Incremental printing of symbolic information – Thermal marking apparatus or processes – Record receiver and transfer medium feeding or driving means
Reexamination Certificate
1998-12-10
2001-05-29
Le, N. (Department: 2861)
Incremental printing of symbolic information
Thermal marking apparatus or processes
Record receiver and transfer medium feeding or driving means
C347S219000
Reexamination Certificate
active
06239827
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a thermoelectric printer which in particular is able to implement a high quality thermoelectric printing, regardless of the sizes of a take-up diameter of the ink coated film used for thermoelectric printing and taken up by a take-up shaft.
Description of the Related Art
For example, for prints, such as large size price tags at a supermarket, a thermoelectric printer is used. This thermoelectric printer is able to print on rather large size papers in clear, by a simple way and in short time.
FIG. 1
is a perspective diagram of a main part of an ink coated film feeding mechanism
100
of the conventional thermoelectric printer. As shown in
FIG. 1
, over a rectangular plate type thermal head
101
, a platen
103
which presses and transfers ink on an ink coated flm
102
to a paper
107
is disposed. The ink coated film
102
is taken up by a take-up shaft
104
rotating in a fixed torque to the counterclockwise direction. Between the take-up shaft
104
and the thermal head
101
, a ribbon feed roller
105
which drives the ink coated film
102
with friction by the same fixed torque of the take-up shaft
104
to the counterclockwise direction and gives the ink coated film
102
tension and carries the ink coated film
102
to the direction of an arrow X
1
is disposed. At the below right of the thermal head
101
, a ribbon brake roller
106
which gives the ink coated film
102
a certain brake to give tension to the ink coated film
102
is disposed.
At the upper left of the thermal head
101
, a first paper feed roller
108
constituted of a pair of rollers which carries the paper
107
in putting between the rollers by friction to the direction of an arrow X
2
in a fixed speed is disposed. At the upper right of the thermal head
101
, a second paper feed roller
109
constituted of a pair of rollers which carries the paper
107
in putting between the rollers by friction to the direction of an arrow X
2
in a fixed speed and works together with the first paper feed roller
108
is disposed. By the rotating control of a motor of a controller, this motor is not shown in
FIG. 1
, the take-up shaft
104
, above mentioned rollers
105
,
106
,
108
and
109
are rotated, and the ink coated film
102
is carried to the direction X
1
and the paper
107
is carried to the direction X
2
. While this carrying process, the ink coated film
102
and the paper
107
are pressed between the thermal head
101
and the platen
103
and the ink coated on the ink coated film
102
is transferred to the paper
107
by the thermoelectric printing. In this case, it is a premise that the ink coated film
102
and the paper
107
are carried on the thermal head
101
by the same feed torque.
In the conventional ink coated film feeding mechanism, the ink coated film
102
is taken up by the take-up shaft
104
with a fixed torque. However, the take-up diameter between the beginning and the ending of the take-up shaft
104
is different, therefore the feed torque applying to the ink coated film under taken up changes.
At this, the following formula (1) is formed in the relation among the feed power F applying to the ink coated film under taken up, the rotating torque T of the take-up shaft, the take-up diameter D increasing by the taking up of the ink coated film, the friction coefficient &mgr; between the ribbon feed roller and the ink coated film, and the power P which the ribbon feed roller presses and touches the ink coated film.
F
=(2
T/D
)+&mgr;
P
(1)
FIG. 2
is a graph showing the relation between the take-up diameter D and the feed power F. The unit of the take-up diameter D is mm and the unit of the feed power F is gram. As shown in
FIG. 2
, at the beginning of the take-up, the take-up diameter is small and the feed power is large, the tension of the ink coated film on the thermal head becomes too large and the problem that creases are formed on the ink coated film occurs.
On the contrary, at the ending of the take-up, the feed power F applying to the ink coated film becomes small, at the time when the paper is putted on the ink coated film on the thermal head, the slip between the paper and the ink coated film occurs, and the paper is stained by unnecessary ink and the thermal head is stained too, these problems occur. To solve these problems caused by the change of the feed power, as shown in
FIG. 1
, the conventional thermoelectric printer provides a clutch means
110
between the ribbon feed roller
105
and a roller rotating driving means which drives the ribbon feed roller
105
, this roller rotating driving means is not shown in FIG.
1
. This clutch means
110
is constituted of a first clutch plate
110
a
joining to the ribbon feed roller
105
by gears and a second clutch plate
110
b
glued a slipping material
110
c
. In this, this slipping material
110
c
is made of synthetic resin with special surface treatment. The second clutch plate
110
b
is directly joined to the roller rotating driving means which is not shown in FIG.
1
.
As mentioned above, the take-up shaft
104
and the ribbon feed roller
105
are rotating by a fixed torque respectively, however at the case that the feed power under taken up is large, the clutch means
110
slips the ribbon feed roller
105
and the rotating torque of the roller rotating driving means is not transferred and prevents creases from occurring. On the contrary, the feed power under taken up is small, the clutch means
110
transfers the rotating torque of the roller rotating driving means to the ribbon feed roller
105
and makes the ink coated film have tension and the occurrence of the stain is prevented.
However, in the above mentioned feed power changing solution using the special slipping material, the value starting slip has a variation, the problem of the stain and creases is not solved completely.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a thermoelectric printer in which paper and an ink coated film are not stained and creased regardless of the size of a take-up shaft taken up ink coated film.
To solve the above mentioned problems, the present invention provides at a thermoelectric printer which a ink coated film is taken up by a take-up shaft generating fixed rotating torque and said ink coated film is driven with friction by rotating torque of a film driving roller in one carrying route, paper is driven by paper driving rollers in the other carrying route, said ink coated film and said paper carried by said carrying routes are carried to the place between a thermal head and a platen, and said ink coated film and said paper are pressed and said paper is thermoelectrically printed, a take-up diameter detecting means for detecting the take-up diameter of the ink coated film taken up by said take-up shaft and a rotating torque control means for controlling the rotating torque of said film driving roller corresponding to the take-up diameter detected by said takeup diameter detecting means.
With this construction, the take-up diameter of the ink coated film is detected by the take-up diameter detecting means, the rotating torque of the film driving roller is controlled by the rotating torque control means corresponding to the sizes of the take-up diameter, the feed power applying to the ink coated film under taken up is able to be a suitable value, therefore at the place between the thermal head and the platen the ink coated film and the paper are able to be pressed by the same feed power and the paper is thermoelectrically printed and is not stained and creased.
REFERENCES:
patent: 4775869 (1988-10-01), Minowa
patent: 5168286 (1992-12-01), Okauchi et al.
patent: 2-31756 (1990-02-01), None
patent: 5-58386 (1993-08-01), None
patent: 5-309901 (1993-11-01), None
patent: 9-169147 (1997-06-01), None
Feggins K.
Foley & Lardner
Le N.
NEC Corporation
LandOfFree
Thermoelectric 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 Thermoelectric printer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoelectric printer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2563774