JP2010005970A - Printing apparatus, method of controlling printing apparatus, and a control program for printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent white striations from generating when printing image data and the like having a comparatively slow data transfer rate. <P>SOLUTION: A printing apparatus 10 for transferring a paper sheet with a paper sheet transferring motor 17 while printing data on the paper sheet with a thermal head 18 comprises: a control part 10A including a CPU 11, a motor controlling means 15 and a head controlling means 16 controlled by the CPU 11, and a printing data buffer 13B on which the printing data are extracted; and a driving part 10B including the paper sheet transferring motor 17 connected to the motor controlling means 15, and the thermal head 18 connected to the head controlling means 16, wherein the control part 10A supplies an electricity carrying electric power greater than a normal electricity carrying electric power to the thermal head 18 just before stopping transferring of the paper sheet by reducing a rate of the paper sheet transferring motor 17 in the case where the extraction process of next line printing data is not completed by the time printing is finished. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printing apparatus, a printing apparatus control method, and a printing apparatus control program, and more particularly to a technique for avoiding the occurrence of white stripes in a printed image.

  2. Description of the Related Art Conventionally, a thermal printing apparatus provided with a thermal print head is often used for printing labels and tags. The print head of this thermal printing apparatus is provided with a plurality of heating elements. This print head increases the temperature of the heating element by energizing the heating element, and transmits the heat of the heating element to the thermal paper by pressing the heating element against the thermal paper, or at a predetermined position on the paper via an ink ribbon. Printing is performed by a method such as transferring ink by pressing a heating element.

  Line thermal printers, one of the thermal printers, basically print dots on paper in batches using a plurality of heating elements arranged along the line direction perpendicular to the paper feed direction. It is something to do.

In such a thermal printing apparatus, as shown in FIG. 8, an acceleration period P for accelerating the paper feed motor at a constant rate, a constant speed period Q for reaching a predetermined speed and maintaining this speed, A series of printing is performed by the deceleration period R that decelerates at a constant rate after the constant speed period Q ends. The length of the constant speed period Q varies depending on the print data amount (see, for example, Patent Document 1).
JP-A-11-138872

  In the printing and paper feeding operations of the thermal printing apparatus as described above, printing of the print data of the first line (currently printing line) read from the print data buffer (for example, the buffer for two lines of print data) is performed. The second line (next line) of print data transmitted from the host computer is received and the expansion of the print data is terminated and stored in the second line (next line) buffer of the print data buffer. Thus, reception and expansion of print data and printing can be executed alternately and continuously.

  However, if the print data for the next line is not transmitted by the end of printing the line currently being printed, or if the development of the print data for the next line is not completed in time, printing of the line currently being printed is not completed. After the completion, the paper feeding and printing are temporarily stopped until the development of the print data of the next line is completed. That is, as shown in FIG. 9, after printing the line currently being printed in the acceleration period P1, the constant speed period Q1, and the deceleration period R1, the printing and paper feeding operations are temporarily stopped. Then, when the print data for the next line is transmitted or after the development of the print data for the next line is completed, paper feeding and printing are resumed, and printing of the next line (acceleration period P2, constant speed period Q2, deceleration period) R2) is performed. In order to prevent dot crushing in the first printing of the next line when paper feeding is resumed, feeding may be performed from one dot of paper in the stop period A.

In this way, when starting to print the next line, when feeding from one dot of paper, or when there is deformation of the platen by the thermal head being pressed, the line currently being printed and the next line are When the image data is continuous, white streaks as shown in FIG. 10 occur (FIG. 10 is an example of printing solid black image data for the sake of clarity).
When printing image data that has a large amount of data and takes a long time to transfer, the above-mentioned printing and paper feeding operations are likely to stop, such as waiting for communication data and processing not being in time, and the above-mentioned white stripes are easily noticeable. Since it is an image, the print quality is likely to deteriorate.

  The present invention has been made in view of such circumstances, and a printing apparatus, a printing apparatus control method, and a printing apparatus capable of preventing the occurrence of white stripes when printing image data or the like that takes time to transfer data. It is an object to provide a control program printing apparatus.

In order to achieve the above object, a printing apparatus according to the present invention is a printing apparatus that feeds the paper by a paper feed motor while printing data on the paper by a thermal head,
A control unit including motor control means for controlling the paper feed motor and head control means for controlling the thermal head;
With
The control unit supplies power larger than before to the thermal head before stopping the paper feed motor.
Further, the controller supplies the large electric power at least one dot line immediately before stopping the paper feed motor.
The control unit stops the paper feed motor when it is determined that there is no data to be printed next or that the processing of data to be printed next is not in time.
According to the above configuration, when there is no next print data, or when the development process is not completed and the process is not in time, the paper feed motor is decelerated to at least one dot line immediately before the paper feed is stopped. A power larger than the power applied before the one dot line is supplied to the thermal head. As a result, the print density of the dot line before the paper feed motor stops increases. In particular, white streaks are generated during printing even for image data, etc., where it takes time to transfer data, making it impossible to prepare the next print data, or the amount of print data is too large to be processed in time, and print quality is likely to deteriorate. Can be prevented.
Preferably, before the paper feed motor is stopped, the energizing time for the thermal head is set longer than the energizing time for obtaining dots of the previous print density before the paper feeding is stopped. It is characterized in that electric power larger than electric power for obtaining dots of normal printing density is supplied to the thermal head.
As described above, by setting the energization time for the thermal head before the paper feed motor stops longer than the energization time for obtaining normal print density dots, the diameter of the print dots expands to blur. Since printing dots having a density capable of filling in white stripes are printed, it is possible to prevent white stripes from occurring when printing image data or the like.
Preferably, before the paper feed motor is stopped, the voltage applied to the thermal head is set higher than the voltage for obtaining a dot having a normal printing density, so that the paper feed is stopped before the paper feed motor is stopped. It is characterized in that electric power larger than electric power for obtaining dots of normal printing density is supplied to the thermal head.
As described above, by setting the voltage applied to the thermal head before the paper feed motor stops to be higher than the voltage for obtaining a normal density print dot, the diameter of the print dot expands so as to bleed. Since printing dots having a density that can fill in the white stripes are printed, it is possible to prevent the occurrence of white stripes when printing image data or the like.

A control method for a printing apparatus according to the present invention is a control method for a printing apparatus that feeds the paper by a paper feed motor while printing the print data on the paper by a thermal head.
A development determination step for determining whether there is no data to be printed next during printing or whether processing of data to be printed next is not in time;
In the development determination step, when it is determined that there is no data to be printed next or the processing of the data to be printed next is not in time, before stopping the paper feed motor, a larger power than before is supplied. Supplying the thermal head immediately before,
It is characterized by including.
If it is determined by the above control method that there is no next print data in the print data buffer, or the processing is not in time because it is not expanded in the print data buffer, the thermal head is stopped before the paper feed motor stops. The power supplied to is greater than the power previously applied. By stopping the paper feed motor after printing in this way, the density of the print dots in the line immediately before the paper feed motor stops increases, and the print dots are blurred so that the print is greatly printed. White streaks can be prevented during printing.
According to another aspect of the present invention, there is provided a printing apparatus control program that causes a control unit mounted on a printing apparatus to execute each step of the printing apparatus control method.
This prevents the occurrence of white streaks when printing image data or the like only by changing the firmware, which is a control program executed by the control unit of the printing apparatus, without requiring changes to applications on the host computer side. be able to.

  Preferred embodiments of a printing apparatus, a printing apparatus control method, and a printing apparatus control program according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a thermal printing apparatus 10 that is a printing apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, a printing apparatus 10 is a thermal printing apparatus and a line printer capable of printing for each dot line, and controls input / output of data and operation of each unit of the driving unit. And a drive unit 10B including a paper feed mechanism, a print head, and a drive mechanism thereof.

  The control unit 10A includes a CPU 11, a ROM 12, a RAM 13A and a print data buffer 13B connected to the CPU 11, an input / output circuit 14 connected to the CPU 11, a motor control means 15 and a head control connected to the input / output circuit 14. Means 16.

  On the other hand, the drive unit 10 </ b> B includes a paper feed motor 17 including a stepping motor connected to the motor control unit 15, and a thermal head 18 connected to the head control unit 16. Note that the print data buffer 13B can store at least two lines of print data.

  The thermal head 18 is connected to the tip of a flexible wiring board (not shown) attached to the head driving IC, for example, and prints a large number of heating elements (for example, horizontal 500 × vertical 1 dot) arranged along the printing line. This is a line printer head provided with a heating element (not shown).

  As shown in FIG. 7, the printing apparatus 10 according to the present embodiment basically reaches the acceleration period P for accelerating the paper feed motor 17 at a constant rate and reaches a predetermined speed. A series of printing is performed by the constant speed period Q for maintaining the speed and the deceleration period R for decelerating at a constant rate after the constant speed period Q ends.

  A control method of the printing apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 2 is an explanatory diagram showing an example of speed control of the paper feed motor 17 in the present embodiment.

  As shown in FIG. 2, by the time the printing of the line currently being printed is completed, the print data of the next line has not been received and has not been prepared, or the development of the print data of the next line has not been completed in time. If not, the paper feeding and printing are temporarily stopped after the printing is completed until the reception and development of the print data of the next line is completed.

  That is, as shown in FIG. 2, after printing is performed in the acceleration period P1, the constant speed period Q1, and the deceleration period R1, the printing and paper feeding operations are temporarily stopped.

  After the development of the print data for the next line is completed, paper feeding and printing are resumed, and the next line is printed (acceleration period P2, constant speed period Q2, and deceleration period R2). Then, in order to prevent dot crushing due to printing of the next line when the paper feed is resumed, the paper is fed from the paper for one dot in the stop period A.

  FIG. 3 shows pulses of energization voltage applied to the thermal head 18 immediately before time t when the paper feed motor 17 stops in the deceleration period R1 in FIG. In FIG. 3, in order to obtain the normal print density (print density at which bleeding does not occur), the thermal head of the line immediately before entering the stop period A (immediately before the paper feed motor 17 is stopped) is obtained. It is assumed that a pulse of energizing voltage V1 and energizing time T1 is given to 18.

On the other hand, in the present embodiment, in order to prevent white streaks caused by feeding from one dot of paper in the stop period A, the line immediately before the paper feed motor 17 stops in the deceleration period R1. By making the density of the printing dots higher than usual, the diameter of the printing dots is enlarged so as to bleed in the paper feed direction, and white stripes are filled.
FIG. 4 is a diagram for explaining an example of a method for controlling the energization power to the thermal head 18 in the present embodiment. FIG. 5 is a diagram for explaining another example of a method for controlling the energization power to the thermal head 18 in the present embodiment. FIG.

  In the deceleration period R1, the energization power to the thermal head 18 necessary to obtain a normal density print dot (circular dot without blur) is the energization voltage V1 and the energization time T1, as shown in FIG. Then, in the present embodiment, as shown in FIG. 4, the energization time T2 immediately before the time t when the paper feed motor 17 stops is set to be longer than the energization time T1 for obtaining the normal print density dots shown in FIG. By setting it long (for example, T2 is set to 1.5 times T1), the print dot diameter is enlarged so as to bleed and print dots having a density capable of filling white stripes are printed. Here, one dot line is used, but several dot lines may be used in order to fill white stripes.

  Alternatively, as shown in FIG. 5, the energization voltage V2 immediately before the time t when the paper feed motor 17 stops is set higher than the energization voltage V1 for obtaining the normal density print dots shown in FIG. V2 is 1.5 times V1). Or you may set so that an electric current may become large. Here, one dot line is used, but several dot lines may be used in order to fill white stripes.

  Alternatively, a combination of time, voltage, and current is appropriately changed to obtain a print dot having a density at which the energization power applied to the thermal head 18 immediately before time t when the paper feed motor 17 stops can fill white stripes. You may make it become energized power.

  Next, the procedure of the control method of the printing apparatus 10 according to the present embodiment will be described with reference to FIG. 6 and the above-described FIGS. FIG. 6 is a flowchart showing a control procedure of the paper feed motor 17 in the printing apparatus 10 according to the present embodiment.

  When the operation of the printing apparatus 10 is started by turning on the power or the like, the CPU 11 performs operation confirmation of the control unit 10A and the drive unit 10B and performs initialization. Next, the print data transmitted from the host computer is received, and the print data is processed to generate a print image such as a dot pattern, which is developed in the print data buffer 13B.

  The CPU 11 reads one line of print data (first line print data) from the first storage area of the print data buffer 13B. The paper feed motor 17 is accelerated by the motor control means 15 (acceleration period P1 in FIG. 2) and energization of the thermal head 18 is started by the head control means 15 to start printing the first line (step S1). ).

  When the paper feed motor 17 reaches a predetermined speed, the constant speed period Q1 starts, and printing is performed at a constant speed (step S2). Then, the CPU 11 determines whether or not the print data of the second line (next line) is expanded in the second storage area of the print data buffer 13B before the constant speed printing of the first line is completed (step S1). S3).

  If it is determined that the print data of the second line (next line) exists in the print data buffer 13B and has already been developed before the constant speed printing of the first line is completed, the CPU 11 performs motor control. The paper feeding motor 17 is rotated at a constant speed with respect to the means 15 to print the second line (next line) of print data at a constant speed (step S4).

  Then, it is determined whether or not the print data is the last line data (step S5). If the print data is not the last line data (step S5: No), the process returns to step S3 to continue the printing operation. On the other hand, when it is the data of the last line (step S5: Yes), the paper feed motor 17 is decelerated (step S6), the paper feed motor 17 is stopped (step S7), and printing of all the lines is completed. .

  On the other hand, if it is determined in step S3 that the print data of the second line (next line) has not yet been developed in the print data buffer 13B, the paper feed motor 17 is decelerated (step S8), and the paper feed motor is Immediately before the time t when 17 is stopped, as shown in FIG. 4 or FIG. 5, printing is performed such that the power to the thermal head 18 becomes larger than the power to obtain the previous normal printing density dots (step S9). Then, the paper feed motor 17 is stopped (step S10).

  Then, it is determined whether or not the print data is the data of the last line (step S11). If the print data is the data of the last line (step S11: Yes), the printing is finished. If it is not the data of the last line (step S11: No), it waits for the next line of print data to be expanded in the print data buffer 13B (step S12). Returning to S1, the paper feed motor 17 is accelerated to print the next line.

  As described above in detail, according to the control method of the printing apparatus 10 according to the present embodiment, just before the time t when the paper feed motor 17 stops, a dot having a normal print density is applied to the thermal head 18. Since energizing power larger than the energizing power to be obtained is supplied, the density of the printed dots on the line immediately before entering the stop period A is increased, and printing is performed so that the printed dots are blurred. Thus, no white streak occurs between the next line (in order to show the effect in an easy-to-understand manner, this is an example of printing solid black image data).

  The above-described control method of the printing apparatus 10 according to the present embodiment can be realized by firmware that is a control program executed by the CPU 11 of the printing apparatus 10. For this reason, it is not necessary to change the application on the host computer side, and can be realized only by changing the firmware that is a control program executed by the CPU 11 of the printing apparatus 10.

  As described above, according to the printing apparatus, the printing apparatus control method, and the printing apparatus control program according to the present embodiment, white streaks are prevented when printing image data having a relatively low data transfer speed. Therefore, the quality, appearance, and design of image printing can be maintained well.

1 is a block diagram illustrating a printing apparatus according to an embodiment. In the speed control example of the paper feed motor according to the present embodiment, it is an explanatory diagram showing a case where the development of the print data of the next line is not completed before the printing of the line currently being printed is completed. FIG. 3 is a diagram showing energized voltage pulses for several steps before time t when the paper feed motor stops in the deceleration period R1 in FIG. It is a figure explaining an example of the control method of the energization power to the thermal head in this Embodiment. It is a figure explaining another example of the control method of the energization power to the thermal head in this Embodiment. It is a flowchart which shows the control procedure of the paper feed motor by this Embodiment. It is explanatory drawing which shows the printing result by this Embodiment. It is explanatory drawing which shows the example of speed control of the conventional paper feeding motor. In the conventional speed control of the paper feed motor, it is an explanatory diagram showing a case where the development of the print data of the next line is not completed before the printing of the line currently being printed is completed. It is explanatory drawing which shows generation | occurrence | production of a white stripe by the conventional printing result.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 10A ... Control part, 10B ... Drive part, 11 ... CPU, 12 ... ROM, 13A ... RAM, 13B ... Print data buffer, 14 ... Input / output means, 15 ... Motor control means, 16 ... Head control means 17 ... paper feed motor, 18 ... thermal head

Claims (7)

A printing apparatus that feeds the paper by a paper feed motor while printing the print data on the paper by a thermal head,
A control unit including motor control means for controlling the paper feed motor and head control means for controlling the thermal head;
With
The control unit supplies a larger electric power to the thermal head than before before stopping the paper feed motor.   The printing apparatus according to claim 1, wherein the controller supplies the large electric power at least for one dot line immediately before stopping the paper feed motor.   2. The control unit according to claim 1, wherein the control unit stops the paper feed motor when it is determined that there is no data to be printed next or that processing of data to be printed next is not in time. The printing apparatus as described.   The printing apparatus according to claim 1, wherein the large electric power supplied by the control unit is longer than a previously applied energization time.   The printing apparatus according to claim 1, wherein the large electric power supplied by the control unit is higher than a previously applied voltage. A control method of a printing apparatus that feeds the paper by a paper feed motor while printing the print data on the paper by a thermal head,
A development determination step for determining whether there is no data to be printed next during printing or whether processing of data to be printed next is not in time;
In the development determination step, when it is determined that there is no data to be printed next or the processing of the data to be printed next is not in time, before stopping the paper feed motor, a larger power than before is supplied. Supplying the thermal head;
A control method for a printing apparatus.   A control program for a printing apparatus, which causes a control unit mounted on the printing apparatus to execute each step recited in claim 6.

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