JPS6092879A - Thermal printer - Google Patents

Abstract

PURPOSE:To prevent the temperature of an end point from being lowered and prevent an end point or an isolated point from being printed unclearly, by a method wherein an end point (isolated point) in a printing pattern is detected, and an electric current is passed for a longer period of time or temperature is raised when a peripheral part of the end point has not been printed until the printing two times earlier. CONSTITUTION:When printing a straight line form by a printing pattern of dots 4-16 indicated by shaded parts in a register R1, upper and lower end points E1, E2 are extracted by an end point detecting part ED, are set on a register R2, and then whether the current-passing period of time is to be prolonged is discriminated by an end point current passing discriminating part TD. For this discrimination, printing data d2 for the preceding printing and printing data d1 for the printing before the preceding printing are read from a printing data buffer, and it is detected whether or not printing has been conducted in the region of each two dots on the upper and lower sides of the end point E1. When one of these dots has not been printed, the current-passing period of time is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thermal printer, and more particularly to a thermal printer in which end points and isolated point portions can be printed with good print quality to improve print quality.

[Technology background]

For example, thermal printers are used as output devices for data processing devices such as word processors. There are two types of thermal printers: a color-producing type that uses paper coated with a heat-sensitive coloring agent that colors when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal printer that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated, and a thermal type that uses paper coated with a heat-sensitive coloring agent that develops color when heated. There is a transfer type that uses a thermal ink φ ribbon coated with ink. In such thermal printers, in the case of a serial type having a serial head, the thermal printer is provided in the thermal head. By selectively energizing necessary heating elements among a plurality of heating elements arranged in the vertical direction, arbitrary printing is performed while moving the thermal head.

At this time, the printing density is determined by the temperature of the heat generating part of the thermal head.

FIG. 1 shows a part of an alK transfer type thermal printer.

A normal paper 2 is placed on a platen 1, a thermal ink ribbon 5 is placed on it, and a thermal head 4 prints on it. This thermal head 4 has a first
As shown in the figure (bl), an elongated heat generating section 5 is provided. Characters, symbols, figures, etc. can be printed by heating.

[Conventional technology and problems]

By the way, when using such a serial type thermal printer, as shown in Fig. 1 (el K), when printing vertical ruled lines, the connected part may be printed in a disconnected state, or the same ( As shown in fl, there is a problem that the print quality is partially poor, such as the isolated point P being printed thinly.The reason for this is.

For example, when printing a vertical line in Figure 1 (cl. This often causes a disconnection condition.And the reason why this phenomenon occurs is that even if each heating element is energized at the same time,
It was found that this is because a temperature difference occurs due to the influence of adjacent heating elements, etc., and the temperature at the end point portion decreases.

The same reason applies to the deterioration of print quality at the isolated point P shown in FIG. 1 (fl).

In other words, the print control of this type of conventional thermal printer is as follows:
This is because, as shown in FIG. 2, when printing the print data, the 9 energization time control section uniformly controls the energization time to the heating element of the thermal head for each driver.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal printer that improves the above-mentioned problem that the print quality at end points and isolated points in this type of thermal printer may deteriorate.

[Structure of the invention]

To achieve this object, the thermal printer of the present invention includes a thermal head having a plurality of heating elements arranged adjacent to each other, and means for moving the thermal head relative to a print medium.

An end point detection unit that detects an end point or an isolated point of a printed pattern; and three means for detecting the presence or absence of a printed pattern near an end point or an isolated point from a print pattern printed before the point of printing a nuclear end point or an isolated point. , and means for controlling the amount of heat generated by the heating element corresponding to the end point or isolated point depending on the presence or absence of a printed pattern in the vicinity of the end point or isolated point.

[Embodiments of the invention]

Before describing the present invention in detail based on one embodiment, an outline thereof will be explained. In the present invention, an end point (isolated point) in a printing pattern is detected, and when the peripheral part of this end point has not been printed in the previous printing, the energization time is lengthened or a higher temperature is generated. Control to get. This makes it possible to prevent a drop in temperature at the end points (isolated points), thereby preventing the deterioration of print quality as described above.

An embodiment of the present invention will be described based on FIGS. 3 to 27.

The external appearance of the thermal printer of the present invention is shown in FIG.

In FIG. 3, the paper 2 is inserted through the insertion opening of the upper cover 10, and the printed material is received from the paper holder 11. Figure 4 explains the inside of a thermal printer, in which a thermal ink ribbon 12 is used.
A space motor 13 controls the movement of a carrier 15 having a thermal head 14 . The thermal printer has an internal line feed motor (LP) for paper feeding, and an approach that controls the approach between the paper and the core ribbon so that the thermal ribbon does not stick to the paper as it is fed. - Mechanisms (not shown) such as an escape motor (AE) are installed. Note that FIGS. 3 and 4 show examples of transfer type thermal printers.

Next, an outline of the control according to the present invention will be explained.

For example, as shown in FIG. 5, when printing in a straight line with a printing pattern indicated by dots 4 to 16 as shown by the diagonal lines in register R1, the end point detection unit EDK performs the operation described in detail later. Upper and lower end points of the printing pattern Ely
g, and set it in register R2. The end point energization determination section TD shown in FIG. 7 then determines whether the energization time for this end point E1+g is to be as normal or longer than normal.

This energization time determination is performed using the previous print data d stored in the print data buffer BU and the print data d before the previous time when the end point to be judged is a crow, as shown in FIG. 6.
, and it is checked whether or not there has been printing in an area of two dots each on the upper and lower bases with respect to the end point E1. That is, a total of 10 dots from ■ to 00 in the check area CH in FIG. 6 are checked. If there is no printing for 1 bit within this check area CH, a determination is made to increase the energization time at the end point E. However, 1 in this check area CH
If printing is performed even with bits, the energization time of the end point bird will not be increased and heating will be performed in one normal energization time.

Therefore, as shown in FIG.
+ Check the print data from the previous time and the print data from the previous time as shown in R14. Regarding the end point E1, there is no print data in the check area CHl, but the end point B2
Since print data exists in the check area CH, in this case, the end point energization determination unit TDilt determines to lengthen the energization time only for the end point E, and outputs the determination result to the register Rtl. As a result, control is performed to lengthen the energization time for the end point E.

FIG. 8 is a pull diagram of the thermal printer of the present invention. In FIG. 8, 20 is an MPU (microprocessor), which is a general control unit for this thermal printer, 21 is a ROM, which stores programs necessary to operate the MPU 20, and 22 is a RAM, which is a general control unit for this thermal printer. 26 is an input/output port that is used to hold input data and as a data processing register for the operation of the MPU 20, and is used to connect this thermal printer with an external device. 24 is an output port for inputting printing data to be printed and outputting a report signal for reporting printing results, and 24 is an output port for various devices used in the thermal printer.

Example Evaspace Motor 13. thermal head 14,
Ab p-chi escape Φ motor 27. Buffers 26-1 to 26- that control line feed motor 2B%
4, and 25 is an input port into which signals from various sensors, response switches, etc. built into the thermal printer are input. An approach detection microswitch 50 detects whether the thermal head 14 is in such a state, that is, how far down the thermal head 14 is and how far it is up. A left end sensor 31 that detects whether the carrier 15 is located at the left end.
Paper set sensor 32 that detects the presence or absence of paper 2. An output signal from a ribbon end sensor 33, etc., which detects whether the thermal energy ribbon is in the ribbon end state using a silver paper or the like provided at the final end of the ribbon is input. Among these, the left end sensor 51. Paper set/
Since the sensor 32 and the ribbon sac end Φ sensor 33 are composed of photo sensors, detection signals amplified by the respective amplifiers 29-1 to 29-3 of the photo amplifier 29 are input.

Next, the operation shown in FIG. 8 will be explained.

When print data is transmitted from the host device to the input/output board 26, the MPU 20 stores the data in the RAM 22, and then prints the thermal data according to the control instructions in the ROM 21.
Printing is performed by supplying print data line by line to the head 14. At this time, the left end sensor 51 detects whether the thermal head 14 is initially located at the left end, and thereafter the space motor 16 sequentially drives the thermal head 14 in the printing direction. When one line of printing is completed, the approach/escape motor 27 moves the thermal head 1
4 off the paper, the space e motor 13 moves the thermal head 14 and the thermal ink ribbon together to the left end to print the primary line.

Of course, at this time, the line feed motor 28 feeds the paper. When the paper runs out, this is detected by the paper set sensor 32, and the thermal ink sensor 32 detects this.
If the ribbon needs to be replaced.

The ribbon end sensor 36 detects this and reports it to the MPU 20, respectively.

By the way, as shown in FIG. 9, the MPU 20 has an end point detection section 40. End point energization determination section 419 energization time control section 42. A register section 43 and the like are provided.

The configurations of the end point detection section 40 and the end point energization determination section 41 will be described in detail later.

For example, end point detection is performed in the end point detection unit 40 for input data as shown in FIG. 5, and the end point E1. E.

is detected, and the end point energization determination unit 4 is detected in the state shown in FIG.
When it is determined that the energization time of the terminal point El should be lengthened, the registers 1 to 1 of the register R1 in FIG.
Printing control is not performed for 3 dots, and for 5 to 16 dots, the energization time T is the same as before. The power supply to the heat generating element of the thermal head is controlled at , but for the fourth dot, the heat generating element is energized for a time extended by △T before and after To, so the temperature drop with respect to this end point E1 is This will prevent printing with the correct density and shape. In addition, FIG. 10 is for comparison with the present invention,
The conventional energized state is shown. In the conventional case.

Uniform T for character pattern parts regardless of whether there are endpoints or not. Since the heating element is controlled by the energization time, the 10th
As shown in the figure, no current is applied to dots 1 to 3, and dots 4 to 3 are not energized.
The energizing time is T for all 16 dots. This indicates that energization is controlled by .

By the way, as shown in FIG. 12, the thermal head 14 is provided with 16 heating elements h1 to h1g corresponding to each dot, and each heating element has a driver (transistor having a Darlington circuit configuration) D1 to D on one side. □6 is connected. Therefore, by selectively inputting a pulse signal to this driver, each heating element generates heat for a time corresponding to the pulse width.

In addition, the space motor 13 uses four-phase pulses from A phase to D phase.
Selectively on/off control of drivers (transistors with Darlington circuit configuration) D4 to Dd, which are composed of a motor and connected to each phase coil A to D, respectively.
As a result, current flows selectively to the coils A to D of each phase 2, resulting in control in a 1/2 phase system, as shown in FIG. 14, for example.

When the space motor 13 is started, the human phase is excited for a long time, and then the excitation time is sequentially shortened to AB phase, B phase, BC phase, etc., and after this acceleration period has passed, the printing speed is constant. be driven. During this constant speed operation, A phase, AB phase, B phase
Controlled by phase... and 1/2 phase system. and,
As shown in FIG. 15, the thermal head is energized based on the phase switching point of the space motor. The heating element of the thermal head is energized at a time t after the phase change, but when end point energization control is performed, it is applied b (b>t2) after the phase change. Power is started.

Next, the characteristic end point detection control and end point energization determination control of the present invention will be explained.

The end point detection control and the end point energization determination control are performed by the end point detection section 4o, the end point energization determination section 41o, as shown in FIG. bii
1/(buffer BU1 to third buffer BU5. First processing register r to fourth processing register r4, etc.) By setting the print data obtained as a result of processing to the output port p, the thermal head is Turn on electricity.

A. First, two embodiments of end point detection processing will be described.

fi+ End point detection processing (first embodiment) 'In this first embodiment, as shown in FIG.
~Use third processing register r3. This first processing register r1 is configured to output a carry.

As shown in the flowchart of FIG. 18, the third processing register r3 is cleared and the current print data set in the primary $3 buffer BU3 is transferred to the first processing register "□. At this time, the first processing register r1 If the print data set in is not all rOJ, the second processing register r
Enter rooolJ in hexadecimal in 2. As a result, the second
The least significant bit 1 of the processing register r2 is set to "1", and the state shown in FIGS. 17 and 19 (al) is entered.

In this state, the first processing register r1 is loaded to the right. At this time, if the first processing register r1 does not output a carry, the second processing register r2 is rotated to the left. As a result, the first processing register rI and the second processing register r2 are overwritten as shown in FIG. 19 (bl).

This loads the first processing register r1 to the right. At this time as well, no carry is output, so the second processing register r2 is loaded to the left, resulting in the state shown in FIG. 19 (cl).Then, the first processing register r1 is loaded to the right, but no carry is output, so The second processing register r2 is also rotated to the left. In this way, the state shown in FIG.
), carry cR-rB from the first processing register r□.
is output, so at this point the data of the second processing register r2 is set to the sixth processing register r3 VC. At this time, as shown in FIG. 19 fal, the second processing register r2
Since "1" exists in bit 4, this is the upper end point E set in 61S3 buffer BU5,
It shows.

Next, the data of the third buffer BU3 is set in the first processing register r1 again, and the second processing register r2 is set to r8000j in hexadecimal, that is, "100..." in binary.
...00" is set. As a result, the first processing register r1 and the second processing register r2 are
The data is set to the state. Then, the first processing register r0 is now loaded to the left. At this time, a carry C is sent from the first processing register r1 as shown in FIG.
Since R-rIJ is output, the data set in the second processing register r2 at this time indicates the lower end point, so the current print data set in the third buffer BU3 is changed from the state of the second processing register r2. It can be seen that the lower end point of is the most significant bit 16.

(2) Endpoint detection processing (second embodiment) A second embodiment of endpoint detection will be described with reference to FIGS. 21 and 22. In this second embodiment, the print data held in the third buffer BU3 is set in the first processing register rl, and the initial value is set in the fourth processing register r4 used as a counter, and the first processing register r is rotated. Each time a carry is output, it is incremented by +1 or -1, and this continues until the carry is output. This will be explained below with reference to the flowchart of FIG.

First, the second processing register r to the fourth processing register r4 are cleared, and the print data written in the sixth buffer BU3 is transferred to the first processing register rl.

At this time, if the print data set in the first processing register r1 is not all "0", "1" is added to the fourth processing register r4. As a result, the numerical value 1 is written into the fourth processing register r4. In this state, the first processing register r1
Rotate to the right. If a carry is not output from the first processing register r1 at this time, the fourth processing register r4 is further incremented by +1. Then, the first processing register r1 is rotated to the right.

Carry C from the first processing register r1.
Repeat until R-rIJ is output. and carry C
When R=rIJ is output, the numerical value written in the fourth processing register r4 indicates the position of the upper end point of the print data set in the sixth cross BU3. In the example of FIG. 21, when the first processing register r1 is rotated to the right four times, carry CR=r1J is output, so
At this time, the number "4" written in the fourth processing register r4
indicates the upper end point of this print data. Therefore, for the third processing register r3, this fourth processing register r
By setting the bit that corresponds to the count value of 4 to "1", the upper end point can be set in the third processing register r.

Once the upper end point is set in this way, the lower end point is then set. Therefore, the print data set in the third buffer BU3 is set again in the first processing register r1, and the value 17 is initially set in the fourth processing register r4. This numerical value 17 indicates a value obtained by adding 1 to the number of pits in one column of print data. Next, the value set in the fourth processing register r4 is decremented by 1, and then the first processing register r1 is loaded to the left. At this time, carry CR-rIJ is output, so at that time the value counted by the fourth processing register [4 (at this time, 17-1-I
The bit of the second processing register corresponding to S) is set to "1". The 16th bit of the second processing register r is set to "1", and this indicates the position of the lower end point.

B. Two embodiments of end point energization determination control will be described.

111 End point energization determination control (first embodiment) In this first embodiment, as shown in FIG. BU2 and the first to third processing registers r1 to r are used. In this case, Mori sets the lower end point E2 in the second processing register r2.

The upper end point E is set in the third processing register.

■ Figure 24 (as shown in the 70-chart in al.

Upper end point E of third processing register rl! is transferred to the first processing register r. Then, the previous print data of the first buffer BU1 and the data of the first processing register r1 are ANDed for each bit, and the result of this operation is set in the first processing register r1. Then, it is determined whether this is all zero or not. In this case, the print data from the time before last is shown in Figure 7L.
-1, and the first processing register r1 contains bit 4.
Only "1" indicating the upper end point E1 is written in the position of , and the other bits are 1 to 3 and 5 to 16 UrOJ. Therefore, the AND of each bit of the first processing register r1 and the first buffer BU1 is "0". What if "1" is output as a result of this logical product?

"1" exists in bit 4 of the print data from the previous time, indicating that it was printed and heated, so in this case, E
There is no need to lengthen the energization time of l, and the upper end point E1 set in the third processing register r3 is cleared.

■ Next, the upper end point B of the third processing register r.

is set in the first processing register r1, and this time, it is ANDed with the 's2 buffer BU2 in a bit-corresponding manner, and the operation result is set in the first processing register r. As a result, “1” is bt′
LF! The third processing register r8 is cleared if the previous print data of the second buffer BU2 is shown in the register R8-3 in FIG.

It will be all rOJ.

(2) Next, it is checked whether print data exists in areas (2) and (2) in FIG. Therefore, the upper end point E of the third processing register is set in the IJ1 processing register r1, and this is first loaded by one bit to the left. Then, the first processing register r and the gK1 buffer BU1 are logically ANDed, and this operation result is set in the first processing register rl. If this is "0", the upper end point E1 of the sixth processing register r is set to the first processing register rl. 1 processing register rIK is set, this is set to the left by 1 pit load shift, the logical product of the second buffer BU2 is performed, and the result of this operation is set in g11 processing register r1. If this is "0", check the areas (2) and (2) in FIG. 6 in the next step (2).

■ Therefore, the upper end point B of the third processing register r3.

The first processing register r! Set it to 2 to the left.
Bit rotation is performed, and the result of the logical AND operation with the first buffer BU1 is set in the first processing register r1.

If this is "0", the upper end point E8 of the third processing register r is set to the first processing register rl_tfc again, and this is rotated 2 bits to the left.

This time, perform a logical product with the second buffer BU2, set the result of this operation in the first processing register r1, and determine whether this is "0" or not. If this is "0", in the next step (2), the areas (2) to [stock] in Figure 6 will be checked.

■ Similar to the above ■ to ■, transfer the upper end point E1 of the third processing register r3 to the first processing register r1, and this time rotate it to the right by 1 bit, and compare it with the first buffer BU1 and the second buffer 7BtJ2. Compute the logical product. If at least one of these operation results is "0", the upper end point E1 of the third processing register r3 is cleared, but both of them are "0".
0'', transfer the upper end point B8 of the third processing register r3 to the first processing register r1, rotate it to the right by 2 bits, and move the upper end point B8 of the third processing register r3 to the first buffer BU1. A logical product is calculated with the second buffer BU2, and similar processing is performed. In this way, if the calculations regarding the upper end point E1 are all "0", 'I
J3 processing register rsK is written in the upper end point E! Leave it as it is and now lower end point B! Shifts to end point energization determination control.

■ This time, as shown in the 7m-chart in Figure 24 (bl), the lower end point B2 is entered in the second processing register r2.
Set the data in the first processing register r1.

A logical product is calculated with the previous print data set in the first buffer BU1. If the print data from the previous printing has been set in registers R1-8 in FIG. 7, "1" exists in this calculation result.

The second processing register r2 is cleared to erase the data at the lower end point E2, and the energization time is not extended when printing at the lower end point E2.

However, if this logical product is "0", the data of the lower end point E2 of the second processing register r2 is set in the first processing register r1 again, and the previous print data set in the second buffer BU2 is Calculate the logical product with. This is also “0”
'', the data of the lower end point E of the second processing register r2 is set in the first processing register r1 in the same manner as in the case of ■ to
Shift bits to the left or right and perform a logical AND with the first buffer BU1 or the second buffer BU2. If the result of any of these checks is "1" at least once.

Clear the second processing register r. However, both “
0'', it is determined that the energization time should be extended for this lower end point E3.

■ Logically OR the data of the lower end point E3 set in the second processing register r and the data of the upper end point E set in the third processing register r, and add this to the first processing register. Set to rl.

Then, only the end point written in this first processing register r1 is determined to be the one whose energization time should be extended, and control is performed.

By the way, the procedure shown in Fig. 24 (al, lbl) is based on the basic idea, but it takes a long time to process because it repeats simple processing.Therefore, by adding one processing register, The processing time can be greatly reduced by using the procedure of checking the 10 dots in the check area shown in Fig. 6 all at once.Next, this is done in Figs. 25 and 26 (ia) + (b).
A second embodiment of end point energization determination control will be described based on 1. In this second embodiment, window data is created in the fourth processing register r4 from the end point data of the second processing register r2 or the sixth processing register r3, and the data set in the first buffer BU1 and the second buffer BU2 are set in the previous two buffers. .

The previous print data is summarized as a logical OR and transferred to the first processing register r1, and the first processing register r1 and the fourth processing register r4 are checked.
The judgment is done separately at the upper and lower ends.

(2) End point energization determination control (second embodiment)■ First, the sixth
The data at the upper end point E8 of the processing register r is set in the first processing register C and the fourth processing register r4. Then, the first processing register r is rotated to the right by one bit. In this state, the first processing register r1 and the fourth
The logical sum of the data with the processing register r4 is calculated and the result is written into the fourth processing register r4.

(2) After the above calculation is completed, the first processing register r1 is refreshed by 1 bit load to the right. In this state, the logical sum of the data of the first processing register r1 and the fourth processing register "4" is calculated and written in the fourth processing register r4.

(2) Next, the data at the upper end point E1 of the fifth processing register r is set in the first processing register r1 again, and this time it is rotated 1 bit to the left. In this state, the result of the logical sum of the first processing register r1 and the fourth processing register r4 is written into the fourth processing register r4.

(2) After the operation in (2) is completed, the $1 processing register r1 is further loaded 1 bit to the left. The logical sum of the first processing register r1 and the fourth processing register r4 is determined and written into the fourth processing register r4.

In this way, the upper end point E is stored in the fourth processing register r4.
``1'' is written in the area of two dots on the left and right, including ``1''.

■ Then, transfer the print data from the previous printing set in the first buffer BU1 to the first processing register r1, perform a logical sum on this data and the data in the second buffer BU2 in a bit-corresponding manner, and use the result of the operation in the first processing register r1. Fill in.

■ This first processing register r and the data of the js4 processing register r4 in which the operation result of the above (■) has been written are logically ANDed in bit correspondence, and the result of the operation is transferred to the first processing register r8.
Set to . At this time, if print data from the previous or previous printing exists in the 10-bit check area indicated by CH in FIG.

Since "1" exists in the result of this calculation, the upper end point B8 set in the sixth processing register r3 is cleared at this time, but if there is no print data, the result of this calculation will be all "0". , upper end point B.

It is determined that the energization time should be extended.

Since the determination regarding the upper end point El is completed in this way, the determination regarding the lower end point E2 shown in FIG. 26 tbl is now performed.

■ For the judgment on the lower end point 'B2, set the data of the second processing register r2, in which the lower end end point E2 is written, in the first processing register r1 and the fourth processing register r4, respectively, and then perform the judgment on the upper end point El. Since the steps are the same, the details will be omitted. As a result, if the lower end point E2 does not require an extension of the energization time, the second processing registration error r2 is cleared.

■ When the determination regarding the upper end point E1 and the lower end point E2 is completed in this way, ! The logical OR of each data in the 42 processing register r2 and the third processing register r3 is calculated,
The result of the calculation is set in the first processing register r1.

In this way, the end point energization time is extended only for the data that is finally stored in the first processing register r□.

For example, when printing [HJ] using the thermal printer of the present invention, as shown in FIG. Correct printing with excellent print quality can be performed.

In the present invention, as shown in FIG. 11, when extending one energization time, it is desirable to extend the period by ΔT before and after one normal period. This is to avoid the possibility that when it is extended only to the front or back, there will be a slightly protruding part on the extended part, which may result in an unnatural printing form.

〔Effect of the invention〕

According to the present invention, end points and isolated points are extracted, and these parts are printed by controlling the energization time to be extended based on the previous printing conditions, so that missing end points and isolated points are thin. condition can be improved. Therefore, it is possible to provide a thermal printer with excellent printing quality.

[Brief explanation of the drawing]

Figure 1 (at, (bl) is an explanatory diagram of the printing part of a thermal printer, tcL (dL (ef) (rl is an explanatory diagram of the problems of a conventional thermal printer, and Figure 2 is an explanatory diagram of the head control state of a conventional thermal printer. , FIG. 3 and FIG. 4 are configuration diagrams of the thermal printer, FIG. 5 is an explanatory diagram of the end point detection state, FIG. 6 and FIG. 7 are explanatory diagrams of the end point energization determination state in the present invention, and FIG. A schematic configuration diagram, FIG. 9 is a detailed view of the main parts of the present invention, FIG. 10 is an explanatory diagram of the operation of a conventional thermal printer, FIG. 11 is an explanatory diagram of the operation of the thermal printer of the present invention, and FIG. 12 is a line thermal head control. Part, 1st
3 is a space motor control section, FIG. 14 is an explanatory diagram of the space motor control state, FIG. 15 is an explanatory diagram of the thermal head energization state, FIG. 16 is a configuration diagram of the main parts of the present invention, and FIGS. 17 to 20 are End point detection first embodiment explanatory diagram, Fig. 21, Fig. 22
The figure is an explanatory diagram of the second embodiment of end point detection, and FIG. 26 shows the buffers and registers used in the first embodiment of end point energization determination.
Fig. 24 is an explanatory diagram of the operation of the first embodiment of end point energization determination, Fig. 25
The figure shows a buffer and a register used in the second embodiment of end point energization determination. FIG. 26 is an explanatory diagram of the operation of the second embodiment of end point energization determination. FIG. 27 is an explanatory diagram of a printing state in the present invention. In the figure, 1 is a platen, 2 is paper, 6 is a thermal ink ribbon, 4 is a thermal head, 5 is a heat generating section, 10 is an upper cover, and 11 is a paper holder. 12 is a thermal ink ribbon, 13 is a space motor, 14 is a thermal head, 15 is a carrier, 20
is a microprocessor, 21 is a ROM, 22 is a RAM,
23 is an input/output port, 24 is an output port, 25 is an input port, and 26 is a driver. 27 is an approach-escape motor, 28 is a line number feed Φ motor, 29 is a photo amplifier, and 30 is a microswitch for approach detection. 31 is a left end sensor, and 32 is a paper set sensor. 33 is a ribbon end sensor, 40 is an end point detection section, 4
Reference numeral 1 denotes an end point energization determination section, 42 an energization time control section, and 43 a register section. Patent Applicant Fujitsu Ltd. Representative Patent Attorney Akira Yamatani Figure 5 Figure 71 Rt-l/? l-2Rt-s/? 2-1 1~3 dots □ I~3 dots Figure 12 Figure 16rgJ Figure 17 Figure 23 [Do! Zμ stop--r3 Fig. 24 (0) Fig. 24 (b) Fig. 265A (on Fig. 26 (b) Fig. 27

Claims (1)

[Claims] A thermal head having a plurality of heating elements arranged adjacent to each other, means for relatively transporting the thermal head with respect to a printing medium, and an end point or an isolated point of a printing turn. and an end point detection section that detects. means for detecting the presence or absence of a printed pattern near the end point or isolated point from a print pattern printed before the end point or isolated point; 1. A thermal printer comprising: means for controlling according to the presence or absence of a print pattern near an isolated point.