Thermal printer

• US 4,415,908 A
• Filed: 07/02/1982
• Issued: 11/15/1983
• Est. Priority Date: 06/13/1980
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sugiura, Kenitiro
• Primary Examiner(s): Hartary, Joseph W.
• Application Number:
  US06/394,790
• Time in Patent Office: 501 Days
• Field of Search: 346/76 PH, 219/216, 400/120
• US Class Current: 347/190
• CPC Class Codes: B41J 2/36 Print density control

Abstract

There is disclosed a thermal printer constructed with a thermal head having a plurality of heat generating sections to record a pattern on a recording sheet; a pattern memory to record pattern information for selectively driving said plurality of heat generating sections in said thermal head; an adjusting pattern device connected to the pattern memory to discriminate the pattern informations for selective driving of at least three adjacent heat generating sections out of the plurality of heat generating sections in the thermal head, and to generate adjusting pattern information which drives two heat generating sections out of the three heat generating sections; and a feeding device connected to the pattern memory and the adjusting pattern device, to feed the pattern information stored in the pattern memory and the adjusting pattern information to the thermal head.

Claims

1. Thermal printer comprising:

(a) a thermal head having a plurality of heat generating sections to record a pattern on a recording sheet;

(b) a pattern memory for recording pattern information to selectively drive said plurality of heat generating sections in said thermal head;

(c) adjusting means connected to said pattern memory, to discriminate said pattern informations for selectively driving at least three adjacent heat generating sections out of said plurality of heat generating sections in said thermal head, and to generate adjusting pattern information which drive two heat generating sections out of said three heat generating sections; and

(d) means connected to said memory and said adjusting pattern means for supplying said pattern information stored in said pattern memory and said adjusting pattern informations to said thermal head.

2. Thermal printer as set forth in claim 1, wherein said supplying means supplies to said thermal head said adjusting pattern information of said pattern memory and said adjusting information of said adjusting pattern means with a separate timing.

3. Thermal printer as set forth in claim 1, wherein said adjusting pattern means includes a first memory for storing therein said pattern information as memorized in said pattern memory in the form of its having been shifted rightward by one bit, and a second memory for storing therein said pattern information of said pattern memory in the form of its having been shifted leftward by one bit.

4. Thermal printer as set forth in claim 1, wherein said thermal head has a plurality of heat generating sections arranged in one line.

5. Thermal printer comprising:

a thermal head having a printing part of at least n numbers of dots in a row;

adjusting means for driving said thermal head and for generating a heat generating signal for row adjustment, at least once, to adjust a density difference in the row in accordance with row dot pattern data to be printed; and

supplying means for supplying to said thermal said heat generating signal for row adjustment and the row dot pattern data to said thermal head.

6. Thermal printer as set forth in claim 5, wherein said supplying means further comprises means for applying at separate times said heat generating signal for row adjustment and the row dot pattern data.

7. Thermal printer as set forth in claim 5, further comprising:

row adjustment means for generating a heat generating signal for row adjustment, at least once, relative to the row dot pattern data to adjust the density difference in adjacent rows upon comparison of the row dot pattern data with the preceding row dot pattern data, and in addition to said heat generating signal for row adjustment; and

means for applying said heat generating signal for adjacent row adjustment to said thermal head, at least once.

8. Thermal printer as set forth in claim 5, wherein said adjusting means comprises means for detecting the dot pattern density in the row dot pattern data.

9. Thermal printer as set forth in claim 8, further comprising:

row adjustment means for generating heat generating signal for adjacent row adjustment, at least once, relative to the row dot pattern data to adjust the density difference in adjacent rows upon comparison of the row dot pattern data with the preceding row dot pattern data, and in addition to said heat generating signal for row adjustment; and

means for applying said heat generating signal for adjacent row adjustment at least once to said thermal head.

10. Thermal printer comprising:

a thermal head having a printing part of at least n numbers of dots in a row;

adjusting means for driving said thermal head and for generating a heat generating signal for adjustment in accordance with a dot driving distribution of the printing part of said n members of dots upon driving of said thermal head in accordance with one row dot pattern data to be printed; and

applying means for applying said row dot pattern data and said heat generating signal for adjustment to said thermal head.