JPH05278248A - Recording method in thermal line printer - Google Patents

Abstract

PURPOSE:To reduce an occurrence of sticking by a method wherein in a record ing method in a thermal printer conducting thermal recording, a time from the completion of heating to the start of paper feeding is shortened by feeding paper by a slight amount smaller than the size of a heating element during a one-line recording. CONSTITUTION:For example, (A) one-byte data is transmitted to a shift register until a simultaneous heating dot count comes to zero; (B) space data for unprocessed bytes out of 64 bytes is transmitted to the shift register; (C) heating is carried out; and (d) space data for processed bytes is transmitted to the shift register. When a byte counter reaches '32' by repeating a sequence (A)-(D), i.e., when the 1st-31th bytes corresponding to 256 dots, i.e., the half of 512 dots, are completely processed, space data for 32 bytes is transmitted similarly to the processing (B). Upon completion of the previous heating, paper is fed by 1 step. By setting one step to be 0.5 dot, a deviation between the former 256 dots and the latter 256 dots caused by the paper feeding is made as inconspicuous as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method for a thermal line printer for performing thermal recording.

[0002]

2. Description of the Related Art In recent years, with advances in technology, computer devices have become smaller and smaller, and products with a size that can be held with one hand, such as handy terminals, have been introduced. One of the themes of these products is to miniaturize the printer because it is necessary to print out a part or all of the information content while carrying it, depending on the work used.

A printer used in these portable computers is a thermal line printer. A thermal line printer electrically heats a heating element of a recording head, and the heat causes the heat-sensitive paper coated with a chemical to partly discolor and print. Since the thermal line printer is simple in principle and requires a small number of parts, it is advantageous in miniaturizing the apparatus. However, the chemical applied to the thermal paper has the property that it discolors and solidifies when it cools down, and this property causes a force to bond the recording head and the thermal paper, which causes resistance to the paper feed force. May be. This phenomenon is called a stick, which hinders smooth paper feeding and causes uneven printing.

In order to prevent the stick, it is sufficient to increase the paper feeding force.
A first method is known in which the friction coefficient of the platen roller used for feeding the paper is increased or the motor for driving the platen roller is made to have a large torque.

Further, the longer the time from the end of heating of the thermal line head to the start of paper feeding, the more the cooling and solidification of the discolored chemical proceeds, and sticking is more likely to occur. Therefore, as a method of eliminating the cause of occurrence of this stick, when printing the recording information for one line, the thermal line head is not heated in several parts but is heated simultaneously for one line. so,
A second method is often used in which the time from the end of heating to the start of paper feeding is shortened.

However, in the above first method,
Increasing the friction coefficient of the platen roller means roughening the surface, which may damage the thermal paper, and increasing the motor torque increases the torque.
A large motor is used, which is disadvantageous for downsizing.

In the second method, when one line is heated at the same time, the power consumption of the battery is increased and the printing amount that can be charged by one charge is reduced. .. This point will be described in detail.

As shown in FIG. 12, in a thermal printer unit having 384 heating elements in 6 blocks (1 block = 64 dots) controlled by 6 strobe signals (head energization signals), the number of simultaneous heat dots (maximum) Value) = 64 dots. The total of the black dots of the dot line 1 shown in FIG. 13 is 60 dots (the portions corresponding to blocks 1 to 6 are 10 dots each), and the total of the black dots of the dot line 2 is 110 dots (the block 1
= 40 dots, block 2 = 30 dots, block 3 =
10 dots, blocks 4 and 5 = 5 dots, block 6 =
To obtain a print result that is 20 dots),
14 is controlled at the timings A to E shown in FIG.

Here, A: data for printing at a timing of stop state B for one dot line,
Transfer to the thermal head shift register.

B: Print data output of dot line 1 Ba: Print data for one dot line transferred by A is latched (stored) in the latch register of the thermal head.
Then, the strobe signal (DST
Signal) starts energizing the thermal head. As described above, the total number of heat dots is 60, which is less than the above number of simultaneous heat dots, so printing is performed once.

Bb: The print data for the next one dot line is transferred to the head.

C: Paper feeding B-a, after which the motor is driven to feed one dot of paper.

D: Print data output of dot line 2 The print data for one dot line transferred at the timing of B-b is latched (stored) in the latch register of the thermal head, and a strobe signal (64 dots as one unit) ( Energization of the thermal head is started by the DST signal). As described above, the total number of heat dots is 110 dots, which is larger than the number of simultaneous heat dots described above, so 60 dots (DST 1, 3, 4, 5) and 50 dots (DST).
Print in two steps (2, 6).

E: Paper feeding After the timing of D, the motor is driven to feed one dot of paper.

[0015]

However, in the above-mentioned conventional example, power is supplied (heated) by six strobe signals.
The control has the following drawbacks.

(1) When printing one dot line in multiple divisions as in the case of the timing D, it is necessary to manage the heating order for each strobe.

(2) In the above-mentioned conventional example, the number of dots controlled by one strobe = the number of simultaneous heat dots, but in the case of the number of dots controlled by one strobe> the number of simultaneous heat dots, in addition to the above (1) Therefore, it is necessary to manage division within one block managed by one strobe.

(3) In a portable computer, miniaturization by high-density mounting is important, but having a plurality of strobe signals hinders high density.

Therefore, in view of the above points, the first aspect of the present invention
It is an object of the present invention to provide a recording method for a thermal line printer capable of relaxing a stick of thermal paper without increasing the size of the apparatus.

A second object of the present invention is to provide a recording method for a thermal line printer which can contribute to miniaturization.

A third object of the present invention is to provide a recording method for a thermal line printer which can extend the life of the battery in the thermal line printer driven by a battery.

[0022]

In order to achieve such an object, the first aspect of the present invention performs thermal recording by a thermal line head having a plurality of heating elements arranged in a line direction orthogonal to the paper feeding direction. The recording method of the thermal line printer is characterized in that the paper is fed by a minute amount which does not exceed the size of the heating element during the recording of one line.

A second aspect of the present invention is a recording method for a thermal line printer which performs thermal recording by a thermal line head having a plurality of heating elements arranged in a line direction orthogonal to the paper feeding direction, in which the heating elements to be simultaneously heated. The first print data for one line is divided so that the number is constant and dummy data for blank printing is added to the divided partial print data to create the second print data for one line. , Partial driving is performed by simultaneously driving the plurality of heating elements with the created second printing data, and the partial printing is performed in time series for each partial printing data obtained by dividing the first printing data. It is characterized by executing.

A third aspect of the invention is a recording method for a thermal line printer in which thermal recording is performed by a thermal line head having a plurality of heating elements arranged in a line direction orthogonal to the paper feeding direction, and a battery is used as a power source. Voltage is measured, the number of simultaneously driving the heating elements is variably set according to the magnitude of the measured voltage, and the plurality of heating elements are time-divisionally driven in the set number unit. Is characterized by.

[0025]

According to the first aspect of the present invention, the minute amount of paper is fed in the middle of one-line printing to shorten the time from the end of heating to the start of paper feeding as compared with the prior art, thereby reducing sticking of the thermal paper.

According to the second aspect of the invention, when one line is printed in time division by partial data, the heating elements are simultaneously driven by the print data obtained by adding blank dummy data to the partial data. Only one line is required.

In the third aspect of the invention, as the battery voltage decreases, the number of heating elements driven simultaneously is reduced, so that the instantaneous power consumption also decreases and the battery life becomes longer than before.

[0028]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 shows the external appearance of a portable computer device to which the present invention is applied. In FIG. 2, 1 is a main body, 2 is a thermal line printer for printing information processed by the main body 1, 3 is an input key for inputting data to the main body 1, 4
Is a liquid crystal display device for displaying information.

FIG. 3 shows the external appearance of the main body 1 of FIG. 1 as seen from the back side. In FIG. 3, 5 is a rechargeable battery for driving the main body 1. The battery 5 is composed of five NiCd batteries having an open voltage of 1.2V connected in series, and has a nominal voltage of 6V.
The discharge end voltage is 4.8V.

(Basic Structure of Thermal Line Printer) FIG. 4 shows the basic structure of the thermal line printer 2 shown in FIG.

In FIG. 4, reference numeral 31 is a thermal line head unit, and 32 is a cable. Reference numeral 33 is a head mounting plate, 34 is a mounting plate shaft, and 35 is a spring. 36 is a platen roller, 37 is a stepping motor, and 38 is a gear.

The thermal line head unit 31 is fixed to the head mounting plate 33, and the heating element of the thermal line head unit 31 has 0.12 dots per dot.
The size is 5 mm square, 512 dots are arranged in one row, and face the platen roller 36. The mounting plate shaft 34 is combined with the head mounting plate 33, both ends of which are supported by the printer unit main body (not shown), and the head mounting plate 33 can rotate about the shaft 34 as a fulcrum.

The upper end of the spring 35 is attached to the printer unit main body, and the lower end is attached to the head mounting plate 33. The head 31 is attached to the platen roller 36.
Is in close contact with. Both ends of the platen roller 36 are supported by the printer unit main body so as to rotate about the shaft, and one end of the platen roller 36 is driven by a stepping motor 37 via a gear 38.

A printing method in the thermal line printer thus constructed will be described below.

A thermal paper is inserted between the head 31 and the platen roller 36, and the print data (bit state of "1", "0") is sent to the thermal line head unit 31 from a main body control unit (not shown) by a method described later. ) Is sent, a heat signal is sent to the heating element to which the print data of the bit “1” has been input among the 512 heating elements, so that the heating element is heated.

On the surface of the thermal paper facing the head, the portion in contact with the heated heating element is discolored by substantially the same area as the heating element. After that, the platen roller 36 is driven by the stepping motor 37 according to an instruction from the main body control unit.
Is driven to feed the paper by the frictional force between the platen roller 36 and the thermal paper. The feed amount is 0.063 mm which is half the length of one side of the heating element when the stepping motor 37 is moved one step.

(Description of Control System of Portable Computer Device) FIG. 5 shows a circuit configuration of a control system of the thermal line printer having the above-mentioned configuration.

In FIG. 5, the voltage of the battery 5 is A / D.
A / D converted by the (analog / digital) converter 42,
A digital value indicating the voltage level is input to the I / O (input / output) port of the CPU (Central Processing Unit) 41. Since this A / D conversion is continuously performed at a constant cycle, the CPU
41 can always know the latest battery voltage.

Reference numeral 44 is a ROM (read only memory) in which programs and character fonts exist, and 45 is a RAM (random access memory) for expanding the character fonts. Both are connected to the CPU 41 by an address bus and a data bus. Reference numeral 54 is a stepping motor unit for feeding the paper, which is controlled by two excitation signals 56 and a hold signal 55 from the CPU 41.

A thermal line head unit 50 has the following components. That is, a 512-bit thermal line head 47 composed of 512 heating elements.
The 512-bit latch register 48 for temporarily storing print data currently being heated corresponding to 1 dot = 1 bit, and the 512-bit shift register 49 for temporarily storing print data for the next heat are the thermal line heads. Included in unit 50.

From CPU 41 to thermal head unit 5
0 is a print data transmission signal 51, and a latch signal 5 is for controlling data transfer from the shift register to the latch register.
2. The strobe signal 53 for controlling the heating of the heating element by the latch data is sent, and the CPU 41 controls the thermal head unit 50. The strobe signal 53 is connected to the gates of all 64 × 8 blocks (512) as shown in FIG. 6, and the heat execution of all 512 heating elements can be controlled by one control signal. it can.

(Control of Thermal Printer) Next, the control operation of the thermal line printer will be described with reference to FIG. In addition, in the numerical values used in the following description, the subscript h
Indicates hexadecimal display, subscript b indicates binary display,
No subscript indicates decimal notation.

The control procedure of FIG. 1 shows the control processing executed by the CPU 41, and this control procedure shows the control processing executed by the CPU 41, which is described in a program language executable by the CPU 41. At the time of printing, the CPU 41 reads this control procedure from the ROM 44 and executes the calculation.

When the CPU 41 receives the data to be printed, it uses the character fonts stored in the ROM 44 to develop a character font for one line on the RAM 45 as a bit image (S-1).

For example, in a thermal line printer using a 512-dot line head as in this embodiment, as shown in FIG.
When developing the 8 × 16 dot font shown in, the maximum 64 characters (3Fh) can be developed in the line direction. In the expansion example of FIG. 7, 49 characters (30h-0h
+1) It is deployed. RA for 1-dot row printing
010000h is the start pointer indicating the first address on M45, 010030h is the end pointer indicating the final expanded character (S-2), and the dot row number is 1
6 is set in the internal memory of the CPU 41 (S-3).

Next, the CPU 41 turns on the hold signal 55 and switches the excitation signal 56 to rotate the stepping motor 54 one step. This driving force is transmitted to the above-described paper feeding system and the stepping motor 54
The paper is fed by an amount corresponding to one step (S-
4). In this embodiment, half of the length of one side of the heating element is 1
The paper feed amount per step is configured.

Next, details of the 1-dot row printing of S-5 will be described with reference to FIGS. 8 and 9.

Since there is a time lag between the one-step paper feed control by the CPU 41 and the actual movement of the paper, and the surface of the paper vibrates for a while after the movement, the printing is waited for a fixed time managed by the timer 46. There must be.
Therefore, the motor hold signal 55 is turned off after the timer 46 measures the fixed time (S-10).

Generally, the hold signal of the step motor is always turned on during the operation of the motor, but in this embodiment, in order to suppress the power consumption as much as possible due to the nature of the portable computer, as described above, within the minute time of 1 dot printing. Even if it is (5 msec to 10 msec), it is devised to turn it off when unnecessary.

As an initial process for printing one dot row (line), the CPU 41 performs the following process (S11).

A) An initial value is set to the number of simultaneous heats described later.

B) Reset the byte counter that counts the bytes that have been printed.

C) Set the start pointer value to the get pointer.

Next, R of the value indicated by the get pointer
From the address on AM45, 1 byte of print data is C
It is read by the PU 41 (S12).

(Data Transfer Processing for Simultaneous Heating) In a portable computer, it is sometimes difficult to heat all the heating elements at the same time due to the limited battery capacity. In this case R
The print data (the first print data of the second invention) of one dot row (line) on the AM45 is divided into partial data which becomes the number of simultaneous heat dots (for example, 20 dots in the initial), and divided into several times. To print in time series.

For this purpose, first, the number of bits “1” (that is, the number of heat dots) in the 1-byte data read from the RAM 45 is calculated by using a look-up table preset in the ROM 44.

This lookup table is Ooh to FF
Bit “1” corresponding to each byte data (input value) of h
Is a data string of 256 in which the number (output value) of

The CPU 41 subtracts the calculated number of heat dots from the number of simultaneous heat dots (S13). When the subtraction result is larger than "0", that is, when it is determined that the read 1-byte data can be heated, the CPU 41 transfers the 1-byte data from the serial port to the 512-bit shift register 49 (S-14, S-15).

The number of simultaneous heat dots in the initials is determined by a method described later based on the A / D converted value of the battery voltage (timed voltage of the third invention).

In the example of FIG. 7, when the get pointer is 010000h by the processing of S-13 to S15, the 1-byte data of the address indicated by this pointer is 11000110b in binary notation. Since there are four "1" in this data, the number of remaining simultaneous heat dots is 16 (20-4
= 16). That is, it is determined that this 1-byte data can be heated.

Therefore, since the CPU 41 processes the next 1-byte data, the CPU 41 advances the get pointer and the byte counter (S-16).

In the expansion example of FIG. 7, get pointer = 01
Since 0001h and end pointer = 010030h, the CPU 41 confirms that reading of all print data is not completed and printing of 1/2 line is not completed (negative determination in S-17, S- 18), the procedure is returned to S-12, and the above-described processing for transferring the next 1-byte print data to the 512-bit shift register 49 is executed.

When the number of remaining simultaneous heat dots becomes less than "0" by repeating the loop process between S-12 and S-18, that is, the partial print data is stored in the shift register by the set number of heat dots. If it is done (S-14
A), a part of the 1-byte data (original data) currently being processed is masked from the LSB direction by the 1-byte data for masking so that the number of simultaneous heat dots becomes the set number (“20” at initial). (S-20),
The 1-byte data after the mask processing is transmitted to the shift register (S-21).

As described above, in the present embodiment, one strobe signal 53 controls all 512 heating elements, so that 512 dots are set so that the heating elements corresponding to the unprocessed byte data do not generate heat. Unseen bytes (64 bytes-byte counter) Space data (00h) (second
The dummy data of the invention) is transmitted to the shift register (S-22).

Wait for the end of the previous heat (S-
23), the CPU 41 sends a latch pulse to the latch register 48 of the recording head. As a result, the 512-bit print data previously stored in the shift register 49 by the above method is transferred in parallel to the latch register 48, and the shift register becomes ready to receive the 512-bit print data for the next heat.

After that, when the CPU 41 turns on the strobe signal 53, 512 set in the latch register is set.
The heating of the heating element corresponding to the bit for which "1" is set in the print data of the bit is started (S-2
4).

The strobe signal 53 is kept on by the timer 56 for a certain period of time (for about 0.8 to 0.9 msec until the heat generating element becomes hot and the heat-sensitive paper develops color), and then is turned off.

When the heat is started, the CPU 41 starts data transfer to the shift register 49 for the next heat. First, the space data (00h) for the processed byte counter is transmitted (S-25). Then, the original data of S-20 was masked with the data obtained by inverting "0" and "1" of the 1-byte data for mask used in the processing of S-20, so that the data could not be transferred in S-20. The 1-byte data corresponding to the bit is generated (S-26), and the initial value is set to the simultaneous heat dot number which is "0" (S-27).
Branch to the routine.

As described above, in the present embodiment, A. 1 byte of data is transferred to the shift register until the number of simultaneous heat dots becomes 0 (processing of S-12 to S18). B, unprocessed byte space data in 64 bytes is transferred to the shift register (S-14 to S-14). Processing of S22) C. Heat (processing of S-23, S-24) D. The space data for the processed bytes is transferred to the shift register (processing of S-25 to S27). One dot line is printed by repeating the above sequence A to D. That is, 64 bytes (512 bits) of data is always transferred before one heat.

(Control for Stick of Thermal Printer) The stick here means that the chemical applied to the surface of the thermal paper discolors and solidifies when cooled, so that the force for adhering the head to the paper is This is a phenomenon that occurs and becomes a resistance to the paper feeding force. This is a phenomenon that hinders smooth paper feeding and may cause uneven printing.

Next, the control of the stick countermeasure will be described.

When the sequence of A to D is repeated and the byte counter reaches "32" (S-19 affirmative determination in FIG. 8), that is, the processing up to 31 bytes corresponding to half 256 dots of 512 dots is performed. If done, above B
32 bytes of space data transmission (S-28 in FIG. 9), waiting for the end of the previous heat (S-29),
After the heat (S-30), one-step paper feed is performed (S-31).

In this embodiment, one step = 0.5 dots is used, and the first half 25 is set by the paper feeding.
The difference between the 6 dots and the 256 dots in the latter half is designed to be as inconspicuous as possible. After that, a flag indicating execution of intermediate paper feeding is set (S-32), an initial value is set to the number of simultaneous heat dots (S-33), and control before transition, that is, S-12 of FIG. Branch (S-3
4) Then, the above sequence A to D is repeated again.

When the one byte transmission of the character "I" (S-15 in FIG. 8) is completed and the get pointer / byte counter is advanced (S-16) in the expanded example of FIG. 7, the get pointer = 0.
It becomes 10031h. At this point, the get pointer> the end pointer (affirmative determination in S-17), and the CPU 41 determines that the characters have not been expanded thereafter, and the final heat processing A in one dot row (S-35 in FIG. 9). ).

The CPU 41 performs (6
4-byte counter) Space data of bytes is transmitted (S-35 in FIG. 9) and waits for the end of the previous heat (S-
36, execute the final heat with 1 dot row (S-3
7). In the printing of the character font expansion example of FIG. 7, as described above, the one-step paper feed is already executed at the intermediate point of the one-dot row, and the intermediate paper feed flag is set. Therefore, the flag is cleared (S-41), and the one-dot row printing subroutine is completed (S-42).

On the other hand, for example, when only 5 characters are font-developed, the paper feeding at the intermediate position is not executed, and the process branches to the final heat processing in this 1-dot row. Therefore, waiting for the end of the final heat (S-39), one-step paper feed is executed (S-40). After this, the 1-dot row printing subroutine is terminated, and the execution procedure is returned to S6 in FIG.

In S-5 of FIG. 1, when the above-described 1-dot row printing is completed, the CPU 41 advances the start pointer / end pointer by 64 and decreases the number of dot rows by -1 to prepare for the next 1-dot row printing (S- 6, S-7).

In the expansion example of FIG. 7, start pointer = 0
10040h, end pointer = 010070h, and dot row number = 15.

If the number of dot rows is not "0" (negative determination in S-8), one-step paper feed is executed (S-4).
The 1-dot printing paper has been fed from the start of the previous 1-dot row printing (the 1-step paper feeding executed in the 1-dot row printing subroutine and the 1-step paper feeding of S-4).

Therefore, the CPU 41 again prints the one dot row, the start / end pointer + 64, and the dot row number−.
Repeat 1 and when the number of dot rows becomes 0, that is, R
When printing of the last 1-dot string of the font developed on the AM is completed, 1-character string printing is completed (S-8, S-
9).

(Method for determining the number of simultaneous heat dots) FIG.
Is a flow chart for determining the number of simultaneous heat dots by the arithmetic processing of the CPU 41.

First, heat dots are set to 64 dots (S91). Next, while the battery voltage taken in by the above method is 6 V or more in this embodiment, the printer prints at the currently set number of heat dots (S9).
2).

The battery of this embodiment is 7.2 when fully charged.
V, and the voltage decreases as power is consumed. In addition, the voltage increases or decreases according to the number of simultaneous heat dots. For example, if the battery voltage is 6 V when the number of simultaneous heat dots is 64 dots, the battery always shows a voltage of 6 V or more when the number of dots is 48 dots or less.

Next, if the current set number of heat dots is 24, which is the minimum, this procedure is terminated, and the number of heat dots is fixed at 24 dots (S93). 64 → 48 → 32 when the number of set heat dots is other than 24 dots
→ The currently set number of heat dots is changed to the next number of heat dots in the order of 24 dots (S94).

FIG. 11 shows a battery discharge curve when the number of simultaneous heat dots is changed by the method of FIG. When the printer that was initially printing with 64 simultaneous heat dots reaches the heat dot change voltage (6 V), 64 → 48 →
It shows how the battery voltage increases at the same time when the number of dots changes from 32 to 24 dots.

<Other Embodiments> (1) In the above-described embodiment, when printing 512 dots per line, at the position of 256 dots which is a half line, 1 dot is set as a minute amount which does not exceed the size of the heating element. Paper feed of half the length of. However, the timing of this paper feed is not limited to a certain position, and the last position of the data of "1" to which the heat signal is sent is detected from the data of 512 bits per line, and that position is, for example, 420 bits. In the case of eyes, the paper feeding is performed at the position of the 210th bit, which is half the position, so that the position where the paper feeding is performed is changed by detecting the last heat position for each line. It can be performed.

(2) Further, as described above, the stick generation is affected by the elapsed time from the end of heating, so that not only the paper feeding is detected by the position detection, but also a timer is added to the control unit of the above embodiment. However, it is possible to combine time-based control such that the timer is reset each time printing of one line is started and the paper is fed when 0.1 seconds has elapsed.

(3) In the above-described embodiment, the thermal line head is divided into dots in order from the right end to the left end in order of the number of dots to be printed, but the printing may be reversed or from the center. The present invention can be applied to the case where the right and left portions are alternately divided.

(4) Furthermore, by combining the head history control and the time-division line recording of the present invention, it is possible to realize fine control in 1-dot units without the concept of blocks divided by strobe signals.

[0091]

As described above, according to the first aspect of the present invention, the paper of the minute amount that does not adversely affect the printing quality is fed during the printing of one line so that the power source battery is not burdened. In addition, the time from the end of heating to the start of paper feeding can be shortened, and the stick can be reduced without impairing the direction for downsizing.

According to the second invention, the heating elements can be simultaneously driven by the second print data for one line in which blank dummy data is added to the partial print data. There is only one strobe signal line for instructing. As a result, it is possible to contribute to miniaturization of the thermal line head as compared with the conventional example which requires a plurality of strobe signal lines. In addition, there is an effect that the concept of the heating element block in the line head is eliminated, and the head can be driven regardless of the printing position in the 1-dot row. Further, the second invention also has the flexibility of the firmware that even if the total number of dots of one dot line is changed due to the change of the head or the like, the method of driving the head is hardly changed.

According to the third aspect of the invention, the number of simultaneously driven heating elements is variable according to the voltage of the battery as the power source.
It is possible to prevent sudden consumption of the battery.

[Brief description of drawings]

FIG. 1 is a flowchart showing a recording order according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an appearance of a portable computer device to which the present invention is applied.

FIG. 3 is a perspective view of the main body 1 of FIG. 2 as viewed from the back side.

FIG. 4 is a perspective view showing the basic structure of the printer 2 shown in FIG.

FIG. 5 is a block diagram showing a circuit configuration of the present embodiment.

FIG. 6 is a block diagram showing a configuration of the thermal line head of FIG.

FIG. 7 is an explanatory diagram showing how fonts of this embodiment are expanded.

8 is a flowchart showing details of 1-dot row printing (S-5) in FIG.

9 is a flowchart showing details of 1-dot row printing (S-5) in FIG.

FIG. 10 is a flowchart showing a procedure for determining the number of simultaneous heat dots in this embodiment.

FIG. 11 is a characteristic diagram showing a battery discharge curve when the number of simultaneous heat dots in this example is changed.

FIG. 12 is a block diagram showing a circuit configuration of a conventional thermal line head.

FIG. 13 is a block diagram showing a circuit configuration of a conventional thermal line head.

FIG. 14 is a timing chart showing a recording operation timing of a conventional example.

[Explanation of symbols]

 1 Portable Computer Main Body 2 Thermal Line Printer Main Body 3 Input Key 4 Liquid Crystal Display 5 Rechargeable Battery 31 Thermal Line Head Unit 32 Cable 33 Head Mounting Plate 34 Mounting Plate Shaft 35 Spring 36 Platen Roller 37 Stepping Motor 38 Gear 41 CPU 42 A / D converter 44 ROM 45 RAM 46 timer 47 512 dot line head 48 512 bit latch register 49 512 bit shift register 50 thermal line head unit 51 print data transmission signal line 52 latch signal line 53 strobe signal line 54 stepping motor unit 55 hold signal Line 56 Excitation signal line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 2/325 B41J 3/20 114 F 8907-2C 117 A

Claims (3)

[Claims] 1. A recording method of a thermal line printer for performing thermal recording by a thermal line head having a plurality of heating elements arranged in a line direction orthogonal to a paper feeding direction, wherein the size of the heating element is in the middle of recording one line. A recording method for a thermal line printer, characterized in that the paper is fed by a minute amount that does not exceed the limit. 2. In a recording method of a thermal line printer for performing thermal recording by a thermal line head having a plurality of heating elements arranged in a line direction orthogonal to a paper feeding direction, a constant number of the heating elements to be simultaneously heated. So that the first print data for one line is divided, dummy data for blank printing is added to the divided partial print data, and the second print data for one line is created. The partial printing is performed by simultaneously driving the plurality of heating elements with the second print data, and the partial printing is performed in time series for each partial print data obtained by dividing the first print data. Characteristic thermal line printer recording method. 3. A recording method of a thermal line printer in which thermal recording is performed by a thermal line head having a plurality of heating elements arranged in a line direction orthogonal to the paper feeding direction and a battery is used as a power source, in which a voltage of the battery is measured. However, the number of simultaneously driving the heating elements is variably set according to the magnitude of the measured voltage, and the plurality of heating elements are time-divisionally driven in the set number unit. Recording method of thermal line printer.