JPH0499662A - Dot printer - Google Patents

Abstract

PURPOSE:To momentarily count the number of dots without counting by a software by counting dots for specifying a length of one word, and latching the sum obtained by adding previously counted values. CONSTITUTION:If printing data of a length of each one word of printing data from a drive controller 10 are written in number-of-dots counting means 30, a count converter 31 momentarily counts the number of '1' of the data, converts it to a binary expression, and outputs it to an adder 33. The adder 33 adds this time counted value and the previously counted value, and outputs the sum from terminals AQ0-AQ7 to a latch circuit 35. The circuit 35 latches it as an accumulated counted value based on a write signal WR, and feeds it as a previously counted value to the adder 33 from terminals Q0-Q4.

Description

[Detailed description of the invention] [Industrial application field] [Conventional technology] FIG. 4 shows the conventional configuration of a dot printer.

In the figure, the dot printer consists of a drive control section 10 and an engine section 20. The drive control unit 10 uses the bus 14 to
It consists of a CPU II connected to the computer, a ROM 12 that stores a drive control program, etc., and a RAM 13 that stores print data given as dot data, and the print data is transferred from a host computer (not shown) or the like. On the other hand, the engine section 20 includes a print head 21 (driver 2
2) Consists of carrier motor 23 (driver 24), paper feed motor 25 (driver 26), and the like.

Here, characters, figures, etc. are printed as a group of dots,
The number of dots of the print head 21 is limited to, for example, 18.24 dots due to space considerations and electrical/thermal capacity, and the number of dots that can be printed at one time is also limited. In other words, the number of dots that can be driven per unit time is limited within a certain value. Otherwise, it is impossible to drive the number of dots corresponding to the print data of a certain figure or the like at once and print them all at once.

That is, printing is performed while counting the number of print data (dot data) and limiting the number of driven dots per unit time within a certain value.

Specifically, as shown in FIG. 5, the dot data stored in the print data area (Buffer) of the RAM 13 is read out, the number of dots is counted, and the total memory area (Ml
), and if the value exceeds the number of dots per unit time (- constant value) stored in the ROM 12, the counting procedure is repeated again. As a result, the dot data is counted twice,
The printing process is executed in three steps.

In this way, the dot data is counted by the CPU 11.
, ROMI 2. This is performed by software processing in cooperation with RAMI 3.

While the expansion of the area is remarkable, the number of dots driven per unit time can be greatly increased by the above-mentioned electrical method.

This is not possible due to thermal problems. Furthermore, the functions required of printers are becoming increasingly complex, and the software processing burden is also increasing.

Therefore, if the counting of dots is processed by software, the software processing time of the entire printer becomes larger and larger, and as a result, the printing speed decreases, making it impossible to meet the demand for high-speed printing.

On the other hand, although it is conceivable to increase the capacity and speed of the drive control section 10, it is extremely difficult to realize this in terms of cost and space.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dot printer that can significantly shorten the software processing time required to count the number of dots and achieve high-speed printing.

[Problem to be solved by the invention] By the way, the present invention uses the combination printing of characters and figures, etc. [Means for solving the problem] The present invention is capable of printing one word length with one write pulse from the drive control section of the printer. One of the above objects is achieved by configuring the device to instantaneously count the number of dots using hardware.

That is, the present invention counts the number of "1"s corresponding to the dots to be printed out of the n bits that define the length of one word written from the drive control section of the printer, and converts the count value into m bits. A counting/conversion circuit that converts into binary representation, and a previous count value and m that are expressed as l-bit binary representation.
An adder that outputs the sum of the current count value, which is expressed as a binary representation of bits, as a binary representation of l bits, and l that latches the output of this adder as a cumulative count value.
It is characterized by providing a bit latch circuit and a dot number counting circuit.

[Function] In the present invention, one part of the print data is sent from the drive control section of the printer.
Write the word length to the dot number counting circuit.

Then, the counting/converting circuit counts the number of "1"s corresponding to the dots to be printed out of the n bits, and converts this current count value into an m-bit binary representation and outputs it. On the other hand, the adder adds the m-bit current count value and the n-bit binary-represented previous count value, and outputs the sum as a j-bit/y-bit binary representation. This sum is launched into a latch circuit as a cumulative count value. When counting the next word length, this cumulative count value or the previous count value is input to the adder.

Therefore, by reading the latched value into the latch circuit, the number of dots can be instantaneously counted by performing counting processing using software in the drive control section. Since it is executed by hardware, the software processing time required for dot counting in a drive control section consisting of a CPU or the like can be significantly shortened, and printing speed can be increased.

[Example 1 Hereinafter, one embodiment of the present invention will be briefly described with reference to the drawings.

As shown in FIG. 1, this printer has the same basic configuration as the conventional configuration (see FIG. 4) consisting of a drive control section 10 and an engine section 20, and is equipped with a dot number counting circuit 30 to count the number of printed dots. The hardware is configured to allow instant counting.

Therefore, the basic configurations (10, 20) will be given the same reference numerals and the explanation thereof will be omitted. Note that a program shown in FIG. 2 is stored in the ROM of the drive control section 10.

Here, the dot number counting circuit 30 includes a counting/conversion port #131, an adder 33, and a latch circuit F#i35 as shown in FIG.
It is composed of.

Here, the counting/conversion port #I31 counts the number of "1"s corresponding to the dots to be printed out of the n-bit data of one word length of the print data written from the drive control section 10. , and is means for converting the force run t value into an m-bit binary representation and outputting it. In this embodiment, "n" is "8" bits consisting of DATAO-7, and "m" is "4" bits consisting of bito-bit3.

Therefore, the counting/conversion port path 31 is formed of four full adders FAI to FA4 and three half adders HAI to HAB connected as shown in FIG. ) is converted into binary code and output.

This count value is the current cant value.

That is, "1" out of the n-bit data of one word length is added instantly, and the sum is output to the adder 33.

This adder 33 then combines the p (8 in this example) bit binary-represented previous count value with m(4)
There is a means for adding the current count value expressed in binary bits and outputting the sum as 1 (8) bit binary expression from terminals AQO to AQ7.
It is made up of two Kaadars. That is, the counting/conversion port #r31 adds the current count value and the previous count value to obtain the cumulative count value.

Note that the previous count value is the content stored in the latch circuit 1i4G35, which will be described later. Also, the upper 4 bits of the adder 33 are 0''
Fixed.

This latch circuit 35 latches the cumulative count value.
(8) Formed from a bit register, input terminal D
It has output terminals QO to Q7. Furthermore, a write pulse WR from the drive control section 10 is applied to the trigger input terminal T. Note that a clear pulse CL for establishing an initial state is input to the terminal CLK.

Note that the bit numbers n, m, and j may be appropriately selected and configured based on the limit value of the number of dots that can be driven per unit time.

Next, the effect will be explained.

The drive control unit 10 outputs print data DATAO to 7 for each word of print data at the timing shown in FIG.
(00000001)8 = 80H(1000000
0),,,03H(00000011)@,07H(0
0000111) Count the number of dots in the order of e, #r30
(Step 10 in Figure 2). It is assumed that the latch circuit g@35 is cleared by the signal CL.

First, the counting/converting circuit 31 instantaneously counts the number of "1"s in the print data OIH, converts the count value "1" into a binary representation of 4 bits bit to bit3, and outputs it to the adder 33. do.

Then, the adder 33 adds the current count value "1" and the #i7 count value (at this stage, since the latch circuit 35 is cleared, it is rQ), and outputs the sum to the terminal AQO. - Output to the latch circuit 35 from AQ7.

Here, the latch circuit 35 latches the total count value based on the write signal WR. This cumulative count value is fed from the terminals QO to Q7 to the adder 33 as the previous count value.

In this way, the next print data 80H, 03H, 07
When H is sequentially written to the counting/conversion port #I31, each “1”
”, as shown in Figure 3, 'IJ, '2J
, '3J Tona') 4 hits (bitO~b
The binary representation of it31 is input to the adder Xer 33.

At this time, the adder 33 is fed with the previous count values rl'', 'IJ, and '2J from the latch circuit 35.

Therefore, the sum of the adder 33 is "2"'4J,r7'
It increases as follows. This sum, that is, the print data DATAO
The cumulative count of bit "1" among ~7 is latched 1 for each write signal WR! ! 35.

When the counting for one line of print data is completed (step 12), the drive control section 10 reads the number Qout of dots to be printed expressed in binary form at the terminals QO to Q7 of the latch circuit 35 (step 14).

Here, the number of dots to be printed out of the print data can be instantaneously counted by the hardware (30) based on software processing of the drive control section 10.

According to this embodiment, the counting/converting circuit 31, the adder 33, and the latch circuit F! A dot number counting circuit 30 consisting of @35 is provided, and the count of dots is separated from the software processing of the drive control unit 10, and the count is instantaneously performed by hardware.
It is possible to significantly reduce software processing time and achieve faster printing.

In addition, the counting/conversion circuit 31 outputs “1” of n bits.
The count value is output as an m-bit binary representation, and the latch circuit F#I 35 of the adder 33.1 pit is configured to add binary representation data, etc., so it is simple. This configuration allows large count values to be latched at low cost, and can also be applied directly to large-capacity, high-resolution dot printers.

Furthermore, count the number of dots F! Since @30 is configured to independently count the written print data, it can perform counting operations without affecting the processing timing of the drive control section 10 and without requiring a system clock.

[Effects of the Invention] According to the present invention, a dot number counting circuit consisting of a counting/conversion circuit, an adder, and a latch circuit is provided, and the dot counting is performed independently in terms of hardware. The software processing time of the control unit can be significantly shortened, and the printing speed can be increased, which is an excellent effect with wide applicability.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a flowchart for explaining the operation, FIG. 3 is a timing chart for explaining the operation, and FIG. 4 is a circuit of a conventional printer. 5 and 5 are flowcharts for explaining the operation of counting the number of dots by conventional software processing. DESCRIPTION OF SYMBOLS 10... Drive control part, 11... CPU, 12... ROM, 13... RAM, 20...-engine part, 21... Print head, 30... Dot number counting circuit, 31 ... Counting/conversion circuit, 33... Adder, 35... Latch circuit.

Claims (1)

[Claims] (1) Count the number of "1"s that correspond to the dots to be printed out of the n bits that define the length of one word written from the printer's drive control unit, and convert the count value into m-bit binary representation. The counting/conversion circuit to convert, the previous count value expressed as l-bit binary representation, and m
An adder that outputs the sum of the current count value, which is a binary representation of bits, as an l-bit binary representation, and an l that latches the output of this adder as a cumulative count value.
A dot printer characterized by having a bit latch circuit and a dot number counting circuit consisting of a bit latch circuit and a dot number counting circuit.