US 6,747,683 B2 · Thermal head control method and control apparatus

Abstract

A control method and apparatus for a thermal head capable of printing two colors applies thermal history control using a simple circuit configuration. The thermal head control apparatus has a print data processing unit 40 and a drive control circuit 50. The print data processing unit 40 has a first command processing function for converting first color data to a first and second stage energizing commands, a second command processing function for converting second color data to a second stage energizing command, a first line buffer 43 for storing first stage energizing commands, and a second line buffer 44 for recording second stage energizing commands. The print data processing unit 40 selectively outputs energizing commands from the first line buffer 43 and energizing commands from the second line buffer 44. The drive control circuit 50 has a print buffer 52 and history buffer 53, and energizes the heating elements of the thermal head 10 based on energizing commands determined by a comparison of content stored to the print buffer 52 and history buffer 53.

Claims15

Dependent claims

A thermal head control method for controlling different heat output levels by changing the amount of energizing applied to heating elements of a thermal head, comprising the steps of:

(a) energizing the heating elements in a first energizing stage and in a second energizing stage to produce a first color at a first heat output level;
and
(b) providing a pause of predetermined duration between the first energizing stage and the second energizing stage.

A thermal head control apparatus for controlling heat output from heating elements of the thermal head by changing the amount of energizing applied to each heating element in a thermal head having an array of multiple, independently drivable, heating elements, comprising:

a print data processing unit for processing a print data group that is information relating to the production of color at a specific heating element according to different heat output levels and contains both or either first color data based on a first heat output level and second color data based on a second heat output level lower than the first heat output level, the print data processing unit having:
a first command processing function for converting first color data to a first stage energizing command and a second stage energizing command,
a second command processing function for converting second color data to the second stage energizing command,
a first memory area for storing the first stage energizing command, and
a second memory area for recording the second stage energizing command, and
a selector for selectively outputting energizing commands from the first memory area and energizing commands from the second memory area;
and
a drive control circuit having a first command storage area for storing energizing commands contained in the first memory area or second memory area, and a second command storage area for storing energizing commands contained in the first command storage area, and energizing a specific heating element by means of a energizing command based on a comparison between the first command storage area and second command storage area.

5 more elements

Dependencies are inferred from the claim text.

Thermal head control method and control apparatus

Life of this patent

Thermal head control method and control apparatus

Life of this patent

Abstract

Claims15