JPS62106348A - Apparatus for inspecting transparent or translucent sphere - Google Patents

Abstract

PURPOSE:To automatically detect the crack of the nucleus of a pearl, by converting the video signal received by two TV cameras by an A/D converter and operating the difference of adjacent frames and obtaining the judge output of inferiority when the contrast change thereof exceeded a set value. CONSTITUTION:A video signal received by a ITV camera having an image sensor is converted by an A/D converter 231 and the signal ed corresponding to an odd number frame is stored in a frame memory 234 through a switch circuit 232 and the signal ed corresponding to an even number frame is stored in a frame memory 235 through said switch circuit 232. The adjacent address informations of the frame memories are compared by an operation circuit 237 and the difference between said informations is operated and the signal ei corresponding to the contrast change on adjacent points is outputted to a control circuit 18. In the circuit 18, the set value es from a judge reference setting circuit 182 is compared with the output of the circuit 237 by a comparing means 181 and a signal e0 is supplied to an output means 183 to output a control signal C6 to an assortment circuit assoring a good product and an inferior product. In the same way, the crack of a pearl nucleus is inspected with high accuracy by a ITV camera to simultaneously inspect the same pearl nucleus at an angle crossing the camera 12 at a right angle.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Field The present invention relates to an inspection device that automatically inspects and sorts cracks on the surface of transparent or translucent spheres, such as pearl nuclei or pearls.

<Prior art> If there are minute cracks on the surface of the nacre, the pearl substance attached to the surface is extremely thin, so four parts corresponding to the cracks on the surface of the nacre will appear on the formed pearl surface, and the resulting pearl will The 1IlIi value of 1IlIi will drop significantly. For this reason, when inspecting the surface of pearl nuclei, skilled inspectors pick them up one by one and visually determine the presence or absence of cracks.

<Problems to be Solved by the Invention> However, such human inspection means have problems in that the inspection speed is slow and the inspection results vary widely.

Furthermore, since the cracks to be inspected are very small, the inspector's eyes are subject to severe fatigue, which poses health problems.

An object of the present invention is to provide an inspection device for transparent or semitransparent spheres that can solve the above problems and automatically inspect minute cracks.

Means for Solving Problems> The first structural feature of the present invention is a light projecting means that divides the surface of a transparent or semitransparent sphere to be inspected into a plurality of frames and projects light; image sensor means for receiving each frame of transmitted light from the sphere to be inspected; frame memory means for temporarily storing the contrast output of the image sensor; calculation means for detecting adjacent contrast changes in each frame; The present invention is provided with comparison means for comparing the output from the calculation means and the set value.
Furthermore, a second feature is a sorting means for sorting the spheres to be inspected into non-defective products and defective ones based on the output of the comparison means, and a means for projecting and sorting the spheres to be inspected which are sequentially inputted from the inputting means. The present invention is characterized in that it is equipped with a transport means for transporting the equipment to the installation location, a control means having a processor for controlling the above-mentioned means in an integrated manner, and a man-machine interface means for exchanging information with the control means.

<Operation> According to the present invention, the spherical body to be inspected is divided into a plurality of frames, and the contrast of each frame is stored in a frame memory via an image sensor that receives transmitted light from the light projecting means. The contrast is compared with a set value, and based on the comparison results, good and defective products are automatically determined and sorted.

<Embodiment> Hereinafter, an embodiment of the present invention applied to a pearl nucleus inspection device will be described with reference to FIGS. 1 to 6.

Fig. 1 is a side view of the inspection device, Fig. 2 (A) is a plan view,
(B) is a bottom view, with some components omitted. 1 is a hopper that stores pearl nuclei 2 having the same diameter for 10 tons to be inspected, and 3 is a disk-shaped fixed table 5 through which pearl nuclei 2 are fed one by one via a feeder 4 each time a control signal @C+ is supplied. It is an immersive means that is inserted into the peripheral part of the body.

Reference numeral 6 denotes a turntable forming a conveying means, which is arranged concentrically close to the upper surface of the fixed table 5, and has a rotating means 7 such as a pulse motor driven by a control signal C2.
It is rotated at a constant speed in the six directions indicated by the arrows.

Reference numeral 601 denotes a plurality of holding holes for pearl nuclei formed at regular angles on the periphery of the turntable 6, and the discharge port of the feeder 4 corresponds to the upper part of this holding hole. At the timing of rotation to the lower part of the discharge port, the charging means 3 is driven and one pearl kernel is charged onto the fixed table 5 through this holding hole.

The inserted pearl kernels 2 are slid on the fixed table 5 by the turntable 6 and passed through the charging means 3 and the light projecting means P.
On the side, a notch 501 is formed in the fixed table 5 in the diametrical direction, and a transparent plate 8 for holding the transported pearl nucleus is placed in this notch. This transparent plate 8 is linked to an X stage 9 and a Y stage 10 that are driven in mutually orthogonal directions by control signals C3 and C4, and can move within a certain range in the directions indicated by arrows X and Y within the cutout portion 501. That's it. Therefore, the pearl nucleus 2 on this transparent plate is rotated within the holding hole by the movement of the transparent plate 8 in the X and Y directions.

A strobe light 11 driven by a control signal c5 is arranged below the transparent plate 8, and light from this strobe light passes through the transparent plate 8 and the pearl nucleus 2 in the holding hole. Transmitted light L+.

L2 is an ITV camera 1 having a CCD image sensor
The light is received by 2.13.

With such a structure of the light projecting means, it is possible to divide a part or the entire surface of the pearl nucleus 2 into a plurality of frames and inspect transmitted light for each frame.

The two ITV cameras 11 and 12 receive transmitted light L+ and 12 light with orthogonal polarities. This is essentially 1
A single camera can be used, but in order to avoid measurement errors due to the directionality of the crack and highlight the characteristics of the crack, the outputs of the two cameras can be processed simultaneously to create a measurement signal.
Improves reliability.

Based on the light reception signal from the ITV camera, the pearls are compared with a certain standard through simulated signal processing to check for cracks in the pearl core and determine whether the pearl is good or defective.

14 is a sorting means driven by a control signal C6, which is arranged at the lower part of a drop hole 502 formed in the fixed table 5 on the downstream side of the light projecting means P, and is used to sort pearl nuclei 2 falling from the drop hole. Based on the above judgment result, the products are sorted into a non-defective product discharge duct 15 or a defective product discharge duct 16.

FIG. 3 shows an enlarged configuration diagram of this sorting means, and the pearl nuclei 2 that have fallen down the drop hole 502 in the direction of the arrow are sorted into positions not shown by solid lines due to the angular position of the direction operation plate 141 of the means 14. When the position is operated to the position indicated by the dotted line 141', the pearl kernels are controlled to be discharged to the non-defective product discharge duct 15 side, and when the position is operated to the position shown by the dotted line 141', the pearl kernels are controlled to be discharged to the defective product discharge duct 16 side.

4 is formed on the turntable 6? ! This is an enlarged configuration diagram of the hold hole 601, and the peripheral edge 602 of the hole has r! A bushing made of resin material 17 with a small J111 coefficient is attached to smooth the rotational movement of the pearl nucleus.

The size of the hold hole 601 is determined by the diameter of the loft to be inspected (
2mm to 13mm>, it is necessary to configure the attachment and replace the attachment in advance according to the diameter of the lot automatically or manually (1).Please note that the attachment is not replaced. A configuration in which the turntable is replaced may also be used.

Next, the overall system configuration will be explained with reference to FIG. Reference numeral 18 denotes a control means for controlling the sequence and judgment of each of the above-mentioned means, and is realized by a combi coater means having a microprocessor.

One is a CRT display, 20 is a keyboard, and 21 is a printer, which form a man-machine interface means for exchanging information between the control means 18 and the operator.

The control means 18 supplies a control signal CI to the loading means 3 and a control signal C6 to the sorting means, and also supplies a control signal C2 to the rotation means 7 for driving the turntable via the controller 22, and supplies a control signal C2 to the rotation means 7 for driving the turntable.
Control signals C3 and C4 are supplied to the strobe light 11, and a control signal C5 is supplied to the strobe light 11.

23 is a video signal processing section that processes the light reception signal of the rTV camera 12, and 24 is a video signal processing section that processes the light reception signal of the ITV camera 13. The processing information of each video signal processing section is given to the control means 18, and a judgment is made as to whether the product is good or defective.

Control means 18 and machine interface means 19
.

Next, with reference to FIGS. 6 to 8, an embodiment of a signal processing means for determining good products and defective products based on light reception information will be described.

FIG. 6 is a signal processing system diagram, and for simplicity, only the system of one ITV camera 12 is shown.

The ITV camera consists of CCD image sensor means,
The transmitted light information of each frame is temporarily stored, converted into serial information ea, and transmitted.

In the video signal processing section 23, 231 is an analog-to-digital converter that converts the signal ea into a digital signal ed, and 232 is a switching device that switches the signal ed every frame and alternately supplies the signal ed to a pair of frame memories 234 and 235. , 236 is frame memory 2
The contents of 34 and 235 are alternately switched and the sieving means 2
37, the switch means 23
It is controlled in reverse phase in synchronization with 2. Therefore, in the phase in which the signal ed is read into the frame memory 234 via the switch means 232 as shown in the figure, the contents of the frame memory 235 storing the frame information of the previous frame are calculated via the switch means 236. It is output to means 237. In the phase in which the next frame signal ed is read, this relationship is reversed, and thereafter such alternate reading and output are repeated. Note that 238 is the frame memory 23
This is an address counter for 4.235 addresses.

With such a frame memory configuration, if frames are numbered, the frame memory 234 stores a signal ed corresponding to an odd numbered frame, and the frame memory 235 stores a signal ed corresponding to an odd numbered frame.
A signal ed corresponding to an even frame is stored in , and information on all frames to be inspected is sequentially outputted to the calculation means 237 side.

The calculation means 237 compares the information of adjacent addresses in each frame memory and calculates the difference between the two. Therefore, the output eL obtained from this calculation (q) corresponds to the contrast change on each adjacent point in each frame.

The control means 18 includes a comparison means 181 that receives a signal eL from the video signal processing unit 23 corresponding to the contrast change of each frame, a determination criterion setting means 182 that supplies a set value es to this comparison means, and a comparison means 182 that supplies a set value es to the comparison means. Means 1 is used for sorting to sort into good and defective products based on the comparison output eo.
4 has the function of an output means 183 for transmitting a control signal C6. Note that the set value es can be arbitrarily set from the man-machine interface means, and is configured so that the criteria for judgment can be controlled depending on the lot.

With such a configuration, it is possible to obtain a defect judgment output when the adjacent contrast change exceeds a set value in each frame.

Next, contrast changes due to cracks in the pearl nucleus and contrast changes due to surface patterns will be explained. Figure 7 (A> shows the pearl nucleus 2 with cracks, and shows the dark part due to the crack. This dark part is included in A of the right frame Fa.
-A' is scanned and the level change of the image signal ea is the 8th
As shown in Figure (A), the signal level at the boundary of the crack decreases rapidly, and the rate of change α is large. This rate of change α corresponds to the contrast change.

On the other hand, FIG. 7(B) shows a pearl nucleus 2 having a pattern on its surface, and M is a dark area caused by the pattern.

The image signal ea obtained by scanning the line BB' of the frame Fb including this dark area has a level change as shown in FIG. 8(B). In this case, the rate of change β of the boundary portion of the pattern is smaller than the rate of change α due to cracks.

Therefore, by selecting the value of the set value es to be smaller than the output signal eL of the calculation means corresponding to the rate of change α and larger than the output signal eL corresponding to the rate of change β, it is possible to apply only to dark areas with only cracks. It becomes possible to determine whether the product is defective, and malfunctions due to patterns can be avoided.

Note that if a crack is detected in a certain frame, that pearl nucleus is determined to be a defective product at the time of detection, and the determination work for the remaining uninspected frames is stopped.

The above is an explanation of the system of the ITV camera 12.
The system of camera 13 can also have the same configuration, and 2
By calculating the logical sum of the failure judgment outputs of the system and transmitting the control signal C6, it is possible to realize a highly accurate inspection that prevents measurement errors due to the directionality of cracks.

The pearl kernel inspection apparatus described above further uses the man-machine interface means 19 to 21 to manage the defect judgment setting value e5 for each lot number, manage the attachment of the bold hole of the turntable, and manage data on non-defective and defective products. It is possible to manage inspection results over a certain period of time, and it is possible to automate various management and statistical tasks.

In the above embodiment, the present invention is applied to a pearl kernel inspection device, but the present invention can also be applied to produced pearls or transparent or translucent spheres other than pearls to detect scratches such as cracks on the surface. It can be applied to equipment that automatically inspects and sorts items.

In the above embodiment, in the light projecting means P, the method of frame division is shown in which the strobe lamp and the ITV camera are fixed and the sphere to be inspected is rotated. It may also be configured to rotate.

<Effects of the Invention> As explained above, according to the present invention, it is possible to completely automate the inspection of pearl nuclei, which conventionally relied on visual inspection by skilled human eyes, and to inspect pearl nuclei between the rows in a short time. It is possible to carry out inspections with extremely high accuracy, and health problems such as eye fatigue for inspectors are also resolved.

Furthermore, by using processor means, statistical control for each lot, which was conventionally considered a tedious task, can be easily performed by using CRT displays and printer means, and quality control of pre-processes based on management data and defective product control can be performed easily. This also makes it easier to manage the reuse (cutting and using it for products with smaller diameters).

[Brief explanation of drawings]

Fig. 1 is a side view showing an embodiment of the device of the present invention, Fig. 2 is a plan view and a bottom view thereof, Fig. 3 is an enlarged configuration diagram of the sorting means, and Fig. 4 is a view of the hold hole portion of the turntable. Enlarged configuration diagram, Figure 5 is a system configuration diagram of the entire inspection device, Figure 6
The figure is a system diagram of signal processing, and FIGS. 7 and 8 are explanatory diagrams of waveforms of video signals due to cracks and patterns.

Claims (2)

[Claims] (1) A light projection means that divides the surface of a transparent or translucent sphere to be inspected into a plurality of frames and emits light; an image sensor means that receives transmitted light of each frame from the sphere to be inspected; A transparent or transparent device comprising a frame memory means for temporarily storing the contrast output of the image sensor, a calculation means for detecting adjacent contrast changes in each frame, and a comparison means for comparing the output from the calculation means with a set value. Translucent sphere inspection device. (2) a light projection means that divides the surface of a transparent or translucent sphere to be inspected into a plurality of frames and projects light; an image sensor means that receives transmitted light of each frame from the sphere to be inspected; Frame memory means for temporarily storing the contrast output of the image sensor, calculation means for detecting adjacent contrast changes in each frame, comparison means for comparing the output from the calculation means with a set value, and the comparison means a sorting means for sorting the spheres to be inspected into good and defective products based on the output of the input means; a conveying means for transporting the spheres to be inspected, which are sequentially input from the input means, to a location where the light projecting means and the sorting means are installed; and each of the above means. A transparent or translucent spherical inspection device comprising: a control means having a processor for overall control; and a man-machine interface means for exchanging information with the control means.