JPH103513A - Bar code reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate any expensive switch, and to reduce battery consumption. SOLUTION: A switch 22 is turned on, and a ground potential is impressed to an output control terminal 7 of an IC 4 for a DC/DC converter, and then a voltage converting part 21 converts a battery voltage into an operating voltage, and supplies it to a CPU 3 which operates a bar code signal processing. An activating state detection signal is outputted from the CPU 3 which is turned into the activating state, and the transistor of a potential holding circuit 23 is turned on. Therefore, even when the switch 22 is turned off, the output control terminal of the IC 4 for the DC/DC converter is held to the ground potential. After the reading of a bar code, or after the lapse of a prescribed time, a reading end detection signal is outputted from the CPU 3, the transistor is turned off, and the holding of the ground potential is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code reader, and more particularly, to an improvement in a manual scanning type bar code reader.

[0002]

2. Description of the Related Art FIG. 2 shows an electric circuit unit housed in a bar code reader of this type, which includes a battery 1, a voltage conversion unit 2, a CPU 3 for processing a read bar code signal, and the like. Have been.

The voltage converter 2 has a DC / DC converter IC 4, and is connected to the battery 1 via a switch 5. Then, by pressing the switch 5 to turn it on, the DC / DC converter IC 4 operates, and a predetermined operating voltage is supplied to the CPU 3 from the output terminal 6 of the voltage converter 2. In this case, the DC / DC converter IC 4
Output control terminal 7 must be at a predetermined potential, for example, a ground potential. Reference numeral 8 denotes a cable for connecting a barcode reader to a barcode data processing unit (not shown).

[0004]

However, the conventional example of the above configuration has the following problems. At the time of startup, the switch 5 is turned on to connect the battery 1 as a power supply, and when the operation is stopped, the switch 5 is turned off and the battery is separated. Therefore, a large current flows at the time of on / off. Therefore, a switch having a large current capacity is required, which causes an increase in cost.

Also, as long as the switch 5 is turned on,
Since the current always flows through the voltage conversion unit 2 irrespective of bar code reading, there is a problem that the battery is consumed.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a bar code reading apparatus which does not require an expensive switch and reduces the consumption of a battery. .

[0007]

In order to achieve this object, a bar code reader according to the present invention converts a battery voltage into an operating voltage by a DC / DC converter for a CPU that performs bar code signal processing. In the voltage conversion unit to be supplied, a switch for applying a predetermined potential to an output control terminal of a DC / DC converter for controlling the output of the voltage conversion unit, and an operation voltage supplied from the CPU that has been activated and has been activated. And a potential holding circuit for holding the output control terminal of the DC / DC converter at a predetermined potential even when the switch is turned off in response to the activation state detection signal.

Further, after reading the bar code after the CPU is activated, or after a predetermined time has elapsed,
In this configuration, the potential holding circuit is released from holding the potential in response to the reading completion detection signal output from the CPU.

According to the above arrangement, the potential holding circuit holds the output control terminal at a predetermined potential after the CPU is activated by operating the switch provided at the output control terminal of the DC / DC converter once. A large current does not flow through the switch, and a small current capacity may be used. Further, the supply of the operating voltage is automatically stopped after reading the barcode or after a predetermined time has elapsed, so that the consumption of the battery is reduced.

[0010]

Embodiments of the present invention will be described below in detail. FIG. 1 shows an electric circuit unit housed in a barcode reader according to an embodiment of the present invention. 1, components having the same functions as those in FIG. 2 are denoted by the same reference numerals, and 21 is a voltage converter, 22
Is a switch for applying a predetermined potential (here, a ground potential) to the output control terminal 7 of the DC / DC converter IC 4 for controlling the output of the voltage converter 21, and 23 is a switch that once turns on the switch 22 and then turns off Anyway, it is a potential holding circuit for holding the output control terminal at the ground potential.

Next, the operation of this embodiment will be described. The battery 1 is connected to the voltage converter 21,
If a predetermined potential, that is, a ground potential, is not applied to the output control terminal 7 of the / DC converter IC 4, it does not enter the start-up state,
Accordingly, the CPU 3 is not supplied with the operating voltage, so that the CPU 3 does not enter the startup state.

When the switch 22 is turned on and a ground potential is applied to the output control terminal 7, the DC / DC converter IC 4 is activated, and the operating voltage is also supplied to the CPU 3 from the output terminal 6, and the CPU 3 is activated. When the CPU 3 enters the activation state, an activation state detection signal is output from the terminal 24 and the potential holding circuit 23
Even if the switch 22 is turned off at this time, the output control terminal 7 of the DC / DC converter IC 4 is kept at the ground potential, and the voltage converter 21 continues to supply the CPU 3 with the operating voltage.

Therefore, the bar code reader is manually operated to scan over the bar code and read the bar code. Next, after reading the bar code or after a predetermined time has elapsed, the CPU 3 sets the terminal. 24 outputs a read end detection signal. With this signal, the transistor of the potential holding circuit 23 is turned off. Then, since the application of the ground potential to the output control terminal 7 is stopped, the DC / DC converter IC 4 stops operating, and at the same time, the CPU 3 stops operating.

In this embodiment configured as described above, the supply voltage to the CPU 3 is controlled by the switch 22 provided between the output control terminal 7 and the ground potential, and the apparatus is started. The switch does not require the current capacity of the switch when the battery is connected as described above, and the required function is achieved by a small and inexpensive switch. Also, once the switch 22 is pressed and activated, the potential holding circuit 23 operates until the barcode is read thereafter, and the operation is automatically stopped after the reading is completed or after a predetermined time has elapsed. Battery consumption can be prevented.

[0015]

As described above, according to the present invention,
This makes it possible to start with a small and inexpensive switch, and to reduce battery consumption.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a circuit built in a barcode reader according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a circuit built in a bar code reader in a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery, 3 ... CPU, 4 ... DC / DC converter IC, 7 ... Output control terminal, 21 ... Voltage conversion part, 22
... switch, 23 ... potential holding circuit.

Claims (2)

[Claims] 1. A DC / DC converter for controlling an output of a voltage conversion unit in a voltage conversion unit that supplies a CPU that performs barcode signal processing by converting a battery voltage into an operation voltage by a DC / DC converter. A switch for applying a predetermined potential to the output control terminal of the CPU and an activation state detection signal output from the CPU that has been activated when an operating voltage is supplied. A potential holding circuit for holding an output control terminal of the converter at a predetermined potential. 2. After reading a bar code after the CPU is activated or after a predetermined time has elapsed,
2. The bar code reader according to claim 1, wherein the potential holding circuit releases the potential holding by a reading end detection signal output from the PU.