JP2000337853A - Detecting device for record position of information code, and optical information reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detecting device for record position of information code, together with an optical information reading device comprising a record position detecting function, which inspects whether the information code recorded in a moving article is recorded at an appropriate position of the article. SOLUTION: An article detecting unit detects that an article has come to a specified position (S100), an image is taken in when a specified time has elapsed after that time point (S110 and S120), and the center coordinate of a alignment symbol which a QR code in an image comprises is calculated (S140). The record position of the GR code to the article is calculated from the center coordinate (S170), and decoding is processed (S190) if the record position is appropriate (S180: YES). If the center coordinate of the alignment symbol can not be calculated (S150: N0), or the record position of the GR code is not appropriate (S180: N0), an alert process is performed (S200).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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 of 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 optical information to an optical information recording surface, and a light receiving element is used. CCD with photo sensors, etc.
There is known a method of using a sensor to read an information code as an image from the reflected light into an apparatus and decode the image.

Some optical information reading apparatuses of this type read information codes that are moving, for example, information codes recorded on articles 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, the CCD sensor is exposed, and the information code is captured 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 shifted, for example, the information code may protrude from the field of view of the CCD sensor, and a situation may occur in which a part or all of the information code area does not enter the captured image.

Therefore, it is desirable to be able to check whether or not the recorded information code is at an appropriate position after recording the information code on the article. However, conventionally, there is no device for checking whether the information code recorded on the article as described above is attached to an appropriate position of the article.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and is for checking whether an 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]

According to a first aspect of the present invention, there is provided an information code recording position detecting apparatus, comprising: an article moving along a transport path; The detecting means detects that the position has been reached. For example, it is detected that an article conveyed by the belt conveyor has moved to a predetermined position on the belt conveyor. It is conceivable that this detection means is configured using, for example, a photo sensor. For example, a configuration in which light incident on the photosensor is blocked during the movement of the article or a configuration in which light is incident on the photosensor by reflection from the article is employed, and detection is performed based on a signal change of the photosensor. Further, it is conceivable that the detecting means is configured by using a sensor for detecting the special ink applied to the article. The special ink is a so-called magnetic ink or an ink that modulates and reflects light having a predetermined wavelength.
Such a special ink is applied to an article, and the detecting means irradiates the special ink with light of a predetermined wavelength to detect the modulated reflected light.

When the detecting means detects that the article has arrived at a predetermined position on the transport path, the image capturing means captures an image after a lapse of a predetermined time from the detection time. The predetermined time is a time required for the article to move from the predetermined position to a position where the information code recorded at an appropriate 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 unit is configured using, for example, a CCD sensor, receives reflected light of light emitted toward the code recording surface of the article by the light emitting unit, and captures an information code as an image.

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

The code recording position calculating means calculates the recording position of the information code in at least the transport direction for the article based on the position information. Here, the recording position "at least in the transport direction" is calculated when each article is transported so that "shift" in the direction perpendicular to the transport direction does not occur, or the article in the direction perpendicular to the transport direction is calculated. If at least one of the ends 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 point that an image pickup area of an article is determined if an image is acquired at a predetermined acquisition timing on the assumption that the article conveying speed is constant. Therefore, an image is captured after a lapse of a predetermined time from the point at which the article is detected, and position information capable of specifying a code area in the image is calculated, thereby calculating the recording position of the information code on the article as a 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 position. The recording position can be inspected. Incidentally, it is conceivable to calculate an absolute position, which is a distance from the end of the article, as the recording position for the article. Further, as described above, if the configuration is such that the special ink is applied to the article and the detecting means detects the article with the special ink, a relative position of a distance from the position where the special ink is applied is calculated. You may. Furthermore, if a predetermined information code position (proper position) is stored, it may be possible to calculate a relative position that is a distance from the proper position.

If the proper position of the information code is stored as described above, the code recording position determining means may further determine the information based on the recording position calculated by the code recording position calculating means. It may be determined 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 of the article.

When calculating position information such as the positions of four vertices of a quadrilateral code area as described above,
For example, the calculation may be performed based on a 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 the code area can be specified in an image. Therefore, the position information described above can be easily calculated by using this positioning symbol.

As an example of the position information, it is conceivable to adopt the positions of the four vertexes of the quadrilateral code area as described above, but the present invention is not limited to this. For example, if the positioning symbol is detected, the size of the code area can be known, so that the position of at least one of the four vertices may be used as the position information. In the case of a QR code, for example, it is conceivable that the center information of the QR code positioning symbol is used as the position information.

The QR code has three positioning symbols called finder patterns. And
The center coordinates of the positioning symbol can be easily obtained as compared with calculating four vertex positions for specifying the code area. Therefore, it is advantageous in that the calculation processing of the position information is further simplified.

Incidentally, there may be a case where the direction of an article conveyed along the conveyance path is not constant. For example, when a rectangular or rectangular parallelepiped article is transported in the longitudinal direction, there is no distinction between the front and rear of the article shape, so that the article may be rotated 180 degrees with the axis perpendicular to the code recording surface as the rotation axis. Conceivable. Therefore, when the code recording surface is imaged, the direction of the information code may not be constant. That is, the information code is, for example, 90 degrees, 180 degrees.
It is conceivable that the image is captured in the image in a rotated state such as degrees.

Therefore, as set forth in claim 5,
It is good to have composition provided with direction judging means. The direction determining means determines the direction of the information code in the image based on the positioning symbol of the information code. For example, Q
Taking the R code as an example, the above-described three positioning symbols are provided at the upper left, lower left, and upper right of the code area. Therefore, the direction of the code can be determined from the arrangement of the positioning symbols. At this time, the code recording position calculating means calculates the recording position of the information code according to the result of the determination by the direction determining means. Thereby, even when the direction of the article conveyed on the conveyance path is not constant, the recording position of the information code can be appropriately calculated.

The image capturing means may capture a plurality of images. For example, it is conceivable to adopt the configuration described in claim 6. That is, in this configuration, a plurality of different times are set as the predetermined time, and a plurality of images are captured at a plurality of times for one article by the image capturing unit. Then, the position information calculating means calculates position information for each of the plurality of images, and the code recording position calculating means calculates 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 cope with a case where there are a plurality of information codes recorded on an 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 in which a plurality of images are captured,
Assuming that a plurality of information codes are recorded on the article, the code recording position calculating means may calculate the relative position with respect to the specific information code as the recording position. Good.

In the above description, it is assumed that the moving speed (conveying speed) of the articles is constant. However, for example, even if the conveying devices have the same specifications, the conveying speed may vary. . In addition, the transport speed may change due to aging. Therefore, it is conceivable to employ the configuration described in claim 8. This configuration is based on the premise that a predetermined time is set so that position information for the same information code is calculated from each of a plurality of images.
The code recording position calculating means calculates the recording position in consideration of the transport speed of the article which 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 obtained at relatively short intervals in consideration of the assumed article conveyance speed 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 transport speed of the article can be known. Therefore, an accurate recording position of the information code can be calculated based on the transport speed. As a result, there is an excellent effect that the recording position of the information code can be accurately calculated even if the transport speed varies or changes over time.

Although the invention has been described as an invention of a recording position detecting device for information codes, an optical information reading device provided with a decoding means in addition to the above-mentioned recording position detecting device is provided. 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 reading apparatus having such a recording position detecting function, it can be determined 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 checked. Also, for example, admission tickets as goods,
Considering a ticket or the like, if the information code is not printed at a position according to the standard of the ticket, it can be determined that the ticket is forged. From the viewpoint of preventing such forgery, the decoding process is performed only when it is determined by the recording position determining unit that the information code is recorded at an appropriate position on the article. It is also effective to configure the decoding means.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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 reader 1 according to an 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 reader 1 is a stationary type device, and the articles 7 conveyed by the belt conveyor 70 are
The QR code printed on the upper surface (optical information recording surface) of the device 1 is read. This QR code will be described later. The two-dimensional code reader 1 is fixed to a support (not shown) on the side of the belt conveyor 70, and is disposed above the belt conveyor 70.

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

The article detection unit 20 is constituted by using 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 the color of the upper surface of the device 1, when the light is irradiated on the belt conveyor 70, the light is absorbed, and when the light is irradiated on the article 71, the light is reflected. In this embodiment, when the article 71 reaches a predetermined position on the belt conveyor 70, specifically, the article 71
Is located at the position indicated by the symbol α in FIG.
It is simply called “position α”. ), The reflected light is 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, a light emitting diode unit for illumination (hereinafter, referred to as “illumination LED unit”) 12, a CCD area sensor 13, an amplification circuit 14, a binarization circuit 15, Specific ratio detection circuit 16, synchronization 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 having 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 the present embodiment, the illumination LED unit 12
Are configured as shown in FIG. Here, the configuration of the illumination LED unit 12 will be described. The lighting 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, a signal from the control circuit 11 is input to an amplifier 12d.
The output terminal of the amplifier section 12d is connected to the base terminal of the transistor 12c. Also, the transistor 12c
Is connected to a battery (power supply) via the LED 12a.
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 amount of red light emitted from the LED 12a, converts the light amount into an electric signal, and outputs the electric signal to the control circuit 11.

In this configuration, the control circuit 11 controls the amplifier 12d to increase the amount of current flowing through the LED 12a when the amount of red light from the LED 12a decreases due to aging or the like based on a signal from the light amount detection sensor 12b. 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. Thus, the amount of red light emitted from the LED 12a can be made constant.

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

The amplification circuit 14 has a gain corresponding to the gain control voltage input from the control circuit 11 and has a CCD
The scanning line signal output from the area sensor 13 is amplified. The binarizing circuit 15 binarizes the scanning line signal amplified by the amplifying circuit 14 based on a threshold and outputs the binarized signal to the specific ratio detecting 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 signal 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 specified by the control circuit 11. In this embodiment,
As described above, after the specific frequency component ratio is detected by the specific ratio detection circuit 16, the binary data is stored in the image memory 19 as image data. However, as another method, the binary data is stored in the image memory 19. It may be configured to store as image data and thereafter detect a characteristic pattern such as a frequency component ratio based on the image data.

The synchronization pulse generation circuit 17 outputs a synchronization pulse. The address generation circuit 18 counts this synchronization 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 16-bit units for each address. In this embodiment, writing is performed in units of 16 bits, but writing may be performed in units of 8 bits, for example.

The specific ratio detecting circuit 16 for detecting a predetermined frequency component ratio is "1" in the signal from the binarizing circuit 15.
Detecting a change from “0” to “0” or a change from “0” to “1”, and counting the number of synchronization pulses output from the synchronization pulse generation 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 in the present embodiment, the QR code is targeted.

Here, the QR code will be described. FIG.
The QR code is illustrated in the explanatory diagram of FIG. As shown in FIG.
The R code has three positioning symbols A, C, and D. When reading a QR code,
Two positioning symbols A, C, and D are detected. The positioning symbols A, C, and D have a specific ratio of light and dark regardless of the scanning direction, 1 (dark): 1 (bright): 3 (dark):
1 (bright): 1 (dark).

Accordingly, the positioning symbols A, C, and D can be detected by determining that the length ratio obtained by the specific ratio detection circuit 16 has reached the specific ratio. Since the QR code has timing cells E and F in which light and dark cells are alternately arranged between the positioning symbols A, C and D, the QR code further moves from the center position of the timing cell to other cells. 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 via a communication light emitting element (not shown), or transmits light to a communication light receiving element (not shown). Via the external device. Next, the positional relationship between the two-dimensional code reader 1 and the article 71 to be conveyed will be described.

As shown in FIG. 2, on the lower surface of the optical information reading unit 10, that is, on the surface on the side of the belt conveyor 70, there is formed a reading opening 10a through which reflected light from the upper surface of the article 71 is incident. . CCD area sensor 13
Is a 50 mm square area on the upper surface of the article 71 as shown in FIG. As shown in FIG. 1, two QR codes are printed on the upper surface of the article 71 conveyed by the belt conveyor 70 side by side in the conveying direction. An image is appropriately 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 this QR code is recorded at an appropriate position is as shown in FIG. That is, when viewed in the transport direction, the leading end surface 71 of the article 71
The first QR code is recorded at an interval of 10 mm from a, and the second QR code is recorded at an interval of 20 mm from the first QR code. When viewed in a direction perpendicular to the transport direction, each QR code is recorded at an interval of 30 mm from the end surfaces 71b and 71c of the article.

Therefore, if the QR code is at an appropriate position, the end of the field of view of the CCD area sensor 13 in the transport direction shown in FIG. 2 that is farther from the position α, ie, the symbol β in FIG. When the tip surface 71a of the article 71 reaches the position indicated by (hereinafter, simply referred to as “position β”), the first QR code enters the center of the field of view of the CCD area sensor 13. In this embodiment, the position β is 90 mm from the position α (see FIG. 2). The second QR code comes just in the center of the field of view of the CCD area sensor 13 when the article 71 has further moved 50 mm, and the position where the tip surface 71a of the article 71 has moved 140 mm from the position α. That is, the position indicated by the symbol δ in FIG.
That. It is when I came to).

In this embodiment, the QR captured as an image
The code is at the proper position of the article (the position shown in FIG. 5 (b))
In order to judge whether or not the position is recorded in the above-mentioned position, the two positions β and δ described above and an intermediate position between the positions β and δ, that is, a position indicated by a symbol γ in FIG. 2 (hereinafter, simply referred to as “position γ”). 3), 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
And 115 mm.

In this embodiment, it is assumed that there is no "shift" between the articles 71 in the direction perpendicular to the transport direction. Next, the operation of the two-dimensional code reader 1 of the present embodiment will be described. The two-dimensional code reading device 1 of the present embodiment is characterized by a reading process executed by the control unit 11 of the optical information reading unit 10. In this reading process, the arrival of the tip surface 71a of the article 71 at the position α is detected based on a signal from the article detection unit 20, and the elapse of a predetermined time from the detection point is determined. Is determined to have moved to the positions β, γ, δ described above, and Q
The R code is captured as an image. At this time, in this reading process, QR images are obtained from the images captured at the positions β, γ, and δ.
The recording position of the code with respect to the article 71 is calculated, it is determined whether or not the recording position is an appropriate position, and a decoding process is executed based on the determination result.

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

In S110, it is determined whether a predetermined time has elapsed. The conveyor speed of the belt conveyor 70 is 6
It is assumed that the speed is 00 mm / sec. Therefore, the time required for the tip 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 ms, and the time required to move to position δ is 140/600/233 ms. Therefore, three predetermined times, that is, 150 milliseconds, 192 milliseconds, and 233 milliseconds are set.

If it is determined in S110 that the predetermined time has elapsed (S110: YES), an image is fetched in S120, and the flow shifts to S130. In S130, it is determined whether or not a predetermined number has been captured. Here, when only one or two images have been captured (S130: NO),
The process proceeds to S110 to capture the next image. If three images have been captured (S130: YES), the process proceeds to S140.

In S140, the center coordinates of the QR code positioning symbol in the image are calculated. In this embodiment,
The center coordinates of the upper left positioning symbol among the three positioning symbols of the QR code are calculated. For example, the following description is continued assuming that each image is captured as shown in FIG. FIG. 7A shows the first image area. Similarly, FIG. 7B shows the second sheet, and FIG.
(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 upper left positioning symbol A and the symbol X1 are determined based on the arrangement of the positioning symbols A, C, and D.
The coordinates of the position indicated by (hereinafter, simply referred to as “position X1”) are calculated. 7C, similarly, the center coordinates of the positioning symbol A at 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.

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

On the other hand, 2 included in the image area of FIG.
As for the first QR code, two upper-left and lower-left positioning symbols A and D are included in the image. In this case, it can be determined from the arrangement of the positioning symbols A, C, and D that the positioning symbol above the positioning symbols arranged vertically 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 figure (hereinafter, simply referred to as “position Y2”).

In this way, the center coordinates as position information are calculated for each image. However, if no three positioning symbols are present 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 QR code positioning symbol have been calculated in S140. If the center coordinates can be calculated (S150: YES), S160
Move to. On the other hand, if the center coordinates cannot be calculated (S150: NO), that is, if no three positioning symbols are present in the image, it is determined that the recording position of the information code 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 of the images in FIGS.
The transport speed of the article 71 is calculated based on the coordinate values of the position 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 during 92-150 = 42 milliseconds, the distance indicated by the difference between the position X1 and the position X2 may be divided by the time of 42 milliseconds. Since the transport speed can be determined based on the position information of the same QR code, based on the coordinate values of the position Y2 and the position Y3 calculated from each image of FIGS. 7B and 7C and the image capture timing. Alternatively, the transport speed of the article 71 may be calculated.

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

At step 170, the recording position of the QR code for the article is calculated. When the transport speed is calculated in S160, it is possible to know which region of the article 71 is being imaged from the transport speed. For example, the first image is an article 7
It is taken in 150 milliseconds after the point 1 comes to the position α. Therefore, when the article 71 moves by a distance obtained by multiplying the transport 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 determined based on the coordinate values of the two positions X2 and Y2. Is calculated as a relative position 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 appropriate. 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, if the recording position of the QR code is not appropriate (S180: NO), the process proceeds to S200.

In S190, a decoding process is performed, and thereafter, the main reading process ends. 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. That is, the decoding process is performed based on this.

In S200, a warning process is executed, and thereafter, the main reading process ends. It is conceivable that the warning process is to notify the user of an abnormality using, for example, a buzzer or the like of the optical information reading unit 10 (not shown). If the optical information reading unit 10 is provided with a display device, this may be displayed on the display device.

Next, the two-dimensional code reader 1 of this embodiment
The effect exhibited by will be described. The present two-dimensional code reader 1
Then, the article detection unit 20 detects that the article 71 has reached the predetermined position (S100 in FIG. 6), and captures an image when a predetermined time has elapsed from that point (S110, 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 appropriate (S180: Y
ES), a decoding process is performed (S190). On the other hand, when the center coordinates of the positioning symbol cannot be calculated (S15
0: NO) or when 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 reader 1, it is possible to easily determine whether or not the QR code recorded on the article 71 moving on the transport path is recorded at an appropriate position. For example, conventionally, there is no device that determines whether an information code such as a QR code is recorded at an appropriate position of such a moving article. Therefore, for example, after printing a QR code on an article, if it is attempted to check whether or not the QR code is printed at an appropriate position, the inspection is performed one by one. On the other hand, if the two-dimensional code reader 1 is used, it is possible to inspect whether the QR code is printed at an appropriate position on the article while the article is moving on the transport path. Further, if the information is printed at an appropriate position, the decoding process is performed thereafter, so that it is possible to determine whether or not the information recorded as the QR code is correct based on the result of the decoding process.

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

Further, in the present two-dimensional code reader 1, a plurality of images are fetched at a predetermined fetch timing.
The conveyance speed of the article 71 is calculated based on these images (S160). Then, the recording position of the QR code is calculated based on the transport speed (S170). Accordingly, even if the transport speed of the transport device varies or changes over time, the accurate recording position of the QR code can be calculated, and as a result, the QR code is recorded at an appropriate position. It can be determined with high accuracy whether or not there is. From this point as well, it is effective in preventing the use of forged tickets as described above.

In the present two-dimensional code reader 1, Q
The center coordinates of the positioning symbol included in the QR code are calculated as position information for specifying the code area in the image for the R code (S140). Therefore, the calculation processing of the position information is simple.

The article detection unit 20 and the control circuit 11 of the optical information reading unit 10 of this embodiment correspond to “detection means”, and the illumination LED of the optical information reading unit 10
The unit 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 “position information calculating means”, Code recording position calculation means "," code recording position determination means "and" decoding means ".

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

As described above, the present invention is not limited to such an embodiment, and can be implemented in various modes without departing from the gist of the present invention. (1) In the above embodiment, it is assumed that the articles 71 conveyed on the conveying path are 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 a rotation axis.

In this case, the QR code in the captured image may be captured in the image in a state where the QR code is rotated by 180 degrees. Therefore, for example, immediately after a positive determination in S130, a step of determining the direction of the QR code based on the arrangement of the positioning symbols A, C, and D included in the QR code may be added. This determination processing is performed based on an image in which all three positioning symbols A, C, and 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 at the upper left, lower left, and upper right, it can be determined that there is no rotation. In addition, when it is at the lower right, upper right, and upper left, it can be determined that it is rotated by 180 degrees. Further, for example, if the article 71 is square or cubic, the article 71 may be conveyed while being rotated 90 degrees around an axis perpendicular to the code recording surface as a rotation axis.

In this case, it is possible that the QR code in the captured image is captured in the image with the orientation rotated by 90 degrees. In this case, CC is higher than in the above embodiment.
If it is possible to obtain an image in which all three positioning symbols of one QR code are present, for example, by configuring the field of view of the D area sensor wide, the positioning symbols can be positioned at the upper right, upper left, and lower right. If there is, right (clockwise)
Can be determined to be in a state rotated by 90 degrees. In addition, when it is at the lower left, lower right, and upper left, it can be determined that it is in a state rotated 90 degrees to the left (counterclockwise).

In the subsequent steps, the recording position of the QR code is calculated in consideration of the result of the determination, and it is determined whether the recording position is appropriate. For example, when the QR code is rotated into 90 degrees or 180 degrees and captured in an image, the calculated center coordinates may be corrected to calculate the center coordinates in a non-rotated state. With such a configuration, the article 7 conveyed along the conveyance path
Even if the direction of 1 is not constant, it can be determined whether or not the information code is recorded at an appropriate position of the article.

(2) Although the QR code is used in the above embodiment, the present invention is similarly applied to two-dimensional codes and bar codes 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 using a photo sensor, and detects that the article 71 has reached the position α (see FIG. 2) based on the reflected light from the article 71. Was.

Instead of the article detecting unit 20, a special ink detecting unit may be integrally formed with the optical information reading unit 10. In that case, the special ink is applied to the article 71 in advance. For example, as shown in FIG. The special ink is a so-called magnetic ink or an ink that modulates and reflects light having a predetermined wavelength. Such specialty inks are usually invisible to the human eye because they absorb visible light. Therefore, as shown in FIG. 9, it is conceivable to apply the QR code on the QR code. Then, the special ink sensing unit irradiates the special ink applied to the article 71 with light of 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 used as a relative position from the position where the special ink is applied (for example, the application position indicated by an arrow in FIG. 9). May be calculated. (5) Further, as shown in FIG.
0, a special ink sensing unit 21, and an optical information reading unit 10 may be adopted. At this time,
The units 10, 20, 21 are integrated so that their positional relationship does not change. If such an integrated configuration is adopted, each unit 1
This is advantageous in that dimensional errors 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 sensing 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 that you have come.

In this way, the article detection unit 20
The conveyance speed of the article 71 can also be calculated based on the time when the article 71 is detected and the time when the article 71 is detected by the special ink sensing unit 21. Further, the recording position of the QR code can be calculated based on the time when the article 71 is detected by the special ink sensing unit 21. Accordingly, both the units 20, 2 of the article detection unit 20 and the special ink detection unit 21
If the recording position of the QR code is calculated based on each detection time point of the article 71 by No. 1, the recording position of the QR code can be calculated more accurately.

[Brief description of the 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 as viewed from a direction indicated by a symbol K in FIG.

FIG. 3 is a block diagram illustrating a schematic configuration of a two-dimensional code reader according to the 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 a position of a QR code recorded on an upper surface of an article.

FIG. 6 is a flowchart illustrating a reading process performed by the two-dimensional code reading device.

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

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

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

FIG. 10 is an explanatory diagram illustrating a configuration of a two-dimensional code reader according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Two-dimensional code reader 10 ... Optical information reading unit 10a ... Reading port 11 ... Control circuit 12 ... Light-emitting diode part for illumination 13 ... CCD
Area sensor 14 Amplification circuit 15 Binarization circuit 16 Specific ratio detection circuit 17 Synchronous 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 surface 71b, 71c: End surface

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2F065 AA03 AA17 AA56 BB02 BB15 BB28 CC00 FF04 GG07 JJ03 JJ26 QQ04 QQ24 QQ26 QQ31 SS09 2F069 AA03 AA13 AA64 BB36 BB40 DD16 GG04 GG07 A03 DA07 NN

Claims (10)

[Claims] 1. A detecting means for detecting that an article moving on a transport path has arrived at a predetermined position on the transport path, a light emitting means for emitting light to a code recording surface of the article, and the article by the detecting means After a lapse of a predetermined time from the point in time when it is detected that the object has come to the predetermined position, based on the reflected light of the light emitted by the light emitting means, an image for capturing the information code recorded on the code recording surface of the article as an image Capturing means, based on the image captured by the image capturing means, position information calculating means for calculating position information capable of specifying an area where the information code exists in the image, and position information calculating means. Based on the location information calculated
A code recording position calculating means for calculating a recording position of the information code with respect to the article in at least the transport direction. 2. The recording position detecting device according to claim 1, further comprising a step of determining whether the information code is recorded at an appropriate position of the article based on the recording position calculated by the code recording position calculating means. An information code recording position detecting device, comprising: a code recording position judging means for judging whether or not the information is recorded. 3. A recording position detecting apparatus according to claim 1, wherein said position information calculating means calculates said position information based on a positioning symbol included in said information code. Recording position detection device. 4. The recording position detecting apparatus according to claim 3, wherein said information code is a QR code, and said position information calculation means calculates a center coordinate of a positioning symbol of the QR code as said position information. An information code recording position detecting device, wherein the information is calculated as: 5. The recording position detecting device according to claim 3, further comprising a direction judging unit for judging the direction of the information code in the image based on a positioning symbol included in the information code. An information code recording position detecting device, wherein the code recording position calculating means calculates the recording position in accordance with a result of the determination by the direction determining means. 6. The recording position detecting device according to claim 1, wherein said image capturing means is provided with a plurality of different times as said predetermined time. The image is captured at a plurality of points in time when the predetermined time has elapsed from the point in time when the article is detected to have arrived at the predetermined position, and the position information calculating means determines a position with respect to each of the plurality of images. An information code recording position detecting device, wherein information is calculated, and 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. A recording position detecting device for an information code, wherein the recording position is calculated as the recording position. 8. The recording position detecting device according to claim 6, 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 transport speed of the article which can be calculated based on position information for the same information code, wherein the recording position of the information code is calculated. Detection device. 9. A recording position detecting apparatus according to claim 1, wherein the information code in the image captured by the image capturing means is decoded, and the information code is recorded as the information code. An optical information reading device comprising: decoding means for reading information. 10. A recording position detecting apparatus according to claim 2, wherein the information code in the image fetched by the image fetching means is decoded and recorded as the information code. Decoding means for reading information, wherein the decoding means performs the decoding process only when the code recording position determining means determines that the information code is recorded at an appropriate position on the article. An optical information reading apparatus, comprising: