JPH05151378A - Bar-code reader - Google Patents

Abstract

PURPOSE:To enlarge a portable range limited by length of a cable, etc., and to increase a degree of freedom for use by providing a power source detecting part and a power source switching part in the bar-code reader. CONSTITUTION:In the bar-code reader for irradiating a bar-code read object with light by using a polygon mirror 32 to which a power source is supplied from a placing table 31, a power source detecting part 51 and a power source switching part 52 are provided. By the power source detecting part 5l, a detecting signal is sent out, when it is detected that the bar-code reader is raised and the power source supplied from the placing table 31. is disconnected. By this detecting signal, the power source switching part 52 switches so as to fetch power from a polygon mirror 33 for driving the polygon mirror 32. In such a manner, by disconnection of the power source supplied from the placing table 31, it is possible to switch so as to fetch power from the polygon motor, and the number of pieces of cables between the placing table 31. and the bar-code reader can be decreased. Accordingly, a portable range limited by length of the cable, etc., is enlarged, and a degree of freedom for use can be increased.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to bar code readers. Bar codes are widely used in the distribution industry and industrial applications. Bar code readers that read these bar code symbols are broadly classified as pen, touch, gun and stationary. Pen type, touch type, and gun type are usually called as hand type because humans use them by hand, and they are usually held by hand, but even in stationary type, small and lightweight ones were developed. Something has been developed that can be used as a hand-type substitute when used off the stand.

The bar code reader targeted by the present invention is
The present invention relates to a bar code reader which is usually used as a stationary type and designed so that when a bar code printed or affixed to a large product or the like is read, the bar code reader is manually lifted to read the bar code symbol of the product.

[0003]

2. Description of the Related Art In a conventional stationary bar code reader, a laser oscillator is used as a light source, a laser beam is scanned by a polygon mirror or the like, and a bar code symbol is read by the reflected light.

The oscillation source of this laser light is the conventional He--Ne.
Gas lasers have been used, but recent advances in semiconductor technology have made it possible to use semiconductor lasers as light sources for bar code readers.

For this reason, the light source can be downsized, and a stationary bar code reader which is as light as the touch type and the gun type and small in size has been developed. This small stationary bar code reader is different from the conventional stationary bar code reader embedded in the counter in that it allows you to hold and scan the product with your hand. Methods are beginning to be proposed.

FIG. 7 is a block diagram of a conventional bar code reader. In the figure, 1 is an optical sensor, which receives reflected light from the barcode reading object 10 and converts it into an electric signal, and 2 is an A / D conversion circuit, which is an optical sensor
The output of 1 is amplified and binarized to be converted into a digital signal. Reference numeral 3 is a bar width counter, which is an A / D converter.
The time width of the digital signal which is the output of the conversion circuit 2 is counted using a clock of a constant cycle and converted into white and black bar width data.

Reference numeral 4 is a bar code detection circuit for detecting the corresponding bar width data of the black and white bar width data obtained by the bar width counter 3 in accordance with the bar code rules, and 5 is the data. A buffer, which is a barcode detection circuit
The number detected in 4 is temporarily stored.

Reference numeral 6 denotes an interface unit, which is a higher-level device.
21 sends and receives data and commands, and 7 is CP
U is for recognizing barcodes, controlling polygon motors, lasers, speakers, display lamps, switches, etc., and 8 is a read-only memory (hereinafter abbreviated as ROM).
That is, it stores a program for controlling the barcode reader.

Reference numeral 9 denotes a miscellaneous control circuit, which controls various drive circuits 11 to 15, and 10 is a bar code reading object, to which a bar code is attached. Is a polygon motor drive circuit for driving the polygon motor 33 that rotates the polygon mirror 32.

A laser drive circuit 12 drives a laser oscillator 17 which emits a laser beam for scanning to read a bar code, and a speaker drive circuit 13 drives a speaker which issues an alarm. Reference numeral 14 is a display lamp drive circuit for lighting the display lamp.

Reference numeral 15 is a restart switch, and the laser oscillator 17 is inactive when reading is not performed. Therefore, it is necessary to restart when reading, and 32 is a polygon mirror. There is a polygonal mirror for scanning laser light by rotating, 33 is a polygon motor for rotating the polygon mirror 32, and 17 is a laser oscillator for emitting laser light. To do.

Reference numeral 20 is a power supply, which is supplied with power from the stand 31 to supply power to each circuit, 21 is a host device, which gives a command to a bar code reader, and 22 is a bar code. A code reader, which is the object of the present invention, 31 is a stand on which a bar code reader is placed, which is connected to a host device by a connection line and receives power from a general power line.

The bar code reader drives the laser oscillator 17 by the laser drive circuit 12 to emit laser light. The polygon motor driving circuit 11 rotates the polygon motor 33 to rotate the polygon mirror 32 to scan the laser light, and the reflected light of the laser light that hits the barcode reading object 10 is detected by the optical sensor. The / D conversion circuit 2 amplifies the output of the optical sensor 1 to binarize it to convert it into a digital signal, and the bar width counter 3 counts the time width of the digital signal using a clock of a constant cycle and Bar width data converted to black and black bar width data and the white and black bar width data obtained by the bar width counter 3
The number is converted into a corresponding number based on the bar code convention by 4 and is temporarily stored in the data buffer 5, and is transmitted from the interface unit 6 to the host device 21 as read data.

FIG. 8 is an external view of a conventional bar code reader. In the figure, 34 is a cable, which is composed of a signal line and a power line between the bar code reader and a stand, and 35. A window is for emitting a laser beam for scanning a barcode, and is for taking in reflected light from an object to be read. Reference numeral 36 is a display lamp for performing a display from an apparatus to an operator, Reference numeral 37 is a restart switch for restarting the laser oscillator, and 38 is a handle for holding a bar code reader. In addition, the same reference numerals as those in FIG. 7 are the same.

When the bar code reader shown in the figure is used as a stationary type, when a bar code reading object is held in front of the window 35, the polygon mirror in the bar code reader 22 scans the laser beam from the window 35 to read the bar code reading object. The light hits the bar code of the object and the reflected light is detected by the optical sensor to read it. In addition, when using it as a hand type, the operator
The bar code reader 22 is moved so that the bar code attached to the bar code reading target is irradiated with the laser light emitted from the window 35 of the bar code reader 22. When the barcode reading object is large or cannot be moved, the reading is performed by such a reading method, but the cable 34 connects between the stand 31 and the barcode reader 22. Since it is connected, the moving range of the barcode reader 22 is limited, which is inconvenient.

[0016]

In this new mode of use, since the bar code reader, which is originally a stationary type, is used by hand, the interface cable and the power cable are lifted while being dragged. This is a great inconvenience for operators using bar code readers, and the handling of these cables has always been a problem.

In view of the above problems, the present invention reduces the number of cable lines and further reduces the number of cables, thereby expanding the portable range limited by the length of the cable and increasing the flexibility of use. Has a purpose.

[0018]

The above-mentioned problems can be solved by a bar code reader having the following structure. FIG. 1 is a principle diagram of the present invention.

In a bar code reader which is supplied with power from the stand 31 and irradiates a bar code reading object with light using the polygon mirror 32, the bar code reader is lifted to supply power to the bar code reader. A power supply detection unit 51 that detects the disconnection and sends a detection signal, and a polygon motor 33 that drives the polygon mirror 32 by the signal.
And a power source switching unit 52 that switches to take out electric power from the power source.

[0020]

Operation: The power supply detection unit 51 detects that the bar code reader is lifted and the power supplied from the stand 31 is cut off, and sends a detection signal.

The power source switching unit 52 switches to take out electric power from the polygon motor 33 which drives the polygon mirror 32 in response to the detection signal. Therefore, it is possible to switch the electric power supplied from the stand 31 to be taken out from the polygon motor 33 that drives the polygon mirror 32 when the power is cut off, thereby reducing the number of cables between the stand and the bar code reader. You can

[0022]

[Embodiment] According to the present invention, when a bar code reader is connected to a stand and a power supply path, the bar code reader operates so as to receive power from a power terminal provided on the stand, and is lifted from the stand and placed. When the power supply path to the stand is cut off, the inertia of the polygon mirror is used to supply power to the bar code reader using the polygon motor as a generator.

FIG. 2 is a block diagram of the bar code reader of the first embodiment of the present invention. In the figure, reference numeral 51 is a power supply detection unit, which detects that the power supply path from the stand 31 is cut off and sends out a detection signal, and 52 is a power supply switching unit, which is a power supply detection unit. Power is switched from the polygon motor 33 that drives the polygon mirror 32 according to the detection signal from 51, and 40 is a power supply terminal. When the bar code reader 22 is placed on the stand 31, the power is supplied by the terminal. The supply path is connected. In addition, the same reference numerals as those in FIG. 7 are the same.

FIG. 3 is a block diagram of a power source detecting section and a power source switching section according to the first embodiment of the present invention. In the figure, 25 is N
It is an AND circuit, and the polygon motor 33 from the CPU 7
Is a logical product of the signal for driving the power supply and the inverse logic of the detection signal indicating that the power is cut off. Reference numeral 27 is a reference voltage generator, which compares the power supply voltage supplied from the stand 31. Reference numeral 28 is a generator for generating a reference voltage, and a comparator 28 compares the power supply voltage supplied from the stand 31 with the voltage generated by the reference voltage generator to determine the power supply voltage supplied from the stand 31. Is higher than the reference voltage, it sends a detection signal "1", 29 is a switch, which switches between the power source supplied from the stand 31 and the polygon motor 33, and Tr1 is a transistor, Polygon motor
The power for rotating the 33 is controlled by the power source supplied from the stand 31. Reference numeral 51 denotes a power supply detection unit, which is composed of a reference voltage generator 27 and a comparator 28, and 52
Is a power supply switching unit, and includes a NAND circuit 25 and a transistor
It consists of Tr1 and switch 29. The same reference numerals are used throughout the drawings.

The polygon motor 33 has both inputs of the NAND circuit 25, that is, the signal for driving the polygon motor 33 from the CPU 7 is "1", and the output of the comparator is "1", that is, the power source from the stand 31. Is normal, NAND circuit 25
Output becomes "0", the transistor Tr1 becomes conductive, and the polygon motor 33 is supplied with power to rotate as a motor. At this time, the switch 29 is connected to the power supply terminal 40 side so that power is supplied from the power supply terminal 40 to each circuit.

If the operator lifts the bar code reader 22 to separate the power supply terminal 40 from the stand 31 and the power supply path is cut off, the voltage of the power supply terminal 40 starts to drop rapidly. The reference voltage generator 27 holds the voltage in the internal circuit and continues to generate the reference voltage. Therefore, the output of the comparator 28 is "0".
Therefore, the input of the NAND circuit 25 becomes "0" on one side, the output becomes "1", the transistor Tr1 becomes conductive, the polygon motor 33 is not supplied with power, and the switch is turned on.
29 is switched to the polygon motor 33 side, and the voltage due to the electromotive force generated by the rotation inertia of the polygon motor 33 is supplied to each circuit while continuing to rotate for a while due to the inertia.

As explained above, the bar code reader 22
When the robot is lifted from the stand 31, the polygon motor
The barcode reader 22 performs a reading operation using the power generated by 33 as a power source.

As a method of further enhancing the mobility of the bar code reader, the interface signal can be made wireless. FIG. 4 is a block diagram of a bar code reader according to the second embodiment of the present invention, which is adapted to be wireless. An interface using radio waves or light is effective. In the figure, reference numeral 53 is a transmission / reception circuit, which is a circuit for wirelessly communicating with a host device. By wirelessly receiving the command from the host device 21 and transmitting the read data to the host device 21, the host device 21 is not connected by a connection line, and the cable 34 between the stand 31 and the stand 31 is eliminated. FIG. 5 is an external view of a bar code reader according to the second embodiment of the present invention. In the figure, 39 is an antenna for the bar code reader 22 to transmit and receive signals, and 40 is a power terminal for supplying power when the bar code reader 22 is placed on the stand 31. Is to connect. It is shown that the cable between the bar code reader and the cradle is eliminated, so that the portable range limited by the length of the cable is expanded and the degree of freedom of use is increased.

However, the rotation of the polygon motor is at most 30.
The rotation can be maintained for only about a second. Therefore, it is necessary to alert the operator by displaying an alarm with an indicator lamp before the motor is completely stopped.

The third embodiment of the present invention improves on this point. FIG. 6 is a configuration diagram of a bar code reader according to the third embodiment of the present invention. In the figure, reference numeral 54 denotes a rotation speed detection unit, which monitors the rotation speed of the polygon motor 33 and sends a detection signal when the rotation speed falls below a predetermined rotation speed. In order to count the number of revolutions, there is a method of directly using a tachometer for counting the number of revolutions, and a method of indirectly measuring a voltage of an electromotive force of a motor proportional to the number of revolutions. Either method may be adopted. In this embodiment, a tachometer that directly counts the number of rotations is used, and its output is input to the CPU 7 and RO
Compare with the specified number of revolutions in M8.

For example, the miscellaneous control circuit 9 is instructed to display a green light when the rotation of the motor is sufficient, a red blink when the rotation of the motor has dropped, and a red light when the motor is about to stop. The miscellaneous control circuit 9 can drive the display lamp drive circuit 14 to issue such an alarm.

Since the bar code symbol can be read in a few seconds, after reading one symbol,
By promptly returning the bar code reader 22 to the stand 31, the bar code reader 22 can continuously read without stopping.

[0033]

As described above, according to the present invention, the conventional stationary bar code reader can be provided with the mobility equivalent to that of the hand bar code reader. The remarkable effect is that the transportable range limited by is expanded and the degree of freedom of use is increased.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of a barcode reader according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a power supply detection unit and a power supply switching unit according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a bar code reader according to a second embodiment of the present invention.

FIG. 5 is an external view of a bar code reader according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a bar code reader according to a third embodiment of the present invention.

FIG. 7 is a block diagram of a conventional barcode reader.

FIG. 8 is an external view of a conventional barcode reader.

[Explanation of symbols]

1 Optical Sensor 2 A / D Converter Circuit 3 Bar Width Counter 4 Bar Code Detection Circuit 5 Data Buffer 6 Interface 7 CPU 8 ROM 9 Miscellaneous Control Circuit 10 Bar Code Reading Object 11 Polygon Motor Drive Circuit 12 Laser Drive Circuit 13 Speaker Drive Circuit 14 Display lamp driving circuit 15 Restart switch 17 Laser oscillator 20 Power supply 21 Upper device 22 Bar code reader 25 NAND circuit 27 Reference voltage generator 28 Comparator 29 Switch 31 Stand 32 Polygon mirror 33 Polygon motor 34 Cable 35 Window 36 Display Lamp 37 Restart switch 38 Handle 39 Antenna 40 Power supply terminal 51 Power supply detection unit 52 Power supply switching unit 53 Transmitter / receiver circuit 54 Rotation speed detection unit

Claims (1)

[Claims] 1. In a bar code reader which is supplied with power from a stand (31) and irradiates a bar code reading object with light using a polygon mirror (32), the bar code reader is lifted and the stand ( 31) The power detection unit (51) which detects that the power supplied from the power supply is cut off and sends a detection signal, and the electric power is taken out from the polygon motor (33) which drives the polygon mirror (32) by the signal. A bar code reader characterized in that it is provided with a power source switching section (52) for switching as described above.