JPH07334606A - Optical code reading device - Google Patents

Abstract

PURPOSE:To provide an optical code reading device which can accurately decide the code given to an object to be identified that is carried by a transfer system. CONSTITUTION:The present position of a code is detected by a code position detector units 23a, 23b and 28 from the detecting position of the reflected light that is acquired from the beam scanning light, the head and end positions of an identified object bearing the code are detected by the identified object tracking units 30, 31 and 32 in the carrying direction of the identified object, and when the code-identified object correspondence deciding units 26 and 32 detect that the code is positioned between the head and end positions of the identified object based on the information on the code position and the information on the head and end positions of the object, a normal corresponding relation is judged between the code and the identified object. Meanwhile, if the code-code correspondence deciding units 26, 31 and 32 detect that the position information on plural codes are acquired between the head and end positions of the identified object, it is decided whether the same code is read and detected based on the result of comparison carried out among plural position information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention identifies an object to be identified by optically scanning and detecting a code (symbol) such as a bar code or a mark attached to an object to be identified such as goods, luggage and the like. And an optical code reader for the same.

[0002]

2. Description of the Related Art Such an optical code reading device scans a code such as a bar code or a mark attached to an object to be identified such as goods, luggage or the like with a beam scanning light and at the same time.
By receiving the reflected light from the code for the beam scanning light by the photoelectric conversion element, a photoelectric conversion signal corresponding to the change in the light intensity of the reflected light is obtained, and further, the photoelectric conversion signal is processed to obtain the code. Identify and judge.
That is, since the change in the light intensity of the reflected light has the pattern information unique to the code, the feature extraction of the code is realized by obtaining the photoelectric conversion signal, and the photoelectric conversion signal is based on the predetermined algorithm. By performing signal processing, decoding processing for the code is realized. Then, a plurality of predetermined types of codes are associated with each product or parcel, and the optical code reading for the purpose of identifying the product or parcel by identifying and judging each code. Equipment is used, typically PO
It is known to be incorporated in the S system.

In addition to the POS system, a predetermined pattern code for each type of goods and parcels is associated with each of a plurality of commodities and parcels so that a conveyor mechanism such as a belt conveyor system can be used. While these goods and parcels are being conveyed, by identifying and judging the respective codes, applications for identifying and sorting such commodities and parcels, that is, an optical code reader is used as a conveying system. It is well known that it is incorporated.

A schematic structure of a conveying system in which a conventional optical code reader is incorporated will be described with reference to FIGS. 10 to 17. In FIG. 10, one of the endless conveying belts 1 moving in a predetermined conveying direction y is shown. An optical code reading device 2 is provided on the side of the optical code reading device 2. In the optical code reading device 2, conveyed goods and parcels (hereinafter collectively referred to as identification objects) 3 enter a predetermined scanning area W. And a second optical sensor for detecting that the object to be identified 3 has passed the predetermined scanning area W and has been deviated, and a scanning area W of the conveyor belt 2. An optical scanning mechanism 6 for scanning the surface of the object to be identified 3 passing through the scanning region W by sweeping and irradiating a beam scanning light with a predetermined scanning angle, and a signal processing circuit (not shown) ing.

The first optical sensor comprises a light emitter 4s and a light receiver 4e which are arranged so as to face each other in a direction orthogonal to the transport direction y, and the tip of the object 3 to be transported is an optical path between them. When is blocked, it is detected that the DUT 3 has entered the scanning region W. The second optical sensor has a transport direction y.
Projectors 5 arranged to face each other in a direction orthogonal to
s and the light receiver 5e, and when the front end of the conveyed DUT 3 blocks the optical path between them, and then the rear end of the DUT 3 does not block the optical path between them again, the measured object is measured. Thing 3
Is detected to be out of the scanning area W. Then, the signal processing circuit recognizes a period during which the DUT 3 is passing through the scanning region W based on the detection signals output from the first and second optical sensors, and the optical signal is detected during this period. Scanning detection of the object 3 to be identified is performed by the type scanning mechanism 6.

As shown in FIG. 11, the optical scanning mechanism 6 irradiates _a spot-like beam scanning light within _a predetermined scanning angle α _a and conveys it at an angle of 45 ° with respect to the conveyance direction y. A first optical scanning system 6a that performs sweep irradiation by irradiating the belt 1 from above, and spot-shaped beam scanning light is irradiated in a range of a predetermined scanning angle α _b , and in the transport direction y. For example, it has a second optical scanning system 6b that performs sweep irradiation by irradiating the conveyor belt 1 from above at an angle of 135 °.

Therefore, as shown in FIG. 11, in the scanning region W, the first optical scanning system 6a sweeps and irradiates the beam scanning light along the virtual line La, and the second optical scanning system 6
b scans and irradiates the beam scanning light along the virtual line Lb, and when the code M attached to the identification object 3 passes on these virtual lines La or Lb, it corresponds to the pattern of the code M. The reflected light whose light intensity changes can be transmitted to any of the optical scanning systems 6a,
When 6b receives the light, it generates a photoelectric conversion signal.
That is, the feature extraction of the code M is performed by generating the photoelectric conversion signal. Then, the signal processing circuit performs a decoding process of the code M by processing the photoelectric conversion signal based on a predetermined algorithm.

Further, the optical scanning mechanism 6 is shown in FIGS.
As shown in FIG. 4, there is also one having an optical scanning system 6c for sweeping and irradiating two beam scanning lights along virtual lines La and Lb intersecting with each other at a substantially central portion in the scanning region W. That is, the optical scanning system 6c has, for example, a mechanism having the functions of the first and second optical scanning systems 6a and 6b together.
Two independent spot-shaped beam scanning lights are emitted from substantially the same emission position so as to form a predetermined scanning angle and a predetermined angle with respect to the transport direction y. Then, when the code M attached to the object to be identified 3 passes through these virtual lines La or Lb, photoelectric conversion is performed by receiving reflected light whose light intensity changes corresponding to the pattern of the code M. A signal is generated, and the signal processing circuit performs a decoding process of the code M by processing the photoelectric conversion signal based on a predetermined algorithm.

Although any of the optical scanning mechanisms shown in FIGS. 11 to 14 has the same function, the optical scanning mechanism shown in FIGS. 13 and 14 can narrow the scanning region W, Excellent in transport efficiency. Regarding a transport system incorporating such a conventional optical code reader, JP-A-2-170290 and JP-A-2-170290
No. 93992 is disclosed.

[0010]

By the way, in a transport system incorporating an optical code reader having a scanning function capable of improving the transport efficiency as shown in FIGS. 13 and 14, a plurality of transport systems are provided. When the objects 3 to be identified are lined up in an orderly manner along the transport direction y of the belt conveyor 1 at a predetermined distance or more, or when the object M to be identified 3 is provided with a symbol M, etc. Under the condition that the optimum detection condition is satisfied, reliable scanning detection and code determination can be performed. However, when such optimum detection condition is not satisfied, as shown in FIG. A plurality of objects to be identified 3 and 3'while being rotated in an arbitrary direction with respect to the direction y are in a state of being close to each other (a state in which mutual conveyance intervals are narrow), and symbols M and M attached to each of them. Transported in close proximity To be, these codes M,
When M ′ moves in the scanning region W at the same time, or as shown in FIG.
Due to the close proximity of M ′, these codes M,
When M ′ moves in the scanning area W at the same time,
There was a problem that correct reading / judgment could not be performed.

In the case of FIG. 15, the respective symbols M and M ′ are in a relationship of being oriented in substantially the same direction, and as a result of being scanned by the beam scanning light emitted along the virtual line Lb, The symbol M ′ of the DUT 3 ′ positioned behind the symbol M attached to the DUT 3 that precedes the transport direction y is scanned and detected first. Therefore, although the code M actually corresponds to the object to be identified 3 and the code M ′ corresponds to the object to be identified 3 ′,
Since the code M ′ is scanned and read as the object 3 to be measured and the code M is attached to the object 3 ′ to be measured, a very serious judgment error occurs.

Further, as shown in FIG. 16, when one identification object 3 is provided with two reference symbols M and M ', the two reference symbols M and M'are of the same type. If so, virtual line L
The scanning reading result by the beam scanning light swept and irradiated along a and the scanning reading result by the beam scanning light swept and irradiated along the virtual line Lb match.
In this case, as shown in FIG. 17, the same result is obtained as when one code M is scan-detected at the intersection of the virtual lines La and Lb. Therefore, the conventional optical code reader cannot determine the difference between reading two codes M and M ′ as shown in FIG. 16 and reading one code M as shown in FIG. .

Further, in FIG. 16, two codes M, M '
If the types are different, the scanning and reading result by the beam scanning light emitted along the imaginary line La and the scanning and reading result by the beam scanning light emitted along the imaginary line Lb are different. These scan read results were merely treated as read errors.

Therefore, in the conventional optical code reader, there is a limitation in use (precondition) that only one code must be attached to one object to be identified,
The user or the like is required to pay close attention when pasting the sheet or the like on which the code M is printed on the object to be identified 3, and the complexity of such work has been pointed out. Again 1
Although it may be convenient to identify each of the objects to be identified 3 by a plurality of codes, there is also a problem in that it is not possible to cope with such a usage situation due to the above-mentioned preconditions.

The present invention has been made in view of the above-mentioned problems of the prior art. Correspondence between the object to be identified and the code attached to the object while allowing various conveyance states of the object to be identified. An optical code that improves the relationship determination accuracy and that can determine the identity of the scanning read result even when a plurality of codes are attached to one object to be identified, and that can identify the object to be identified. It is intended to provide a reader.

[0016]

In order to achieve such an object, the present invention provides a beam scanning beam for scanning a code (for example, a bar code) attached to an object to be identified which is conveyed by a conveying system. At the same time, it is intended for an optical code reader which detects the reflected light of the light beam and judges the above-mentioned code based on the detection pattern of the reflected light.
A code position detection unit that detects the current position of the code from the detection position of the reflected light obtained by the beam scanning light, and a leading position and a rear end position in the transport direction of the object to be identified with the code. And an object-to-be-identified tracking unit that sequentially detects, information on the position of the code detected by the code-position detection unit, and a start position and a rear-end position of the object-to-be-identified detected by the object-to-be-identified tracking unit. A code that detects that the position of the code exists between the leading position and the trailing end position based on the information and determines that the code and the object to be identified have a normal correspondence relationship. An identification object correspondence determination unit is provided.

Here, as one embodiment of the code position detecting unit, when a code is detected by beam scanning by an optical scanning system, the information data of the scanning angle at the time of the detection is determined by a predetermined geometrical operation method. Code position data (Dp indicating the position of the code in the three-dimensional orthogonal coordinate system)
a, Dpb), and the code data (B
Ca, BCb) and first time data (TMa, TMb) indicating the time at the time of detection are generated.

In one embodiment of the above-mentioned object tracking unit, the movement amount of the object to be identified by the conveying system is sequentially detected by the movement detection sensor, and the direction of conveyance of the object to be identified is based on the information data of the movement amount. By _{obtaining the} amount of movement of the object, the object position data (Dy) indicating the position of the object in the orthogonal coordinate system is obtained, and the second time data (D _TMy ) indicating the time when the amount of movement is obtained is obtained. It is configured to occur.

In one embodiment of the code identified object correspondence determination unit, the identified object position data (Dy) and the second time data (D _TMy ) sequentially obtained by the identified object tracking unit are sequentially stored. It has a moving position storage area (B), and the data (Dpa, Dpb), (BCa, BC) from the code position detecting unit.
b) and (TMa, TMb) are generated, the identified object position data (D) associated with the second time data (D _TMy ) equal to the first time data (TMa, TMb) among them is generated.
y) is searched from the movement position storage area (B), and further, the identified object position data (Dy) and the code position data (Dp).
a, Dpb), the position of the code in the object to be identified is obtained, and the distance data (DMpay, DMpby) between the code objects and the code data (BCa, BCb) are stored in the code information storage area (C). , D), the data of the true positional relationship between the object to be identified and the code is obtained.

Further, instead of or in addition to the code identified object correspondence determining unit, the code position detection is performed between the leading position and the trailing end position of the identified object detected by the identified object tracking unit. When the presence of a plurality of code positions detected by the unit is detected, a code-to-code correspondence determination unit that determines whether or not the same code is read and detected by comparing the positions of the plurality of codes. The configuration is provided.

[0021]

In the present invention having such a structure, the object tracking unit sequentially grasps the information on the moving position of the object to be identified, and the code position detecting unit reads the code read by the beam scanning. The contents (code data) and the scanning position information of the code are generated. The code identified object correspondence determination unit is based on information on the position of the code detected by the code position detection unit and information on the start position and the rear end position of the identified object detected by the identified object tracking unit. When it is detected that the position of the code exists between the head position and the rear end position, it is determined that the code and the object to be identified have a regular correspondence. That is, if the code currently being scanned by the beam exists between the leading end and the trailing end of the object to be identified, the condition that the code and the object to be identified have a normal correspondence is satisfied. , The coded object correspondence determination unit determines such a condition.

Further, the code-correspondence determination unit detects the presence of position information regarding a plurality of codes between the head and the rear end of the object to be identified, and compares the positions of the plurality of codes to identify the same. It is determined whether or not the code is read and detected. That is, by determining whether the plurality of position information is due to reading the same code a plurality of times or the plurality of position information is due to reading a plurality of different codes. , The identity of the code is determined.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical code reader according to the present invention will be described below with reference to the drawings.

First, the structure of the optical code reader in the state of being incorporated in the transport system will be described with reference to FIG. The optical code reading device 11 provided on one side of the endless conveyor belt 10 that moves in a predetermined conveying direction y has a height of an object to be identified 12 such as parcels or goods conveyed by the conveyor belt 10 (the conveyor belt). Height from the transport surface of 10) H
Height measuring unit for optically measuring the object to be identified 12
A first optical sensor for detecting the time when the object has entered the predetermined scanning area W, and the first optical sensor for detecting the time when the object to be identified 12 passes through the scanning area W and comes off to the carry-out side. The optical sensor 2 and the scanning area W on the conveyor belt 10 are swept and irradiated with a beam scanning light (laser beam) at a predetermined scanning angle to beam the surface of the identification object 12 passing through the scanning area W. It has an optical scanning mechanism for scanning, a movement detection sensor for sequentially detecting movement (conveyance amount) of the conveyor belt 10 in the conveyance direction y, and a control circuit unit 13 for performing signal processing and predetermined determination processing. There is.

The above height measuring units are arranged so as to face each other along a direction x orthogonal to the conveying direction y, and a pair of posts 1 erected on both sides of the conveying belt 10.
It has 4s and 14e.

On one side of the post 14s facing the post 14e, a plurality of light emitting diodes or other light projectors are arranged at regular intervals in the height direction (direction orthogonal to the x and y directions).
The light beams are attached along z, and the light beams in the form of fine spots are always emitted from the respective projectors toward the facing surface of the post 14e (the side surface facing the post 14s). That is,
All the light beams have equal intervals Δ along the height direction z.
It is adjusted to be H and parallel to the transport surface of the transport belt 10.

On the opposite surface of the other post 14e, a plurality of photo-receivers such as photodiodes for individually receiving the above-mentioned light beams (in FIG. 1, one photo-receiver is representatively shown by PD). ) Are attached to each other at equal intervals ΔH along the height direction z. In this way, the respective light emitters provided in the post 14s and the respective light receivers provided in the post 14e are in one-to-one correspondence with each other, and the height detection output from all of these light receivers in parallel is performed. The signal group SH is supplied to the control circuit unit 13.

The object to be identified 12 is the post 1
Height detection signal group S that changes depending on the beam light that is blocked and the beam light that is not blocked when passing between 4s and 14e
The control circuit unit 13 analyzes the on / off pattern of H to detect the height H of the object to be identified 12.
The number of light emitters and light receivers and the interval ΔH are set in advance at the time of system construction, depending on the size of the object 12 to be processed by the transfer system and the desired resolution.

The above first optical sensor is the conveyor belt 1
It is composed of a light emitter 15s such as a light emitting diode and a light receiver 15e such as a photodiode, which are arranged on both sides of 0 in opposition to each other in the x direction. The light emitter 15s always emits a spot-like beam of light toward the light receiver 15e. The light receiver 15e photoelectrically converts the light beam and supplies the carry-in detection signal IN to the control circuit unit 13. The heights of the light projector 15s and the light receiver 15e are adjusted so that the optical path of the light beam is located slightly above the transport surface of the transport belt 10. Then, when the tip of the conveyed object to be identified 12 blocks the optical path between the light projector 15s and the light receiver 15e, the control circuit unit 13 moves to the scanning region W of the object to be measured 12 based on the change of the carry-in detection signal IN. Determine the entry.

The second optical sensor is, for example, a light emitting diode or the like, which is disposed on the carry-out side separated from the first optical sensor by a predetermined scanning region W, on both sides of the conveyor belt 10 and facing each other in the x direction. The light emitter 16s and a light receiver 16e such as a photodiode are provided. The light emitter 16s always emits a spot-shaped beam light toward the light receiver 16e, and the light receiver 16e photoelectrically converts the beam light to carry out the detection signal O.
The UT is supplied to the control circuit unit 13. The heights of the light projector 16s and the light receiver 16e are adjusted so that the optical path of the light beam is located slightly above the transport surface of the transport belt 10.

Then, in the control circuit unit 13, the tip of the object to be identified 12 conveyed is such that the projector 16s and the light receiver 1 are connected.
Based on the change in the carry-out detection signal OUT when blocking the optical path between 6e, it is determined that the object to be identified 12 is passing through the scanning region W, and the rear end of the object to be identified 12 receives light from the projector 16s. Based on the change in the carry-out detection signal OUT when it is out of the optical path between the containers 16e, it is determined that the identification target 12 has left the scanning region W.

The above-mentioned movement detection sensor is used for the conveyor belt 10.
Roller 17s that contacts one end of the roller 17s and rotates at an angle proportional to the amount of movement of the conveyor belt 10 in the y direction,
Each time a predetermined angle is rotated, an encoder 17e that generates a movement detection signal SP that becomes a single pulse of logic "H" is provided, and information on such a rotation angle (the number of times the single pulse is generated corresponds to the rotation angle) The movement detection signal SP which it has is supplied to the control circuit unit 13. Then, the control circuit unit 13 detects the carry amount of the carry belt 10 from the number of times the single pulse of the movement detection signal SP is generated. In this embodiment, the so-called contact type rotary encoder is applied to the movement detection sensor, but the present invention is not limited to this.
A well-known movement detection sensor that can detect the carry amount of the carry belt 10 may be used.

The above optical scanning mechanism includes an optical scanning system 18
And the optical scanning system 18 includes a control circuit unit 13
The irradiation optical mechanism that irradiates the scanning region W with the beam scanning light at a predetermined timing according to the control of 1. and the condensing lens that condenses the reflected light reflected from the scanning region W, and collects the reflected light. A light receiving optical mechanism having a light receiving sensor such as a photodiode for conversion is built in, and the reflected light detection signal SE output from this light receiving sensor is supplied to the control circuit unit 13.

The irradiation pattern of the beam scanning light in this embodiment is similar to that shown in FIGS. 13 and 14, and an imaginary line L intersecting with each other in an X shape at a substantially central portion in the scanning region W.
a, Lb, and the optical axis direction (in other words, scanning angle) of the spot-like beam scanning light emitted from the built-in laser diode is changed at a constant speed by an irradiation optical mechanism having a polygon mirror or the like. By doing so, sweep scanning at a predetermined speed is realized. That is, the spot-like beam scanning light is swept within _a range of _a predetermined maximum scanning angle α _a , and a predetermined angle θ _a (for example, θ _a =
45 °) irradiates the conveying surface of the conveying belt 10 from above to realize sweep scanning along the imaginary line La, and also the spot-like beam scanning light within a predetermined maximum scanning angle α _b . By sweeping and irradiating the conveyor belt 10 from above with a predetermined angle θ _b (for example, θ _b = 135 °) with respect to the conveyance direction y,
A sweep scan along the virtual line Lb is realized. However, the laser diode for realizing the irradiation pattern along the virtual line La and the laser diode for realizing the irradiation pattern along the virtual line Lb may be provided separately and independently.
A single laser diode may be shared for forming both irradiation patterns. Further, in this embodiment, the laser diode is used as the light source, but the invention is not limited to this.
An infrared light emitting diode or other light source that emits a spot light beam may be applied.

Further, the irradiation optical mechanism and the light receiving optical mechanism are synchronously controlled by the control circuit unit 13, and the reflected light for the beam scanning light emitted along the virtual line La and the reflected light for the beam scanning light are emitted along the virtual line Lb. The reflected light with respect to the beam scanning light is received independently.

Next, the internal structure of the control circuit unit 13 will be described with reference to FIG. The optical scanning system 18 performs the respective sweep scans along the imaginary lines La and Lb on the respective irradiation optical mechanisms 20a and 20b and the light receiving optical mechanisms 21a and 21a.
21b independently. Also, in FIG.
The components shown in FIG. 1 are designated by the same reference numerals. Furthermore,
In order to clarify the technical content of the present embodiment, a case where a JIS standard JAN code symbol having a plurality of black bars set to a plurality of types of widths and intervals is applied as the code M will be described. Further, a space between each black bar is called a white bar.

The first irradiation optical mechanism 20a has a virtual line La.
The beam scanning light is swept and emitted along with, and the start pulse signal STa is output each time the tip (scanning start end) of the imaginary line La is emitted, and the first light receiving optical mechanism 21a outputs the beam scanning light. Receives reflected light. Similarly, the second irradiation optical mechanism 20b also sweep-irradiates the beam scanning light along the imaginary line Lb, and outputs a start pulse signal STb at each timing of irradiating the tip (scanning start end) of the imaginary line Lb. Then, the second light receiving optical mechanism 21b receives the reflected light of the beam scanning light.

The first counter 22a restarts in synchronization with each generation of the start pulse signal STa, counts the clock signal CK from the system clock generating circuit 100, and sequentially reads the count data DTa as a code. Output to the circuit 23a. The binarization circuit 24a compares the level of the reflected light detection signal SEa output from the first light receiving optical mechanism 21a with a predetermined threshold level Th, and logic "L" when SEa <Th, and logic "L when Th≤SEa. The binary data DEa of binary level which becomes H ″ is output.

The second counter 25a has the gradation data DE.
Each time the logic of a is inverted from "H" to "L" or from "L" to "H", the restart is repeated in synchronization with counting the clock signal CK, and at the time of the logic inversion, the count data DWa Is supplied to the code reading circuit 23a.

The code reading circuit 23a uses the count data DT.
In addition to inputting a and DWa, time data TM from the time circuit 110 is also input. The time circuit 110 is realized by a time base that outputs time data TM indicating the current time by continuously counting the clock signal CK.

Furthermore, these circuits 22 will be described with reference to FIG.
The functions of a, 23a, 24a, and 25a will be described. The upper side of the figure conceptually shows a state in which the DUT 12 is transported in the transport direction y, and the code (JAN code symbol) M attached thereto moves relatively to the virtual line La.
The displacement of the relative positional relationship between the symbol M and the virtual line La is represented by virtual lines La _{i to} La _{i + j} . Further, the respective scanning start ends are P _{i to} P _{i + j} , and the respective scanning end ends are E _{i to} E _{i + j.}
It shows with.

Focusing on a sweep scan along a relative virtual line La _i , a start pulse signal STa of logic "H" is generated when the beam scanning light reaches the scan start end P _i . Further, for example, if the scanning position of the beam scanning light is SPT ₁
The count data DTa when the scan start end P _{i corresponds} to the scan elapsed time τ _DTa from the scan start end P _{i
It is} also equivalent to the scanning distance from _i . Therefore, the count data DTa output from the first counter 22a has information on the scanning distance from each scanning start end in each virtual line to the present time. Further, since the second counter 25a repeats the restart in synchronization with the time of the above logic inversion, the width of each white bar (for example, as shown in the figure) during each period in which the logic value of the gradation data DEa is "H". 3) and the width of each black bar (for example, WB in FIG. 3) is measured during each period when the logical value of the gradation data DEa is “L”. Since the logic inversion time of the data DEa is synchronized with the beam scanning of the boundary portion between the white bar and the black bar, the count data DWa sequentially output from the second counter 25a in synchronization with this logic inversion time is , And has width information of each of the white bar and the black bar.

The code reading circuit 23a previously stores reference data of the JAN code symbol group. Whenever the history of the count data DWa from the second counter 25a is held and a new count data DWa is input, the history pattern and the code symbol of the width of the white and black bars of the count data DWa that has been input so far are stored. When the matching with the reference data of the group is compared and searched, and the code symbol having the matching is searched, the code data B indicating the code symbol
Ca, count data DTa indicating the scanning distance, and time data TMa indicating the current time are simultaneously output. For example,
Assuming that the beam irradiation position SPT _{2 in} FIG. 3 is the end portion of the code M, the history pattern of the count data DWa obtained by beam scanning up to this position SPT ₂ is JAN.
Since it coincides with any reference data of the code symbol group, therefore, the above data BCa, DTa, TMa are simultaneously output at the time of beam scanning this position SPT ₂ .

Further, these data BCa, DTa, T
Since the point at which Ma is simultaneously output is also the point at which detection of the code M is completed, the count data DTa indicating the scanning distance has information on the position of the code M on the virtual line La.

Therefore, the function of the code reading circuit 23a is to obtain the content information of the code M by the code data BCa,
Code M based on the count data DTa and the time data TMa
To generate the location information of. The code data BCa and the time data TMa are the code data processing unit 2
6, and the count data DTa is supplied to the angle conversion circuit 27.
Is supplied to.

The angle conversion circuit 27 converts the position where the code M exists into scanning angle data (hereinafter referred to as scanning angle data) Dαa based on the count data DTa. That is, as described above, the count data DTa has information on the distance from the scanning start end of the virtual line La to the position where the code M exists, and the first irradiation optical mechanism 20a and the first light receiving optical mechanism 21 are included.
Since the installation position of a is fixed, the position of the code M is converted into the scanning angle data Dαa by a predetermined geometric operation.

The coordinate calculation circuit 28 inputs the height data DH of the object to be identified 12 output from the height determination circuit 29. That is, the height determination circuit 29 includes a pair of posts 14s,
14e and the on / off pattern of the height detection signal group SH output from the height measurement sensor having the light projector and the light receiver is analyzed, and the number of off patterns is multiplied by the interval ΔH. Height data DH indicating the height H of the object to be identified 12 is supplied to the coordinate calculation circuit 28. still,
For the sake of explanation, although the time has come and went, since the object to be identified 12 passes through the height measuring sensor and then passes through the scanning region W, the coordinate calculation circuit 28 receives the height before inputting the scanning angle data Dαa. Input the data DH.

When the scanning angle data Dαa from the angle conversion circuit 27 is supplied, the coordinate calculation circuit 28 performs a predetermined geometric calculation based on the scanning angle data Dαa and the height data DH. (X, y, z) of the code M
The position in coordinates is obtained, and its three-dimensional coordinate data Dpa
To the read data processing unit 26. That is, as described above, the scanning angle data Dαa has information of the position of the code M on the virtual line La (corresponding to the position of the xy coordinate plane), and the height data DH is attached to the object to be identified 12. Since it has the information of the height of the code M (corresponding to the position in the z-axis direction), a predetermined geometric operation is performed based on these scanning angle data Dαa and height data DH. Position of the code M on three-dimensional coordinates (xa, ya, za)
The three-dimensional coordinate data Dpa having the above information is formed.

Next, a circuit cascade-connected to the second irradiation optical mechanism 20b and the second light receiving optical mechanism 21b for realizing beam scanning along the virtual line Lb will be described. In FIG. 2, circuits 22b, 23b, 24b, 25 connected to the second irradiation optical mechanism 20b and the second light receiving optical mechanism 21b.
Reference numeral b indicates the circuits 22a and 23 which are cascade-connected to the first irradiation optical mechanism 20a and the first light receiving optical mechanism 21a.
a, 24a, 25a.

The first counter 22b restarts in synchronization with the start pulse signal STb output in synchronization with the beam scanning of the scanning start end of the virtual line Lb by the second irradiation optical mechanism 20b, and the system is restarted. Clock generation circuit 100
The clock signal CK is counted and the count data DTb indicating the scanning distance is output.

The binarization circuit 24b compares the level of the reflected light detection signal SEb output from the second light receiving optical mechanism 21b with a predetermined threshold level Th, and if SEb <Th, logic "L", Th≤SEb. Then, the binary data DEb having a logic "H" level is output.

The second counter 25b has the gradation data DE.
The clock signal CK is counted by repeating the restart in synchronization with the logic inversion of a, and the count data DWb is output at the time of the logic inversion.

The code reading circuit 23b receives the count data DT.
b, DWb, and time data TM are input, and the reference data of the previously stored JAN code symbol group and the history pattern of the sequentially input count data DWb are compared and searched to obtain reference data having the same. Is searched, the code data BCb indicating the code symbol is searched.
And the count data DTb indicating the scanning distance and the time data TMb indicating the current time are simultaneously output. That is, the code reading circuit 23b, similar to the function of the code reading circuit 23a, reads the content information of the code M by the code data BCb.
Code M based on the count data DTb and the time data TMb
Generate the location information of.

The code data BCb and the time data TMb are supplied to the code data processing unit 26, and the count data DTb are supplied to the angle conversion circuit 27.

Further, the angle conversion circuit 27 uses the count data D
When Tb is input, the count data DTb is changed to the virtual line L
Then, the scanning angle data Dαb is converted into scanning angle data Dαb and supplied to the coordinate computing circuit 28.
By performing a predetermined geometric operation based on b and the height data DH of the object to be identified 12, the position of the code M at the (x, y, z) coordinates is obtained, and the three-dimensional coordinate data DPb is read and data processing is performed. Supply to the unit 26. That is, the three-dimensional coordinate data DPb will have a data position on the three-dimensional coordinates of the code M which is obtained by beam scanning along the imaginary line _{Lb (x b, y b,} z b).

Next, the movement status management circuit 30 in FIG.
The carry-in detection signal IN output from the light receiver 15e of the first optical sensor, the time data TM, and the movement detection signal SP from the encoder 17e are sequentially input. Then, when a decrease in the level of the carry-in detection signal IN (level decrease due to the optical path interruption) is detected, it is determined that a new object 12 to be identified has started to enter at this detection time t _s , and the object 12 to be identified has a high level. The data DH is stored in a predetermined storage area (shape storage area A described later) in the identification object processing unit 31. Furthermore,
The movement detection signal S from the detection time t _{s of the} new identification object 12
By cumulatively adding the number of P pulse generations, a movement amount Ly indicating the current position of the tip portion of the identification target 12 with the light projector 15s and the light receiver 15e as a reference (Ly = 0) is obtained. Then, every time the movement detection signal SP is generated, the movement position data Dy indicating the corresponding movement amount Ly and the time data D _TMy (corresponding to the time data TM) indicating the current sampling time are output at the same time for identification. Predetermined storage area in the object data processing unit 31 (movement position storage area B described later)
To be stored in sequence. Furthermore, at the time t _e when the object to be identified 12 has passed through the first optical sensor, the movement amount Ly obtained up to that point is used as the length data DL of the object to be identified 12 together with the height data DH. The data is stored in the storage area (shape storage area A described later).

As described above, the movement status management circuit 30 stores the height data D of the object to be identified 12 in the shape memory area A described later.
H and the length data DL are stored, and the movement amount data Dy indicating the head position of the identification object 12 is sequentially stored in the movement position storage area B described later. Since the height data DH of the object to be identified 12 is obtained first, the length data DL is stored at the time t _s when the height data DH is stored in the shape storage area A.
Is unknown. Therefore, at the time t _s when the height data DH is stored in the shape storage area A, “NULL” indicating that the length data DL is unknown or data indicating an extremely large value is stored in advance, and the length data DL is stored. Both of the height data DH and the length data DL of the shape memory area A are finally determined at the time t _e when is truly obtained.

Next, a memory map of various storage areas provided in the identification object data processing unit 31 will be described with reference to FIG. First, the shape memory area A shown in FIG. 9A, the movement position memory area B shown in FIG. 9B, the first code information memory area C shown in FIG. )
The second code information storage area D shown in is provided.

The shape memory area A has a plurality of address areas #A ₀ to #A _m-1 corresponding to the plurality of m objects to be identified which will pass through the scanning area W, respectively. In the address area, the height measuring circuit 29 is synchronized with the above-mentioned timing.
And every time the movement state management unit 30 supplies the height and length data DH and DL of each identified object, these data D
H and DL are paired and stored in order as described above.
It should be noted that the address area (unused address area) before the new data DH and DL is stored has no meaning in the NU.
The LL data is stored.

The moving position storage area B has a plurality of tables B ₀ each having a plurality of address areas #t ₀ to #t _n-1.
~ B _m-1 . That is, the first table B ₀
The address area # of the shape memory area A
Regarding the object to be identified related to A ₀ , the movement status management circuit 30 is synchronized with the pulse generation timing of the movement detection signal SP.
Position data Dy and time data D _TMy supplied from
And a plurality of address areas #t ₀ to #t _n−1 which are stored in the order of supply. Each of the remaining tables B _{1 to} B _m-1 also has a plurality of address areas #t ₀ to #t _n-1 . Therefore, the number m of tables equal to the number n of address areas of the shape memory area A is provided. Each table B _{0 to} B _m-1
The number m of address areas is determined to be an optimum number in consideration of the pulse generation period of the movement detection signal SP, the length of the identification object 12, the length of the scanning area W in the y direction, the resolution, and the like.

The first code information storage area C is a virtual line La.
Data BC obtained by sweep scanning along the line
The second code information storage area D is a virtual line L, which is a storage area used for specifying the code M based on a, time data TMa, and three-dimensional coordinate data Dpa.
Code data B obtained by sweep scanning along b
It is a storage area used for the process for specifying the code M based on Cb, the time data TMb, and the three-dimensional coordinate data Dpb.

However, since both have the same memory configuration, the first code information storage area C will be described as a representative, and each of them has a plurality of address areas #p ₀ to #p _k-1. Tables C _{0 to} C _m−1 . That is, to describe the first table C ₀ as a representative, the code data BCa related to the code M attached to the object to be identified specified by the data DH and DL of the address area #A ₀ of the shape memory area A And x coordinate data (hereinafter referred to as x coordinate data Dpax) in the three-dimensional coordinate data Dpa indicating the position of the code M, and a tip code indicating the distance from the tip of the identification object to the code M at the y coordinate. storing between distance data DMpay as a set, has a plurality of address areas _{#p 0 ~ # p k-1} . Then, and has a plurality of address areas #p ₀ ~ # p _k-1 Similarly, the people each of the remaining tables C ₁ ~C _m-1. Therefore, the number m of tables equal to the number m of address areas of the shape memory area A is provided. The number k of address areas in each of the tables C _{0 to} C _m-1 is determined to be an optimum number in consideration of the maximum number of codes attached to each identification object 12.

Similarly, the second code information storage area D also has a plurality of tables D _{0 to} D _m-1 each having a plurality of address areas #q ₀ to #q _k-1 , respectively. #
In q ₀ to #q _k−1 , code data BCb related to the code M attached to the object to be identified and x-coordinate data (hereinafter, referred to as data of the three-dimensional coordinate data Dpb indicating the position of the code M) , X-coordinate data Dpbx) and tip-to-code distance data DMpby indicating the distance from the tip of the identification object to the code M at the y-coordinate are stored as a set.

Next, the function of the code data processing unit 26 will be described with reference to the flowchart of FIG. As described above, in step 200, the code data BCa
When the time data TMa and the three-dimensional coordinate data Dpa are supplied, the following processing is executed. First, step 20
5, the object to be identified 12 to be focused is the target number i = 0.
Stipulate. Next, in step 210, the table B _i (subscript i corresponds to the target number) in the movement position storage area B is searched, and the time data D _TMy having a match with the time data _TMa within a predetermined allowable range is stored. _Is obtained, and further, the length data DL of the DUT corresponding to the table number is read from the shape storage area A, and the movement position data stored in the same address area as the time data D _TMy ( Data indicating the tip position of the object to be identified Dy
Read out. Furthermore, in step 220, the difference between the y-coordinate data (hereinafter referred to as y-coordinate data Dpay) in the three-dimensional coordinate data Dpa and the movement position data Dy, that is, from the tip of the identification object at the y-coordinate to the code M The inter-symbol distance data DMpay indicating the distance is calculated.

Then, in step 230, when the value of the end-to-code distance data DMpay is greater than or equal to 0 and less than or equal to the length data DL (0≤DMpay≤DL), the code M attached to the DUT 12 is measured. It is determined that the code data of
Related to the code data BCa and the x coordinate data Dpa of the three-dimensional coordinate data Dpa indicating the position of the code M.
x and the above calculated inter-symbol distance data DMpa
y is stored as a set in the earliest available address area of the table assigned to the corresponding object to be identified in the code information storage area C.

On the other hand, the leading end code distance data DMpa
When the value of y is DMpay <0 or DL ≦ DMpay, it is determined that the beam-scanned code M is attached to an object to be identified, which is different from the object to be identified. Then, in step 250, the next object to be identified 1
The target number i is incremented by 1 in order to focus on 2 '. That is,
When DMpay <0 or DL ≦ DMpay, it is determined that the code is attached to the surface of another object to be identified, and i = i + is referred to in order to refer to the information regarding the other object to be identified.
By the processing of 1, the next table B _{i + 1} in the movement position storage area B is set.

In this way, the code data processing unit 26
However, when the processing of steps 200 to 250 is repeated, each table in the code information storage area C corresponding to each identified object stored in each address area #A ₀ to #A _m-1 of the shape storage area A is displayed. The code BCa of the code M attached to the identified object, the x-coordinate data Dpax, and the tip-to-code distance data DMpay are stored. That is, the DUT to be identified and the information of the code M attached thereto are associated with each other and stored in the shape storage area A and the code information storage area C.

The code data processing unit 26 performs the same processing as steps 200 to 250 on the code data BC.
b, the time data TMb, and the three-dimensional coordinate data Dpb are supplied in synchronism with the supplied data, so that the second code information storage area D is similarly processed.

In this way, by performing the data processing on the first and second code information storage areas C and D, the object to be identified and the code data BC of the code M attached to it are identified.
a and BCb are stored in association with each other. As a result, it is possible to prevent a reading error, which is a conventional problem (see FIGS. 15 to 17), such as a case where a plurality of objects to be identified enter the scanning region W.

Next, the identification determination unit 32 shown in FIG.
Is a second light source including a light projector 16a and a light receiver 16b.
The carry-out detection signal OUT output from the optical sensor is input, and the carry-out of the identification target 12 from the scanning region W is detected based on the change pattern of the signal level of the carry-out detection signal OUT.

Then, in synchronism with the detection of the carry-out of the object 12 to be identified, first, the object data processing unit 31 for the object to be identified.
Code data BCa, B from the specific table of the code information storage areas C, D (table of the identification object to be identified)
Cb is searched, and if neither of the code data BCa and BCb exists, message data indicating that code reading is impossible is output. This message data is output to control the transport system. On the other hand, when one code data BCa, BCb exists in each code information storage area C, D, the code data BCa, BCb is output to output 2
It indicates that the individual symbols are attached to the same object to be identified.

Furthermore, when a plurality of code data BCa and BCb exist in each code information storage area C and D,
First, it is determined whether or not the x-coordinate data Dpax and the tip-end code distance data DMpay indicate substantially the same position. If they are substantially the same position, the common code data B
On the other hand, when it is not determined that the positions are substantially the same, a plurality of respective code data BCa are output, and further, the x coordinate data Dpbx and the front end code distance data DM are output.
It is determined whether pby indicates substantially the same position, and if the positions are substantially the same, the common code data BCb is output. On the other hand, if it is not determined that the positions are substantially the same, each of the plurality of code data BCb is output. Is output.

Incidentally, these plural data Dpax, D
Whether Mpay and the plurality of data Dpbx, DMpby are data indicating substantially the same position is determined by the actual size of the code (for example, the size of the bar code, the horizontal and vertical width 2.5).
X3 cm), the difference in code position is small (for example, 2 cm or less in terms of Euclidean distance). Further, the determination of the single code data by determining that the positions are substantially the same can be performed by selecting either one having a large number of digits of the read data or one having a small number of digits of the read data, Determination / determination based on a predetermined algorithm, such as determining that the data is code data.

After performing the above processing, the identification determination unit 32 clears the storage data of all the storage areas A, B, C, D in the identification object data processing unit 31 and newly writes the next data. Control is performed to prepare for reading the code of the object to be identified.

As described above, according to this embodiment, on the condition that the time data DTMy stored in the moving position storage area B and the detected time data TMa (or TMb) of the code M match with each other, Since the relation between the identified object and its code M is checked, it is possible to accurately determine whether or not the detected code M is an object attached to a predetermined object to be identified, and to identify the same object to be identified. The two codes attached to the object can be individually determined, and by detecting the code M, the identification accuracy of the object to be identified can be improved.

Various modifications of this embodiment are possible without departing from the scope of the present invention. For example, in beam scanning for measuring the position of the code, the scanning angles α _a and α _b during the sweep are made finer, and as shown in FIG.
In the beam scanning along the virtual line La, the scanning angle α _as at the scanning start end of the code M and the scanning angle α _ae at the scanning end end may be obtained. In this case, the position of the code M is
3-dimensional coordinates Pas (x _{the as} that obtained on the basis of the scan angle alpha _{the as,}
y _as , z _as ) and the three-dimensional coordinates Pae (x _ae , y _ae , z _ae ) determined based on the scanning angle α _ae .
On the other hand, similarly for the beam scanning along the imaginary line Lb, similarly, the scanning angle α _bs at the scanning start end of the code M and the scanning angle α _be at the scanning end end are obtained, and the position of the code M is set to the scanning angle α be. It determined based on _bs 3-dimensional coordinates _{Pbs (x bs, y bs,} z bs)
When the three-dimensional coordinates Pbe (x which is obtained based on the scan angle alpha _BE
be , y _be , z _be ).

When determining the position coincidence of the code data BCa obtained by beam scanning along the virtual line La, these three-dimensional coordinate data Pas, Pae,
Pbs and Pbe are used.

Further, these three-dimensional coordinate data Pas,
Pae, Pbs, Pbe may be used as they are,
In addition, {(x _as
+ X _ae ) / 2, (y _as + y _ae ) / 2, (z _as + z _ae ) /
2} and {(x _bs + x _be ) / 2, (y _bs + y _be ) / 2,
(Z _bs + z _be ) / 2} may be compared to determine the magnitude of these separation distances based on a predetermined threshold value. As the threshold value at this time, the data of the size at each coordinate of the code M {| x _as −x _ae |, | y _as −y _ae
|, | Z _as −z _ae |} and {| x _bs −x _be |, | y _bs −
y _be |, | z _bs −z _be |} or both may be used and a threshold value obtained by multiplying them by a proportional coefficient may be applied.

Furthermore, the position detection sensor is not limited to the case where a so-called rotary encoder is used, and for example, as shown in FIG.
As shown in FIG. 5, an optical position detection sensor 40 may be used in which a plurality of light emitters and light receivers are arranged facing each other on both sides of the conveyor belt 10. The plurality of projectors 40s of the position detection sensor 40 are arranged at predetermined equal intervals along the transport direction y and at positions slightly higher than the transport surface of the transport belt 10, and all of them are spot-shaped parallel to the x-coordinate direction. The beam light of is emitted. On the other hand, a plurality of light receivers 40
The e is arranged to face the plurality of projectors 40s so as to receive these light beams in a one-to-one relationship. The signal SP output from the projector when the optical paths of these light beams are blocked by the passage of the object to be identified 12.
The position of the object to be identified 12 is detected based on the pattern change.

Furthermore, it is also possible to provide a rotating disk that comes into direct contact with the transport surface of the transport belt 10, determine the moving speed from the rotating speed, and integrate it over time to determine the moving distance.

Furthermore, if the transport speed of the transport belt 10 is always constant, for example, as shown in FIG.
Projectors 4 facing each other in the x-coordinate direction on both sides of 0
It is equipped with two sets of optical sensors consisting of 1s, 42s and light receivers 41e, 42e, and after the tip of the DUT 12 passes the first optical sensor (41s, 41e), the next optical sensor (42s, 42e). The moving speed of the object to be identified may be measured and the cumulative moving amount (corresponding to the above-mentioned data Dy) may be obtained from the time difference until the object passes.

Furthermore, if it is guaranteed that the conveyor belt 10 operates at a predetermined conveying speed as planned, such a position detecting sensor can be omitted and the above-mentioned predetermined conveying speed can be used. Further, the cumulative movement amount of the identification object may be obtained based on the transport speed.

Further, when the conveying speed of the object to be identified 10 is constant, instead of the moving position recording area B shown in FIG.
As shown in FIG. 9, the tip of the DUT 10 is the first in FIG.
Of the optical sensor (15s, 15e), the time data D _TMy of the time, the data DS indicating the moving speed, and the moving position recording area B for storing the moving position data Dy indicating the position of the tip of the identification object 10. 'May be applied. If such a movement position recording area B'is applied, the tip position of the object to be identified 10 is equal to the installation position of the first optical sensor (15s, 15e), so that the table assigned to each object to be identified is dared to be displayed. It is not necessary to store the data, and the number of storage elements such as a random access memory can be significantly reduced.

Furthermore, in the above embodiment, the sweep scan is performed along the two imaginary lines La and Lb. Therefore, even when the same object is marked with two symbols,
The respective codes can be read and detected, but the present invention is not limited to such two sweep scans.
If three or more sweep scans are performed along three or more virtual lines, three or more codes can be read and detected, respectively.

Each of the constituent elements described above may be composed of a random logic circuit, or may be realized by a program converted into a firmware by applying a microcomputer system.

[0086]

As described above, according to the present invention,
Since the position of the object to be identified and the position of the code attached thereto are successively monitored, the correspondence between the object to be identified and the code can be surely matched. Then, while establishing the correspondence relationship between the object to be identified and the code, the reading of the code and the identification of the object to be identified based on the code are performed.
It is possible to significantly reduce the determination error of the object to be identified.

Therefore, since it is possible to determine a plurality of objects to be measured which pass through the scanning region, it is possible to narrow the interval of conveyance of the objects to be measured, and to identify many objects to be identified in a short time. It becomes possible to process, which contributes to the improvement of the transfer efficiency of the transfer system.

Furthermore, since each code is read while surely grasping the position of the code attached to the object to be identified, one or more codes read in the sweep scan by a plurality of beam scanning lights are mutually the same. It can be determined whether or not it is separate.

Therefore, even if the same object to be identified is marked with two or more symbols, it can be surely recognized, and various objects can be identified by adding two or more symbols of different types. Aspects are possible. In this way, it is necessary to attach a plurality of codes to the same object to increase the amount of information, for example, in the field of physical distribution such as the transportation industry where the types of packages handled and the types of destinations are very large. In the above, it exhibits an extremely excellent effect.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of an optical code reader according to the present invention installed in a transport system.

FIG. 2 is a block diagram showing an internal configuration of a control circuit unit in FIG.

FIG. 3 is an explanatory diagram for explaining a function of a control circuit unit.

FIG. 4 is an explanatory diagram showing a memory map of a storage area provided in the identification object data processing unit in the control circuit unit.

FIG. 5 is a flowchart for explaining the function of the code data processing unit in the control circuit unit.

FIG. 6 is an explanatory diagram for explaining the principle of a modified example of laser beam scanning.

FIG. 7 is an explanatory diagram showing a modified example of the position detection sensor.

FIG. 8 is an explanatory diagram showing still another modification of the position detection sensor.

FIG. 9 is an explanatory diagram showing another memory configuration of the storage area provided in the identification object data processing unit in the control circuit unit.

FIG. 10 is a structural explanatory view showing a structural example of a conventional optical code reader.

FIG. 11 is an explanatory diagram showing a configuration of a scanning optical system of a conventional optical code reader.

FIG. 12 is an explanatory diagram showing the principle of a scanning optical system of a conventional optical code reader.

FIG. 13 is an explanatory diagram showing the configuration of another scanning optical system of the conventional optical code reader.

FIG. 14 is an explanatory diagram showing the principle of another scanning optical system of the conventional optical code reader.

FIG. 15 is an explanatory diagram for explaining a problem of the conventional optical code reader.

FIG. 16 is an explanatory diagram for explaining another problem of the conventional optical code reader.

FIG. 17 is an explanatory diagram for explaining still another problem of the conventional optical code reader.

[Explanation of symbols]

10 ... Conveyor belt, 11 ... Optical code reader, 12
... Identification object, 13 ... Control circuit unit, 14s, 14e ...
Posts, 15s, 16s ... Projector, 15e, 16e ... Photoreceiver, 17s ... Roller, 17e ... Encoder, 18 ... Optical scanning system, 20a, 20b ... Irradiation optical mechanism, 21a, 2
1b ... Receiving optical mechanism, 22a, 22b ... 11th counter, 23a, 23b ... Code reading circuit, 24a, 24b
... Binarization circuit, 25a, 25b ... Second counter, 26
... code data processing unit, 27 ... angle conversion circuit, 28
... coordinate calculation circuit, 29 ... height determination circuit, 30 ... movement status management circuit, 31 ... identification object data processing unit, 40 ... position detection sensor, 40s, 41s, 42s ... projector, 40
e, 41e, 42e ... Photoreceiver, A ... Shape memory area, B ...
Moving position storage area, C ... First code information storage area, D ...
Second code information storage area, M ... Code, W ... Scan area, L
a, Lb ... Virtual line.

Claims (2)

[Claims] 1. A reflected light of the beam scanning light is detected while sweeping and scanning a code attached to an object to be identified which is conveyed in a predetermined conveying direction by a conveying system with the beam scanning light, and a detection pattern of the reflected light is formed. In an optical code reading device for determining the code based on the above, a code position detection unit for detecting the current position of the code from the detection position of the reflected light obtained by the beam scanning light; An object-to-be-identified tracking unit that sequentially detects a leading position and a rear-end position in the conveying direction of the object, information on the position of the code detected by the code position detection unit, and the object-to-be-identified tracking unit. When it is detected that the position of the code exists between the start position and the rear end position based on the information of the start position and the rear end position of the identified object, A code identification object correspondence determination unit that determines that there is a regular correspondence with the identification object. 2. A reflected light of the beam scanning light is detected while sweeping and scanning the code attached to the object to be identified which is conveyed in a predetermined conveying direction by the conveying system with the beam scanning light, and a detection pattern of the reflected light is formed. In an optical code reader for determining the code based on the above, a code position detection unit for detecting a current position of the code from a detection position of reflected light obtained by the beam scanning light; An object-to-be-identified tracking unit that sequentially detects the leading position and the trailing end position in the transport direction of the object, and between the leading position and the trailing end position of the object to be identified detected by the identified object tracking unit, When the presence of a plurality of code positions detected by the code position detection unit is detected, the same code is read and detected by comparing the positions of the plurality of codes. An optical code reading device, comprising: a code-correspondence determination unit for determining whether or not there is a code.