JPH1153071A - Portable information equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the load on a power source battery and to prolong an operable time by varying the maximum number of simultaneously heated dots to a number matching the rest capacity of the power source battery when the battery rest of the power source battery decreases and its voltage drops. SOLUTION: For printing, the heating dots of a thermal head 5 are are heated and the power source voltage 18 has a voltage drop owing to a large current at this time. For the purpose, the voltage value of the power source battery 18 is converted from analog to digital by an analog-to-digital(A/D) conversion part 17 and compared by a central processing unit(CPU) 8 with the discharge characteristic curve that the power source battery uniquely has to specify the battery rest. The output voltage of the power source battery drops owing to continuous printing, but when this reaches its threshold value, the CPU 8 commands a decrease in the maximum number of simultaneously heated dots to carry on the printing process. Consequently, the output voltage rises. In this state, the printing is further carried on and when the voltage approximates the threshold value again, the maximum number of simultaneously heated dots is further decreased to perform the printing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a portable terminal device having a thermal line printer used as a data input device such as data for inventory control in a warehouse, and more particularly to a means for extending the operation time of the portable terminal device. is there.

[0002]

2. Description of the Related Art A thermal line printer is widely used as a conventional printer for portable information equipment. As an example, in a thermal line printer, a thermal head of one line is divided into six printing blocks, and 64 heating dots are arranged in one printing block. Server
The number of simultaneously heated dots is limited to a maximum of 64 in the multiple printer in order to prevent a large current from flowing through the circuit resistance in the thermal head and lowering the voltage of the head drive power supply. For this reason, when printing, if the number of simultaneously printed dots in one line exceeds 64 dots, a control unit that divides and prints each block is known.

[0003]

However, according to the above-mentioned prior art, the discharge characteristics are different depending on the performance of the battery used as the power source of the portable information equipment, but the heating dots provided in the print head are 64 dots. Even when printing is performed within the range, the voltage of the power supply battery drops. For this reason, the analog-to-digital conversion of the voltage value of the power supply battery by the A / D converter is performed by the C / C
When the capacity of the power supply battery reaches the same value as the set threshold value in order to limit the operation by reading the PU and limiting the capacity of the power supply battery, the battery information warning is issued by the portable information device. There is a problem that printing cannot be performed by the printer due to operation restrictions such as entering a mode in which the operation of the device main body is stopped or a system reset is applied.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional disadvantages, and has a power battery, an A / D converter for A / D converting a voltage value of the power battery, and an A / D converter. A CPU that inputs a voltage value that has been A / D-converted by the / D conversion, and simultaneously issues various commands to each component, and data from the CPU.
A thermal head in which a one-line thermal head is divided into a plurality of blocks by using a shift register and a latch register for inputting data, a platen and a pinch roller, and supplying thermal paper according to the rotation angle of a stepping motor. For printing characters and symbols defined by
In the multi-line printer, the voltage value of the power supply battery is A / D-converted by an A / D converter, and the A / D-converted voltage value is supplied to a shift register via a CPU, and supplied to the shift register. The portable information which outputs the voltage value to the latch register according to the command of the CPU, detects the remaining amount of the power supply battery, and outputs a strobe signal for printing the number of dots corresponding to the remaining amount of the battery. The equipment is the gist.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, a voltage value of a power supply battery provided in a portable information device is A / D-converted, and a CPU or a detector or a comparator provided in the portable information device is used. Monitor. The number of dots to be heated at the same time can be variably set in accordance with the remaining battery power. As an example, if the remaining amount of the power supply battery is 8.5 V to 7.0 V (a state in which the remaining amount is sufficient), the maximum number of simultaneous heating dots is 64 dots, and the maximum number of dots between 7.0 V to 6.0 V is maximum. The number of simultaneously heated dots is 32, and the maximum number of simultaneously heated dots is between 16 V and 5.0 V (in a state where the remaining amount is not so large). By controlling
The thermal line printer is controlled according to the remaining amount of the power supply battery to extend the operable time of the portable information device.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing the appearance of a thermal line printer according to the present invention, FIG. 2 is a block diagram according to the present invention, FIG. 3 is a diagram showing a variable maximum simultaneous heating dot for one-line printing, and FIG. It is a discharge characteristic diagram by the change of the consumption voltage at the time of changing.

First, FIG. 1 will be described. Reference numeral 1 denotes a thermal line printer, which is incorporated in a part of a housing of a portable information device (not shown). The thermal line printer 1 uses a platen 2 as a supporting portion to bring a head 3 and a thermal paper 4 into close contact with each other, and a horizontal line type thermal line head 5 disposed on the lower surface of the head 3 forms a dot pattern of one line. The heating (not shown) causes the thermal paper 4 to be colored and printed, and the pinch roller 7 is rotated by the stepping motor 6 to repeatedly feed the thermal paper 4 by one line. .

FIG. 2 is a block diagram showing a control method of a thermal printer in a portable information device. The thermal line printer 1 shown in this embodiment uses a thermal head 5 having a total number of dots of 384 dots, and is divided into six blocks of 0 to 5 as shown in FIG. Each block has 64 heating dots. Data to be printed on the thermal paper 4 defines one dot as one bit, and this print data is transferred from the CPU 8 mounted on the main body of the portable information device to the shift register 9 as serial data. The data is input to the shift register 9 as data for one line in synchronization with the output clock.

The print data input to the shift register 9 is recorded in the latch register 10 by a latch signal output from the CPU 8. The print data recorded in the latch register 10 is transmitted from the CPU 8 to the latch register 10 even if the contents stored in the shift register 9 change.
Is recorded in the shift register 9 as it is, unless the latch signal input to is turned ON. The print data recorded in the latch register 10 is CP
When any one of strobe signals 0 to 5 output from U8 is turned on, the strobe signal is output to physical blocks 0 to 5 corresponding to each strobe signal 0 to 5, and heating in each block is performed. The dots are heated according to the dot pattern of the print data.

If there are more than 64 heated dots in one line, they are divided and printed. The motor drive pulse 12 output from the CPU 8 is the motor driver 1
The motor driver 13 drives a stepping motor 14 for feeding the thermal paper 4. Reference numeral 15
Is a ROM in which a program for a portable information device is stored. The RAM 16 is used as a work area for programs recorded in the ROM 15 and a storage area for print data. A / D converter 1 converts the voltage value of power supply battery 18
The analog-to-digital conversion is always performed at 7, and the voltage value of the power supply battery 18 can be recognized by being input to the CPU 8.

Next, the actual operation will be described. When printing on the thermal paper 4, the heating dots of the thermal head 5 are heated as described above. At this time, since a large current is supplied from the power supply battery 18, a voltage drop occurs depending on the type of battery. The CPU 8 controls the A / D converter 17
The CPU 8 recognizes the voltage value of the power supply battery 18 that has been subjected to the D / D conversion, and compares the discharge characteristic curve inherent to the power supply battery with the above-mentioned voltage value. To identify. Next, description will be made with reference to FIG. When the maximum number of simultaneously heated dots is 64 (Fig. 3-
In (A), since the load on the power supply battery 18 is increased to simultaneously heat up to the maximum of 64 dots, a voltage drop occurs depending on the type of the power supply battery used. If the maximum number of simultaneously heated dots is set to 32 dots (FIG. 3-B), heating can be performed with half the voltage of 64 dots, so that power consumption is reduced and the voltage drop width of the power supply battery is reduced. I do. Similarly, if the maximum number of simultaneously heated dots is 16 dots, the power consumption is further reduced by half from 32 dots, and the width of the voltage drop is also reduced by half.

Next, the case where the maximum number of simultaneously heated dots is varied (for example, when 64 dots are changed to 32 dots) will be further described. As shown in FIG. 3, one block is divided into 1/2 to 1/4 and heated. If the maximum number of simultaneous heating dots is 32, one block of 64 dots is divided into two blocks of 32 dots each.
Considering that it is divided into two parts, 64 dots are divided into 32 dots and printed. As a printing method at this time, the data is transmitted from the CPU 8 to the shift register 9 by setting the first 32 dots to black (1) and the remaining 32 dots to white (0). The data transmitted to the register 9 is sent to the latch register 10 and stored by the latch signal from the CPU 8, and the first 32 dots are heated and printed by the strobe signal from the CPU 8. In the next head, for example, the first 32 dots are set to white (0), the latter 32 dots are set to black (1), and this data is transmitted from the CPU 8 to the shift register 9 to be shifted. Data is recorded from the register 9 to the latch register 10, and the data is recorded by a strobe signal from the CPU 8.
Prints by heating the latter 32 dots. Even if the maximum number of simultaneous heating dots is 16 dots,
It is possible to control the block of dots by 1/4.

FIG. 4 shows the output voltage of the power supply battery 18 when printing is performed by a thermal line printer using the above method. When the maximum number of simultaneously heated dots is continuously printed at 64 dots, the output voltage of the power supply battery 18 decreases as indicated by a solid line portion 19 in FIG. Set threshold value 22 (minimum voltage at which the thermal printer can operate)
When the output voltage 19 reaches the above, the maximum simultaneous heating dot number is switched from 64 dots to 32 dots in accordance with a command from the CPU 8, and printing processing is performed. 32 from this 64 dots
When switching to the dot, the output voltage of the power supply battery 18 rises as indicated by a broken line portion 20. When printing is further continued in this state, the voltage of the power supply battery 18 (broken line portion 20) approaches the threshold value 22 again. At this time, the printing process is performed by switching the maximum simultaneous heating dot number from 32 dots to 16 dots according to a command from the CPU 8. As a result, the load on the power supply battery 18 is reduced again.
As shown by 1, the voltage drop decreases, and the voltage value increases from around the threshold value 22.

[0014]

As described above, the present invention has the above-described structure, and when printing is performed using a thermal line printer provided in a portable information device, the remaining battery power of the power supply battery is reduced. When the amount decreases and the voltage decreases, the load on the power supply battery is reduced by changing the maximum number of simultaneous heating dots to the maximum number of simultaneous heating dots that matches the remaining capacity of the power supply battery. Extend the operating time of the main unit.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a thermal line printer.

FIG. 2 is a configuration block diagram

FIG. 3 is a variable diagram of a maximum simultaneous heating dot.

FIG. 4 is a discharge characteristic diagram due to a change in consumption voltage when a maximum simultaneous heating dot varies.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal line printer 2 Platen 3 Head 4 Thermal paper 5 Thermal line head 6 Stepping motor 7 Pinch roller 8 CPU 9 Shift register 10 Latch register 11 Head drive power supply 12 Motor drive pulse 13 Motor driver 14 Stepping motor 15 ROM 16 RAM 17 A / D converter 18 Power supply battery 19 Output voltage (at 64 dots) 20 Output voltage (at 32 dots) 21 Output voltage (at 16 dots)

Claims (1)

[Claims] 1. A power supply battery, and a voltage value of the power supply battery is A / A
A / D converter for D / D conversion, and A / D conversion
A CPU that inputs the / D-converted voltage value and simultaneously issues various commands to each component, a shift register and a latch register that input data from the CPU, a platen and a pinch roller, and uses a stepping motor. A thermal line printer that supplies thermal paper according to the rotation angle of the thermal printer and prints, on the thermal paper, characters and symbols determined by the thermal head in which one line of thermal head is divided into a plurality of blocks. A / D converting the voltage value of the power supply battery by an A / D converter, supplying the A / D-converted voltage value to a shift register via a CPU, and converting the voltage value supplied to the shift register to A strobe signal for outputting to the latch register according to the command of the CPU, detecting the remaining amount of the power supply battery, and printing the number of dots corresponding to the remaining amount of the battery. Portable information device and outputs.