JPH0896063A - Comodity information reader - Google Patents

Abstract

PURPOSE: To improve the reading accuracy of the bar code imparted to a comodity without providing many bar code scanners when the bar code imparted to the comodity is read in the process of the carrying the comodity. CONSTITUTION: The location of the bar code la imparted to a comodity 1 is detected from the image of the comodity 1 photographed by video cameras 7a and 7b. From the detection result, the locations of bar code scanners 8a to 8d are set to proper reading locations. Thus, the locations of the bar code scanners 8a to 8d are set to the proper reading locations according to the comodity 1 and the bar code 1a imparted to the comodity 1, the bar code 1a can be read with accuracy by a small number of the bar code scanners 8a to 8d, and the reading accuracy of the bar code 1a can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a merchandise information reader for automatically carrying merchandise bearing a bar code and reading the bar code information in the process.

[0002]

2. Description of the Related Art Conventionally, there is a product information reading apparatus which conveys a product from a product carry-in position to a product discharge position by using a belt conveyor or the like, and a bar code scanner reads a bar code attached to the product in the process. is there. In such a device, the barcode information attached to the products can be read by simply placing the products one after another at the product carry-in position, so that the work of inputting the product information by reading the barcode is unmanned. The input work of such product information occupies most of the work items in the product registration work at the cash register and the POS terminal. Therefore, by using the product information reading device, the product registration work can be rationalized.

[0003]

In the merchandise information reading device, merchandise is randomly placed at the merchandise carry-in position. For this reason, it is not specified at what position and at what angle the barcode is attached to the conveyed product. Therefore, in such a product information reading apparatus, it is necessary to prepare many bar code scanners and install the respective bar code scanners by changing their reading directions and angles. For this reason, a large number of bar code scanners, for example, at least eight bar code scanners are required, which has the disadvantage of increasing the product cost. Moreover, no matter how many bar code scanners are prepared, it is impossible to cover all the bar code positions passing through the product passing area, so it is impossible to improve the bar code reading accuracy to some extent. It also has drawbacks.

Further, the height of the products varies from product to product. Therefore, it is necessary to secure a certain distance between the belt conveyor and the bar code scanner in order to prevent the passage of tall products. On the other hand, the reading depth of the barcode scanner is 110-15.
It is about 0 mm, and if the reading depth is out of this range, proper reading cannot be performed. Therefore, there is a drawback that the barcode reading accuracy is low due to the reading depth of the barcode scanner.

In order to prevent a decrease in reading accuracy due to the problem of the reading depth of the bar code scanner, the height of the product is detected and the height of the bar code scanner is changed according to the detection result. A product information reading device has been proposed. In such a product information reading device, a plurality of optical sensors are arranged vertically in the passing area of the product, and the height of the product can be determined by observing which height of the optical sensors reacts when the product passes. It is detecting. However, the device with such a structure merely changes the height of the bar code scanner according to the height of the product, and the bar code corresponding to all the bar code positions passing through the product passing area. It does not allow reading. Therefore, the problem that the reading accuracy of the barcode cannot be increased to a certain extent or more cannot be solved.

[0006]

According to the present invention, there is provided a carrying section for carrying a product from a product carry-in position to a product discharge position via a product information reading position, and a video camera for photographing the product placed at the product carry-in position. , Bar code position determining means for determining the position of the bar code attached to the product based on the image captured by the video camera, and bar code information movably provided in at least the two-dimensional direction at the product information reading position. It is configured to include a bar code scanner for reading and a position setting means for setting the position of the bar code scanner to an appropriate reading position based on the position of the bar code judged by the bar code position judging means.

[0007]

When the product is carried from the product carry-in position to the product discharge position by the carrying section, the product placed at the product carry-in position is photographed by the video camera, and the bar code attached to the product based on the photographed image. The position of is determined by the barcode position determination means. Then, based on the determination result, the bar code scanner is moved in at least the two-dimensional direction by the position setting means, and the position of the bar code scanner is set to an appropriate reading position. Therefore, by reading the information of the bar code attached to the product by the bar code scanner positioned at the proper reading position, the bar code reading accuracy can be improved. Moreover, many bar code scanners are not required.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the overall structure of the device. A conveyance path 2 for the product 1 from the product carry-in position I through the product information reading position R to the product discharge position O is formed. This transport path 2 is
It is formed by a carry-in conveyor 3 as a carrying unit arranged at a product carry-in position I, a carry-out conveyor 4 as a carrying unit arranged at a product information reading position R, and a stocker 5 arranged at a product discharge position O. There is. The carry-out conveyor 4 arranged at the product information reading position R is covered with a cover 6. The inlet 6a of the cover 6 communicates with the product carry-in position I, and the outlet 6b communicates with the product discharge position O.

Next, as shown in FIGS. 1 and 3, two video cameras 7 for photographing the space at the product carry-in position I are provided. One video camera 7a is arranged at the end of the product carry-in position I, and the other video camera 7b is arranged inside the cover 6 near the entrance 6a. Here, the relationship between each surface of the product 1 illustrated in FIG. 2 and the shooting surface of the product 1 by the two video cameras 7 will be described. Figure 2
Except for the bottom surface, the product 1 illustrated in 1. has five planes, namely, a plane A, a traveling direction front surface B, a traveling direction back surface C, a traveling direction left side surface D, and a traveling direction right side surface E. In FIG. 2, the traveling direction is indicated by an arrow. The one video camera 7 is set so that the C and E surfaces of the product 1 can be photographed. The other video camera 7 is set so that the A, B and D surfaces of the product 1 can be photographed.

At the product information reading position R, four bar code scanners 8 for reading the information of the bar code 1a attached to the product 1 are provided. These bar code scanners 8 are AB surface scanners 8a for reading information of the bar codes 1a attached to the A and B surfaces of the product 1 illustrated in FIG.
Read the information of the barcode 1a attached to the A and C surfaces A
C-side scanner 8b and bar code 1 attached to B and D sides
The BD surface scanner 8c reads the information of a and the CE surface scanner 8d reads the information of the barcode 1a attached to the C and E surfaces. Here, for convenience of description, the horizontal direction that is the same as the conveyance direction of the product 1 is the X direction, the horizontal direction orthogonal to this is the Y direction, and the vertical direction is the Z direction. The AB surface scanner 8a and the AC surface scanner 8b are integrally formed, and as shown in FIG. 4, mounted on a horizontal rail 10 slidably mounted on a vertical rail 9 in the Z direction so as to be slidable in the Y direction. There is. Therefore, these AB surface scanner 8a and AC surface scanner 8b are
Free to move in any direction. In addition, as shown in FIG.
The surface scanner 8c is arranged on the left side in the traveling direction, and the CE surface scanner 8d is arranged on the right side in the traveling direction. Then, these BD surface scanner 8c and CE surface scanner 8d are
As shown in FIG. 5, it is slidably mounted in the Z direction on a vertical rail 12 mounted slidably in the Y direction on a horizontal rail 11. Therefore, these B
The D surface scanner 8c and the CE surface scanner 8d are also movable in the Y and Z directions. In other words, when viewed as a whole bar code scanner 8, this bar code scanner 8 has Y, Z
It is movably supported in the two-dimensional direction which is the direction.

Next, a plurality of sensors 1 for detecting the position of the product 1 in the transport path 2 are provided in the transport path 2.
3 to 16 are provided. These sensors 13-16
Is a reflection type optical sensor. These sensors 13-1
Details of No. 6 will be described below. First, at the product carry-in position I, the presence or absence of the product 1 placed on the carry-in conveyor 3,
A product detection sensor 13 that detects the width and the position in the Y direction is arranged. As illustrated in FIGS. 1 and 3, the product detection sensor 13 has a structure in which a plurality of optical sensors 13a having a light irradiation direction in the X direction are arranged in a line in the Y direction at regular intervals. Next, at the product information reading position R, the carry-in sensor 14 is arranged at the entrance 6a of the cover 6. The carry-in sensor 14 is a sensor for detecting the height of a product carried in to the product information reading position R, and includes a plurality of optical sensors 1 having a light irradiation direction in the Y direction.
This is a structure in which 4a are arranged in a line in the Z direction at regular intervals. Next, at the product information reading position R, a position sensor 15 is arranged immediately before the reading position of the barcode 1a by the barcode scanner 8. The position sensor 15 has a light irradiation direction in the Y direction and detects the presence or absence of the product 1. Then, at the product information reading position R,
A discharge sensor 16 is arranged immediately before the outlet 6b of the cover 6. The discharge sensor 16 has a light irradiation direction in the Y direction and detects the presence or absence of the product 1.

The electrical connection of each part will be described below. As shown in the block diagram of FIG. 6, a CP that centrally controls each unit.
Fixed data such as operation programs is fixedly stored in the ROM 18 connected to the U 17, and variable data is rewritably stored in the RAM 19. Further, an image processing CPU 22 to which a unique ROM 20 and RAM 21 are connected is provided for the video camera 7, and this image processing CPU
22 is also connected to the CPU 17. The bar code scanner 8 and various sensors 13 to 16 are also connected to the CPU 17 via an input circuit (not shown). Further, a conveyor motor 23 for driving the carry-in conveyor 3 and the carry-out conveyor 4 and a scanner motor 24 for selectively moving the barcode scanner 8 in the Y or Z direction are provided, and both are provided to the CPU 17. It is connected. Further, a transmission control circuit 2 for connecting the commodity information reading device of this embodiment to a POS terminal or the like not shown.
5, the transmission control circuit 25 is also connected to the CPU 17. The CPU is connected to each unit through a system bus such as an address bus, a data bus, and a control bus.

Next, the commodity information reading apparatus of this embodiment is provided with a bar code position determining means and a position setting means. The barcode position determination means performs image processing based on the image captured by the video camera 7 under the control of the image processing CPU 22 according to the operation program stored in the ROM 20, and determines the position of the barcode 1a attached to the product 1. Is a means to do. The position setting means drives the scanner motor 24 based on the position of the barcode 1a determined by the barcode position determining means under the control of the CPU 17 according to the operation program stored in the ROM 18,
This is means for setting the position of the barcode scanner 8 to an appropriate reading position.

In such a structure, the outline of the processing flow is as follows: when the product 1 is placed on the carry-in conveyor 3.
The product 1 is transported on the transport path 2 and discharged to the stocker 5. In the process, the barcode 1a attached to the product 1 is read by the barcode scanner 8 and the product information is input. At this time, the product 1 is photographed by the video camera 7, and the positions of the product 1 and the barcode 1a are determined by the barcode position determination means. Then, based on the determination result, the position of the barcode scanner 8 is set to an appropriate reading position by the position setting means, and the barcode 1a
Reading accuracy is improved.

Details of the flow of such processing will be described with reference to the flowchart of FIG. First, carry-in conveyor 3
When the product 1 is placed on the product, the product detection sensor 13 is turned on (step S1), and it is detected that the product 1 is placed at the product carry-in position I. In the subsequent step S2, the approximate width and position of the product 1 are determined from the output of the product detection sensor 13, and in step S3, the scanner motor 24 is driven based on the determination result and each of the bar code scanners 8a to 8d is turned Y. Move in the axial direction. The movement of the barcode scanner 8 here is performed by the commodity 1 conveyed on the conveyance path 2.
The main purpose is to prevent interference with. Therefore, it is not strictly performed. Then, after an image processing command is issued (step S4), the conveyor motor 23 is driven and the carry-in conveyor 3 is started (step S5). The image processing command in step S4 is issued to the image processing CPU 22. The image processing CPU 22 that has received the image processing command executes the barcode 1a determining means. That is, the position of the barcode 1a attached to the product 1 is determined by the image processing technique. Details of the processing will be described later based on the flowchart of FIG.

Then, the commodity 1 is conveyed by the start of the carry-in conveyor 3, and the carry-in sensor 14 is turned on by the conveyed commodity 1 (step S6). Then, the carry-in conveyor 3 is stopped after a predetermined time has elapsed (step S
7), the conveyor motor 23 is driven and the carry-out conveyor 4
Starts (step S8). The predetermined time from when the carry-in sensor 14 is turned on until the carry-in conveyor 3 is stopped is the time required to deliver the product 1 from the carry-in conveyor 3 to the carry-out conveyor 4. At this time, the height of the product 1 is determined from the output of the carry-in sensor 14 (step S9). Then, the scanner motor 24 is driven based on the determination result, and the bar code scanners 8a to 8d move in the Z-axis direction (step S10). Similar to step S3, the movement of the barcode scanner 8 is performed mainly for the purpose of preventing interference with the product 1 conveyed on the conveyance path 2, and is not strictly performed.

The processing up to step S10 is C
While being executed by the PU 17, the image processing CPU 22
Thus, the position determination process of the barcode 1a attached to the product 1 is executed. Therefore, in the subsequent step S11, the determination result of the position of the barcode 1a executed by the image processing CPU 22 is called, and in step S12 the positions of the barcode scanners 8a to 8d are adjusted based on the determination result. That is, the scanner motor 24 is driven to adjust the bar code scanners 8a to 8d in the Y and Z directions. Since the adjustment of the bar code scanner 8 here is strictly performed according to the position of the detected bar code 1a, each bar code scanner 8a to 8d is correctly set to an appropriate reading position according to their reading depth and the like. Is set. The position setting means is executed by the processing in steps S11 and S12.

When the discharge sensor 15 is turned on by the product 1 conveyed to the carry-out conveyor 4 (step S1)
3), the carry-out conveyor 4 is stopped (step S1)
4). As a result, the product 1 is temporarily stopped before the position where the barcode scanner 8 reads the barcode 1a. At this time, if the position adjustment of the barcode scanner 8 is completed (step S15), the carry-out conveyor 4 is restarted (step S16), and the barcode scanner 8 reads the barcode 1a (step S17). ). In the case of the product 1 illustrated in FIG. 2, the barcode 1a attached to the A surface of the product is the AB surface scanner 8
a and the AC surface scanner 8b, the bar code 1a attached to the B surface is the AB surface scanner 8a and the BD.
The barcode 1a read by the surface scanner 8c and attached to the C surface is read by the AC surface scanner 8b and the CE surface scanner 8d, and the barcode 1 attached to the D surface.
a is read by the BD surface scanner 8c, and the barcode 1a attached to the E surface is read by the CE surface scanner 8d. To read such a barcode 1a,
Since the bar code scanner 8 is properly set to the proper reading position by the position setting means executed by the processing of step S11 and step S12, it is performed accurately.

Thereafter, when the discharge sensor 16 is turned on by the passage of the product 1 (step S18), the bar code 1
at least one bar code scanner 8 for reading a
It is determined whether or not two conditions, that is, whether all the read data are the same (step S20) have been satisfied. If all of the conditions are satisfied, the carry-out conveyor 4 is stopped after the lapse of a predetermined time (step S21), and the product 1 is discharged to the stocker 5 located at the product discharge position O. On the other hand, if only one of the conditions is not satisfied, the carry-out conveyor 4 is stopped (step S22), and the returning process of the product 1 is executed (step S23). This product return process is a process in which the carry-out conveyor 4 and the carry-in conveyor 3 are reversely rotated to return the product 1 to the product carry-in position I.

Here, the image processing CPU 22 which has received the image processing command in step S4 executes the position determining process of the barcode 1a shown in FIG. 8, that is, the barcode position determining means. This process consists of three steps: detection of moving articles, extraction of bar candidates, and bar code area determination.

The moving article detection process will be described. First, an image of the product carry-in position I in a state where nothing is placed on the carry-in conveyor 3 is photographed by the video camera 7,
It is stored in the RAM 21 as a 256-gradation background image. Then, when the image processing CPU 22 receives the image processing command, the image of the product carry-in position I is captured by the video camera 7 and stored in the RAM 21 as an input image of 256 gradations (step S31). Then, a two-gradation difference image in which a pixel having a difference value between the input image and the background image is a threshold value or more is set as a target pixel is created (step S3).
2). As the threshold value, for example, the difference is 48 gradations between the input image and the background image. Then, in order to smooth the concave portions existing in the difference image created in this way and to fill the small holes (holes), after enlarging / reducing, for example, about three times (step S33), the difference image and the input image are combined. The logical operation is performed between the two to obtain a moving article image having 256 gradations (step S34).

The extraction process of bar candidates will be described. The bar candidate extraction process is a process of extracting the barcode 1a candidate. First, a binarization threshold value calculation process is performed (step S35). In this process, the luminance (gradation) histogram of the moving article image is obtained, and the one with lower luminance (dark side)
Is a process of extracting bar candidates with a luminance value whose cumulative distribution from 1 is 1% of the total (P-tile method, automation of threshold setting). The bar candidates thus extracted are binarized bar candidates (step S36).
Therefore, even if the barcode 1a is not black, if the brightness is low, it is extracted as a candidate. At this stage,
Figures and characters other than the barcode 1a are also extracted as bar candidates.

The bar code area determination processing will be described. The binarized bar candidates are subjected to a thinning process, that is, a process of thinning a line figure into a core having a width of 1, and labeling is performed for each line (step S37). And
A fractional point is obtained for each label, a thin line having two fractional points is set as a new bar candidate, and the inclination of each bar candidate is obtained from the coordinate value of this endpoint (step S38). The inclination of the bar candidate is obtained as an angle θ (−90 <θ ≦ 90) with respect to the x-axis, as illustrated in FIG. In the following step S39, quantization is performed by rounding off the last digit of the angle θ, and each line segment is grouped using the quantized θ value. Grouping is performed, for example, in 18 groups. From the characteristic of the barcode 1a that the bars in the same direction are gathered, the group having the largest number of bars forming the group is recognized as the final barcode 1a. Therefore, in step S40, the other groups, that is, false bars are eliminated, and step S4
At 1, the smallest rectangle surrounding all the bars of the corresponding group is determined as the barcode area.

Such steps S31 to S4
By the processing of 1, the position and the inclination θ of the barcode 1a are detected. Therefore, the bar code position determination means is executed by the processing of steps S31 to S41. Therefore, the barcode 1 detected in this way
Information on the position a and the inclination θ is stored in the RAM 21 and is a target to be called in step S11 shown in FIG.

As described above, according to this embodiment,
The barcode 1a can be accurately read by the small number of barcode scanners 8a to 8d, and the reading accuracy of the barcode 1a can be improved.

In the implementation, the number of bar code scanners 8 is not limited to four, and for example, only one bar code scanner 8 that is movable in the three-dimensional direction may be provided. .

[0027]

The present invention detects the position of a bar code attached to a product from an image of the product taken by a video camera,
Since the position of the bar code scanner is set to an appropriate reading position from the detection result, the position of the bar code scanner can be set according to the individual product and the bar code attached to the product. It is possible to improve the bar code reading accuracy without providing many bar code scanners.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is a perspective view of a product showing a shooting surface of the product shot by each video camera and a reading surface of the product read by each barcode scanner.

FIG. 3 is a plan view showing an arrangement state of video cameras.

4A and 4B show a mounting structure of an AB surface scanner and an AC surface scanner, FIG. 4A is a front view thereof, and FIG. 4B is a side view thereof.

5A and 5B show a mounting structure of a BD surface scanner and a CE surface scanner, FIG. 5A is a front view thereof, and FIG. 5B is a side view thereof.

FIG. 6 is a block diagram showing electrical connection of each unit.

FIG. 7 is a flowchart showing the flow of overall processing.

FIG. 8 is a flowchart showing the flow of image processing for determining the position of a barcode.

FIG. 9 is a conceptual diagram related to processing for obtaining a barcode angle.

[Explanation of symbols]

 1 Product 1a Barcode 3, 4 Conveyor 7 Video camera 8 Barcode scanner I Product carry-in position O Product discharge position R Product information reading position S11, S12 Position setting means S31 to S41 Barcode position determination means

Claims (1)

[Claims] 1. A transport unit for transporting a product from a product carry-in position to a product discharge position via a product information reading position, and a video camera for photographing the product placed at the product carry-in position.
Bar code position determining means for determining the position of the bar code attached to the product based on the image captured by the video camera, and bar code information movably provided at least in the two-dimensional direction at the product information reading position. Product information including a bar code scanner for reading and position setting means for setting the position of the bar code scanner to an appropriate reading position based on the position of the bar code judged by the bar code position judging means. Reader.