AU601714B2 - Object inspection apparatus - Google Patents

Description

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APPLICANT:

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FILING DATE: IHAJIME INDUSTRIES )T.TD 00 G 0 00a

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FORM 0000 0 00 00 0 j0 00 0 0 0 COMMONWEALTH OP AUSTRALIA The Patento Act 1952 COMPLETE SPECIFIC2ZTIOW FOR AN INVENTIONI ENIVTtLED: OBJECT INSPECTION APPARATUS The following statement is a ful, description of this inventiont including the best method of per~forming it known to me: 1 1 ABSTRACT OF THE DISCLOSURE An object inspection apparatus having a light source for irradiating an object to be inspected, a pick-up device for picking up the object and generating an image signal thereof including a synchronizing signal, and an inspecting device for receiving the image signal to inspect whether or not the object has a defect, in which the inspecting device includes a reference position detector for generating a reference position signal based upon an image signal in a j first field of the image signal and the synchronizing signal, an inspection zone position setter storing an inspection zone of a predetermined shape and for generating a control signal based on the reference position signal and the synchronizing 'signal, an inspection zone controller receiving the image signal from the pick-up device and the control signal and for delivering an image signal in a second field of the image signal from the pick-up device within an inspection zone determined by the control signal, and a judging device receiving the image signal from the inspection zone controller to judge whether or not the object has a defect.

_0 BACKGROUND OF THE INVENTION Field of the Invention The present invention relates generally to object inspection apparatus and, is directed more particularly to such object inspection apparatus that utilizes a pick-up device such as a video camera to inspect the objects.

Description of the Prior Art Presently, in replacement of the manual object inspections conducted by the human vision as well as hands, such an automatic appearance inspection apparatus of objects has advanced in which a photoelectric conversion sensor is used to pick-up the object and the output signal therefrom is electronically processed. In such case, many apparatuses use a video camera that is formed of a pick-up element such I as. a CCD or the like, to pick-up an object to be inspected by receiving the reflection light emitted therefrom which is irradiated by a light source. Then, a corresponding video signal is processed by an~ exclusive electronic circuitry to conduct the inspection of the object.

As for the inspection items for such appearance inspection apparatus of the object that replaces the human inspection of the object, there are the variety of requirements such as, for example, the shape of the object, its dimension, a flaw on its appearance, foreign particle adhered thereon or mixed therewith, etc..

Further, there is a wide variation in the inspected objects from flat board like objects to cubical objects with severe uneveness, whereby normal1y, the object inspection is not proposed for f*ile entire df~tN object, but the requirements are to conduct a specific inspection that i 4" iO" L_ 1 i i~~uau~uup-.- B™-KW A.>l I limited to a partial area of the object.

For example, in the case where the inspection is purposed to check a crack at the body portion of a transparent glass bottle 1 and a foreign particle mixed Stherein, as shown in Fig. 1, inspection areas or zones 2 and i 3 as shown by the dot lines in Fig. 1 are determined, which J makes only the necessary portions as the subject zones to be inspected, and the image signals from such portions are Selectronically analyzed to thereby detect flaws or=-h- ,-fIt that exist within such above mentioned inspection zones 2 and 3.

Such above mentioned determination of such specific inspection zones 2 and 3 is expressed as providing windows or to conduct masking. Fig. 2 shows one example thereof, whereas reference numeral 4 denote a target screen of the video camera though not shown or the picture screen of a video monitor (not shown) which is connected to the video camera. Within this picture screen 4, such aforementioned specific inspection zones or the windows 2 and 3 are j provided as shown in Fig. 2 and only the areas inside these windows 2 and 3 are made as the subject zones for the inspection of the bottle 1. After providing such windows 2 and 3, if the bottle 1 to be inspected is transported to -come to the position as indicated by the dotted line in Fig.

2 and then picked up by the video comera, the inspection of the necessary portions of the bottle 1, in other words, the inspection of only the windows 2 and 3 will be carried out.

There are various means to provide such windows 2 and 3, for instance, between the vidpo camera and the bottle 1 which is r he inspected object, there is located an opaque plate with t( 3 iiJC -3 3 apertures therethrough that are corresponding to the shapes of windows 2 and 3 to thereby physically provide windows 2 and 3 or means to electronically control the image signal from the video camera by horizontal and vertical coordinates in correspondence with the windows 2 and 3, or to electronically provide windows 2 and 3 by the computor software. In such case, where the windows are provided as above and only the portions within the windows are made as zones to be inspected, it is essential that the inspected object must be picked up at a predetermined exact position.

For such purpose, in the prior art, for example, when the inspected objects are moving on conveyer at the production lines and inspected by this method of inspection using the windows, a separate position detection means must be provided in order to detect whether or not the object that is to be inspected has arrived at such predetermined 1 position. As a practical example, there was needed an arrangement formed of a light projector and a light receiving sensor to detect the position at which the inspected object crosses the light beam from the light projector. Therefore, the system construction becomes complicated which confines the range of application.

OBJECTS AND SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a novel object inspection apparatus.

It is another object of the present invention to provide an object inspection apparatus which is simple in a circuit construction.

It is a further object of the present invention to provide an object inspection apparatus in which an 4

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According to an aspect of the present invention there is provided an object inspection apparatus comprising: a light source for irradiating an object to be inspected; photosensing means for generating an image signal of said object including a synchronizing signal; and inspection means for receiving said image signal to determine whether or not said object has a defect; said inspection means having: reference position detecting means for generating a refee:nce position signal based upon an t« c image signal in a Eirst field of said image signal and w t 15 said synchronizing signal; inspection zone position setting means storing an inspection zone of a predetermined shape and for generating a control signal based on said reference position signal and said synchronizing signal; S 20 inspection zone control means receiving the image signal from said photosensing means and the control signal from said inspection zone position setting means and for delivering an image signal in a second field of said image signal from said photosensing means within said inspection zone determined by said control signal; and T7-7 L 0 judge~meit cizc~ilt means receiving the 1I~mage signal from said inspection zone control means to judge whether or not said object has a defect.

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1: t BRIEF. DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing an inspection zone of an object to be inspected; Fig. 2 is a front view showing the picture screen of a monitor television receiver; Fig, 3 is a block diagram showing an electrical circuitry of a main part of one example according the present invention; Figs. 4 and 5 are schematic diagrams that are used to no expla,n the operation of the present invention; and Figs. 6 and 7 are schematic diagrams respectively oo@ O showing parts of another example of the present invention.

°4 DESCRIPTION OF THE PREFERRED EMBODIMENTS S0 An example of the present invention will be explained in reference with Fig. 3 which is a block diagram showing Sthe example of the present invention. In Fig. 3, reference o4 numeral 5 designates a video camera that is used as a pick-up device which is formed of, for example, a CCD (charge-coupled device) as a photosensing element and picks up an object to be inspected and reference numeral 6 a o, synchronizing signal separator circuit that separates a vertical synchronizing signal V and a horizontal synchronizing signal H from the composite video signal that is delivered from the video camera 5. Reference numeral 7 denotes a reference position detection section which based on the signal in the first field of the image signal of the inspected object from the video camera 5, detects a portion of the image signal in the first field which is previously determined and generates a reference positional signal for a 6 /y i j Ir_; YL~_ 1 i" r un i aao mci o aJ uir a os

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an so window or inspection zone. This reference position detection section 7 is connected to the output sides of the video camera 5 and the synchronizing signal separator circuit 6. Reference numeral 8 represents an inspection zone position setting-up section that receives the output signals from the synchronizing signal separator circuit 6 and the reference position detection section 7 to determine a relative position between the previously determined inspection zone pattern of the object and the image thereof by such reference position signal, and 9 an inspection Ssection which processes the image signal in the second field •O within the inspection zone pattern set up by the position Ssetting-up section 8 to detect the flaw or abnormalities within the inspection zone of the inspected object and to .o deliver the judgement signal to the outside. To this end, the inspection section 9 receives the output signal from the video camera 5 and the output signal from the inspection tf Szone position setting-up section 8. In this case, the separatoe circuit 6, the detection section 7, position setting-up section 8 and the inspection section 9 construe an inspection apparatus 14.

The operation of the aforementioned object inspection apparatus according to the present invention will be explained in reference with Figs. 4 and 5. In Fig. 4, reference numeral 1 designates the inspected object such as a glass bottle or the like as mentioned before, 11 a belt conveyer which transfers the inspected objects 1 in the direction shown by an arrow A and 12 a light source which irradiates light onto the inspected object 1 on the belt conveyer 11 and is located at the opposite side to the video oo ao a

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7 camera 5 with respect to the belt conveyer 11. In this case, the video camera 5 photosenses the light which has passed through the glass bottle 1. Reference numeral 13 denotes a monitor television receiver which displays an image of the glass bottle 1 as picked up by the video camera and 14 is the inspection apparatus whirn includes the I reference position detection section 7 and so on as shown on Fig. 3 and which is construed by an electronic circuitry.

Fig. 5 shows a monitor picture screen 13A of the monitor television receiver shown in Fig. 4. In Fig. 0~ C C reference numerals 1A and IA' shows the images of the same bottle 1 as the inspected object and 2, 2' and 3, 3' are the windows or the inspection zones in the images IA and IAI of the bottle 1 respectively. Reference numeral 15 designates a location detection zone for the glass bottle 1, which is the inspected object, and 16 and 16' reference detection 0 0 J positions of the images IA and A'.

no Now, turning back to Fig. 3, the apparatus will be explained. The image signal of the inspected object or the glass bottle 1 as picked up by the video camera 5 is supplied to the synchronizing signal separator circuit 6, reference position detection section 7 and the inspection section 9 respectively. The synchronizing signal separator circuit 6 separates the vertical synchronizing signal V as well as the horizontal synchronizing signal H from the composite video signal from the video camera 5 and supplies the same to the reference position detection section 7 and the inspection zone posititon setting-up section 8. Needless to say, when the video camera 5 includes in itself the synchronizing signal separation function and the respective 8 '0 C r~---rtlanu~~ synchronizing signals are delivered separately to the image signal, this synchronizing signal separator circuit 6 may be eliminated. The respective synchronizing signals. H and V are used to determine the coordinate positions on the picture screen in the electronic circuit 14, which is the inspection apparatus of the present invention.

The synchronizing signals H and V are both supplied to a position detection zone setting circuit 7A of the reference position detection section 7, which then sets or determines its zone, for instance, position detection zone as shown in Fig. 5. This zone 15 is previously determined in accordance with the application manner of the apparatus so that this setting circuit 7A is/a stzd by, S for example, a counter, an IC memory or the like to store Sthe predetermined zone 15. In.the meantime, theX esignal from the video camera 5 is supplied to a position S detection circuit 7B of the reference position detection S eCtion 7 which then generates a detection signal based on o at image signal in the first field of the image signal and 0 on a part of the inspected ojbect or the glass bottle 1 within the position detection zone 15. This detection 00OO *signal is then supplied to the setting circuit 7A. For example, in the case of the embodiment shown in Fig. 5, the Souter surfaces of the left side walls of the images 1A and lA' of the glass bottle 1 are set as the reference detection positions 16 and 16', so that the position detection manner of the position detection circuit 7B is such one that the difference between the brightness and the darkness of the bottle 1 at the outer surface of the left side wall portion is detected by a comparator, and the side edge of the object 9 0 0 1 is detected or the like.

When the outer. surface of the lef t spide al, the inspected object 1 as transferred on the, belt d~v e r, Il in the direction A in Figt 4 is within the) position, Je~on zone 15r a reference signal generation circuit 7C req0S-Ves the output of the setting circuit 7A and gene~rateq, g m which becomes a reference signal, namely apstir Iref erence signal which is used to determine, th q pos Vti-=Ig jq the windows or inspection zones 2 and 3. This; positil, reference signal mn is supplied to the inspection lzoile position setting section 8. In this case, the, Eitting section B is provisled with an inspection zone pattern circuit 8A in which a given inspeotion zone pattern Is~ previously set and then preserved. The signal correondia to this given inspecton zone pattern in the circait MA In supplied to a pattern position setting circuit 8B of the setting section 8. Further, the position reference signal from the reference signal generation circuit 7C~ Q0 tbe reference position detection section 7 is supplied to the pattern position setting circuit 8B Of the setting section 8, wherery the inspection zone pattern of the inspection zone pattern circuit 8A is controlled to be positioned at a predetermined. position relative to the imagae IA by tile signal M.

4_ For instance, in Fig. S, refereiae numteral14 is a, time point when the reference detection position was 4eteta',-d.

Therefore, if it is aw~umed that this time point is tak 4a Us, a time point t2 which is apart from the tim~e point tl by, x (delay in timing) is. set as the Xett sirl" inspection zone ot window 3 and a tit 10'4 :i .1 a)' pp-a

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I1 said synchronizing signal; inspection zone position setting means storing an inspection zone of a predetermined shape and ~1 :1 t~ ii~i apart from the time point t2 by x' is set as the left side .dqe of the inspection, zone or window 2. Even through a reference detection position 16' of the image lA' at the left side of the picture screen 13A is detected, if the values x and x' are made constant, the relative positional relations of the inspection zones 2' and 3' to the image lA' of the bottle 1 will be always constant.

Further, in the above explanation, the left side surface of the image of the bottle 1 was caught as the reference position. However, there may be consider such a method that the left side surface and the right side surface of the image of the bottle 1 are detected as reference positions, respectively, a. the inspection zones or windows 2 and 3 are set therebetween. It is, however, free to select, depending upon the shape of the inspeicted object, one detection point or a plurality of detection points as S the reference position.

Then, under the state that the positioning of the inspection zone pattern was set up, a control signal generation circuit 8C of the setting section 8 receives the output of the setting circuit 8B, produces and supplies a control signal n to the inspection section S. In order that the inspection zone pattern circuit 8A stores the above-mentioned pattern, it is formed of, for example, an IC-ROM (inCegrated circuit read-only memory) or the like..

Further, the pattern circuit 8A receives such address signal to set the position of the pattern from the pattern position setting circuit 8B formed of, for example, a counter, a pulse generator or the like so as to sub-divide and restrict the horizontal position of the pattern. Simultaneously, i' 11

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is needless to say that this pattern position setting circuit 8B is controlled by the respective synchronizing signals H and V from the synchronizing signal separator circuit 6 in order to set the windows or the inspection zones 2 and 3 at the accurate positions within the picture screen.

The control signal n from the control signal generation circuit 8C is supplied to an inspection zone control circuit 9A of the inspection section 9 to thereby designates the inspection zones or windows 2 and 3. The inspection zone control circuit 9A to which the image signal from the video camera 5 is supplied may be, for example, a switching circuit which, only when there is the image signal within the inspection zones :hich are determined by the contrl signal n, supplies the image signal in the second field to a i judgement circuit 9B o: such a circuit which directly controls the operation of the judgement circuit 9B as construed by a computor or the like. The judgement circuit 9B carries out the inspection and the judgement of the image signal in the second field within the inspection zones 2 and 3 only and delivers the judgement result, namely a signal representing the existance or absence of defects or abnormalities ill the object 1 to the outside through a terminal Next, another application example of the present invention will be explained in reference with Figs. 6 and 7.

For example, when an object to be inspected such as the glass bottle 1 is desired to be inspected from various angles, it is sufficient that the glass bottle 1 is transferred on conveyer belt 11 while it is rotating. For 12

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example, as illustrated in Fig. 6, when the glass bottle 1 passes in front of the fixed camera (which is not shown in Fig. if the bottle 1 is transferred while rotated such t iat its image is moved from the right end towards the left end of the monitor picture screen 13A and the inspection is carried out at three positions, that is, the center position, the right end position and left end position on the monitor picture screen 13A, the same bottle 1 is inspected from thre different angles. In this case also, the respective inspection zones can be correctly set up by detecting the reference detection positions at the outer surface of the left side wall of the bottle 1, for example, time points P, 0 and Q so that the specific inspection purposes can be achieved. At this time, for example, although the operation of the judgement circuit 9B is stopped normally, a control signal for the initiation of ths operation is supplied through a terminal 9C, shown in Fig.

3, to the judgement circuit 9B so as to operate the judgement circuit 9B in synchronism with the moving speed of the belt conveyer 11 such that the judgemett circuit 9B delivers the judged result at three times at the appropriate positions of the bottle 1 on the monitor picture screen 13A.

Since the accurate satting of the inspection zones can be conducted automatically as. aforementioned, the timing of the control signal is not required so highly accurate. This control signal may be generated from, for example, a rotary encoder 9D shown in Fig. 3, which is in synchronism with the transfer speed of the conveyer 11.

Further, in order to transfer the bottle I on the straight line type belt conveyer 11 while being rotated, as

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f shown in Fig. 7, if the belt conveyer 11 is divided into, for example, four belt members 11A, 11B, 'lC and 11D and the transfer speeds of the respective belt members are changed sequentially by a little one another, it is possible to transfer the bottle whili it is being rotated. As to the methods to rotate the bottle while conveying the same, various means are known and the selection thereof may be freely made.

While the above explanation is made on the case where the light passed through the transparent glass bottle to be inspected is photosensed by the video camera and the image signal therefrom is processed, if the present invention is applied to inspect an opaque object such as a cylindrical can made of metal, the light from the light source is irradiated on the opaque object, the reflected light thereon S is photosensed by the video camera and the image signal therefrom is similarly processed as above. Then, the opaque object can be inspected.

Further, the explanation of the operation of the object inspection apparatus according to the present invention was made on the premise that the bottle 1 moves in the horizontal direction while the vertical direction remains Ssteady and the pattern of the inspection zone is set by only the horizontal control. However, when the bottle 1 is moved *at in the vertical direction, the pattern of the inspection zone is controlled in its vertical direction, similarly.

According to the present invention, when the inspection and the judgement are performed for only desired portions of the inspected object, by a simple circuit construction, the inspection zone corresponding to the desired portion of the 4I 14 inspected object can be automatically set if the object is within the visual or picking-up range of the video camera.

In the prior art, since the inspection zones are fixed at given positions within the visual area of the video camera, the inspcted object also had to be located at a predetermined position accurately upon inspecting the object. Also, in other prior art methods to automatically set the inspected zone, the entire image of the object had to be picked up and analyzed and then the procedure to set the inspection zone is carried out by a computor software, which required much processing time.

According to the present invention, a specific position of the object is noted, such specific position is detected by the image signal in the first field from the video camera, and making the position as a reference, the inspection zone is set and such set inspection zone is only inspected by the image signal in the second field.

Therefore, very high speed judgement can be conducted.

Further, according to the present invention, multiplc inspections can be made within one picture screen.

It will be apparent that many modifications and variations could be effected by one skilled in the art i without departing from the spirits or the scope of the novel 4 concepts of the present invention so that the spirits or scope of the invention should be determined by the appended claims only. 1

Claims (11)

1. An object inspection apparatus comprising: a light source for irradiating an object to be inspected; photosensing means for generating an image signal of said object including a synchronizing signal; and inspection means for receiving said image signal to determine whether or not said object has a defect; said inspection means having: reference position detecting means for Sgenerating a reference position signal based upon an an S,«a aimage signal in a first field of said image signal and 4 C S< said synchronizing signal; 15 inspection zone position setting means t storing an inspection zone of a predetermined shape and for generating a control signal based on said reference c( position signal and said synchronizing signal; inspection zone control means receiving the S 20 image signal from said photoensing means and the control signal from said inspection zone position setting means and for delivering an image signal in a second field of said image signal from said photosensing means within said inspection zone determined by said control signal; and judgement circuit means receiving the image y 16 1 signal from said inspection zone control means to judge whether or not said object has a defect.

2. An object inspection apparatus as claimed in claim 1, wherein said reference position detecting means have a position detecting circuit receiving the image signal from said photosensing means, a position detecting zone setting circuit receiving an output signal from said position detecting circuit and the synchronizing signal, and a reference signal generating circuit receiving an output signal from said position detecting zone setting circuit and generating the reference 0o 0 S 0 o position signal. ooao 0 0000 oo0

3. An object inspection apparatus as claimed in claim 0 o0 Q O 800 2, wherin said inspection zone position setting means S"go 15 have an inspection zone pattern circuit storing the 00 Q insrection zone of a predetermined shape, a pattern position setting circuit receiving a signal o" corresponding to the inspection zone from said inspection zone pattern circuit, the synchronizing signal and the reference position signal from said reference signal generating circuit, and a control L-b signal generating circuit receiving an output signal from said pattern position setting circuit and generating the control signal.

4. An object inspection apparatus according to claim 1 further comprising a synchronizing signal separator _b 1 i i L which separates the synchronizing signal from the image signal from said photosensing means.

An object inspection apparatus as claimed in cl;iim 1, wherein the synchronizing signal comprises horizontal and vertical synchronizing signals.

6. An object inspection apparatus according to claim 1 further comprising means fo ransporting a number of said objects in front of said photosensing means sequentially, in a rectilinear path.

7. An object inspection apparatus as claimed in claim 6, wherein said transpoiting means/aze a belt 0 0 0 on S9 co nveyo r. o0e0

8 An object inspection apparatus as claimed in claim sKo9 7, wherein said belt conveyor is formed of a plurality O Zo °o 15 of parallel belt members which are sequentially G tt different in moving speed whereby said object is transported while being 0 C S L7- 17a v l t~ ?i i -PILLILU UI. rotated in a visual field of said pick-up means.

9. An object inspection apparatus according to claim 8 further comprising means for supplying an operation control signal to said judging means whereby said judging means judge whether or not said object has a defect at a plurality of positions.

An object inspection apparatus as claimed in claim 9, wherein the operation control signal is generated in synchronism with a moving speed of said belt conveyer.

11. An object inspection apparatus as claimed in claim 3, wherein said pattern position setting circuit determines a relative position between the inspection zone and a reference point of said image based on the reference position signal. Q4u O, HAJIME INDUSTRIES LTD DATED THIS NINETEENTH DAY OF FEBRUARY 1987 4-4.l 18