulse signal is imparted to a dividing means 1, and one-shot circuit 2 - 5 generate pulses having a width meeting the conduction specification of printing elements. On the rising of the generated conduction signal, input data to a 12-bit shift register 8 is latched and outputted therefrom, thereafter being enabled by an AND means 12 only for a conduction period. The output of the means 12 is inputted per bit to OR means 16 - 22 each consisting of twelve circuits.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to print control for a serial dot matrix printer in which printing speed is improved by arranging a plurality of print element rows in parallel.

(Prior Art) The printing speed of a serial printer is limited to the maximum driving frequency of the printing element. However, with the increase in printing speed,
Further raising this drive frequency is becoming increasingly difficult.

Therefore, a method has been devised in which the apparent drive frequency is improved by assigning a plurality of printing elements to print dots in the horizontal direction, even though the response characteristics of the individual printing elements remain the same.

These methods are realized by arranging a plurality of print element rows on a print head and distributing print data to the print elements on each print element row by some means. In particular, the idea is centered on two rows of printing element rows as shown in FIG.

An example of using the half-dot pattern, which is the most commonly used printing pattern, in a printer using this two-row head J is to give the printing pattern and timing as shown in Figure 1. .

In the figure, since the pattern is a half-dot structure, it is impossible for dots to exist at consecutive timings 100.

Furthermore, in order to effectively use the two printing lines, black circles 10
The dots represented by 1 and white circles 102 are respectively handled by different printing elements. Therefore, the backprinting element is not driven more than once in four timings.

In other words, the printing element can be driven at a frequency such that four timings correspond to one driving cycle of one printing element, and a speed twice as high as that of a single-row head can be obtained. At this time, each printing element may start energizing even from the four "phases" with four timings as one cycle.
Three printing timings for other printing elements are required during one shortest drive cycle of a certain printing element.

Now, since the 4 timings correspond to the - drive cycle of one printing element, as shown in Figure 2, it is possible that the energization No. 43 1, 2, and 3 generated at a certain timing overlaps with the following three timings. gender must be taken into consideration.

When the energization signal width becomes narrow due to the limitation of printing timing,
This is because the density of dots left on the medium by the printing element is limited to a low density. In particular, the PI multi-column head can provide print timing several times faster than a single-column head, depending on the number of columns, and the printer itself is designed to achieve high speed, so it basically uses a high frequency This problem is important because it is common to try to drive it with

More generally, the energization signal for a head with N rows of printing elements has one cycle of 2N timings, and a maximum of 2N
They must occur overlapping times. At the same time, as shown in FIG. 2, even during the energization period of one printing element, other printing elements must be able to freely start and end energization.

This cannot be achieved by simply inputting the print timing into one energization signal generating means and using the output as the energization signal for each printing element.

As a conventional technology that deals with a similar problem, there is a published patent "Sho 61-52792";
This method is designed to cause the energization signal of one printing element to vary only between two timings, and cannot be applied to the above-mentioned problem.

(Problems to be Solved by the Invention) The present invention is intended to solve the above-mentioned problems,
The purpose is to apply an energizing signal to a head having N rows of printing elements for 2N timings and to freely change the energizing signal to each printing element.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides means for distributing one pulse signal, which gives the drive timing of a printing element, to 2N signal lines in a fixed order; 2N energizing signal generating means provided on each signal line of the book and generating an energizing signal for driving a printing element in synchronization with the distributed pulse signals; and printing data bits for the printing element on the print head. is used as a data input, the 2N pulse signals or the 2N energization signals are used as a clock, and a latch means realizes all the combinations of the data input and the clock; Means for calculating an AND with the energization signal, and OR means for synthesizing 2N outputs of the AND means for each data bit for each printing element were provided to provide 2N systems of energization signal generating means.

(Function) By providing a 2N system of energization signal generation means, the energization can be freely extended to the length of one drive cycle of one printing element without being affected by timing pulses generated during energization. becomes possible.

(Example) Embodiments of the present invention will be described based on the drawings.

In this embodiment, a printing element row 30 having six printing elements 302 such as wire nozzles in one row as shown in FIG.
A printer using a head 300 in which two rows of 1 are arranged will be described.

FIG. 4 is a configuration diagram of this embodiment. In the same figure, 1
is means for distributing input print timing pulse signals into 2 to 5 in a fixed order. Reference numerals 2 to 5 designate one-shot circuits that output an f4 signal through the printing element using the distributed printing timing pulse signal as a trigger. Reference numerals 6 and 7 are means for supplying character patterns for each row of print heads necessary at each print timing as 6-bit data.

Reference numerals 8 to 11 are registers having a 12-bit configuration in which the 12-bit character pattern is used as data input, and the energization signals from one-shots 2 to 5 are used as clocks. Reference numerals 12 to 15 designate AND blocks each comprised of 12 two-manpower AND circuits each having the outputs of the registers 8 to 11 as one input and the energization signal as the other input. 16 to 22 (17 to 21 are omitted in the figure) is a four-person logic system that collects four outputs for each bit number from bits O to 11 of the AND block of the 41, calculates the logical sum, and outputs the result. It is a sum circuit. As for the output of each OR circuit, bits 0 to 5 are for the right head column, and bits 6 to 11 are for the left head column.

FIG. 5 shows a circuit example of means 1 for distributing print timing pulse signals. Four gates 402 are sequentially opened by the output of a quaternary counter 400 using the print timing pulse signal 401 as a clock, and the destination of the print timing pulse signal itself is switched in order.

In the circuit configured as described above, after clearing the four 12-bit registers, one print pattern generation request signal is applied to 6 and 7 in advance of the print timing pulse signal. In response to this, outputs 6 and 7 each output a 6-bit pattern for one print timing for the right row head and the left row head. This 12-bit print pattern data is given as data input to 2-bit registers 8 to 11.

Next, a print timing pulse signal is given to 1 and becomes a 2 trigger pulse. 2 generates a pulse of radiation according to the energization specifications of the printing element.

The input data of the 12-bit register 8 is latched and output by the rising edge (leading edge) of the generated energization signal.

The register output is enabled only during the energization period by the AND means 12 provided at the output. The outputs of the other three registers 9 to 11 range from 1 to 1, which is disable and pull.
Does not affect 8 and 12. 12 output is 1 per bit
It is input to two logical sum means 16-22.

Taking the OR means 16 for bit O of the print pattern data for the right print element row as an example, as described in the "Prior Art" section, this first print data is valid (printed).
If so, 13 at least in the next three printing timings.
The pattern generating means 6 functions so that the signal 1 is not applied from 14 and 15. Since the energization signal generating means 2 also stops outputting by the fourth printing timing, the energization signals sequentially inputted from the AND means 12 to 15 in the OR means 16 overlap even partially. Never. Therefore, the OR result output from 16 is also the same as the energization signal width output by the energization signal generating means 2, and the pulse width will not become abnormally long.

FIG. 6 shows a timing chart of the states of each part of the circuit of FIG. 4. F is the LSB of the pattern for the right head row, that is, the pattern data of bit O of the 12 bits. As can be seen in Fig. 6, if the condition that the dot data given by F is 1 (within 1i) every 4 printing timings is observed, the energization signals will not overlap at the final output O. Since the implementation has already been devised (e.g., published patent "Sho 62-22792J"), we will not specifically discuss the method etc. here.

In Figure 6, depending on the timing of B and G, there is a possibility that a "whisker" as shown in A may occur, but in order to prevent this, it is necessary to add a delay to the energization width input B to the AND block. good.

In general, this amount of delay may be several tens of nanoseconds or less, which is less than a fraction of the print element drive cycle (several kilohertz) of a serial printer, so the effect on print alignment can be ignored.

In this embodiment, the N signal generating means 2 to 5 in FIG. 4 only output a constant pulse width.
Instead, the same effect can be obtained without changing any other parts by using means that changes the intensity of the energization signal in real time according to various parameters such as head drive voltage and temperature.

Further, in this embodiment, the energization signal itself is used as the clock for the 12-bit registers 8 to 1, but the same result can be obtained even if the input trigger signal of the energization signal generating means 2 is used. In this way, it is also possible to use signals 2 to 5 to generate more complicated energization signals such as those for constant current chopper control.

In theory, by simply changing the number of constituent elements, it is possible to accommodate a print head with more print elements in the print element row or a print head with three or more print element rows.

(Effects of the Invention) As described above, according to the present invention, it is possible to set the energization width of each printing element of a multi-row head to be as long as possible without being limited by the speed of printing timing. Furthermore, since it becomes possible for the energization signals of each printing element to overlap, it becomes possible to realize a printer capable of high-speed printing.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of printing patterns and printing timing. FIG. 2 is a diagram showing an example of the relationship between print timing and energization signals. FIG. 3 is a diagram showing an example of printing element arrangement. FIG. 4 is a configuration diagram of an embodiment of the present invention. FIG. 5 is a diagram showing an example of a circuit for determining the printing timing pulse distribution. FIG. 6 is a diagram showing voltage waveforms at various parts. that's all

Claims (1)

[Scope of Claims] When N is an integer of 2 or more, a serial dot matrix equipped with a print head in which N rows of printing elements are arranged in parallel, and having means for sending necessary print data bits to each printing element. In the printer, means for distributing one pulse signal that gives drive timing of a printing element to 2N signal lines in a fixed order, and a means provided for each of the 2N signal lines and synchronized with the distributed pulse signal 2N energizing signal generating means for generating energizing signals for driving the printing elements by using the 2N pulse signals or the 2N energizing signals, the data input being print data bits for the printing elements on the print head; a latch means that uses a signal as a clock and realizes all combinations of data input and clock; a means for logically multiplying the output of the latch means and the 2N energization signals; and an output of the logical product means. A method for controlling printing in a serial printer, comprising: logical sum means for composing 2N pieces of each data bit for each printing element;