JP3397170B2 - Information code recording position detecting device and optical information reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a technique for reading an information code recorded on a moving article.

[0002]

2. Description of the Related Art Conventionally, as a method for optically reading an information code such as a bar code or a two-dimensional code, a light emitting means such as an LED emits light for reading the optical information to an optical information recording surface and is a light receiving element. CCD arrayed with photo sensors
A method is known in which a sensor is used to capture an information code as an image from the reflected light in a device and decode the image.

Among these types of optical information readers, there has been an apparatus for reading a moving information code, for example, an information code recorded on an article conveyed by a belt conveyor. In this case, at the timing when the information code recorded on the article just enters the field of view of the CCD sensor, light for reading optical information is emitted to expose the CCD sensor to capture the information code as an image.

[0004]

In order to read the information code recorded on such a moving object at an appropriate timing, the information code must be attached to a predetermined position of the object. If the recording position of the information code is deviated, for example, the information code may be out of the visual field of the CCD sensor and a part or the whole of the information code area may not be included in the captured image.

Therefore, it is desirable to be able to inspect whether or not the recorded information code is in a proper position after recording the information code on the article. However, conventionally, there is no device for inspecting whether or not the information code recorded on the above-mentioned article is attached to the appropriate position of the article.

The present invention has been made to solve the above-mentioned problems, and is for inspecting whether or not the information code recorded on a moving article is recorded at an appropriate position on the article. An object of the present invention is to provide an information code recording position detecting device and an optical information reading device having a recording position detecting function.

[0007]

In the information code recording position detecting apparatus according to claim 1, which is made in order to achieve the above-mentioned object, the article moving on the conveying path has a predetermined conveying path. The detection means detects that the position has been reached. For example, it is detected that an article conveyed by a belt conveyor has moved to a predetermined position on the belt conveyor. It is conceivable that this detecting means is configured using, for example, a photo sensor. For example, light incident on the photosensor may be blocked while the article is moving, or light may be incident on the photosensor due to reflection by the article, and detection may be performed based on a signal change of the photosensor. Further, it is conceivable that the detection means is configured by using a sensor that detects the special ink applied to the article. The special ink is so-called magnetic ink or ink that modulates and reflects light of a predetermined wavelength.
Such a special ink is applied to an article, and the detection means irradiates the special ink with light of a predetermined wavelength to detect the modulated reflected light.

When the detection means detects that the article has reached a predetermined position on the conveyance path, the image acquisition means acquires an image after a predetermined time has elapsed from the detection time. This predetermined time is the time for the article to move from the predetermined position to the position where the information code recorded at the proper position of the article enters the field of view of the CCD sensor, and is set in advance according to the transport speed of the transport device. The image capturing means is composed of, for example, a CCD sensor, receives the reflected light of the light emitted toward the code recording surface of the article by the light emitting means, and captures the information code as an image.

The position information calculating means calculates, based on the captured image, position information capable of specifying the existing area of the information code in the image. For example, if the information code area is a quadrilateral area, the four vertices of the quadrilateral are calculated as position information.

Then, the code recording position calculating means calculates the recording position of the information code with respect to the article at least in the conveying direction based on the position information. Here, the calculation of the recording position "at least in the transport direction" means that each article is transported so as not to cause a "shift" in the direction perpendicular to the transport direction, or the article in the direction perpendicular to the transport direction. When at least one of the edges of the image is included in the image, even in the direction perpendicular to the transport direction,
This is because the recording position of the information code can be calculated.

The present invention focuses on the fact that the image pickup area of an article is determined by capturing an image at a predetermined capture timing on the assumption that the transport speed of the article is constant. Therefore, an image is captured after a lapse of a predetermined time from the time when the article is detected, and position information capable of specifying the code area in the image is calculated, whereby the recording position of the information code on the article is calculated as the detection result.

By using the recording position detected by the recording position detecting device of the present invention, for example, the calculated recording position is displayed on a display device or the like, and the user confirms the recording position. The recording position can be inspected. By the way, it is conceivable to calculate the absolute position, which is the distance from the end of the article, as the recording position for the article. In addition, as described above, if the special ink is applied to the article and the detection means detects the article with the special ink, the relative position of the distance from the position where the special ink is applied is calculated. May be. Furthermore, if the predetermined position (appropriate position) of the information code is stored, it is possible to calculate the relative position of the distance from the proper position.

When the proper position of the information code is stored in this way, the code recording position determining means further determines the information based on the recording position calculated by the code recording position calculating means, as described in claim 2. It may be possible to determine whether or not the code is recorded at an appropriate position on the article. In this case, this determination result is the detection result.
That is, it is convenient for the user because it is automatically determined whether or not the information code is recorded at an appropriate position on the article.

When calculating the positional information such as the positions of the four vertices of the quadrilateral code area as described above,
For example, as shown in claim 3, it can be considered that the calculation is performed based on the positioning symbol included in the information code.
For example, a two-dimensional code such as a QR code often has a specific pattern called a positioning symbol so that its code area can be specified in an image. Therefore, by using this positioning symbol, the above-mentioned position information can be easily calculated.

As the position information, it is possible to adopt the positions of the four vertices of the quadrilateral code area as described above, but the position information is not limited to this. For example, since the size of the code area can be known by detecting the positioning symbol, the position of at least one of the four vertices may be used as the position information. Further, for example, in the case of a QR code, it is conceivable that the central coordinates of the positioning symbol of the QR code are used as the position information as described in claim 4.

The QR code has three positioning symbols called a finder pattern. And
The center coordinates of the positioning symbol can be easily calculated as compared with the case of calculating the four vertex positions that specify the code area. Therefore, it is advantageous in that the calculation process of the position information is further simplified.

By the way, it is assumed that the direction of the articles conveyed on the conveyance path is not constant. For example, when a rectangular or rectangular parallelepiped shaped article is conveyed in the longitudinal direction, there is no distinction between the front and back of the shape of the article. Therefore, the article may be rotated by 180 degrees about the axis perpendicular to the code recording surface. Conceivable. Therefore, the direction of the information code may not be constant when the code recording surface is imaged. That is, the information code is, for example, 90 degrees, 180
It is considered that the image is captured in the image in a rotated state like degrees.

Therefore, as described in claim 5, further,
It is advisable to adopt a configuration including orientation determining means. The orientation determining means determines the orientation of the information code in the image based on the positioning symbol included in the information code. For example, Q
Taking the R code as an example, the above three positioning symbols are provided at the upper left, lower left, and upper right of the code area. Therefore, the orientation of the code can be determined from the arrangement of the positioning symbols. Then, at this time, the code recording position calculating means calculates the recording position of the information code according to the judgment result by the orientation judging means. As a result, the recording position of the information code can be appropriately calculated even when the orientation of the article conveyed on the conveyance path is not constant.

The image capturing means may capture a plurality of images. For example, it is conceivable to adopt the configuration shown in claim 6. That is, in this configuration, a plurality of different times are set as the predetermined time, and the image capturing means captures a plurality of images for one article at a plurality of time points. Then, the position information calculation means calculates the position information for each of the plurality of images, and the code recording position calculation means determines the recording position of the information code based on the position information calculated for each of the plurality of images. calculate.

By adopting such a configuration, it is possible to deal with the case where there are a plurality of information codes recorded on the article. That is, if the position information of another information code is obtained from a plurality of images, the recording position of each information code can be calculated. In such a configuration that captures multiple images,
Assuming that a plurality of information codes are recorded on the article, the code recording position calculating means may calculate a relative position with respect to a specific information code as a recording position, as set forth in claim 7. Good.

In the above description, it is assumed that the moving speed (conveying speed) of the article is constant, but even if the conveying apparatuses have the same specifications, the conveying speed may vary. . Further, the transportation speed may change due to aging. Therefore, it is conceivable to adopt the configuration described in claim 8. This configuration is premised on setting a predetermined time so that position information for the same information code is calculated from each of a plurality of images,
It is characterized in that the code recording position calculating means calculates the recording position in consideration of the conveyance speed of the article that can be calculated based on the position information for the same information code.

In this case, the predetermined time may be set so that images are acquired at relatively short intervals in consideration of the assumed conveyance speed of the article and the area of the code recording surface. If the image acquisition interval is shortened, the position information of the same information code can be obtained from a plurality of images. Then, based on this position information, the moving speed of the information code, that is, the conveying speed of the article is known. Therefore, the accurate recording position of the information code can be calculated based on this transport speed. As a result, there is an excellent effect that an accurate recording position of the information code can be calculated even if the transport speed varies or changes over time.

Although the invention of the recording position detecting device for the information code has been described above, as described in claim 9, an optical information reading device further comprising a decoding means in addition to the structure of the recording position detecting device described above. It can be realized as an invention. The decoding means decodes the information code in the image captured by the image capturing means and reads the information recorded as the information code.

According to the optical information reader having such a recording position detecting function, it is possible to judge whether or not the information code is recorded at an appropriate position of the article, and the information recorded as the information code is correct. Can be inspected. Also, for example, an admission ticket as an article,
In the case of boarding tickets and the like, when the information code is not printed at the position according to the standard of the ticket, it can be determined that the ticket is forged. From the viewpoint of preventing such forgery, as described in claim 10, the decoding process is performed only when the recording position determining means determines that the information code is recorded at an appropriate position of the article. It is also effective to configure the decoding means as described above.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a two-dimensional code reading device 1 of the embodiment, and FIG. 2 is a schematic perspective view of FIG. 1 viewed from a direction indicated by a symbol K in FIG.

The two-dimensional code reading device 1 is a stationary device, and is an article 7 conveyed by a belt conveyor 70.
The QR code printed on the upper surface (optical information recording surface) of No. 1 is read. This QR code will be described later. The two-dimensional code reading device 1 is fixed to a column (not shown) on the side of the belt conveyor 70 and is arranged above the belt conveyor 70.

The two-dimensional code reading device 1 includes an optical information reading unit 10 and an article detection unit 20, and the two units 10 and 20 are fixed to each other and integrated. Such an integrated structure contributes to improvement of maintainability. First, the article detection unit 20 will be described.

The article detection unit 20 is composed of a photo sensor, emits light downward, and detects the reflected light. Then, a signal indicating whether or not the reflected light is detected is output to the optical information reading unit 10. The light from the article detection unit 20 is transmitted to the belt conveyor 70 and the article 7.
Due to the difference in color of the upper surface of No. 1, when the belt conveyor 70 is irradiated, it is absorbed, while when the article 71 is irradiated, it is reflected. In this embodiment, when the article 71 reaches a predetermined position on the belt conveyor 70, specifically, the article 71 is
The tip surface 71a of the
It is simply called "position α". ), The reflected light shall be detected.

Next, the optical information reading unit 10 will be described. As shown in FIG. 3, the optical information reading unit 10 includes a control circuit 11, an illumination light emitting diode unit (hereinafter referred to as “illumination LED unit”) 12, a CCD area sensor 13, an amplifier circuit 14, and a binarization circuit 15. Specific ratio detection circuit 16, sync pulse generation circuit 17, address generation circuit 1
8, an image memory 19 and a communication I / F circuit 33.

The control circuit 11 includes a CPU, ROM, RA
It is configured as a computer system including M, I / O, etc., and executes a reading process described later according to a program stored in the ROM. Article detection unit 2 described above
The signal from 0 is input to the control circuit 11.

The illumination LED section 12 irradiates the QR code recorded on the upper surface of the article 71 with red light for illumination. In this embodiment, the illumination LED unit 12
Is configured as shown in FIG. Here, the configuration of the illumination LED unit 12 will be described. The illumination LED unit 12 is LE
D12a, light amount detection sensor 12b, transistor 12
c, an amplifier section 12d, and a resistor 12e.

As shown in FIG. 4, the signal from the control circuit 11 is input to the amplifier section 12d.
The output terminal of the amplifier section 12d is connected to the base terminal of the transistor 12c. Also, the transistor 12c
The collector terminal of is a battery (power source) via LED12a
It is connected to the. The emitter terminal of the transistor 12c is grounded via the resistor 12e. On the other hand, the light amount detection sensor 12b is connected to the control circuit 11, detects the light amount of the red light emitted from the LED 12a, converts it into an electric signal, and outputs it to the control circuit 11.

In this configuration, the control circuit 11 controls, based on the signal from the light amount detection sensor 12b, to increase the amount of current flowing through the LED 12a to the amplifier portion 12d when the amount of red light from the LED 12a decreases due to secular change or the like. Output a signal. Then, based on the control signal,
The amplifier section 12d varies the base current of the transistor 12c, and as a result, the amount of current flowing through the LED 12a increases. This makes it possible to keep the amount of red light emitted from the LED 12a constant.

The CCD area sensor 13 in FIG. 3 has a plurality of CCDs, which are two-dimensionally arranged light receiving elements, receives the reflected light from the upper surface of the article 71, and
A predetermined area on the upper surface of the image pickup device is imaged, and the two-dimensional image is output as a horizontal scanning line signal. The scanning line signal is amplified by the amplifier circuit 14 and output to the binarization circuit 15.

The amplifier circuit 14 has a gain corresponding to the gain control voltage input from the control circuit 11, and the CCD
The scanning line signal output from the area sensor 13 is amplified. The binarization circuit 15 binarizes the scanning line signal amplified by the amplification circuit 14 based on a threshold value, and outputs it to the specific ratio detection circuit 16 and the image memory 19.

The specific ratio detection circuit 16 detects a predetermined frequency component ratio, which will be described later, from the scanning line signals binarized by the binarization circuit 15, and outputs the detection result to the image memory 19. The binary data output from the binarization circuit 15 is stored in the image memory 19 as image data.
The CCD area sensor 13 detects an image at a timing designated by the control circuit 11. In this example,
In this way, the binary data is stored in the image memory 19 as image data after the predetermined frequency component ratio is detected by the specific ratio detection circuit 16, but as another method, the binary data is stored in the image memory 19. The image data may be stored, and then the characteristic pattern such as the frequency component ratio may be detected based on the image data.

The sync pulse generation circuit 17 outputs a sync pulse. The address generation circuit 18 counts this synchronizing pulse and generates an address for the image data storage area of the image memory 19. Binary data, which is image data, is written in units of 16 bits for each address. In this embodiment, writing is performed in 16-bit units, but it may be performed in 8-bit units.

The specific ratio detection circuit 16 for detecting the predetermined frequency component ratio is "1" in the signal from the binarization circuit 15.
Detecting the change from "0" to "0" or the change from "0" to "1", and counting the sync pulse output from the sync pulse generating circuit 17 between a certain change point and the next change point. Thus, the continuous length of light (white) and the continuous length of dark (black) in the two-dimensional image are obtained. This is because the QR code is targeted in this embodiment.

Here, the QR code will be described. Figure 8
The QR code is illustrated in the explanatory diagram of FIG. Q as shown in FIG.
The R code has three positioning symbols A, C, and D. When reading the QR code, first of all, this 3
One positioning symbol A, C, D is detected. The positioning symbols A, C, D have a specific ratio of lightness and darkness irrespective of the scanning direction, 1 (dark): 1 (bright): 3 (dark):
The pattern is 1 (bright): 1 (dark).

Therefore, it is possible to detect the positioning symbols A, C, D by judging that the ratio of the lengths obtained by the specific ratio detection circuit 16 has reached this specific ratio. Since the QR code has timing cells E and F in which bright and dark cells are alternately arranged between the positioning symbols A, C, and D, the QR code is further divided from the center position of this timing cell to another cell. The center position is determined and decoded.

The communication I / F circuit 33 communicates with an external device (not shown). The communication I / F circuit 33 transmits data to the external device through a communication light emitting device (not shown), and a communication light receiving device (not shown). To receive a signal from an external device. Next, the positional relationship between the two-dimensional code reading apparatus 1 and the conveyed article 71 will be described.

As shown in FIG. 2, on the lower surface of the optical information reading unit 10, that is, the surface on the belt conveyor 70 side, a reading port 10a for making reflected light from the upper surface of the article 71 incident is formed. . CCD area sensor 13
The field of view is, as shown in FIG. 5A, an area of 50 mm square on the upper surface of the article 71. As shown in FIG. 1, two QR codes are printed side by side in the carrying direction on the upper surface of the article 71 carried by the belt conveyor 70. An image is properly formed on the CCD area sensor 13 via the lens. This QR code is a 30 mm square code as shown in FIG. The state where the QR code is recorded at the proper position is as shown in FIG. That is, when viewed in the transport direction, the tip surface 71 of the article 71 is
The first QR code is recorded at an interval of 10 mm from a, and the first QR code and the second QR code are recorded at an interval of 20 mm. Further, when viewed in a direction perpendicular to the transport direction, each QR code is recorded at a distance of 30 mm from each of the end surfaces 71b and 71c of the article.

Therefore, if the QR code is in the proper position, the end of the field of view of the CCD area sensor 13 in the transport direction shown in FIG. 2 which is far from the position α, that is, the symbol β in FIG. When the front end surface 71a of the article 71 reaches the position (hereinafter, simply referred to as "position β") indicated by, the first QR code is entered in the center of the visual field of the CCD area sensor 13. In the present embodiment, this position β is 90 mm from the position α (see FIG. 2). Further, the second QR code comes to the center of the field of view of the CCD area sensor 13 when the article 71 further moves by 50 mm, and the tip surface 71a of the article 71 moves by 140 mm from the position α, That is, the position indicated by the symbol δ in FIG. 2 (hereinafter simply referred to as “position δ”
Say. It was when I came to.

In this embodiment, the QR captured as an image
The code is in the proper position on the article (the position shown in Fig. 5 (b))
In order to determine whether or not it is recorded in the above-mentioned position, the above-mentioned two positions β and δ and an intermediate position between these positions β and δ, that is, a position indicated by a symbol γ in FIG. ), A total of three images are captured at the timing when the article 71 is predicted to come to the three positions. The position γ is the position α
To 115 mm.

In this embodiment, it is assumed that there is no "shift" between the articles 71 in the direction perpendicular to the carrying direction. Next, the operation of the two-dimensional code reading device 1 of this embodiment will be described. The two-dimensional code reading device 1 of the present embodiment is characterized by the reading process executed by the control unit 11 of the optical information reading unit 10. In this reading process, the tip surface 71a of the article 71 is detected by detecting that the tip surface 71a of the article 71 has reached the position α based on a signal from the article detection unit 20, and determining whether a predetermined time has elapsed from the detection time. Is judged to have moved to the positions β, γ and δ mentioned above, and Q
Capture the R code as an image. At this time, in this reading process, QR images are extracted from the images captured at the positions β, γ, and δ.
The recording position of the code on the article 71 is calculated, it is determined whether the recording position is an appropriate position, and the decoding process is executed based on the determination result.

The details of this reading process will be described with reference to the flowchart of FIG. First step S100
At, it is determined whether or not the article 71 is detected. This process is based on a signal from the article detection unit 20 to determine that the front end surface 71a of the article 71 has reached the position α. If an article is detected here (S100: YE
S) and S110. On the other hand, while the article is not detected (S100: NO), this determination process is repeated.

In S110, it is determined whether or not a predetermined time has elapsed. The conveyor speed of the belt conveyor 70 is 6 according to the specifications.
It is assumed to be 00 mm / sec. Therefore, the time required for the front end surface 71a of the article 71 to move from the position α to the position β is 90/600 = 150 milliseconds. Similarly,
The time required to move from position α to position γ is 115
÷ 600≈192 milliseconds, and the time required to move to the position δ is 140 ÷ 600≈233 milliseconds. Therefore, three times are set as the predetermined time, that is, 150 milliseconds, 192 milliseconds, and 233 milliseconds.

When it is determined in S110 that the predetermined time has elapsed (S110: YES), the image is captured in S120, and the process proceeds to S130. In S130, it is determined whether or not a predetermined number of sheets have been captured. If only one or two images are captured here (S130: NO),
The process moves to S110 and the next image is captured. When the three images are captured (S130: YES), the process proceeds to S140.

In S140, the center coordinates of the positioning symbol of the QR code in the image are calculated. In this embodiment,
Of the three positioning symbols included in the QR code, the center coordinates of the upper left positioning symbol are calculated. For example, the following description will be continued on the assumption that each image is captured as shown in FIG. Note that FIG. 7A shows the first image area. Similarly, FIG. 7B shows the second sheet,
(C) shows the third image area.

In FIG. 7A, the first QR code 3
Since all the positioning symbols A, C, and D are in the image, the center coordinates of the positioning symbol A at the upper left and the symbol X1 are determined based on the arrangement of the positioning symbols A, C, and D.
The coordinates of the position (hereinafter, simply referred to as “position X1”) indicated by are calculated. Similarly for FIG. 7C, the center coordinates of the positioning symbol A on the upper left of the second QR code,
The coordinates of the position indicated by the symbol Y3 (hereinafter simply referred to as "position Y3") are calculated.

For FIG. 7B, the calculation is performed as follows. For the first QR code included in the image area of FIG. 7B, for example, only one positioning symbol C on the upper right is included in the image. In this case, it can be determined from the arrangement of the positioning symbols A, C, D that the positioning symbol included in the image is the upper right positioning symbol C. Therefore, the center coordinates of the upper left positioning symbol A (position coordinates outside the image) are obtained from the center coordinates of the positioning symbol. This position is shown as a symbol X2 in the drawing (hereinafter, simply referred to as "position X2").

On the other hand, 2 included in the image area of FIG.
For the second QR code, the two upper left and lower left positioning symbols A and D are included in the image. In this case, from the arrangement of the positioning symbols A, C, and D, it can be determined that the upper positioning symbol of the vertically aligned positioning symbols is the upper left positioning symbol A.
Therefore, the center coordinates of the positioning symbol are obtained. This position is shown as a symbol Y2 in the drawing (hereinafter, simply referred to as "position Y2").

In this way, the center coordinates as position information are calculated for each image. However, if there are no three positioning symbols in the image, the center coordinates of the positioning symbols cannot be calculated. S1 that continues there
In 50, it is determined whether or not the center coordinates of the positioning symbol of the QR code can be calculated in S140. When the center coordinates can be calculated (S150: YES), S160
Move to. On the other hand, when the center coordinates cannot be calculated (S150: NO), that is, when there are no three positioning symbols in the image, it is determined that the information code recording position is not appropriate, and the process proceeds to S180.

In S160, the transport speed of the article 71 is calculated from the center coordinates calculated for each image. Here, the position X calculated from each image of FIGS.
The transport speed of the article 71 is calculated based on the coordinate value of 1 and the position X2 and the image capture timing. Specifically, 1
Since it is considered that the position has moved by the difference between the position X1 and the position X2 within 92-150 = 42 msec, the distance indicated by the difference between the position X1 and the position X2 may be divided by the time of 42 msec. Since the transport speed can be known based on the position information of the same QR code, based on the coordinate values of the positions Y2 and Y3 calculated from the images in FIGS. 7B and 7C and the image capture timing. The transportation speed of the article 71 may be calculated.

The transport speed of the belt conveyor 70 is 600 mm / sec in the specification, but an accurate transport speed is calculated by the processing of S160. This is because the transport speed varies by about 5% even among the same products, and may change over time.

In the following 170, the recording position for the QR code article is calculated. When the transport speed is calculated in S160, which region of the article 71 is imaged can be known from this transport speed. For example, the first image is the item 7
It is taken 150 milliseconds after the 1 comes to position α. Therefore, when the article 71 moves by a distance obtained by multiplying the carrying speed by 150 milliseconds, the first image is captured.

Here, the recording position of the first QR code is calculated from the coordinate value of the position X1 of the first image area shown in FIG. 7A. Further, since the coordinates of the position X2 and the position Y2 are calculated from the image shown in FIG. 7B, the recording position of the second QR code is the first based on these two position X2 and Y2 coordinate values. It is calculated as a relative position with respect to the recording position of the QR code.

Then, in the next S180, it is determined whether or not the recording position of the QR code is proper. If the recording position of the QR code is appropriate (S180: YES), that is, if the positional relationship shown in FIG.
Move to. On the other hand, when the recording position of the QR code is not appropriate (S180: NO), the process proceeds to S200.

In S190, the decoding process is performed, and then the reading process is terminated. For example, the first QR code is decoded based on the first image shown in FIG. 7A, and the second QR code is converted to the second image shown in FIG. 7C. Decoding processing is performed based on this.

At S200, a warning process is executed, and then this reading process is terminated. It is conceivable that the warning process is a process of notifying the user of the abnormality by using, for example, a buzzer of the optical information reading unit 10 (not shown). Further, if the optical information reading unit 10 is provided with a display device, it may be displayed on the display device.

Next, the two-dimensional code reading apparatus 1 of this embodiment
Explain the effect of. This two-dimensional code reader 1
Then, the article detection unit 20 detects that the article 71 has arrived at a predetermined position (S100 in FIG. 6), and captures an image when a predetermined time has elapsed from that point (S110,
S120), the center coordinates of the positioning symbol included in the QR code in the image are calculated (S140). The recording position of the QR code on the article 71 is calculated from the center coordinates (S170), and if the recording position is proper (S180: Y
ES) and decoding processing is performed (S190). On the other hand, if the center coordinates of the positioning symbol cannot be calculated (S15)
0: NO), or if the recording position of the QR code is not appropriate (S180: NO), a warning process is executed (S2).
00).

That is, according to the two-dimensional code reading apparatus 1, it is possible to easily determine whether or not the QR code recorded on the article 71 moving on the conveying path is recorded at an appropriate position. For example, conventionally, there is no device that determines whether or not an information code such as a QR code is recorded at an appropriate position of such a moving article. Therefore, for example, if the QR code is printed on an article and then it is tried to inspect whether or not the QR code is printed at an appropriate position, it is inspected one by one. On the other hand, if the two-dimensional code reading device 1 is used, it is possible to inspect whether or not the QR code is printed at an appropriate position of the article while the article is moving on the conveyance path. Further, if the information is printed at the proper position, the decoding process is performed thereafter, so it is possible to determine whether the information recorded as the QR code is correct based on the decoding process result.

If the present two-dimensional code reading apparatus 1 is used to read a QR code printed on, for example, an entrance ticket or a ticket, a ticket in which the QR code is not printed at a position conforming to the standard is used. , QR code cannot be read. Therefore, it is effective in preventing the use of forged tickets.

Furthermore, in the present two-dimensional code reading device 1, a plurality of images are captured at a predetermined capture timing,
The transport speed of the article 71 is calculated based on these images (S160). Then, the recording position of the QR code is calculated based on this transport speed (S170). This makes it possible to accurately calculate the recording position of the QR code even if the conveying speed of the conveying device varies or changes over time, and as a result, the QR code is recorded at an appropriate position. Whether or not it can be determined with high accuracy. From this point as well, it is effective in preventing the use of the forged ticket as described above.

Further, in the present two-dimensional code reading device 1, Q
For the R code, the center coordinates of the positioning symbol included in the QR code are calculated as the position information for specifying the code area in the image (S140). Therefore, the position information calculation process is simple.

The control circuit 11 of the article detecting unit 20 and the optical information reading unit 10 of this embodiment corresponds to "detecting means", and the illumination LED of the optical information reading unit 10 is used.
The section 12 corresponds to “light emitting means”, the CCD area sensor 13 of the optical information reading unit 10 corresponds to “image capturing means”, and the control circuit 11 of the optical information reading unit 10 includes “positional information calculating means” and “positional information calculating means”. It corresponds to "code recording position calculating means", "code recording position determining means", and "decoding means".

Further, the processing of S100 in FIG. 6 corresponds to the processing as the detecting means, the processing of S110 to S130 corresponds to the processing as the image capturing means, and the processing of S140 as the position information calculating means. And the processing of S170 corresponds to the processing as the code recording position calculating means, and S1
The processing of 80 corresponds to the processing as the code recording position determination means, and the processing of S190 corresponds to the processing as the decoding means.

As described above, the present invention is not limited to the embodiments as described above, and may be implemented in various forms without departing from the gist of the present invention. (1) In the above embodiment, it was assumed that the articles 71 conveyed on the conveyance path were aligned in a predetermined direction.
It is also conceivable that a certain article 71 is conveyed in a state of being rotated by 180 degrees about an axis perpendicular to the code recording surface as the rotation axis, so that the front and back of the article 71 are mixed with respect to the conveyance path.

In this case, the QR code in the captured image may be captured in the image in a state of being rotated by 180 degrees. Therefore, for example, immediately after the affirmative determination is made in S130, it is conceivable to add a step of determining the orientation of the QR code by the arrangement of the positioning symbols A, C, D included in the QR code. This determination processing is executed based on an image in which all three positioning symbols A, C, D of the QR code as shown in FIG. 7A or 7C are present. That is, 3
When the two positioning symbols A, C, and D are on the upper left, lower left, and upper right, it can be determined that there is no rotation. In addition, if it is located at the lower right, upper right, or upper left, it can be determined that it is rotated 180 degrees. Further, for example, if the article 71 has a square shape or a cubic shape, it may be conveyed in a state of being rotated by 90 degrees about an axis perpendicular to the code recording surface as a rotation axis.

In that case, it may happen that the QR code in the captured image is captured in the image in a state of being rotated by 90 degrees. At this time, CC is larger than that in the above embodiment.
If the image in which all the three positioning symbols of one QR code are present can be obtained by, for example, configuring the field of view of the D area sensor to be wide, the positioning symbols are displayed in the upper right, upper left, and lower right. If there is right direction (clockwise)
It can be determined that it is rotated by 90 degrees. Further, when it is located at the lower left, the lower right, and the upper left, it can be determined that the state has been rotated 90 degrees to the left (counterclockwise).

Then, in the subsequent steps, the recording position of the QR code is calculated in consideration of this judgment result, and it is judged whether or not the recording position is proper. For example, when the QR code is rotated by 90 degrees or 180 degrees and captured in the image, the calculated center coordinates may be corrected to calculate the center coordinates in the non-rotated state. According to this structure, the article 7 transported on the transport path
Even when the orientation of 1 is not constant, it can be determined whether or not the information code is recorded at an appropriate position on the article.

(2) Further, although the QR code is used in the above embodiment, the present invention is similarly applied to a two-dimensional code or a bar code other than the QR code by changing the calculation algorithm of the position information. be able to. (3) In the above embodiment, the article detection unit 20 is configured by using a photo sensor, and detects that the article 71 has arrived at the position α (see FIG. 2) based on the reflected light from the article 71. It was

Instead of the article detection unit 20, a special ink detection unit may be integrated with the optical information reading unit 10. In that case, the special ink is applied to the article 71. For example, as shown in FIG. The special ink is so-called magnetic ink or ink that modulates and reflects light of a predetermined wavelength. Such special inks normally absorb visible light and are therefore invisible to the human eye. Therefore, as shown in FIG. 9, it is conceivable to apply the QR code over the QR code. Then, the special ink sensing unit irradiates the special ink applied to the article 71 with light having a predetermined wavelength, and detects the modulated and reflected light. This may detect that the article 71 has reached the position α.

(4) Assuming that the special ink is applied to the article 71, the QR code is a relative position from the position where the special ink is applied (for example, the application position shown by the arrow in FIG. 9). The recording position may be calculated. (5) Further, as shown in FIG. 10, the article detection unit 2
0, the special ink sensing unit 21, and the optical information reading unit 10 may be adopted. At this time,
The units 10, 20, and 21 are integrated so that their positional relationship does not change. If such an integrated configuration is adopted, each unit 1 can be installed when the device is installed.
It is advantageous in that the dimensional error can be reduced as compared with the case where 0, 20, and 21 are separately installed. And
The article detection unit 20 detects that the article 71 has reached the position α, and the special ink detection unit 21 moves the article 71 to a position different from the position α (the position indicated by the symbol ε in FIG. 10). Try to detect when you come.

In this way, the article detection unit 20
It is also possible to calculate the transport speed of the article 71 based on the time when the article 71 is detected by and the time when the special ink sensing unit 21 detects the article 71. Also, the recording position of the QR code can be calculated based on the time when the special ink sensing unit 21 detects the article 71. Therefore, the units 20, 2 of both the article detection unit 20 and the special ink detection unit 21 are
If the recording position of the QR code is calculated based on each detection time point of the article 71 by 1, the recording position of the QR code can be calculated more accurately.

[Brief description of drawings]

FIG. 1 is a perspective view of a two-dimensional code reader according to an embodiment.

FIG. 2 is a schematic perspective view of the perspective view shown in FIG. 1 viewed from a direction indicated by a symbol K in FIG.

FIG. 3 is a block diagram showing a schematic configuration of a two-dimensional code reading device according to an embodiment.

FIG. 4 is a circuit diagram illustrating a configuration of an illumination light emitting diode including an optical information reading unit.

FIG. 5 is an explanatory diagram showing the positions of QR codes recorded on the upper surface of the article.

FIG. 6 is a flowchart showing a reading process executed by the two-dimensional code reading device.

FIG. 7 is an explanatory diagram showing position information of a QR code in an image and calculation of a difference from a reference position.

FIG. 8 is an explanatory diagram illustrating a QR code.

FIG. 9 is an explanatory diagram showing application of special ink to an article.

FIG. 10 is an explanatory diagram showing a configuration of a two-dimensional code reading device according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Two-dimensional code reading device 10 ... Optical information reading unit 10a ... Reading port 11 ... Control circuit 12 ... Illumination light emitting diode part 13 ... CCD
Area sensor 14 ... Amplification circuit 15 ... Binarization circuit 16 ... Specific ratio detection circuit 17 ... Sync pulse generation circuit 18 ... Address generation circuit 19 ... Image memory 20 ... Article detection unit 21 ... Special ink detection unit 33 ... Communication I / F Circuit 70 ... Belt conveyor 71 ... Article 71a ... Tip surfaces 71b, 71c ... End surface

Continuation of the front page (56) Reference JP-A-9-185671 (JP, A) JP-A-11-31225 (JP, A) JP-A-8-101016 (JP, A) JP-A-7-243808 (JP , A) Special Table H11-502348 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 11/00 G06T ^7/ 00-7/60

Claims (10)

(57) [Claims] 1. A detection means for detecting that an article moving on a conveyance path has arrived at a predetermined position on the conveyance path, a light emitting means for emitting light to a code recording surface of the article, and the detection means for the article. An image that captures the information code recorded on the code recording surface of the article as an image based on the reflected light of the light emitted by the light emitting means after a predetermined time has elapsed from the time when it was detected that A capturing means; a position information calculating means for calculating position information capable of specifying a region where the information code exists in the image based on the image captured by the image capturing means; Based on the calculated position information,
An information code recording position detecting device, comprising: a code recording position calculating means for calculating a recording position of the information code on the article in at least the carrying direction. 2. The recording position detecting device according to claim 1, further, based on the recording position calculated by the code recording position calculating means, whether the information code is recorded at an appropriate position of the article. An information code recording position detecting device comprising a code recording position judging means for judging whether or not the information code is recorded. 3. The recording position detecting device according to claim 1, wherein the position information calculating means calculates the position information based on a positioning symbol included in the information code. Recording position detection device. 4. The recording position detecting device according to claim 3, wherein the position information calculating unit determines the center coordinates of the positioning symbol of the QR code as the position information, on the assumption that the information code is a QR code. An information code recording position detecting device characterized by: 5. The recording position detecting device according to claim 3, further comprising orientation determining means for determining the orientation of the information code in the image based on a positioning symbol included in the information code. The information code recording position detecting device is characterized in that the code recording position calculating means calculates the recording position in accordance with a result of the judgment by the orientation judging means. 6. The recording position detection device according to claim 1, wherein the image capturing unit is configured to detect the detection unit, assuming that a plurality of different times are set as the predetermined time. The image is captured at a plurality of time points after the predetermined time has elapsed since it was detected that the article came to a predetermined position, An information code recording position detecting device, characterized in that the code recording position calculating means calculates the recording position based on position information calculated for each of the plurality of images. 7. The recording position detecting device according to claim 6, wherein the code recording position calculating means determines a relative position with respect to a specific information code on the assumption that a plurality of information codes are recorded on the article. An information code recording position detecting device, which is calculated as the recording position. 8. The recording position detecting apparatus according to claim 6 or 7, wherein the predetermined time is set so that the position information for the same information code is calculated from each of the plurality of images. As a premise, the code recording position calculating means calculates the recording position in consideration of a conveyance speed of the article that can be calculated based on position information for the same information code. Detection device. 9. The recording position detecting device according to claim 1, wherein the information code in the image captured by the image capturing means is decoded and recorded as the information code. An optical information reading device comprising: a decoding unit for reading information. 10. The recording position detecting device according to claim 2, wherein the information code in the image captured by the image capturing means is decoded and recorded as the information code. Decoding means for reading information is provided, and the decoding means performs the decoding process only when the code recording position determination means determines that the information code is recorded at an appropriate position of the article. An optical information reading device characterized by the above.