JPH11301003A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To radiate accumulated heat on a head substrate of a thermal head in a short time and to effectively obtain a good recording result by a constitution wherein a heat-radiating sheet made of a material having a high thermal conductivity which is greater than that of a material forming the head substrate is stuck on an exposed portion of the surface of the head substrate. SOLUTION: A heat-radiating sheet 11 is formed in a sheet type from a material having a high thermal conductivity, e.g. Al, Cu, Si, or the like so that a thermal efficiency of a heating portion 8 is improved. The thermal conductivities are 238 W/m deg.C by Al, 385 W/m deg.C by Cu and 150 W/m deg.C by Si. In this embodiment, the heat radiating sheet 11 is formed from Al in consideration of easy processability and low cost. A silicone series of adhesive having a good thermal conductivity is used for adhering of a head substrate 7a and a flexible print circuit 10 with the heat-radiating sheet 11. It is preferable to use the adhesive having the thermal conductivity of 1.7 W/m deg.C.

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, the surface temperature of the head substrate, the environmental temperature of the thermal head, and the like are detected by a thermistor.
Until the heat storage is released and the temperature becomes equal to or lower than a certain temperature, the recording operation is temporarily stopped, and control is performed to wait.

Conventionally, in order to release the heat stored in the head substrate as much as possible, a means such as disposing a heat sink behind the thermal head mounting base on which the substrate of the thermal head is mounted is employed. Was.

[0010]

However, a considerable amount of time is required for the heat radiation, so that it takes about 20 minutes to record A4 size paper, and the recording efficiency is poor.

Further, as described above, the heating element selectively generates heat based on the recording information. In other words, the thermal head has a portion that generates heat due to the recording information and a portion that does not generate heat at all. Will do. 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.

[0012] The present invention has been made in view of the above points, and by diffusing a partial heat storage of a head substrate in a short time and releasing the heat storage of the head substrate in a short time,
It is an object of the present invention to provide a thermal printer capable of efficiently obtaining good recording results.

[0013]

According to a first aspect of the present invention, there is provided a thermal printer in which an exposed portion of a surface of a head substrate of a thermal printer has a higher thermal conductivity than a material constituting the head substrate. A heat radiation sheet made of a material exhibiting a high efficiency.

According to the present invention, the partial heat storage of the heating element is diffused in the entire heat radiation sheet in a short time, and the heat storage of the head substrate itself is released from the heat radiation sheet in a short time. it can.

According to a second aspect of the present invention, there is provided a thermal printer, wherein a part of a heat radiation sheet made of a material having a higher thermal conductivity than a material forming the head substrate is provided on an exposed portion of a surface of the head substrate of the thermal printer. 4. The thermal printer according to claim 3, wherein at least a part of the remaining portion of the heat dissipation sheet is attached to a peripheral member of the thermal head other than the head substrate. The printer is the thermal printer according to claim 2, wherein the peripheral member of the thermal head other than the head substrate is an FPC bonded to a surface of the head substrate.

According to the invention described in these claims,
The head substrate can be radiated in a short time by dissipating heat from the heat radiating sheet and conducting heat storage of the heating element to other peripheral members of the thermal head via the heat radiating sheet.

According to a fourth aspect of the present invention, there is provided the thermal printer according to any one of the first to third aspects, wherein the heat dissipation sheet has an end edge aligned with the heating element. And bonded to an exposed portion of the surface of the head substrate so that the shape is symmetrical by an imaginary line which divides the entire heat generating portion into two parts at right angles to a direction in which the heat generating elements are arranged and which is orthogonal to the direction in which the heat generating elements are arranged. It is characterized by having been done.

According to the thermal printer of the present invention, the heat radiation of the head substrate using the heat radiation sheet can be more effectively performed.

[0019]

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 is driven by a carriage motor (not shown) to drive a suitable driving belt 6 wound around a pair of pulleys (not shown) so as to reciprocate 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 is brought into and out of contact with the platen 2 by a well-known head moving mechanism (both not shown) which is opposed to the platen 2 and is 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.

As shown in FIG. 4, the thermal head 7 is provided at one end of a substantially L-shaped head pressure contact lever (not shown) attached to the carriage 4 so as to swing about a support shaft. The head substrate 7 is adhered and fixed to the mounted head mounting base 9, and a plurality of heating elements are arranged and arranged on the upstream side in the moving direction of the carriage 4 on the head substrate 7 a during the recording operation. A heated heat generating portion 8 is formed. A flexible print circuit (hereinafter, referred to as an FPC) that can supply current to a heating element of the heating unit 8 is provided at a downstream end portion of the carriage 4 on the thermal head substrate 7a during a printing operation in a moving direction. 10 is adhered and fixed by soldering, and the heat generating element of the heat generating section 8 is selectively heated based on desired recording information input by a suitable input device (not shown) such as a keyboard. Has become.

In this embodiment, as shown in FIGS. 4 and 5, one heat dissipation sheet 11 having a rectangular shape has one end side formed on the surface of the head substrate 7a. In the vicinity of 8, the heating elements are positioned in the alignment direction, and the other end is positioned on the FPC 10 so as to be bonded to the head substrate 7a and the FPC 10.

The heat radiation sheet 11 is provided on the head substrate 7.
The exposed part of the surface of the head a is covered as widely as possible, and its shape is made symmetrical by an imaginary line that divides the whole of the heating part 8 into two orthogonally to the direction in which the heating elements formed on the head substrate 7a are aligned. Adhered to. With such a structure, the heat stored in the heat generating portion 8 can be efficiently released with good balance.

The heat radiating sheet 11 is made of a material having a high thermal conductivity, for example, Al, Cu, Si or the like, in order to improve the heat radiating efficiency of the heat generating portion 8. Their thermal conductivity is 238 W / m ° C. for Al,
Cu is 385 W / m ° C and Si is 150 W / m ° C.
In the present embodiment, the heat dissipation sheet 11 is formed of Al in consideration of ease of processing and low cost.

The head substrate 7a and the FPC 1
For bonding the heat-dissipating sheet 11 to the heat-dissipating sheet 11, a silicone-based adhesive having good heat conductivity is used. For example, an adhesive KE3493 made by Shin-Etsu Silicone can be used. The adhesive has a thermal conductivity of about 1.7 W / m ° C.

Further, similarly to the heat radiation sheet 11, the head mounting base 9 is made of a material having a high thermal conductivity, such as Al die cast, pure Al and Cu, in order to improve the heat radiation efficiency of the heat generating portion 8. (Copper) or the like. The thermal conductivity of Al die-cast is 96 W / m ° C.
It is. In the present embodiment, the head mounting table 9 is formed by Al die casting in consideration of easiness of processing and low cost.
Is formed. Further, on the back of the surface of the head mounting base 9 to which the thermal head 7 is fixed, a radiation fin (not shown) is formed at a position directly below the heat generating portion 8, and the heat storage of the heat generating portion 8 is performed. Is radiated from the back side of the thermal head 7. The thermal head 7 is provided with a thermistor (not shown). By detecting the temperature of the thermal head 7, it is possible to control the driving and stopping of the recording operation.

In the thermal head 7, the control unit 29 described later makes it possible to select one of a strong press contact and a weak press 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 carriage 4 is configured such that a plate-like upper carriage 4b, which is substantially parallel, 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.

A rotary crank mechanism 15 is provided on the lower carriage 4a, and the upper carriage 4b is moved in parallel by the rotary crank mechanism 15. 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 a lower surface of the canopy 23 facing the carriage 4 in parallel. In the embodiment, a ribbon cassette 5a in which an ink ribbon (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 heat-sublimable ink ribbon 21b.

Each of the ribbon cassettes 5a, 5 according to 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.

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 identifying 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, a reflection sticker 28A having four non-reflection portions 28a is arranged as an identification mark 27 on the ribbon cassette 5a shown on the left side in FIG. 1, 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 or a winding of the ink ribbon for bringing the thermal head 7 into and out of contact with the platen 2. 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 configured to output a signal 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 control of the rotation speed of the carriage motor and the ribbon take-up motor is performed 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.

Further, a recording speed detecting means (not shown) for detecting the recording speed by the carriage 4 is provided, and the result of the detection is inputted to the control section 29, and the control section is controlled based on the result. 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 the type of the ribbon cassette 5 to be used, the recording mode, the recording medium and the 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 according to the present embodiment and selecting the recording mode so as to meet the purpose of recording can be performed automatically or by operating the mode changeover switch 30 by the operator. 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 an instruction 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 this 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 set to a constant value. 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 shown. 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.

Further, since the ribbon cassette 5 in this 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 set to the optical sensor. 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 / close 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 containing therein the ink ribbon 21 corresponding to the selected recording mode.
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 first recording mode, a command from the first recording mode control unit 32 of the control unit 29 causes
The pressing force of the thermal head 7 against the platen 2 in the head down state 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 5 to 50 cm / sec, and the heat generation of the thermal head 7 The energizing time per dot of the section 8 is 0.1 msec.
When the energization time has elapsed, the temperature of the heat generating portion 8 becomes 6
Control is performed so that the temperature rises to 00 ° C. by energizing one pulse. 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 reducing the pressing force of the thermal head 7 against the platen 2 in the second recording mode as compared with that in the first recording mode, the 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.

Further, when such recording, especially thermal sublimation transfer recording, is performed, the energy added to the heat generating portion 8 of the thermal head 7 is large, so that the heat storage is also large. Is the thermal head 7
Is fixed to a head mounting base 9 made of Al die cast having high thermal conductivity, and a plurality of radiating fins formed on the head mounting base 9 immediately below the heat generating portion 8 to store heat on the back surface of the thermal head 7. Dissipates heat from the side,
The heat storage sheet 11 made of Al whose one end is bonded to an exposed portion of the surface of the head substrate 7a releases its heat storage from the surface of the heat dissipation sheet 11 by contact with air or a recording medium, or Via 11
By conducting the heat storage of the head substrate 7 a to the FPC 10, the heat storage is also actively dissipated efficiently from the surface side of the thermal head 7.

In particular, the heat radiating sheet 11 is projected not only on the head substrate 7a but also on the FPC 10,
The heat dissipation efficiency can be further improved by forming a large area.

As described above, by actively radiating heat from both the front and back surfaces of the thermal head 7, the time required for the heat radiation can be significantly reduced as compared with the conventional case. More specifically, when the temperature of the thermal head 7 rises due to heat storage, a conventional thermal printer requires a recording time of about 20 minutes for A4 size paper. , That time is half of the conventional 10
Minutes.

Further, in the present embodiment, the width of the heat radiating sheet 11 is formed to be equal to or larger than the size of the heat generating elements in the alignment direction, so that the heat generating elements of the heat generating portion 8 and the heat generating elements which do not generate heat are formed. The heat gradient generated between the heat generating element and the heat generating element can be made uniform in a short time, and the heat storage of the heating element can be diffused. As a result, when continuous printing is performed, a change in density between pages can be reduced to a level that cannot be visually recognized, and a good printing result with uniform print density can be obtained. In the present embodiment, the diffused heat storage of the thermal head 7 is radiated as needed through contact with the air or the recording medium via the heat radiation sheet 11 or is transmitted to the FPC 10 side, thereby transmitting the thermal head 7. It goes without saying that heat is dissipated. Therefore, the number of times the control for temporarily stopping the recording operation is performed by detecting the temperature of the thermal head 7 by the thermistor (not shown) can be reduced.

As described above, according to the present embodiment, the heat storage of the thermal head can be efficiently diffused and released, so that the density change and the printing unevenness in the continuous recording can be prevented, and the thermal storage can be performed quickly and efficiently. It is possible to record quality.

The member capable of transmitting the heat stored in the thermal head 7 from the head substrate 7a via the heat radiation sheet 11 is not limited to the above-described FPC 10. For example, in the case of the heat radiating sheet 11 formed in a substantially rectangular shape like the heat radiating sheet 11 of the above-described embodiment, one end of the heat radiating sheet 11 is attached to the exposed surface of the head substrate 7a, A part is attached to a member located separately from the head substrate 7a, and the heat dissipation sheet 11 is straddled between both members. Further, it is needless to say that the member capable of conducting the heat storage of the thermal head 7 from the head substrate 7a via the heat radiation sheet 11 is not limited to one member, but may be two or more members.

Further, as shown in FIGS. 7 and 8, the heat radiating sheet 11 can be provided only on the exposed portion of the surface of the head substrate 7a.

As described above, even when the heat radiation sheet 11 is adhered only on the surface of the head substrate 7a, the heat radiation sheet 11 is adhered to the vicinity of the heat generating portion 8 so as to cover the exposed portion of the surface of the head substrate 7a. The heat dissipation sheet 11 allows the heat storage of the heat-generating elements to be diffused in a short period of time, so that the heat gradient generated between the heat-generating element portion of the heat-generating portion 8 and the heat-generating element portion that did not generate heat can be made uniform. In this case, the change in density between pages can be reduced to a level that cannot be visually recognized, and there is no change in the effect that a good recording result with uniform print density can be obtained.

In the present embodiment, the diffused heat storage of the head 7 is conducted to a printing medium, air, etc., which come into contact during a recording operation, through a heat radiating sheet 11 made of a material having a high thermal conductivity. Thus, the heat radiation from the front side of the thermal head 7 is actively performed. As a result, the time required for the heat radiation can be significantly reduced.

The present invention is not limited to the above-described embodiment, but can be modified 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.

[0074]

As described above, the thermal printer according to the present invention uses the heat radiating sheet attached to the head substrate.
The thermal storage of the thermal head is positively released, and an effect is obtained in that rapid and high-quality recording can be performed by preventing density changes and printing unevenness in continuous recording.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a thermal printer according to a first embodiment of 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 front view showing a thermal head part in the thermal printer of FIG. 1;

FIG. 5 is a plan view showing a thermal head part 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;

FIG. 7 is a front view showing a thermal head portion in a thermal printer according to a second embodiment of the present invention.

FIG. 8 is a plan view showing a thermal head part in the thermal printer of FIG. 7;

[Explanation of symbols]

 7 Thermal head 8 Heating part 9 Head mounting 10 FPC 11 Heat dissipation sheet

Claims (4)

[Claims] 1. A thermal head having a heating portion formed of a plurality of heating elements arranged in a row on a surface of a head substrate is mounted on a carriage, and the thermal head is moved to the platen while reciprocating the carriage along the platen. A thermal printer that presses against a recording paper and selectively applies energy to the heating element to perform recording on the recording paper, wherein a head substrate is formed on an exposed portion of a surface of the head substrate. A thermal printer comprising a heat radiating sheet made of a material having a higher thermal conductivity than the material. 2. A thermal head having a heating portion formed of a plurality of heating elements arranged in a row on a surface of a head substrate is mounted on a carriage, and the thermal head is mounted on the platen while reciprocating the carriage along the platen. A thermal printer that presses against the recording medium via a recording paper to selectively apply energy to the heating element to perform recording on the recording paper, wherein the head substrate is formed on an exposed portion of the surface of the head substrate. A part of a heat radiation sheet made of a material having a higher thermal conductivity than the material to be bonded is adhered, and at least a part of the remaining part of the heat radiation sheet is adhered to other thermal head peripheral members other than the head substrate. Thermal printer characterized by wearing. 3. A thermal head peripheral member other than the head substrate includes an FP bonded to a surface of the head substrate.
3. The thermal printer according to claim 2, wherein the thermal printer is C. 4. The radiating sheet has an edge positioned substantially parallel to the direction in which the heating elements are arranged, and is formed by a virtual line that is orthogonal to the direction in which the heating elements are arranged and bisects the entire heating section. 4. The thermal printer according to claim 1, wherein the thermal printer is bonded to an exposed portion of a surface of the head substrate so as to have a symmetrical shape.