Thermal heat and thermal printer

Details Thermal heat and thermal printer Thermal heat and thermal printer

2000-11-08

2002-01-15

Tran, Huan (Department: 2861)

Incremental printing of symbolic information

Thermal marking apparatus or processes

Specific resistance recording element type

C347S175000, C347S205000

Reexamination Certificate

active

06339444

ABSTRACT:

TECHNICAL FIELD
The present invention relates to a thermal head suitable for color printers or the like, a substrate used in the thermal head, and an image recording method.
BACKGROUND ART
A structure of a single-line thermal head comprising a plurality of exothermic resistors formed in a line will be described, with reference to FIG.
1
and FIG.
2
.
FIG. 1
is a perspective view of a single-line type thermal head, and
FIG. 2
is a sectional view of the thermal head, taken along the line A-A′ in FIG.
1
. In these figures, reference symbol
101
denotes an alumina substrate, and on the upper face of this substrate
101
, there are formed respective parts of the thermal head, and on the bottom face thereof is adhered a radiation fin
102
. The radiation fin
102
is for efficiently radiating heat generated in each part in the operation of the thermal head, into the air.
Reference symbol
103
denotes exothermic resistors, which generate heat when an electrical current is made to flow between a common electrode
104
and individual lead electrodes
105
. The common electrode
104
is an electrode common to all exothermic resistors
103
, and is connected respectively to contact portions
106
of each exothermic resistor
103
. The individual lead electrodes
105
are connected to each contact portion
107
of each exothermic resistor
103
, and wired respectively to each terminal
109
of an IC (Integrated Circuit)
108
.
Reference symbol
110
denotes a glaze, formed in a half spindle shape on the upper face of the alumina substrate
101
, and functions as a heat reservoir for storing heat energy generated by the exothermic resistor
103
at the time of printing processing. Reference symbol
111
denotes a flexible printed circuit board for connection, and a wiring for connecting with a controller of a printer body (not shown) is formed thereon. Reference symbol
112
denotes a protection layer, for protecting the exothermic resistor
103
and electrodes
104
,
105
from wear due to contact with the paper at the time of printing.
A production method of the thermal head in
FIG. 1
will now be described. At first, in order to remove dust on the surface of the alumina substrate
101
, the alumina substrate
101
is cleaned. After cleaning, a thin film of the exothermic resistors
103
is formed by sputtering using a sputtering system, on the upper face of the alumina substrate
101
, so that the exothermic resistor film has a predetermined sheet resistance. An electrode material (for example, aluminum) is then formed on the upper face of the thin film material of the exothermic resistors
103
by sputtering or a vapor deposition method.
A photoresist is then coated on the electrode material film, to thereby prepare a resist pattern of the common electrode
104
and the individual lead electrodes
105
by photolithography. The electrode material is etched using this photoresist pattern as a mask, to form the common electrode
104
and the individual lead electrodes
105
. The whole resist is then removed, and a new resist is coated on the thin film material of the exothermic resistors
103
, the common electrode
104
and the individual lead electrodes
105
.
Then, a resist pattern for forming the exothermic resistors
103
for each printing dot is formed by photolithography. A thin film consisting of the exothermic resistors
103
is divided into exothermic resistors
103
for each dot by etching. A protection film
112
is then formed on the upper part of the glaze
110
by sputtering, using a mask for forming the protection film. Then, the protection film
112
is subjected to a heat treatment, for realizing stabilization of a resistance value of the exothermic resistors and stabilization of intimate contact between the exothermic resistors and the electrode material.
An insulating film is formed in the IC mounting area, and an IC
108
is subjected to die bonding on this IC mounting area Terminals of the IC
108
and wire-bond terminals
109
of the individual lead electrodes
105
are connected by wire bonding, and seal the IC
108
, the wire bond portion and a part of the individual lead electrode
105
are sealed by a resin. A single-line thermal head is produced by the above-described production process.
As a second conventional example, there is shown a thermal head in FIG.
3
and
FIG. 4
(see Japanese Patent Application No. 62-217627).
FIG. 3
is a plan view of a double-line thermal head where a plurality of exothermic resistors are arranged in two lines in parallel, and
FIG. 4
is a sectional view, taken along the line B-B′ in FIG.
3
. As shown in these figures, a first alumina substrate
301
and a second alumina substrate
302
are connected with a metal plate
314
placed therebetween. The metal plate
314
is a common electrode and connected with other common electrode
313
.
Reference symbol
305
denotes a first exothermic resistor, and is connected to a first individual lead electrode
306
via a contact area
307
, and is connected to a common electrode
313
via a contact area
312
. A second exothermic resistor
309
is connected to a second individual lead electrode
315
via a contact area
316
, and is connected to a common electrode
313
via a contact area
310
. Reference symbol
311
denotes a protection layer, which protects the exothermic resistors
305
and
309
from wear due to contact with a sheet of paper to be printed.
As a conventional third example, there is a double-line thermal head having a section shown in FIG.
5
. In this figure, a wiring groove
318
is formed in an alumina substrate
300
, and a common electrode
317
is formed therein by embedding a bulk metal into the wiring groove
318
. A common electrode
313
is formed on the wiring groove
318
, and connected to the common electrode
317
.
The operation of the thermal head shown in
FIG. 1
will now be described with reference to FIG.
6
.
FIG. 6
shows an equivalent circuit of the thermal head, wherein reference symbol
120
denotes a power source, which supplies drive power for the thermal head. Reference symbol
103
denotes an exothermic resistor,
104
denotes a common electrode,
105
denotes an individual lead electrode, and
108
denotes a control IC.
At first, a data signal DATA corresponding to each exothermic resistor
103
is input at to the control IC
108
, synchronized with a clock signal CLK having a constant period transmitted from a printer body (not shown), and information of the data signal DATA is stored in a storage section inside the control IC
108
, upon “build up” of a latch signal LATCH. Based on the stored information, for example, when a strobe signal STB is “1”, the exothermic resistors
103
are energized to generate heat energy. Here, at the time of printing, printing information of the next line is transferred from the printer body synchronized with the clock signal CLK, by means of the data signal DATA. The control IC controls ON/OFF of the exothermic resistors
103
based on the data supplied from this control section. The thermal head substrate is secured to a heat sink
102
by means of double sided adhesive tape, adhesive or the like.
On the other hand, a heat sensitive paper made to develop color by the thermal head has a construction shown in FIG.
7
. This heat sensitive paper has such a construction that a cyan recording layer
712
, a magenta recording layer
713
and a yellow recording layer
714
are sequentially laminated on a base material
711
such as paper, and the surface is covered with a heat-resistant protection layer
715
. The cyan recording layer
712
has a structure such that microcapsules
717
are dispersed in the cyan developer
716
, and a cyan leuco dye
718
which reacts with the cyan developer
716
and makes it develop color is sealed in these microcapsules
717
.
The magenta recording layer
713
has a structure such that microcapsules
720
are dispersed in the magenta recording layer
713
mainly composed of a coupler
719
, and a magenta diazo dye
721
which reacts with the coupler
7

Affiliated with

Also associated with

Rating

Thermal heat and thermal printer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Thermal heat and thermal printer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal heat and thermal printer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2817902