JPH0267167A - Thermal printer - Google Patents

Abstract

PURPOSE:To lower the running cost of an ink ribbon by constituting the title printer so that the ink ribbon is relatively moved in the direction reverse to that during printing with respect to a thermal head after the finish of erasure operation for performing the release erasure of ink. CONSTITUTION:A heating means is driven while a thermal head 17 and an ink ribbon 14 are relatively moved in the first direction in such a state that the ink ribbon 14 is held between the thermal head 17 and printing paper 5 to heat the ink ribbon 14 and the ink already transferred to printing paper 15 by the sticking force of the ink is released and erased. After the finish of erasure operation, the ink ribbon 14 is relatively moved in the second direction reverse to the first direction with respect to the thermal head 17. Thereby, after the finish of erasure operation, the ink ribbon 14 used in erasure operation is unwound and again used in printing or erasure to make it possible to lower the running cost of the ink ribbon 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal printer, and particularly to a thermal printer that performs printing and erasing using the same ink ribbon.

[Prior Art] Conventionally, as a method for erasing erroneous prints in thermal printers, the heating means of the thermal head is driven to melt the ink on the ink ribbon and also the ink of the erroneously printed characters, and the melted viscosity and affinity cause the two to melt. By taking advantage of the fact that the ink is in one piece and peeling off the ink ribbon from the printing paper after the ink has solidified, the ink of the incorrectly printed characters on the printing paper is removed to the ink ribbon side. had been devised. In the conventional erroneous print erasing method described above, erasing is performed using a part of the ink ribbon that has never been used, and the ink ribbon used for the erasing operation is fed a predetermined amount and is never used again. Ta. Therefore, the same amount of ink ribbon had to be consumed during the erasing operation and the printing operation.

[Problems to be Solved by the Invention] However, if the ink ribbon is fed by a predetermined amount during the erasing operation in the same way as during the printing operation, it may be difficult for beginners to type, especially if they have to frequently erase erroneous prints. In this case, the amount of ink ribbon consumed increases and the running cost of the ink ribbon becomes high.

The present invention has been developed in view of the above-mentioned problems, and since the ink ribbon used for the erasing operation has no number of characters, and the ink on the printing paper is stuck on the ink layer of the ink ribbon, it is no longer possible to erase the characters. This method was developed with a focus on the ability to perform multiple printing or erasing operations, and after the erasing operation is completed, the ink ribbon used for the erasing operation is sent in the opposite direction to the normal feeding direction, and printing or erasing is performed again. The purpose of this is to reduce the running cost of the ink ribbon.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the thermal printer of the present invention connects the thermal head and the ink ribbon with the ink ribbon being held between the thermal head and the printing paper. printing control means for heating the ink ribbon by driving a heating means while relatively moving in a first direction to perform printing based on the thermal transferability of the ink; and the ink ribbon is sandwiched between a thermal head and a printing paper. While moving the thermal head and the ink ribbon relative to each other in a first direction, the heating means is driven to heat the ink ribbon, and the ink that has already been transferred onto the printing paper is peeled off by the adhesive force of the ink. The ink ribbon includes an erasure control means for erasing, and a ribbon reverse movement means for moving the ink ribbon relative to the thermal head in a second direction opposite to the first direction after the erasure operation by the erasure control means is completed. .

[Function] In the thermal printer of the present invention having the above configuration, after the erasing operation by the erasing control means is completed, the ribbon reverse running means is driven to move the ink ribbon relative to the thermal head in the opposite direction to that during printing. let

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a flat platen 2 is fixed laterally between a pair of frames (not shown) disposed on both sides of a thermal printer main body 1. As shown in FIG. This platen 2 supports a printing paper 5 inserted into a paper insertion path as a paper feed roller 4 rotates and is driven and connected to a paper feed motor 3. Further, a carriage guide 6 and a guide shaft 7 parallel to the platen 2 are respectively fixed to the frame. A carriage 8 is supported by the carriage guide 6 and the guide shaft 7 so as to be able to reciprocate along the longitudinal direction of the platen 2 . A drive wire 11 connected to a carriage drive motor 9 via a drive pulley 10 is attached to the carriage 8, so that the carriage 8 is reciprocated as the carriage drive motor 9 rotates forward and backward. It is configured as follows.

A ribbon cassette 12 is removably placed on the carriage 8. A supply spool 13a and a take-up spool 13b are rotatably supported within the ribbon cassette 12, and an ink ribbon 14 is wound on both spools. The ink ribbon 14 has a film-like support made of polyester or the like coated with heat-melting ink. Furthermore, this heat-melting ink melts at a predetermined printing temperature and has the property of increasing adhesive strength.

Next, the internal structure of the carriage 8 will be explained using FIGS. 2 and 3. In addition, in FIG. 2, only the outer frame of the carriage 8 is broken at the lower part in order to make it easier to understand the internal structure of the carriage 8.

At the rear of the carriage 8, a support arm 15 is rotatably supported by a support shaft 16 at a position to the right of its middle portion, and a thermal head 17 is supported and fixed to the left end of the support arm 15. .

As shown in FIG. 2, this thermal head 17 has a first heating element group 17a1 at its left end and a second heating element group 17b at its right end, and when printing, the left first heating element group 17a1 is erased. When doing so, the second heating element group 17b on the right is used. Each heating element group has a large number of heating elements,
Printing is performed on the printing paper 5 in the form of dots by selectively causing the required heating elements to generate heat based on the printing data. A coil spring 18 is stretched between the support arm 15 and the carriage 8, and the coil spring 18 urges the support arm 15 clockwise in FIG. 2 around the support shaft 16. Thereby support arm 1
The thermal head 17 at the tip of 5 is pressed against the platen 2 with a constant pressure. Further, in FIG. 2, a fixing plate 21 is disposed near the right end of the support arm 15,
A cam shaft 22 is fixed to this fixed plate 21 in parallel with the platen 2. On this camshaft 22 is an idle gear 23.
An elliptical cam 24 integrally formed with is rotatably supported. Further, the idle gear 23 is connected to the carriage 8.
It meshes with a pinion 26 fixed on the motor shaft of a drive motor 25 fixed therein. With the above-described structure, the elliptical cam 24 rotates with the rotation of the drive motor 25 and engages with the right front surface of the support arm 15, so that the distal end of the support arm 15 is rotated as shown by the dashed line in FIG. The release position is separated from the platen 2 against the action of the coil spring 18, and the printing position is when the tip of the support arm 15 is in contact with the platen 2 due to the action of the coil spring 18, as shown by the solid line in FIG. 2 during printing. Move between positions.

Further, on the left front surface of the support arm 15, an operating arm 27a is formed to protrude forward for separating a planetary gear 41, which will be described later, from a take-up spool gear 28a during non-printing. The tip of this operating arm 27a is connected to a planetary gear 41.
The surface that engages with the support shaft is inclined, and when engaged, the support shaft is configured to move along that surface due to the cam action of both.

Further, a planetary gear 4 is provided on the central front surface of the support arm 15.
An actuating arm 27b is formed to protrude forward for separating 1 from the supply spool gear 29a during non-printing.

The distal end of the operating arm 27b has a sloped surface that engages with the support shaft of the planetary gear 41, and when engaged, the support shaft is configured to move along that surface due to the cam action of both.

Further, the lower end of a take-up spool shaft 28 extending upward is rotatably supported on the carriage 8, and a supply spool shaft 29 is rotatably supported on the right side thereof. and,
A take-up spool gear 28a and a supply spool gear 29a are supported at intermediate portions of both the spool shafts 28 and 29, respectively, so as to be rotatable together with the shafts. Further, a shaft 31 is mounted on the carriage 8 in front between the two spool shafts 28 and 29.
is fixed, and a shaft cover 32 made of resin and having a disc-shaped upper part is loosely fitted onto the shaft 31.

As shown in FIG. 3, a driven gear 33 is supported at an intermediate portion of the shaft cover 32 so as to be slidable and rotatable together with the shaft cover 32. The driven gear 33 is
A pinion 3 rotatably supported on the carriage 8 in engagement with a rack 34 disposed parallel to the platen 2.
5 is always connected. Further, a slip gear 36 is supported on the shaft cover 32 portion above the driven gear 33 so as to be slidable in the axial direction and rotatable. Further, a pulley 37 is loosely fitted into the lower part of the shaft cover 32, and a compression coil spring 38 is wound around the portion of the shaft cover 32 between the pulley 37 and the driven gear 33. , the driven gear 33 and the slip gear 36 move upward due to the spring force, and the spring holder pushes the pulley 3 upward.
7 is biased downward. Thereby, the shaft cover 32. Driven gear 33. The slip gear 36, the spring receiver, and the pulley 37 are constructed so that they can always rotate together.

Further, felt 39 is attached to both sides of the slip gear 36, and the slip gear 36 is configured to slip between the shaft cover 32 and the driven gear 33 when a load exceeding a predetermined value is applied to the slip gear 36. .

Note that the predetermined value described here is a size that does not cause plastic deformation of the ribbon portion to be rewound or wound up by being pulled between both spools 13a and 13b. A movable arm 40 is rotatably supported at one end of the portion of the shaft 31 that protrudes from the upper part of the shaft cover 32. A planetary gear 41 is rotatably supported at the lower end of the other end of the movable arm 40, and the planetary gear 41 is always meshed with the slip gear 36. Further, the planetary gear 41 is rotated by the supply spool gear 29a as the movable arm 40 rotates clockwise or counterclockwise in FIG. 2 in accordance with the moving direction of the carriage 8.
1 or the take-up spool gear 28a.

Next, the operation of the thermal printer configured as above will be briefly explained.

During printing or erasing, the drive motor 25 rotates by a predetermined amount, rotates the idle gear 23, and the cam! ll12
The engagement between the elliptical cam 24 on 2 and the support arm 15 is released. As a result, the support arm 15 at the release position is biased clockwise by the restoring force of the coil spring 18 as shown in FIG. 2, and the thermal head 17 is moved to the printing position where it is pressed against the printing paper 5 on the platen 2. . The carriage 8 moves in the print line direction as the carriage drive motor 9 rotates.

Along with this movement of the carriage 8, when printing, required heating elements in the first heating element group 17a at the left end of the thermal head 17 are energized based on print data. At this time, the ink ribbon 14 is heated, and when the temperature reaches a predetermined printing temperature, the heat-melting ink coated on the ink ribbon 14 becomes molten and has increased adhesive strength, and is transferred onto the printing paper 5 to perform printing. Further, when erasing, electricity is applied to required heating elements in the second heating element group 17b at the right end of the thermal head 17 based on print data. As a result, the ink on the ink ribbon 14 is melted, and the ink of the erroneously printed characters is also melted, and by utilizing the fact that the two melted materials become one due to their melt viscosity and affinity, the integrated ink solidifies. By peeling the ink ribbon 14 from the printing paper 5, the ink of the erroneously printed characters on the printing paper 5 is removed to the ink ribbon 14 side and erased. Furthermore, by the movement of the thermal pad 17, the print ribbon 14 wound around the supply spool 13a in the ribbon cassette 12 is sequentially pulled out.

Further, as the carriage 8 moves, the pinion 35 that engages with the rack 34 rotates clockwise in FIG. Rotate the arm 40 counterclockwise. Thereby, the planetary gear 41 meshes with the take-up spool gear 28a, and the rotational force is applied to the take-up spool shaft 28a.
It acts to rotate the take-up spool 13b counterclockwise through. By this rotation, the print ribbon 14 is sequentially wound onto the take-up spool 13b. After that, when a load of more than a predetermined value is applied to the take-up spool 13b due to the tension generated in the ribbon portion between the take-up spool 13b and the thermal head 17, the slip gear 35 and the shaft cover 3
2 and the driven gear 33, and the rotational force of the planetary gear 40 decreases, so that the take-up spool 13b
rotation is suppressed.

Next, when the thermal pad 17 is released and moved to the character position to be erased, the drive motor 25 rotates by a predetermined amount, rotates the idle gear 23, and engages the elliptical cam 24 and the support arm 15. Accordingly, support arm 1
5 counterclockwise against the spring force of the coil spring 18 as shown by the dashed line in FIG.
evacuate. Further, by rotating the support arm 15, the tip of the actuating arm 27a or the actuating arm 27b engages with the support shaft of the planetary gear 41, and by rotating the movable arm 40 clockwise or counterclockwise, the planetary gear 41 and the take-up spool gear 28a or the supply spool gear 29a. As a result, the thermal head 17
When the ink ribbon 14 is released, even if the carriage 8 moves, the ink ribbon 14 can be moved to the desired character position without being wound up or rewound.

Next, when rewinding the ink ribbon 14, that is, when the carriage 8 moves to the left while the thermal head 17 is in pressure contact, after the thermal head 17 is in pressure contact, the carriage 8 is rotated by the carriage drive motor 9. The first
Move to the left as shown in the diagram. As the carriage 8 moves, the pinion 35 that engages with the rack 34 rotates counterclockwise in FIG. Rotate the arm 40 clockwise. Thereby, the planetary gear 41 meshes with the supply spool gear 29a, and the rotational force acts via the supply spool shaft 29 to rotate the supply spool 29a clockwise. As a result of this rotation, the print ribbon portions pulled out from the supply spool 13a by the thermal head 17 during printing are sequentially rewound onto the supply spool 13a.

Next, the electrical configuration of the electronic typewriter constructed as described above will be explained based on FIG. 4.

The central processing unit (hereinafter referred to as CPU) 50 has a read-only memory (hereinafter referred to as CPU) having a program memory 61 that stores control programs and a print pattern memory 62 that stores character patterns to be printed out.
Random access memory (ROM) 60 and various memories that temporarily store calculation results of the CPU 50, etc.
A memory (hereinafter referred to as RAM) 70 is connected.

Then, the CPU 50 performs printing and erasing operations based on the control program stored in the program memory 61. Further, the RAM 70 is provided with a head flag 72 that indicates that the thermal head 17 is at the print position, an erase flag 73 that indicates that a correction operation has been performed, and a print buffer 71 that sequentially stores data input manually. , the print buffer 71 stores a number of data corresponding to the number of characters printed in one print line on the print paper 5.

In addition, the CPU 50 has character/symbol keys on the keyboard 80,
As the first erase key, second erase key, etc. are connected,
A thermal printer 90 having the mechanism shown in FIGS. 1 to 3 is connected, and prints or erases based on commands from the CPU 50.

The CPU 50 sequentially stores character/symbol data input from the character/symbol keys of the keyboard 80 and erase data input from the erase key in a predetermined storage area of the print buffer 71 in correspondence with the print position, and reads them out using the buffer pointer. By specifying the position, data in the print buffer 71 is sequentially read out, and printing and erasing operations are performed while moving the head position of the thermal head 17 back and forth.

If the data pointed to by the buffer pointer is erasing data, the CPU 50 reads character/symbol data corresponding to the printed characters on the print paper 5 to be erased by the erasing data from the print buffer 71 and causes the erasing operation to be performed. At this time, the CPU 50 drives the carriage drive motor 9 to perform the erasing operation as the head position moves forward while keeping the thermal pad 17 in the pressure contact position.

Next, the operation of the thermal printer configured as described above will be explained based on the flowchart of FIG. 5 and FIG. 6. Note that FIG. 6 shows the thermal head 17 and the ink ribbon 1.
4 and a printing paper 5 conceptually.

First, in step Sl (hereinafter simply referred to as Sl; the same applies to other steps), initial settings such as turning off the head flag 72 and erasure flag 73 are performed.

Next, at 82, the key is put on standby. If the key is pressed manually, the process moves to 83, and if it is determined that the print key has been pressed, the process moves to S4; otherwise, the process moves to S9. In S4, it is determined whether the thermal head 17 is in pressure contact or released. That is, it is determined whether the head flag 72 is ON or OFF, and if it is ON, the process skips to S7. If it is OFF again, S5
The process moves to press the thermal head 17, turns on the head flag 72 in S6, and moves to S7. The state at this time is shown in FIG. 6(a). In S7, as shown in FIG. 6(b), while moving the thermal head 17 to the right by one character, the first heating element group 27a selectively generates heat to print characters, symbols, etc. That is, by the movement of the thermal pad 17, the print ribbon 14 wound around the supply spool 13a in the ribbon cassette 12 is sequentially pulled out, reads character/symbol data from the print buffer 71, and prints a dot pattern corresponding to the data. Printing is performed while reading from the pattern memory 62.

Next, in S8, the erasing flag 73 indicating that the erasing operation has been performed is turned off, and the process returns to S2, where the manual key operation is performed. If it is determined in S3 that the pressed key is not a print key, the process moves to S9. When it is determined that the key input in S9 is the first erase key that can erase multiple characters in succession, the process proceeds to S10.
Move to. In S10, the head flag 72 is used to check whether the thermal/rad 1 is in pressure contact, and the head flag 7 is checked.
If 2 is OFF, skip to 813, if ON, S
The program advances to step 11, releases the thermal head 17, turns off the head flag 72, and advances to step S13. 6th in 313
As shown in Figure (c), move the thermal head 17 to align the second heating element group 17b with the left end of the character to be erased. Next, in step 314, the thermal head 17 is brought into pressure contact.

The state at this time is shown in FIG. 6(d). In S15, while moving the thermal head 17 to the right, the second heating element 'r
'317b is selectively heated and erased.

At this time, the thermal head 17 presses and moves to the right, so that the ink ribbon 14 wound around the supply spool 13a in the ribbon cassette 12 is sequentially pulled out, and the characters printed on the printing paper 5 to be erased are attached to the ink ribbon 14. The corresponding character/symbol data is read from the print buffer 71, and the dot pattern corresponding to the data is stored in the print pattern memory 6.
Erasing is performed while reading from 2. The state when this erasing operation is completed is shown in FIG. 6(e). This operation causes the ink on the printing paper 5 to be peeled off from the printing paper 5 and removed to the ink layer side of the ink ribbon 14, so that the ink ribbon 14 can be used again for printing or erasing. Next, in S16, the thermal radar 17 is moved to the left as shown in FIG. 6(f) to align the first heating element group 17a with the left end of the erased character. When the thermal head 17 is pressed and moved to the left, the ink ribbon 14 wound around the take-up spool 13b in the ribbon cassette 12 is sequentially pulled out, and the ink ribbon 14 used for erasing is rewound.

Therefore, the area of the ink ribbon 14 once used for erasing can be used again for printing. In S17, the erase flag 73
Turn on and return to S2 key power.

Next, the flow when the second erase key is pressed to erase the same location twice in order to improve the quality of erasure will be explained. If it is determined that the pressed key is the second erase key in S18, the process moves to S19; otherwise, the process moves to S24, where other processing is performed, and the process returns to S2, where the key is manually pressed.

In S19, it is determined whether the erasure flag 72 is ON or OFF, and
If it is OFF, the process moves to S10, performs the same erasing operation as when the first erasing key was pressed, and returns to S2. This completes the first erase operation. If the second erase key is pressed again here, S3. S9. S18. Proceed to S19.

The erase flag is checked in S19, and since it is ON this time, the process moves to 320. In S20, check whether the thermal head 17 is in pressure contact with the head flag 72. If the head flag is ON, skip to 523. If it is OFF, proceed to S21, press the thermal head 17, and turn the head flag 72 ON.
and move to 323. In S23, the thermal head 17 is moved to the left as shown in FIG. 6(g) to align the second heating element group 17b with the left end of the erased character. By moving the thermal head 17 to the left in a pressed state, the ink ribbon 14 is rewound further, and the area used for erasing can be used again for erasing.

Thereafter, the process moves to 316, where the second erasing is performed, and in S17, the erasing flag 73 is turned on, and the process returns to S2.

The thermal printer of the present invention is not limited to the above embodiments, but can be implemented in various forms without departing from the gist of the present invention. For example, in the present invention,
Printing or erasing was performed only when the carriage moved to the right, but
When the carriage moves to the left, the design is changed so that printing or erasing can be performed from the opposite direction by using the second heating element group on the right when printing and using the first heating element group on the left when erasing. is easy for those skilled in the art.

[Effects of the Invention] As is clear from the detailed description above, the thermal printer of the present invention can rewind the ink ribbon used for the erasing operation after the erasing operation is completed and use it again for printing or erasing, thereby removing the ink. It becomes possible to reduce the running cost of the ribbon.

[Brief explanation of the drawing]

1 to 6 show embodiments embodying the present invention. FIG. 1 is a perspective view of the road body of the printing mechanism according to the present invention, and FIG. 2 is a plan view of the internal structure of the carriage. , FIG. 3 is a sectional view of the internal structure of the carriage, and a diagram conceptually showing the positional relationship between the round head, the ink ribbon, and the printing paper. In the figure, 14 is an ink ribbon, 17 is a thermal head, 1
7a is a first heating element group, and 17b is a second heating element group.

Claims (1)

[Claims] 1. A thermal head having heating means and relatively movable along printing lines of printing paper supported by a platen,
In a thermal printer that is capable of printing and erasing by using an ink ribbon that has ink that produces thermal transferability or adhesiveness depending on temperature conditions, the ink ribbon is held between a thermal head and printing paper. printing control means for heating the ink ribbon by driving the heating means while relatively moving the thermal head and the ink ribbon in a first direction to perform printing based on the thermal transferability; While the thermal head and the ink ribbon are moved relative to each other in a first direction while being held between the thermal head and the printing paper, the heating means is driven to heat the ink ribbon, and the adhesive force causes the ink ribbon to be heated onto the printing paper. an erasure control means for peeling off and erasing ink that has already been transferred; and a ribbon for moving the ink ribbon relative to the thermal head in a second direction opposite to the first direction after the erasure operation by the erasure control means is completed. A thermal printer comprising a reverse running means.