JPH11291530A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an accumulated temperature on a substrate of a thermal head uniform in a short time and to eliminate a problem of a thermal inclination which may influence the recording result by a method wherein a buffer substrate having a good thermal conductivity is interposed between the thermal head and a head fixing base. SOLUTION: A thermal head 7 is adhered to be fixed to a head fixing base 9 through a buffer substrate 10. The head fixing base 9 is provided to one end of a head pressing lever which is pivoted to a reciprocatable carriage. It is markedly preferable to use an Si substrate as the buffer substrate 10. A silicon-based adhesive having a good thermal conductivity is used for the adhering of a portion between the thermal 7 and buffer substrate 10 and a portion between the buffer substrate 10 and head fixing base 9. A plurality of heat-radiating fins 11 are formed at the rear face of the head fixing base 9. The fins 11 are provided such that they are symmetric with respect to a center axis which divides a whole of a heating section 8 into two parts, thereby improving quick and uniform radiating effects in the heating section 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer, and more particularly to a thermal printer suitable for applying high energy to a heat generating portion of a thermal head such as thermal sublimation transfer recording.

[0002]

2. Description of the Related Art A thermal printer that performs thermal transfer type or thermal type recording performs recording on recording paper by heat generated by a thermal head. Of these, when recording is performed using an ink ribbon, generally, a sheet is supported in front of a platen, and a thermal head having a plurality of heating elements is mounted on a carriage, and these thermal heads and the platen are generally mounted. In the meantime, an ink ribbon as an example of an ink film in which a desired ink is applied to a base film and the paper are sandwiched, and while moving a thermal head along with a platen along with a carriage, the ink ribbon is paid out, and the thermal ribbon is fed out. The ink of the ink ribbon is partially transferred to a sheet by selectively applying a current that is an energy based on the recording information to the plurality of heating elements of the head to selectively cause the heating elements to generate heat. An image such as a character is recorded. Also, when performing thermal recording, thermal recording paper is used as the paper, and without using an ink ribbon, the thermal recording paper is colored by the heat generated by the heating element in the same manner as thermal transfer recording. I have.

[0003] Such a thermal printer is widely used as an output device of a computer, a word processor or the like because of high recording quality, low noise, low cost, and ease of maintenance.

Among the thermal printers described above, a thermal transfer type printer uses a heat-fusible ink ribbon (hereinafter referred to as a hot-melt ink ribbon) formed by applying a hot-melt ink to a base film such as a plastic film. In addition to those that perform recording on a sheet, those that perform recording on paper using an ink ribbon in which a heat sublimation ink is applied to a base film (hereinafter, referred to as a heat sublimation ink ribbon) are also known.

[0005] Among these, a thermal printer (hereinafter, referred to as a hot-melt printer) that records on paper using a hot-melt ink ribbon can record on a wide variety of paper such as plain paper, cardboard, and postcards. It is easy to use and excellent. In a thermal printer (hereinafter, referred to as a thermal sublimation printer) that performs recording on paper using a thermal sublimation ink ribbon, the amount of sublimation of the thermal sublimation ink is controlled by controlling the energy applied to the thermal head. By adjusting the amount of ink transferred to the paper and adjusting the density of the recorded image on the paper, it is possible to adjust the density of the recorded image on the paper. A recorded image can be obtained. For this reason, thermal sublimation printers have recently been widely used as high-quality video printers and the like.

In general, when a high-density recorded image is obtained in a thermal sublimation type printer, the energy applied to the heat generating element of the thermal head needs to be several times the energy applied to the heat melting type printer. . Therefore, in the thermal sublimation type printer, a carriage on which the thermal head is mounted is caused to travel at a speed of about 1/5 of a traveling speed of the carriage of the thermal melting type printer, so that a large energy is applied to the heating element of the thermal head. Is provided.

However, a large amount of energy for heat generation in the thermal sublimation type printer is easily stored in the thermal head, and the heat storage may have an effect on subsequent thermal sublimation printing such as ink smearing and density change.

Therefore, conventionally, means for releasing the heat stored in the thermal head by, for example, disposing a heat sink on the back side of the thermal head mounting base on which the substrate of the thermal head is mounted is adopted.

[0009]

However, as described above, the heat generating element selectively generates heat based on the recorded information. In other words, the thermal head is completely different from the portion that generates heat by the recorded information. A portion that does not generate heat will be mixed. In view of the thermal head as a whole, even though the heat storage can be dissipated by the heat sink, the heat generating part and the non-heat generating part of the thermal head, the part where the heat sink is provided and the part where the heat sink is not provided In this case, a temperature difference occurs in the heat storage remaining after a short period of heat radiation, which also has a great effect on the subsequent recording result.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a thermal printer which can equalize the heat storage temperature of a thermal head on a thermal head substrate in a short period of time and can eliminate the problem of a thermal gradient. It is intended to provide.

[0011]

In order to achieve the above object, a thermal printer according to the present invention has a head mounting base for fixing a thermal head in which a plurality of heating elements are arranged and arranged, and the head mounting base is mounted. A thermal printer that presses the thermal head against the platen via a recording sheet while selectively reciprocating the carriage that moves along the platen, and selectively applies energy to the heating element to perform recording on the recording sheet. The thermal printer according to claim 2, wherein a buffer substrate having good thermal conductivity is interposed between the head mount and the thermal head. The buffer substrate is a Si substrate.

According to these inventions, the heat applied to the thermal head can be made uniform by the buffer substrate. In particular, by using the Si substrate, the heat can be made uniform under high thermal conductivity. be able to.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS.

FIG. 1 shows an embodiment of the present invention in which both types of ink ribbons of a heat sublimation ink ribbon and a heat melting ink ribbon can be selectively used.
In the thermal printer 1 of the present embodiment shown in FIG. 1, a flat platen 2 is disposed at a desired position on a frame (not shown) so that its recording surface 2a is substantially vertical. A guide shaft 3 is provided below the front side in parallel with the platen 2. At an appropriate position of the guide shaft 3, the carriage 4 divided vertically
Is attached, and one carriage 4 shown below is
A lower carriage 4a attached to the guide shaft 3 is provided. The other carriage 4 shown above has a lower cassette 4a to which a ribbon cassette 5 described later is attached.
The upper carriage 4b is configured to be able to move up and down in the vertical direction.

The carriage 4 drives a suitable drive belt 6 wound around a pair of pulleys (not shown) by a carriage motor (not shown) so as to be reciprocally movable along the guide shaft 3. It is supposed to be. The carriage 4 can select one of two stages of moving speed, high speed and low speed, by controlling the rotation speed of the carriage motor by a control unit 29 described later.

The carriage 4 can be moved toward and away from the platen 2 by a well-known head moving mechanism (both not shown) facing the platen 2 and operable with the driving force of a drive motor. A thermal head 7 for recording on a recording paper (not shown) on the platen 2 in a pressure contact state (head down state) in contact with the thermal head 7 is provided. The thermal head 7 is provided with a heating section 8 in which a plurality of heating elements are arranged and arranged. The heating section 8 generates heat based on desired recording information input by a suitable input device (not shown) such as a keyboard. The element is selectively heated.

FIGS. 4 and 5 show the main structure of the thermal head 7 according to the present embodiment. The thermal head 7 is substantially L-shaped and attached to the carriage 4 so as to be swingable about a support shaft. It is adhesively fixed via a buffer substrate 10 to a head mounting base 9 provided at one end of a head-shaped pressure contact lever (not shown). That is,
In this embodiment, as shown in FIG. 5, the thermal head 7 is bonded to a buffer substrate 10, and is fixed by bonding the buffer substrate 10 to a head mount 9. As the buffer substrate 10, a Si substrate is used in the present embodiment. Alternatively, a metal substrate having good thermal conductivity may be used.
In this embodiment, the thermal head 7 and the buffer substrate 10, and the buffer substrate 10 and the head mount 9
For bonding to the substrate, a silicon-based adhesive having good heat conductivity is used. For example, Shin-Etsu silicone adhesive KE349
3 can be used. The adhesive has a thermal conductivity of about 1.7 W / m ° C.

A plurality of radiating fins 11 are formed on the back of the surface of the head mounting base 9 to which the thermal head 7 is fixed, at a position directly below the heat generating portion 8. It is designed to rapidly dissipate heat storage.
The head mounting base 9 has a 5-5 axis (heating section 8) shown in FIG.
Is set as a plane of symmetry with respect to (the axis that bisects the whole), and the shape is symmetric. That is, the volume of each half of the head mounting base 9 on both sides of the 5-5 axis is made equal. With this structure, the heat stored in the heat generating portion 8 can be released in a well-balanced manner.

Further, the head mount 9 is provided with a heat generating portion 8.
Materials with high thermal conductivity to improve the heat dissipation efficiency of
For example, it is formed of Al die cast, pure Al, Cu (copper), or the like. These thermal conductivities were 96 W / m ° C. for Al die cast, and 238 W for pure Al.
/ M ° C and Cu is 385 W / m ° C. In the present embodiment, the head mount 9 is formed by Al die casting in consideration of easiness of processing and low cost.

The thermal head 7 can be controlled by a control unit 29 described later to select either a strong pressure contact or a weak pressure contact with the platen 2 and to apply additional energy to the thermal head 7. Large and small 2
Either of two stages (specifically, two stages of a long time and a short period of time for energizing the heat generating unit 8) can be selected.

The carriage 4 will be described in more detail. The upper carriage 4b, which is substantially parallel to the lower carriage 4a, is brought into contact with and separated from the lower carriage 4a by a parallel crank mechanism 12 on the upper surface of the lower carriage 4a. It is configured to be freely movable in parallel. As shown in FIG. 3, the parallel crank mechanism 12 is provided at a pair of left and right ends of the carriage 4 and intersects each other in an X shape.
It has a pair of links 13a, 13b, the intersection of these links 13a, 13b is pivotally connected by a pin 14a, and the ends of the links 13a, 13b are pins 14b, 14b.
The lower carriage 4a and the upper carriage 4b are slidably locked in long holes (not shown) formed at the upper ends of the right and left sides of the lower carriage 4a and the upper carriage 4b by c, 14d, and 14e, respectively.

The lower carriage 4a is provided with a rotary crank mechanism 15, and the rotary crank mechanism 15 allows the upper carriage 4b to be moved in parallel. This rotary crank mechanism 15
A rotating plate 16 serving as a rotating member supported so as to be rotatable and driven by the lower carriage 4a, and a connecting link 18 serving as a connecting member pivotally connected to an eccentric position of the rotating plate 16 by a pin 17a. The front end 18 is pivotally connected to the upper carriage 4b by a pin 17b.
The rotating plate 16 is driven to rotate by a suitable driving means (not shown) such as a motor.

Returning to FIG. 1, a plate-like arm is formed on each of the left and right sides of the upper carriage 4b as an engaging portion 19a having a tip gently curved inward and a projection formed at the upper and lower ends. Reference numerals 19 stand upright at intervals substantially equal to the width of the ribbon cassette 5. At the center of the upper carriage 4b, a pair of rotatable bobbins 20 are disposed at predetermined intervals from each other so as to protrude upward.
The bobbin 20 allows the ink ribbon 21 to travel in a predetermined direction. One of the pair of bobbins 20 is a take-up bobbin 20 a for winding the ink ribbon 21, and the other is a delivery bobbin 20 for sending the ink ribbon 21.
b.

An optical sensor 22a is provided on the edge of the carriage 4 farther from the platen 2 as a sensor 22 for detecting the type of the ink ribbon 21 stored in the ribbon cassette 5. . In this embodiment, a reflection-type optical sensor is used as the optical sensor 22a. The optical sensor 22a is connected to a control unit 29 that controls a recording operation and the like of the thermal printer 1 disposed at a desired position of the thermal printer 1.

As shown in FIGS. 1 and 2, above the carriage 4, there is provided a substantially plate which is supported by a frame (not shown) at an appropriate interval so as to be openable and closable as shown by a double arrow A in FIG. A canopy 23 is provided. The canopy 23 functions as a paper presser on the exit side of a paper feed mechanism (not shown) in the closed state, and is disposed so as to face the carriage 4. The length is almost the same.

A plurality of cassette holders (not shown) for holding the ribbon cassette 5 are provided at predetermined positions on the lower surface of the canopy 23 facing the carriage 4 in parallel. In the embodiment, a ribbon cassette 5a in which an ink ribbon (a heat-meltable ink ribbon) 21a coated with a heat-meltable ink is housed, and an ink ribbon (heat-sublimable ink ribbon) coated with a heat-sublimable ink. ) 21b are arranged in a line in the moving direction of the carriage 4 with the ribbon cassette 5b in which the ribbon cassette 5b is housed. Each of the ribbon cassettes 5a and 5b is selected between the canopy 23 and the upper carriage 4b by the operation of the parallel crank mechanism 12 operating with the rotary crank mechanism 15, as indicated by the double-headed arrow B in FIG. The delivery is done in a regular manner.

The cassette holder may hold a ribbon cassette 5a containing the heat-meltable ink ribbon 21a or a ribbon cassette 5b containing the sublimable ink ribbon 21b.

Each of the ribbon cassettes 5a, 5 of the present embodiment
b is formed in the same shape and the same size irrespective of the type of the ink ribbon 21, and is rotatably supported (not shown) in a pair of upper and lower planar substantially rectangular case bodies 24. A pair of reels, a pair of rotatably supported ribbon feed rollers, a plurality of guide rollers facing the rotatably supported ribbon path, and the like are provided.

Then, the ink ribbon 2 is placed between a pair of reels.
1 is wound, and an intermediate portion of the ink ribbon 21 is led out. When the ribbon cassette 5 is mounted on the upper carriage 4b, one of the pair of reels is a take-up reel that winds a portion of the ink ribbon 21 used for recording, and the other sends out the ink ribbon. It is a sending reel. On the inner peripheral surface of each reel, a plurality of key grooves are formed in a spline shape at intervals in the circumferential direction, and the inner peripheral surface of the take-up reel is formed by the winding bobbin 20a.
Is formed into a take-up hole 25a, and an inner peripheral surface of the delivery reel is provided with a delivery hole 25b with which the delivery bobbin 20b is engaged.
It has been. The carriage 4 of the ribbon cassette 5
A concave portion 26 facing the thermal head 7 is formed on a surface facing the platen 2 in a state where the ink ribbon 21 is mounted on the intermediate portion of the ink ribbon 21.

An identification mark 27 for discriminating the type of the ink ribbon 21 stored in each ribbon cassette 5 is provided on the rear surface of the ribbon cassette 5 extending parallel to the surface on which the concave portion 26 is formed. Are located. The identification mark 27 of the present embodiment is formed by a reflective seal 28 having a different number of striped non-reflective portions 28a depending on the type of the ink ribbon 21.

The identification mark 27 is provided on the carriage 4 by an optical sensor 22 as a cassette type detecting means.
a, and this detection signal is sent to the controller 2
9 and counts the number of identification marks 27 in each ribbon cassette 5 in the control section 29 to thereby control the ink ribbons 21 stored in the ribbon cassette 5.
Is determined.

That is, in the ribbon cassette 5a shown on the left side in FIG. 1, a reflective seal 28A having four non-reflection portions 28a is arranged as the identification mark 27, and the ribbon cassette 5b shown on the right side in FIG. , A reflection seal 28 </ b> B having two non-reflection portions 28 a is arranged as the identification mark 27. And the ribbon cassette 5
1 is a reference position BP for detecting the identification mark 27, and the left end of the rear surface shown on the near side in FIG.
7, the distance L to the right end face of the non-reflection portion 28a located at the right end is the same for all the identification marks 27, and a desired distance L for identifying the type of the ink ribbon 21 within this distance L. The non-reflection part 28a is formed. The identification mark 27 can identify the color of the ink ribbon 21 as well as the type of the ink ribbon 21 stored in the ribbon cassette 5. The carriage 4 can be stopped when the optical sensor 22a detects the identification mark 27 to be used. When the carriage 4 is stopped, the ribbon cassette 5 stored in the cassette holder is moved to the upper carriage 4
b.

The identification mark 27 may be printed on the ribbon cassette 5, and is not particularly limited to the configuration of the present embodiment.

The lower carriage 4a, which is reciprocally movable along the platen 2, has a stepping motor for winding the thermal head 7 into and out of the platen 2 and a winding of the ink ribbon. A stepping motor (hereinafter, referred to as a ribbon take-up motor) for take-up control is provided (neither is shown), and power is supplied to the thermal head 7 and the take-up bobbin 20a via a transmission gear (not shown). It is designed to communicate.

The control unit 29 includes a memory (not shown)
As shown in FIG. 6, based on a mode signal sent from a mode changeover switch 30 disposed at a desired position of a frame (not shown), at least a heat-meltable ink ribbon is formed. It is determined whether the recording mode is a first recording mode in which recording is performed on a recording sheet such as plain paper by using thermal fusion transfer using the heat transfer sublimation 21a or a second recording mode in which recording is performed by thermal sublimation transfer onto dedicated paper using the heat sublimation ink ribbon 21b. Based on the mode discrimination unit 31 and the discrimination result of the mode discrimination unit 31, the rotation speed of the carriage motor and the ribbon take-up motor, the energization time to the thermal head 7, the pressing force of the thermal head 7 on the platen 2, the ribbon cassette 5, etc. Has a first recording mode control unit 32 and a second recording mode control unit 33 for controlling the recording mode corresponding to each mode.

Note that the control unit 29 is based on an output signal from the optical sensor 22a accompanying the movement of the carriage 4,
The presence or absence of the ribbon cassette 5, the type of the ink ribbon 21 stored in the ribbon cassette 5, the moving distance of the carriage 4 with respect to the home position, the open / close state of the canopy 23, the distance between the ribbon cassettes 5, and the like are determined or detected. I have.

The rotation speeds of the carriage motor and the ribbon take-up motor are controlled by the optical sensor 22a.
Of the ink ribbon 2 in the ribbon cassette 5 according to the detection result of
Although control is performed based on whether the ink ribbon 21 is the heat-meltable ink ribbon 21a or the heat-sublimable ink ribbon 21b, the present invention is not limited to this, and the control may be performed based on other factors.

For example, a recording medium detecting means (not shown) for detecting the type of the recording medium (recording paper) is provided, and the detection result is input to the control unit 29. When the recording medium is plain paper, the control unit 29 controls the rotation speed of the carriage motor and the ribbon take-up motor in the first recording mode based on the detection result. In the case of paper, the rotation speed of each motor may be controlled in the second recording mode.

A recording speed detecting means (not shown) for detecting the recording speed of the carriage 4 is provided, and the result of the detection is inputted to the control unit 29. 29 may control the rotation speed of the carriage motor and the ribbon take-up motor. For example, when the recording speed by the carriage 4 is higher than a predetermined recording speed, control is performed in a first recording mode, and when the recording speed is lower than the predetermined recording speed, control is performed in a second recording mode. Is also good.

Further, a selection switch 34 is provided as selection means for manually or automatically selecting at least one condition such as a type of the ribbon cassette 5 to be used, a recording mode, a recording medium and a recording speed. You may make it connect with the control part 29.

Alternatively, various conditions such as the type of the ribbon cassette may be inputted and selected from an external device such as a computer to which the thermal printer is connected.
In particular, when the ribbon cassette 5, recording mode, recording medium, or recording speed is arbitrarily selected by an external device,
A necessary mode may be selected on a display screen of a CRT or the like, and the result may be input to the control unit 29 via an interface.

Next, the operation of the present embodiment having the above-described configuration will be described.

The operation of driving the thermal printer 1 of the present embodiment and selecting the recording mode so as to meet the purpose of recording is performed automatically or by the operator operating the mode changeover switch 30 to set the thermal mode. A first recording mode in which recording is performed by thermal fusion transfer on recording paper such as plain paper using the fusible ink ribbon 21a, or a second recording mode in which recording is performed by thermal sublimation transfer on dedicated paper using the thermal sublimation ink ribbon 21b. This is performed by selecting one of the above.

When a recording mode selection operation is performed, a mode signal corresponding to one of the selected modes is transmitted from the mode changeover switch 30 to the control unit 29, and the mode determination unit of the control unit 29 31 determines whether the mode signal sent from the mode changeover switch 30 is the first recording mode or the second recording mode, and selects one of the first recording mode control unit 32 and the second recording mode control unit 33 based on the determination result. One of them is operated, and the selection operation of the ribbon cassette 5 containing the ink ribbon 21 having the heat-meltable ink or the heat-sublimable ink corresponding to one of the first recording mode and the second recording mode is started.

Then, the carriage 4 located at the home position is moved (runs) by a command from the control unit 29 (specifically, one of the first recording mode control unit 32 and the second recording mode control unit 33). Then, the optical sensor 22a disposed on the carriage 4 detects the identification mark 27 of the ribbon cassette 5. Then, the optical sensor 22a
A unique detection signal of each identification mark 27 based on the arrangement and pitch of the non-reflecting portions 28a is sent to the control unit 29, and it is determined whether or not the identification mark 27 corresponds to the command issued by the control unit 29. In the case of the identification mark 27 corresponding to the instruction, the movement of the carriage 4 is stopped. When the identification mark 27 does not correspond to the instruction, the movement of the carriage 4 is continued until the identification mark 27 corresponding to the instruction is detected. That is, in the present embodiment, by detecting a difference in the reflection seal 28 of the ribbon cassette 5 depending on the type of the ink ribbon 21, the ribbon cassette 5 is detected.
(Specifically, the ink ribbon 21) can be reliably determined.

In the present embodiment, since each ribbon cassette 5 is attached to a predetermined position of the canopy 23, the distance from the home position of the carriage 4 to the identification mark 27 of each ribbon cassette 5 is fixed. In addition, the moving distance of the carriage 4 with respect to the home position can be easily detected. In other words, by counting the number of steps of the carriage motor that drives the carriage 4, the moving distance of the carriage 4 with respect to the home position can be easily detected, and the home position can be easily detected.

The number of steps of the carriage motor corresponding to the distance from the predetermined home position to the identification mark 27 of each ribbon cassette 5 and the actual number of steps of the carriage motor when the carriage 4 is driven are determined. Can be detected to detect a change in the thermal printer 1 due to a temperature change such as a change in the distance between the home position and the ribbon cassette 5 and a change in the distance between the ribbon cassettes 5.

Also, since the ribbon cassette 5 in the present embodiment is attached to a predetermined position of the canopy 23, when the canopy 23 is opened, the identification mark 27 of the ribbon cassette 5 is As a result, even if the carriage 4 is scanned,
Identification mark 2 of ribbon cassette 5 by optical sensor 22a
7 cannot be detected. Using this, the open / closed state of the canopy 23 can be detected.

As described above, according to the thermal printer 1 of the present embodiment, the detection of the presence / absence and type of the ribbon cassette 5, the detection of the home position, the detection of the open / closed state of the canopy 23, and the like are performed by one sensor 22. , The cost can be reduced as a whole.

Then, the ribbon cassette 5 in which the ink ribbon 21 corresponding to the selected recording mode is stored.
Are the parallel crank mechanism 12 and the rotary crank mechanism 15
As a result, as shown by a double arrow B in FIG.
3 and selectively transferred between the upper carriage 4b,
The ribbon cassette 5 is mounted on the carriage 4 and the operation of selecting the ribbon cassette 5 ends.

Next, the recording paper corresponding to the selected recording mode is set between the platen 2 and the thermal head 7 manually or by a paper feeding device (not shown), and the recording operation is started.

In the case of the first recording mode, a command from the first recording mode control unit 32 of the control unit 29 causes
In the head down state, the pressing force of the thermal head 7 against the platen 2 is about 0.5 to 3.0 kg, the moving speed of the carriage 4 corresponding to the recording speed by the thermal head 7 is about 10 to 50 cm / sec,
The energizing time per dot of the heating section 8 is 0.1 ms.
The control is performed such that the temperature of the heat generating portion 8 is raised to 600 ° C. by one-pulse energization when the energization time elapses. Further, the take-up speed of the take-up bobbin 20a is set to be equal to or about 105% of the moving speed of the carriage 4, and the timing of taking up the hot-melt ink ribbon 21a is controlled by the carriage 4 so that the hot peeling can be performed. Perform almost simultaneously with recording. This makes it possible to reliably perform recording by thermal fusion transfer on recording paper such as plain paper using the thermal fusion ink ribbon 21a.

In the second recording mode, the pressing force of the thermal head 7 against the platen 2 in the head down state is smaller than that in the first recording mode in accordance with a command from the second recording mode controller 33 of the controller 29. 0.2 ~
The moving speed of the carriage 4 on which the thermal head 7 is mounted is set to about 1.5 kg,
The same pulse P is applied five times per dot to the heating unit 8 of the thermal head 7 by dividing the energization per dot by about 5 cm / sec.
Is repeated to control the temperature of the heat generating portion 8 to rise to 650 ° C. when the energization time of 0.8 msec has elapsed. Further, the take-up speed of the take-up bobbin 20a is set to be about 80 to 95% lower than the moving speed of the carriage 4, and the timing at which the heat sublimation ink ribbon 21a is taken up is such that the peeling can be performed in a cold state. This is performed after the carriage 4 has moved a predetermined amount from the recording start position. This allows
The recording by thermal sublimation transfer can be reliably performed on the recording paper using the thermal sublimation ink ribbon 21b.

As described above, by making the pressure of the thermal head 7 against the platen 2 in the second recording mode weaker than that in the first recording mode, wear of the thermal head 7 in the second recording mode is reduced. By
The overall durability of the thermal head 7 can be reliably improved.

On the other hand, when such recording, especially thermal sublimation transfer recording, is performed, the heat generating portion 8 of the thermal head 7 is used.
Since the energy added to the thermal head 7 is large, the thermal storage is also large.
Since the head mounting base 9 is fixed to a head mounting base 9 formed by die casting, and a plurality of radiating fins 11 are formed on the head mounting base 9 directly below the heat generating portion 8, heat is rapidly stored. Heat can be dissipated.

As a specific effect, the thermal storage of the thermal head 7 was 100 ° C. in the conventional thermal printer, but was reduced to 50 ° C. in half according to the present embodiment. For this reason, it is possible to prevent recording contamination in the non-recording area due to heat storage.

In the case where continuous printing is performed according to the present embodiment, the density change between each page can be reduced to a level that cannot be visually recognized.

Further, when the temperature of the thermal head 7 rises due to heat storage, a conventional thermal printer requires a waiting time of about 20 minutes until the temperature drops to a recordable temperature. According to this, the standby time can be reduced to about 10 minutes, which is half of the conventional one.

The buffer substrate 1 made of Si having good thermal conductivity is provided between the thermal head 7 and the head mount 9.
By arranging 0, it is possible to prevent a heat gradient from occurring between the heated part and the non-heated part,
Further, the influence of the members on the head mounting base 9 side (for example, the press-contact lever and the radiation fins 11) can be uniformly transmitted to the thermal head 7 side.

When a buffer substrate 10 having different physical properties and good thermal conductivity is interposed between the thermal head 7 and the head mounting base 9 as in the present embodiment, the head mounting base 9 There is an advantage that the heat applied to the thermal head 7 can be made uniform while suppressing the influence of the members on the side by providing a thermal distance.

More specifically, the thermal gradient of the conventional thermal head 7 was 5% in the vertical temperature difference, but in the present embodiment, it was 1% or less, and the buffer substrate 10 was interposed. As a result, a uniform effect of heat storage was obtained, and a good recording result with uniform print density was obtained.

As described above, according to the present embodiment, it is possible to prevent a change in density and uneven printing in continuous printing, and it is possible to perform quick and high-quality printing.

It should be noted that the present invention is not limited to the above-described embodiment, and can be changed as needed. For example, in the above embodiment, the thermal printer capable of performing both the thermal sublimation recording and the thermal melting recording has been described. However, a thermal printer dedicated to the thermal sublimation recording may be used, or a thermal printer dedicated to the thermal transfer method may be used. Alternatively, it may be a printer that is compatible with both the thermal system and the thermal transfer system.

[0064]

As described above, in the thermal printer according to the present invention, the heat applied to the thermal head can be made uniform by the buffer substrate, and the density change and the printing unevenness in continuous recording can be prevented. Thus, there can be obtained an effect that quick and high-quality recording can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an embodiment of a thermal printer according to the present invention.

FIG. 2 is a schematic side view showing a main part of the thermal printer of FIG. 1;

FIG. 3 is a schematic side view of a carriage of the thermal printer of FIG. 1;

FIG. 4 is a side view showing a head mounting base in the thermal printer of FIG. 1;

FIG. 5 is a bottom view of the head mount in the thermal printer of FIG. 1;

FIG. 6 is a block diagram illustrating a configuration of a control system of the thermal printer of FIG. 1;

[Explanation of symbols]

 Reference Signs List 7 Thermal head 8 Heating part 9 Head mounting base 10 Buffer board 11 Radiation fin

Claims (2)

[Claims] 1. A head mounting base for fixing a thermal head on which a plurality of heating elements are arranged and arranged, and the thermal head is mounted on the platen while reciprocating a carriage mounting the head mounting base along the platen. A thermal printer for performing recording on a recording sheet by selectively applying energy to the heating element by pressing against the recording sheet via a recording sheet, wherein a thermal conductive material is provided between the head mounting table and the thermal head. A thermal printer comprising a good buffer substrate. 2. The thermal printer according to claim 1, wherein the buffer substrate is a Si substrate.