JPH09128471A - Code reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely read a bar code by making a focal distance match with distance to the bar code face whether the scanning direction of a laser beam is on the side of a parallel face or the side of a vertical face to a joint face. SOLUTION: A laser beam from a semiconductor laser 81 is converted into scanning light for deflection-scanning by galvano-mirrors 86 and 87 through a variable focal point optical system 84 to scan a bar code face added to a product on a belt conveyer. In this case, depending on whether the direction of the canning light with respect to the joint surface of the semiconductor laser is on the side of a parallel face or on the side of a vertical face compared with 45 angular degree with respect to the angle 45 deg. between a parallel face and a vertical face to the joint surface, the moving quantity of a focus lens to the distance between with the bar code face, namely the automatic adjusting characteristic of the focal point, is differentiated to control the focal distance to always match with the distance to the bar code face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code reading device for automatically reading a bar code attached to an article such as a product conveyed by a belt conveyor.

[0002]

2. Description of the Related Art As a code reader of this type, for example, the one disclosed in JP-A-51-19448 is known.
As shown in FIG. 10, the article 11 with the label 12 is placed on the belt conveyor 1 and conveyed, and the photodetectors 2-2 ′, 3-3 ′ and 4-4 ′ are used to convey the article 11 on the way. The height of is being detected. Further, a laser light source 5 is provided, and laser light from the laser light source 5 is used as scanning light through a light projecting and receiving separation mirror 6, a light projecting optical system 8, a focus position adjusting optical system 9 and a light scanning section 10, and this scanning is performed. The label 12 of the article 11 conveyed by light is scanned, and the reflected light is received by the photocell 7 via the optical scanning unit 10, the focus position adjusting optical system 9, the light projecting optical system 8 and the light projecting / receiving separating mirror 6. The label is read. Then, the photodetectors 2-2 ', 3-3', 4
The focus position adjusting optical system 9 is driven based on the height of the article 11 detected by -4 ', that is, the label position is detected, and the laser light is automatically adjusted so as to focus on the label.

[0003]

By the way, as shown in FIG. 11, when the semiconductor laser 13 is used as the laser light source, the laser beam 14 emitted from the semiconductor laser 13 has an astigmatic difference. That is, the laser light 14a that spreads in the semiconductor laser 13 in the direction parallel to the bonding surface.
And the laser light 14b that spreads in the direction perpendicular to the joint surface has different emission points 15a and 15b. The semiconductor laser 13 is
Near the emission surface 13a, it is wide in a direction parallel to the joint surface and narrow in a vertical direction (near field pattern), and at a position distant from the emission surface 13a, it is narrow in a direction parallel to the joint surface and wide in a vertical direction (far field pattern). Pattern) Has a beam divergence angle. That is, θh <θv. At this time, the position of the virtual beam waist formed inside the semiconductor laser 13 does not become one point from the divergence angles in the parallel and vertical directions, but a difference occurs. This is called astigmatic difference.

Therefore, when a semiconductor laser is used as the laser light source, even if the label position, that is, the focus position where the laser light is focused is automatically adjusted by detecting the distance from the label, the laser light is emitted from the semiconductor. Since the focus position shifts due to the astigmatic difference depending on whether the scanning is performed in the direction parallel to the laser bonding surface or in the direction perpendicular to the laser bonding surface,
There arises a problem that the laser beam cannot be correctly focused on the label. For example, if the automatic adjustment of the focus position is set with reference to the laser light that scans in the direction parallel to the semiconductor laser bonding surface, the label will be displayed if the laser light scans in the direction perpendicular to the semiconductor laser bonding surface. However, even if they are at the same distance, the focal point is deviated, and the light cannot be collected correctly.

Therefore, according to the first and third aspects of the invention, the focus is automatically adjusted depending on whether the scanning direction of the laser light emitted from the semiconductor laser is on the parallel surface side or the vertical surface side with respect to the bonding surface of the semiconductor laser. By making the characteristics different, the focal length can be made to match the distance from the barcode surface regardless of whether the scanning direction of the laser beam is on the parallel surface side or the vertical surface side. (EN) Provided is a code reading device that can be adjusted and controlled and can reliably read a barcode.

According to the second and third aspects of the present invention, when the scanning direction of the laser beam emitted from the semiconductor laser can be automatically changed based on the position and inclination of the bar code, the scanning direction of the laser beam is the semiconductor. By changing the automatic focus adjustment characteristic depending on whether it is on the parallel surface side or the vertical surface side with respect to the laser bonding surface, the laser beam scanning direction can be on the vertical surface side even if it is on the parallel surface side. Also, the present invention provides a code reading device capable of matching the focal length with the distance from the barcode surface, thereby always performing accurate focus automatic adjustment control, and reliably reading the barcode.

[0007]

The invention corresponding to claim 1 is:
An article carrying means for carrying an article with a bar code, a semiconductor laser, and a scanning optical mechanism for converging and deflecting laser light from the semiconductor laser to convert it into scanning light for scanning the bar code surface of the article. , Provided in this scanning optical mechanism, the focus automatic adjustment means for automatically adjusting the focus of the scanning light according to the distance to the bar code surface of the article, and the reflected light when the scanning light scans the bar code surface of the article. And a bar code reading means for receiving a bar code to read the bar code, the scanning direction of the scanning light with respect to the direction of the bonding surface of the semiconductor laser,
The automatic adjustment characteristic of the automatic focus adjustment means is determined by whether it is on the parallel surface side or the vertical surface side with a predetermined angle set between the surface parallel to this bonding surface and the surface vertical to this bonding surface. The focal lengths are made different by making them different.

According to a second aspect of the present invention, article conveying means for conveying an article having a bar code, height detecting means for detecting the height of the bar code surface of the article conveyed by the article conveying means, and the article A position / tilt detecting means for imaging the bar code surface of an article conveyed by the conveying means to detect the position and inclination of the bar code, a semiconductor laser, and a laser beam from the semiconductor laser is condensed and deflected. To convert the scanning direction of this scanning light into scanning light for scanning, and to properly scan the barcode surface of the article based on the information of the position and inclination of the barcode from the position and inclination detecting means. Variable scanning optical mechanism, and a focus automatic adjustment hand provided inside the scanning optical mechanism for automatically adjusting the focus of the scanning light based on the bar code surface height detection information from the height detection means. And a bar code reading means for reading the bar code by receiving the reflected light when the bar code surface of the article is scanned with the scanning light, and the scanning direction of the scanning light with respect to the direction of the bonding surface of the semiconductor laser, The automatic adjustment characteristic of the automatic focus adjustment means is changed depending on whether it is on the horizontal plane side or the vertical plane side with a predetermined angle set between the plane parallel to this joint surface and the plane perpendicular to this joint surface. This is to match the focal lengths.

According to a third aspect of the present invention, in the code reading apparatus according to the first or second aspect, the predetermined angle is set to 45 degrees, and the scanning direction of the scanning light is on the horizontal plane side or the vertical plane with respect to this angle. The automatic adjustment characteristic of the automatic focus adjustment means is changed depending on whether it is on the side.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a checkout system for automatically registering goods. FIG. 1 is an overall configuration diagram of the checkout system, 21 is a first checkout lane, 41
Is the second checkout lane. The basket placement tables 22 and 42 on which the shopping basket 61 is placed are arranged on one end side of each of the checkout lanes 21 and 41, that is, on the upstream side.

Belt conveyors 23, 43 are provided at the central portions of the checkout lanes 21, 41 as article conveying means.
Has been arranged. On the upstream side of the belt conveyors 23 and 43, a customer 62 is provided with a product basket 63, which is an item for sale by a customer 62.
Product loading areas 24 and 44 for taking out from and loading
Is formed. A bar code is attached to the product 63, and the customer places the product 63 on the product mounting areas 24 and 44 with the bar code surface facing upward. Cylindrical tunnel parts 25, 45 for blocking outside light are arranged in the intermediate parts of the belt conveyors 23, 43.
5, height measuring devices 26 and 4 as height detecting means
6. Imaging cameras 27 and 4 as position and tilt detecting means
7 and the variable scanning optical system bar code scanners 28 and 48 constituting the scanning optical mechanism are arranged.

The image pickup cameras 27 and 47 are arranged right above so as to monitor the entire image input area on the belt conveyors 23 and 43. The belt conveyor 23, 4
An unregistered product stacker 64 is commonly provided at a position sandwiched by the belt conveyors 23 and 43 on the downstream side of 3, and a register device 66 for an operator 65 to manually register the unregistered product stacker 64 at the center thereof. Also, a POS terminal 67 for registering products in the memory is arranged.

Registered product stackers 29, 49 for storing registered products 63a are arranged downstream of the checkout lanes 21, 41. Subtotal indicators 30 and 50 are provided near the registered product stackers 29 and 49, respectively. A drawer, a receipt printer, etc. are arranged near the register 66 and the POS terminal 67. The product loading areas 24 and 44 are provided with start buttons 31 and 51 for instructing the start of the product loading and end buttons 32 and 52 for instructing the end of the product loading. Display 3 for guidance display near the product loading areas 24, 44
3, 53 are arranged, and a speaker (not shown) for notifying the guidance by voice is arranged. In the case where the products coming out of the tunnel portions 25, 45 at the downstream ends of the belt conveyors 23, 43 are products for which barcode reading has failed, the product exclusion mechanism 34 for removing the products to the unregistered product stacker 64, 54 is provided.

As shown in FIG. 2, the height measuring devices 26 and 46 have two support columns 7 with a transportation path for the product 63 in between.
1, 72 are arranged to face each other, a plurality of light projecting elements 73 made of LEDs or the like are arranged on one pillar 71 at a predetermined pitch, and a plurality of light receiving elements 74 made of phototransistors, photodiodes, etc. are arranged on the other pillar 72. Are arranged at a predetermined pitch so as to face each of the light projecting elements 73 ,.
The height of the product 63, that is, the height of the bar code surface is measured depending on the height of the light-projecting element 73 at which the light from is blocked by the product 63. The imaging cameras 27 and 47 and the barcode scanners 28 and 48 are
They are arranged as shown in FIG. The imaging camera 27,
47 is the image input area 7 of the belt conveyors 23 and 43.
It is arranged above the image pickup device 5, and the product passing through the image input area 75 is imaged, and the position and the inclination of the barcode are detected from the image.

The bar code scanners 28 and 48 are adapted to read bar codes from products passing through the scanning areas 76 of the belt conveyors 23 and 43.
That is, the bar code scanners 28 and 48 are the same as those shown in FIG.
As shown in FIG. 3, a semiconductor laser 81 is provided as a light source, and the laser light emitted from the bonding surface of the semiconductor laser 81 is collimated by a collimator lens 82, a beam expander 83, a variable focus optical system 84 constituting a focus automatic adjusting means, The galvanometer mirror 8 is sequentially inserted through the hole formed in the center of the mirror 85.
Irradiates 6,87.

As shown in FIG. 7, the beam expander 83 is composed of, for example, two prisms 83a and 83b, and is adapted to correct the beam diameter of the laser light which is collimated by the collimator lens 82. There is. The variable focus optical system 84 is provided with a focus lens movably in the optical axis direction.
It moves at 8 to automatically adjust the focal length. An actuator such as a voice coil may be used instead of the focus motor 88. The galvano mirrors 86 and 87 are for deflecting the laser light and converting it into scanning light. The galvano mirror 86 controls the x direction, the galvano mirror 87 controls the y direction, and both scan the scanning direction of the scanning light. x, y direction, that is, the belt conveyor 2
It can be changed in any direction on a plane parallel to 3, 43.

Scanning light from the Galvano mirrors 86 and 87 scans a surface parallel to the belt conveyors 23 and 43, that is, a bar code surface attached to the upper surface of the product 63. Then, the scattered reflection light generated when the scanning light scans the barcode surface is reflected by the condenser mirror 85 via the galvano mirrors 87 and 86, and further the lens 8 is used.
Video sensor 9 including a photodiode through 9
It receives light at 0. Then, the output of the video sensor 90 is decoded and output to the POS terminal 67.

With this structure, the bar code scanners 28 and 48 can change the focal length and the scanning direction, and the focus motor 88 is driven by the height measurement information from the height measuring devices 26 and 46. The focus lens of the variable focus optical system 84 is moved and controlled to automatically adjust the focal length, and the galvano mirror 8 is adjusted based on the bar code position and tilt information from the imaging cameras 27 and 47.
Drive control of 7, 86 is performed so that the scanning direction of the scanning light is properly read.

As shown in FIG. 5, the controller 91 is
Belt conveyors 23, 43, height measuring devices 26, 4
6, the imaging cameras 27 and 47, the focus motor 88, the galvanometer mirrors 86 and 87, and the video sensor 90 are controlled. That is, the controller 91
Drives the driver 92 to drive the belt conveyor 23,
The conveyor motor 93 for driving 43 is driven, the driver 94 is driven to drive the focus motor 88, and the driver 95 is driven to drive the galvanometer mirror 8.
6 and 87 are drive-controlled. In addition, the controller 91
Drives the height measuring devices 26, 46 to fetch the height measuring information from the height measuring devices 26, 46, drives the image processor 96 to fetch the image information from the imaging cameras 27, 47, and the decoder 97. Is driven to fetch bar code information from the video sensor 90.

The POS terminal 67 performs control for merchandise registration. When the start buttons 31 and 51 are turned on, a start display is displayed on the guidance display 33 and 53 and the first counter is cleared. . Further, the controller 91 drives and controls the conveyor motor 93 to start the operation of the belt conveyors 23 and 43. Then, when the height measuring devices 26 and 46 detect the height of the product 63, the POS terminal 67 increments the first counter.

The controller 91 is a height measuring device 2
6, 46 and the information from the imaging cameras 27, 47 detect the height of the barcode surface, the position and the inclination of the barcode, and the barcode scanner 2 based on the detected information.
8, 48 focus motor 88 and galvanometer mirror 8
6, 87 drive control, barcode scanner 28, 48
The focal length of the scanning light from is determined on the bar code surface of the product 63, and the scanning direction of this scanning light is determined so as to scan the bar code surface correctly. And the video sensor 9
The signal from 0 is decoded and supplied as bar code information to the POS terminal 67.

The POS terminal 67 has a controller 91.
The bar code information is fetched from the above, collated with the database, and if there is a matching product, the product data is registered and the second counter is incremented. The registered merchandise is conveyed to the registered merchandise stackers 29 and 49 as the registered merchandise 63a.

Further, when a product matching the decoded bar code information cannot be detected from the database,
To that effect, the operator 65 is informed by, for example, a lamp display or the like, and the product is conveyed to the unregistered product stacker 64. The operator 65 uses the register 66 to register the products conveyed to the unregistered product stacker 64. The second counter is also incremented when this product registration is performed. The registered product at this time is returned to the belt conveyors 23 and 43 to register the registered product 63a.
Will be conveyed to the registered product stackers 29 and 49.

Such product registration work is repeated until the customer operates the end buttons 32 and 52. When the customer operates the end buttons 32 and 52, the value of the first counter is held in the memory. The held value is compared with the value of the second counter, and if they match, it is determined that all the products have passed and registration is completed, and the total sum of the customers is displayed on the subtotal indicators 30 and 50. Clear the counter. In addition, the image processor 96 uses the image pickup camera 2
Image processing based on the flowchart shown in FIG. 6 is performed based on the image information from 7, 47.

That is, in S1, the image of the article area including the bar code is extracted from the input image. Then, in S2, the extracted article image is converted into binary data and stored in the memory. Subsequently, in S3, enlargement / reduction is performed to create a connected region of black pixels, and a connected region composed of a predetermined number or more of black pixels is extracted. Subsequently, in S4, the feature amount of the shape for each connected region is obtained.

Subsequently, in S5, a logical product of the connected area and the binary data is obtained, and a figure in which a predetermined number or more of black pixels are continuous is extracted. Subsequently, in S6, the direction of inclination of the figure is obtained, and the number of figures is aggregated for each connected region for each predetermined direction. Then, in S7, the feature amount of the shape of the connected area and the number of distinct directions of the figure are compared for each connected area. Then, finally, in S8, a connected area having a rectangular shape and a large number of figures in the same direction is detected as a barcode area. In this way, the position and the inclination of the barcode will be detected.

FIG. 8 shows the bar code scanners 28 and 4 described above.
8 is a schematic view when the optical system in which the collimator lens 82 and the beam expander 83 are omitted is replaced with one lens 100, and spreads in the direction perpendicular to the bonding surface of the semiconductor laser 81 as described in FIG. Laser light 1
The light emitting point P1 of 01 is closer to the emitting end face of the laser light than the light emitting point P2 of the laser light 102 spreading in the direction parallel to the joint surface. When this is imaged by the same lens 100, the distance to the image formation point of the laser light 101 spreading in the direction perpendicular to the cemented surface, that is, the focal length Lv, is the result of the laser light 102 spreading in the direction parallel to the cemented surface. The distance to the image point, ie
It becomes longer than the focal length Lh.

Therefore, for example, when the bonding surface of the semiconductor laser 81 is parallel to the surfaces of the belt conveyors 23 and 43, the distance to the bar code surface on the product 63 is L.
If it is h, if the bar direction of the bar code is the conveying direction of the belt conveyors 23 and 43, the scanning light direction is the width direction of the belt conveyors 23 and 43. Scanning is performed in a direction parallel to the bonding surface of the semiconductor laser 81. Therefore, in this case, since the scanning light focuses on the bar code surface, the bar code can be reliably read and decoded.

On the other hand, if the bar direction of the bar code is the width direction of the belt conveyors 23 and 43, the scanning light direction is the conveying direction of the belt conveyors 23 and 43. Scan in the direction perpendicular to the bonding surface of the semiconductor laser 81. Therefore, in this case, the distance at which the scanning light is focused becomes Lv, and the light beam that cannot be fully stopped hits the bar code surface, so that the bar code cannot be reliably read and decoded.
Therefore, when the bar direction of the bar code is the width direction of the belt conveyors 23 and 43, the controller 91 drives and controls the focus motor 88 to move and scan the focus lens of the variable focus optical system 84. Adjust so that the light is focused at the distance Lh.

That is, the controller 91 causes the scanning direction of the scanning light with respect to the direction of the bonding surface of the semiconductor laser 81 to be a predetermined angle set between a surface parallel to the bonding surface and a surface perpendicular to the bonding surface. , At 45 degrees,
When the scanning direction of the scanning light is inclined to the plane parallel to the 45 degrees, the movement of the focus lens with respect to the distance to the bar code surface is controlled based on the graph g1 in FIG. When the scanning direction of the scanning light is inclined to the surface side, the movement control of the focus lens with respect to the distance to the bar code surface is performed based on the graph g2 in FIG. That is, the automatic adjustment characteristic is changed according to the inclination of the scanning light in the scanning direction. Graph g2 is graph g
It is a graph that 1 is moved horizontally.

By making the automatic adjustment characteristics different in this way, when the scanning direction of the scanning light on the bar code surface is within 45 degrees with respect to the width direction of the belt conveyors 23 and 43, the focus lens is used. Movement control of graph g
The scanning direction of the scanning light is between 45 degrees and 90 degrees (conveying direction of the belt conveyors 23 and 43) with respect to the width direction of the belt conveyors 23 and 43. In this case, the movement control of the focus lens is performed based on the graph g2, and the focus of the scanning light is controlled by the bar regardless of the scanning direction of the scanning light on the surface of the belt conveyors 23, 43. It can be aligned on the code surface, so that the barcode can be reliably read and decoded.

In this embodiment, an angle of 45 degrees is set between the plane parallel to the joint surface of the semiconductor laser and the plane perpendicular to this joint surface. When the scanning direction of the scanning light is inclined to the parallel plane side, the movement control of the focus lens with respect to the distance to the bar code surface, that is, the automatic focus adjustment is performed according to the graph g1. When the scanning direction of the scanning light is inclined, the focus is automatically adjusted according to the graph g2, but the present invention is not limited to this. A plane parallel to the bonding surface of the semiconductor laser and a surface perpendicular to this bonding surface are used. Two angles, 30 degrees and 60 degrees, are set between them, and when the scanning direction of the scanning light is inclined to the parallel plane side more than 30 degrees, the focus is automatically adjusted according to the graph g1. while When there is the scanning direction of the scanning light, the focus is automatically adjusted according to the graph g3 shown by the dotted line in FIG. 9, and when the scanning direction of the scanning light is inclined to the vertical surface side more than 60 degrees, the focus is automatically adjusted according to the graph g2. It may be performed. By doing so, the automatic adjustment of the focus with respect to the inclination becomes more accurate, and the barcode can be more reliably read and decoded.

Further, in this embodiment, the inclination of the bar code is detected from the image obtained by the image pickup camera, the scanning direction of the scanning light is changed according to the inclination, and the scanning direction of the scanning light is changed. The automatic focus adjustment characteristics of the varifocal optical system were changed by changing the bar code attached to the product (article) conveyed on the belt conveyor, for example, in the case where the same direction continues. The focus automatic adjustment characteristic used by the variable focus optical system may be determined in advance by key input or the like in accordance with the orientation of. This is because, for example, in the field of physical distribution, the same product may be attached with a barcode label in the same direction and conveyed. In such a case, the automatic focus adjustment used by the varifocal optical system depends on the orientation of the barcode. The adjustment characteristic can be determined in advance by key input or the like. If the sticking direction of the bar code label changes when handling another item, the key focus may be input again to change the automatic focus adjustment characteristic used by the variable focus optical system. .

Further, in this embodiment, the height detecting means has been described by arranging a plurality of pairs of the light emitting element and the light receiving element, but the present invention is not necessarily limited to this, and the reflection of ultrasonic waves is not limited to this. To detect height using
It is also possible to use one that mechanically contacts the probe, one that detects the height by image processing using the light section method, or the like.
Further, when articles of the same height are continuously conveyed, height information may be manually input such as by key input.

Further, in this embodiment, the focus lens of the variable focus optical system is controlled to move to automatically adjust the focal length, but the present invention is not limited to this, and the optical path can be changed without changing the focal length. It is also possible to change the focal length by changing the shape of the lens such as a length changing element or an acousto-optic element. In addition, although this embodiment has described the present invention applied to a checkout system for automatically registering goods, the present invention is not necessarily limited to this, and can be applied to general physical distribution systems that convey articles by a belt conveyor or the like. .

[0036]

As described above, according to the first and third aspects of the present invention, whether the scanning direction of the laser light emitted from the semiconductor laser is on the parallel surface side or the vertical surface side with respect to the bonding surface of the semiconductor laser. The focal length can be made to match the distance from the barcode surface regardless of whether the scanning direction of the laser beam is on the parallel surface side or the vertical surface side by making the automatic focus adjustment characteristics different. Accurate automatic focus adjustment control is always possible, and barcode reading can be performed reliably.

According to the second or third aspect of the present invention, when the scanning direction of the laser light emitted from the semiconductor laser can be automatically changed based on the position and the inclination of the bar code, the scanning direction of the laser light. By changing the automatic focus adjustment characteristics depending on whether the laser beam is on the parallel surface side or the vertical surface side with respect to the bonding surface of the semiconductor laser, even if the laser beam scanning direction is on the parallel surface side, Even if there is, the focal length can be matched with the distance to the bar code surface, which allows accurate automatic focus adjustment control and reliable bar code reading.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a checkout system showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a height measuring device according to the same embodiment.

FIG. 3 is a perspective view showing an arrangement relationship of a height measuring device, an imaging camera and a barcode scanner according to the same embodiment.

FIG. 4 is a diagram showing a configuration of a variable scanning optical system bar code scanner according to the same embodiment.

FIG. 5 is a block diagram of main parts in the same embodiment.

FIG. 6 is a flowchart showing a barcode area detection process in the embodiment.

FIG. 7 is a diagram showing a configuration of a beam expander according to the same embodiment.

FIG. 8 shows a relationship between a light emitting point and a focal length of laser light spreading in a direction perpendicular to the bonding surface of the semiconductor laser and a light emitting point and a focal length of laser light spreading in a direction parallel to the bonding surface in the same embodiment. Fig.

FIG. 9 is a graph for explaining a change in the automatic adjustment characteristic corresponding to the inclination of the scanning light in the scanning direction in the same embodiment.

FIG. 10 is a perspective view showing a conventional example.

FIG. 11 is a perspective view for explaining emission characteristics of a semiconductor laser.

[Explanation of symbols]

 23, 43 ... Belt conveyor 26, 46 ... Height measuring device 27, 47 ... Imaging camera 28, 48 ... Variable scanning optical system bar code scanner 81 ... Semiconductor laser 84 ... Variable focus optical system 86, 87 ... Galvano mirror 88 ... Focus Motor 91 ... Controller

Claims (3)

[Claims] 1. An article carrying means for carrying an article with a bar code, a semiconductor laser, and scanning light for converging and deflecting laser light from the semiconductor laser to scan the bar code surface of the article. A scanning optical mechanism for converting, a focus automatic adjusting means provided inside the scanning optical mechanism for automatically adjusting the focus of scanning light according to the distance to the barcode surface of the article, and scanning light for the barcode surface of the article. And a bar code reading means for receiving a reflected light when scanning and reading a bar code, wherein the scanning direction of the scanning light with respect to the direction of the joint surface of the semiconductor laser is parallel to the joint surface. Depending on whether it is on the parallel surface side or the vertical surface side with a predetermined angle set between it and the surface perpendicular to this joining surface as a boundary,
A code reading device characterized in that the focal lengths are made to coincide by varying the automatic adjustment characteristics of the automatic focus adjustment means. 2. An article carrying means for carrying a bar coded article, a height detecting means for detecting a height of a bar code surface of an article carried by the article carrying means, and a article carrying means for carrying the article. Position and tilt detecting means for imaging the bar code surface of an article to detect the position and tilt of the bar code, a semiconductor laser, and a laser beam from the semiconductor laser for converging and deflecting the bar code surface of the article. Is converted into scanning light for scanning, and the scanning direction of the scanning light is changed so as to correctly scan the barcode surface of the article based on the information on the position and the inclination of the barcode from the position and inclination detecting means. Scanning optical mechanism and a focus automatic adjusting hand which is provided in the scanning optical mechanism and automatically adjusts the focus of the scanning light based on the height detection information of the bar code surface from the height detecting means. A step, and a bar code reading means for receiving a reflected light when the bar code surface of the article is scanned by the scanning light to read the bar code, the scanning light of the scanning light in the direction of the bonding surface of the semiconductor laser. Scan direction is
The automatic adjustment characteristic of the automatic focus adjustment means depends on whether the surface is parallel or vertical with respect to a predetermined angle set between the surface parallel to the joint surface and the surface perpendicular to the joint surface. The code reading device is characterized in that the focal lengths are made to coincide with each other. 3. A predetermined angle is set to 45 degrees, and the automatic adjustment characteristic of the automatic focus adjustment means is changed depending on whether the scanning direction of the scanning light is on the parallel surface side or the vertical surface side with this angle as a boundary. The code reader according to claim 1 or 2, characterized in that.