JP2008018584A - Line printer and printing control method of line printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a printing control method of line printer for establishing the suitable printing speed based on an actual transmission rate of the printing data transmitted from a host computer. <P>SOLUTION: A line thermal printer 1 acquires an amount of data of the printing data for every one line according to the printing method with a line thermal head 8 which is developed to a printing buffer 9 as an effective transmission rate from the printing data received per unit time from the host computer 30 (processes ST3, ST4). An upper-limit value of the printing speed of the line thermal head 8 is established based on the acquired effective transmission rate (processes ST5, ST6). While a drive control means 13 controls the printing speed of the line thermal head 8 so that the printing speed may become below the established upper-limit value, the printing is performed with controlling the conveyance speed of a recording paper 4 (process ST7). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a line printer that changes a printing speed based on an actual transfer rate of print data transmitted from an external device.

  As a printer that is connected to a register device in a store and prints an account statement or a coupon, a line thermal printer that performs printing line by line while conveying roll paper is widely used. In recent years, since the printing speed of line thermal printers has improved, the print data sent from the register device cannot keep up with the printing of each line of the line type print head, and the line thermal printer is waiting for the reception of print data. May stop for that.

When print data reception waits frequently and the line thermal printer repeats printing and stopping, the roll paper feed amount fluctuates before and after that. As a result, the printing pitch is disturbed and the printing density is changed to cause uneven printing, resulting in a deterioration in printing quality. In order to avoid such a problem, for example, Japanese Patent Application Laid-Open No. H10-228707 describes a technique for controlling the printing speed of a line printer from a host computer to prevent waiting for receiving print data. For example, Japanese Patent Application Laid-Open No. 2003-228561 describes a method in which a host computer controls the communication clock of a line printer to maintain a high communication speed between the two to prevent waiting for receiving print data.
JP 2003-50777 A JP-A-9-146724

  However, in the method of controlling the printing speed and communication clock of the line printer connected to the host computer, it is necessary to install an application and hardware for controlling the line printer in the host computer.

  Even if the communication speed between the host computer and the line printer can be maintained at a high speed, depending on the processing efficiency of the application installed in the host computer and the format of the transferred data, However, there is a problem that the speed at which the received print data is developed in the print buffer is not in time for printing of one line of the line type print head, and the line thermal printer stops because it waits for print data.

  In view of these points, the problem of the present invention is that the line printer itself controls the printing speed based on the actual transfer rate of the print data transmitted from the host computer, so that the print data can be received. The object is to propose a print control method for a line printer that does not stop printing. Another object of the present invention is to propose a line printer that performs printing by the printing control method.

In order to solve the above-described problem, the present invention provides a print control method for a line printer that prints print data received from an external device line by line by a line-type print head, wherein the received print data is transferred to the line. For each line by the printing head, an effective transfer rate acquisition step for acquiring the effective transfer rate from the amount of data developed in the print buffer, the reception time for receiving the print data, and printing for each line of printing An upper limit speed calculating step in which the line printer calculates and stores an upper limit speed of the line-type print head based on the effective transfer rate so as not to cause a print interruption state for data reception waiting, and the upper limit An upper limit setting process for setting the speed as the upper limit of the printing speed, and the line type print head is driven at a printing speed less than the set upper limit. While, the recording medium is conveyed at a conveying speed corresponding to the printing speed, to a printing step for performing the printing, comprising a.

  According to the present invention, the line printer itself acquires the effective transfer rate from the received print data, and the line printer itself sets the upper limit value of the print speed based on the effective transfer rate. Further, printing is performed by controlling the printing speed of the line type print head and the conveyance speed of the recording paper so that the printing speed is equal to or lower than the set upper limit value. Therefore, if the effective transfer rate is low, the print speed of the line printer should be slowed regardless of the communication speed between the external device such as the host computer and the line printer and the processing efficiency of the application installed in the host computer. Can do. As a result, it is possible to prevent printing from being interrupted every time one line of the line-type print head is waiting for reception of print data, resulting in fluctuations in the feeding amount of the recording paper and disturbing the print pitch. The printing quality can be kept high by avoiding the occurrence of uneven printing due to the change in printing density.

  In the present invention, the print mode determination step for determining whether or not the print mode does not require the reception of print data, and the print mode that does not require the reception of print data in the print mode determination step. If determined, it is preferable to include a maximum speed printing step of driving the line type print head at a maximum printing speed regardless of the effective transfer rate. In such a print mode, there is no need to wait for reception of print data, so printing can be performed at the maximum print speed originally provided by the line printer.

  Here, as a print mode that does not require waiting for reception of the print data, there is a mode in which printing is started after the received print data is stored in the print buffer up to the break of the print data.

  In the present invention, the effective transfer rate acquisition step receives a print data transmitted from the external device, and detects a control command indicating a print data break in the print data in the reception step. A transaction time measuring step of measuring a transaction time from the control command to the next reception of the same control command as the control command, and the print data received at the measured transaction time is developed in the print buffer 1 A data amount measurement step for measuring the amount of print data for each line, a transfer rate acquisition step for sequentially acquiring a print data transfer rate from the measured transaction time and the measured data amount, and a sequential acquisition Average transfer rate acquisition step of averaging the transfer rates to obtain an average transfer rate; It includes and is preferably obtains the effective transfer rate the average transfer rate at a predetermined timing. In this way, as an effective transfer rate, it is possible to obtain an average value of the average transfer rates at which the print data for each line according to the print format by the line type print head is developed in the print buffer. When the application installed in the host computer connected to the line printer is specified and the communication environment connecting the host computer and the line printer does not change, the print data received per unit time is expanded in the print buffer. Since the amount of print data to be converged converges, the average value of the average transfer rate also converges accordingly. Therefore, if the value is acquired as the effective transfer rate, an appropriate upper limit speed can be calculated.

Here, the effective transfer rate acquisition step includes an average transfer rate storage holding step of storing and holding the average transfer rate acquired by the average transfer rate acquisition means in a nonvolatile memory, and when the line printer is turned on, the effective transfer rate acquisition step includes In the transfer rate acquisition step, the average transfer rate stored and held in the nonvolatile memory in the average transfer rate storage holding step is acquired as an effective transfer rate. In this way, even if the line printer is turned off, the next time the power is turned on, the effective transfer rate acquisition means acquires the average transfer rate acquired so far as the effective transfer rate. Can do. Therefore, even when the power of the line printer is repeatedly turned on and off, the application installed in the external device to which the line printer is connected is specified, and the communication environment for connecting the external device and the line printer does not change. In this case, the effective transfer rate value can be converged.

  Here, it is possible to include a control command setting step of setting a control command indicating the separation based on a setting command from the external device. If the line printer is connected to a register device and the main issue is the issuance of accounting statements, for example, a cut command for cutting the recording paper with an auto cutter can be used as a control command that indicates a break. If it is set as, an effective transfer rate suitable for the application can be acquired, so that an appropriate upper limit speed can be calculated.

  It is preferable that the method further includes a step of determining whether to set the upper limit value based on a setting command from the external device. If the application installed in the external device to which the line printer is connected is specified and the communication environment connecting the external device and the line printer does not change, the upper limit speed will be set after the acquired effective transfer rate has converged. The upper limit speed calculated and stored in the calculation step is the fastest printing speed that can avoid the interruption of printing for each printing of one line of the line type print head in order to wait for reception of print data. Yes. Therefore, if a new upper limit value is not set after such upper limit speed is calculated and stored, thereafter, the upper limit speed stored up to the previous time is set as the upper limit value of the printing speed. The Therefore, after a certain period of use, the setting process of the upper limit value of the printing speed of the line printer can be reduced. In addition, when the upper limit speed is known in advance, if the known upper speed limit is stored, one line of the line type print head waits for reception of print data immediately after the line printer is installed. The printing can be prevented from being interrupted every time printing is performed, and the printing quality can be kept high.

  Here, when the upper limit value is not set, the line type print head may be driven at the maximum printing speed. With this setting, when it is not necessary to set the upper limit value of the printing speed of the line type print head, printing is performed at the maximum printing speed that the line printer originally has.

  In the present invention, the line type print head may be a line type thermal head. In the case of a thermal head, the print quality is significantly deteriorated due to the interruption of printing. Therefore, by adopting the present invention, such an adverse effect can be surely prevented.

  Next, the line printer of the present invention prints print data transmitted from an external apparatus by the above-described print control method.

According to the line printer and the print control method of the line printer of the present invention, the line printer itself acquires the effective transfer rate from the received print data, and the line printer itself sets the upper limit of the print speed based on the effective transfer rate. Set the value. Further, printing is performed by controlling the printing speed of the line type print head and the conveyance speed of the recording paper so that the printing speed is equal to or lower than the set upper limit value. Therefore, regardless of the communication speed between the host computer and the line printer and the processing efficiency of the application installed in the host computer, the printing speed of the line printer can be reduced when the effective transfer rate is low. As a result, it is possible to prevent printing from being interrupted every time one line of the line-type print head is waiting for reception of print data, resulting in fluctuations in the feeding amount of the recording paper and disturbing the print pitch. The printing quality can be kept high by avoiding the occurrence of uneven printing due to the change in printing density.

  Hereinafter, an embodiment of a line thermal printer to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an accounting processing system including a line thermal printer of this embodiment. FIG. 2 is a flowchart showing an operation of setting the printing speed based on the acquired effective transfer rate.

(Configuration of line thermal printer)
As shown in FIG. 1, the line thermal printer 1 of this embodiment is connected to a register device (host computer) 30, and on the roll paper (recording paper 4) based on the print data transmitted from the host computer 30, Coupons are printed. The line thermal printer 1 and the host computer 30 constitute an accounting processing system 40 that is set in the accounting counter of the store.

  The line thermal printer 1 receives print data transmitted from the host computer 30 via the communication interface 2. The received print data is temporarily stored in the reception buffer 6. The print data stored in the reception buffer 6 is instructed with character data and image data, a decoration command for designating the print position and size thereof, a discharge command for controlling the discharge of the recording paper 4, and a cut of the recording paper 4. Control commands such as cut commands are included. Therefore, the control unit 7 analyzes these control commands and generates print data for each line according to the print format by the line thermal head 8.

  The generated print data for each line is expanded and stored in the print buffer 9. In parallel with the development of the print data for each line in the print buffer 9, the print data for each line already developed and stored in the print buffer 9 is read into the latch circuit 10. . Then, the data is sent from the latch circuit 10 to the line thermal head 8, and printing is performed for each line.

  When printing for one line by the line thermal head 8 is completed, the stepping motor 11 drives the platen roller 12 to convey the recording paper 4 for one line. When the conveyance is finished, the line thermal head 8 performs printing for the next one line. These operations are repeated until the print data is completed. The printing speed by the line thermal head 8 and the conveyance speed of the recording paper 4 by the stepping motor are controlled by the drive control means 13 of the control unit 7.

  Here, the control unit 7 prints from the setting storage means 14 for storing the setting information, the transaction time from the detection of the control signal indicating the delimiter until the next detection of the control signal, and the print data received during that time. An average transfer rate acquisition unit 15 that acquires an average transfer rate from the amount of print data for each line developed in the buffer 9 and stores the average transfer rate in the setting storage unit 14, an effective transfer rate from the average transfer rate at a predetermined timing Effective transfer rate acquisition means 16 for acquiring the upper limit speed of the line thermal head 8 based on the acquired effective transfer rate, and stored in the setting storage means 14 and the upper limit speed calculation storage means 17 and stored in the setting storage means 14 The upper limit value setting means 18 for setting the set upper limit speed as the upper limit value is provided. The setting storage means 14 is composed of a nonvolatile memory (flash memory) that can retain the stored contents even when the power is turned off. When the upper limit value of the printing speed is set by the upper limit value setting means 18, the drive control means 13 drives the line thermal head 8 at a printing speed equal to or lower than the acquired upper limit value, and controls the stepping motor 11 to perform recording. The paper 4 is transported at a transport speed corresponding to the printing speed of the line thermal head 8.

  Also, a series of means (average transfer rate acquisition means 15, effective transfer rate acquisition means 16, upper limit speed calculation storage means 17, upper limit for acquiring the effective transfer rate and setting the upper limit value of the printing speed of the line thermal head 8 The value setting means 18) can set whether to enable or disable the operation according to an operation setting command from the host computer 30. Therefore, the control unit 7 includes operation setting detection means 19 for detecting whether or not the operation of the series of means is set to be effective. In addition, a print mode detection unit 20 is provided for detecting whether or not the print mode does not require reception of print data.

  Furthermore, the line thermal printer 1 includes an image storage unit 21 that stores graphic data such as store logo marks and advertisements that are routinely printed when a coupon is issued.

(Print speed setting operation)
Next, an operation in which the line thermal printer 1 sets the upper limit speed of the printing speed of the line thermal head 8 based on the effective transfer rate will be described with reference to FIG.

  When print data is transmitted from the host computer 30, in step ST1, the print mode detection unit 20 determines whether or not the print mode does not require waiting for reception of print data. For example, there are the following three cases where it is determined that the print data reception mode is not required.

  The first case is when the print mode is the page mode. In the page mode, printing is started after the print data received via the communication interface 2 is stored in the print buffer 9 until the break of the print data. Therefore, the print data is not changed between the start of printing and the break when printing ends. Does not require waiting for reception. That is, in the normal print mode, the print data for each line obtained by analyzing the print data is read into the latch circuit 10 in parallel with being developed and stored in the print buffer 9. Printing is performed. For this reason, when the printing speed of the line thermal head 8 is high, the read timing by the latch circuit 10 is earlier than the timing at which the print data for each line is developed into the print buffer 9, and the print data Waiting to receive is required. On the other hand, in the page mode, the print data for each line obtained by analyzing the print data is expanded and stored in the print buffer 9 until the break of the print data, and then read by the latch circuit 10. Since printing is performed, there is no need to wait for reception of print data from the start of printing until the end of printing.

  The page mode is set by a page mode command included in the print data transmitted from the host computer 30. Accordingly, when the control unit 7 detects a page mode command in the print data, the print mode is maintained in the page mode until a page mode cancel command for canceling the page mode command is detected. Examples of commands that indicate the separation of print data include a page break command, a recording paper 4 discharge command, and a cut command for cutting the recording paper 4 with an auto cutter. Data separation is determined.

  The second case is a case in which graphic data stored and held in advance in the image storage unit 21 is printed. The graphic data stored and held in the image storage unit 21 is printed by a graphic print command transmitted from the host computer 30.

When the graphic print command is detected in the print data, the control unit 7 generates print data for each line from the graphic data in the image storage unit 21. The generated print data for each line is developed and stored in the print buffer 9 until the end (separation) of the graphic data, and is then read and printed by the latch circuit 10. Therefore, there is no need to wait for reception of print data from the start of printing until the end of printing. Therefore, after the control unit 7 detects the graphic print command, this print mode is maintained until the printing of the graphic data is completed.

  The third case is a case where graphic data transmitted from the host computer 30 is designated and printed in this print mode. The transmitted graphic data is printed in the normal print mode. When a mode designation print command is transmitted from the host computer 30, the graphic data stored and held in advance in the image storage unit 21 is printed. Similarly, after being developed and stored in the print buffer 9 until the end of the graphic data (delimiter), it is read by the latch circuit 10 and printing is performed. Therefore, after the control unit 7 detects the mode designation print command, this print mode is maintained until the graphic data designated by the command is printed.

  If it is determined in step ST1 that the print mode does not require reception of print data, one line of the line thermal head 8 waits for reception of print data regardless of the detected effective transfer rate. There is no situation where printing is interrupted every minute. Therefore, without setting the upper limit speed of the printing speed of the line thermal head 8, the process jumps to step ST8 in which printing is performed at the maximum printing speed that the line thermal printer 1 originally has.

  If it is determined in step ST1 that the print mode requires the reception of print data, a series of means for acquiring the effective transfer rate and setting the upper limit value of the print speed of the line thermal head 8 The process proceeds to step ST2 for detecting whether or not the operations of the (average transfer rate acquisition means 15, effective transfer rate acquisition means 16, upper limit speed calculation storage means 17, and upper limit value setting means 18) are set to be valid.

  The validity / invalidity of the operation of the series of means for setting the upper limit value of the printing speed is set by the action setting command transmitted from the host computer 30, and the set validity / invalid status is stored in the setting storage means 14. Is retained. Accordingly, the operation setting detection unit 19 detects whether or not the operation of a series of units for setting the upper limit value of the printing speed is set from the status stored and held in the setting storage unit 14.

  In step ST2, when it is detected that the operation of a series of means for setting the upper limit value of the printing speed is set to be invalid, the upper limit stored and held in the setting storage means 14 at that time The process jumps to step ST7 in which the speed is set as the upper limit value of the printing speed of the line thermal head 8.

  If it is detected in step ST2 that the operation of a series of means for setting the upper limit value of the printing speed is set to be effective, the process proceeds to step ST3 for obtaining an average transfer rate.

  In step ST3, the average transfer rate acquisition unit 15 monitors the print data received via the communication interface 2 and the print data for each line developed in the print buffer 9 by the control unit 7, and the print data When a control command indicating a print data delimiter such as a cut command is detected, the transaction time is measured after the command until the next control command indicating the delimiter is received. In addition, the control unit 7 measures the data amount of print data for each line developed in the print buffer 9 from the print data received during the measured transaction time. Then, the data amount (transfer rate) of the print data for each line received per unit time is calculated from the measured transaction time and data amount. Since this transfer rate is calculated sequentially, an average of these is calculated and obtained as an average transfer rate. The acquired average transfer rate is stored in the setting storage unit 14.

  Which control command among the control commands indicating a break is adopted as a break for measuring the transaction time can be set in advance by a break setting command transmitted from the host computer 30. In the accounting processing system 40 of the present embodiment, the main use of the line thermal printer 1 is to issue accounting statements, and therefore, a cut command for cutting the recording paper 4 with an auto cutter is adopted as a control command indicating a delimiter.

  When the average transfer rate is acquired in step ST3, the process proceeds to step ST4 for acquiring the effective transfer rate from the acquired average transfer rate. In step ST4, the effective transfer rate acquisition unit 16 acquires the average transfer rate stored and held in the setting storage unit 14 as the effective transfer rate at a predetermined timing.

  The predetermined timing for acquiring a new effective transfer rate is the same as the timing at which the control unit 7 stores the maintenance information in the system area. When the power of the line line printer 1 is turned on, the average transfer rate stored and held in the setting storage unit 14 at that time is acquired as the effective transfer rate. The maintenance information is the accumulated operating time of the line thermal printer 1, the accumulated number of printed lines, and the like, and is information used for notifying the user or the like of a guideline for replacing worn parts.

  When the effective transfer rate is acquired in step ST4, the process proceeds to step ST5. In step ST5, the upper limit speed calculation storage means 17 calculates the highest print speed as the upper limit speed in the range where the print data is in time for each line of printing of the line thermal head 8 from the effective transfer rate, and sets this. Store in the storage means 14.

  When the specifications of the line thermal printer 1 of this embodiment are, for example, resolution 203 dpi, 64 digits / line, 24 dots / line feed, and a maximum printing speed of 300 mm / s, the upper limit speed calculation storage unit 17 acquires the acquired effective transfer rate. Is 57600 bps, 270 mm / s is calculated as the upper limit speed. If the acquired effective transfer rate is 38400 bps, 180 mm / s is calculated as the upper limit speed. If the acquired effective transfer rate is 9600 bps, 45 mm / s is calculated as the upper limit speed. Then, the calculated upper limit speed is stored in the setting storage unit 14.

  When the upper limit speed calculated in step ST5 is stored in the setting storage unit 14, the process proceeds to step ST6, where the upper limit value setting unit 18 sets the upper limit speed stored in the setting storage unit 14 to the line thermal head 8 Set as the upper limit of printing speed.

  When the upper limit value of the printing speed is set in step ST6, the process proceeds to step ST7, and the drive control means 13 drives the line thermal head 8 at a printing speed equal to or lower than the set upper limit value, and the stepping motor 11 is turned on. Under control, the recording paper 4 is transported at a transport speed corresponding to the printing speed of the line thermal head 8 to perform printing.

  Here, if it is detected in step ST2 that the operation of a series of means for setting the upper limit value of the printing speed is invalid, the upper limit of the printing speed is not passed through steps ST3 to ST5. The value setting operation proceeds to step ST6. In this case, the upper limit speed stored and held in the setting storage means 14 at the time of moving to step ST6 is set as the upper limit value of the printing speed of the line thermal head 8. Thereafter, the process proceeds to step ST7, and printing is performed at a printing speed equal to or lower than the set upper limit value.

As described above, the line thermal printer 1 according to this embodiment has the line thermal head 8 developed in the print buffer 9 per unit time from the print data transmitted from the host computer 30.
The amount of print data for each line according to the print format is acquired as an effective transfer rate (steps ST3 and ST4). Further, the upper limit value of the printing speed of the line thermal head 8 is set based on the acquired effective transfer rate (steps ST5 and ST6). Then, the drive control means 13 controls the printing speed of the line thermal head 8 and controls the conveyance speed of the recording paper 4 so that the printing speed is equal to or lower than the set upper limit value (step ST7).

  As a result, when the effective transfer rate of the print data is low regardless of the communication speed between the host computer 30 and the line thermal printer 1 and the processing efficiency of the application installed in the host computer 30, the line thermal printer 1 Since the printing speed is reduced by itself, it can be avoided that printing is interrupted for each printing of one line of the line thermal head 8 in order to wait for reception of printing data. Therefore, it is possible to keep the printing quality high by avoiding fluctuations in the feed amount of the recording paper 4 and disturbing the printing pitch, or changing the printing density and causing printing unevenness.

  Further, according to the line thermal printer 1 of the present embodiment, when a page mode command or a graphic print command is detected, it is possible to perform printing at the maximum printing speed regardless of the acquired effective transfer rate (steps). ST9).

  Further, the line thermal printer 1 of the present embodiment performs the operation of a series of means for setting an upper limit speed (average transfer rate acquisition means 15, effective transfer rate acquisition means 16, upper limit speed calculation storage means 17, upper limit value setting means 18). It can be invalidated by a function control command transmitted from the host computer 30.

  For example, like the accounting processing system 40 of this embodiment, the application installed in the host computer 30 is fixed, and the main use of the line thermal printer 1 is the accounting statement listing the purchased goods and their amounts. If the accounting processing system 40 is used for a certain period in the store, the effective transfer rate value acquired by the effective transfer rate acquisition means 16 converges. Accordingly, the upper limit speed value stored in the setting storage means 14 by the upper limit speed calculation storage means 17 converges. Therefore, if the operation of a series of means for setting the upper limit value of the printing speed is set to invalid after a certain period of time has elapsed after the accounting processing system 40 is installed, the upper limit value of the printing speed is set thereafter. The upper limit speed of the converged value stored and held in the setting storage means 14 in step ST6 can be set as the upper limit value of the printing speed without going through a series of operations (steps ST3 to ST5). In step ST7, printing can be performed at a printing speed that is equal to or lower than the set upper limit speed.

  In addition, a vendor who develops the accounting processing system 40 of this embodiment performs a usage test for a certain period in the same environment as the user's usage environment before delivering the accounting processing system 40 to the user, and after the upper limit speed has converged. If the operation of the series of means for setting the upper limit value of the printing speed is set to be invalid, the user can wait for one line of the line type print head from the time of installation of the accounting processing system 40 to wait for receiving print data. The printing can be prevented from being interrupted every time printing is performed, and the printing quality can be kept high. Further, even when the user does not need a function for setting the upper limit value of the printing speed, it can be dealt with by invalidating the operation of a series of means for setting the upper limit value of the printing speed. In this case, the initial value of the upper limit speed stored in the setting storage means may be the maximum printing speed originally provided in the line thermal printer.

Further, in the line thermal printer 1 according to the present embodiment, which control command is to be adopted as a control command indicating a data delimiter for measuring the transaction time can be set by a delimiter setting command. Therefore, if a control command that is delimited according to the application in which the line thermal printer 1 is used is selected, an appropriate effective transfer rate can be acquired.
The upper limit value of the printing speed of the line thermal head 8 can be set to an appropriate value.

  Although the print head of the line printer of this embodiment is a line type thermal head, the present invention can be applied to a line printer having a print head of another type.

  Further, the present invention can be applied to any communication interface 2 that connects the host computer 30 and the line thermal printer 1.

It is a schematic block diagram of the accounting processing system containing the line thermal printer to which this invention is applied. It is a flowchart which shows the operation | movement which sets a printing speed based on the acquired effective transfer rate.

Explanation of symbols

1. Line thermal printer 2. Communication interface 4. Recording paper 6. Receive buffer 7. Control unit 8. Line thermal head 9. Print buffer 10. Latch circuit 11. Stepping motor 12. Platen Roller, 13 · Drive control means, 14 · Setting storage means, 15 · Average transfer rate acquisition means, 16 · Effective transfer rate acquisition means, 17 · Upper limit speed calculation storage means, 18 · Upper limit setting means, 19 · Operation setting detection Means 20 · print mode detection means 21 · image storage unit 30 · host computer 40 · accounting system

Claims (10)

A print control method for a line printer that prints print data received from an external device line by line with a line-type print head,
The received print data is an amount of data to be developed in a print buffer for each line by the line type print head;
A reception time for receiving the print data;
An effective transfer rate acquisition step of acquiring as an effective transfer rate from,
Based on the effective transfer rate, the line printer calculates and stores the upper limit speed of the line-type print head so that a print interruption state for waiting to receive print data does not occur every time one line is printed. An upper speed calculation step;
An upper limit setting step for setting the upper limit speed as an upper limit of the printing speed;
A printing process in which the line-type print head is driven at a printing speed equal to or lower than a set upper limit value, and the recording medium is conveyed at a conveyance speed corresponding to the printing speed, and printing is performed;
A print control method for a line printer, comprising: In claim 1,
A print mode determination step for determining whether or not the print mode does not require reception of print data;
In the print mode determination step, when it is determined that the print mode does not need to wait for reception of print data, the maximum speed for driving the line type print head at the maximum print speed regardless of the effective transfer rate. A printing control method for a line printer, comprising a printing step. In claim 2,
The print mode that does not require waiting for reception of the print data includes a mode in which printing is started after the received print data is stored in the print buffer up to the end of the print data. Print control method. In any of claims 1 to 3,
The effective transfer rate acquisition step includes a reception step of receiving print data transmitted from the external device;
A transaction time measurement step of measuring a transaction time from when the control command indicating a break of print data is detected in the print data to the next reception of the same control command as the control command after the control command is detected. When,
A data amount measuring step of measuring a data amount of print data for each line developed in the print buffer from the print data received at the measured transaction time;
A transfer rate acquisition step of sequentially acquiring a transfer rate of print data from the measured transaction time and the measured data amount;
An average transfer rate obtaining step of obtaining an average transfer rate by averaging the transfer rates obtained sequentially,
A print control method for a line printer, wherein the average transfer rate is acquired as an effective transfer rate at a predetermined timing. In claim 4,
The effective transfer rate acquisition step includes an average transfer rate storage holding step of storing and holding the average transfer rate acquired by the average transfer rate acquisition means in a nonvolatile memory,
When the line printer is turned on, the effective transfer rate acquisition step acquires the average transfer rate stored and held in a nonvolatile memory in the average transfer rate storage hold step as an effective transfer rate. Print control method of the printer. In claim 4 or 5,
A line printer printing control method comprising a control command setting step of setting a control command indicating the separation based on a setting command from the external device. In any one of Claims 1 thru | or 6.
A line printer printing control method comprising a step of determining whether or not to set the upper limit value based on a setting command from the external device. In claim 7,
When the upper limit value is not set, the line type print head is driven at a maximum printing speed. The line printer printing control method according to claim 1, wherein the line printer is a line thermal printer.   A line printer that prints print data transmitted from an external apparatus by the print control method according to claim 1.

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