JPS6151358A - Graphic printing method of thermal printer - Google Patents

Abstract

PURPOSE:To prevent the generation of image omission at a solid print part, by performing printing by using elements, of which the number is more than that of the elements corresponding to the feed movement amount of one line toward both end sides. CONSTITUTION:The elements 1 of a thermal head enable 24-dot printing and each interval dimension between dots is 1/144'' and the whole width of said dots is 1/6'' and a feed amount is also 1/6''. When a graphic printing mode is taken, the feed amount comes to 8/72'' and 8-dot printing displaying D0-D7 is performed. At this time, 8 elements from No.4-No.8 of the elements 1 are used and 6 dots of D1-D6 are constituted of two elements, and D0 and D7 are constituted of three elements. Therefore, a printing length is 9/72''. In this constitution, when solid printing is performed, printing is performed with the feed amount of 8/72'' but the printing length at this time is larger than the feed amount and, as a result, the printing width of one line exceeds the feed amount and, therefore, no image omission between lines is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to graphic printing using a thermal printer that prints graphics using a thermal head.

2. Description of the Related Art In general, some thermal printers have a thermal head having 24 dots of heating elements, that is, elements, in order to perform high-quality printing. The spacing between each element is 1/144', and the width of all elements is 176''.The area used when printing normal characters is 15 dots from the top.
The lower nine dots are used for underlining and other purposes. There is a special specification for graphic printing using all the elements in such a thermal head, but such a specification is not common at present due to the influence of the arc of the platen, and some The standard specification is to print graphics using elements.

For example, feed Rat. 16 out of 24 dots are used as /72'. Furthermore, one dot is composed of two elements, and graphic printing is performed using eight dots.

Problems to be Solved by the Invention In graphic printing, unlike normal character printing, so-called solid printing is often performed. In this case, printing by the elements at both ends when printing the - line is not sufficient, resulting in white spots between the lines. therefore,
There is a problem that the finish of solid printed areas is not good.

An object of the present invention is to prevent white spots from occurring in solid printed areas.

Means for Solving the Problems The present invention uses a thermal head consisting of a large number of elements. When performing graphic printing with some of the elements, printing is performed using more elements on both ends than the feed amount. As a result, the amount of heat generated at both ends of the - line is sufficient, thereby ensuring printing at both ends and preventing white spots from occurring during solid printing.

In other words, since the number of elements on both end sides is large, the amount of heat generated at the ends is greater than that at the center, thereby ensuring reliable printing over the entire width of the feed amount.

Embodiment First, the heating element of the thermal head, that is, element 1 is numbered 24 as shown with numbers 1 to 24.
It is possible to print dots.

The spacing between each element 1 is 1/144', the total width is 176', and the feed amount is also 1/6'.
It is. Then, when it comes to graphic printing mode,
The feed amount is 8/72", and 8 dots are printed as indicated by D. to D7. At this time, 18 elements from No. 4 to No. 21 are used as element 1. Moreover, , D: 6 dots from I to D6 are composed of 2 elements, and Do and D7 are composed of 3 elements. That is, the number of elements at the end is large. Therefore, the feed amount is 8/72'. However, the print length is 9/72'.

In such a configuration, when performing solid printing etc.
Printing is performed with a feed amount of 772", but the print length at that time is 9772" as described above, so it is larger than the feed amount. As a result, the width of the - line printing exceeds the feed amount, so the line spacing is There will be no white spots.

Furthermore, in the case of graphic printing, since the center of the element 1 of the thermal head is used, the state of contact with the platen is constant throughout, and the printing state over the entire width is stable.

Effects of the Invention The present invention performs graphic printing using some of the many elements of the thermal head as described above, and since the printing is performed using more elements than the amount of movement of the feed, - The edges of line printing are reliably printed, thereby preventing white spots between lines.Furthermore, since the center part of the element is used when printing graphics, there is no uneven contact with the platen. It is not affected by the arc of the platen.

[Brief explanation of drawings]

The drawing is an explanatory diagram showing the arrangement of elements of a thermal printer and the combination state at the time of graphic printing. 1...Element

Claims (1)

[Claims] 1. In a device in which graphic printing is performed using a smaller number of elements than the number of elements provided in the thermal head, the number of elements is smaller than the number of elements corresponding to the amount of movement of one line of feed. A graphic printing method for a thermal printer, characterized in that printing is performed using more elements toward both ends. 2. In a device that performs graphic printing using a smaller number of elements than the number of elements provided in the thermal head, the number of elements that correspond to the amount of movement of one line of feed is larger than the number of elements toward both ends. A graphic printing method for a thermal printer, characterized in that printing is performed using a large number of elements, and graphic printing is performed by selecting an element in the center of the thermal head.