JPH0652341A - Bar code reader - Google Patents

Abstract

PURPOSE:To improve the reading accuracy of a multi-direction scanning reader to output scanning beams in plural directions. CONSTITUTION:This bar code reader reads a bar code by emitting the scanning beams in the plural directions from plural scanners 40 equipped with emitting means 41 to emit the scanning beams, receiving means 42 to receive reflected beams based on the scanning beams and to convert them to electric signals and recognizing means 43 to recognize a bar code pattern from the electric signals. Further, the bar code reader has a detecting means 45 to detect the scanner, which first recognizes the bar code pattern, among the plural scanners 40, and emission control means 44 to stop the scanning beams emitted from the other scanners except the detected scanner for a prescribed period after the time of detection.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to improvements in bar code readers. In a stationary bar code reader used in a POS system or the like, when the bar code label attached to the product is read, the product is held by hand so that the bar code label surface is irradiated with the light beam. There must be. For this reason, reading may not be possible depending on the direction in which the product is held, and in order to eliminate this inconvenience, a multi-directional scanning reading device in which a plurality of scanners are arranged so that their scanning spaces cross each other has been studied. There is.

However, in this multi-directional scanning reading apparatus, since a plurality of light beams are scanned at the same time, there is a possibility that the reflected light of the light beams emitted from other scanners will be superimposed and received by each scanner. There is a risk that the bar code may not be read or may be read by mistake. For this reason, it is necessary to eliminate erroneous reading due to light from other scanners in a bar code reader having a plurality of scanners.

[0003]

2. Description of the Related Art FIG. 11 is a diagram showing an example of a multi-directional scanning reading device,
FIG. 12 is a diagram showing a conventional example. FIG. 11 shows an example of the external appearance of a two-way scanning reading device in which two sets of scanners are provided and a light beam is scanned from two directions. It has vertical and horizontal reading windows a and b, and reading windows a and b. The respective scanners are arranged so that the scanning lights A and B respectively emitted from the scanner cross each other. Therefore, unless the operator hides the product by hand or the surface of the bar code label of the product is facing the front surface or the upper surface in the drawing, scanning / reading can be performed, and the operability is remarkably high. improves.

FIG. 12 shows an example of the structure of a two-way scanning reader. In the scanner SC-A, the scanning light A emitted from the laser diode LD1 scans the bar code label 50 a plurality of times by the optical system 1 including a polygon mirror and a three-sided mirror. Then, each reflected light passes through the same optical path as the emitted light, is condensed, is received by the light receiving sensor S1, and is converted into an electric signal.

The converted electric signal is amplified by the amplifier 2 and then binarized by the binarizing circuit 3. This binarized signal is further converted into white / black bar width data by the decoder 4 and then stored in a memory (not shown), and the processor CPU 35 determines whether or not this signal is a bar code. If it is verified and it is recognized as a barcode, it is converted into numerical data (demodulation).
To be done.

On the other hand, the optical system 11, the amplifier 12, the binarization circuit 1
3, Scanner SC-B consisting of decoder 14 etc. is also SC-
The same reading operation as A is performed, and the CPU 35 also demodulates the data received by the scanner SC-B at the same time, verifies the normality of each demodulated data, the agreement of multiple data, etc. The demodulated data is output to the POS terminal device.

In FIG. 12, a plurality of scanners SC-A, SC
-A shows an example of a scanner provided with a light source and a polygon mirror, respectively, but a scanner configured to obtain a plurality of scanning lights by irradiating one polygon mirror with a beam from a plurality of different directions, and A scanner or the like configured to disperse light emitted from one light source and obtain scanning light respectively is also defined as a plurality of scanners.

[0008]

In a conventional multidirectional scanning reader having a plurality of scanners, a plurality of beams are simultaneously scanned. For this reason, depending on the shape and orientation of the product, the reflected light from the light beam of the other scanner may be superimposed and received, and the barcode may not be read or may be read by mistake.

In view of the above problems, the present invention provides a bar code reading apparatus having a plurality of scanners, which prevents a decrease in reading accuracy due to reception of reflected light of another scanner. To do.

[0010]

In the principle diagram of the present invention, reference numeral 40 denotes a plurality of sets of scanners, each of which comprises an emitting means 41, a receiving means 42 and a recognizing means 43. 45 is a detection means,
Of the plurality of scanners, the scanner that first recognizes the barcode pattern is detected. An emission control unit 44 stops scanning light emitted from other scanners except the scanner that first detects the barcode pattern for a predetermined period from the time of detection.

[0011]

Function: A plurality of scanners 40 are simultaneously operated to scan the light beam in a plurality of directions. The detection means 45 detects the scanner 40 that first recognizes the barcode pattern among the plurality of scanners 40, and the emission control means 44 detects the emission of the scanning light of the other scanners except the detected scanner at the detection time point. To stop for a predetermined period. As a result, the scanning light is emitted only from the scanner that scans the barcode label from the best direction, and therefore the reflected light of the scanning light of the other scanner 40 is not received, which is a characteristic of multidirectional scanning. Improved operability is achieved. The stationary scanner scans the barcode label a plurality of times.

As a method of detecting the scanner that first recognizes the bar code, the scanner that first recognizes the start pattern indicating the beginning of the bar code is detected, the start pattern is recognized, and a predetermined bar code pattern (multiple For example, the first scanner that recognizes the first character of the characters) is detected. this house,
This method is effective in preventing the light from being turned off due to the incorrect recognition of the start pattern.

Further, as a predetermined period for turning off the light, a period until the reading of the bar code is completed, a period until the stop pattern indicating the end of the bar code is detected, and a constant time by the timer (scanning time to the stop pattern, For example, there are a fixed value calculated from the scanning speed, the label length, etc.), the time to the stop pattern predicted by calculating the scanning time of the start pattern, and the like.

Instead of turning off the light, there is a method of reducing the amount of light emitted so that the barcode can be read. As a result, even if the start pattern is erroneously recognized, the barcode can be read by another scanner having a reduced light amount, so that the operability can be prevented from being degraded.

The above is a method in which light beams are simultaneously scanned in a plurality of directions by a plurality of scanners, only the scanner that first recognizes the bar code pattern is turned on, and the other scanners are turned off. Even if the scanning lights are alternately blinked so that the scanning lights do not overlap each other in time, the influence of the scanning lights of other scanners can be prevented.

In this case, switching is performed at a time interval (preferably as high as possible) narrower than the scanning time of the minimum width bar, and the received signal is sampled and held in synchronization with the lighting period to reproduce the original electric signal.

As described above, in a bar code reading apparatus having a plurality of scanners, only one set of scanners that best faces the bar code label emits scanning light and scans, or alternately scans in time. Therefore, the reading accuracy of the multi-directional scanning reading device can be prevented from being deteriorated without being influenced by the scanning light of other scanners.

The scanner 40 may be provided with a light source, and a light beam emitted from one light source may be divided into a plurality of beams and supplied to a plurality of scanners 40, respectively. Receiving means 42 for radiating scanning light in a plurality of directions by the scanner 40 and receiving reflected light for each scanning light, and recognizing means for recognizing a barcode.
If it has 43, it can be applied.

[0019]

FIG. 2 is a block diagram of the first embodiment, FIG. 3 is a diagram showing an example of a pattern recognition method, FIG. 4 is an operation flow chart of the first embodiment, and FIG. 5 is an operation flow chart of other embodiments. FIG. 6, FIG. 6 is a diagram showing another embodiment for determining the turn-off time, FIG. 7 is a time chart diagram of FIG. 6, FIG. 8 is a configuration diagram of the second embodiment, FIG. 9 is a time chart diagram of FIG. 10 has 1 light source
It is an explanatory view of a multi-directional scanning reading device in the case of one piece. (First Embodiment) In the second embodiment, in the two-direction scanning reader shown in FIG. 11, only one of the scanners that first recognizes the bar code remains in the lighting state, and the light source of the other scanner is turned off for a predetermined time. An example of reducing the amount of light will be shown.

In the scanner SC-A of FIG. 2, LD1 is a laser diode, and S1 is a light receiving sensor. Although omitted in FIG. 2, the laser diode LD is used by the optical system 1 shown in FIG.
The light beam emitted from 1 is emitted to the outside of the device as scanning light A, and the reflected light of the scanning light A is received by the light receiving sensor S1 and converted into an electric signal. 23 is an automatic power control unit APC
Then, the turning on / off control of the laser diode LD1 is performed by the turning on / off command from the CPU 21. An amplifier 2 amplifies the electric signal converted by the light receiving sensor S1. A binarizing circuit 3 binarizes the electric signal amplified by the amplifier 2.
Decoder 4 has a bar width counter 5 having a binarization circuit 3 having 2
The black bar (for example, signal "1") width and the white bar (signal "0") width of the binarized binary signal are respectively counted, and the values are sequentially stored in the memory 6. Reference numeral 7 denotes an STP (start pattern) recognizing unit, which is bar width data of white / black bars counted by the bar width counter 5 (hereinafter, a bar code pattern is composed of a start pattern, first to sixth characters, and a stop pattern). When the start pattern is recognized and the start pattern is recognized,
The output of the sequencer 10 is advanced from "0" to "1", for example.
A character recognition unit 8 recognizes the character following the start pattern. When the character configuration is, for example, 6 digits, the output of the sequencer 20 is sequentially "2" to "" in accordance with the recognition of the first to sixth characters. Proceed to 7 ". An SPP (stop pattern) recognizing unit 9 recognizes the stop pattern, and when the stop pattern is recognized, advances the output of the sequencer 10 to "8". A sequencer 10 sends an interrupt to the CPU 21 by outputting "1" by recognizing the start pattern and outputting "8" by recognizing the stop pattern. As described above, when the sequencer 10 outputs "8", the bar width data of the bar code pattern (hereinafter referred to as bar code data) is stored in the memory 6.

Here, the structure of the scanner SC-B is as follows:
Since it has the same configuration as SC-A, its description is omitted. Although details of the APC 22 and APC 23 are omitted in FIG. 2, their outline will be described with reference to FIG. In FIG. 8, resistors R1, R2, R
3, the transistors TR1 and TR2, and the operational amplifier A1 form a drive circuit for the laser diode LD1. Now R2 oscillator
When the 28 side is low level, TR2 is turned off and the reference voltage Vr
A current flows through TR1 so that the + input of A1 given from 1 through R1 and the − input of A1 (voltage of R3) match.
In other words, a current proportional to Vr1 flows through LD1 and emits light.
Since the amount of light emitted from LD1 is proportional to this current, the amount of light can be controlled by controlling Vr1 or switching the value of R3. To turn off the light, TR2 may be turned on by setting the oscillator 28 side of R2 to the high level.
Therefore, the APC22 is configured so that the resistors R1, R2, R3, the transistors TR1, TR2, the operational amplifier A1 drive the LD1 drive circuit shown in FIG. 8 and the CPU21 turn-on / off command to turn TR2 off / on via R2. It is composed of a circuit that supplies a signal.

Reference numeral 21 is a processor CPU, which outputs "1" from the decoder 4 or the decoder 14 (start pattern detection).
One of the scanners (hereinafter referred to as SC-A) that recognized the start pattern faster was detected by the interrupt by
Outputs a turn-off command to the other scanner SC-B. And "8" output of the scanner SC-A on the lighting side (stop pattern recognition)
Then, the bar code data is read from the memory 6 on the lighting side and demodulated to convert it into numerical data. When the demodulation process is completed by scanning with the scanner multiple times (when read OK / NG is determined)
One of the scanners turned off at a predetermined point to be described later
Sends a lighting command to SC-B. The same reference numerals denote the same objects throughout all other drawings.

FIG. 3 shows an example of a method of recognizing a bar code pattern composed of 6-digit characters. Figure 3 (a)
Shows an example of the structure of a bar code pattern, which is composed of a left guard bar LGB, a 6-digit character, and a right guard bar RGB from the left. This barcode is
LGB is recognized as the start pattern when scanned from the left or right, and when scanned from the LGB side (scanning light A1, A3), depending on the direction in which the product is held by hand or the configuration of the optical systems 1, 11 etc. , RGB are recognized as stop patterns. Similarly, when scanned from the RGB side (scanning light A2), RGB is recognized as a start pattern and LGB is recognized as a stop pattern. In this way, this bar code pattern is configured such that the detection conditions for the start pattern and the stop pattern are the same no matter which direction is scanned, as in the UPC (Common Food Code). It is recognized by the detection position of the first character whose detection condition is different from that of other characters. UPC is actually LGB, 6-digit character, center bar CB, 6-digit character, RG.
In the UPC, this embodiment is LGB.
This corresponds to the case of demodulation when scanning between RGB.
Therefore, in UPC, between RGB-CB, RGB-C
CB when demodulating and combining by scanning between B
The same operation can be performed by providing a recognition unit.

Hereinafter, UPC (Common Food Code) will be shown as an example of the detection condition. The detection condition of the start pattern is T0> 3.5 × T1 and 0.9 × T2 <T1 <1.1 × T2 from FIG. 3 (b). The stop pattern detection condition is T2> T2 from FIG. 3 (c). > 3.5 × T1 0.9 × T1 <1.1 × T1 The first character detection condition is 3 × T2 <T3 <4 × T2 The second to sixth character detection conditions are as shown in FIG. 3 (d). From FIG. 3D, 0.75T4 <T3 <1.25T4. Therefore, each recognizing unit applies the above detection condition based on the obtained bar width data, and recognizes the pattern assigned to each self.

With the above configuration, the following control of turning on / off the scanner light source is performed. (Example of turning off the light from the time when the start pattern is first recognized until the reading operation of the bar code is completed) See Fig. 4 (1) The CPU 21 sends a lighting command to both APCs 22 and 23 to send LD1, LD2 Is turned on, and scanning light A, scanning light B
To the emitting state. Step (2) in FIG. 4 Both scanners SC-A and SC-B receive reflected light and binarize it to perform bar width conversion. During this time, decoder 4 and decoder 14 perform start pattern recognition operation. I'm repeating. Then, the output of the sequencer 10 of the decoder 4 or 14 which has recognized the start pattern is from "0" to "
It becomes 1 "and an interrupt is sent to the CPU 21. Step (3) By this interrupt, the CPU 21 recognizes the scanner (hereinafter referred to as SC-A) that has recognized the start pattern first (step), and the other scanner SC-B. A command to turn off the light is sent to the APC 23 (step), and thereafter the LD2 is turned off until the reading processing of the bar code label is completed.
As a result, the scanning light B from the scanner SC-B is stopped. (4) Reading operation such as bar width conversion is performed in the lighting side scanner SC-A (step), and the sequencer 10 of the decoder 4 is operated.
Is sequentially output and "8" is output, the interrupt is sent to the CPU 21 again. As a result, the data for one scan is stored in the memory 6
The CPU 21 resets the sequencer 10, reads the read bar code data (bar width data) from the memory 6 and converts (demodulates) it into numerical data, and stores it in a memory (not shown). To do. (5) Hereinafter, by scanning the scanning light A multiple times by the scanner SC-A side, a plurality of bar width data are obtained and demodulated respectively. A plurality of numerical data are verified for coincidence / non-coincidence, etc., and if normal, read OK, if abnormal, read NG to the operator by outputting a lighting command to the APC 23 and turn on LD2. (Step), wait for scanning the next bar code label.

The interrupt method has been described as a method for detecting the scanner that recognizes the start pattern.
Alternatively, the CPU 21 may periodically read (monitor) the outputs of the sequencer 10 and the sequencer 16.

As described above, only the light source (LD1) of the scanner (SC-A) on the side that first recognizes the start pattern is turned on, and the light source (LD2) of the other scanner (SC-B) is read until the reading process is completed. Since the light is turned off, the reflected light of the scanning light is not received by the SC-A, and the reading error is reduced. (Example of turning off the light for a predetermined time after detection of the start pattern) FIG.
Reference A method of performing the extinguishing operation each time the start pattern is detected, that is, each time the barcode label is scanned, will be described below with reference to FIGS. 2 and 5. In addition, in this method,
A method of determining the turn-off time of the other scanner by counting a predetermined time calculated in advance or a predetermined time determined by measurement, and a method of predicting the turn-off time using the measurement value of the scanning time used for start pattern recognition ( In each case, there is -a or less in FIG. (1) A method of turning on the scanner that has been turned off after a certain period of time has passed after detecting the start pattern.

Both LD1 and LD2 are turned on, and the LD of the scanner (SC-A) that recognizes the start pattern first
1 turns on, and turns off LD2 of the other scanner SC-B. Then, the reading operation is performed by the scanner SC-A on the lit side (from the step-to-a turn-off command output). The steps up to this point are the same as the steps up to FIG. Where CP
U21 sets a predetermined time in the timer 24. The timer 24 is down-counted every time, and when the value becomes "0", an interrupt is generated to the CPU 21,
The CPU 21 outputs a lighting command to the APC 23 (step).

Here, if one scanning time of the bar code label is set as a fixed time, the detection of the scanner which previously recognized the start pattern and the output operation of the turn-off command are performed every scanning. The certain period of time may be obtained in advance by measurement, but may also be obtained by calculation from the scanning width of the scanning light, the label width and the like. At this time, there is a margin for the measured value or the calculated value because it is affected by the relative position of the product and the device. The time required to scan the UPC standard label with an actual device is about 100 microseconds. (2) A method of turning on the scanner that is turned off after a predetermined time that is predicted from the time measurement at the time of recognizing the start pattern after the start pattern is detected.

The same operation as (1) for setting the fixed time in the timer 24 is performed, but instead of setting the fixed time in the timer 24, one label scanning time is set by using the counted time for recognizing the start pattern. Predict and set the predicted value in the timer 24. This prediction method is performed as follows. Generally, since the operator holds the product by hand and illuminates it with the scanning light A or the scanning light B, the direction of the scanning light with respect to the bar code label is different each time as in the scanning lights A1 and A3 of FIG. One scanning time for the scanning light to scan the space,
Since the angle is constant, the label scanning time differs between A1 and A3. Therefore, in this method, the label scanning time is predicted using the time measured by the start pattern recognition.
That is, the STP recognition unit 7 stores the T1 or T2 time (for two modules) shown in FIG. 3 measured for start pattern recognition in the register 10a, and the CPU 21 reads this value at the time of interruption of start pattern recognition. For example 100
The scanning time for the module (in case of UPC standard) is calculated and set in the timer 24. As described above, the time can be set according to the scanning direction of the product. (Method of lighting from start pattern detection to stop pattern recognition) Refer to -b and below in Fig. 5 Both LD1 and LD2 are turned on, and LD1 of the scanner (SC-A) that first recognizes the start pattern is turned on. Then, turn off LD2 of the other scanner SC-B. And
The reading operation is started by the scanner SC-A on the lit side (from the step-to-a turn-off command output). Up to this point,
It is the same as the steps up to. The scanner SC-A that has recognized the start pattern subsequently recognizes the first to sixth characters with the scanner SC-A, and the SPP recognition unit 9 finally recognizes the stop pattern. This will cause an interrupt to the CPU21.
Then, the CPU 21 starts the demodulation operation as described above on the assumption that the bar code data is received, but at the same time, issues a lighting command to the APC 23 on the off side. As a result, the scanner that has recognized the start pattern again in the next scan is detected, and the unrecognized scanner is turned off.

The lighting control by the time setting and the relighting control by the stop pattern can be combined. Thereby, for example, it is possible to prevent a state in which the stop pattern is not detected and remains turned off. (Other Embodiments for Determining Light-out Time) In a stationary barcode reader, a polygon 33 and a three-sided mirror (mirrors x, y, z) are generally used for each scanner to scan in three directions. In this case, as shown in FIG. 6, an optical sensor 31 is provided at one end of the three-sided mirror, and the CPU 30 controls the time interval of the detection signal from the optical sensor 31 (see FIG. 7, Tm0, Tm1, Tm2 ...) With a timer.
The measurement time interval Tm0 / 3 (where Tm0 = Tm1 = Tm2 = ...
And the transit time of each three-sided mirror Tx0 = Ty0 = Tz0 = Tm0 /
3) and the scanning time of the beams X, Y, Z for scanning each mirror x, y, z (two sets in the case of bidirectional scanning) is predicted. Then, the turned-off scanner is turned on after the scanning time Tm0 on the lighting side has elapsed from the time of turning off the scanner. As a result, the turning-off operation is repeated every time each scanner scans in three directions. It should be noted that this method can be used in combination with a method in which a predetermined time elapses with a timer.

The above embodiment shows an example in which one of the scanners which has detected the start pattern is turned on and the other is turned off. The four methods of performing the relighting control are described above. Since the start pattern of is a very simple bar combination, it may be erroneously recognized. If the light source of the scanner on the side facing the label is turned off due to this misidentification, the stop pattern may not be detected, and even if the stop pattern is turned on, the reading may not be OK, resulting in poor operability and multidirectional The advantages of the reader are not obtained.
As a countermeasure against this, a method of first turning on the scanner that has recognized the start pattern and recognizing the first character and turning off the other scanners, or instead of turning off the other scanners, to the extent that a bar code signal can be detected, for example, with a predetermined amount of light There is a method of reducing the light amount to about 1/4.

In the method of FIG. 2, the output of the sequencers 10 and 16 representing the recognition of the first character in FIG.
An interrupt is generated to the CPU 21 by the "2" output instead of the 1 "output, and the CPU 21 controls the extinction by this interrupt.

The method of (1) is still affected by the light source of the scanner whose light amount is reduced to 1/4, but it is possible to read even if the start pattern is mistakenly recognized and the scanner on the side facing the label is reduced to 1/4 light amount. And the operability is improved. In this case, when the start pattern and the first character are detected by the 1/4 light quantity scanner, the lighting side is turned off. [Second Embodiment] In the second embodiment, turning on / off is alternately performed at a speed faster than the scanning time of the minimum width bar (usually about 3 to 10 times or more, and the higher the speed, the higher the accuracy), and the weight is mutually overlapped. It performs so-called chopping control of light, which is repeated at a timing such that it does not occur.
This is a method in which a sample hold (S / H) circuit samples in synchronization with the lighting time, holds the sampled value until the next sampling time, and reproduces a continuous signal.

In FIG. 6, 28 is an oscillator for generating a rectangular wave, and this rectangular wave has resistances R1, R2, R as shown in FIG.
3 、 Transistor TR1 and TR2 are supplied to the above-mentioned drive circuit composed of amplifier A1 to turn on / off LD1 (scan light is emitted when turned on, Fig. 9), and is also supplied to S / H circuit 25 and reflected. The optical signal of light is sampled and held to reproduce the bar code signal.

On the other hand, the rectangular wave output from the oscillator 28 is inverted by the inverter 29 and supplied to the drive circuit of LD2.
LD2 is turned on / off (scanning light is emitted when it is turned on), and the electric signal of the reflected light is sampled and held by the S / H circuit 26 by this signal, and reproduced as a bar code signal.
At this time, sample and hold circuits (S / H circuits) 25, 26,
Since the rectangular waves supplied to the respective drive circuits are inverted by the inverter 29, the scanning lights do not temporally overlap with each other.

FIG. 9 shows a pattern in which the reflected light corresponding to the scanning light emitted from the scanner SC-A is received to reproduce the bar code signal. When the scanning light emitted from the scanner SC-B illuminates the label, it is indicated by the dotted line in the figure.

Now, when the scanning light irradiates the bar code label at the timing shown in FIG. 9, the reflected light emits light.
Received by S1. Here, in FIG. 9, the higher level signal is the true white bar signal. The electrical signal corresponding to this reflected light is sampled in the S / H circuit 25 at the falling (or rising) timing (t1) of the rectangular wave output from the oscillator 28, and the sampled value is sampled at the next sampling time (t2). Hold up to. As a result, the S / H circuit 25 reproduces (samples and holds) the bar code signal corresponding to its own reflected light and outputs the bar code signal. Thereafter, as in the first embodiment, the binarization circuit 3
After binarizing with, the bar width is converted by the decoder 4 and CP
It is demodulated by U27.

Normally, only one of the scanners interrupts the barcode recognition from the decoders 4 and 14, but depending on the direction of the scanning light of the product, the interrupts from both the decoders 4 and 14 may occur. In this case, both bar code signals may be adopted for demodulation,
The bar code signal of the scanner with the higher interrupt may be adopted and demodulated.

As described above in the first and second embodiments, the light beams emitted from the scanners SC-A and SC-B do not overlap at least the data portion of the bar code in terms of time. Since they are scanned, they do not affect each other and the operability by multidirectional scanning is improved.

Although the scanner SC-A and the scanner SC-B have the same optical system respectively, for example, as shown in FIG. 6, the light source 34 and the light source 35 are polygons 33.
It is obvious that it can also be applied to a scanner that shares the.

Further, in the above-described embodiment, the two-direction scanning reading apparatus is used, and each scanner is provided with a light source, and the control is performed by turning on and off the light source. For example, as shown in FIG. 10, a light beam is split by a spectroscope 36 such as a half mirror, and the two light beams are set in two directions via a reflecting mirror 37 and the like.
Each is supplied as a light source to a scanner composed of polygons, three-sided mirrors, etc. Then, optical shutters 38 and 39 composed of, for example, liquid crystal are provided on the predetermined optical paths of the respective scanners as shown in the drawing, and the optical shutters 38 and 39 are shown in the first and second embodiments. If the on / off control is performed under the same conditions as described above, the scanning light emission of other scanners except the scanner that recognizes the barcode first, the reduction of the light amount,
And alternating scanning can be realized.

[0043]

As described above, according to the present invention, in a bar code reading apparatus which scans from a plurality of directions by a plurality of scanners, when one scanner recognizes a bar code, does the emission of the scanning light of the other scanner be stopped? , Or to reduce the amount of light, or to alternately blink the light source. Since the barcodes can be read without being affected by the scanning beams, the feature of having multiple scanners It can be fully demonstrated.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of a first embodiment.

FIG. 3 is a diagram showing an example of a pattern recognition method.

FIG. 4 is an operation flowchart of the first embodiment.

FIG. 5 is an operation flowchart of another embodiment.

FIG. 6 is a diagram illustrating another example of determining the turn-off time.

FIG. 7 is a time chart diagram of FIG.

FIG. 8 is a configuration diagram of a second embodiment.

9 is a time chart diagram of FIG.

FIG. 10 is an explanatory diagram of a multi-directional scanning reading device when there is one light source

FIG. 11 is a diagram showing an example of a multi-directional scanning reading device.

FIG. 12 is a diagram showing a conventional example.

[Explanation of symbols]

1 Optical system 2 Amplifier 3 Binarization circuit 4 Decoder 5 Bar width counter 6 Memory 7 STP recognition unit 8 Character recognition unit 9 SPP recognition unit 10 Sequencer 10a register 11 Optical system 12 Amplifier 13 Binarization circuit 14 Decoder 21 Processor C
PU 22 Automatic power control unit APC 23 Automatic power control unit APC 24 Timer 25 S / H circuit 26 S / H circuit 27 Processor C
PU 28 Oscillator 29 Inverter 30 Processor CPU 31 Optical sensor 32 Timer 33 Polygon 34 Light source 35 Light source 36 Spectroscope 37 Reflector 38,39 Optical shutter 40 Scanner 41 Emission means 42 Reception means 43 Recognition means 44 Emission control means 45 Detection means R1 ~ R6 Resistor LD1 to LD2 Laser diode S1 to S2 Light receiving sensor A1 to A2 Operational amplifier TR1 to TR4 Transistor X, Y, Z mirror

Claims (4)

[Claims] 1. An emitting means (41) for emitting scanning light, a receiving means (42) for receiving reflected light based on the scanning light and converting it into an electric signal, and recognition for recognizing a bar code pattern from the electric signal. A plurality of scanners (40) each having means (43)
A bar code reading device for reading a bar code by emitting the scanning light in parallel in a plurality of directions by the scanner, wherein the scanner first recognizes a bar code pattern among the plurality of scanners. Detection means (45) for detecting, and emission control means (4) for stopping the emission of the scanning light of the other scanners except the detected scanner for a predetermined period from the detection time point.
4) A bar code reader comprising: 2. A plurality of light emitting devices, each of which has an emitting means for emitting scanning light, a receiving means for receiving reflected light based on the scanning light and converting it into an electric signal, and a recognizing means for recognizing a bar code pattern from the electric signal. Of the plurality of scanners, which is capable of reading a barcode by emitting scanning light in a plurality of directions and in parallel by the scanner. A bar code reading apparatus, comprising: a detection unit that detects the detected light emission amount; and an emission control unit that reduces the light amount of the scanning light emitted from another scanner other than the detected scanner for a predetermined period from the detection time point. 3. The detecting means detects a scanner which first recognizes a start pattern in a bar code, or detects the first scanner which recognizes the start pattern and subsequently recognizes a predetermined bar code pattern. The bar code reader according to claim 1 or 2, wherein the bar code reader is a bar code reader. 4. A plurality of emission means for emitting scanning light, receiving means for receiving reflected light based on the scanning light and converting it into an electric signal, and recognition means for recognizing a bar code pattern from the electric signal. Is a bar code reading device which reads a bar code by emitting scanning light in a plurality of directions and in parallel by the scanner, and a time shorter than a scanning time for scanning at least the minimum width bar of the bar code. And an emission control means for emitting each scanning light alternately at a timing not overlapping with each other, and an electric signal corresponding to its own scanning light from among the converted electric signals provided corresponding to each scanning light. A bar code reader, comprising: a receiving means for sample-holding.