US 8,026,938 B2Granted

Thermal printer

AssigneeCitizen Holdings Co., Ltd.

InventorKenji Mito

Life of this patent

Estimating the term…

Loading patent…

Abstract

When printing is performed by dividing a thermal printer head into segmented blocks, the number of dots to be printed in one line is changed, depending on the case, high-speed printing with a small division number of the segmented blocks, or low-speed printing with a large division number of the segmented blocks. When the division number of the segmented blocks is large and printing is performed at a low speed, paper feeding within one line is performed by multiple pitches to prevent the paper sheet from halting in one line, and energization is performed for each pitch to prevent occurrence of gaps between dots and between lines, by increasing the number of dots to be printed in one line. In the multiple pitches in one line, the ratio of energization amount to be fed in each pitch is changed to reduce a difference in density among pitches in one line. Accordingly, when printing is performed by using segmented blocks of the thermal printer head, even though the division number of the segmented blocks is large and printing is performed at a low speed, printing without generating a gap between dots is possible.

Claims17

Dependent claims

A thermal printer comprising,

a thermal head enabled to be driven by segmenting multiple heating elements into one or multiple blocks according to a quantity of the heating elements to be driven, the heating elements being connected with one another in the form of a line and allowed to be energized simultaneously;
a paper carrier for feeding paper to the thermal head;
a power feeding section for feeding power into the heating elements of the thermal head, with respect to each of the blocks being segmented, and
a controller for controlling the paper carrier and the power feeding section, wherein,
without changing a width of one line in a paper feeding direction,
in response to one directive of power feeding for one line,
the controller forms multiple dots in the paper feeding direction in one line, in such a manner that the number of dots positively correlates with a division number corresponding to the number of the multiple blocks being segmented,
the paper carrier changes, with respect to each line, a dot pitch of the multiple dots in one line of a length in the paper feeding direction, in such a manner that a product of the quantity of dots and the dot pitch agrees with a width of one line in the paper feeding direction, and
the power feeding section feeds each of the dot pitch in one line, allowing an energization amount of a former dot pitch to be the same as or larger than the energization amount of a latter dot pitch.

6 more elements

A thermal printer comprising,

a thermal head enabled to be driven by segmenting multiple heating elements into one or multiple blocks according to a quantity of the heating elements to be driven, the heating elements being connected with one another in the form of a line and allowed to be energized simultaneously;
a paper carrier for feeding paper to the thermal head;
a power feeding section for feeding power into the heating elements of the thermal head, with respect to each of the blocks being segmented, and
a controller for controlling the paper carrier and the power feeding section, wherein,
without changing a width of one line in the paper feeding direction,
in response to one directive of power feeding for one line,
the controller compares the division number corresponding to the number of multiple blocks being segmented, with a preset value,
when the division number is smaller than the preset value, the paper feeding of one line is performed in one dot pitch, and one-time power feeding for one dot pitch is performed as to each of the blocks within one line,
when the division number is equal to or larger than the preset value, one line is divisionally driven and paper feeding is performed in multiple dot pitches, and
more than once power feeding is performed respectively for the multiple dot pitches as to each of the blocks in one line, and an energization amount for a former dot pitch is set to be equal or larger than the energization amount of a latter dot pitch.

7 more elements

Dependencies are inferred from the claim text.