JPH0354064B2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention prints Chinese characters, etc. at high speed by arranging a plurality of printing heads having a plurality of printing elements (for example, wires) in a horizontal straight line facing a printing paper. This invention relates to a power consumption limiting system for a so-called multi-head dot line printer.

(Prior art) Conventionally, in such multi-head dot line printers (hereinafter abbreviated as LP), printing is not performed at a very high printing duty (for example, 30% or less) at a normal business level. Considering that all multiple heads print data with high print duty (100%) at the same time (solid printing), the power supply capacity of the printer must be increased accordingly, and the shape and weight of the power supply are large. Therefore, the cost of the printer equipment is high, and the power distribution capacity in the office where the printer is installed, for example, has to be increased accordingly.

(Purpose of the invention) The present invention was made in view of this point, and aims to optimize (downsize) the power supply device of LP, and eliminates the need for special power distribution work due to the increase in instantaneous maximum power consumption in general offices. It provides low-priced LPs with the following characteristics.

(Structure of the Invention) The present invention includes a plurality of print heads having a plurality of print elements (for example, wires), a plurality of head drivers for driving the plurality of print elements of the print head,
A read (write) line buffer memory that stores at least one line of print data, a write (read) line buffer memory that stores at least one line of print data, and a read/write line buffer memory that stores at least one line of print data. A row buffer memory switching section that performs switching, a parallel-to-serial conversion section that converts parallel print data to serial print data, a counter that counts the number of print data that drives the print element, and multiple print heads on the left and right. Space motor (S.
P motor), a line feed motor (LF motor) that moves the printing paper (line feed), a printing mechanism control unit that controls the plurality of head drivers, SP motor, LF motor, etc., and a microcontroller that controls these. The print data transferred from the host device holding the data to be printed is stored in the write line buffer memory via the microprocessor, and is also sent to the counter via the parallel to serial converter for printing. The number of print data that drives the element is counted, the print duty is determined, and the print duty is stored in a specific location in the writing row buffer memory where print data is not stored. Then, when printing, a specific print head is selected from among multiple print heads depending on the size of this print duty, and one
A line is printed using multiple print heads at once or in several batches. A detailed explanation will be given below based on examples.

(Example) Figure 1 shows an example with four print heads.
A plan view of the printing mechanism section of the LP is shown. 1 is a platen, 2 is a carriage that moves left and right by an SP motor, 3-1, 3-2, 3-3, and 3-4 are print heads fixed to the carriage 2 at regular intervals;
4 is printing paper. If the number of characters printed for one line is 88 characters, there are four print heads 3-1, 3
-2, 3-3, and 3-4, each head prints 22 characters in one printing operation. Second
The figure is a block diagram of an LP showing one embodiment of the present invention. Reference numeral 5 denotes a microprocessor that controls the entire printer, and is composed of, for example, Intel 8085. 6 and 7 are rewritable storage devices that store one line of print data and print duty information, and 8 and 9 are row buffer memories 6, 7 so that the row buffer memories 6, 7 can write/read independently. 7 is a row buffer memory switching unit for selecting the data; 10 is a parallel-to-serial conversion unit for converting parallel data into serial data;
11 is the print head 3-1, 3-2, 3-3, 3-
4 is a counter for counting the number of print data that drives a plurality of printing elements (not shown) that constitute 4; 12 is an SP motor that moves the carriage 2 shown in FIG. LF motor moving (line feed), 14-1, 14-2, 14
-3, 14-4 are the corresponding print heads 3-
a head driver 15 that drives a plurality of printing elements (not shown) constituting 1, 3-2, 3-3, and 3-4;
is a printing mechanism control section that controls the SP motor 12, LF motor 13, head drivers 14-1, 14-2, 14-3, 14-4, etc. FIG. 3 is a diagram explaining the printing operation. An example of the printing operation will be described below with reference to FIG. First, print data is transferred from a host device (not shown) and stored in the writing buffer memory 6 or 7 via the microprocessor 5. Also, the print data is simultaneously converted to serial data by the parallel to serial converter 10 and sent to the counter 1.
Each time data (for example, binary "1") that is given to "1" and drives a plurality of printing elements is input, the count is incremented. When one line of print data is stored in the write line buffer memory 6 or 7 in this way, the value of the counter 11 is read into the microprocessor 5, and the microprocessor 5 sets the solid print as 100% printing duty. The print duty is determined and stored in a specific location in the write line buffer memory 6 or 7 where print data is not stored. When the print data and print duty information for one line are thus stored in the writing line buffer memory 6 or 7, the line buffer memory switching unit 8, 9
As a result, the write line buffer memory 6 or 7 becomes the read line buffer memory 6 or 7, and the printing mechanism control unit 15 selects a predetermined print head 3-1 or 7 according to the print duty information stored in the read line buffer memory 6 or 7. 3-2 or 3
-3 or 3-4 head driver 14-
1 or 14-2 or 14-3 or 14-4 to drive the SP motor 12 and transfer the print data stored in the readout row buffer memory 6 or 7 to the head driver 14-1 or 14-2 or 1.
4-3 or 14-4 to print at once or in several batches. For example, the print duty is 0~
When it is 30%, the carriage 2 in Figure 1 is shown in Figure 3 a.
All print heads 3-1, 3-2, 3-3, 3- at once with forward or backward running.
Head drivers 14-1, 14- corresponding to 4
Select 2, 14-3, 14-4 and print one line. Therefore, at this time, one line is printed in the forward run, and one line is printed in the next backward run. Next, when the print duty is 30 to 60%, the print head 3-
Head driver 14-1 corresponding to 1, 3-2,
Select 14-2, print, and continue printing backwards without line feed (LF) until printing head 3-
Head driver 14-3 corresponding to 3, 3-4,
14-4 is selected and printing is performed to print one line. Therefore, at this time, printing for one line is performed by two runs, a forward run and a backward run, and a line feed is performed. Next, the print duty is 60%.
In the above case, as shown in Fig. 3c, the head driver 14-1 corresponding to the print head 3-1 is selected in the first forward run, and printing is performed without a line feed, and then the print is performed in the first backward run. The head driver 14-2 corresponding to the print head 3-2 is selected and printing is performed, and then, in the second forward run, the head driver 14-3 corresponding to the print head 3-3 is selected and printing is performed without starting a line feed. Then, in the second backward run, the head driver 14-4 corresponding to the print head 3-4 is selected and printing is performed without performing a line feed, thereby printing one line. Therefore, at this time, printing for one line is performed by a total of four runs, two forward runs and two backward runs, and a line feed is performed. Note that the print data from the read line buffer memory 6 or 7 is transferred to the head drivers 14-1, 14-2, 14-.
3 and 14-4, print data and print duty information are stored in the other writing row buffer memory 6 or 7 in the same manner as described above as long as the print data exists in a host device (not shown). In this manner, printing and storage of print data and print duty information in the line buffer memory are performed simultaneously, and the print data is sequentially printed on the print paper.

(Effects of the Invention) As explained in detail above, before printing, the number of print data that drives the print elements constituting the print head is counted to obtain the print duty, and when printing, if the print duty is low, the print data is printed once. By selecting the print heads to increase the number of print heads that are used for one printing when the print duty is high, and by selecting the print heads to reduce the number of print heads that are used for one printing when the print duty is high, any printing can be performed. Even when printing duty print data, the printer automatically selects a predetermined print head and prints one line at a time or in several batches, which limits the maximum amount of power consumed by the printer's print head. Limiting the instantaneous maximum power consumption of the printer and eliminating the need to decide the power supply capacity considering the worst case printing (solid printing with 100% printing duty) allows for miniaturization (optimization) of the power supply device and the installation of LP. There is no need for special power distribution work due to the increase in instantaneous maximum power consumption in general offices, etc., and there is an advantage that the equipment price can be reduced.

[Brief explanation of drawings]

Figure 1 is a plan view of the printing mechanism for Kanji LP having four print heads, Figure 2 is a block diagram showing one configuration of the present invention, and Figure 3 is a time chart explaining the printing operation. be. 1...Platen, 2...Carriage, 3-1,
3-2, 3-3, 3-4...Print head, 5...
Microprocessor, 6, 7... row buffer memory, 8, 9... row buffer memory switching section, 10...
...Parallel/serial converter, 11...Counter, 12...SP motor, 13...LF motor,
14-1, 14-2, 14-3, 14-4...head driver, 15...printing mechanism control section.

Claims (1)

[Claims] 1 A plurality of print heads consisting of a plurality of printing elements and a carriage are mounted on which the plurality of print heads are mounted at regular intervals, and when printing, the plurality of print heads and the carriage are moved left and right with respect to the printing paper. In a dot line printer, which has a space motor that moves the printing paper and a line feed motor that performs line feed by moving the printing paper, each print head specifies the area to print, and prints one line with multiple print heads. The printer is equipped with means for counting print data that drives the printer to obtain a print duty, and means for selecting a predetermined print head from among a plurality of print heads based on the print duty, and selecting a print head at once depending on the size of the print duty. A power consumption limiting method for a multi-head dot line printer, which is characterized by controlling the number of dots and printing one line by driving a space motor at once or in several batches.