JPH0710602B2 - Bar code printing control method for thermal printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention uses a line thermal head in which a plurality of heating elements are arranged in a straight line to print a barcode on a thermal printer. Regarding control method.

[Prior Art] Conventionally, in the printing of a bar code by a line thermal printer, it is general that a bar of a bar code is made to correspond to a dot to be printed, a black bar is a printed portion and a white bar is a non-printed portion. is there.

FIG. 3 is a block diagram showing an example of the configuration of the control circuit of the line thermal printer.

The microprocessor 1 includes a ROM 2 in which a print control program and bar code data are stored, a RAM 3 for temporarily storing the bar code data and the like, and a parallel bar code data read from the RAM 3 is replaced with serial data after thermal exchange. A parallel / serial exchange circuit 4 for supplying the head 5 and a feed motor driver 6 for driving a feed motor 7 for feeding a sheet are connected.

FIG. 4 shows a bar code diagram printed by the thermal printer and a vertical dot row corresponding thereto. The print control method will be described in detail below.

When the microprocessor 1 reads a program and bar code data required for printing control from the ROM 2, the bar code data is temporarily stored in the RAM 3, and the bar code data is read in parallel from the RAM 3 in response to a print request command. After the parallel data is converted into serial data by the parallel / serial conversion circuit 4, it is transferred to the thermal head 5 together with the synchronization clock pulse.

When the bar code data is transferred to the thermal head 5,
The heating element corresponding to the data generates heat and the dots of the first line are printed. After the printing is completed, the feed motor 7 is driven and the paper is fed so that the curved portion 8 of the dots of the first line and the dots of the second line is doubled.

Thereafter, the above operation is repeated from the first line to the sixth line to complete the barcode printing.

[Problems to be Solved by the Invention] A bar code to be printed, like the bar code shown in FIG. 4, has a bar arrangement direction orthogonal to the paper movement direction (hereinafter referred to as a vertical bar code). Code)),
There is a bar code (hereinafter referred to as a horizontal bar code) in which the arrangement direction of the bars is parallel to the moving direction of the paper.

In particular, when the former vertical bar code is printed, there are problems as described in detail below.

That is, since the bar code shown in FIG. 4 is composed of dots in two vertical columns, one bar is composed of the black bar 9 and the white bar 10.
Is also composed of dots in two vertical columns.

However, since the black bar 9 is the print dot portion, the curved portion 8 thereof extends beyond the area of the white bar 10, and the width of the white bar 10 becomes narrower by that amount, while the width of the black bar 9 becomes wider. Has become. Furthermore, when printing continuously, part of the thermal energy generated during the previous printing is accumulated in the heating element of the thermal head, and the accumulated energy is added to the next printing energy. The curved portion 8 is further expanded, and the difference in width between the black bar 9 and the white bar 10 is further increased.

That is, the width B of the actually printed black bar is wider than the original width A of the black bar assigned corresponding to the dot, and conversely, the actual width C of the white bar corresponds to the dot. The width D is narrower than the width D of the original white bar assigned.

Since the bar code in which the ratio of the black bar 9 and the white bar 10 is not uniform becomes unreadable as described above, conventionally, the speed at which the bar code is printed is slowed down, or the heating element of the thermal head is not used. Although the supply energy is controlled so that the supply energy becomes small, there is a drawback that the printing performance is deteriorated when the printing speed is slowed down. Also, if the supplied energy is controlled, the control circuit becomes complicated, and There are drawbacks such as poor print quality.

[Means for Solving the Problems] In order to solve the above-mentioned drawbacks, the present invention performs correction control so that the number of dots of a white bar whose width is narrower than that of a black bar is increased, and thereby the black bar and the white bar are An object of the present invention is to provide a barcode printing control method capable of printing a barcode having a uniform width.

[Operation] According to the barcode printing control method for the thermal printer of the present invention, when the vertical barcode is printed, the number of dots forming the white bar is corrected and controlled so as to be larger than the number of dots of the black bar. By increasing the width of the white bar, it is possible to print a barcode in which the widths of the black bar and the white bar are uniform.

[Examples] Hereinafter, the present invention will be described in detail based on Examples.

FIG. 1 is a flowchart showing a printing sequence in which printing is controlled by the barcode printing control method for a thermal printer of the present invention.

In Sequence 1, it is determined whether the barcode to be printed is a vertical barcode or a horizontal barcode. If the barcode to be printed is a vertical barcode, it is further determined in Sequence 2 whether it is a white bar or a black bar. .

When the bar code to be printed is a white bar, it is determined whether or not the correction flag for adding one print dot row is 1, and when the correction flag is not 1, the correction flag is set to 1 in sequence 4. Then, in sequence 5, the white bar flag is set. (In this case, if the correction flag = 1, dots are added, and if the correction flag = 0, they are not added.) If it is determined that the black bar is found in sequence 2, the correction flag is set to 0 in sequence 8. From the set of black bars.

In sequence 6, it is judged whether or not the vertical bar code setting is completed. If it is not completed, the process returns to sequence 2 to repeat the above operation.

When the setting of the vertical bar code is completed, the printing is performed in sequence 7.

On the other hand, if the horizontal bar code is determined in sequence 1, it is determined in step 9 whether or not it is a white bar. If the white bar is determined, the white bar flag is set in sequence 10 Sequence 12 if judged as bar
To set the black bar.

In sequence 11, it is determined whether or not the horizontal bar code setting is completed. If not completed, the process returns to sequence 9 to repeat the above operation.

When the setting of the horizontal bar code is completed, the printing is performed in sequence 7.

FIG. 2 shows a bar code printed by the bar code printing control method of the thermal printer of the present invention and a vertical dot row corresponding to the bar code.

In this case, the black bar 11 has two rows of dots, while the white bar 12 is corrected to have three rows of dots, so there is almost no difference in the width between the black bar 11 and the white bar 12, and they are almost the same. Become.

Therefore, it is possible to correct the width of the white bar 12 by a simple control of adding the number of dots of the print data, without performing the variable print speed and the control of the energy supplied to the heating element as in the conventional case. .

It should be noted that the dot row added when correcting the width of the white bar does not necessarily have to be one dot, and can be arbitrarily set by, for example, changing the shape of the heating element of the thermal head or the printing speed.

[Effect] As described above, according to the barcode printing control method for the thermal printer of the present invention, the width of the white bar, which is narrower than that of the black bar, is corrected. Therefore, the number of dots of the white bar is simply increased. With the control, there is an effect that it is possible to provide a barcode printing control method capable of high-quality barcode printing without deteriorating the printing performance.

[Brief description of drawings]

FIG. 1 is a flow chart showing a printing sequence in which printing is controlled by a bar code printing control method for a thermal printer of the present invention, and FIG. 2 is a vertical direction printed by a bar code printing control method for a thermal printer of the present invention. Directional bar code diagram and vertical dot row diagram corresponding to the bar code, FIG. 3 is a block diagram showing the configuration of the control circuit of the conventional thermal printer, and FIG. 4 is the bar code printing of the conventional thermal printer. FIG. 3 shows a vertical bar code diagram printed by the control method and a vertical dot array diagram corresponding to the bar code. FIG. 5 ...... Thermal head 7 ...... Feed motor 8 ...... Curved part 9, 11 ...... Black bar 10, 12 ...... White bar

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 3/20 115 C

Claims (1)

[Claims] 1. A storage unit for storing font data of a bar code, a thermal head for printing the bar code, a feed motor for conveying print paper, and a control unit for controlling these. In the provided thermal printer, a bar direction determining means for determining whether the barcode to be printed is a vertical barcode or a horizontal barcode, and a bar determination for determining whether the barcode bar is a white bar or a black bar. Means, and the bar direction determination means is determined to be a vertical bar code,
Further, when the bar code is judged to be a white bar by the bar judging means, a bar width correcting means for correcting the width of the white bar by adding dots is provided, and a thermal printer characterized by the above-mentioned. Bar code printing control method.