JPH10289037A - Battery voltage monitoring device and wireless printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust detection voltage by calculating a correction value at the time of applying reference voltage and adding the correction value to measurement voltage. SOLUTION: CPU 6 starts a battery voltage correction program stored in F-ROM 7. A battery pack 1 is taken out and external reference voltage V is connected instead. External reference voltage V is divided into 1/2 by division resistances 2 and 3 and they become internal reference voltage. It is inputted to an A/D converter 5. A difference between external reference voltage V and measurement voltage is set to be the correction value and is stored in F-ROM 7. At a battery voltage detection mode, the battery voltage of the battery pack 1 is inputted and the correction value is added to measurement voltage at that time so as to make it to be detection voltage. The correction value is calculated and the correction value is added to measurement voltage. Thus, detection voltage can precisely be adjusted by absorbing the fluctuation of the respective parts of a device. Thus, detection voltage can highly precisely be adjusted by detecting a peripheral temperature and correcting fluctuation owing to the temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery voltage monitoring device for monitoring the voltage of a battery power supply used in a portable terminal, displaying a warning of a voltage drop or shutting down the power supply. The present invention relates to a wireless printer that is connected by optical communication and performs printing according to an instruction from a host terminal.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional battery voltage monitoring device divides the voltage of a battery pack 101 into divided resistors 102, 1 and 2.
03, the A / D converter 6 compares the input voltage with the A / D reference voltage 105. When the input voltage falls below a certain level, the CPU 107
By blinking the display of 0 or turning on the LED of a different color, a warning of a voltage drop is displayed. The operation program of the system is stored in the ROM 108,
109 writes and reads data necessary for the operation. Adjustment of the detection voltage is performed by the input-side variable resistor 104 in a state where the value of the input voltage is set to the value of the detection voltage.

On the other hand, since a conventional wireless printer uses a battery as a power source, the problem is how to make the battery last longer. Since the wireless printer prints data sent from the host terminal by wireless or optical communication, the data is temporarily stored in RAM and then printed. The capacity will be consumed.

[0004]

In the above-described conventional battery voltage monitoring device, the adjustment of the detection voltage requires an adjustment on the order of 10 mV, and the adjustment by the variable resistor has a narrow range. However, there is a problem that the adjustment is difficult because the adjustment value does not fall within the adjustment range or the set value of the variable resistor is shifted due to aging. Therefore, an object of the present invention is to provide a battery voltage monitoring device that can easily adjust a detection voltage.

Further, in the above-mentioned conventional wireless printer, since all data is transmitted from a host terminal, when the amount of data transmission is large, not only the printing time but also the communication time becomes longer, and the battery becomes longer. It will consume capacity. Therefore, an object of the present invention is to provide a wireless printer that can suppress consumption of battery capacity.

[0006]

The battery voltage monitoring device according to the present invention is arranged such that the detection voltage is adjusted not by a variable resistor but by software, and the correction value at the time of applying a reference voltage is adjusted. By calculating and adding the correction value to the measured voltage, it is possible to perform accurate adjustment of the detected voltage, which absorbs variations in each part of the device. Further, by detecting the ambient temperature and correcting the fluctuation due to the temperature, the detection voltage can be adjusted with higher accuracy.

According to the wireless printer of the present invention, data having a fixed format such as a form is not transmitted from the host terminal to the wireless printer, but is stored in the wireless printer itself, and only the changed data is transmitted from the host terminal to the wireless printer. However, by combining the data with the fixed format data on the wireless printer side, the transmission time is greatly reduced, and the consumption of battery capacity is suppressed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to a first aspect of the present invention is directed to a battery voltage monitoring device that detects a decrease in battery voltage and performs a predetermined warning operation. Then, a measurement voltage is obtained from the A / D conversion value, the A / D reference voltage value, and the A / D resolution at that time, and the difference between the external reference voltage and the measurement voltage is stored as a correction value in a storage unit. In the voltage detection mode, the battery voltage monitoring device is provided with control means for inputting a battery voltage and adding the correction value to the measured voltage at that time to obtain a detection voltage, and has an operation of accurately adjusting the detection voltage. .

According to a second aspect of the present invention, there is provided the battery voltage monitoring apparatus according to the first aspect, further comprising a temperature detecting means, wherein the detected voltage is corrected based on the detected temperature. This has the effect of performing the adjustment accurately.

According to a third aspect of the present invention, there is provided a wireless printer which is connected to a host terminal by wireless communication or optical communication and performs printing in accordance with an instruction from the host terminal, and exchanges data with the host terminal. Wireless communication means for performing, a storage means for registering a fixed format in advance, a control means for creating print data by incorporating change data in the fixed format, and a printing means for printing the created print data Wireless printer, which has the effect of reducing data transmission time and suppressing battery capacity consumption.

According to a fourth aspect of the present invention, there is provided the wireless printer according to the third aspect, wherein the control means has a function of combining a plurality of fixed formats into one fixed format. To reduce the battery capacity consumption.

(Embodiment 1) FIG. 1 shows a configuration of a battery voltage monitoring apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a battery pack, which uses a lithium ion battery. Reference numerals 2 and 3 denote divided resistors, and a connection point between the two is connected to one input side of the A / D converter 5. Reference numeral 4 denotes an A / D reference voltage connected to the other input side of the A / D converter 5. The A / D converter 5
The input voltage is compared with the A / D reference voltage 4 and the result is output as a digital value. Reference numeral 6 denotes a CPU, which controls the entire apparatus and determines an A / D converted detection voltage. 7 is an F-ROM (flash ROM),
The correction values calculated by the correction program, the system program, and the correction program are stored. Reference numeral 8 denotes a RAM for writing and reading data necessary for the operation of the apparatus. Reference numeral 9 denotes a resistor that forms a dividing resistor together with the thermistor 10, and a connection point between the two is connected to the input side of the A / D converter 11. The thermistor 10 is a temperature sensor that detects the temperature around the device. A / D converter 1
A / D reference voltage 4 is connected to the other input side of 1,
The output side is connected to CPU6. Reference numeral 12 denotes an LED, which is controlled by the CPU 6 to change the lighting state when the battery voltage falls below a certain level, or to switch the LED of another color.
Lights up.

Next, the operation of adjusting the detection voltage in the present embodiment will be described. The CPU 6 activates a battery voltage correction program stored in the F-ROM 7. First, the battery pack 1 is removed, and an external reference voltage V is connected instead. The external reference voltage V is halved by the split resistors 2 and 3.
And becomes an internal reference voltage, which is input to the A / D converter 5. The relationship (theoretical value) between the external reference voltage V and the A / D conversion value N is as follows. V = N × (A / D reference voltage × 2 × 1000) ÷ A / D resolution (1) Here, the number 2 in parentheses indicates that the input voltage was divided into に よ り by the dividing resistor. Number 10 to restore
00 is for converting to mA.

On the other hand, the measured voltage Vbat when the battery pack 1 is actually mounted, not the external reference power supply V, is used to correct the fluctuation due to variations in the split resistors 2, 3 and the A / D reference voltage 4. Expression (2) obtained by adding the correction value α to Expression (1)
become that way. Vbat = N × (A / D reference voltage × 2 × 1000) ÷ A / D resolution + correction value α (2)

Next, an A / D conversion value N when a reference voltage of 7.2 V is applied from the outside is obtained. When the acquired A / D conversion value N is 750, the measured voltage Vbat is obtained from the equation (2).
Is calculated. Here, the A / D reference voltage is 5 V, and the A / D resolution is 1024 steps when the A / D converter 5 has 10 bits. Measurement voltage Vbat = 750 × (5 × 2 × 1000) ÷ 1024 + α = 7324 + α (mV)

The new correction value αi is given by the following equation (3) in which the previous correction value α is added to the difference between the reference voltage and the measured voltage. In the case of the first correction, there is no effect because the correction value is zero, but in the case of the second and subsequent corrections, since the effect of the previous correction value remains, the previous correction value α is used to cancel the effect. Is added. New correction value αi = reference voltage−measurement voltage + α (3) Since the measurement voltage is 7324 + α (mV), the new correction value αi is as follows. The new correction value αi = 7200− (7324 + α) + α = −124 This new correction value αi = −124 is written in the flash ROM 7 and the battery voltage correction program is terminated.

Next, the operation shifts to a normal battery voltage detecting operation. Remove the external reference voltage and connect the battery pack 1. The voltage of the battery pack 1 is input to the A / D converter 5 to obtain an A / D conversion value N. For example, when the voltage of the battery pack 1 is 7.2
If it is V, the A / D conversion value is 750, and the measured voltage Vbat at this time is as follows from equation (2). Measurement voltage Vbat = 750 × (5 × 2 × 1000) ÷ 1024-124 = 7200 (mV) Thus, it can be seen that the correct measurement voltage 7200 mV was obtained by adding the new correction value -124.

After the detection voltage is corrected, the voltage of the battery pack 1 is periodically measured, and the measured value is set in advance to F-R
The detected voltage is compared with a detected voltage value table stored in OM7.
6 changes LED12 to blinking display, LE of different color
Lights D to warn the user of the need to charge the battery,
Perform power-off processing to prevent malfunction.

In a lithium ion battery, since the capacity and the voltage of the battery are substantially proportional to each other, the remaining amount of the battery can be detected by measuring the battery voltage. However, the battery voltage greatly changes depending on the temperature. It also has characteristics. For this reason, conventionally, the detection value is corrected in three stages of 20 degrees or more, 20 degrees to 10 degrees, and 10 degrees or less, but in the present embodiment, the ambient temperature is detected by the thermistor 10. , Its value and A / D reference voltage 4
By comparing the detected voltage value table with the / D converter 11 and inputting it to the CPU 6 and switching the above-described detected voltage value table, it is possible to perform more accurate correction of the battery voltage detected value.

As described above, according to the first embodiment, in the reference voltage setting mode, an external reference voltage is input, and the A / D conversion value, the A / D reference voltage value, and the A / D resolution at that time are used. In addition to obtaining the measurement voltage, the difference between the external reference voltage and the measurement voltage is stored in the F-ROM as a correction value. In the battery voltage detection mode, the battery voltage of the battery pack is input, and the correction value is applied to the measurement voltage at that time. In addition, since the detection voltage is used, the detection voltage can be adjusted accurately and accurately.

(Embodiment 2) FIG. 2 shows a configuration of a wireless printer according to Embodiment 2 of the present invention. In FIG. 2, reference numeral 21 denotes an IrDA module for transmitting and receiving data to and from a host terminal by infrared rays;
Is a communication control unit for controlling communication by the IrDA module 21, and 23 is a CPU for controlling the entire apparatus. Reference numeral 24 denotes a serial connector that transmits and receives data to and from another host terminal via a cable in accordance with RS-232C. 25 is a RAM for writing and reading data required for operation, 26 is an F-ROM for registering a communication control program and fixed format data, 27 is a font ROM for storing font data, and 28 is an LED indicating the operation state of the device. Display unit 29, a battery power supply using a lithium ion battery, 30 a printer unit for printing, a control unit for controlling a page buffer RAM and a printer driver for developing a print pattern, and a printer for actual printing It consists of a head and the like.

The data sent from the host terminal by infrared rays is received by the IrDA module 21, decoded by the communication control unit 22, and decoded by the buffer RAM of the printer unit 30.
Is stored in the printer unit 30 and is output from the printer unit 30. In the case of data having a fixed format such as a form, since only the data of the change unit is sent from the host terminal, the CPU 23 temporarily stores the data in the RAM.
25, read out the required fixed format from the F-ROM 26, combine it with the changed data, and pass it to the printer unit 30. The printer unit 30 performs printing based on the synthesized data.

The operation of registering a fixed format will be described below. There are four types of fixed format registration: character registration, ruled line registration, barcode registration, and bit image registration. These four types of fixed formats can be printed as a single form by registering them under the same number, creating a bit pattern of one form, and transmitting the same as a bit image to a printer driver. Also, these four types of fixed formats can be registered independently, and some fixed formats can be arbitrarily combined and printed as one sheet. The form to be printed is preliminarily designed with a stamp surface, and it is determined in advance what position should be printed and what position the character should be variable data. The format registration command (character, kanji) registers data such as X and Y data of a print location, print data length, print font, and print direction.

FIG. 3 shows an example of bit distribution in registration of a fixed format. Registered by the value of n /
The functions of designation / bit image designation are classified, and various page mode settings are made. b0 to b4 are format registration numbers (0 ≦ n ≦ 31, the number of registrations changes depending on the setting contents). When kanji data, ruled lines, and bit images are printed in an overlapping manner, the same registration number is used. . Using the bits b5 to b7, various settings such as version setting registration, character, kanji code registration, ruled line registration, barcode registration, bit image registration, character, kanji code designation, format designation, and barcode designation are performed. . Also, when performing paper setting registration for setting the size of one page operating in the page mode, b
The horizontal print setting area X and the vertical print area setting Y are performed by setting 5 to b7 to zero. FIG. 4 shows an example of character and kanji code registration, and FIG. 5 shows an example of a print font setting Zm therein.

As described above, according to the second embodiment,
In a wireless printer that is connected to the host terminal by wireless communication or optical communication and performs printing in accordance with an instruction from the host terminal, an IrDA module 21 and a communication control unit 22 that exchange data with the host terminal and a fixed format are previously stored. Since there is provided an F-ROM 26 to be registered, a CPU 23 for creating print data by incorporating changed data into a fixed format, and a print unit 30 for printing the created print data, data having a fixed format is used. Can greatly reduce the data transmission time from the host terminal, and can suppress the consumption of the battery capacity of the battery power supply 29 in the wireless printer.

[0026]

As is clear from the above embodiment, the battery voltage monitoring device of the present invention calculates a correction value when a reference voltage is applied and adds the correction value to the measured voltage, thereby obtaining a variation in each part of the device. It is possible to perform accurate adjustment of the detection voltage that absorbs the above. Further, by detecting the ambient temperature and correcting the fluctuation due to the temperature, the detection voltage can be adjusted with higher accuracy.

As is clear from the above embodiment, the wireless printer of the present invention has data in a fixed format such as a form in the wireless printer itself, transmits only the changed data from the host terminal, and transmits the changed data to the wireless printer. Since the data is synthesized with the fixed format data, the transmission time can be greatly reduced, and the consumption of the battery capacity can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a configuration of a battery voltage monitoring device according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram illustrating a configuration of a wireless printer according to a second embodiment of the present invention.

FIG. 3 is a bit configuration diagram for describing a fixed format registration operation according to the second embodiment of the present invention.

FIG. 4 is a data structure diagram for describing a character / kanji code registration operation in the second embodiment of the present invention.

FIG. 5 is a diagram illustrating a bit configuration for setting a print font in a character / kanji registration operation.

FIG. 6 is a schematic block diagram showing a configuration of a conventional battery voltage monitoring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery pack 2, 3 divided resistor 4 A / D reference voltage 5 A / D converter 6 CPU 7 F-ROM 8 RAM 9 Divided resistor 10 Thermistor 11 A / D converter 12 LED 21 IrDA module 22 Communication control unit 23 CPU 24 Serial Connector 25 RAM 26 F-ROM 27 Font ROM 28 Display 29 Battery Power 30 Printer

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masahiro Nakamura 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inside the corporation

Claims (4)

[Claims] In a reference voltage setting mode, an external reference voltage is inputted, an A / D conversion value at that time, and an A / D reference value are detected. The measured voltage is obtained from the voltage value and the A / D resolution, and the difference between the external reference voltage and the measured voltage is stored in a storage unit as a correction value. In the battery voltage detection mode, the battery voltage is inputted and the measurement at that time is performed. A battery voltage monitoring device comprising: a control unit that adds the correction value to a voltage to obtain a detection voltage. 2. The battery voltage monitoring device according to claim 1, further comprising a temperature detecting means, wherein the detected voltage is corrected based on the detected temperature. 3. A wireless printer which is connected to a host terminal by wireless communication or optical communication and performs printing in accordance with an instruction from the host terminal, wherein a wireless communication means for exchanging data with the host terminal and a fixed format are provided in advance. A wireless printer comprising: storage means for registering; control means for creating print data by incorporating changed data into the fixed format; and print means for printing the created print data. 4. The wireless printer according to claim 3, wherein the control means has a function of combining a plurality of fixed formats and combining them into one fixed format.