JPH0533913B2 - - Google Patents

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Prior art (Figures 3 and 4) Problems to be solved by the invention Means for solving the problems (Figure 1) Functional Embodiment (a) Description of one embodiment (Fig. 2) (b) Explanation of another embodiment Effects of the invention [Summary] Banded bitmap type page printer for a fraction of a page as a bitmap memory In order to prevent a drop in throughput, a pair of code memories for one page is provided, and if the remaining amount of data to be read to the bitmap memory exceeds a certain value, writing of the contents of one code memory to the bitmap memory is stopped. , which speeds up continuous printing by writing print data to other code memories.

[Industrial application field]

The present invention relates to a page printer control device that improves throughput when a band bitmap memory is used as the bitmap memory in a page printer such as a laser printer or an LED printer.

In recent years, the prices of page printers such as laser printers, LED printers, and liquid crystal printers have decreased significantly.

In these printers, it is necessary to store one page's worth of print bit patterns in a bitmap memory in advance, and there are two methods for this: a full-page bitmap method and a band bitmap method.

The full page bitmap method has a bitmap memory with a capacity of one page, while the band bitmap method has a bitmap memory with a capacity of a fraction of a page.

Therefore, although the band bit map method can reduce the memory capacity and reduce the cost, it may reduce the throughput, and there has been a demand for improvements in this area.

[Conventional technology]

FIG. 3 is a block diagram of a conventional page printer control unit using the band bitmap method.

In the figure, 1 is a code memory that stores print data for one page, 2 is a pattern conversion memory (means) that converts the print data in the code memory 1 into a corresponding print bit pattern, 3 4 is a bit map memory that stores bit patterns for a fraction of a page, and 4 is a control unit that is composed of a microprocessor and controls read/write of the code memory 1 and read/write of the bit map memory. It performs write control, etc., and is the write address register 4 of the code memory 1.
0, read address register 41, bitmap memory write vertical (Y) address register 42
5 is a data transfer circuit which reads one line of bit pattern from the bit map memory 3 in response to a periodic synchronization signal from the printing mechanism control section 9, converts it from parallel to serial, and converts it into one line. 6 is an address switching circuit that transfers the serial data of 1 to the printing mechanism control unit 9, and
7 is a data switching circuit that switches between the write data bus B2 side a and the read address side B2 by the bus switching signal 4 (referred to as MPU). 8 is a read address section, which has a read horizontal address register and a read vertical address register;
Reference numeral 9 denotes a printing mechanism control section, which performs recording (printing) one line at a time in synchronization with print feeding, and obtains one line of serial data from the data transfer circuit 5 in response to a synchronization signal.

FIG. 4 is an explanatory diagram of the prior art.

When using band bitmap memory,
Since there is not enough capacity for one page, ring buffer control is used. That is, as shown in FIGS. 4A, B, and C, it has vertical address pointers R and W on the read side and write side, and controls to return to the beginning when the end point of the memory 3 is reached on both the read side and write side. use

On the other hand, in the code memory 1, the print data is sorted for each line and stored as shown in FIG. ), and the amount of data for each line varies depending on the number of characters to be printed.

To read and write to this bitmap memory 3, as shown in FIG.
Yr horizontal address Xr from register section 8 to bus B4
The read data is applied to the bitmap memory 3 via the bus B5, and the read data is applied to the data transfer circuit 5 via the bus B5. After incrementing the horizontal address Xr and reading one line of data, the data transfer circuit 5:
The read data is converted from parallel to serial and transferred as serial data.

This transfer period after reading is used to write the pattern in the bit map memory 3. After the read operation of the memory 3 is completed, the MPU 4 switches the switching circuits 6 and 7 to the a side by the bus switching signal, and then switches the vertical address
Yw is sent from the register 42 via bus B3, the horizontal address This is done by giving

In this way, reading and writing are performed alternately to the bit map memory 3, giving priority to reading over printing, and one page's worth of bit patterns is output under the ring buffer control shown in Fig. 4 A, B, and C. Ru.

[Problem that the invention seeks to solve]

In such conventional technology, printing starts only after one page of print data is stored in the code memory 1.

Therefore, as shown in FIG. 4F, the code memory 1
After writing the print data to the bit map memory 3, writing of the bit pattern to the bit map memory 3 and reading of the bit pattern from the bit map memory 3 are executed. After the printing of one page is completed, the operation of writing one page of print data into the code memory 1 is performed again.

For this reason, in the conventional technology, after printing one page, printing cannot be started until writing to code memory 1 is finished, and writing to code memory 1 ends while loading the next sheet after finishing one page. If not, continuous printing will not be possible and throughput will be reduced.
This has been an obstacle to increasing the speed of such band bit map printers.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a page printer control device that prepares data for the next page while printing one page and enables continuous printing.

[Means for solving problems]

FIG. 1 is a diagram explaining the principle of the present invention.

In FIG. 1A, the same parts as those shown in FIG. is a determination means, which uses the write address (vertical address Yw) and read address (vertical address Yr) of the bit map memory 3.
This is to determine whether there is enough room for writing to the bitmap memory 3.

Then, when there is room for writing, print data for the next page is written in the code memory that is available during the write cycle.

[Effect]

The reading time to the bit map memory 3 is constant because one line is read, whereas the writing time varies depending on the number of characters in one line, etc.

Therefore, on the bitmap memory 3, FIG.
As shown in FIG. 2, the remaining read amount indicating the unread bit pattern may change as d ₁ and d ₂ .

The remaining read capacity can be determined from the difference between the read address and the write address of the bit map memory 3, and when there is a margin for writing (the remaining write capacity is large), the bit map memory 3 The writing of the bit pattern to the code memory 1a or 1b is stopped, and the print data of the next page is written to the vacant code memory 1a or 1b.

Therefore, since the print data for the next page can be prepared while printing one page, the time required to store the print data in the code memory 1 after printing one page can be shortened, making continuous printing possible and reducing throughput. will improve.

〔Example〕

(a) Description of one embodiment FIG. 2 is a configuration diagram of an embodiment of the present invention.

In the figure, the same parts as those shown in FIGS. 1 and 3 are indicated by the same symbols, and 10a is a deviation circuit, which is the deviation (absolute value) between the write vertical address Yw and the read vertical address Yr. Those who take 1
0b is a comparison circuit that compares the deviation of the deviation circuit 10a with a predetermined value n, and issues a margin signal to the MPU 4 if the deviation is greater than or equal to the predetermined value n; 40a, 40b;
are each write address registers,
41a and 41b respectively give write addresses to code memories 1a and 1b, and read (read)
address registers, each code memory 1
43 is a predetermined value register that stores a predetermined value n, which is a limit value; 11 is a memory switching circuit that connects pattern conversion memory 2 and code memory 1;
The connection with a and 1b is switched by a memory switching signal from the MPU 4.

Next, the operation of the configuration shown in FIG. 2 will be explained.

First, a write address is given to the code memory 1a from the register 40a, write data (print data) is given to the bus B1, and print data for one page is stored.

When one page of print data has been stored, the memory switching circuit 11 is set to the d side by the memory switching signal, and the code memory 1a and pattern conversion memory 2 are switched to the d side.
Connect and start printing.

That is, as described above, in response to the data transfer end signal, the MPU 4 switches between the switching circuits 6, 6, and 6 in response to the bus switching signal.
7 to the b side, and the bit pattern indicated by the read address is read from the bit map memory 3 to the data transfer circuit 5. During the transfer of serial data from the data transfer circuit 5 to the printing mechanism control section 9, the switching circuits 6 and 7 are switched to the a side by the bus switching signal, and the contents of the code memory 1a are converted into a bit pattern by the pattern conversion memory 2. It is converted and written to the location on the bitmap memory 3 indicated by the write vertical address Yw and horizontal address Xw via the bus B2.

In this way, bit pattern reading/writing to the bit map memory 3 is alternately repeated with read priority. Note that the read vertical address Yr increments every time a data transfer end signal arrives.

On the other hand, in the determining means 10, the deviation circuit 10a calculates the deviation between the write vertical address Yw and the read vertical address Yr, and the comparison circuit 10b compares the deviation with a predetermined value n of the register 43.

If writing to the bit map memory 3 is faster than reading to the data transfer circuit 5, the difference between the amount of data written to the bit map memory 3 and the amount of data read out (read amount) becomes large, and the deviation becomes larger.

If this deviation exceeds a predetermined value n, the comparison circuit 10b
issues a margin signal to MPU4.

MPU4 issues a memory switching signal in response to this,
The memo switching circuit 11 is connected to the c side as shown in FIG.
The connection between the code memory 1a and the pattern conversion memory 2 is cut off.

Therefore, writing of the bit pattern to the bit map memory 3 is interrupted.

During this time, MPU4 writes write address register 4.
0b, a write address is given to the print data from the bus B1, and the print data of the next page is stored in the code memory 1b.

During this time, the switching circuits 6 and 7 are set to the b side by the path switching signal, so that data can be read from the bitmap memory 3 to the data transfer circuit 5 at any time.

The MPU 4 monitors the margin signal of the determination means 10,
When the deviation (read remaining amount) of the deviation circuit 10a becomes small and becomes less than the predetermined value n, and no margin signal is emitted from the comparison circuit 10b, the MPU 4 switches the memory switching circuit 11 to the d side using the memory switching signal. The code memory 1a and pattern conversion memory 2 are connected again. Therefore, in the write cycle, a bit pattern corresponding to the print data in the code memory 1a is written into the bitmap memory 3.

When the printing operation for one page is thus completed, the MPU 4 writes the remaining amount of print data for the next page into the code memory 1b and starts printing. At this time, in order to write to the bitmap memory 3, the memory switching circuit 11 switches to the c side.
Code memory 1b and pattern conversion memory 2 are connected.

In this way, the print data for the next page can be prepared during the printing operation of one page, and the time from the end of printing one page to the start of printing the next page can be shortened.

(b) Description of other embodiments In the above embodiment, the bitmap memory 3
When the remaining amount of read data becomes large, the print data is written to the code memory 1b not only in the predetermined write cycle but also in the read cycle. It's good to wear.

Further, although the remaining read amount is determined by comparing vertical addresses, that is, by comparing the number of lines, it may also be determined by comparing the number of bytes.

Furthermore, although the bit map memory 3 is read every byte of one raster, the cycle may be determined such that, for example, 2 bytes are read and writing is performed while 2 bytes are being transferred.

Although the present invention has been described above with reference to examples, the present invention can be modified in various ways according to the gist of the present invention.
These are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects are achieved.

Even if one page of data is being written to the band bitmap memory, which alternately writes and reads data, if there is enough room to write, the writing is interrupted and the next page of print data is prepared in the code memory. Even if an inexpensive band bitmap memory is used, the throughput during continuous printing can be improved.

Since the write margin is determined by comparing the write address and the read address of the band bit map memory, the write margin can be easily and accurately determined.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, and FIG. 3 is a configuration diagram of a prior art.
FIG. 4 is an explanatory diagram of the prior art. In the figure, 1, 1a, 1b...code memory, 2...
. . . pattern conversion memory, 3 . . . bitmap memory, 4 . . . control section, 10 . . . determination means.

Claims (1)

[Scope of Claims] 1. A code memory 1 that stores print data for one page, a pattern converting means 2 that converts the contents of the code memory 1 into a bit pattern to be printed, and a bit pattern for a fraction of a page. a bit map memory 3 capable of storing a pattern; a write cycle for writing the bit pattern into the bit map memory 3 according to a write address;
In a page printer control device that outputs bit patterns to be printed for one page by alternately executing a read cycle of reading out the bit pattern from the bit map memory 3 according to the read address, the code memories are arranged in a pair 1a and 1b. and determining means 10 for comparing the write address and the read address to determine whether there is enough room for writing into the bit map memory 3, and interrupting the writing when there is enough room for writing to the bitmap memory 3. During the write cycle, the pair of code memories 1a, 1b
A page printer control device characterized in that print data for the next page is written into a vacant code memory.