JP2007071775A - Visual examination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual examination device capable of inspecting the appearance of a workpiece by a simple mechanism in a process for feeding the workpiece housed in the workpiece housing part of a turntable. <P>SOLUTION: The visual examination device is constituted of the turntable 31, which has a plurality of the workpiece housing part 31a for housing workpieces one by one to feed them, provided to its outer peripheral part, a sending-out means for sucking and holding the workpieces (w) housed in the workpiece housing parts 31a to send out them to the external space of the turntable 31 and an inspection means for inspecting the appearance of each of the workpieces (w) sent out of the turntable 31. After the workpiece housing parts 31a of the turntable 31 are positioned at predetermined positions, the workpieces (w) of the workpiece housing parts 31a are sent out by suction nozzles 28 being sending means and the workpieces (w) in the external space of the turntable 31 are inspected by an imaging means 37 being an inspection means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an appearance inspection apparatus that inspects the appearance of a workpiece such as a chip-shaped electronic component.

  For example, as an appearance inspection apparatus 50 for inspecting the appearance of a hexahedron such as a chip-shaped electronic component, the one shown in FIG. 6 is conventionally known. FIG. 6 is a perspective view of the appearance inspection apparatus 50, and a chip-shaped electronic component (hereinafter referred to as a workpiece) having a hexahedron is supplied from the linear feeder 51 to the horizontal turntable 52. A plurality of workpiece storage portions 52a each having a concave portion in which a workpiece is stored are provided at the peripheral edge of the horizontal turntable 52, and the workpieces are separately stored in the workpiece storage portions 52a one by one. Then, in the process in which the workpiece is conveyed along with the rotation of the horizontal turntable 52, the side surface of the workpiece in the workpiece storage portion 52a is imaged by the imaging means 54a provided outside the peripheral edge of the horizontal turntable 52. Further, the upper and lower surfaces of the workpiece in the workpiece storage portion 52a are imaged by the imaging means 54b and 54c provided in the vertical direction of the horizontal turntable 52, respectively.

  The imaging data from the imaging means 54a, 54b, 54c is sent to an image processing apparatus (not shown), subjected to image processing, and quality is determined. The workpieces determined as defective are discharged from the workpiece receiving box 55, and a plurality of normal workpieces are provided on the peripheral edge of the orthogonal turntable 53 through the workpiece transfer position 57 from the workpiece storage portion 52a of the horizontal turntable 52. It is transferred to the storage part 53a. The workpiece transferred to the orthogonal turntable 53 side is imaged on the side surface of the workpiece by the imaging means 54d provided outside the peripheral edge of the orthogonal turntable 53, and further provided on the left and right sides of the orthogonal turntable 53, respectively. The left and right surfaces of the workpiece in the workpiece storage unit 53a are imaged by the imaging means 54e and 54f.

  The imaging data from the imaging means 54d, 54e, 54f is sent to an image processing device (not shown), subjected to image processing, and quality is determined. The work determined to be defective is discharged from the work receiving box 56, and a normal work is delivered to the next process through a work take-out section (not shown).

  In the appearance inspection apparatus 50 configured as described above, it is possible to inspect up to six faces of a workpiece. However, when an appearance inspection of four or more faces is performed, the horizontal turntable 52 and the vertical turntable 53 that convey a workpiece are referred to as two. Two turntables are required, and it is necessary to control the two turntables 52 and 53 to rotate intermittently in synchronization. Further, the mechanism such as the work holding means or the transfer means becomes precise and complicated, which increases the cost.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to inspect the appearance of at most five surfaces of the workpiece, particularly in the process of storing the workpiece in the workpiece storage portion of the turntable and transporting the workpiece. An object of the present invention is to provide an appearance inspection apparatus that can be inspected by a simple mechanism and can reduce costs when one surface may be a silhouette inspection.

  In order to achieve the above-mentioned object, the present invention sucks and holds a turntable having a plurality of work storage portions for storing and transporting workpieces one by one on the outer peripheral portion, and the work stored in the work storage portion. And an inspection means for inspecting the appearance of the work sent from the turntable, and the work storage unit is positioned at a predetermined position by rotating the turntable. Then, the work in the work storage unit is sent out to the external space of the turntable by the sending means, and the appearance of the work is inspected by the inspection means.

  The work stored and transported in the work storage part of the turntable is sucked and held by the sending means and sent to the external space of the turntable, so that the wall of the work storage part becomes a barrier and the inspection cannot be performed. It is characterized in that the appearance of the work surface can be inspected by the inspection means.

  According to the present invention, it is possible to inspect the surface of a workpiece that could not be inspected because the wall surface of the workpiece storage portion becomes a barrier by a simple mechanism without using a plurality of turntables, thereby reducing costs. There is an effect that can be.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show the first embodiment, FIG. 1A is a front view of a part of the appearance inspection apparatus, and FIG. 1B is a view taken along the line A-A in FIG. FIG. 2 is a perspective view showing a workpiece storing recess, FIG. 3 is an enlarged view of a main part of FIG. 1, (a) is a plan view, (b) is a side view, (c) is a front view, and (d) is an optical path. FIG. 4 is an explanatory view of the illumination means.

  1 (a) and 1 (b), a slide base holder 3 is fixedly provided on the surface of the base plate 2 of the appearance inspection apparatus 1 (hereinafter, the front side is the upper side and the back side is the lower side). The slide base holder 3 is provided with a slide base 4 that is pivotable about a pivot shaft 4a. The slide base 4 is provided with a plurality of guide holes 4b in the vertical direction, and the lower ends of the auxiliary sliders 5 are slidably provided in the guide holes 4b in the vertical direction. The upper end sides of these auxiliary sliders 5 are fitted into the nozzle holder 6 so that the nozzle holder 6 moves up and down with respect to the slide base 4.

  A bracket 7 is fixed to the upper surface of the nozzle holder 6 by stopper bolts 8. The bracket 7 is urged downward by a spring 10 disposed between the bracket 7 and a stopper bracket 9 fixed to the slide base 4. An adjustment screw 11 is screwed into the stopper bracket 9, and the lower end of the adjustment screw 11 is in contact with the upper surface of the stopper bolt 8.

  A through hole 13 is provided in the slide base 4 in the vertical direction, and a drive slider 14 is slidably provided in the through hole 13. The drive slider 14 has a constricted portion 14 a that is wider than the thickness of the bracket 7 at the top of the drive slider 14, and the constricted portion 14 a is loosely inserted into the U-shaped groove 7 a of the bracket 7. Further, a flange 14b is provided below the constricted portion 14a of the drive slider 14 on the flange. A spring 15 is interposed between the flange 14b and the bracket 7, and the upper surface of the bracket 7 is urged so as to be pressed against the upper end of the constricted portion 14a.

  A cam base 16 is fixed to the back side of the base plate 2. A motor 17 is provided on the cam base 16. The cam base 16 is provided with an elliptical cam 18 having a major axis and a minor axis apart from the motor 17, and is rotatably provided between a pulley 19 of the motor 17 and a pulley 20 of the cam 18. Is over. A cam follower 22 is brought into rolling contact with the cam 18, and the cam follower 22 is rotatably provided on a cam follower base 23.

  One end of a drive rod 24 is fitted to the cam follower base 23. The drive rod 24 passes through a bracket 25 and a base plate 2 fixed to the cam base 16 and is slidable in the vertical direction. The other end of the drive rod 24 is at the lower surface of the drive slider 14 and a contact portion 14c. It is in contact. One end of an auxiliary rod 26 is slidably fitted to the cam follower base 23 in parallel with the drive rod 24, and the other end of the auxiliary rod 26 is slidably provided through the bracket 25.

  A spring 27 is fitted to the drive rod 24 and the auxiliary rod 26, and these springs 27 are interposed in a compressed state between the bracket 25 and the cam follower base 23 so that the cam follower 22 is always in close contact with the cam 18. .

  The nozzle holder 6 is provided with a suction nozzle 28 serving as a workpiece feeding means, and a nozzle head 28a for sucking the workpiece w is provided at the lower end of the suction nozzle 28. The base plate 2 is provided with a notch 2a, and an appearance inspection unit 29 facing the nozzle head 28a is provided in the notch 2a. Further, a cradle 30 is provided to cover the appearance inspection unit 29. The upper surface of the cradle 30 and the upper surface of the base plate 2 are flush with each other, and a turntable 31 is rotatably provided adjacent to the upper surface of the cradle 30 and the base plate 2.

  On the outer peripheral portion of the turntable 31, there is provided a work storage portion 31a including a concave portion in which the work w is stored at equal intervals. The turntable 31 is intermittently rotated on the base plate 2 and the cradle 30 by a driving means (not shown) so as to face the nozzle head 28a at the intermittent stop position so that the work storage portion 31a shown in FIG. It has become. Furthermore, at the intermittent stop position of the turntable 31, the workpiece passage hole 30a provided in the receiving base 30, the workpiece storage portion 31a, and the nozzle head 28a are positioned on the same vertical line.

  As shown in FIGS. 3A to 3C, the appearance inspection unit 29 includes a plurality of light reflecting means 33, 34, 35 provided in the optical path case 32 and an illuminating means 36 that irradiates substantially parallel rays. An imaging means 37 is provided on the extended line of the optical path L formed by the appearance inspection unit 29 as shown in FIG.

  Note that the pivot shaft 4a of the slide base 4 is a fulcrum for rotating the slide base 4 in the event of a malfunction in the appearance inspection unit 29 or the like. Normally, the slide base 4 is fixed to the base plate 2. Yes.

  Next, the operation of the appearance inspection apparatus 1 configured as described above will be described.

  As shown in FIG. 1, the cam 18 is formed in an elliptical shape having a major axis and a minor axis. The cam follower base 23 is urged by a spring 27 so that the cam 18 and the cam follower 22 are in elastic contact with each other. In this state, when the motor 17 rotates intermittently, the cam 18 rotates intermittently in the direction of the arrow through the pulley 19, the belt 21, and the pulley 20 every 90 °, and intermittently stops at the long diameter portion and the short diameter portion of the cam 18. Due to the difference in diameter between the long diameter portion and the short diameter portion of the cam 18, the cam follower 22 reciprocates in the vertical direction, and accordingly, the cam follower base 23, the drive rod 24 and the auxiliary rod 26 reciprocate in the vertical direction.

  As the cam follower 22 makes rolling contact from the longer diameter side to the shorter diameter side of the cam 18, the drive rod 24 is urged by the spring 27 and slides downward. As the drive rod 24 slides downward, the bracket 7 urged by the spring 10 and the drive slider 14 urged by the spring 15 slide downward to make contact between the lower surface of the drive slider 14 and the upper surface of the drive rod 24. The contact portion 14c always comes into close contact and slides.

When the cam follower 22 moves from the short diameter side to the long diameter side of the cam 18, the drive rod 24 slides upward to push up the drive slider 14, and the bracket 7 is pushed up accordingly. The upper limit of the bracket 7 is set so that the adjustment screw 11 and the stopper bolt 8 abut so that the tip of the nozzle head 28 a is flush with the lower surface of the slide base 4 near the nozzle head. As a result, when the work w is conveyed as shown in FIG. 2 due to the rotation of the turntable, it can pass stably because there is no step, and the tip of the nozzle head 28a is closest to the work w, so that it can be effectively attracted. it can.
Furthermore, since the constricted portion 14a of the drive slider 14 is provided so as to be wider than the thickness of the bracket 7, even if the bracket 7 is regulated by the adjustment screw 11 and stops at the upper limit position, the drive slider 14 is biased by the spring 15. Against this, it is possible to slide further by the stroke difference.

  The nozzle holder 6 fixed to the bracket 7 slides vertically with respect to the slide base 4 by a plurality of auxiliary sliders 5 and moves up and down. Since the slide base 4 and the base plate 2 are set in parallel, the nozzle holder 6 moves vertically up and down also with respect to the base plate 2. The suction nozzle 28 that moves vertically up and down with respect to the base plate 2 by the vertical movement of the nozzle holder 6 is connected to a negative pressure generating source (not shown), and the nozzle head 28a is always at negative pressure.

  As shown in FIG. 2, the workpiece w is stored in the workpiece storage portion 31a of the turntable 31 that intermittently rotates on the base plate 2, and the workpiece w is conveyed to the appearance inspection portion 29 provided facing the nozzle head 28a. As a result, the workpiece w is attracted and held by the nozzle head 28a, which is always negative pressure. When the workpiece w is sucked and held by the nozzle head 28a, the cam 18 rotates 90 ° and stops at the short diameter position, the nozzle head 28a sucking the workpiece w descends and the workpiece passage hole provided in the cradle 30 is provided. The workpiece w is moved from 30 a to the appearance inspection unit 29 provided in the base plate 2.

  As shown in FIGS. 3 (a) to 3 (d), the appearance inspection unit 29 reflects the substantially parallel light rays emitted from the illumination unit 36 by the plurality of light reflection units 33, 34, and 35 provided in the optical path case 32. To form an optical path L. That is, when the workpiece w attracted and held by the nozzle head 28a and moved to the appearance inspection unit 29 is put into the optical path L and irradiated with parallel rays from the back, an optical path L including the silhouette of the workpiece w is formed. As shown in FIG. 1A, the silhouette of the workpiece w is imaged by the imaging means 37 provided behind the optical path L, and transmitted to a control unit (not shown) for analysis.

The surface irradiated with the parallel rays of the workpiece w shown in FIG. 3 is the D-plane direction that cannot be inspected due to the wall surface of the workpiece storage portion 31a shown in FIG. As a result, a silhouette image of the workpiece w in the D plane direction shown in FIG. 2 is obtained in the imaging means 37. From this silhouette image, for example, abnormality such as bending of electrodes wa provided at both ends of the workpiece w can be inspected. That is, the silhouette image method can be used for inspection even when the workpiece surface and the electrode wa are not on the same plane as the workpiece w in FIG.
By the above, the external appearance inspection from four surfaces can be performed together with the A to C surfaces that can be inspected in the state of being stored in the work storage portion 31a of the turntable 31.

  When the appearance inspection of the D surface is completed, the cam 18 rotates 90 ° again and stops on the longer diameter side, whereby the nozzle head 28a rises and the workpiece w returns to the workpiece storage portion 31a of the turntable 31, and at the same time, The table 31 rotates intermittently, scrapes the workpiece w from the nozzle head 28a, and is conveyed to the next process.

  If the parallel light beam used for this inspection is manufactured by a conventional lens system, it becomes very expensive. Then, when the object workpiece | work w was as small as about 1 mm in length, it examined using LED.

FIG. 4A shows a basic form of light refraction. When light is incident on the medium B from the medium _A , if the angles with respect to the normal C are θ _A and θ _B , the relative refractive index n _AB is obtained from Snell's law. n _AB = n _B / n _A = sin θ _A / sin θ _B (n _A , n _B : refractive index of the medium)
If A is air, n _A ≈1 and n _B > 1
sinθ _A / sinθ _B > 1, ie, θ _A > θ _B
FIG. 4B shows a result of applying this result to the LED 40 in which the light projecting surface 41 is substantially spherical and filled with resin. That is, when the result of Snell's law is applied, when the light emitting unit 42 is located at the rear part of the sphere center o of the light projecting surface 41, the light projection X exiting the light emitting unit 42 is refracted by the light projecting surface 41 and LED However, the projection X does not intersect the optical axis Y in theory. Therefore, it can be said that the light projection in the vicinity of the optical axis Y is close to parallel rays.

In addition, since the parallel light is slightly shifted depending on the size of the light emitting portion 42, the light emitting portion 42 is preferably smaller. Although the LED has been described as the illuminating means 36, any other means can be applied as long as it satisfies the configuration shown in FIG. The characteristics of the light source of the illumination means 36 are summarized as follows:
(1) The light emitting part is preferably as small as possible.

  (2) The light projecting surface is preferably convex, and it is preferable that the light emitting portion is on the opposite side of the light projecting surface from the convex center o.

  (3) It is preferable that the vicinity of the light projection surface is filled with the same medium.

  (4) Since the light projection increases in parallel as it approaches the optical axis Y, the inspection accuracy improves as the inspection target workpiece w decreases.

The above is a preferable condition in the theoretical case, but in practice, some turbulence occurs due to the structure of the LED 40. Since this diffused light diffuses near the proportion of the LED 40, if there is a problem, it can be prevented by providing a diaphragm 50 having a diaphragm hole 50a in front of the LED 40 with the optical axis aligned as shown in FIG.
5A and 5B show a second embodiment of the appearance inspection apparatus of the present invention, in which FIG. 5A is a perspective view, and FIG. 5B is an enlarged perspective view of the main part of FIG. In FIG. 5, the configuration in which the suction nozzle 28 is vertically moved is the same as that of the first embodiment, and thus the description thereof is omitted. In the present embodiment, in the appearance inspection unit 43 of the workpiece w sucked and held by the nozzle head 28a, the imaging means 44a, 44b, 44c, 44d, and 44e provided on the five surfaces other than the suction surface, respectively. Thus, each surface is imaged.

  It is assumed that each imaging means 44a, 44b, 44c, 44d, 44e includes illumination means (not shown).

  The workpieces w supplied by the workpiece supply means 45 are stored in a plurality of workpiece storage portions 31a provided on the peripheral portion of the turntable 31 that rotates intermittently, and conveyed to an appearance inspection portion 43 provided opposite to the nozzle head 28a. As a result, the workpiece w is attracted and held by the nozzle head 28a, which is always negative pressure.

  When the workpiece w is sucked and held, the suction nozzle 28 is lowered to move the workpiece w from the workpiece storage portion 31a to the approximate center position of the appearance inspection portion 43 provided in the space on the lower surface side of the turntable 31. ing.

  Data picked up by the image pickup means 44a, 44b, 44c, 44d, 44e provided to face each surface excluding the upper surface attracted by the nozzle head 28a of the work w moved to the approximate center of the appearance inspection unit 43. At the same time as being transmitted to a control unit (not shown), the suction nozzle 28 rises to show the workpiece w again in the workpiece storage unit 31a.

  When the suction nozzle 28 reaches the upper limit position, the turntable 31 rotates intermittently, scrapes the workpiece w from the nozzle head 28a, and is transported to the next process.

  In addition, about the upper surface of the workpiece | work w adsorb | sucked by the nozzle head 28a, the image of all 6 surfaces can also be obtained by image-capturing separately by the imaging means which is not shown in figure before or after that.

  In the first embodiment, mirrors are used as the plurality of light reflecting means 33, 34, and 35. However, reflection by a prism may be used, and reflection of light by the plurality of mirrors is a design means. It is not related to the number of people.

  Furthermore, although the cam 18 and the cam follower 22 are used for the vertical movement of the suction nozzle 28, this is to alleviate the rapid movement of the suction nozzle 28. The type of actuator is not limited.

  In the second embodiment, the appearance inspection unit 43 images five surfaces, but the lower surface may be imaged simultaneously at a position where the upper surface is imaged by an imaging unit (not shown).

  The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, the constituent elements over different embodiments may be combined.

BRIEF DESCRIPTION OF THE DRAWINGS The 1st Embodiment of the external appearance inspection apparatus of this invention is shown, (a) is the partially sectional front view, (b) is an arrow line view along AA of Fig.1 (a). The perspective view which expanded the work storage part which shows the same embodiment. FIG. 2 is an enlarged view of a main part of FIG. 1, showing (a) a plan view, (b) a side view, (c) a front view, and (d) a perspective view of optical path formation. The same embodiment is shown, (a) (b) Explanatory drawing of an illumination means. The 2nd Embodiment of the external appearance inspection apparatus of this invention is shown, (a) is a perspective view, (b) is the perspective view which expanded the principal part of (a). The perspective view of the conventional external appearance inspection apparatus.

Explanation of symbols

28 ... Suction nozzle (delivery means), 31 ... Turntable, 31a ... Work storage part, 36 ... Illumination means, 37 ... Imaging means (inspection means)

Claims (12)

A turntable having a plurality of workpiece storage units for storing and transporting workpieces one by one on the outer periphery;
Sending means for sucking and holding the work stored in the work storage unit and sending it to the external space of the turntable;
Comprising inspection means for inspecting the appearance of the workpiece sent from the turntable,
After rotating the turntable and positioning the work storage part at a predetermined position, the work in the work storage part is sent out to the external space of the turntable by the sending means, and the appearance of the work is inspected by the inspection means. An appearance inspection apparatus characterized by:   The appearance inspection apparatus according to claim 1, wherein the delivery unit is a suction nozzle that sucks the workpiece and moves in a vertical direction with respect to the turntable surface.   3. The appearance inspection apparatus according to claim 2, wherein the suction nozzle is driven by a vertical movement mechanism including a cam having a short diameter and a long diameter, and a cam follower that moves up and down as the cam rotates.   The appearance inspection apparatus according to claim 2, wherein the suction nozzle is driven by a vertical movement mechanism including a crank mechanism.   The appearance inspection apparatus according to claim 2, wherein the suction nozzle is driven by a vertical movement mechanism including a screw feed mechanism.   The inspection means includes an illuminating means for irradiating the work with a substantially parallel light beam, a plurality of light reflecting means for reflecting the substantially parallel light beam, and an imaging means, and the work is located in the parallel light beam. The appearance inspection apparatus according to claim 1, wherein the silhouette image of the workpiece is captured by the imaging unit.   The inspection means includes a plurality of imaging means provided to face each surface other than the suction surface by the sending means of the work that is sucked and held by the sending means and sent to the external space of the turntable. The appearance inspection apparatus according to claim 1, characterized in that:   The illumination means includes a light projecting portion having a substantially spherical convex shape, and the light emitting portion is on the optical axis on the opposite side of the spherical surface with respect to the spherical center of the light projecting portion. The appearance inspection apparatus according to claim 6.   9. The appearance inspection apparatus according to claim 8, wherein an aperture is provided on the front surface of the light projecting unit so as to match an optical axis.   The visual inspection apparatus according to claim 8, wherein the light projecting unit is an LED having the configuration according to claim 8.   The appearance inspection apparatus according to claim 6, wherein the light reflecting means is a mirror.   7. The appearance inspection apparatus according to claim 6, wherein the light reflecting means is a prism.

Images