Information
-
Patent Grant
-
6476841
-
Patent Number
6,476,841
-
Date Filed
Wednesday, September 26, 200122 years ago
-
Date Issued
Tuesday, November 5, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Beyer Weaver & Thomas, LLP
-
CPC
-
US Classifications
Field of Search
US
- 347 172
- 347 173
- 347 213
- 347 174
- 347 176
- 400 12001
- 400 12002
-
International Classifications
-
Abstract
A thermal transfer printer is described. The thermal transfer printer includes a transfer roller, a first platen, a thermal transfer printing section, and a second platen. The transfer roller is operable to heat first ink for transfer of the first ink from a first ink film to a printing medium. The transfer roller presses the first ink film and the printing medium against the first platen. The thermal transfer printing section is operable to heat second ink for transfer the second ink from a second ink film to the printing medium. The thermal transfer printing section presses the second ink film and the printing medium against the second platen.
Description
BACKGROUND OF THE INVENTION
The present invention relates to printers, and more specifically, to apparatus and methods for printing a metallic layer and a regular color layer.
Thermal printers are used for printing various documents including personal identification cards. Typically, these identification cards have images on their surfaces printed in various colors. Some cards have images printed in metallic color.
In the prior art, there are thermal printers that print on a printing medium in regular colors such as cyan, magenta, yellow, and black and white. In order to print a background layer on the printing medium, a separate pre-printing process for applying a metallic layer on the medium is necessary. However, the application of the metallic layer poses some problems. For example, the metallic printing prior to the regular color printing inevitably incurs some lead time between the two printing steps. Furthermore, it is difficult to keep surfaces printed in metallic colors clean until the time when the regular color printing is performed on the metallic layer.
In view of these and other issues, it would be desirable to have a technique allowing a thermal transfer printer to print in metallic colors and regular colors efficiently and inexpensively.
SUMMARY OF THE INVENTION
According to various embodiments of the present invention, a thermal transfer printer includes a roller printing section for transferring metallic ink to a printing medium as a background layer, and a thermal transfer printing section for printing images by transferring regular color ink to the top of the background layer. Thus, the embodiments are capable of efficiently transferring a metallic ink layer to the whole area of a printing medium, and then transferring images using regular color ink on the metallic ink layer.
In some embodiments, the roller printing section includes a transfer roller and a first platen. The transfer roller is operable to heat metallic ink on a metallic ink film for transfer of metallic ink from a metallic ink film to a printing medium. The transfer roller presses the metallic ink film and the printing medium against the first platen. The thermal transfer printing section is operable to heat the regular color ink for transfer the regular color ink from a regular color ink film to the printing medium. The thermal transfer printing section presses the regular color ink film and the printing medium against a second platen.
In some specific embodiments, the thermal transfer printing section includes an intermediate transfer film, a print head, and an intermediate transfer roller. The print head has a plurality of resistance heating elements for transfer of the regular color ink from the regular color ink film to the intermediate transfer film. The intermediate transfer roller is operable to heat the regular color ink on the intermediate transfer film for transfer of the regular color ink from the intermediate transfer film to the printing medium.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWING
The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1
is cross-sectional view of a thermal transfer printer of a specific embodiment according to the present invention.
FIG. 2
is a cross-sectional view of a thermal transfer printer of an alternative embodiment according to the present invention.
FIG. 3
is a cross-sectional view of a specific example of the ink film used for the embodiments of the thermal transfer printer according to the present invention described referring to
FIGS. 1 and 2
.
FIG. 4
is cross-sectional view of a card during the printing process utilizing a specific embodiment of the method according to the present invention.
FIG. 5
cross-sectional view of the card after the printing process utilizing a specific embodiment of the method according to the present invention.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
Various embodiments of the present invention will now be described in detail with reference to the drawings, wherein like elements are referred to with like reference labels throughout.
Various embodiments of the present invention (i) transfer metallic ink to a printing medium as a background layer by utilizing a “roller printing” section, and then (ii) print images by transferring regular color ink to the top of the background layer by utilizing a “thermal transfer printing” section. Thus, the embodiments enables efficient transfer of a metallic ink layer to the whole area of a printing medium, and transfer of images using regular color ink on the metallic ink layer.
In this specification, “metallic ink” includes any ink which includes metallic substance such as metallic powder, metallic film or the like. Thus, the metallic ink includes, for example, gold color ink, silver color ink, and bronze (or copper) color ink. Similarly, a “metallic ink film” includes any ink film which carries metallic ink thereon. Thus, the metallic ink film includes metallic substance such as metallic powder, metallic film or the like. “Regular color ink” means any ink other than the metallic ink, which includes, for example, cyan ink, magenta ink, yellow ink, black ink, and white ink. A “regular color ink film” includes any film which carries regular color ink thereon.
Also, in this specification, an “ink film” includes any ink film which carries metallic ink or regular color ink. Thus, the ink film includes an ink film
122
, regular color ink films
140
and
240
, and an intermediate transfer film
148
described in detail below referring to
FIGS. 1 and 2
.
FIG. 1
is a cross-sectional view of a thermal transfer printer
100
of a specific embodiment according to the present invention. The thermal transfer printer
100
includes a roller printing section
102
, a thermal transfer printing section
104
, and a controller
106
within a housing
108
. A printing medium
110
is fed along a medium flow path
112
from left to right in FIG.
1
.
FIG. 1
shows three locations of the printing medium
110
in the thermal transfer printer
100
.
Suitable polymers for the printing medium
110
include polyvinylchloride (PVC), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), polypropylene sulfate (PPS), and polyethylene terephthalate glycol (PETG). Circles shown in
FIG. 1
represent rollers or platens, and elongated rectangulars
110
in
FIG. 1
represent cards or plate-like materials used as the printing medium
110
.
The roller printing section
102
includes a transfer roller
120
which is operable to heat metallic ink on the ink film
122
, thereby transferring the metallic ink from the ink film
122
to the printing medium
110
. In order to heat the metallic ink, the transfer roller
120
has a heater
124
therein. In order to apply pressure to the ink film
122
and the printing medium
110
, the transfer roller
120
is mechanically coupled to a pressure mechanism
126
which presses the transfer roller
120
against a platen
128
. The pressure mechanism
126
includes, for example, a spring. Thus, the transfer roller
120
presses the ink film
122
and the printing medium
110
against the platen
128
. The ink film
122
includes at least one of a gold color layer, a silver color layer, and a bronze color layer on a base film. The base film is made from plastic materials including polyethylene terephthalate (PET).
The platen
128
included in the roller printing section
102
in this specific embodiment is a roller having a rubber layer thereon. However, the platen
128
may be any other suitable type of platen including a flat platen. Feeding rollers
130
and
132
feed the printing medium
110
onto the transfer roller
120
and the platen
128
along the medium flow path
112
. The controller
106
controls rotational speeds and directions of the transfer roller
120
and the feeding roller
130
appropriately.
The thermal transfer printing section
104
is operable to heat regular color ink on the regular color ink film
140
for transfer the regular color ink from the regular color ink film
140
to the printing medium
110
. The regular color ink film
140
includes at least one of a cyan color layer, a magenta color layer, a yellow color layer, a black color layer, and a white color layer on a base film. The base film is made from plastic materials including polyethylene terephthalate (PET).
The thermal transfer printing section
104
includes a printing head
142
having a plurality of resistance heating elements
144
, and a platen
146
. The resistance heating elements
144
apply heat to the regular color ink film
140
based on electric drive pulses representing image data. The printing head
142
presses the regular color ink film
140
and the intermediate transfer film
148
against the platen
146
, thereby transferring the regular color ink to the intermediate transfer film
148
by heat and pressure. The intermediate transfer film
148
constitutes a closed loop, which rotates counterclockwise in
FIG. 1
supported by feeding rollers
150
,
152
,
154
and
156
.
The regular color ink transferred from the regular color ink film
140
to the intermediate transfer film
148
is carried counter clockwise to a point where an intermediate transfer roller
158
and a platen
160
contact the printing medium
110
. In order to determine the exact position of the printing medium
110
, the thermal transfer printing section
104
includes a sensor
162
which detects a predetermined point on the printing medium
110
by utilizing, for example, an optical sensing technique. Feeding rollers
164
and
166
feed the printing medium
110
onto the intermediate transfer roller
158
and the platen
160
along the medium flow path
112
. The controller
106
controls rotational speeds and directions of the feeding roller
164
appropriately.
The printing medium
110
is positioned on a predetermined point on the medium flow path
112
by using the sensor
162
and the feeding roller
164
controlled by the controller
106
. Then, the feeding rollers
164
and
166
feed the printing medium
110
onto the intermediate transfer roller
158
and the platen
160
along the medium flow path
112
. The intermediate transfer roller
158
presses the intermediate transfer film
148
and the printing medium
110
against the platen
160
, thereby transferring the regular color ink from the intermediate transfer film
148
to the printing medium
110
by pressure. Feeding rollers
170
and
172
feed the printing medium
110
out of the housing
108
of the thermal transfer printer
100
along the medium flow path
112
. The controller
106
controls rotational speeds and directions of the feeding rollers
170
and
172
appropriately.
FIG. 2
is a cross-sectional view of a thermal transfer printer
200
of an alternative embodiment according to the present invention. The thermal transfer printer
200
includes the roller printing section
102
, a thermal transfer printing section
204
, and the controller
106
within the housing
108
. The differences between the embodiments shown in
FIGS. 1 and 2
mainly reside in the thermal transfer printing section
204
. Thus, it should be appreciated that elements in
FIG. 2
which are assigned the same reference labels as shown in
FIG. 1
have the same functionalities as those of
FIG. 1
with the exception that the elements are designed to be coordinated with the thermal transfer printing section
204
.
The thermal transfer printing section
204
is operable to heat regular color ink on the regular color ink film
240
for transfer the regular color ink from the regular color ink film
240
to the printing medium
110
. The regular color ink film
240
includes at least one of a cyan color layer, a magenta color layer, a yellow color layer, a black color layer, and a white color layer on a base film, which is made from plastic materials including PET.
The thermal transfer printing section
204
includes a printing head
242
having a plurality of resistance heating elements
244
, and a platen
246
. The resistance heating elements
244
apply heat to the regular color ink film
240
based on electric drive pulses representing image data. The printing head
242
presses the regular color ink film
240
and the printing medium
110
against the platen
246
, thereby transferring the regular color ink from the regular color ink film
240
to the printing medium
110
by heat and pressure.
In the above-described embodiments referring to
FIGS. 1 and 2
, the transfer roller
120
is positioned upstream relative to the thermal transfer printing sections
104
and
204
along the medium flow path
112
of the printing medium
110
. Such an arrangement may be desirable where, for example, the metallic ink on the ink film
122
is printed on the printing medium
110
first, and then the regular color ink on the regular color ink films
140
and
240
is printed on the printing medium
110
since the thermal transfer printers
100
and
200
can efficiently print the metallic ink as a background layer on the whole surface of one side of the printing medium
110
.
FIG. 3
is a cross-sectional view of a specific example of the ink film
122
used for the embodiments of the thermal transfer printer according to the present invention described referring to
FIGS. 1 and 2
. The ink film
122
includes a base film
300
, an adhesive layer
302
, and a metallic color layer
304
. The base film is made from plastic materials such as PET. The adhesive layer
302
is interposed between the base film
300
and the metallic color layer
304
for affixing the metallic color layer
304
to the base film
300
. The metallic color layer
304
includes at least one of a gold color layer, a silver color layer, and a bronze color layer, each of which contains metallic powder exhibiting the corresponding metallic color. In an alternative embodiment, the ink film
122
includes an opaque layer on the adhesive layer
302
instead of the metallic color layer
304
.
FIG. 4
is a cross-sectional view of a card
400
during the printing process utilizing a specific embodiment of the method according to the present invention. Before the printing process utilizing the thermal transfer printers
100
and
200
, the card
400
includes only the printing medium
110
. The specific embodiment of the method according to the present invention will now be described referring to
FIGS. 1
,
4
and
5
.
First, the thermal transfer printer
100
receives the card
400
from an opening provided on the housing
108
. The feeding rollers
130
and
132
feed the card
400
onto the transfer roller
120
and the platen
128
along the medium flow path
112
. Next, the transfer roller
120
transfers the metallic color layer
304
from the ink film
122
to an upper surface of the printing medium
110
of the card
400
. A transferred metallic color layer
404
is affixed to the printing medium
110
by heat and pressure applied by the transfer roller
120
, the heater
124
, and the platen
128
. Then, an adhesive layer
406
is applied to a surface of the transferred metallic color layer
404
for improving adhesiveness between the transferred metallic color layer
404
and regular color layers printed on the transferred metallic color layer
404
.
FIG. 5
is a cross-sectional view of the card
400
after the printing process utilizing a specific embodiment of the method according to the present invention. After printing the metallic color layer
404
, the feeding rollers
164
and
166
feed the card
400
onto the intermediate transfer roller
158
and the platen
160
along the medium flow path
112
. The card
400
is positioned on a predetermined point on the medium flow path
112
by using the sensor
162
and the feeding roller
164
controlled by the controller
106
. Then, the feeding rollers
164
and
166
feed the card
400
onto the intermediate transfer roller
158
and the platen
160
along the medium flow path
112
. The intermediate transfer roller
158
presses the intermediate transfer film
148
and the card
400
against the platen
160
, thereby transferring a cyan color layer
502
, a magenta color layer
504
, a yellow color layer
506
, a black color layer
508
, and a white color layer
510
from the intermediate transfer film
148
to a surface of the adhesive layer
406
. The order of printing the regular color layers may be modified based on the color layer materials used. It should be appreciated that one or more layers among the cyan color layer
502
, the magenta color layer
504
, the yellow color layer
506
, the black color layer
508
, and the white color layer
510
may be omitted to be printed on the card
400
.
The specific embodiment of the method according to the present invention described above referring to
FIGS. 1
,
4
and
5
can be implemented by utilizing the thermal transfer printer
200
illustrated in
FIG. 2
in a similar manner except that the regular color printing is performed by the thermal transfer printing section
204
rather than the thermal transfer printing section
104
. Thus, further detail is omitted.
In the specific embodiments described above, the regular color printing by the thermal transfer printing sections
104
and
204
can be implemented by a single thermal head. However, it should be appreciated that a plurality of thermal heads can be used for the regular color printing.
In the specific embodiments described above, the image layer printing by the thermal transfer printing sections
104
and
204
can be implemented by a single thermal head. However, it should be appreciated that a plurality of thermal heads can be used for the regular color printing. For example, five separate thermal heads can be used for five colors (e.g., cyan, magenta, yellow, and black and white) for the thermal transfer printing sections
104
and
204
.
In the above-described specific embodiments of the thermal transfer printer according to the present invention described referring to
FIGS. 1 and 2
, the feeding rollers
130
,
132
,
164
,
166
,
170
and
172
are appropriately positioned along the medium flow path
112
so that the position of the printing medium
110
is controlled to go back and forth along the medium flow path
112
based on a specific printing process (e.g., watermark layer printing, image layer printing, and opaque layer printing) which is applied to the printing medium
110
.
In the above embodiments of the thermal transfer printer according to the present invention described referring to
FIGS. 1 and 2
, the controller
106
can be implemented by any combination of software and/or hardware. For example, the controller
106
can be implemented by a microprocessor, a memory device which stores instruction codes and data, and an interface which drives external devices such as the feeding rollers, the transfer roller, and the intermediate transfer roller.
In the above embodiments of the thermal transfer printer according to the present invention described referring to
FIGS. 1 and 2
, the roller printing section
102
utilizes the transfer roller
120
for transfer of the metallic ink. However it should be appreciated that any suitable thermal transfer printing mechanism may be used for the roller printing section
102
. Such a mechanism includes, for example, the thermal transfer printing section
104
using the intermediate transfer film
148
, and the thermal transfer printing section
204
using the printing head
242
having the resistance heating elements
244
.
Although only a few embodiments of the present invention have been described in detail, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. For example, although the illustrated embodiments have been described primarily in the context of a thermal transfer printer for printing images on a plastic card, it should be appreciated that various materials may be used for embodiments of the thermal transfer printer according to the present invention. Therefore, it should be apparent that the above described embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
Claims
- 1. A thermal printer for transferring first ink from a first ink film to a printing medium, and transferring second ink from a second ink film to the printing medium, comprising:a transfer roller operable to heat the first ink for transfer of the first ink from the first ink film to the printing medium; a first platen against which the transfer roller presses the first ink film and the printing medium; a thermal transfer printing section operable to heat the second ink for transfer the second ink from the second ink film to the printing medium; and a second platen against which the thermal transfer printing section presses the second ink film and the printing medium, wherein the transfer roller is positioned upstream relative to the thermal transfer printing section along a medium flow path of the printing medium, and wherein the thermal transfer printing section includes an intermediate transfer film, a print head having a plurality of resistance heating elements for transfer of the second ink from the second ink film to the intermediate transfer film, and an intermediate transfer roller operable to heat the second ink on the intermediate transfer film for transfer of the second ink from the intermediate transfer film to the printing medium.
- 2. The thermal printer of claim 1, wherein the intermediate transfer film constitutes a closed loop.
- 3. The thermal printer of claim 2, wherein the transfer roller and the first platen apply heat and pressure to the first ink film for transfer of metallic ink.
- 4. The thermal printer of claim 3, wherein the intermediate transfer roller and the second platen apply heat and pressure to the second ink film for transfer of regular color ink.
Foreign Referenced Citations (3)
Number |
Date |
Country |
6-262784 |
Sep 1994 |
JP |
08-118693 |
May 1996 |
JP |
10-175375 |
Jun 1998 |
JP |