JPH11235848A - Braille printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer type braille printer capable of forming brailles having excellent printing quality in the thermal transfer type braille printer in which brailles are formed on paper by using such a thermal transfer ribbon for the brailles having thermal expansive ink applied thereto. SOLUTION: The braille printer is equipped with a plurality of heating resistors 50 arranged in a linear shape, a thermal head 2, in which a prescribed heating resistor 50 is allowed to generate heat and the prescribed region of such a thermal transfer ribbon 6 for brailles that thermal expansive ink is applied thereto is heated and the thermal expansive ink in the prescribed region is transferred on the surface of a form 5, and a foaming part 4 in which transferred thermal expansive ink is heated and foamed. Heat reserving heaters 60, 62, 64 which thermally insulate the thermal expansive ink at the prescribed temperature are equipped in the tip part of the thermal head 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer type Braille printer for producing Braille on plain paper using a thermal transfer ribbon for Braille coated with a thermal expansion ink.

[0002]

2. Description of the Related Art As one of information transmission means for a blind person, there is Braille in which information is acquired by touching with a finger. There is a Braille printer as an apparatus for creating the Braille on paper or the like. In the past, the mainstream of Braille printers was the dot impact method, in which the braille was created by hitting a metal pin from the back of the paper to make the paper protrude. Due to the problem of inconsistent quality and the problem of excessively loud noise during print creation, in recent years, thermal transfer Braille printers have been proposed that can produce high quality printing with quiet printing noise. I have.

[0003]

For example, Japanese Patent Application No. 8-35 filed on Dec. 26, 1996 by the present applicant.
No. 9884 proposes a thermal transfer type Braille printer using a thermal transfer ribbon for Braille. The operation of the proposed Braille printer will be described with reference to FIG. In FIG. 4, the paper 5 sandwiched between the driving rollers 108a and 108b and the guide rollers 104a and 104b is conveyed from right to left in the drawing by rotation of the driving rollers 108a and 108b. . Drive rollers 108a, 108b and guide rollers 104a, 104b
A thermal head 100 in which a plurality of heating resistors are arranged in series is provided, and a platen roller 106 is provided to face the thermal head 100.

[0004] Thermal head 100 and platen roller 1
06, the paper 5 and the Braille thermal transfer ribbon 6 are sandwiched, and a predetermined heating resistor is heated based on the print data, so that the thermally expandable ink of the Braille thermal transfer ribbon 6 is transferred to the paper 5. Has become. The thermal transfer ribbon 6 for braille is stretched from a supply reel 8 to a take-up reel 10 via a thermal head 100, and the drive roller 1
08a, 108b and the take-up reel 1 which is moved out of the supply reel 8 together with the paper 5 being conveyed.
It can be wound up to zero.

The cross-sectional structure of the Braille thermal transfer ribbon 6 will be described with reference to FIG. The thermal transfer ribbon 6 for braille
A release layer 6c separating from the film-shaped transparent substrate 6b at the time of thermal transfer and a thermally expandable ink layer 6d containing a foamed resin are adhered to one surface of the film-shaped transparent substrate 6b at the time of transfer. A heat-sensitive adhesive layer 6e is laminated in this order, and on the other surface of the film-shaped transparent substrate 6b, a heat-resistant lubricating layer 6 having heat resistance and slipperiness and coming into contact with the thermal head 100 is provided.
a is formed.

At the time of printing, the thermal transfer ribbon 6 for braille and the paper 5 having such a configuration are placed on the thermal head 10.
By causing a predetermined heating resistor (not shown) of the thermal head 100 to generate heat in a state where the heating resistor is sandwiched between the zero and the platen roller 106 with a predetermined pressing force, a position corresponding to the heating resistor that has generated heat is generated. The heat-sensitive adhesive layer 6e of the thermal transfer ribbon 6 for braille melts and adheres to the paper 5. Next, the thermal transfer ribbon 6 for Braille moves with the conveyance of the paper 5 and gradually moves away from the surface of the paper 5, and accordingly, the thermally expandable ink layer 6 d and the release layer 6 c on the heat-sensitive adhesive layer 6 e adhered to the surface of the paper 5. Is separated from the film-shaped transparent substrate 6b, and the transfer section 110 is formed on the surface of the paper 5. Thereafter, the sheet 5 on which the transfer unit 110 is formed is moved to the foaming unit 102 in which the heating device is built.
, The heat-expandable ink layer 6 d of the transfer unit 110 is heated and foamed, and the Braille 11 having a predetermined thickness and diameter is obtained.
2 are formed. The heating device of the foaming section 102 can be composed of, for example, a glass fixing roller as a heat source and a rubber roller disposed opposite to the fixing roller. The thermal expansion ink layer 6d of the transfer section 110 on the paper 5 can be heated and foamed while the paper 5 is sandwiched and moved between the rotating glass fixing roller and the rubber roller.

[0007] The above is the operation of creating a Braille by the proposed Braille printer, but in reality it has the following problems. First, the height of the Braille to be created needs to be about 0.3 to 0.4 mm in order to ensure tactile reading, and the heating in the foaming section 102 causes the thermally expandable ink layer 6d to foam, and this height is used. In order to obtain the above, it is necessary to make the thickness of the thermally expandable ink layer 6d of the transfer section 110 before foaming about several tens μm. This thickness is a special thickness that is ten and several times greater than that of a normal thermal transfer ribbon for office automation (OA). Therefore, even when the adhesive of the heat-sensitive adhesive layer 6e is melted and sufficiently adhered to the surface of the paper 5, the heat-expandable ink layer 6d and the release layer 6c of the transfer section 110 are separated from the film-shaped transparent base material 6b. Since the thickness of the heat-expandable ink layer 6d of the transfer portion 110 is large, separation from the heat-expandable ink layer 6d of the non-transfer portion wound up together with the film-like transparent base material 6b does not work well, and is adhered to the paper 5. Heat-sensitive adhesive layer 6e
The heat-expandable ink layer 6d is peeled off from the paper and wound up together with the release layer 6c and the film-like transparent base material 6b, or the heat-sensitive adhesive layer 6e once adhered to the paper 5
Then, there arises a problem that the transfer unit 110 is peeled off together with the film-shaped transparent substrate 6b by peeling off the paper fibers together with the paper fibers.

[0008] As described above, when the ink on the thermal transfer ribbon for Braille is thermally transferred by the thermal head, the peeling of the printed ribbon from the printed portion (separation of the transfer portion and the non-transfer portion) cannot be performed smoothly. There is a problem that the printing quality is deteriorated.

The thermal expansion ink layer 6d of the transfer section 110 transferred to the paper 5 foams to a desired height by heating to a temperature of about 80 ° C. to 150 ° C. If this is done, only the surface portion of the heat-expandable ink layer 6d foams, and the inside of the heat-expandable ink does not expand sufficiently and the foaming ends, resulting in a problem that a desired height and shape cannot be obtained. . Further, in the case of the above-described heating device using the glass fixing roller and the rubber roller opposed thereto, the roller surface directly contacts both sides of the paper and the transfer unit 110
Is pressed, the thermal expansion ink layer 6d of the transfer unit 110 is pressed.
However, there is a problem that it is difficult to specify the device conditions for performing normal foaming because the pressure for suppressing the foaming works. In the case where a heating unit having a heat radiating surface substantially parallel to the paper surface is used instead of the two rollers, normal foaming is performed if the heat-expandable ink layer 6d directly contacts the heat radiating surface. Thus, the desired height and shape cannot be obtained, but if the thermally expandable ink layer 6d is moved away from the heat radiation surface, the heating device becomes large and inefficient. The problems described above are technical issues that have not been mentioned or solved in the above-described proposed thermal transfer type Braille printer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal transfer type Braille printer capable of producing Braille of excellent print quality.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a Braille thermal transfer ribbon having a plurality of heating resistors arranged in a straight line, heating a predetermined heating resistor, and applying a heat-expandable ink. In a Braille printer having a thermal head that heats a predetermined area to transfer the thermally expandable ink in the predetermined area to the paper surface, and a foaming section that heats the transferred thermally expandable ink and foams it, The present invention is further achieved by a Braille printer, further comprising a heat retaining means for keeping the heat-expandable ink at a predetermined temperature.

In the Braille printer according to the present invention, the heat retaining means has a heating mechanism for heating the thermal head. The heat retaining means is characterized by applying a voltage for heat retention lower than the voltage applied at the time of transfer to the plurality of heating resistors to keep the thermal head at a predetermined temperature. Further, the heat retention voltage is a pulse voltage.

It is another object of the present invention to provide a thermal transfer ribbon for braille coated with a heat-expandable ink by having a plurality of heat-generating resistors arranged in a straight line and causing a predetermined heat-generating resistor to generate heat. In a Braille printer having a thermal head that heats and transfers a thermally expandable ink in a predetermined area to the surface of a sheet and a foaming section that heats and transfers the transferred thermally expandable ink to a foam, the foamed portion is heated from the surface of the paper. This is achieved by a Braille printer comprising a heating unit for heating the expandable ink, and a preheating unit provided at a stage preceding the heating unit and heating from the back side of the paper. In the Braille printer according to the present invention, the foaming section has a suction mechanism for suctioning a sheet passing through the heating section from the back surface.

Further, the object is to provide a thermal transfer printing method for heating a predetermined area of a thermal transfer ribbon for Braille coated with a thermal expandable ink to transfer the thermal expandable ink in the predetermined area to the surface of a paper. This is achieved by a thermal transfer printing method characterized by maintaining the heat-expandable ink at a predetermined temperature so that the heat-expandable ink in a predetermined area is easily separated from the thermal transfer ribbon for braille.

The present invention having the above-described configuration has been made based on the following findings. That is, in a typical thermal transfer printer for OA, for example, when the ink is warmed by transfer heat and the ribbon is separated from the paper in a soft state, the ink does not sufficiently adhere to the paper and peels off from the paper together with the base film. Phenomenon occurs. for that reason,
In a typical thermal transfer printer technique, the ink ribbon and the paper are not separated until the transferred ink is sufficiently cooled.

However, the thermal transfer ribbon for braille used in the present invention has an extremely thick ink layer as compared with the ink ribbon for OA as described above, and when peeling the paper and the thermal transfer ribbon for braille, The present inventors have found that in order to shear and separate the ink layer of the transfer portion and the ink layer of the non-transfer portion, it is necessary to soften (ie, fluidize) the ink layer to some extent to reduce the shear stress. Was. Because of this, beyond the common sense of the conventional thermal transfer technology, it has been demonstrated that it is effective to preheat the ink layer and warm the ink layer to some extent and soften it when peeling the ribbon and ink. This has led to the present invention.

As a means for achieving this, the temperature lower than the temperature at which the heating resistor of the thermal head generates heat during printing is set to 40.
The thermal head itself is heated (preheated) to a temperature of about 60 ° C. to 60 ° C. to maintain the temperature, and the heat generated by the temperature is transmitted to the thermally expandable ink layer, so that the transfer portion and the non-transfer portion can be easily separated. I did it. As described above, according to the present invention, control for maintaining the thermal head at a predetermined temperature is performed, and peeling after transfer (separation of a transfer portion and a non-transfer portion) is performed using heat of the thermal head. Therefore, it is possible to create Braille with improved printing quality.

Therefore, according to the present invention, even if the thickness of the thermally expandable ink layer in the transfer portion is large, it can be easily separated from the thermally expandable ink layer in the non-transfer portion wound up with the base material. The heat-expandable ink layer is peeled off from the heat-sensitive adhesive layer adhered to the paper and rolled up together with the base material. A braille printer that does not wind up can be realized.

Further, the foaming part of the Braille printer of the present invention is
A pre-heating unit that heats the thermal expansion ink from the back side of the paper is provided before the heating unit that heats the thermal expansion ink from the paper surface, so that a certain amount of heat is preliminarily applied to the thermal expansion ink. It is possible to prevent the ink from being rapidly heated. Therefore, only the surface of the heat-expandable ink layer foams and the internal ink does not end up expanding sufficiently without swelling, so that high-quality Braille of a desired height and shape can be obtained. .

Further, since a suction mechanism for sucking the paper passing through the heating unit from the back surface is provided, the surface of the heating unit does not directly contact the paper and press the transfer unit. Since the thermal expansion ink layer can be heated at a substantially uniform temperature while maintaining a constant distance from the transfer unit, it is possible to create high-quality Braille with uniform height and a compact size. A highly efficient heating device can be realized.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A braille printer according to an embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of a Braille printer according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic side sectional view of a Braille printer according to the present embodiment. In FIG. 1, in the Braille printer, a sheet 5 is carried in from a sheet feeding unit 80 provided above the housing 1. As the paper 5, so-called plain paper can be used. By appropriately changing the configuration of the paper feed unit 80 and a paper extraction unit (not shown) in the housing 1, a cut sheet, a stock form, a roll paper, or the like can be formed. It can be used. Of course, it is also possible to manually insert the sheets 5 one by one into the sheet take-out section without using the sheet feeding section 80.

The sheet take-out section (not shown) conveys the sheet 5 by driving a sheet take-out DC motor 14. The taken out paper 5 is driven by a driving roller 18a,
18b and guided by a paper guide (not shown)
The position of the front end of the paper 5 is detected by a position detection system such as a photo sensor (not shown), and the paper 5 is conveyed to the front end of the thermal head 2 and temporarily stopped. The thermal head 2 is arranged with its tip end facing downward. The tip of the thermal head 2 will be described later with reference to FIG.
A plurality of heating resistors are arranged in a line in a direction substantially perpendicular to the transport direction of the paper 5.

A platen roller 20 that rotates while sandwiching the sheet 5 and the thermal transfer ribbon 6 for braille between the thermal head 2 and the thermal head 2 is located at a position facing the distal end of the thermal head 2.
Further, a transport roller 21 is provided in front of the thermal head 2 in the sheet transport direction, and is located opposite to the platen roller 20. The Braille thermal transfer ribbon 6 sandwiched together with the paper 5 between the leading end of the thermal head 2 and the platen roller 20 is stretched from a supply reel 8 to a take-up reel 10 via the leading end of the thermal head 2. It moves with the paper 5 being conveyed with the rotation of the conveyance roller 20 and the conveyance roller 21, is fed from the supply reel 8, and is taken up on the take-up reel 10. Thermal head 2 from supply reel 8
A guide roller 28 is provided between the leading end portion and a guide roller 30 is provided between the leading end portion of the thermal head 2 and the take-up reel 10. The thermal transfer ribbon 6 for braille is sent to the leading end at a predetermined angle, and the thermal transfer ribbon 6 for braille at a predetermined angle from the leading end of the thermal head 2.
Can be sent out.

Platen roller 20 and transport roller 21
Transport rollers 22a, 22 provided on the paper transport direction side of
In front of b, a paper transport guide (not shown) is provided to bend the paper 5 in the horizontal direction, and further provided with a foaming part 4 shown by a broken line in the figure via a guide roller 24.

The foaming section 4 is a heating section for heating the thermally expandable ink layer 6d of the thermal transfer ribbon 6 for braille (hereinafter referred to as a transfer section) transferred onto the surface of the sheet 5 from the side of the sheet 5 on which the sheet 5 is conveyed. The preheating section 40 is provided at the front of the preheating section 40 for heating the thermally expandable ink layer 6d of the transfer section from the back surface of the paper 5. Further, a paper suction fan 44, which is a suction mechanism for sucking the paper 5 passing through the heating unit 42 from the back surface thereof, is provided opposite to the heating unit 42 with respect to the transport path of the paper 5. In front of the foaming section 4 in the paper transport direction, transport rollers 26a and 2 for discharging paper from the housing 1 are provided.
6b is provided.

The transport rollers 18a, 18b,
The reference numerals 21, 22 a, 22 b, 26 a, and 26 b are driven to rotate in conjunction with each other by a sheet conveying pulse motor 12 via a belt mechanism (not shown). Further, in synchronization with the movement of the sheet 5 conveyed by the driving of the pulse motor 12 for sheet conveyance, the thermal transfer ribbon 6 for braille that is unwound from the supply reel 8 and wound on the take-up reel 10 during printing is shown in FIG. Are driven by a ribbon driving pulse motor, which is omitted. The sheet transport pulse motor 12 and the ribbon drive pulse motor are generally controlled by a sheet transport and ribbon drive pulse motor control system 16.

Next, a schematic configuration of the thermal head 2 of the Braille printer according to the present embodiment will be described with reference to FIGS. 2A is a side view of the thermal head 2 according to the present embodiment, FIG. 2B is a front view thereof, FIG. 2C is a bottom view thereof, and FIG. 2D is a top view thereof. Is shown. FIG. 3 shows a more detailed configuration of a region including the thermal head 2 and the foamed portion 4 in FIG. In FIG. 2, the thermal head 2 has a substantially rectangular parallelepiped shape as a whole, and a bottom surface side thereof is, for example, a heat generating substrate 2a made of ceramic, and an opposing upper surface side is a heat dissipation substrate 2 made of, for example, aluminum which functions as a heat sink.
b. A plurality of heating resistors 50 are provided in a line on one end surface of the thermal head 2 on the heating substrate 2a side. The heating resistors 50 are linearly arranged at a density of, for example, 8 dots / mm, and are drawn as one straight line in FIG.

As shown in FIG. 3, a thermal transfer ribbon 6 for Braille
The platen roller 20 is arranged so as to face the plurality of heating resistors 50 so as to sandwich the paper 5. Also,
The surface of the heating resistor 50 can be pressed almost uniformly along the surface of the platen roller 20 so that the heating resistor 50 can press the paper 5 guided by the braille thermal transfer ribbon 6 and the paper guide 72 with a substantially uniform force. Thus, the thermal head 2 can be pressed from the heat radiation substrate 2b side by a pressing member (not shown).

Each of the plurality of heating resistors 50 passes through the inside of the housing of the thermal head 2 and is electrically connected to a corresponding connector terminal 70 provided at the other end, and is not shown. By applying a voltage based on print data from the control device to a predetermined connector terminal 70, a desired heating resistor 50 can be heated to a desired temperature. On the top surface of one end of the thermal head 2 opposite to the bottom surface of the heating resistor 50, for example, three concave portions 52, 54, 56 are arranged substantially evenly along the arrangement direction of the heating resistor 50. It has been formed.

Heaters 60, 62, and 64 are attached to the recesses 52, 54, and 56, respectively. These heaters 60, 62, 64 are provided by the thermal head 2.
At least in the vicinity of the heating resistor 50, for example, 40 °
It is provided for heating (preheating) to C to 60 ° C. to keep the temperature. These heaters 60, 62, 64 also pass through the inside of the housing of the thermal head 2 and connect to the connector terminals 7 at the other end.
0, and generates heat to a desired temperature by a command from a control device (not shown), so that the tip of the thermal head 2 can be kept at a desired temperature. Thus, at the time of printing, the thermal expansion ink layer 6d of the braille thermal transfer ribbon 6 facing the plurality of heating resistors 50 at the tip of the thermal head 2 can be preheated to maintain a predetermined temperature. It has become.

Next, the structure of the foaming section 4 of the Braille printer according to the present embodiment will be described in more detail with reference to FIG. A paper guide 74 is provided in a substantially vertical direction on the paper transport direction side of the platen roller 20 and the transport roller 21, and a paper guide 74 in front of the transport rollers 22 a and 22 b (not shown in FIG. 3) provided in the middle thereof. The end portion is provided to be bent in a predetermined arc shape so as to guide the sheet 5 in the horizontal direction. A foaming section 4 is provided in front of the end of the paper guide 74 via a guide roller 24. Foam part 4
The preheat section 40 is provided with a heat radiating surface 40a facing the back side of the sheet 5 so as to heat the thermally expandable ink layer 6d of the transfer section from the back side of the conveyed sheet 5. The preheating section 40 is provided to preliminarily apply heat to the thermally expandable ink layer 6d prior to heating in the heating section 42 so that the thermally expandable ink layer 6d is not rapidly heated. A heating section 42 is provided on the side of the preheating section 40 in the sheet transport direction so as to partially overlap the preheating section 40. The heat section 42 is arranged with the heat radiating surface 42a facing the front side of the paper 5 so as to heat the thermally expandable ink layer 6d of the transfer section from the front side of the conveyed paper 5.

The heat dissipating surface 42a of the heat unit 42 is located at a position facing the heat dissipating surface 42a of the heat unit 42 with a predetermined gap.
A paper suction fan 44 for sucking the paper 5 passing through the vicinity from the back surface is arranged. Paper 5 with paper suction fan 44
By sucking the back surface, the heat radiating surface 42
a is prevented from directly contacting the paper 5 to press the transfer portion, and the distance between the heat radiating surface 42a and each transfer portion is kept constant so that the thermally expandable ink layer 6 can be maintained at a substantially uniform temperature.
d can be heated. For this reason, the paper suction fan 4
Reference numeral 4 has a suction port 44a for sucking the sheet 5 from the rear side of the sheet 5 that has been conveyed. The width of the gap between the heat radiating surface 40a of the preheating portion 40 and the heat radiating surface 42a of the heating portion 42 in the thickness direction of the paper 5 and the width of the gap between the heat radiating surface 42a of the heating portion 42 and the suction port 44a of the paper suction fan 44. Is about 3 mm. The paper 5 having entered the foaming section 4 is preliminarily heated by the preheating section 40 while being transported, and further heated by the heating section 42 while being suctioned from the back surface by the paper suction fan 44.
And the thermal expansion ink layer 6d of the transfer portion on the paper 5
Can be foamed to a height of about 0.3 to 0.4 mm. It takes several seconds for the paper 5 that has entered the preheating unit 40 to pass through the heating unit 42 and be discharged, and within this heating time, the thermally expandable ink layer 6d of the transfer unit is gradually heated, and finally 80 ° C to 15 ° C
The temperature control of the preheating unit 40 and the heating unit 42 is performed so that the temperature becomes about 0 ° C.

Next, the operation of the braille printer according to the present embodiment will be described with reference to FIGS. The thermal transfer ribbon 6 for braille, which is sandwiched together with the paper 5 between the tip of the thermal head 2 and the platen roller 20, is previously supplied from the supply reel 8 to the take-up reel 10 via the tip of the thermal head 2.
Is set to move along with the sheet 5 conveyed with the rotation of the platen roller 20 and the conveying roller 21, to be fed out from the supply reel 8 and wound on the take-up reel 10. Shall be. Also,
Heating heaters 60, 62, and 64 provided on the upper surface side of one end of the thermal head 2 generate heat under the control of a control system (not shown) to heat the front end of the thermal head 2 to 40 ° C.
It is assumed that the temperature is kept at 0 ° C. As a result, the thermal expansion ink layer 6d of the Braille thermal transfer ribbon 6 facing the plurality of heating resistors 50 at the tip of the thermal head 2 is already kept at a predetermined temperature.

In such a state, the paper 5 is carried in from the paper supply section 80 provided above the housing 1. DC for paper removal
By driving the motor 14, a sheet take-out unit (not shown) conveys the head of the sheet 5 from the sheet supply unit 80 into the housing 1. The paper 5 conveyed into the housing 1 is driven by driving rollers 18a and 18b.
The paper 5 is guided by a paper guide unit (not shown), and the position of the front end of the paper 5 is detected by a position detection system such as a photo sensor (not shown).

At this time, since the thermal expansion ink layer 6d of the thermal transfer ribbon 6 for braille has already been heated by the thermal insulation heaters 60, 62 and 64 at the tip of the thermal head 2 as described above, the control system is immediately started. The printing operation can be shifted to, and a predetermined voltage based on the printing data is applied to each heating resistor 50 of the thermal head 2 to start printing. Thereafter, the paper 5 and the Braille thermal transfer ribbon 6 sandwiched between the tip of the thermal head 2 and the platen roller 20 move along with the rotation of the platen roller 20 and the transport roller 21 to generate each heat based on the print data. Transfer portions are sequentially formed on the surface of the sheet 5 by the heat generated by the resistors 50. At this time, the thermal head 2 itself is heated to 40 ° C. to 60 ° C., which is lower than the temperature at which the heat generating resistor 50 of the thermal head 2 generates heat, to maintain the heat, and the heat generated by the heat retaining temperature is transferred to the thermally expandable ink layer 6d. Therefore, the transfer portion and the non-transfer portion can be easily separated from each other.

As described above, according to the present embodiment, since the thermal head 2 is controlled to be maintained at a predetermined temperature, the heat of the thermal head 2 is used to make the film-like transparent substrate of the thermal transfer ribbon 6 for Braille. It is possible to easily separate the non-transfer portion wound up together with the material 6b from the transfer portion transferred to the sheet 5. Therefore, according to the Braille printer of the present embodiment, even if the thickness of the thermal expansion ink layer 6d in the transfer section is large, separation from the thermal expansion ink layer 6d in the non-transfer section wound up together with the base material 6b. The heat-expandable ink layer 6d is peeled off from the heat-sensitive adhesive layer 6e adhered to the paper 5 and wound up together with the base material 6b,
There is no possibility that the heat-sensitive adhesive layer 6e once adhered is peeled off together with the base material 6b from the paper 5 together with the paper fibers. At this stage, the thermally expandable ink layer 6d of the transfer portion transferred to the surface of the paper 5 has not yet foamed, and is sent to the foaming portion 4 provided in the next stage to foam. With the printing operation by the thermal head 2, the transport roller 21 and the platen roller 20 are rotated by the driving of the paper transport pulse motor 12, and the paper 5 which is guided and moved by the paper guide 74 is transported to the foaming section 4.

The paper 5 conveyed in the foaming section 4 is first heated by the preheating section 40 so as to gradually increase the temperature of the thermally expandable ink layer 6d of the transfer section from the back of the paper 5. This makes it possible to preliminarily apply heat to the heat-expandable ink layer 6d prior to heating in the heating section 42 in the next stage. Next, the paper suction fan 44 sucks the paper 5 from the back side of the paper so that the moving paper 5 does not contact the heat radiating surface 42 a of the heating part 42.
In step 2, the thermally expandable ink layer 6d in the transfer section is heated from the front side of the paper 5. Thus, the thermally expandable ink layer 6d at the transfer portion on the paper 5 can be stably foamed to a height of about 0.3 to 0.4 mm. Thereafter, the sheet 5 is conveyed while being sandwiched between the rotating conveying rollers 26a and 26b,
It is discharged from the housing 1.

As described above, in the foaming section 4 of the Braille printer according to the present embodiment, the preheating section 40 for heating from the back surface of the paper 5 is provided before the heating section 42 for heating the thermally expandable ink layer 6d from the surface of the paper 5. Thus, a certain amount of heat is preliminarily applied to the thermally expandable ink layer 6d, so that the thermally expandable ink 6d is not suddenly heated. Accordingly, it is possible to obtain a high-quality Braille of a desired height and shape without causing foaming to end without foaming only in the surface portion of the heat-expandable ink layer 6d and sufficiently expanding the ink inside. become.

Further, since the paper suction fan 44 is provided as a suction mechanism for sucking the paper 5 passing through the heating unit 42 from the back surface, the heat radiation surface 42a of the heating unit 42 is directly
The thermal expansion ink layer 6d can be heated at a substantially uniform temperature while keeping the distance between the heat radiating surface 42a and each of the transfer portions constant without pressing the transfer portion by contact with the heat transfer surface 42a. This makes it possible to produce high-quality Braille with a uniform height and a compact and highly efficient heating device.

Further, in the Braille printer according to the present embodiment, the size of the print dots can be changed based on the print data, so that not only Braille but also Braille diagrams and patterns can be easily drawn. Can be. In addition, plain paper can be used, and since there is no dent on the back of the paper as in the dot impact method, it is flat, so characters and pictures for people who can see are printed on the back of the paper. It is possible.

The present invention is not limited to the above embodiment, but can be variously modified. For example, the Braille printer in the above-described embodiment forms a paper transport path close to the vertical direction. However, the present invention is not limited to this, and a Braille printer having a configuration in which paper is transported in a substantially horizontal direction is applicable. This may be, of course, and is not limited at all by the paper transport path.

Further, in the above embodiment, as the means for keeping the thermal head 2 warm, the heaters 60, 6 for keeping the temperature are provided in the concave portions 52, 54, 56 on the upper surface of one end of the thermal head 2.
2 and 64, these heaters 60, 6
The tip of the thermal head 2 is heated at 2 and 64 to keep the temperature, but the present invention is not limited to this.
The control system may apply a heat-retention voltage lower than the voltage applied at the time of transfer to the respective heating resistors 50 at all times or for a fixed time to keep the tip of the thermal head 2 at a predetermined temperature.

For example, the heating resistor 50 of the thermal head 2 in the above-described embodiment is driven at 24 V DC to obtain a predetermined heating value. Alternatively, it can be controlled so that the temperature is kept constant by applying for a certain time. By doing so, there is an advantage that a thermal head similar to the conventional one can be used without attaching the heaters 60, 62 and 64 to the thermal head 2 as in the above embodiment. Further, in this case, the heat retention voltage is not a DC voltage but, for example, 1 μm.
The pulse voltage may be supplied in a cycle of 10 to 10 μsec. This produces an effect that the power supply as a whole can be suppressed.

Also, in the above-described embodiment, a description has been given by taking a Braille printer that prints Braille on paper as an example.
The present invention is not limited to this, and can be applied to a Braille FAX machine, a Braille copying machine, and the like.

[0045]

As described above, according to the present invention, thermal transfer of an ink ribbon having a relatively large thickness can be easily and reliably performed. Further, according to the present invention, since the temperature of the thermal head is kept at a predetermined temperature, the ink ribbon can be preheated, and the non-printing portion (non-transfer portion) remaining on the ribbon and the ribbon can be removed. This facilitates the separation from the separated printing portion (transfer portion) and allows the printing to be started immediately. Further, according to the present invention, it is possible to realize a thermal transfer type Braille printer capable of producing Braille with clear and excellent print quality.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a schematic configuration of a Braille printer according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic configuration of a thermal head of the Braille printer according to the embodiment of the present invention;

FIG. 3 is a diagram illustrating a schematic configuration of a foaming unit of the Braille printer according to the embodiment of the present invention;

FIG. 4 is a diagram for explaining the operation of the proposed Braille printer.

FIG. 5 is a view showing a structure of a thermal transfer ribbon for Braille.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 housing 2 thermal head 4 foaming section 5 paper 6 thermal transfer ribbon for Braille 6a heat-resistant lubricating layer 6b film-like transparent base material 6c release layer 6d thermally expandable ink layer 6e heat-sensitive adhesive layer 8 supply reel 10 take-up reel 12 paper Pulse motor for conveyance 14 DC motor for paper removal 16 Pulse motor control system for paper conveyance and ribbon drive 18a, 18b, 21, 22a, 22b, 26a, 26
b Conveyance Roller 20 Platen Roller 24, 28, 30 Guide Roller 40 Preheating Section 42 Heating Section 42a Heat Dissipating Surface 44 Paper Suction Fan 44a Heat Dissipating Surface 50 Heating Resistor 52, 54, 56 Concave 60, 62, 64 Heating Heater 70 Connector Terminal 72, 74 Paper guide 80 Paper feed section 100 Thermal head 102 Foaming section 104a, 104b Guide roller 106 Platen roller 108a, 108b Drive roller 110 Transfer section 112 Braille

Claims (7)

[Claims] 1. A plurality of heating resistors arranged in a straight line, and a predetermined heating resistor is heated to heat a predetermined region of a thermal transfer ribbon for Braille coated with a thermally expandable ink. In a Braille printer having a thermal head for transferring the thermally expandable ink in the predetermined area to a paper surface, and a foaming unit for heating and foaming the transferred thermally expandable ink, the thermal expansion may be performed via the thermal head. A braille printer further comprising a heat retaining means for keeping the volatile ink at a predetermined temperature. 2. A Braille printer according to claim 1, wherein said heat retaining means has a heating mechanism for heating said thermal head. 3. The Braille printer according to claim 1, wherein said thermal insulation means applies a thermal insulation voltage lower than a voltage applied at the time of transfer to said plurality of heating resistors to cause said thermal head to move to a predetermined temperature. A Braille printer characterized by keeping it at a temperature. 4. The Braille printer according to claim 3, wherein the heat retaining voltage is a pulse voltage. 5. A plurality of heating resistors arranged in a straight line, and a predetermined heating resistor is heated to heat a predetermined area of a thermal transfer ribbon for Braille coated with a thermal expansion ink. In a Braille printer having a thermal head for transferring the thermally expandable ink in the predetermined area to the surface of a sheet and a foaming section for heating the transferred thermally expandable ink to foam the foamed section, A heating unit for heating the thermally expandable ink, provided before the heating unit,
A braille printer comprising: a preheating unit for heating from the back side of the paper. 6. The Braille printer according to claim 5, wherein said foaming section has a suction mechanism for sucking said paper passing through said heating section from the back side. 7. A thermal transfer printing method for heating a predetermined area of a thermal transfer ribbon for braille coated with a thermally expandable ink and transferring the thermal expandable ink in the predetermined area to the surface of paper, A thermal transfer printing method, wherein the thermal expandable ink is kept at a predetermined temperature so that the thermal expandable ink in the predetermined area is easily separated from the thermal transfer ribbon.