JPH02190372A - Data prefetching control system for printer - Google Patents

Abstract

PURPOSE:To improve processing efficiency by limiting data prefetching when a designated line feeding amount is larger than a difference between the length of a sheet and a sheet feeding length at the time of execution of a line feed command in a printing process of second or following sheet. CONSTITUTION:A main controller 20 sorts the content of data prefetching control of first and second and following sheets to be continuously printed. It counts the whole line feeds by a sheet length counter 18 in the sheet printing, measures a sheet length l by the number of lines, and uses it for the data prefetching control in the second or following sheet printing. In the second or following sheet printing, the line feeding amount (t) is counted by a sheet feeding length counter 19 for each line feed command, accumulated, and the sheet feeding length (m) from the head of the sheet to the present printing line is measured by the number of lines. Then, a difference (l-m) is calculated to obtain the effective number of remaining printable lines, which is compared with the line feeding amount (t) of a line feed command to be executed next. Only in case of (l-m)>=t, data prefetching is executed. That is, the line feed is executed, but data prefetching is not conducted, and subsequent data is printed on next sheet.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a print data prefetch control method for improving throughput in a printer.

The purpose is to improve processing efficiency by making the restrictions on data preemption more limited.

In a printer that can receive and print data line by line from a main unit and can also pre-fetch the next data from the main unit during a feed feed operation.

A paper length link and paper feed length counter are provided.

When printing the first sheet of paper, the paper length is determined by counting the total line feed amount using the paper length counter.

In the printing process for the second and subsequent sheets of paper, the paper feed length counter sequentially counts the line feed amount specified by each line feed command to determine the paper feed length to the current position, and when the line feed command is executed, the line feed length specified by the line feed length is The configuration is configured to restrict data prefetching when the difference is greater than the length and paper feed length.

[Industrial application field]

The present invention relates to a print data prefetch control method for improving throughput in a printer.

A printer that receives print data line by line from the main unit and performs print processing requests the print data of the next line from the main unit before the printing process is completed, and transfers the print data of the second line to the current print. The printer's processing speed is increased by executing it in parallel with the processing.

However, if the next line runs out of paper and cannot be printed, the prefetched data will be lost, so when one paper out is detected, data prefetching is prohibited.The present invention prevents this data prefetching prohibition control. It increases efficiency.

[Conventional technology]

FIG. 4 is a schematic diagram of a conventional serial type printer. In the figure, 1 is a paper stacker, 2 is a print head,
3 is a platen, 4 is a paper out sensor, and 5 is paper.

The sheets 5 are fed one by one from the stacker 1 in accordance with a sheet feed command from the main unit, and printed on the platen 3 by the printing pad 2.

Paper out sensor 4 detects the presence/absence of paper 5,
- Outputs a paper out signal when detecting the absence of paper.

The condition under which the printer can request the main unit to prefetch the next line data is that it can be guaranteed that the prefetched next line data will be reliably printed.

For this purpose, it is necessary that a printable area remains on the paper as a result of executing the line feed according to the line feed amount specified by the line feed command in the current print data.

However, in conventional printers, the paper out sensor 4 is provided at a position quite far from the printing position of the print head 2, and the paper out sensor 4 detects the state before the paper actually runs out at the printing position. When detecting the middle of paper 5, the length of the printable area after the line position currently being printed is unknown, so strict detection of the data prefetching conditions as described above is not possible, and a simpler method is used. A standardized method was adopted.

The data prefetch control method in conventional printers is
This will be explained using figures.

Tal in FIG. 5 is the last printable line position of the paper 5.

In other words, it is an operating state in which printing is performed at the position immediately before the paper runs out, the paper out sensor 4 does not detect the paper 5, and the end of the paper 5 at this time (referred to as the paper out position) and the paper out position are in the operating state. Let the distance between the cut sensor 4 be n.

fbl in FIG. 5 shows the printing operation state when the paper out sensor 4 is detecting the paper 5, going back from the state in (a). In this state, if the line feed command indicates a line feed amount (referred to as t) that is greater than or equal to the distance Mn, even if there is still a printable area of length k remaining, it is assumed that the paper is out of paper. It is handled in the same way, without prefetching data, and requests the next line data from the main device after completing the current printing process.

In this way, in the conventional printer data prefetch control method, data is prefetched only when the paper out sensor 4 detects the paper 5 and the line feed 11t specified by the 9th line feed command is less than the fixed value n. That's what I do.

FIG. 6 shows a control flow of print processing in a conventional printer that performs such data prefetch control.

When paper is fed by a paper feed command, a printing operation is started and one line of print data received from one main unit is sequentially analyzed.

■, ■, ■ identify commands; ■ identifies a print command, ■ identifies a line feed command, and ■ identifies a discharge command.

In the case of a print command, press ■ to wait until the line feed is finished, and then press ■ to print.

In the case of a line feed command, if the specified line feed amount [is smaller than n (see FIG. 5), then ■ is executed, otherwise, ■ is executed. In step (2), check whether the paper out sensor is detecting paper or not. If it is detected, execute (2); otherwise, execute (2). ■ is the operation when the data prefetching condition is satisfied.

Activate the change operation, finish the process without waiting for it to finish (execute in the leave-behind method), and request the next line data from the main device with @. On the other hand, {circle around (2)} is an operation when the data prefetching condition is not satisfied, in which a new line operation is started, and after waiting for its completion, a @ next line data request is made.

For the eject command, press ■ to eject the paper.

[Problem to be solved by the invention]

In the conventional printer's data prefetch control method.

The data pre-fetching condition is not strict, and it is determined whether the line feed amount specified by the line feed command exceeds the distance value n between the paper out position and the paper out sensor position, and the paper out sensor detects the paper. It was determined whether to pre-fetch the data or wait for the end of the line feed to request the data. Therefore, even if a printable area remains after a line feed, data prefetching may not be performed, which reduces the processing efficiency of the printer.

The present invention aims to improve processing efficiency by making restrictions on data prefetching more limited.

[Means to solve the problem]

In the present invention, for the line feed amount t specified by the line feed command,
To accurately determine whether or not data can be prefetched, and to prevent data prefetching from being restricted even though printing after a line feed is possible.

Therefore, during the printing process of the first sheet, the paper length l is measured,
In addition, when printing the second and subsequent sheets of paper, measure the paper feed length m from the beginning to the current one, calculate the remaining printable number of lines from the difference (j! - m), and calculate this by the specified line feed amount t of the line feed command. as long as it does not exceed.

Control to prefetch data.

FIG. 1 is a diagram showing the basic configuration of the present invention.

In FIG.

10 is a main unit including a CPU.

11 is a serial type printer.

12 is a print head.

13 is a platen.

14 is a paper out sensor.

15 is paper.

16 is a carrier motor (CRM) that controls the feeding of the print head 12.

17 is a line feed motor (
LFM).

18 counts the total line feed feed amount of the paper 15.

This is the paper length counter.

Reference numeral 19 denotes a paper feed length counter that counts the amount of line feed from the beginning of the paper 15 to the present.

20 is a main control unit that controls the interface with the main unit 10, analyzes the print data received from the main unit W 10, and responds to commands such as print commands, line feed commands, paper feed commands, ejection commands, etc. control, and also executes data prefetch control.

21 is a print command control unit that performs control corresponding to the print command, and includes a print head 12, a carrier motor (
CRM) 16 to execute printing.

22 is a line feed command control unit that performs control corresponding to line feed commands, and a line feed motor (LFM) 17
to execute line feed.

23 is a paper feed command control unit that performs control corresponding to the paper feed command;
5 is fed and set at the printing operation start position on the platen 13.

Reference numeral 24 denotes a discharge command control section that performs control corresponding to the discharge command, and discharges the paper 15 on which printing has been completed.

The main control unit 20 separates the contents of the data prefetch control depending on the first sheet of paper and the second and subsequent sheets of paper to be continuously printed.

The printing process for the first sheet of paper is the same as the conventional method.

When the paper out sensor 14 is detecting the paper 15, the fixed distance tlAn between the paper out position and the paper out sensor 14 position is compared with the line feed amount t of each line feed command, and n>
Data prefetching is performed only if t.

Also, when printing this first sheet of paper, the paper length counter 18
All line feeds are counted, and the paper length i is measured in terms of the number of lines, and this is used in data prefetch control in the printing process for the second and subsequent sheets.

In the printing process for the second and subsequent sheets of paper, the paper feed length counter 19 counts and accumulates the line feed amount t for each line feed command, and measures the paper feed length m from the top of the paper to the current print line in number of lines. Calculate the zero-order difference (j!-m) to find the remaining number of effective lines that can be printed, compare this with the line feed amount t of the line feed command to be executed next, and (Il-m)≧ Execute data prefetch only at time t. In other words, (I!, -
m) If <t, there will be no valid printable lines left on the paper after a line feed of t, so a line feed will be performed but data will not be read in advance, and the following data will be printed on the first sheet. will be done.

[For production]

According to the configuration of the invention shown in FIG.

When printing data continuously using multiple sheets of the same size paper, use the first sheet to measure the paper length l.

Data prefetching control is performed using a simple conventional method, and for the second and subsequent sheets, it is possible to accurately determine whether data prefetching can be restricted based on the paper length l measured during processing of the first sheet and the paper feed length m indicating the current line position. It is controlled so that the data is pre-fetched to the very limit possible.

This allows you to print a large number of sheets of paper continuously.

The rate at which data is prefetched increases, improving processing efficiency.

〔Example〕

FIGS. 2 and 3 show the overall control flow of a printer according to two embodiments of the present invention.

FIG. 2 shows the control flow of the printing process for the first sheet of paper. FIG. 3 shows the control flow of the printing process of the second and subsequent sheets.

Hereinafter, the operation of the embodiment will be explained with reference to FIGS. 2 and 3 while referring to the configuration shown in FIG. 1.

In the process of the first picture in Fig. 2.

In (2), the first sheet of paper is fed by a paper feed command.

Also clears the paper length counter. Paper feed length counter 19 is not used.

The print data received from the main device is sequentially analyzed, and the print command is identified in ■, the line feed command is identified in ■, and the discharge command is identified in ■.

In the case of a print command, if a line feed is not being executed, immediately, or if a line feed is being executed, press ■ to wait for the end, press ■ to execute printing, and return to ■.

In the case of a line feed command, use ■ to add the line feed amount t specified by the command to the paper length counter 18. Next, use ■ to check whether t<n is satisfied, and if so, press ■ to activate the paper out detection sensor. Check whether paper is detected,
If paper is detected, a line feed operation is activated with [stock], the line feed command processing is terminated without waiting for the end of the operation, and the next data is requested 8 with @, that is, the data is preempted. on the other hand,
If t≧n or the paper out sensor 14 does not detect paper in ①, a change operation is performed with 0, and after waiting for the end, the next data is requested with ◎. That is, requesting data in a non-preemptive manner.

In the case of a discharge command, the line feed is performed until the paper runs out in {circle around (2)}, the amount of feed at that time is added to the paper length counter 18, and the paper is discharged in [phase]. At this time, the paper length counter 18
The number of line feeds corresponding to the paper length l is set in .

Next, processing begins for the second and subsequent images in FIG. When the paper feed command is received, the paper is fed in step (3) and the paper feed length counter 19 is cleared at the same time.

Next, use [phase], @, @ to print commands and line feed commands.

Identifies discharge commands and performs corresponding controls,
The [phase] and [phase] steps performed for the print command and the 0 step performed for the ejection command are the same as in the processing of the first sheet in FIG. 2, so a description thereof will be omitted here.

In the case of a line feed command, the line feed lit is added to the paper feed length counter 19 in (■) to obtain the paper feed length m. Here, the line feed amount specified by each line feed command from the beginning of the paper to the present is Ll+L! +...t, 1m is expressed as follows.

m= Σ Mugogoning1 Next, use @ to determine whether the line feed amount t(tr) is smaller than (j!-m), and j! - If m≧t, press ◎ to start the line feed operation, immediately end the line feed command processing, and use @ to request the next data.

If 1-m<t, start the change action, wait for the end of the action, and return to (2). In the latter case, the ejection command will be processed next in [phase].

The operation according to the control flow in FIG. 3 is repeated as long as data continues.

〔Effect of the invention〕

In the present invention, it is possible to reliably know whether or not there are valid lines left to print after the line feed when printing the second and subsequent sheets, so data prefetching is not excessively restricted when executing the line feed command, and the printer processing efficiency and throughput are improved.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of the present invention, FIG. 2 is a control flow diagram of the first page printing process of the printer according to the embodiment of the present invention, and FIG. FIG. 4 is a schematic diagram of a conventional printer. FIG. 5 is an explanatory diagram of a data prefetch control method of a conventional printer. FIG. 6 is a control flow diagram of a conventional printer's print processing. . In Figure 1. lO: Main unit. 11: Printer. 12: Print head. 13 Nibraten. 14: Out of paper sensor. 15: Paper. 18: Paper length counter. 19: Paper feed length counter. 20: Main control unit. 21: Print command control unit. 22: Line feed command control section. 23: Paper feed command control unit. 24; Ejection command control unit. Patent applicant: Pfn Co., Ltd. Attorney: Patent attorney: Fumihiro Hase (2 others)
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Claims (1)

[Scope of Claims] A printer capable of receiving and printing data line by line from a main unit and also pre-fetching the next data from the main unit during a feed feed operation, which is provided with a paper length counter and a paper feed length counter, When printing the second sheet of paper, the paper length counter counts the total line feed amount to determine the paper length, and when printing the second and subsequent sheets, the paper feed length counter uses the paper feed length counter to determine the line feed length specified by each line feed command. Data in a printer characterized in that the paper feed length to the current position is determined by sequentially counting the paper feed length, and data prefetching is restricted when the line feed amount specified by the line feed command is larger than the difference between the paper length and the paper feed length when a line feed command is executed. Preemptive control method.