JP2015094621A - Visual inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional visual inspection device using an optical cutting method, which accurately measures the thickness of inspection objects at high speed.SOLUTION: A visual inspection device comprises: a straight conveyance section 10 for conveying inspection objects K; and an inspection section for measuring the thickness of the inspection objects K and sorting the inspection objects on the basis of results of the measurement. The inspection section comprises: a slit light radiation section 23 for radiating slit light; an area sensor camera 22 for capturing an image of the slit light; first and second optical mechanisms 30, 35 for receiving reflected light of the slit light radiated to surfaces of the inspection objects K and a conveyance surface at the downstream side in a conveyance direction and guiding the light to the area sensor camera 22, and third and fourth optical mechanisms 40, 45 for receiving the reflected light at the upstream side and guiding the light to the area sensor camera 22; and an inspection section for measuring the thickness of each inspection object K and determining whether the thickness is within a proper range on the basis of the image captured by the area sensor camera 22.

Description

  The present invention relates to an apparatus for inspecting the appearance of pharmaceuticals (tablets, capsules, etc.), foods, machine parts, electronic parts, etc. (hereinafter referred to as “inspection object”).

  Conventionally, various apparatuses are known as apparatuses for inspecting the appearance of an inspection object, and the applicants of the present application also disclosed in Japanese Patent Application Laid-Open No. 2011-242319 a laser from the front-rear direction in the conveyance direction of the inspection object. An appearance inspection apparatus that irradiates slit light and images reflected light is proposed. Hereinafter, the appearance inspection apparatus will be described with reference to FIGS. 15 and 16. FIG. 15 is a front view showing a schematic configuration of a part of the appearance inspection apparatus, and FIG. 16 is a right side view.

This appearance inspection apparatus includes an image sensor 110, an area sensor camera 111 disposed above a conveyance path of a linear conveyance unit 100 including a conveyance belt 101, a slit light irradiator 112 that irradiates a strip-shaped slit light, Mirrors 113 and 114 for guiding the slit light L ′ irradiated from the slit light irradiator 112 directly below the area sensor camera 111 and irradiating the inspection target K ′ transported by the linear transport unit 100, and the inspection target K Reflected light L ₂ ′ of the slit light applied to “” is received from the downstream side in the conveyance direction (indicated by the arrow in FIG. 15) of the linear conveyance unit 100 and guided to the area sensor camera 111. 117, and receives from the upstream side of the reflected light _{L 3} ', Bei and mirrors 118 and 119 to put led similarly to the area sensor camera 111 To have.

The area sensor camera 111 includes an area sensor composed of elements arranged in double rows and double columns, and the two reflected lights L ₂ ′ and L ₃ ′ are in the raster direction within the area of the area sensor. The images are formed on the area sensor in a state of being aligned in a direction orthogonal to the horizontal direction (side by side state).

  Then, the area sensor camera 111 scans in a raster direction for a line having a preset width and outputs it as image data. Based on the output image data, the area sensor camera 111 measures the thickness of the inspection object K ′, Inspections such as surface shape are performed. In this appearance inspection apparatus, the region of interest of the area sensor camera is made as small as possible so that only the upper surface side of the inspection object K ′ is imaged, and the line width when scanning in the raster direction is narrowed. By shortening the time required for data output as much as possible, thickness measurement and appearance inspection can be performed at high speed.

JP 2011-242319 A

  By the way, when the inspection object K ′ is a medicine such as a tablet, the active ingredient depends on the presence or absence of scratches or chips on the surface of the inspection object K ′ and the thickness of the inspection object K ′. There is a change in the content, and the medicinal efficacy is not fully guaranteed. Therefore, it is required to accurately detect flaws and chips and measure the thickness of the inspection object.

  However, in the conventional appearance inspection apparatus, only the upper surface side of the inspection object K ′ is imaged, and the upper surface of the conveyance belt on which the inspection object K ′ is conveyed is not included in the region of interest. Therefore, when the height measurement data of the inspection object K ′ fluctuates for each measurement, whether the change is due to the thickness of the inspection object K ′ or the height position of the upper surface of the conveyor belt fluctuates. Therefore, there is a problem that the thickness of the inspection object K ′ cannot be accurately measured.

  Further, if the area of interest of the area sensor camera is enlarged and the upper surface of the inspection object K ′ and the upper surface of the conveyor belt are included in the region of interest, the thickness of the inspection object K ′ is accurately measured. In this case, the line width when outputting the image data must be widened, the time required for outputting the image data increases, and the speed when inspecting the inspection object K ′ decreases. To do.

  As described above, in the conventional appearance inspection apparatus, it is impossible to achieve both the accurate measurement of the thickness of the inspection object K ′ and the inspection of the inspection object K ′ at high speed.

  The present invention has been made in view of the above circumstances, and in a so-called three-dimensional appearance inspection apparatus using a light cutting method, the thickness of an inspection object can be measured quickly and accurately. The purpose is to provide.

The present invention for solving the above problems is as follows.
An appearance inspection apparatus comprising a transport mechanism that transports an inspection object along a predetermined transport surface, and an inspection mechanism that measures at least the thickness of the inspection object transported by the transport mechanism,
The inspection mechanism is disposed in the vicinity of the transport mechanism, and the strip-shaped slit light is perpendicular to the transport surface and the irradiation line is perpendicular to the transport direction of the inspection target. A slit light irradiation unit for irradiating the object surface and the conveying surface;
An area sensor camera that captures an image of the slit light applied to the inspection object surface and the conveying surface;
At least one first optical path having an optical path that receives the reflected light of the slit light irradiated on the surface of the inspection object from the downstream side or the upstream side along the conveyance direction of the inspection object and guides it to the area sensor camera. An optical mechanism;
At least one second optical mechanism having an optical path that receives the reflected light of the slit light irradiated on the transport surface from the same direction as the first optical mechanism and guides it to the area sensor camera;
An inspection unit that measures at least the thickness of the inspection object based on an image captured by the area sensor camera;
The optical paths of the first optical mechanism and the second optical mechanism are paths through which the reflected lights on the inspection object surface and the transport surface are imaged side by side along the raster direction in the imaging unit of the area sensor camera. This relates to the appearance inspection apparatus.

  According to this appearance inspection apparatus, the thickness of the inspection object conveyed by the conveyance mechanism is measured by the inspection mechanism.

  That is, first, the slit light is irradiated from the slit light irradiation unit to the surface of the inspection object to be transported and the transport surface. Then, the slit light applied to the surface of the inspection object is guided to the area sensor camera through the optical path of the first optical mechanism that receives the reflected light from the downstream side or the upstream side in the transport direction. . Similarly, the slit light applied to the transport surface is guided to the area sensor camera through the optical path of the second optical mechanism that receives the reflected light from the same direction as the first optical mechanism. It is burned. Then, the reflected light guided from the first optical mechanism and the second optical mechanism is imaged side by side along the raster direction within a preset region of the imaging unit in the area sensor camera.

  Next, the area sensor camera sequentially outputs data relating to the image formed in the setting area at predetermined shutter intervals. As the inspection object moves, the position of the slit light applied to the surface shifts, but the area sensor camera obtains the image data of the slit light for at least the entire surface of the inspection object. Output to.

  Then, the inspection unit measures the thickness of the inspection object based on the image data about the surface of the inspection object received from the area sensor camera and the image data about the transport surface. The inspection unit calculates the height position of the conveyance surface and the height position of the inspection object based on the images formed side by side in the imaging unit of the area sensor camera, and the calculated conveyance It is preferable that the thickness of the inspection object is measured based on the height position of the surface and the height position of the inspection object.

  Thus, according to the appearance inspection apparatus according to the present invention, each reflected light guided to the area sensor camera via each optical path of the first optical mechanism and the second optical mechanism is imaged by the area sensor camera. By forming the image side by side in the part, it is possible to form an image in which the surface of the object to be inspected and the transport surface are imaged in a predetermined setting area in the image forming part without expanding the region of interest. By outputting the data in the setting area, it is possible to output image data about the inspection target surface and image data about the transport surface.

  As described above, according to the present invention, an image in which the surface of the inspection object and the conveyance surface are captured is obtained, and image data about the inspection object and image data about the conveyance surface are output from the obtained image. Therefore, the thickness of the inspection object can be accurately measured, and further, the image of the inspection object surface and the conveyance surface can be obtained without expanding the region of interest. Thus, image data can be output without increasing the line width during scanning, and thickness measurement can be performed at high speed.

Each optical path of the first optical mechanism and the second optical mechanism is a path through which each reflected light on the surface of the inspection object and the transport surface forms an image side by side along the raster direction in the imaging unit of the area sensor camera. for,
A reflective surface disposed along an axial direction of a first axis that is orthogonal to the transport direction and parallel to the transport surface, and reflects the reflected light of the slit light applied to the surface of the inspection object. A first mirror that receives and reflects the light;
A reflective surface that is orthogonal to the transport direction and is disposed along the first axis, is inclined with respect to the reflective surface of the first mirror, and is disposed adjacent to the first mirror; A second mirror that receives and reflects the reflected light of the slit light applied to the surface to the reflecting surface;
A third mirror that has a reflecting surface disposed along an axial direction of a second axis orthogonal to the conveying surface, and receives and reflects light reflected by the first mirror and the second mirror;
A fourth mirror having a reflecting surface disposed along the transport direction, receiving and reflecting the light reflected by the third mirror, and guiding the reflected light to the area sensor camera;
In the first optical mechanism, an optical path of reflected light from the surface of the inspection object is defined by the first mirror, the third mirror, and the fourth mirror,
The second optical mechanism is preferably configured such that an optical path of reflected light from the transport surface is defined by the second mirror, the third mirror, and the fourth mirror.

  Even in this case, it is possible to obtain an image in which the surface of the inspection object and the conveyance surface are imaged without expanding the region of interest, and the image data on the inspection object and the conveyance surface can be obtained from the image with a predetermined line width. Therefore, the thickness of the inspection object can be measured quickly and accurately.

  Further, it is preferable that the second mirror is composed of a pair of two mirrors disposed on both sides of the first mirror along the first axis. If it does in this way, the reflected light reflected on the conveyance surface on both sides of the inspection object will be received and reflected, and this reflected light will be guided to the area sensor camera, and together with the reflected light on the surface of the inspection object in the imaging unit The image is formed side by side along the raster direction at the imaging unit. Thus, even when there is a deviation between the height positions of the conveyance surfaces on both sides of the inspection object, the image data about the inspection object surface and the image data about the conveyance surface on both sides of the inspection object Therefore, the thickness of the inspection object can be accurately measured.

  As described above, according to the present invention, the reflected light from the surface of the inspection object and the reflected light from the transport surface are imaged side by side without expanding the region of interest. The time required for the inspection can be made as short as possible, and the thickness of the inspection object can also be accurately measured.

It is the front view which showed the external appearance inspection apparatus which concerns on one Embodiment of this invention. It is the block diagram which showed the structure of the test | inspection part which concerns on one Embodiment. It is sectional drawing of the arrow AA direction in FIG. It is the front view which showed the image imaging part which concerns on one Embodiment. It is a right view of the image pick-up part shown in FIG. It is a top view of the image pick-up part shown in FIG. It is explanatory drawing which showed the aspect with which slit light is irradiated in one Embodiment. It is explanatory drawing which shows the state which looked at the slit light shown in FIG. 7 from the front-back direction along the conveyance direction of a test target object. It is explanatory drawing for demonstrating the aspect which adjusts the angle of each mirror of the 1st optical mechanism which concerns on one Embodiment, a 2nd optical mechanism, a 3rd optical mechanism, and a 4th optical mechanism. It is explanatory drawing for demonstrating the aspect which adjusts the angle of each mirror of the 1st optical mechanism which concerns on one Embodiment, a 2nd optical mechanism, a 3rd optical mechanism, and a 4th optical mechanism. It is explanatory drawing for demonstrating the aspect which adjusts the angle of each mirror of the 1st optical mechanism which concerns on one Embodiment, a 2nd optical mechanism, a 3rd optical mechanism, and a 4th optical mechanism. It is explanatory drawing which showed the image imaged by the area sensor camera which concerns on one Embodiment. It is explanatory drawing which showed the reference | standard height position of the reference | standard thing surface and a conveyance surface. It is explanatory drawing in order to demonstrate the calculation method of the thickness of a test target object. It is the front view which showed the conventional image pick-up device. It is the right view which showed the conventional image pick-up device.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the appearance inspection apparatus 1 of the present example is conveyed by a supply unit 3 that supplies the inspection object K in an aligned manner, a linear conveyance unit 10 that linearly conveys the supplied inspection object K, and the conveyance unit 10. And an inspection mechanism 20 that measures the thickness of the inspection object K and selects based on the measurement result.

  Examples of the inspection object K in this example include pharmaceuticals (tablets, capsules, etc.), foods, machine parts, electronic parts, and the like.

  Hereinafter, the details of each of the above parts will be described.

[Supply section]
The supply unit 3 includes a hopper 4 into which a large number of inspection objects K are charged, a vibration feeder 5 that imparts vibration to the inspection object K discharged from the lower end portion of the hopper 4, and advances the vibration feeder 5. Chute 6 for sliding down inspection object K discharged from the end of conveyance, horizontal rotation, alignment table 7 for discharging inspection object K supplied from chute 6 in a line and disk rotating in a vertical plane A rotating conveyance object 8 having a disk-shaped member and adsorbing and conveying the inspection object K discharged from the alignment table 7 to the outer peripheral surface of the disk-shaped member, and a large number of inspection objects K are arranged in a row. Align and sequentially transfer to the linearly conveyed product 10.

[Linear conveyance unit]
3 is a partial cross-sectional view in the direction of the arrow AA in FIG. 1. As shown in FIG. 3, the linear transport unit 10 includes side plates 11 disposed so as to face each other at a predetermined interval. 12 and a pair of endless conveying belts 13 and 14 that are guided by guide grooves formed on the upper surfaces of the side plates 11 and 12 and run along the guide grooves.

  The space sandwiched between the side plates 11 and 12 is closed by the side plates 11 and 12 and other members (not shown) so that the upper part is released, and is maintained at a negative pressure by a vacuum pump (not shown).

  Thus, when the space is maintained at a negative pressure, a suction force due to a negative pressure is generated between the conveyor belts 13 and 14 traveling along the guide groove, and the inspection object K is transferred to the conveyor belts 13 and 14. When placed on the belt, the suction force attracts and sucks onto the conveyor belts 13 and 14, and is conveyed in the same traveling direction as the conveyor belts 13 and 14 travel.

[Inspection mechanism]
The inspection mechanism 20 includes an image capturing unit 21, an inspection unit 50, and a selection unit 60.

As shown in FIG. 4, the image pickup unit 21 includes an area sensor camera 22 disposed above the conveyance path of the linear conveyance unit 10, a slit light irradiator 23 that irradiates a strip-shaped slit light L ₁ , and this The mirrors 24 and 25 that irradiate the slit light L ₁ emitted from the slit light irradiation 23 onto the conveyance path of the linear conveyance unit 10, and the reflected light L _2s that the slit light L ₁ is reflected from the surface of the inspection object K are linear the conveying direction of the conveying section 10 by receiving the (arrow) downstream, a first optical mechanism 30 to put led to the area sensor camera 22, (the plane formed by the conveyor belt 13, 14) slit beam L ₁ is conveying surface The second optical mechanism 35 that receives the reflected light L _2b reflected at the downstream side of the linear transport unit 10 and guides it to the area sensor camera 22 and the reflected light L _3s reflected at the surface of the inspection object K The third optical mechanism 40 that receives light from the upstream side in the transport direction and guides it to the area sensor camera, and receives the reflected light L _3b reflected by the transport surface from the upstream side and similarly guides it to the area sensor camera. 4 optical mechanism 45.

The slit light irradiator 23 and the mirrors 24 and 25 irradiate the slit light L _{1 such} that the irradiation line is orthogonal to the transport direction (arrow direction) of the inspection object K transported by the linear transport unit 10. Irradiate vertically downward. The state according slit beam L ₁ is irradiated to the surface and the transport path surface of the inspection object K is shown in Fig.

  Further, as shown in FIGS. 4 to 6 and 9, the first optical mechanism 30 and the third optical mechanism 40 include first mirrors 31 and 41, respectively, and a second optical mechanism 35 and a fourth optical mechanism 45. Are provided with second mirrors 36 and 46, respectively, and the first optical mechanism 30 and the second optical mechanism 35, and the third optical mechanism 40 and the fourth optical mechanism 45 are third mirrors as respective shared mirrors. 37 and 47, and these four optical mechanisms 30, 35, 40, and 45 include a fourth mirror 48 as a shared mirror.

The first mirror 31 has a reflection surface 31a disposed along the axial direction of a first axis (virtual axis) orthogonal to the conveyance direction of the linear conveyance unit 10 and parallel to the conveyance surface. The reflected light L _2s of the slit light L ₁ irradiated on the surface of the inspection object K is received and reflected from the downstream side to the reflecting surface 31a.

Similarly, the first mirror 41, along said axial direction of the first axis of the virtual has disposed reflective surface 41a, the reflection of irradiated slit light L ₁ on the surface of the inspection object K Light _L3s is received and reflected from the upstream side to the reflecting surface 41a.

  These first mirrors 31 and 41 are respectively provided with rotation axes 31b and 41b along virtual first axes, and by rotating the rotation axes 31b and 41b around the axes, the reflection surfaces 31a and 41a with respect to the horizontal plane are rotated. The angle can be adjusted, and the rotary shafts 31b and 41b function as an angle adjusting unit.

The second mirror 36 is composed of a pair of two mirrors disposed on both sides of the first mirror 31 along the axial direction of the first axis so as to be rotatable with respect to the rotation shaft 31b. has a reflective surface 36a disposed along the axial direction of the first axis, the reflected light L _2b of the irradiated slit beam L ₁ on the conveying surface, and receives from the downstream side to the reflecting surface 36a It is configured to reflect.

The second mirror 46 also includes a pair of two mirrors disposed on both sides of the first mirror 41 along the axial direction of the first axis so as to be rotatable with respect to the rotation shaft 41b. has a reflective surface 46a disposed along the axial direction of the first axis of the imaginary, the reflected light L _3b of the slit light L ₁ irradiated to the conveying surface, on the reflection surface 46a from the upstream side It is configured to receive and reflect light.

  The third mirror 37, which is a shared mirror of the first optical mechanism 30 and the second optical mechanism 35, is a reflecting surface disposed along the axial direction of the second axis (virtual axis) orthogonal to the transport surface. 37a, and is arranged so that the light reflected by the first mirror 31 and the second mirror 36 is received by the reflecting surface 37a and irradiated toward the fourth mirror 48.

  Similarly, a third mirror 47, which is a shared mirror of the third optical mechanism 40 and the fourth optical mechanism 45, has a reflective surface 47a disposed along the axial direction of the second axis, and the first mirror The light reflected by the mirror 41 and the second mirror 46 is received by the reflecting surface 47 a and is radiated toward the fourth mirror 48.

These third mirrors 37 and 47 are respectively provided with rotation axes 37b and 47b along the virtual second axis, and the rotation surfaces 37b and 47b are rotated around the axis, whereby the reflection surface 37a with respect to the vertical plane is obtained. , 47a can be adjusted, and the rotation shafts 37b, 47b function as an angle adjusting section. As shown in FIG. 9, on the reflection surface of the third mirror 37 in this example, a reflection part 37a ₁ (a part surrounded by a one-dot chain line) that receives and reflects the reflected light from the first mirror 31 and a second part A reflection portion 37a ₂ (a portion surrounded by a dotted line) that receives and reflects the reflected light from the mirror 36 is set, and similarly, the reflected light from the first mirror 41 is formed on the reflective surface of the third mirror 47. And a reflection portion 47a ₁ (a portion surrounded by an alternate long and short dash line) that receives and reflects the light and a reflection portion 47a ₂ (a portion surrounded by a dotted line) that receives and reflects the reflected light from the second mirror 46 are set. Has been. Each of the third mirrors 37 and 47 is composed of three mirrors arranged side by side along the axial direction of the first axis, and the reflecting surface of each mirror is the reflecting portions 37a ₁ and 37a. ₂ , 47 a ₁ , 47 a ₂ .

The fourth mirror 48, which is a shared mirror of the four optical mechanisms, has a reflection surface 48a disposed along the transport direction, and reflects the light reflected by the third mirrors 37 and 47, respectively. Light is received side by side at 48 a and the reflected light in the side by side state is guided to the area sensor camera 22. As shown in FIG. 9, the reflection surface of the fourth mirror 48 receives a reflection light from the surface of the inspection object K and reflects it, and a reflection portion 48 a ₁ (a portion surrounded by a one-dot chain line) and a conveyance surface. Reflecting portions 48a ₂ (portions surrounded by dotted lines) that receive and reflect the reflected light, that is, six reflecting portions are set. The fourth mirror 48 is composed of six mirrors arranged side by side along the transport direction, and the reflective surface thereof is the reflective portion 48a ₁ and the reflective portion in order from the downstream mirror in the transport direction. 48a _2, the reflective portion 48a _1, the reflecting portion 48a _1, the reflecting portion 48a _2, may be a reflection part 48a _1.

The area sensor camera 22 includes an area sensor camera composed of elements arranged in double rows and double columns, and receives reflected light L ₂ (reflected light L from the surface of the inspection object K) received on the downstream side. _2s and reflected light L _2b from the transport surface) and reflected light L ₃ received upstream (reflected light L _3s from the surface of the inspection object K and reflected light L _3b from the transport surface) are respectively the first optical. Through the optical paths of the mechanism 30, the second optical mechanism 35, the third optical mechanism 40, and the fourth optical mechanism 45, they are guided into the area sensor camera 22 in a side-by-side state, and imaged side by side on the area sensor. Is done.

Incidentally, the area sensor, _{X n} columns in the raster direction, has an element of _{Y m} rows in a direction perpendicular thereto, the reflected light _{L 2s, L 2b, L 3s} , L 3b _is, Y h to Y _Images are arranged side by side in the raster direction within a range of _l rows (hereinafter referred to as “lines”).

8, the inspection object K which slit light L ₁ is irradiated, it shows a view with the naked eye from each diagonally above the downstream side and the upstream side. As shown in the figure, the reflected lights L _2s and L _3s from the surface of the inspection object K are shifted upward from the reflected lights L _2b and L _3b from the transport surface. It is intended viewing direction is due to intersection with the irradiation direction of the slit beam L _1, is a so-called light cutting method, a slit beam irradiated on the inspection object K surfaces the inspection object K According to the height of the surface, it can be seen shifted upward from the slit light applied to the conveying surface.

  By the way, the shift amount of the slit light irradiated on the surface of the inspection object K with respect to the slit light irradiated on the transport surface differs depending on the viewing angle (elevation angle).

Accordingly, the first mirror 31 and 41, whose the elevation is spaced equidistantly respectively in the longitudinal direction from the irradiation position to the transport path of the slit beam L ₁ so as to have the same angle, and the upper height position It arrange | positions so that it may become the same height position, and it is made for the height information contained in this to be the same between the images of the front-back direction about the surface of the test target K imaged by the area sensor camera 22. Is preferred.

Further, in the appearance inspection apparatus 1 of this example, as shown in FIG. 4, the reflection surface of the second mirror 36 in the second optical mechanism 35 with respect to the reflection surface 31 a of the first mirror 31 in the first optical mechanism 30. 36a is inclined, and the reflection surface 46a of the second mirror 46 in the fourth optical mechanism 45 is inclined with respect to the reflection surface 41a of the first mirror 41 in the third optical mechanism 40, so that the surface from the surface of the inspection object K is inclined. The reflected light L _2s and the reflected light L _3s , and the reflected light L _2b and the reflected light L _3b from the transport surface are each imaged in a region of a predetermined bandwidth on the area sensor. Incidentally, for the second mirror 36 and 46, spaced equidistantly on each front-rear direction from the irradiation position of the conveying path of the slit beam L _1, and arranged so that the height position of the upper are the same height It is preferable that the height information included in the images in the front-rear direction of the conveyance surface imaged by the area sensor camera 22 is the same.

Therefore, in this example, before the thickness measurement, the four reflected lights L _2s , L _2b , L _3s , and L _3b are imaged on the area sensor by the method shown in FIGS. The position is adjusted.

  That is, as shown in FIG. 9, first, a cylindrical test piece P is placed on the transport path so that its axis is along the transport direction, and then slit light is irradiated from the slit light irradiator 23. .

Next, in this state, as shown in FIG. 10, by rotating either one or both of the rotation shaft 31b of the first mirror 31 and the rotation shaft 41b of the first mirror 41, each reflection surface 31a with respect to the horizontal plane. , 41a are adjusted, and after being reflected by the third mirrors 37, 47, the received light height positions of the reflected light _L2s , _L3s received by the fourth mirror 48 are the same height position between each other. And adjusting one or both of the second mirror 36 and the second mirror 46 about the rotation shaft 31b or 41b to adjust the angles of the reflecting surfaces 36a and 46a. The light receiving height positions of the reflected lights L _2b and L _3b received by the four mirrors 48 are set to the same height position. At this time, the four reflected lights L _2s , L _3s , L _2b , and L _3b are adjusted so as to form an image between the Y _h to Y ₁ lines of the area sensor.

Next, as shown in FIG. 11, the angle of each reflecting surface 37a, 47a with respect to the vertical surface is rotated by rotating either one or both of the rotating shaft 37b of the third mirror 37 and the rotating shaft 47b of the third mirror 47. To adjust the light receiving position of the reflected light L _2s , L _{3s in} the horizontal direction and the light receiving position of the reflected light L _2b , L _{3b in} the horizontal direction at the fourth mirror 48, and these four reflected lights move in the X direction. The image is formed on the area sensor without protruding.

As described above, in the state in which the positions where the reflected lights L _2s , L _2b , L _3s , and L _3b are imaged are adjusted, the image of the surface of the inspection object K and the conveyance surface captured by the area sensor camera 22 is displayed. An example is shown in FIG. As shown in the figure, the reflected light L _2s guided by the optical path of the first optical mechanism 30, the reflected light L _{2 b} guided by the optical path of the second optical mechanism 35, and the optical path of the third optical mechanism 40. The reflected light L _3s guided by the optical path and the reflected light L _3b guided by the optical path of the fourth optical mechanism 45 are imaged on an area sensor (a region indicated by a one-dot chain line). Note that the image formed by the reflected lights L _2s and L _2b and the image formed by the reflected lights L _3s and L _3b are formed in a state where the left and right are reversed from each other.

Then, the area sensor camera 22 sequentially scans the element data in the Y _{h to} Y _l lines in the raster direction at a predetermined shutter speed interval, and reads the luminance data detected by each element, as shown in FIG. As shown, position data (X _i , Y _j ) consisting of the pixel position (X _i ) in the X direction and the pixel position (Y _j ) having the maximum luminance in the column for the surface of the inspection object K and the transport surface. ) As image data to the inspection unit 50.

Incidentally, the area sensor camera 22, at least, the image data while the laser beam L ₁ on the surface of the inspection object K is irradiated is transmitted to the inspection unit 50 as a frame image obtained for each shutter.

  As shown in FIG. 2, the inspection unit 50 includes an image storage unit 51, a reference height position determination unit 52, a thickness calculation unit 53, a thickness determination processing unit 54, and a selection control unit 55.

  The image storage unit 51 stores the image data (frame image) received from the image capturing unit 21.

The reference height position determination unit 52 determines the reference height position T _s based on the reference object S whose thickness is known in advance before measuring the thickness of the inspection object K, and the thickness. A reference height position T _bs of the conveyance surface which is a height position where the length is 0 is determined.

A specific method for determining the reference height positions T _s and T _bs is as follows. First, in the state where the reference object S is sucked and sucked onto the conveyor belts 13 and 14, the image pickup unit 21 performs the first optical operation. Reflected light L _2s ′, L _3s ′ about the surface of the reference object S guided by the optical path of the mechanism 30 and the third optical mechanism 40, and a transport surface guided by the optical path of the second optical mechanism 35 and the fourth optical mechanism 45 After obtaining an image in which the reflected lights L _2b and L _3b are imaged on the area sensor, the element data in the Y _{h to} Y _l lines are sequentially scanned in the raster direction and detected by each element. Luminance data is read out, and position data composed of the pixel position in the X direction and the pixel position in the Y direction having the maximum luminance in the column for the surface of the reference object S and the conveyance surface is generated as image data, and an image storage unit 5 To send to.

Next, the reference height position determination unit 52 reads the image data on the surface of the reference object S and the conveyance surface stored in the image storage unit 51, and determines the reference height positions T _s and T _bs that are pixel positions in the Y direction. Determine (see FIG. 13).

  The thickness calculation unit 53 reads the frame image stored in the image storage unit 51, performs the following processing, and calculates the thickness of the inspection object K.

Specifically, first, frame image data is sequentially read out, and each frame image is scanned in a raster direction to detect the position data (X _i , Y _j ) on the surface of the inspection object K and the conveyance surface. , based on the detected position data, the height position T is a pixel position in the Y direction to determine the T _b.

Then, to calculate the variation Δt of height T of the inspection object K surface from the reference height position T _s that is determined by the reference height position determination unit 52, from the reference height position T _bs The fluctuation amount Δt _b of the height position T _b of the transport surface is calculated. Incidentally, the calculated variation Delta] t, Delta] t _b is equal to the number of elements of the area sensor camera.

Thereafter, the calculated two variation Delta] t, the Delta] t _b respectively, and calculates the actual variation amount multiplied by a coefficient X determined by the optical magnification and elevation. Then, the plus the actual variation amount calculated from the thickness variation Delta] t of the reference object S, by adding the actual variation amount of the conveying surface calculated from the variation amount Delta] t _b, the thickness of the test object K Calculate (see FIG. 14). Note that in FIG. 14 shows a state in which fluctuations below the height position T _b is the reference height position T _bs of conveying surface, in this case, as described above, the reference object S thickness The actual thickness of the inspection object K is calculated by adding the actual fluctuation amount of the transport surface to the above. In contrast, in a state where the variation above the height T _b is the reference height position T _bs of the conveying surface, by subtracting the actual variation amount of the conveying surface from the thickness of the reference object S, inspection The actual thickness of the object K is calculated.

  The thickness determination processing unit 54 determines whether or not the thickness of the inspection object K calculated by the thickness calculation unit 53 is within an appropriate range.

  When the selection control unit 55 receives the determination result from the thickness determination processing unit 54 and receives the determination result outside the appropriate range, the inspection object K determined to be out of the appropriate range reaches the selection unit 60. The sorting signal is transmitted to the sorting unit 60 at the timing to be performed.

  The sorting unit 60 is provided at the transport end of the linear transport unit 10 and includes a sorting collection mechanism, a non-defective product collection chamber, and a defective product collection chamber (not shown), and when a sorting signal is received from the sorting control unit 55, By driving the sorting and collecting mechanism, the inspection object K transported to the end of transport of the linear transport unit 10 is recovered in the non-defective product recovery chamber, and the thickness is out of the proper range. Collect some items in the defective product collection room.

According to the appearance inspection apparatus 1 of this embodiment having the above configuration, first, while the inspection object K is conveyed by the straight conveying section 10, the slit light L ₁ of the image is an image captured to be irradiated on the surface The image is captured by the unit 21, and the captured image data is transmitted from the image capturing unit 21 to the inspection unit 50.

  Next, based on the captured image, the inspection unit 50 automatically inspects whether or not the thickness of the inspection object K is within an appropriate range. And defective products are automatically sorted out.

Then, in the appearance inspection apparatus 1 of this embodiment, when an image of the slit beam L _1, the third optical system in the conveying direction of the downstream side first optical mechanism 30 and the second optical mechanism 35, and the upstream side 40 In the area sensor of the area sensor camera 22, the reflected lights L _2s , L _2b , L _3s , and L _3b guided through the optical paths of the fourth optical mechanism 45 are connected side by side in a narrower region than in the conventional case. Can be imaged. Therefore, conventionally, it has been necessary to widen the region of interest in order to image the surface of the inspection object K and the transport surface with a single optical mechanism. However, in the appearance inspection apparatus 1 of this example, Without expanding the region of interest, it is possible to obtain an image obtained by imaging the surface of the inspection object K and the conveyance surface, and simultaneously output image data about the surface of the inspection object K and image data about the conveyance surface. The thickness of the inspection object can be measured at a higher speed than in the past.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to these at all.

  For example, in the above example, the thickness of the inspection object K is also measured when the conveyance surfaces of the conveyance belts 13 and 14 on both sides of the inspection object K are imaged and the height positions are different between the conveyance belts 13 and 14. In order to be able to accurately measure the height, the second mirrors 36 and 46 are configured by a pair of mirrors disposed on both sides of the first mirrors 31 and 41. However, the present invention is not limited to such a mode, and a mode including a single mirror disposed only on one side of the first mirrors 31 and 41 may be employed.

  In the above example, the reflected light of the slit light applied to the surface of the inspection object K and the transport surface is received from the downstream side and the upstream side in the transport direction, but is received only from the downstream side or the upstream side. You may make it do.

  Further, in the above example, the image of the surface of the inspection object K and the conveyance surface formed in the area sensor is sequentially scanned in the raster direction, and image data about the surface of the inspection object K and the conveyance surface is output. However, the present invention is not limited to this. For example, in order from the left toward the paper surface of FIG. 12, the scanning is sequentially performed in the raster direction for each predetermined region (the region surrounded by the dotted line in FIG. 12). You may make it output the image data about the surface of a thing K and a conveyance surface.

  Further, the inspection mechanism 50 in the appearance inspection apparatus 1 of the present example may inspect the surface shape of the inspection object K, for example, in addition to measuring the thickness of the inspection object K.

In this case, the area sensor camera 22 scans the data of the elements in the Y _{h to} Y _l lines, reads the luminance data detected by each element, and reads the X data about the surface of the inspection object K and the transport surface. An inspection unit using, as image data, data associating position data (X _i , Y _j ) composed of a pixel position (X _i ) in the direction and a pixel position (Y _j ) having the maximum luminance within the column and the luminance data 50 is configured to be transmitted.

  The inspection unit 50 further includes a luminance data conversion processing unit, an image composition processing unit, a shape feature extraction processing unit, and a shape determination processing unit.

The luminance data conversion processing unit reads the frame image stored in the image storage unit 51, and has 256 gradations in which position data derived from the height component of the surface of the inspection object K is set according to the height component. The luminance image data including the pixel position (X _i ) and the luminance data is generated for each of the images picked up from the two directions on the upstream side and the downstream side in the transport direction.

  Further, the image composition processing unit synthesizes the luminance image data in the two directions generated by the luminance data conversion processing unit, and performs processing to form one luminance image data. In the synthesis of luminance image data, if data is missing between the two luminance image data, the data that exists is applied, and if there is data mutually, the average value is applied, A composite image in which the entire surface of the inspection object K is accurately represented can be obtained.

  The shape feature extraction processing unit smoothes the synthesized image generated by the image synthesis processing unit with a so-called smoothing filter, and obtains a difference between the obtained smoothed image data and the synthesized image data. Generate image data.

  Based on the feature image related to the surface shape generated by the shape feature extraction processing unit, the shape determination processing unit compares this with the data related to the appropriate surface shape, and whether or not the stamp is appropriate The quality is determined, and the determination result is transmitted to the sorting control unit 55.

  In addition, when the selection control unit 55 receives the determination result of the defect from the shape determination processing unit, the selection signal related to the surface shape is sent to the selection unit at the timing when the inspection object K determined to be defective reaches the selection unit 60. Send.

  According to the appearance inspection apparatus configured as described above, it is possible to determine whether or not the thickness of the inspection object K is appropriate, and also determine whether or not the surface shape is appropriate, and it is determined that the thickness and the surface shape are not appropriate. The inspection object K can be collected.

DESCRIPTION OF SYMBOLS 1 Appearance inspection apparatus 10 Linear conveyance part 20 Thickness inspection part 21 Image pick-up part 22 Area sensor camera 23 Slit light irradiator 30 1st optical mechanism 31 1st mirror 35 2nd optical mechanism 36 2nd mirror 37 3rd mirror 40 1st 3 optical mechanism 41 1st mirror 45 4th optical mechanism 46 2nd mirror 47 3rd mirror 48 4th mirror 50 Inspection part 51 Image storage part 52 Reference height position determination part 53 Thickness calculation part 54 Thickness judgment processing part 55 Sorting control unit 60 Sorting unit

Claims (4)

An appearance inspection apparatus comprising a transport mechanism that transports an inspection object along a predetermined transport surface, and an inspection mechanism that measures at least the thickness of the inspection object transported by the transport mechanism,
The inspection mechanism is disposed in the vicinity of the transport mechanism, and the strip-shaped slit light is perpendicular to the transport surface and the irradiation line is perpendicular to the transport direction of the inspection target. A slit light irradiation unit for irradiating the object surface and the conveying surface;
An area sensor camera that captures an image of the slit light applied to the inspection object surface and the conveying surface;
At least one first optical path having an optical path that receives the reflected light of the slit light irradiated on the surface of the inspection object from the downstream side or the upstream side along the conveyance direction of the inspection object and guides it to the area sensor camera. An optical mechanism;
At least one second optical mechanism having an optical path that receives the reflected light of the slit light irradiated on the transport surface from the same direction as the first optical mechanism and guides it to the area sensor camera;
Based on an image picked up by the area sensor camera, comprising at least an inspection unit for measuring the thickness of the inspection object,
The optical paths of the first optical mechanism and the second optical mechanism are paths through which the reflected lights on the inspection object surface and the transport surface are imaged side by side along the raster direction in the imaging unit of the area sensor camera. An appearance inspection apparatus characterized by The inspection unit
The height position of the conveyance surface and the height position of the inspection object are calculated based on the image formed side by side in the imaging unit of the area sensor camera, and the calculated height position of the conveyance surface and the inspection are calculated. The appearance inspection apparatus according to claim 1, wherein the appearance inspection apparatus is configured to measure a thickness of the inspection object based on a height position of the object. A reflective surface disposed along an axial direction of a first axis that is orthogonal to the transport direction and parallel to the transport surface, and reflects the reflected light of the slit light applied to the surface of the inspection object. A first mirror that receives and reflects the light;
A reflective surface that is orthogonal to the transport direction and is disposed along the first axis, is inclined with respect to the reflective surface of the first mirror, and is disposed adjacent to the first mirror; A second mirror that receives and reflects the reflected light of the slit light applied to the surface to the reflecting surface;
A third mirror that has a reflecting surface disposed along an axial direction of a second axis orthogonal to the conveying surface, and receives and reflects light reflected by the first mirror and the second mirror;
A fourth mirror having a reflecting surface disposed along the transport direction, receiving and reflecting the light reflected by the third mirror, and guiding the reflected light to the area sensor camera;
In the first optical mechanism, an optical path of reflected light from the surface of the inspection object is defined by the first mirror, the third mirror, and the fourth mirror,
3. The appearance inspection apparatus according to claim 1, wherein in the second optical mechanism, an optical path of reflected light from a conveyance surface is defined by the second mirror, the third mirror, and the fourth mirror. The visual inspection apparatus according to claim 3, wherein the second mirror includes a pair of two mirrors disposed on both sides of the first mirror along the first axis.

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