JPS61278990A - Code reader - Google Patents

Abstract

PURPOSE:To read out a code surely and precisely even if distortion or an error in size exists by collating the code reading data of a circle set up on a picture, and if dissidence is decided, moving the center point of the circle and reexecuting the collation of data. CONSTITUTION:The luminance distribution of the bottom of a bottle is picked up by a TV camera 22 and the image is stored in an image memory 29. A code reading circuit 31 sets up the 1st circle R1 having a prescribed radius around the 1st center point, reading out picture element data along the circle R1 from the image memory 29 and sends the read data to a code deciding circuit to read out the code. When the image of the bottle bottom is sheared in position due to the distortion or positional shear of the bottle and the code reading is unsuitable, the 2nd circle R2 having a radius different from that of the 1st circle R1 is set up and code reading processing is executed on the basis of picture element data along the 2nd circle R2. When the image of the bottle bottom is sheared in position, the 2nd center point is set up, the 1st circle R1 is set up again and the code is read out on the basis of the picture element data along the 1st circle R1.

Description

Detailed Description of the Invention <Technical Field of the Invention> The present invention is a technology applied to a bottle inspection device for inspecting defects in bottles formed by a bottle molding machine, for example. The present invention relates to a code reading device that reads a code indicating a molding location on a bottle bottom to determine the molding location of a defective bottle.

<Background of the Invention> A bottle molding machine is generally equipped with a large number of molds, and these molds are used to simultaneously mold a large number of bottles. After the molded bottles are cooled, they are inspected for various defects using a bottle inspection device, but in order to investigate the cause of defects in bottles, it is necessary to know which mold was used to mold them. Conventionally, a series of investigations of this type have been carried out entirely manually, which has led to the problem of extremely low work efficiency.

Therefore, in recent years, during bottle molding, binary codes representing the mold number are arranged in a circle with protrusions on the bottom of the bottle, and when a defective bottle occurs, the code attached to the bottle can be read.
A method was proposed to identify the mold that produced the defective bottle.

When implementing this method, for example, the code is read from the bottom of the bottle while the bottle is rotated or stopped by shining light through the mouth of the bottle. If there is an error in the code or a positional shift occurs between the bottle and the reading unit, there are problems such as the code becoming impossible to read or reading errors occurring frequently.

<Object of the invention> This invention is intended to solve the above problems,
It is an object of the present invention to provide a code reading device that can read codes reliably and accurately.

<Structure and Effects of the Invention> In order to achieve the above object, the present invention provides a device for reading and discriminating binary codes arranged in a circle.
A code reading device is constituted by an imaging section for capturing an image of the entire part in which the base code is expressed, and a code discriminating section for inputting the image obtained by the imaging section and reading and discriminating the code, and the code discriminating section means for setting two or more circles with different diameters on the image, means for reading image configuration data along each circle to determine the binary code, and comparing the code reading data each time. The apparatus includes means for determining whether or not the data match, and means for moving the center point of the circle based on the determination of the discrepancy and re-reading the image data along the set circle.

According to this invention, the data is adopted only when the code reading data for each set circle matches, and in addition, when the data does not match, the center point of the circle is moved and data reading is performed again. Therefore, if there is distortion or dimensional error in the molded bottle, or if there is a misalignment between the bottle and the reading unit, there is a risk that the code will not be readable or a reading error will occur. This has the remarkable effect of achieving the object of the invention, such as making it possible to read codes reliably and accurately.

<Description of Embodiments> FIG. 1 shows the overall configuration of a bottle inspection device 1 incorporating a code reading device of the present invention.

The illustrated bottle inspection device 1 is provided in the middle of a bottle conveyance path 2, and upstream of this bottle conveyance path 2, a bottle forming machine (not shown) is installed.
is located. The bottle molding machine uses a large number of molds to mold a large number of bottles 50 at the same time. During bottle molding, a code indicating the molding mold is formed on the bottom of the bottle, and by reading the code, defective bottles can be detected. It is now possible to determine which mold was used to mold the product.

The code is a multi-bit binary code, and is formed by integrally protruding a plurality of projections 3 on the bottom of the bottle and arranging them in a circle at a predetermined radius position r, as shown in FIG. . In the illustrated example, the circumference is divided into 16 equal parts, and the positions marked ■ to ■ in the figure are code constituent bits, the positions marked ■ are parity bits, the positions a to d are start bits, S, to The position of S3 is assigned to each reference bit.

The code configuration bits from ■ to ■ correspond to "1" for the presence of protrusions and "0" for no protrusions, so these 8 bits allow a total of 256 types of codes to be set according to the mold number. ing.

The parity bit (2) is used to determine whether the code is correct or not, so that the sum of the "1" bits of (2) to (2) is an even number. The start bit of a”-d is always “0”,
Further, the reference bits S and -S3 are always "1" and are used for detecting the reading start position.

Although each protrusion 3 in this embodiment is long in the radial direction and has a mountain-shaped cross section (see Fig. 3), it is not limited to this, and may be formed in other shapes (for example, hemispherical). good. In addition, in the case of the illustrated example, the inclination angle (
If the slope of protrusion 3 is a curved surface, the maximum tangent angle) is 3
The angle is set to 8 degrees or less so that light from below is effectively reflected downward and also transmitted upward. This allows for reading the code on the bottom of the bottle at the lower position and for reading the code at the upper position. This allows for inspection of the bottom of the bottle (for example, inspection to detect bubbles, bubbles, and foreign matter on the bottom of the bottle) at the same time.

The bottle inspection device 1 includes a feed mechanism 6 that intermittently rotates a star wheel 5 having a plurality of recesses 4 on its circumferential surface, and a feed mechanism 6 provided at each stopping position W of the recesses 4 (hereinafter referred to as an "inspection station"). It consists of a bottle inspection machine (not shown).
Upstream of the feeding mechanism 6, a feeding mechanism 8 having a screw mechanism 7 for feeding the bottles 50 into each recess 4 is provided, and downstream of the feeding mechanism 6, a screw mechanism 8 for collecting defective bottles is provided. A table 9 is provided.

In the illustrated example, there are five inspection stations indicated by A-E in the figure, and four of these inspection stations A-D are equipped with a bottle rotation mechanism 10 to inspect the bottle 50 in a rotating state. However, at the last inspection station E, the bottle 50 is inspected in a stationary state. Each bottle rotation mechanism 10 presses a rotating roller 11 against the circumferential surface of a bottle 50 located at an inspection station to rotate the bottle by the frictional force. Between each inspection station, the bottle is moved to the next inspection station. A guide plate 12 is provided to guide the user.

The final inspection station E is equipped with a code reading device 13 for reading the code on the bottom of the bottle. As shown in FIG. 4, this code reading device 13 is disposed below a support plate 14 that supports the bottom of the bottle 50, and in the empty space above the support plate 14, for example, the height of the bottle, the height of the bottle, An inspection machine 15 is installed to inspect the caliber, smoothness of the bottle mouth, defects in the bottom of the bottle, etc., in order to make effective use of space.

The support plate 14 has a structure in which a resin plate 17 is stacked on a metal substrate 16, and the metal substrate 16 has a notch 18 corresponding to the position of the bottle, and the resin plate 17 has a taber that opens downward. Holes 19 are provided respectively.

The code reading device 13 includes a ring-shaped light source 20 for projecting light onto the bottom of the bottle to effectively illuminate only the protrusion 3;
A case 21 for storing 0, a television camera 22 for taking an image of the bottle bottom, which is placed inside the case 21 facing toward the bottom of the bottle, and the image obtained by this television camera 22 is input to read the code. It is composed of a code discrimination circuit 23 for discrimination.

The ring-shaped light source 20 includes two ring-shaped fluorescent lamps 24.
25 are arranged vertically in parallel, and the electrode portions of the fluorescent lamps that do not emit light are positioned diagonally to prevent uneven light projection onto the bottom of the bottle. The case 21 that houses the fluorescent lamp 24°25 is the housing 2
6 and a diffuser plate 27 that covers the inside and upper side of the light source 20, and a transparent resin plate 28 is placed on the upper surface of this diffuser plate 27.
is in place.

FIG. 5 shows an example of the configuration of the code discrimination circuit 23. In the figure, a television camera 22 images the bottom of the bottle, converts it into an image, and stores this image in an image memory 29. As shown in FIG. 6, the illustrated image memory 29 has a large number of pixels of 256 bits each in the vertical and horizontal directions, and each pixel stores pixel data having a brightness level corresponding to the image. Image memory 29
A monitor television 30 and a code reading circuit 31 are connected to the monitor television 3o, so that the images stored in the image memory 29 can be visually checked through the monitor television 3o.

The code reading circuit 31 reads each pixel data of the image stored in the image memory 29, performs processing such as binarization, and then reads the code data. This code reading circuit 31 is a CPU of a personal computer 32.
(Central Processing Unit)
33, and the CPU 33 executes various processes while controlling the operation of the code reading circuit 31 based on the program in the memory 34, and also controls a series of operations from code reading to discrimination. It is.

FIG. 7 shows a specific circuit configuration of the code reading circuit 31. The code reading circuit 31 in the illustrated example has a circle (broken lines RI, R2 in FIG. 6) for reading the code on the image memory 29.
), and a circuit unit 31A for sequentially specifying the XY coordinates of pixels located on this circle, and binarizing the pixel data read from the specified coordinate position on the image memory 29. Circuit section 31 for processing and reading codes
B, and each circuit section 31A.

31B are each connected to the image memory 29 via an interface 35.

The circuit unit 31A has a function of setting multiple types of circles with different diameters and center points on the image memory 29, and has XY coordinate data (in this embodiment, one day A pair of ROMs (Read only 360 pieces of coordinate data per piece of information)
Memory) 36.

37, a brisset counter 38 that sequentially counts the addresses of each ROM 36 and 37 and outputs XY coordinate data, and an adder 39 that moves the center point of the circle by a predetermined coordinate.
40.

FIG. 8 shows n types of day information FI-F with different diameters stored in each of the ROMs 36 and 37, and when any of these day information is designated with the keyboard of the personal computer 32, the preset counter On the 3rd, the start address of that day's information is preset.

FIG. 9 shows that when reading the code, the center point of the mouth is
Number 1, 2, 3. . . . (details will be described later), and this order and movement coordinate distance are automatically set by the personal computer 38.

The circuit section 31B includes a launch circuit 41 for holding pixel data read out from the image memory 29, and a comparator for comparing each latched pixel data with a predetermined threshold value and binarizing it. 42, a gate signal generation circuit 43 that forms 16 gate signals necessary for extracting a 16-bit code, and a binarized output from the comparator 42 using the gate signal provided from the gate signal generation circuit 43. a code determination circuit 44 that reads, determines and extracts the code; and a shift register 4 that holds 16 bits of the output of the code determination circuit 44 and outputs it to the microcomputer 32.
5.

FIG. 10 is a diagram continuously showing pixel data on a circle read out from the image memory 29, where the horizontal axis shows the angle and the vertical axis shows the brightness level.

In the figure, parts with high brightness levels correspond to protruding parts on the bottom of the bottle, and by comparing this pixel data with a predetermined threshold value TH in the comparator 42, a code as shown in FIG. 11 is obtained. Obtain the pulse signal that makes up the .

The gate signal generation circuit 43 includes an edge/edge detection circuit 46 that detects the edge portion e-t of the first pulse signal shown in FIG. Then, the first gate 4 generates a gate signal G8 (where i is an odd number) of 22.5 degrees, and one gate width is 22 degrees and the other gate width is 23 degrees.
7 and a gate signal G with a gate width corresponding to an angle of 23 degrees.
, (where j is an even number), and a gate distribution circuit 49 that alternately supplies gate signals to the sign determination circuit 44, and the gate distribution circuit 49 detects the edge portion e. Then, after a predetermined period of time has elapsed, the distribution starts operating.

Thus, the sign determination circuit 44 receives the logic “1” from the comparator 42.
The sign is determined based on whether or not a specified number of signals exist in the gate, and as a result, 16-bit data is output bit serially, and this data is once called into the shift register 45. Thereafter, it is taken into the microcomputer 32.

FIG. 12 shows the control flow of code reading and discrimination operations of this microcomputer 32, and FIG.
In FIG. 12, the initial setting operation of step 1 (indicated as rSTIJ in the figure) is shown.

Prior to the bottle inspection, when an initial setting button provided at a suitable location of the device is turned on, a predetermined lamp lights up to notify the start of the initialization process (steps 101 and 102). Next, the image of the bottle bottom (for example, the image of the model for initialization) stored in the image memory 29 by the television camera 22 is
The image is captured and displayed on the monitor television 30 (step 103). Then, in the next step 104, when any circle information is selected and the radius of the circle is input and specified,
As shown in FIG. 6, the CPU 33 draws a circle (for example, R1) on the image memory 29 centered on the center point P, and this circle is displayed on the monitor television 30 together with the image (
Step 105). The image in the image memory 29 is taken into the monitor television 30 at regular intervals (for example, 1 second), and the screen display is updated. If the position of the circular array image is shifted, adjust the position of the television camera 22 while looking at this screen.

When the above-mentioned adjustments on the screen are completed and the initial setting button is turned off, the answer to step 106 becomes "YES", the lamp goes out, and the apparatus waits for the start of the examination.

When the bottle inspection operation is thus started and the bottles 50 are sent from the bottle transport path 2 to each concave portion 4 of the star wheel 5, the bottles 50 are sequentially sent to inspection stations A to E by the intermittent rotating operation of the feeding mechanism 6. A predetermined inspection is carried out each time. When the bottle 50 reaches the final inspection station E and the inspection timing signal is input to the CPU 33, "YES" is determined in step 2, and the code reading device 13 is activated in the next step 3.

If uniform light from the ring-shaped light source 20 passes through the diffuser plate 27 is irradiated uniformly onto the bottom surface of the bottle 50 that is stationary at the inspection station E, the light hitting the protrusion 3 on the bottom of the bottle will be reflected. As a result, only the protrusion 3 shines brightly, and the other parts become dark.

The brightness distribution at the bottom of the bottle is immediately imaged by the television camera 22, the image is stored in the image memory 29, and the code is read by the code reading circuit 31. In this code reading circuit 31, first, a first circle R1 (shown in FIG. 6) having a predetermined radius with the first center point (see FIG. 9) as the center of the circle is set, and The successive output of pixel data and further reading are performed by hardware.

First, a predetermined preset counter value is given to the preset counter 38, and as a result, 360 XY coordinate data for setting the first circle R1 are sequentially transferred from the corresponding address of each ROM 36, 37 as the counter 38 performs a counting operation. Read out. The outputs of the ROMs 36 and 37 and the center point correction value data from the CPU 33 are input to each of the following adders 39 and 40, and addition processing is performed. In the figure, since point P) is set, each correction value is "zero J."

In this way, pixel data is sequentially read out from the corresponding pixels of the image memory 29 based on the XY coordinate data outputted by each adder 39 and 40 and sent to the latch circuit 41. Next, these pixel data are binarized by a comparator 42 and sent to a sign determination circuit 44. Furthermore, this sign determination circuit 44 is given a gate signal generated by a gate signal generation circuit 43. The code is read. As a result, if the reading is performed properly, the determination in the next step 4 becomes "YES", and the shift register 4 goes to CP1, 133.
5 to 16 bits of read data is transferred, and this transferred data is set in the memory 34 (step 5).

If the image of the bottom of the bottle is misaligned with respect to the circle R due to bottle distortion or misalignment of the bottle, one pulse signal may be detected across two gates, etc. , the judgment in step 4, ``Is reading appropriate?J'' is NO'', and the process proceeds to step 11.

Regarding the transfer data in step 5, next the CPU 3
3, in step 6, it is determined whether there is data corresponding to the start bits at positions a to d in FIG.
In the next step 7, it is determined whether there is data corresponding to the reference bit at position S+-53 in FIG. 2, and in step 8, whether the parity based on the parity bit at position ■ in FIG. Each is checked to see if it is not. As a result, all of steps 6 to 8 are “YE”.
If the result is "S", the process advances to step 9, where it is checked whether or not this data reading is the second time.In this case, the determination is "No", so the process advances to step 10.In step 10, the A second circle R2 having a different diameter from the first circle R2 is set at the same center point as above, and that circle R
A second code reading process is executed by the code reading circuit 31 based on the pixel data along the lines 2 and 2. That is, in the code reading circuit 31, a preset value different from the previous one is given to the preset counter 38, so that each ROM
36. ．． 37 corresponding address to said second circle R2
360 x and y coordinate data for setting are read out one after another along with the counting operation of the counter 38 and given to the image memory 29.Hereinafter, reading of pixel data from the image memory 29, binarization processing, and code determination will be described. Each operation is performed in the same manner as described above.

On the other hand, if the bottle is distorted or the bottle is misaligned,
In the case where there is a positional shift of the bottle bottom image with respect to the first circle R5, any judgment in steps 4.6 to 8 is "No".
When , the process proceeds to step 11, where the second center point (see FIG. 9) is set. And then step 1
2, "Have all center points been set?" is NOl, so in step 13, the first circle R with the same radius as above
, is reset, and the code is read again based on the pixel data along the circle R5. In this case, the code reading circuit 3
1, to set the second center point, CP
Center point correction value data ΔY is added from U33 to adder 39.40
As a result, pixel data is read out on the image memory 29 along a circle having the point P as the center point in FIG.

(The second code reading process based on the second circle R2 is performed, and if the reading is performed properly, the determination in step 4 becomes "YES" and the code reading circuit 31 The read data of 16 bits is transferred to the CPU 33 and stored in the memory 34.Then, the CPU 33 performs the checks in steps 6 to 8, and if all of the results in steps 6 to 8 are "YES", further steps are performed. Step 9
will be checked. In this case, the determination of "Is this the second reading?" in step 9 is also "YES", so the process proceeds to step 14, where it is determined whether the first read data and the second read data match. be done. As a result, when the determination in step 14 is "YES", it is determined that the read data is appropriate, and the CPU 33 reads the code using the position of the start bit as a clue, and transmits the reading result to, for example, a host controller ( output to the bottle inspection device controller).

On the other hand, if the determination in any one of steps 4.6 to 8.14 is "NO1", the next center point is set in step 11, and the same process is repeatedly executed.

In the example of FIG. 9, if proper data is not obtained even after setting the center point 57 times, the determination in step 12 will be "YES" and error processing will be performed in step 16. .

By reading the code above, it is possible to know the mold number of the bottle molding machine that molded each bottle 50, and by automatically tallying up the correspondence between bottle defective locations and mold numbers, the defective locations can be traced. and its corrections can be made quickly and appropriately.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of the overall configuration of the bottle inspection device, Fig. 2 is an explanatory drawing showing the symbols attached to the bottom of the bottle, and Fig. 3 is Fig. 2 n.
4 is a longitudinal sectional view showing an example of the configuration of the code reading device, FIG. 5 is a block diagram showing an example of the circuit configuration of the code reading device, and FIG. 6 is a storage of the image memory. Figure 7 is a block diagram showing a specific example of the code reading circuit. Figure 8 is a diagram explaining the contents of the ROM in the code reading circuit. Figure 9 is a diagram showing the setting of the center point. FIG. 10 is a diagram showing pixel data read out from the image memory; FIG. 11 is a diagram showing the timing of the code reading operation; FIG. 12 is a flowchart showing the control flow of the code reading operation; The figure is a flowchart showing the flow of initialization processing. 13... Code reading device 22... Television camera 23... Code discrimination circuit 31...
... Code reading circuit 32 ... Personal computer 33 ... CPU 34.
...Memory 38...Preset counters 36, 37...ROM 39.40...
... Adder patent applicant Yamamura Glass Co., Ltd. agent Patent attorney Mitsugaku Suzuki 70 drawings! ,・-Ha shows the master and the fisherman, the city shows the city, the figure is shown, and the figure is 6 stores. 2I circuit, professional,
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Claims (4)

[Claims] (1) A device that reads and discriminates binary codes arranged in a circle, which includes an imaging section for capturing an image of the entire area where the binary code is expressed, and an image obtained by the imaging section is input. and a code discriminating unit that reads and discriminates the code using the image, and the code discriminating unit includes means for setting two or more circles with different diameters on the image, and a means for setting two or more circles with different diameters on the image, and a means for reading the image configuration data along each circle and converting the image into binary data. a means for determining the code; a means for comparing the code reading data for each circle to determine whether or not the data match; and means for re-performing the reading. (2) The code reading device according to claim 1, wherein the binary code is constituted by presence or absence of protrusions protruding from circular positions on the surface of the object. (3) The code reading device according to claim 1, wherein the imaging unit is a television camera. (4) The code reading device according to claim 1, wherein the code discrimination section includes a computer circuit in its configuration.