JPH03240181A - Information reader - Google Patents

Abstract

PURPOSE:To use an information read main body continuously by indicating that the voltage across an internal secondary battery drops below a reference value and cutting the electric power supply from the secondary power battery when the secondary battery voltage drops below the reference value, and then connecting the power cable of an external power source to the information read main body and supplying power. CONSTITUTION:When the voltage across the secondary battery 20 drops below the reference value during the use of the information read main body 1, a voltage monitor means 23 detects that to operate a voltage drop indicating means 25 and also turn off a switch means 26, thereby cutting off the power supply from the secondary battery 20. Then an operator after recognizing the operation of the voltage drop indicating means 25 connects the power cable 19 to the information read main body 1, and turns on the switch means 26 when a voltage monitor means 23 decides that an external source voltage is larger than the reference value, so that the information read main body 1 is powered on by the external power source 16. Consequently, even when the voltage across the secondary battery 20 drops below the reference value, the information read main body 1 can be used continuously.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an information reading device such as a cordless barcode reader. This invention relates to an information reading device that can be charged when the device is not in use.

(Prior Art) For example, in a hand-type barcode reader that optically reads a barcode pattern formed on a product, barcode readers are It has a cordless structure that can be separated from the bare register or personal computer. Along with this, the Barcode League has a built-in secondary battery that supplies power to its components, including a light source for illumination, a light receiving element for reading barcode patterns, and a transmission circuit that transmits the read barcode information to a register etc. Ru.

When the barcode league is made cordless in this way, it is desirable that the barcode league be able to be used stably for a long time and that it be lightweight.

By the way, it is conceivable to increase the capacity of the built-in secondary battery so that it can withstand long-term use of the barcode league.

However, when the capacity of the secondary battery is increased, the secondary battery becomes larger and heavier, and the barcode league body also becomes heavier.

Therefore, in order to make the secondary battery small and lightweight, and to be able to use it for a long time, a charging device is installed on a dedicated stand for barcode information, and when the barcode league is not in use,
A method is known in which a secondary battery is irregularly charged by a charging device by installing it on a dedicated installation stand.

However, with the conventional charging method as described above, the voltage of the secondary battery drops due to the use of the barcode league, and if the usage conditions are such that charging is not possible even though charging is required, the secondary battery cannot be charged. The capacitive force S may reach the discharge end voltage or lower.

In such a case, if the secondary battery capacity drops below the discharge end voltage while the barcode league is in use, the functions of the various circuits that make up the barcode league will deteriorate and errors will occur in the processing of barcode information. In addition to being unusable, there was a problem in that use of the barcode league had to be interrupted while the secondary battery was being charged to the upper limit voltage.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an information reading device that can be used continuously for 6 times when the voltage of the secondary battery decreases and becomes unusable.

(Means for Solving the Problems) The present invention provides an information reader that optically reads information attached to an object to be read and includes a processing unit that processes the read information and a secondary battery that supplies power to the processing unit. In an information reading device having a main body and a charging circuit for charging the secondary battery when the information reading main body is not in use, when the voltage of the secondary battery is below a reference value, an external power source is connected to the information reading main body. a power supply cable separably connected to the information reading main body for supplying external power from the main unit; a voltage monitoring means for monitoring the voltage of the secondary battery and the external power supply voltage; When the voltage drop of the secondary battery is detected, the voltage drop notification means notifies that the voltage is below the reference value, and when the voltage monitoring means detects that the voltage of the secondary battery is below the reference value, It is equipped with a switch means that cuts off the power supply from the battery and turns it on when the voltage of the secondary battery and the external power supply voltage are higher than a reference value.

(Function) When the voltage of the secondary battery falls below the reference value while the information reading unit is in use, the voltage monitoring means detects this and operates the voltage drop alarm means, and turns off the switch means to switch off the secondary battery. Cut off the power supply from the battery.

After the operator recognizes the operation of the voltage drop alarm means, the power supply cable is connected to the information reading unit, and when the voltage monitoring means determines that the external power supply voltage is higher than the reference value, Turn on the means and operate the information reading main body with an external power source.

Therefore, even if the voltage of the secondary battery drops below the reference value, the information reading main body can be used continuously.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 shows an overall configuration diagram when the device of the present invention is applied to a barcode league.

In the same figure, ■ is a cordless separate barcode league corresponding to the information reading body, which includes an illumination light source 2 consisting of an infrared light emitting diode, a light source drive circuit 3, and a bar illuminated by the illumination light source 2. A light receiving element 5 such as a CCD that receives reflected light from the code label BL via a condensing lens 4, an amplifier circuit 6 that amplifies the analog signal output from the light receiving element 5, and an output signal of this amplifier circuit 6 as a reference. A waveform shaping circuit 7 that compares the voltage with the voltage and converts it into a binary signal depending on whether it is large or small, an arithmetic processing circuit 8 that converts the binary signal from the waveform shaping circuit 7 into barcode information, and this arithmetic processing circuit. A transmitting circuit 9 is provided for converting the output signal from 8 into an optical signal or the like and transmitting the converted signal to a computer or the like.

Reference numeral 10 denotes a power supply unit built into the barcode reader l, which connects a secondary battery for power storage and an external power source to a light source drive circuit 3, a light receiving element 5. A voltage monitoring circuit 23.Secondary is configured to supply power to the amplifier circuit 6, waveform shaping circuit 7, arithmetic processing circuit 8, and transmission circuit 9, respectively, and monitors the voltage of the secondary battery 20 and external power supply voltage, which will be described later. A charging input terminal 11a includes a display circuit 25 for notifying a battery voltage drop and a switch circuit 26 for turning on/off the supply of power, and further supplies charging power to the secondary battery 20.

11b and an external power input terminal 12.

Reference numeral 13 denotes a dedicated installation stand on which the barcode reader l is removably installed, and inside this dedicated installation stand 13, there is a charging power supply unit 14 consisting of a booster circuit that generates a DC voltage for charging, and a charging power supply unit 14 for charging. A charging circuit 15 charges the secondary battery 20 of the barcode reader power supply unit 10 to a predetermined voltage using the charging power supply unit 14, and the voltage of the charging power supply unit 14 is used to operate various circuits in the barcode reader l. An external power supply circuit 16 is provided for converting the voltage into the voltage required for this purpose.

The charging circuit 15 includes a charging output terminal 17a, which is connected to and separated from charging input terminals 11a and llb of one example of a barcode reader.
17b, and these output terminals 17a, 17b are provided in a recess 13a of the dedicated installation stand 13 for engagement with a barcode reader.

Further, the external power supply circuit 16 includes a power supply terminal 18, one end of a power supply cable 19 is connected to this power supply terminal 18, and the other end of the power supply cable 19 is connected to an external power input terminal 12 on the barcode reader l side. It is designed so that it can be separably connected to the

Next, a specific example of the configuration of the power supply section 10 will be explained with reference to FIG.

In FIG. 2, a charging input terminal 11a.

A secondary battery 20 such as a nickel-cadmium storage battery is connected in parallel between the terminals 11b and 11b. The positive electrode of the secondary battery 20 is connected to the output terminal 22a via the backflow prevention diode 21 and the line Ll, and the negative electrode of the secondary battery 20 is connected to the output terminal 22b via the line L2.

The output terminals 22a, 22b are connected to the light source drive circuit 3, amplifier circuit 5, etc. in the barcode reader 1. It is connected to the waveform shaping circuit 6, the arithmetic processing circuit 7, and the transmitting circuit 8.

External power input terminal 12 is connected to lines Ll and L2.

23 is a voltage monitoring circuit that monitors the terminal voltage v1 of the secondary battery 20 and the voltage V2 from the external power supply circuit 16 supplied to the external power input terminal 12, and is connected in series between lines LL and L2, Resistors R1 and R detect the terminal voltage V of 20 and the voltage v2 applied to the external power input terminal 12.
2, a resistor R3 and a Zener diode Z that are connected in series between lines LL and L2 and generate a reference voltage Vref.
D, and a comparator COM whose inverting input is the voltage divided by the resistors R1 and R2, and whose non-inverting input is the reference voltage Vref of the Zener diode ZD.

Comparator COM has voltage V or v2 as reference voltage V
When the voltage v1 is larger than the reference voltage Vref, an "L" output is sent out, and when the voltage v1 is smaller than the reference voltage Vref, an "H" output is sent out.

The monostable multi-bi break 24 is configured when the output signal SI of the voltage monitoring circuit 23, that is, the output of the comparator COM is "H".
, it outputs an output of "1" for a certain period of time from its rise, and a display circuit 25 is connected to the output terminal of this monostable multi-bi break 24 to notify of a voltage drop in the secondary battery 20. .

The display circuit 25 has a power terminal 25 connected to the line Ll.
Display element 25 such as an LED connected in series between d and ground
a, a protective resistor 25b, and a transistor 25c for lighting the display element, and the output signal S2 of the monostable multi-bibreak 24 is applied to the base of the transistor 25c.

26 is a switch circuit that controls on/off the voltage 1 or V2 supplied from the secondary battery 20 and the external power input terminal I2 to the output terminals 22a and 22b, and is a P-channel MO5I- connected in series to the line Ll. Ranjistor 26
a, a resistor 26b connected between the source and gate of this MOS transistor 26a, and MO3! -Ran resistor 26
A transistor 26c connected between the gate of a and the ground, and a NAND connected to the base of this transistor 26c.
The NAND gate 26d receives a signal obtained by inverting the output signal SI of the voltage monitoring circuit 23 and the output signal S of the monostable multi-by-break 24 by a NOT gate 26e. ing.

Next, the operation of this embodiment configured as described above will be explained with reference to the time chart shown in FIG.

When the barcode reader 1 is installed on the dedicated installation stand 13, the charging input terminal 11a of the barcode reader I example
, llb are the charging output terminals 17a, 1 of the dedicated installation stand 13
7b, the secondary battery 20 is charged to the upper limit voltage by the charging circuit 15.6 Also, when the barcode reader 1 is separated from the dedicated installation stand 13 in order to use it, the secondary battery 20 is Charging stops. Power to the illumination light source 2 and various circuits during barcode pattern reading is normally supplied from the secondary battery 20 of the power supply unit IO.

That is, as shown in FIG. 3(a), when the terminal voltage V of the secondary battery 20 is greater than the reference voltage Vre t', the output signal S of the voltage monitoring circuit 23 (output of the comparator COM)
is at the "L" level as shown in FIG. 3(C). Also, at this time, the output signal s2 of the monostable multi-bi break 24 is at the "L" level as shown in FIG. There is.

Therefore, the output of the NAND gate 26d which uses this output signal S ("L" level) and the output -H"' of the NOT gate 26e becomes "H", and the output of the transistor 26e becomes "H".
6c is turned on, which causes MOS)-transistor 26a
becomes conductive as shown in FIG. 3(e), and power is supplied from the secondary battery 2o to each circuit of the barcode reader 1.

On the other hand, as the secondary battery 20 discharges while the barcode reader l is in use, the voltage monitoring circuit 23 detects that its terminal voltage V has dropped below the reference voltage Vref as shown in FIG. 3(a). Once detected.

The output signal S1 is "L" as shown in FIG. 3(c).
level to “H-level”.

When the monostable multivibrator 24 receives the l-level signal s1, the output signal S2 of the monostable multivibrator 24 becomes the output signal S, as shown in FIG. 3(d).
The state is "T1" for a predetermined time T from the rising edge of the signal.

When this "H" level signal S2 is applied to the transistor 25c of the display circuit 25, the transistor 25c becomes conductive and lights up the display element 25a for one hour.

This notifies the operator that the voltage of the secondary battery 20 has fallen below the reference voltage Vref' and that the barcode reader I is no longer usable.

Furthermore, when the NAND gate 26d of the switch circuit 26 receives the 'H' level output signal S1 from the voltage monitoring circuit 23, the 'H' level output signal S1 from the monostable multi-by-break 24 is applied.
When the level output signal S2 goes to the "L" level after T8\, the output of the NOT gate 26e is inverted to the -H- level.
The logic output of the D gate 26d becomes "L", turning off the transistor 26c.

As a result, the MOS)-transistor 26a as shown in FIG. 3(e)
As shown in FIG. 2, the power is cut off from the time when the output signal S2 falls, and the power supply from the secondary battery 20 to each circuit of the barcode reader I is stopped.

On the other hand, when the operator visually confirms that the display element 25a is lit, the power supply cable 19 connected to the external power supply terminal 18 of the external power supply circuit 16 is connected to the external power input terminal 12 of the barcode reader l.

Here, when the voltage monitoring circuit 23 determines that the external power supply voltage V2 supplied from the external power supply circuit 16 is equal to or higher than the reference voltage Vref' as shown in FIG. 3(b), the voltage monitoring circuit 23 outputs The signal S1 becomes "I-" level.

Accordingly, the output signal SI of the ``L'' level and the inverted output ``H'' of the NOT gate 26e are NAND
The logic output of gate 26d becomes 14", turning on transistor 26c. As a result, M of switch circuit 26
The O3I-transistor 26a becomes conductive again, as shown in FIG. 3(e), and supplies the power applied to the external power input terminal 12 to each circuit of the barcode reader I.

In this embodiment, when the voltage of the secondary battery 20 drops below the reference voltage, the display element 25a lights up to indicate that the barcode reader l is unusable, and at the same time,
The power supply from the secondary battery 20 is automatically cut off, and the operator connects the power supply cable 19 to the barcode reader.
By connecting to the external power input terminal 7-18 of the barcode reader 1, the barcode reader 1 can be used continuously.

Therefore, it is not necessary to interrupt the use of the barcode reader l until the secondary battery 20 is charged to the voltage of the reference voltage stage -L as in the conventional case, and the barcode reader l is not affected by the voltage drop of the secondary battery 20. It can be used immediately without being damaged, and it also enables stable, reliable and accurate readings.

Note that in the above embodiment, the switch circuit 26 has MO3I-
Although the case where a transistor is used has been described, the structure is not limited to this, and it is also possible to use a relay or other switching element.

Further, in the above embodiment, the voltage drop display circuit 25 includes an LED.
Although a display element is used, a buzzer or other notification device may also be used.

Further, the present invention is of course applicable not only to the barcode reader shown in the above embodiment but also to other cordless type information reading devices.

(Effects of the Invention) As explained above, according to the present invention, when it is detected that the voltage of the secondary battery built in the information reading main body side is below the reference value, this is notified and the voltage from the secondary battery is The power supply is cut off and the external power supply cable is connected to the information reader to enable power supply, so even if the voltage of the secondary battery drops below the standard value, the information reader can continue operating without interruption. and can be used.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram showing one embodiment of the present invention, Fig. 2 is a circuit diagram showing a specific example of the structure of the built-in power supply section in this embodiment, and Fig. 3 is a time chart for explaining the operation. . In the figure, l is a barcode reader, 10 is a power supply unit, I
la and llb are charging input terminals, 12 is an external power input terminal, 13 is a dedicated installation stand, 14 is a charging power supply unit, 15 is a charging circuit, 16 is an external power supply circuit, 17a and 17b are charging output terminals, 19 is the power supply cable, 20 is the secondary battery, 2
3 is a voltage monitoring circuit, 24 is a monostable multi-by-break,
25 is a voltage drop display circuit, and 26 is a switch circuit.

Claims (1)

[Scope of Claims] An information reading main body including a processing section that optically reads information attached to an object to be read and processes the read information, and a secondary battery that supplies power to the processing section, and the information reading main body. In an information reading device having a charging circuit for charging the secondary battery when not in use, when the voltage of the secondary battery is below a reference value, external power is supplied to the information reading main body from an external power supply unit. a power supply cable separably connected to the information reading main body; voltage monitoring means for monitoring the voltage of the secondary battery and external power supply voltage; and when the voltage monitoring means detects a voltage drop of the secondary battery. ,
Voltage drop notification means for notifying that the voltage is below a reference value; and when the voltage monitoring means detects that the voltage of the secondary battery is below the reference value, the power supply from the secondary battery is cut off. An information reading device comprising: a switch means that is turned on when the voltage of the secondary battery and the external power supply voltage are equal to or higher than a reference value.