JPS6345072A - Bar code printing by thermal head - Google Patents

Abstract

PURPOSE:To form a bar code consisting of small-width and large-width bars having widths conforming to specifications in the state of being free of black or the like, by setting a paper feed quantity for each line to a predetermined value so that printing by heat generating elements is conducted with a predetermined overlap length provided for each line in a paper-feeding direction, in a serial-type bar code printing method. CONSTITUTION:Printing by heat generating elements 4 is conducted with a predetermined overlap length l=65mum provided for each line in a paper-feeding direction. Fig. (a) illustrates a printing operation for each line, for the leftmost heat generating element 4 of a thermal head 5. The printing is so conducted that the width W1 of a small-width black bar 7 formed by printing a series of 2 dots is 0.375mum, the width W2 of a large-width black bar 8 formed by printing a series of dots is 1.1250mum, the width W3 of a small-width white bar 9 formed by not printing a series of 3 dots is 0.400mum, and the width W4 of a large-width white bar 10 formed by not printing a series of 8 dots is 1.175mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bar code printing method using a thermal head.

2. Description of the Related Art In recent years, barcodes have been used in various fields for posi sales of various products. A line-type thermal head is often used to print such barcodes. Here, when using such a thermal head, as shown in Fig. 2 (
As shown in a), a so-called parallel printing method in which the arrangement direction of the plurality of heating elements 2 of the thermal head 1 and the line direction of the barcode 3 are perpendicular to each other is common. According to this, the barcode standard is determined by the physical dimensions such as the dimensions and pitch of each heating element 2, so it is possible to print a barcode 3 that meets the standard relatively easily. Generally known barcode formats such as 3 of 9, N W 7, INT 2 of 5, etc. are formed by a combination of black rope bars and black bars in the printed part, and white bars and thick white bars in the non-printed part. configured. Among these, basically, the width dimensions of the thin bars are set to be equal, and the width dimensions of the thick bars are set to be equal. Further, the width ratio between the thin bar and the thick bar is set to a constant ratio, for example, 1:3.

Problems to be Solved by the Invention However, some devices do not print barcodes as shown in Figure 2 (b).
), it is necessary to use a so-called serial printing method in which printing is performed in a positional relationship in which the arrangement direction of the heating elements 2 and the line direction of the barcode 3 are parallel. Such a serial printing method is generally not possible unless the heating element has a square shape, and the shape of the heating element is limited. Also, in the case of serial printing method,
Since this is different from the parallel printing method by 90 degrees, it is not possible to perform printing that satisfies the above-mentioned barcode format standards by simply controlling the rotation by 90 degrees with respect to the parallel printing method.

Means for Solving the Problems In a serial barcode printing method, a barcode is printed on a sheet of paper using a thermal head formed by linearly arranging a plurality of heating elements, the barcode being parallel to the direction in which the heating elements are arranged.
The paper feed amount for each line is set to a predetermined value, and printing is performed while providing a predetermined overlap length for each line in the paper feed direction of the heating element.

When printing barcodes using the serial method, the paper feed amount is set to a predetermined value in relation to the dimensions of the heating element of the thermal head, and the heating element prints while repeating overlaps for each line, so it meets the standard. A barcode with a narrow bar is formed without any blank areas.

Example An embodiment of the present invention will be described based on FIG.

First, a thermal head 5 is provided, which is formed by arranging a plurality of heat generating elements 4 in a linear manner. Here, the heating element 4 is formed in a rectangular shape, and the long side a=2201 m,
The short side b is 120 cm, the pitch p is 1311i+, and the density is 7.6 dots/M. Therefore, in this embodiment, the bar code 6 of 3 of 9, that is, the width ratio of the thin bar to the thick bar is 1=3, is printed by a serial method, and in this case, the paper feed amount P for each line is Considering the dimensional relationship of the heating element 4 described above, P=1551m
It is set to print. The black line bar 7 in the printed area is 2 dots printed on the heating element 4, the black bar 8 is 7 dots printed on the heating element 4, the white bar 9 in the non-printed area is 3 dots printed on the heating element 4, and the thick white bar is 2 dots printed on the heating element 4. 10 is for allocating 8 dots of the heating element 4.

According to such a printing method, the heating element 4 has a predetermined overlap length Q==65α for each line in the paper feeding direction.
You will print while holding m.

FIG. 1(a) shows the leftmost heating element 4 of the thermal head 5.
The following is an example of the printing operation for each line. In the figure, the position of each line is slightly shifted to avoid overlapping and to make the movement clearer.
In reality, they are located on the same line. This results in 2
Width W of black line bar 7 due to dot printing = 0. 3
75.1m, width W2 of black bar 8 with 7 dot printing =
1. 1250 zm, width W of white set bar 9 with 3 dots unprinted, =O.

4004m, width W of white bar 10 with 8 dots unprinted
4=1. Each is printed as 1751+111.

As a result, the bar code 6 can be printed in a state where the ratio of each rope bar 7.9 to the thick bars 8, 10 is in the following relationship.

Black line bar: black bar 1:3.067 Black thin bar/white thick bar = 1:3. i33 White rope bar: Black bar = l: 2,875 White silk bar: White thick bar = 1.2.938 In other words, it is a bar code serial within the standard that can cover the bar ratio clearance and the navy blue bar clearance of 7°9. It can be printed using this method. In particular, since this embodiment uses a thermal head 5 with a rectangular heating element 4, serial printing can be performed at a faster printing speed than a serial printing method using a square heating element, and each dot in the printed area can be Since the spaces overlap, Yamanaka liquid does not cause any inconvenience such as printing.

The advantages and disadvantages of the invention are that, as mentioned above, the paper feed amount for each line is set to a predetermined value in relation to the dimensions of the heating element of the thermal head, so that the heating element has an overlapping portion for each line. Therefore, it is possible to print a bar code with a ratio of thin bars to thick bars that meets the specifications without using Yamanaka liquid.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a printing operation according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a general parallel/serial printing system.

Claims (1)

[Claims] In a serial barcode printing method that prints a barcode parallel to the heating element arrangement direction on paper using a thermal head formed by linearly arranging a plurality of heating elements, the paper feed amount for each line is set to a predetermined value. A barcode printing method using a thermal head, characterized in that printing is performed while setting a predetermined overlap length for each line in the sheet feeding direction of the heating element.