JP2881954B2 - Printing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Industrial application field) The present invention relates to a dot matrix type printing apparatus, and more specifically, a part of continuous dots in a basic dot pattern such as a character or a figure to be printed is deleted. above,
The present invention relates to a printing device that prints the remaining dots at appropriate printing timing.

(Prior Art) Conventionally, in a print head used in a dot matrix type printing apparatus, the printing speed of continuous dots is determined by the response frequency thereof. Therefore, the printing speed of the printing apparatus is determined by the printing speed of continuous dots. Was. Therefore, when increasing the printing speed of the printing apparatus, it is necessary to increase the response frequency of the printing head by improving the mechanical mechanism for operating the printing wire provided in the printing head.

(Problems to be Solved by the Invention) However, in order to improve a mechanical mechanism for operating a print wire provided in a print head and develop a print head having a high response frequency, there are technical problems and cost problems. Has to be solved.

Therefore, in the present invention, instead of realizing high-speed printing by improving the mechanical mechanism of the print head, high-speed printing is realized by extracting continuous dots of the basic dot pattern and then deleting some of the continuous dots. Is a technical problem to be solved.

(Means for Solving the Problems) The technical means for solving the above problems is to provide a print head having at least one row of a plurality of dot print elements each capable of printing one dot on a print medium, and printing the print head. Moving means for relatively moving a head and a print medium along a printing direction substantially intersecting the row of dot print elements, driving means for driving the print head, and dots indicating presence / absence of printing and a print timing position A printing apparatus comprising: a storage unit in which a pattern is stored, and a print control unit that prints on the print medium by controlling the moving unit and the driving unit according to a dot pattern stored in the storage unit. Continuous dot extraction for retrieving the dot pattern for each series of dots that can be printed by one dot print element and extracting a predetermined number of N consecutive dots Means, and a new dot is created based on the N consecutive dots extracted by the continuous dot extracting means.
Dot data changing means arranged at a print timing position between dots other than the first dot of the continuous dots and changing the dots other than the first dot of the N consecutive dots based on the new dot. .

(Operation) According to the printing apparatus having the above-described configuration, when the continuous dot extracting means retrieves the basic dot pattern for each dot row and extracts a predetermined number of N consecutive dots, the dot data deleting means sets By deleting the print data of at least one of the dots, the print speed can be increased without significantly deteriorating the print quality.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 6 show a first embodiment of the present invention.

In FIG. 1, reference numeral 20 denotes a printer control CPU, 21 denotes a ROM in which a program for causing the printer control CPU to execute an operation according to a flowchart described later, a pattern such as a character font, and the like are written, and 22 denotes a reception buffer 23 and an image. RAM having a buffer 24 and the like, 26 is a print head, 27 is a carriage for moving the print head in the row direction, 28 is a paper feed mechanism, 29 to 31 are drivers for the print head 26, carriage 27 and paper feed mechanism 28. .

Now, the printer control CP provided in the printer of this embodiment is described.
The U20 uses a microprocessor in which the unit of data that can be processed at a time is 1 byte, and the print head 26 provided in this printer is described as a 24-pin type. That is, in the case of the 24-pin type print head 26, if the print data supplied from the host device, that is, the host computer, is converted into dot matrix print pattern data, one column of the print pattern data is composed of 3 bytes of bit data. It is necessary to divide each column of the print pattern data into three bit data groups of one byte each and perform data processing.

For this reason, the image buffer 24 for storing at least one line of the print pattern data includes:
In this embodiment, as shown in FIG. 2, the storage areas are divided into three storage areas A to C. Each of the storage areas A to C has a predetermined number A1 having a storage capacity of 1 byte.
~ An, B1 ~ Bn and C1 ~ Cn addresses. Note that the storage areas A to C of the image buffer may have a form as shown in FIG.

That is, each column of the print pattern data is divided into three groups of upper, middle, and lower bit data of 1 byte each, and the upper group of each column is stored in the storage area A of the image buffer 24, respectively. The group is set to be stored in the storage area B, and the lower groups are set to be stored in the storage area C.

Next, a printing operation in the printing apparatus of the present embodiment will be described.

The flowchart of FIG. 4 shows the main flowchart of the print control.

If it is determined in step S1 that data has been received from the host computer, the process proceeds to step S2.

In step S2, it is determined whether the received data is a character code. If it is a character code, the determination is YES, and the process proceeds to a normal printing write subroutine shown in FIG. 5 in step S5. If the code is a print control code such as a carriage return code, the determination is NO and the process proceeds to step S4. On the other hand, in step S4, it is determined in step S2 whether the received data is a carriage return code,
If NO is determined, the process proceeds to step S7, where the process according to the received data is performed, and then the process returns to step S1,
If YES, it is determined in step S6 whether or not the high-speed mode is set, and according to the result, step S8a or step S8a is performed.
8b, the subroutine of the printing process shown in FIG. 6 is executed.

Next, the normal printing writing process in step S5 in FIG. 4 will be described with reference to a subroutine flowchart in FIG.

First, in step S10, the character code is converted into dot matrix print pattern data, a maximum value CMAX of the number of columns of the print pattern data for one character is set, and a write column counter is initially set. Thereafter, in step S11, the write column counter is incremented by 2, and the process proceeds to step S12. In step S12, for example, a group of 1-byte high-order dot data in the X-th column (X is a variable) of the print pattern data is read. And put it in the storage area A of the image buffer 24
Write at address x. Subsequently, in step S14, a group of middle bit data of the same column is read, and in step S15, it is written to the address Bx of the storage area B of the image buffer 24. In step S16, a group of lower bit data in the same column is read, and in step S17,
Write at address x.

Thereafter, in step S18, it is determined whether or not the count number of the write column counter has become equal to twice the maximum value CMAX of the number of columns set in step S10. If the determination is NO, the process returns to step S11, and the processes of steps S11 to S18 are repeated. By repeating this, the print pattern data for one character is stored in the image buffer 24.
Is stored, the determination is YES in step S18, and the process proceeds to step S19.

In this step S19, in order to specify the write destination address in each storage area of the image buffer 24 when the next applied print pattern data is stored in the image buffer 24, the value of the write start address of each storage area is set in step S10. The maximum value CMAX set in step is added, and the process returns to step S1 of the main routine in FIG.

Next, the printing process in steps S8a and S8b in FIG. 4 will be described with reference to a subroutine flowchart in FIG. Here, step S8a corresponds to the case where the subroutine of FIG.
Step S8b corresponds to the case where the processing is started from the entry B in FIG.

In this embodiment, the number of continuous dots N to be extracted is three.

When the process is started from the entry A, first, the column counter is set to 1 in a step S20. Next, 2 is set to the counter in step S21. Step S22
Sets all bits of the processing buffer to 1 (initial setting).

Then, in step S23, the data of the column represented by the number obtained by subtracting 2 from the sum of the value of the column counter and the value of the counter is read from the line buffer, the logical product is calculated with the data in the buffer, and the result is stored in the buffer again. I do. Next, at step S24, the value of the counter is set to a predetermined value N2.
It is determined whether it is double, that is, 6. If the value of the counter is twice N, that is, if it is 6, the process proceeds to step S26, and if not, the process proceeds to step S25. In step S25, 2 is added to the value of the counter, and the process returns to step S23. Thereafter, this processing is repeated until it is determined in step S24 that the value of the counter has become twice N, that is, has become 6.

On the other hand, in step S26, the buffer data is a number obtained by subtracting 3 from the sum of the column counter value and the counter value, that is, a value obtained by subtracting 3 from the number obtained by adding N to the column counter value, that is, 6 plus N. Is stored in the line buffer as the data of the column represented by. Further, in step S27, the data in the buffer is negated and stored in the buffer again.

Then, in step S28, a column represented by a number obtained by subtracting 2 from the sum of the value of the column counter and the value of the counter, that is, a value obtained by subtracting 2 from the number obtained by adding N to the column counter value, that is, 6 And the logical product of the data of the buffer and the data of the column represented by the above-mentioned number are again stored in the line buffer. Further, step S29
The column data and buffer represented by the number obtained by subtracting 2 from the sum of the column counter value and the counter value, that is, the number obtained by subtracting 4 from the number obtained by adding N to the column counter value, that is, 6 + 6. And the logical product is again stored in the line buffer as column data represented by the above-mentioned numbers.

Then, in step S30, 2 is added to the value of the column counter. Next, it is determined in step S31 whether or not the value obtained by adding twice the value of the column counter to N, that is, 6 is larger than the last column. If it is larger, the process proceeds to step S32; otherwise, the process returns to step S21, and the same processing is repeated.

The thinning process is performed by the processes in steps S20 to S31 described above. If the normal mode is selected in step S6, the process starts from entry B and proceeds to step S2.
The processing of step S32 is directly performed without performing steps 0 to S31.

In step S32, the read column counter is initialized, and in step S33, the carriage 27 is driven to move the print pins of the print head 26 to the positions where printing is to be performed.
In step S34, the upper bit data at the address Ax in the storage area A of the image buffer 24 is read out, and this is set in the upper byte of the print head driver 29 in step S35, and B in the storage area B of the image buffer 24 is set in step S36.
Read the middle bit data at address x and store it in step S
At 37, the middle byte of the print head driver 29 is set, and at step S38, C in the storage area C of the image buffer 24 is set.
Read the lower bit data at address x, and read this in step S
At 39, the lower byte of the print head driver 29 is set.

Thereafter, in step S40, the print head 26 is driven to perform printing, and in step S41, it is determined whether the printing of one line is completed. If NO is determined, the process proceeds to step S42,
The read column counter is incremented by 1, and the process returns to step S33, and steps S31 to S42 are repeated. When printing for one line is completed by repeating this, YES is determined in step S41 and the process proceeds to step S43, where preparation is made so that print pattern data for the next line can be stored at the beginning of each storage area of the image buffer 24. Then, the process returns to step S1 of the main routine in FIG.

At this time, the time required to move the carriage 27 by two steps is set shorter than the time originally determined by the operation time of the print head 26. By doing so, it is possible to print a small number of continuous dots even during a very short time during which printing cannot be performed for the following reason.

FIG. 7 (a) shows the driving pulse signal in the normal continuous dot printing in the upper part, and the lower part shows the driving trajectory when driving the printing pin which is the dot print element of the print head according to the driving pulse signal. is there.

As shown in FIG. 8 (b), the drive pulse signal has a pulse width Tp and a period T. FIG. 8 (a) shows one driving trajectory of the print pin, the forward time a in which the print pin moves from the starting point to the sheet, the contact time b in contact with the sheet, and the return path returning from the sheet to the start point. Time c
Is shown.

FIG. 7 (b) shows the driving pulse signal for driving the print pin in a cycle shorter than the cycle for normal continuous dot printing in the upper part, and the drive locus of the print pin in the lower part. As is clear from this figure, if the period of the drive pulse signal is shortened, the print pins cannot follow, so that an incomplete print state occurs. However, as shown in the upper part of FIG.
If the drive pulse signal (shaded portion) corresponding to the third dot is deleted, printing may be possible. The reason is that the shortest printable period in normal continuous dot printing is equal to (forward time a + contact time b + return time c), but the drive pulse signal corresponding to the third dot of the continuous dots is deleted. Has 2 /
The printing operation can be repeated without any trouble until the time is about 3 (forward time a + contact time b + return time c).

Next, a second embodiment will be described. In the above-described embodiment, the value of the number N of the continuous dots to be extracted is described as 3, but in this embodiment, the case where N = 4 will be described.

The electrical configuration is the same as in the first embodiment described above.
As shown in FIG. 1, it is not specifically described here. Also,
The main routine is the same as in the above-described embodiment.

In the second embodiment, the steps of the main routine
Since the processing in S5 is different from that in the first embodiment, this is shown in FIG. The steps from step S51 to step S60 of the printing write subroutine of FIG. 9 are the same as the subroutine of the first embodiment except for step S52 and step S59. That is, at step S11 in FIG.
In FIG. 9, the increment is made to be step S52, and the value of the counter is increased by 3. Step S18 in FIG.
In FIG. 9, the value of the counter is compared with twice the value of CMAX in step S59, and the value is compared with three times the value of CMAX. The other processes are exactly the same as those in FIG.

Next, since the printing process of the main routine steps S8a and S8b is also different from that of the first embodiment, this subroutine is executed in the tenth embodiment.
Shown in the figure. In FIG. 10, step S62 is to increase the value of the counter by 2 in step S21 of FIG.
Increment the value of the counter by 3. Also, the steps in FIG.
In S23, the sum of the column counter value and the counter value is 2
Was read from the line buffer, the logical product was taken with the data in the buffer, and the result was stored again in the buffer. A similar process is performed with the data of the column represented by the number obtained by subtracting 3 from the sum of the values of the counter and the counter.

Also, in step S24 in FIG. 6, it was determined whether the value of the counter is twice the predetermined value N, that is, 6 or not. In FIG. 10, however, in step S65, the value of the counter is three times N. ,
That is, the same processing is performed in step 12. Step S25 in FIG.
In FIG. 10, the value of the counter is increased by 2. However, in FIG. 10, the value is incremented by 3 in step S66.

In step S26 of FIG. 6, the buffer data is obtained by subtracting 3 from the sum of the column counter value and the counter value,
That is, the data of the column counter is stored in the line buffer as column data represented by a value obtained by subtracting 3 from twice the value of N, that is, adding 6 to the value of the column counter. Column data expressed by the number obtained by subtracting 8 from the sum of the column counter value and the counter value, ie, 3 times N of the column counter value, that is, 12 minus 12. And store it in the line buffer. In step S26 in FIG. 6, after the processing is completed, the process proceeds to step S27, but in step S67 in FIG.
Then, when the processing is completed, the process proceeds to step S68.

In step S68, the buffer data is represented by the number obtained by subtracting 4 from the sum of the value of the column counter and the value of the counter, that is, the number obtained by subtracting 4 from the value obtained by adding 3 times N, ie, 12 to the value of the column counter. Is stored in the line buffer as the data of the column to be processed. When step S68 ends, the process proceeds to step S69.

In step S28 of FIG. 6, a value obtained by subtracting 2 from the sum of the value of the column counter and the value of the counter, that is, a value obtained by subtracting 2 from the value obtained by adding N to the column counter value, that is, adding 6, is used. The logical product of the data of the column represented and the data of the buffer was taken and stored again in the line buffer as the data of the column represented by the number described above. The logical product of the column data and the buffer data expressed by the number obtained by subtracting 3 from the sum of the counter values, that is, 3 times the value of the column counter, ie, 3 times N, ie, 12 minus 3. And store it again in the line buffer as column data represented by the above-mentioned number.

In step S29 in FIG. 6, a value obtained by subtracting 2 from the sum of the value of the column counter and the value of the counter, that is, a value obtained by subtracting 4 from the number obtained by adding twice the value of the column counter to N, that is, 6 is used. The logical product of the data of the column represented and the data of the buffer was taken and stored again in the line buffer as the data of the column represented by the number described above. The logical product of the column data and the buffer data represented by the number obtained by subtracting 6 from the sum of the counter values, that is, the number obtained by subtracting 6 from the value obtained by adding 3 to N, that is, 12 to the column counter value. And store it again in the line buffer as column data represented by the above-mentioned number. In step S29 in FIG. 6, the process proceeds to step S30 when the process is completed. In step S71 in FIG. 10, when the process is completed, the process proceeds to step S72.

In step S72, a value obtained by subtracting 9 from the sum of the value of the column counter and the value of the counter, that is, three times N, that is, a value obtained by subtracting 9 from the number obtained by adding 12 to the value of the column counter is subtracted by 9. The logical product of the data and the data in the buffer is calculated and stored again in the line buffer as the column data represented by the above-mentioned numbers. In step S72, when the process ends, the process proceeds to step S73.

In step S30 of FIG. 6, the value of the column counter is increased by 2. However, in FIG. 10, the process proceeds to step S73, and the value of the column counter is increased by 3. In step S31 of FIG. 6, it is determined whether the value obtained by adding twice the value of the column counter to N, that is, 6 is larger than the last column, but in FIG.
The same processing is performed at three times N, that is, at 12. The other processes are exactly the same as those in FIG.

By performing the processing as described above, the processing when the number N of consecutive dots to be extracted is 4 can be performed. Similarly, N
Can be operated in the same manner even when the number is 5 or more.

 Next, a third embodiment will be described.

The electrical configuration is the same as in the first and second embodiments described above, and will not be particularly described here. The main routine is the same as in the above-described embodiment. However, the image buffer used in this embodiment has twice the capacity of the above-mentioned one, and its storage area is divided into two parts to be used as two buffers.

In the third embodiment, the processing of step S5 of the main routine is different from that of the first and second embodiments, and this is shown in the subroutine of FIG.

In FIG. 11, the counter value is increased by 2 instead of increasing the counter value by 2 in step S11 in FIG. 5 of the first embodiment. In addition, what is compared with the value of the counter and twice the value of CMAX in step S18 in FIG. 5 is changed to step S99 in FIG. 11, and is compared with the value of CMAX. The other processes are exactly the same as those in FIG.

Next, since the processing of steps S8a and S8b of the main routine is also different from the first and second embodiments, this is shown in the subroutine of FIG.

First, when step S8a is selected in the main routine of FIG. 4, the process starts from entry A of FIG.
In step S101, the column counter is set to 3. Then, in step S102, the data of the first column is copied to the first column of the second line buffer. Further, in step S103, the data of the second column is copied to the third column of the second line buffer.

Then, in step S104, the logical product of the column data indicated by the number obtained by subtracting 1 from the column counter and the column data indicated by the number obtained by adding 1 to the column counter is calculated. Next, in step S105, the data is negated, and in step S106, the logical product of the data and the data of the column indicated by the column counter is calculated. In step S107, this data is stored in a column indicated by a number obtained by subtracting 1 from twice the column counter of the second line buffer.

Then, in step S108, the data calculated in step S106 is negated, and in step S109, the logical product of the data and the data of the column indicated by the column counter is calculated. In step S110, this data is stored in a column indicated by twice the column counter of the second line buffer.

In step S111, the data calculated in step S108 is negated, and in step S112, the logical product of the data and the data of the column indicated by the number obtained by adding 1 to the column counter is calculated. In step S113, this data is stored in the column indicated by the number obtained by adding 1 to the column counter.

In step S114, it is determined whether the value of the column counter is the last column. If so, step S1
Proceed to step 16, otherwise proceed to step S115. In step S115, the column counter is incremented by 1, and the process proceeds to step S104.

Since the processing after step S116 uses the second line buffer and performs the same processing as in FIG. 6, no particular description will be given.

The data of the column indicated by the column counter is Sn, the data of the column indicated by the number obtained by subtracting 1 from the column counter, and the data of the column indicated by the number obtained by adding 1 to the column counter are Sn-1 and Sn + 1, respectively. The data of the column indicated by the number obtained by subtracting 1 from twice the column counter of the second line buffer is dn1, and the data of the column indicated by twice the column counter of the second line buffer is dn.
Assuming n2, the processing shown in steps S104 to S107 can be represented by the following equation.

Similarly, the processing shown in steps S108 to S110 and the processing shown in steps S111 to S113 can be represented by the following equations, respectively.

dn2 = ▲ ▼ * Sn Sn + 1 ← ▲ ▼ * Sn + 1 On the other hand, if step S8b is selected in the main routine of FIG. 4, the processing is started from entry B of FIG. Processing is performed using a line buffer.

The example in which the present invention is applied to the high-speed mode of the printer having the high-speed mode and the normal printing mode has been described above, but the present invention is also effective for a single-speed printer corresponding to the high-speed mode in this embodiment. For example, a Japanese printer can print by switching between horizontal writing and vertical writing. However, if high-speed printing is to be performed with the above-described apparatus and the above-described processing is not performed, two types of printing are performed. Fonts are required and a large character generator ROM is required. However, by using the configuration of the present invention, it is possible to create both vertical and horizontal high-speed character fonts from a single character font.

[Effects of the Invention] As described above, according to the present invention, a basic dot pattern corresponding to external input data is read from a storage unit,
After searching the basic dot pattern for each dot row and extracting a predetermined number of N consecutive dots,
Since the print data of at least one of the extracted N consecutive dots is deleted, there is an effect that printing can be performed at a higher speed than the print speed determined by the speed at which the print head can operate.

[Brief description of the drawings]

1 is an overall control block diagram of a printing apparatus, FIGS. 2 and 3 are print pattern data storage diagrams of an image buffer, FIG. 4 is a main flow diagram, FIG. FIG. 6 is a flowchart of a subroutine of the first embodiment, FIG. 7 (a) is a timing chart showing a conventional drive pulse signal and the associated drive locus of a print pin, and FIG. 7 (b) is the present invention. FIG. 8 (a) showing a driving pulse signal and a driving trajectory of a printing pin associated therewith.
FIG. 8B is a detailed view of the drive pulse signal, FIGS. 9 and 10 are subroutine flowcharts of the second embodiment, and FIGS. It is a subroutine flowchart of 3rd Example. 20: Printer control CPU 21: ROM 22: RAM 24: Image buffer 26: Print head 27: Carriage

Continuation of the front page (56) References JP-A-63-116859 (JP, A) JP-A-63-1116858 (JP, A) JP-A-2-92560 (JP, A) (58) Fields studied (Int .Cl. ⁶ , DB name) B41J 2/485

Claims (1)

(57) [Claims] 1. A print head having at least one row of a plurality of dot print elements each capable of printing one dot on a print medium, and the print head and the print medium substantially intersecting with the row of the dot print elements. Moving means for relatively moving along the printing direction, driving means for driving the print head, storage means for storing a dot pattern representing the presence / absence of printing and a print timing position, and storage means for storing the dot pattern. A printing control means for printing on the printing medium by controlling the moving means and the driving means in accordance with the dot pattern. A continuous dot extracting means for retrieving a predetermined number of N consecutive dots by searching for each dot; A new dot is created based on the continuous dot, and the dot is arranged at a print timing position between the dots except for the first dot of the N continuous dot, and the first dot of the N continuous dot is created based on the new dot. A printing apparatus comprising: dot data changing means for changing dots other than dots.