JPS63286366A - End-face type thermal printer - Google Patents

Abstract

PURPOSE:To obtain the best-suited printing quality without depending on the difference of distance (end-face distance) from the heat-generating part of a printing head to an end face at the rear end in a printing direction by providing an energization energy setting means to be set in accordance with distance between the heat-generating part and the end face. CONSTITUTION:Heat-melting ink ribbon M1 is pressed against printing paper by a heat-generating part provided near an end face at the rear end of a printing head M2 in a printing direction. Then the heat-generating part of the printing head M2 is energized by an energization means M3 based on printing information to generate heat which thermally melts the ink ribbon M1. At the same time, the printing head M2 is moved in a printing direction by a printing head moving means M4 to permit printing paper to be printed. However, the energization energy amount to be supplied to the heat-generating part of the printing head by the energization means M3 is a value to be set in conformity with the endface distance of the printing head 2 by an energization energy setting means M5. Consequently, the energization means M3 works to supply to the heat-generating part an energization energy amount determined in accordance with the end-face distance of the printing head M2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an end-face type thermal printer in which a heat-generating portion is provided near the end face of a print head on the rear end side in the printing direction.

[Prior Art] Conventionally, thermal printers equipped with a thermal head have been used. This thermal printer has features such as beautiful printed characters and quiet printing sound.

On the other hand, in recent years, the viscosity of the ink layer of the ink ribbon that is melted by the heat generating part of the thermal head has been increased, and even if an erroneous print is made, the same ink ribbon can be used to peel off and erase the characters on the print paper (lift-off, correction). ) There are also thermal printers that can do this. In a thermal printer capable of performing this lift-off correction, a so-called end-face type thermal head is used, in which a heat-generating portion is located near an end face away from the end face on the rear end side in the printing direction of the print head in the micro-amount printing direction side. There is. As a result, the ink ribbon is peeled off from the paper before the temperature of the ink ribbon that has been heat-fused by the heat-generating section is lowered, and the heat-melted ink ribbon is transferred onto the paper.

[Problems to be Solved by the Invention] However, edge-type thermal printers using edge-type heads have the following problems.

In other words, when printing using an ink ribbon with a highly viscous ink layer, in order to obtain high-quality and suitable prints, the heated ink ribbon must be placed on the paper at a constant high temperature before the temperature drops. It needs to be removed from. Here, the conditions for peeling off the ink ribbon at a constant temperature are as follows:
Assuming that the amount of heat generated by the heat generating part is constant, the transition speed of the thermal head (i.e. printing speed) and the distance 11t from the heat generating part of the head to the end face on the rear end side in the printing direction (hereinafter referred to as end face distance)
It is desirable that the time (timing) from when the ink ribbon is heated until it is peeled off is made constant by keeping each of them constant. However, since the distance between the end faces is very small, considerable variation occurs in production. For this reason, the time it takes to peel off the ink ribbon from the paper differs depending on each head, and the temperature at which the ink ribbon is peeled off varies accordingly, leading to the problem that the print quality of characters printed on the paper differs for each head. there were.

The edge-type thermal printer of the present invention has been made to solve the above-mentioned problems, and is constructed as follows.

[Means for solving the problems] The edge-type thermal printer of the present invention, as shown in FIG. There is a heat generating part made of an electrical resistance element near the end face away from the end face in the micro-amount printing direction, and the heat generating part presses the ink ribbon against the printing paper, and the heat generated by the heat generating part causes the ink to be heated. The print head (M2) prints by thermally melting the ribbon, and the print head (M2) prints on the basis of print information.
Along with printing by the energizing means (M3) that energizes the heat generating part of the print head (M2) and the print head (M2), the print head (M
2) in an end-face type thermal printer equipped with a print head moving means (M4) that relatively moves the head in the printing direction, the amount of energization energy supplied to the heat generating part by the power supply means (M3) is set to The present invention is characterized in that it includes energization energy setting means (M5) that sets the energization energy according to the distance between the energization energy and the end face.

[Function] The edge-type thermal printer of the present invention having the above-mentioned configuration has the following features: A heat-fusible ink ribbon (Ml) is applied to printing paper by a heat generating section provided near the end surface on the rear end side of the print head (M2) in the printing direction. The energizing means (M3) energizes the heat-generating part of the print head (M2) based on the printing information to thermally melt the ink ribbon (Ml) by the heat generated by the heat-generating part, and the print head moving means (M4) prints. It works to move the head (M2) in the printing direction and print on the printing paper, and the amount of energization energy that the energization means (M3) supplies to the heat generating part of the print head (M2) is controlled by the energization energy setting means (M5). ) is a value set according to the distance between the heat generating part and the end face. As a result, in the end-face type thermal printer of the present invention, the energizing means (M3) supplies the amount of energizing energy to the heat generating portion according to the distance between the end faces of the print head (M2).

[Example] Next, a preferred example will be described with reference to the drawings in order to further clarify the configuration of the edge type thermal printer of the present invention.

FIG. 2 is an external view of an edge type thermal printer which is an embodiment of the present invention. A keyboard 4 is integrated into the printer unit 2, and the keyboard 4 is provided with various keys including an alphanumeric key 6, and is also provided with a liquid crystal display 8 having a predetermined number of digits, so that characters, symbols, etc. manually entered by the keys can be displayed. is now displayed. Based on the data input from the keyboard 4, printing is performed by the printer section 2.

The printer section 2 includes a carriage 10.

The carriage 10 is supported movably in the x-axis direction (printing direction) along the platen 14 by a guide bar 12, and is connected to a carriage drive motor provided on the printer frame 16 via a drive force transmission bar 18 having a spiral groove. 19 in the χ axis direction. A paper feed roller (not shown) is provided behind the platen 14, and is driven by a roller drive motor (not shown) provided on the frame 16 to feed the printing paper 20 in the y-axis direction.

A thermal head 22 as a print head is held in the carriage 10, and print paper 20 is supplied between this thermal head 22 and a platen 14. Further, a ribbon cassette 24 is removably attached to the carriage 10, and an ink ribbon 26 is routed between the thermal head 22 and the printing paper 20 from there. During a printing operation, the thermal head 22 is pressed onto the printing paper 20 via the ink ribbon 26 by a head pressing motor (not shown) provided in the carriage 10 . The state at this time is shown in the top view shown in FIG.
is mainly a heat generating part 22 on the glaze 22b as a raised part provided at a position away from the end surface 22a on the rear end side in the printing direction of the thermal head 22 in the minute printing direction side.
The ink ribbon 26 is pressed against the printing paper 20 in the section between C and the end surface 22a, and the ink ribbon 26 is peeled off from the printing paper 20 from a point P1 immediately after passing the end surface 22a in the printing direction. Note that the ink ribbon 26 is connected to the heat generating section 22.
C increases the viscosity of the ink layer that is thermally melted, and even if a character is printed by mistake, the same ink ribbon can be used to peel off the character.
It is something that can be erased.

The thermal head 22 is shown as FIG. 3(B) when viewed from the direction of arrow AR in FIG. 3(A>).

As shown in FIG. 3(B), the thermal head 2
The heating section 22G of No. 2 is a heating element 2 made of an electrical resistance element.
It is made up of 26 pieces of 2d arranged vertically. These individual heating elements 22d each correspond to one vertical row of dots constituting characters that are thermally transferred and printed on the printing paper 20.

Next, the electronic control device 30 that controls the edge type thermal printer of this embodiment will be explained.

The electronic control device 30 shown in FIG. 4 is provided within the printer main body.

As shown in the figure, the electronic control device 30 includes a well-known CPU 30.
It is configured as a logic operation circuit mainly consisting of a ROM 30b, a ROM 30b, a RAM 30c, etc., and a timer circuit 30d, an external output circuit 30e, an external input circuit 30f, etc. connected to each other by a bus 30g.

The external output circuit 30e connects the thermal head 22 via the shift register 30h and the energization driver circuit 301.
The heat generating parts 22C1 are connected to the carriage drive motor 19 through the motor driver circuit 30j, and the head crimping motor (not shown) is connected through the motor driver circuit 30k, and the paper feed motor, etc. is connected through the motor driver circuit 301. are connected to each other. Here, the shift register 30h has registers corresponding to the number of heat generating elements 22d of the heat generating section 22C, and sequentially outputs signals according to the pattern of characters to be printed to the energization driver circuit 301. The energization driver circuit 301 energizes each heating element 22d in accordance with the signal output from the shift register 30h. The signal for energizing the heating element 22d is sent to the external output circuit 30e.
When the enable signal output directly to the energization driver circuit 301 becomes high level, the energization driver circuit 301 outputs the enable signal.

The external input circuit 30f of the electronic control device 30 is connected to the keyboard 4 for inputting characters to be printed, a setting switch 35 for setting the energization time to the heating element 22d, and the like.

One end of each of the switches S1 to S4 of the setting switch 35 is pulled up via a resistor R1 to R4, and the other ends of each are grounded. As a result, the boat P connected to the power supply side of each of the switches S1 to S4
1 to R4 indicate a low level when the switch is turned on.

The boats P1 to R4 are each connected to an external input circuit 30f.

The operation of this embodiment having the above configuration will be explained together with the "Printing Control Routine" shown in FIG. 5 and the "Electrification Time T1 Set Processing Routine" shown in FIG. 6.

The "print control routine" shown in FIG. 5 represents the processing executed when characters etc. input from the keyboard 4 are printed on the printing paper 20.

When a printing command is input to the CPU 30a from the keyboard 4 or the like, this process is called after the thermal head 22 is pressed onto the printing paper 20 via the ink ribbon 26.
The CPU 30a first clears the value of the counter DC in the RAM 30C to zero (step 5ioo>. In this embodiment, the characters to be printed are configured as a pattern of 24 dots x 24 dots, and the value of the print dot counter DC is , represents the vertical column in which the dot pattern is printed by the heat generating section 22G.

Subsequently, the CPtJ 30a switches the excitation phase of the carriage drive motor 19 via the external output circuit 30e and the motor driver circuit 30j (step S110).
). As a result, the thermal head 22
4, the character moves in the printing direction by one dot of the character pattern to be printed. After this, the character pattern for one vertical column of characters to be printed is stored in the ROM according to the value of the dot counter DC.
3ob, and outputs the read character pattern (print data) to the energization driver circuit 301 via the external output circuit 30e and shift register 30h (step 5120>).

When the print data is output, through the subsequent steps 5130 to 5160, an enable signal is output directly from the external output circuit 30e to the energization driver circuit 301.
Processing is performed to maintain the high level during the set energization time T1. This energization time T1 is set as follows.

In the thermal head 22 shown in FIG. 3(B), the switch S1 of the setting switch 35 shown in FIG. One of the switches from S4 to S4 is turned on in advance.

That is, as shown in Table 1 below, the end face distance 91 is
When the value is 0 or more and less than the predetermined value 8, switch S1, predetermined value a
When the value is above the predetermined value and less than the predetermined value, the switch S2 is turned on; when the predetermined value is more than the predetermined value and less than the predetermined value C, the switch S3 is turned on; when the predetermined value C is more than the predetermined value, the switch S4 is turned on.

Table 1 CPtJ30a indicates the switch that is in the on state, that is,
The energization time T1 is set according to the boat indicating the low level. That is, as shown in the "energization time T1 setting processing routine" in FIG. When the time is set to a predetermined value t2 (〉tl〉) (steps 5133 to 513
4) When the boat P3 is at low level, the predetermined value t3 (>t
2> (steps 5135 to 3136), while
If a negative determination is made in step 5135, the boat P4 is considered to be at a low level and the predetermined value t4 (>t3) is reached.
(steps 5135 and 5137). This energization time T1 is set in the timer circuit 30d.

Through the above processing (steps 130 to 3160 in FIG. 5), the energization driver circuit 301 turns on only the heating element 22d corresponding to the output print data for the energization time T1. As a result, the ink ribbon 26 is thermally melted in accordance with the print data.

Thereafter, the CPU 30a determines that the total excitation time is T3 (>t4) from the time when the excitation phase of the carriage drive motor 20 is switched in step 5110.
The remaining excitation time T2 is set in the timer circuit 30d so that (step 5170), and wait processing is performed until this excitation time T2 elapses (step 3180).

In the following step 5190, the value of the print dot counter DC is incremented, and then the value of the print dot counter D is incremented.
Determine whether the value of C is 24 (step S200.
). Here, if a negative determination is made, the process proceeds to step 5110.
If the determination is affirmative, it is assumed that printing of one character to be printed has been completed, and the process exits to r RE T U RN J.

Incidentally, the timing chart shown in FIG.
It shows the relationship between the energization timing and the excitation time T3 of the excitation phase switching signal when t1 to t4 are respectively set to predetermined values t1 to t4.

According to this embodiment described in detail above, the end face distance Q1
The energization time T1 of the heating element 22d of the thermal head 22 during printing can be changed according to the value of . As a result, even if the timing of peeling off the ink ribbon 26 from the printing paper 20 differs due to the difference in the end face distance Q1,
An excellent effect is that the energization time T1 of the heating element 22d, that is, the calorific value, can be adjusted to a suitable calorific value according to the end face distance Ω1, and appropriate printing quality can be obtained regardless of the difference in the end face distance Q1. has. Also, as a result,
Even if thermal heads 22 with different end face distances Q1 are used due to production variations, it is possible to always provide an end face type thermal printer with high printing quality.

Next, an edge-type thermal printer according to a second embodiment will be described.

The edge-type thermal printer of the second embodiment has the setting switch 35 used in the edge-type thermal printer of the first embodiment.
The setting switch 35a shown in FIG. 8 is used as the setting switch 35a as shown in FIG. 8, and the "energization time T1 setting processing routine" shown in FIG. 9 is similarly executed as the "energization time T1 setting processing routine" shown in FIG.

Here, the setting switch 35a is set as shown in FIG.
One end of each of the switches Sa1 to Sa8 is connected to a resistor R.
It is pulled up via a1 to Ra8, and the other end of each is grounded. Further, ports Pal to Pa8 connected to the power supply side of each of the switches Sa1 to Sa8 are connected to an external input circuit 30f of the electronic control device 30.

In the end-face type thermal printer of the twenty-first embodiment, the setting switch 35a is set to the average resistance value r of the 26 heating elements 22d made of electrical resistance elements, as shown in Table 2 below.
and the end face distance Q1.

Edge road! When 1tQ1 belongs to the same range of values, the larger the value of the average resistance value r, and when the average resistance value r belongs to the same range of values, the larger the value of the end surface road @Q1, the higher the higher-numbered switch is in the on state. be done.

For example, when the end face path @Q1 is greater than or equal to the predetermined value a and less than the predetermined value S, when the average resistance value r is greater than or equal to zero and less than the predetermined value 6, the switch Sa2 is set to be greater than or equal to the predetermined value d and less than the predetermined value e (
>d) When the value is less than the predetermined value e, the switch Sa3 is opened; when the value is more than the predetermined value e and less than the predetermined value f (>e), the switch Sa4 is opened; when the value is more than the predetermined value f and less than the predetermined value Q (>f), the switch Sa4 is opened and closed. Vessel S
When a5 is equal to or greater than a predetermined value of 9, each switch Sa6 is turned on.

The CPIJ 30a of the device 30 changes the ON state of the switches Sa1 to Se2 to the ON state of each boat Pa1 to Detected and energized via Pa8
Processing is performed to set the value of interval T1.

That is, the energization time T1 is set to a predetermined value ta1 when the boat Pa1 is at the a-level in steps 5210 to 521.
1), when the boat Pa2 is at a low level, the predetermined value ta2
(>tal”) and steps 5212 to 521
3), when the boat Pa3 is at a low level, the predetermined value ta3
(>ta2) and steps 5214 to 5215
>, when boat Pa4 is low level, predetermined value ta4
<>ta3) and steps 5216 to 8217)
, when the boat Pa5 is at a low level, the predetermined value ta5 (>
ta4) and steps 5218 to 5219), when the boat Pa6 is at a low level, a predetermined value ta6 (>t
a5) and steps 5220 to 5221), when the boat Pa7 is at a low level, the predetermined value ta7 (>ta
6) and steps 5222 to 3223), while
If a negative determination is made in step 5222, the ball is 6.
The predetermined value ta8 (>ta
7) (steps 5222 and 5224>).

The edge type thermal printer of the second embodiment has the same effects as the first embodiment, and also has the following effects.

Normally, the thermal head 220 heating element 22d is manufactured with the same resistance value, but due to manufacturing, the resistance value may vary for each head. For example, as a measurement result, a variation in values from about 170 (Ω) to 230 (Ω) has been measured. Therefore, the current supply time T to the heating element 22d
1 being the same, the print quality may be impaired. On the other hand, in this embodiment, a process is performed in which the value of the energization time T1 is changed depending on the value of the average resistance value r of the heating element 22d. This has an excellent effect in that the amount of heat generated by the heating element 22d can be set to a value that enables high-quality printing, regardless of variations in the resistance value of the heating element 22d.

Next, an edge-type thermal printer according to a third embodiment will be explained.

The end face type thermal printer of the third embodiment executes the "energization time T1 setting processing routine" shown in FIG. 10 as the "energization time T1 setting processing routine" shown in FIG. 9.

In the edge type thermal printer of the third embodiment, the eighth
The setting switch 35a shown in the figure is shown in Tables 3 and 4 below.
Set according to the table.

That is, as shown in Table 3, the switches Sa1 to S
For e4, as in Table 1 of the first embodiment, the switch to be turned on is set depending on the value of the end surface pressure IH1. Also,
As shown in Table 4, when the average resistance value 22d of the heating element 22d is greater than or equal to zero and less than the predetermined value 61, the switches Sa5 to Se2 are switched to the predetermined value 01 or more and less than the predetermined value. When less than e1 (>l), switch Sa6
When is greater than or equal to a predetermined value 01 and less than a predetermined value f1 (>el), the switch Sa7 is turned on, and when it is greater than or equal to the predetermined value f1, the switch Sa8 is turned on.

The CPU 30 of the electronic control device 30 shown in Table 3 and Table 4 and FIG.
According to the process of "energizing time T1 set processing routine" shown in the figure, the ON state of the four switches Sa1 to Sa8 is detected via each port Pa1 to Pa8, and the energizing time T1 is set.
Set the value to 1.

That is, when port Pa1 is at a low level, table E1 shown in Table 5 below should be selected in steps 5230 to 5.
231), when port Pa2 is at low level, select table E2; steps $232 to 5233>;
When port Pa3 is at a low level, table E3 is selected (steps 5234 to 8235); on the other hand, when a negative determination is made in step 5234, port P
Considering that a4 is at a low level, table E4 is selected (step 236). After that, when the port Pa5 is at a low level, the first data of the selected table is set as the energization time T1, and steps 5237 to 523
8) When port Pa6 is at low level, set the second data of the selected data as the energization time T1. Steps 5239 to 5240>, When port Pa7 is at low level, set the third data of the selected table. The energization time is set to T1, (steps 5241 to 5242>,
On the other hand, if a negative determination is made in step 5241, the port Pa8 is considered to be at a low level and the fourth data in the selected table is set as the energization time T1 (step 8243). As a result, in this embodiment, as shown in Table 5, the energization time T1 can be set in 16 levels.

The edge-type thermal printer of the third embodiment in Table 5 has the same effect as the edge-type thermal printer of the second embodiment, and also has an energization time T1 based on the edge distance Q1 and the average resistance value r of the heating element 22d. can be set more precisely, and the printing quality can be further improved.

The edge-type thermal printer of the present invention is not limited to the above-mentioned embodiment in any way, but can be implemented in various forms without departing from the gist of the present invention. For example, in the second and third embodiments, the energization time T1 is set according to the average resistance value r of the heating elements 22d, but the energization time of each heating element is set according to the value of each heating element 22d. It may be configured to set. This results in
This has the effect of further improving printing quality.

According to the edge type thermal printer of the present invention, it is possible to change the amount of energization energy during printing with the edge type thermal head according to the value of the edge distance. As a result, even if the timing of peeling off the ink ribbon from the printing paper differs due to differences in the end distance, the amount of heat generated by the heat generating section can be adjusted to a suitable amount of heat according to the end distance. It has an excellent effect of being able to obtain appropriate print quality regardless of the Moreover, as a result, even if edge-type thermal heads with different edge distances are used due to production variations, an excellent effect is achieved in that an edge-type thermal printer with high printing quality can always be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the basic configuration of an edge-type thermal printer according to the present invention, FIG. 2 is an external view of an edge-type thermal printer according to an embodiment of the present invention, and FIG. 3 (A> and (B))
are explanatory diagrams showing the thermal head 22, FIG. 4 is an electric circuit diagram centered on the electronic control unit 30, FIG. 5 is a flowchart showing the processing of the "print control routine", and FIG. 7 is a timing chart showing the timing of the energization time T1 and the excitation phase switching signal, FIG. 8 is a circuit diagram showing the setting switch 35a of the second embodiment of the present invention,
FIG. 9 is a flowchart showing the processing of the "energization time T1 setting processing routine", and FIG. 10 is a flowchart showing the processing of the "energization time T1 setting processing routine" executed in the third embodiment of the present invention. 2... Printer section 4... Keyboard 20... Print paper 22... Thermal head 26... Ink ribbon 30... Electronic control unit

Claims (2)

[Claims] (1) It has a heat-melting ink ribbon and a heat generating part made of an electrical resistance element near the end face away from the end face on the rear end side in the printing direction toward the minute printing direction side, and the heat generating part causes the ink ribbon to be heated. a print head that prints by pressing onto a printing paper and thermally melting an ink ribbon by the heat generated by the heat generating part; an energizing means that energizes the heat generating part of the print head based on print information; Accordingly, in an edge type thermal printer equipped with a print head moving means for relatively moving the print head in the printing direction, the amount of energization energy supplied to the heat generating part by the energizing means is set to be equal to the amount of energy supplied to the heat generating part by the heat generating part and the end face. An end-face type thermal printer characterized in that it is equipped with an energization energy setting means that sets the energization energy according to the distance from the printer. (2) The energization energy setting means is configured to set the energization energy amount according to the distance between the heat generating part and the end face and the resistance value of the heat generating part. The edge-type thermal printer described in item 1.