JP6040387B1 - Lens inspection device - Google Patents

Abstract

A lens is inspected with high accuracy and high efficiency. A lens inspection device includes a plurality of posture adjustment units, a lens supply region for supplying a lens to the posture adjustment unit, and a lens unloading device for unloading the lens from the posture adjustment unit. The transfer device 60 that moves the plurality of posture adjustment units 10 so as to pass through the lens supply region IN and the lens carry-out region OUT, and during the movement of the posture adjustment unit 10 from the lens supply region IN to the lens carry-out region OUT The posture adjustment unit 10 inspects the lens L while individually controlling the posture of the lens L in each of the plurality of inspection regions A1 to A6. [Selection] Figure 1

Description

  The present invention relates to a lens inspection device for inspecting a lens.

  In recent years, lens modules such as digital cameras, video cameras, camera-equipped mobile phones, smartphones, and in-vehicle cameras have been remarkably reduced in size and increased in accuracy. Along with this, the lenses incorporated in the lens modules are also required to be smaller and have higher performance.

  For this type of lens, generally, a molded lens manufactured by press molding of a glass material, a resin lens manufactured by injection molding of a resin material, or the like is used. Such a lens has quality degradation factors such as shape accuracy, scratches, cracks, foreign matter, and bubbles. Therefore, it is necessary to inspect for each lens.

  Conventionally, a lens is held with a finger or tweezers, and in this state, the presence or absence of scratches, cracks, foreign matter, bubbles, or the like is determined. However, with the miniaturization and high precision of lenses, even a scratch of about several μm may affect the performance of the lens, and therefore, automation of the inspection process by the lens inspection apparatus has been promoted.

  A conventional lens inspection apparatus picks up a plurality of lenses placed on a transport tray by a lens transport mechanism and supplies the picked-up lens to an adjustment stage (inspection stage). On the adjustment stage, the lens is held again, and the lens is moved above the CCD camera to take an image of the appearance and inspect for scratches and the like. The lens that has been inspected is carried out by the lens transport mechanism. In order to increase inspection efficiency, it has also been proposed to perform inspection using two adjustment stages (see Patent Document 1).

JP 2006-329714 A

  However, since the conventional lens inspection apparatus performs all appearance inspections at each adjustment stage, there is a problem that the lens stays on the adjustment stage for a long time and inspection efficiency is poor. Also, if you prepare multiple adjustment stages and try to increase the inspection efficiency, the length of the lens transport mechanism that loads and unloads the lens with respect to each adjustment stage will increase, resulting in an increase in the size of the entire inspection apparatus was there.

  In addition, in the conventional lens inspection apparatus, if an error occurs in the output data of the lens inspection due to an apparatus error somewhere on the plurality of adjustment stages or foreign matter adhering to the CCD camera, which adjustment is performed. There was a problem that it took a long time to find out whether a trouble occurred on the stage, and the entire inspection apparatus had to be stopped until the cause was clarified.

  Furthermore, since the conventional lens inspection apparatus has a structure in which the entire lens is collectively imaged with a single CCD camera, for example, it is not possible to photograph well the wound surface and foreign matter on the curved surface around the lens (region close to the outer periphery). There was a problem. The size of the scratch / foreign matter is also different from the actual size due to the influence of the imaging angle, and there is a problem that the pass / fail criterion is ambiguous.

  In view of such circumstances, the present invention intends to provide a lens inspection device and the like that can shorten the inspection time while increasing the inspection accuracy of the lens.

  The present invention that achieves the above object is a lens inspection device for inspecting a lens, comprising a plurality of posture adjustment units, a lens supply device that supplies the lenses to the posture adjustment unit in a lens supply region, and a lens unloading device. A lens carry-out device for carrying out the lens from the posture adjustment unit in a region, a transfer device for moving the plurality of posture adjustment units so as to pass through the lens supply region and the lens carry-out region, and the posture adjustment unit. A plurality of inspection areas existing while being moved from the lens supply area to the lens carry-out area; and an imaging device that is provided in each of the plurality of inspection areas and images the lens. Respectively, a holding unit that holds the periphery of the lens, and a posture adjusting machine that adjusts the posture of the holding unit. Have, the posture adjusting unit in each of a plurality of the inspection areas, and performs posture control of the lens by the position adjusting mechanism, a lens inspection apparatus.

  In relation to the lens inspection apparatus, the posture adjustment unit holds the lens in different postures in the plurality of inspection regions.

  In relation to the lens inspection apparatus, the posture adjustment unit holds the lens so that the optical axis directions are different from each other in the plurality of inspection regions.

  In relation to the lens inspection device, the posture adjustment unit positions the lens posture a plurality of times so that the optical axis directions are different from each other in the specific inspection region. The lens is imaged.

  In relation to the lens inspection device, the posture adjustment unit positions the lens a plurality of times so that the centers of focus of the imaging device are different from each other in the specific inspection region, and The imaging device images the lens.

  In relation to the lens inspection device, the lens conveyed by the transfer device is focused and imaged in different regions by the plurality of imaging devices arranged in the plurality of inspection regions. And

  In relation to the lens inspection apparatus, a background plate is disposed on the opposite side of the imaging surface of the lens in each of the plurality of inspection regions.

  In relation to the lens inspection device, an illumination device is disposed in each of the plurality of inspection regions.

  The present invention that achieves the above object is a lens inspection apparatus for inspecting a lens, and includes a holding unit that holds a periphery of the lens, and a posture adjusting unit that has a posture adjusting mechanism that adjusts the posture of the holding unit, An image pickup device that is arranged in the vicinity of the posture adjustment unit and picks up the lens, and the posture adjustment mechanism includes an X shift mechanism that moves the holding portion in the X direction on the XY plane, and the holding portion. A Y shift mechanism that moves the holding portion in the Y direction on the XY plane, a Z shift mechanism that moves the holding portion in the Z axis direction perpendicular to the XY plane, and the holding portion that is tilted around the X axis. A lens comprising: an X tilt mechanism that rotates; a Y tilt mechanism that tilts or rotates the holding portion around the Y axis; and a Z tilt mechanism that tilts or rotates the holding portion around the Z axis. Inspection device A.

  According to the present invention, it is possible to perform lens inspection with high inspection accuracy and in a short time.

It is a top view explaining the outline | summary of the same lens inspection apparatus. It is the (A) top view and (B) side view of the lens. It is a side view explaining the attitude | position adjustment unit of the lens inspection apparatus. It is a top view explaining the same attitude | position adjustment unit. It is a partial enlarged plan view explaining the lens holding operation of the same posture adjustment unit. It is a partial expanded side sectional view explaining the lens holding operation of the same posture adjustment unit. It is a partial enlarged plan view for explaining the operation of the lens supply region. It is a partial expanded side view explaining operation | movement of a lens supply area | region. (A) is a top view which shows a test chart, (B) is explanatory drawing which shows typically the state which image | photographed the test chart with the imaging device. (A)-(D) is a graph which shows the change of the shading difference value of the surrounding pixel of an imaging device, (E) is a figure for demonstrating arrangement | positioning of the surrounding pixel on an imaging device, (F) and (G) is a diagram for explaining a trigonometric function for calculating a tilt correction amount. (A)-(C) is a figure for demonstrating the change of the best focus position by the tilt control from the 1st time to the 3rd time. (A) The top view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a 1st test | inspection area | region, (B)-(D) is sectional drawing of the BB of the lens of (A). (A) The top view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a 2nd test | inspection area | region, (B)-(D) are sectional drawings of BB of the lens of (A). (A) The top view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a 3rd test | inspection area | region, (B)-(D) are sectional drawings of BB of the lens of (A). (A) The top view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a 4th test | inspection area | region, (B)-(D) is sectional drawing of the BB of the lens of (A). (A) The top view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a 5th test | inspection area | region, (B)-(D) is sectional drawing of the BB arrow of the lens of (A). (A) The top view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a 6th test | inspection area | region, (B)-(D) is sectional drawing of the BB of the lens of (A). (A) The side view which shows the test | inspection area | region of a lens for demonstrating a test | inspection process to a lens carrying-out area | region, (B)-(D) are sectional drawings of the lens of (A). It is a side view explaining the other structural example of the same lens inspection apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In this specification, one direction in the horizontal plane is defined as the X direction, a direction perpendicular to the X direction in the horizontal plane is defined as the Y direction, and a direction perpendicular to the X direction and the Y direction is defined as the Z direction.

  As shown in FIG. 1, the lens inspection apparatus 1 includes a plurality of posture adjustment units 10, a component supply device 79A that supplies the lens L to the posture adjustment unit 10 in the lens supply region IN, and a posture adjustment unit in the lens unloading region OUT. A lens unloading device 79B for unloading the lens L from the lens 10, a transfer device 60 for moving the plurality of posture adjustment units 10 so as to pass through the lens supply region IN and the lens unloading region OUT, and a controller 90 for controlling the whole. .

  In the lens supply area IN, a lens tray SL in which a plurality of lenses L are stocked is arranged. The lens supply device 79 </ b> A sequentially takes out the lenses L from the tray and supplies them to the posture adjustment unit 10.

  In the lens carry-out area OUT, a collection tray OT that collects the lenses L that pass the inspection and an error tray ET that collects the lenses L that fail the inspection are arranged. The lens carry-out device 79B picks up the lens L from the attitude adjustment unit 10 and distributes it to the collection tray OT and the error tray ET.

  The transfer device 60 is a so-called turret mechanism, and has a rotary table that is rotated by a drive source such as a motor (not shown). Around the rotary table, a plurality (eight in this case) of posture adjustment units 10 are arranged at equal intervals (45 ° intervals) in the circumferential direction. In this embodiment, the lens supply region IN and the lens carry-out region OUT are adjacent to each other with a phase difference of 45 ° in the circumferential direction, and the transfer device 60 revolves each posture adjustment unit 10 by 360 ° to revolve the posture. The adjustment unit 10 is transferred from the lens supply area IN to the lens carry-out area OUT and returned to the lens supply area IN again.

  There are a total of six first to sixth inspection areas A1 to A6 between the lens supply area IN and the lens carry-out area OUT, and the posture adjustment unit 10 passes through these inspection areas A1 to A6. Various inspections are performed by changing the posture of the lens L in various ways. That is, on the transfer path of the transfer device 60, the lens supply area IN, the first to sixth inspection areas A1 to A6, and the lens carry-out area OUT are arranged at equal intervals, and eight posture adjustment units. 10 stops in each area at the same time. In the present embodiment, the lens L is inspected also in the lens supply area IN and the lens carry-out area OUT.

  Each posture adjustment unit 10 passes through the lens supply area IN, the first to sixth inspection areas A1 to A6, and the lens carry-out area OUT from the upstream side toward the downstream side. Since these areas are arranged at intervals of 45 °, the eight posture adjustment units 10 stop simultaneously in any of these areas, and the processes of the respective areas are performed simultaneously.

  FIG. 2 shows a lens L to be inspected by the lens inspection apparatus 1. This lens L has a light incident side surface LA and a light output side surface LB, and is a biconvex lens in which both surfaces are convex in the optical axis direction. Further, a convex portion LT that protrudes outward in the radial direction is formed on the outer peripheral edge of the lens L. The convex portion LT is used to determine a reference position in the circumferential direction of the lens L. The shape of the lens L varies, and examples include a plano-convex lens, a convex meniscus lens, a biconcave lens, a plano-concave lens, and a concave meniscus lens.

  As shown in FIGS. 3 and 4, the posture adjustment unit 10 includes a holding portion 20 that holds the lens L, and a posture adjustment mechanism 40 that is disposed on the base 5 and adjusts the posture of the holding portion 20.

  The holding unit 20 is a so-called chuck mechanism, and the first arm 22 and the second arm 24 extending in the radial direction of the rotary table, and the first arm 22 and the second arm 24 are connected in a tangential direction or a circumferential direction of the rotary table. And an arm moving part (first opening / closing mechanism) 26 that opens and closes. The arm moving unit 26 is a slide guide, and slides the first arm 22 and the second arm 24 in the horizontal direction so as to approach and separate from each other. The opening / closing method may employ other methods such as turning.

  As shown in FIG. 5A, partial arc-shaped concave portions 22 </ b> A and 24 </ b> A for holding the lens L are formed at the tips of the first arm 22 and the second arm 24. Therefore, the lens L is stably held by bringing the concave portions 22A and 24A into contact with the outer peripheral edge of the lens L. Further, a relief portion 25 </ b> A is formed at the tips of the first arm 22 and the second arm 24. The escape portion 25A is a notch that extends further outward in the radial direction from the recesses 22A and 24A. As shown in FIG. 5C, when the lens L is viewed from the optical axis direction in a state where the lens L is held by the first arm 22 and the second arm 24, the lens L is formed around the lens L by the escape portion 25A. Interference between the projected portion LT and the arms 22 and 24 is avoided, and positioning errors can be reduced. Here, the case where the escape portion 25A is configured by a notch is illustrated, but as shown in FIG. 5B, the first arm 22 and the second arm 24 escape in a space where the first arm 22 and the second arm 24 do not exist (for example, the gap 25B). The convex portion LT can be positioned there. In this example, two arms are used, but a structure is adopted in which four arms with different phases in the circumferential direction are brought closer to the inside in the radial direction and the lens L is held by the tip of each arm. You may do it.

  As shown in FIG. 6, the portion that holds the lens L in the holding portion 20 is configured by a very thin member when viewed from the horizontal direction. In this way, when holding the lens L, the holding portion 20 does not protrude from the upper end surface of the lens L, or even if it protrudes, the amount of protrusion is limited to within a few millimeters (for example, within 5 mm). This prevents the holding unit 20 from getting in the way during inspection.

  3 and 4, the posture adjustment mechanism 40 supports the holding unit 20 and can individually adjust the position and posture of the holding unit 20, and is fixed to the base 5. 40YS, an X shift mechanism 40XS fixed to the slide member of the Y shift mechanism 40YS, a Z shift mechanism 40ZS fixed to the slide member of the X shift mechanism 40XS, and a slide member of the Z shift mechanism 40ZS. Y tilt mechanism 40YT, Z tilt mechanism 40ZT fixed to the tilt table of Y tilt mechanism 40YT, and X tilt mechanism (rotation mechanism) 40XT fixed to the tilt table of Z tilt mechanism 40ZT. The holding unit 20 is installed on the tilt table of the X tilt mechanism 40XT. Note that the X axis, Y axis, and Z axis, which are the rotation centers of the tilt, are set to the approximate center of the lens portion LL.

  Therefore, the attitude adjustment mechanism 40 is configured by stacking X, Y and Z shift mechanisms 40XS, 40YS, and 40ZS along the Z-axis direction, and further X, Y, and Z tilt mechanisms 40XT toward the radially outer side of the rotary table. , 40YT, 40ZT are stacked. The Y and Z tilt mechanisms 40YT and 40ZT are so-called gonio stages.

  Although not particularly illustrated, the drive mechanism of the Y shift mechanism 40YS includes an elastic member (for example, a spring or rubber) that connects the base side and the slide member and biases the slide member to one side, and the bias of the elastic member. It is comprised by the drive source (for example, a servomotor or a solenoid) which moves a slide member with a cam etc. against this. This structure is similarly applied to the Y and Z shift mechanisms 40YS and 40ZS.

  Although not particularly illustrated, the drive structure of the X tilt mechanism 40XT includes an elastic member (for example, a spring or rubber) that connects the base side and the tilt table to swing the tilt table to one side, and an urging force of the elastic member. Against this, it is constituted by a drive source (for example, a servo motor or a solenoid) that swings the tilt table to the opposite side by a cam or the like. This structure is similarly applied to the Y and Z tilt mechanisms 40YT and 40ZT. As described above, when the elastic member, the cam, and the like are combined as the drive structure, the posture adjusting mechanism 40 corresponding to 6 axes can be driven with a very compact configuration as a whole. In addition, this drive mechanism can also use a ball screw etc., for example.

  Next, operations in each region of the lens inspection apparatus 1 will be described. In the present embodiment, as shown in FIG. 2, the surface of the lens L is divided into nine places in a lattice shape, and inspection is performed for each of the first to ninth sections LK1 to LK9.

  Lens supply area IN: As shown in FIGS. 7A to 7C, the lens L is supplied from the lens supply device 79A to the posture adjustment unit 10. Note that an imaging device KIN is disposed below the lens supply region IN, and the holding posture of the lens L in the lens supply device 79A can be captured by the imaging device KIN. The lens supply device 79A rotates the lens L in the θ direction based on the data of the imaging device KIN, thereby controlling the rotation so that the convex portion LT is positioned at the escape portion 25A of the holding portion 20, and then the posture. The lens L is supplied to the adjustment unit 10.

  As shown in FIG. 8, the lens supply device 79A sucks the top surface or the bottom surface of the lens L with the vacuum chuck BC and conveys it to the posture adjustment unit 10 while controlling the rotation. On the other hand, the posture adjustment unit 10 holds the lens L sucked and held by the vacuum chuck BC with the holding unit 20. After holding the lens L by the holding unit 20, the negative pressure of the vacuum chuck BC is released and retracted.

  Further, in the lens supply area IN, the center and angle of the optical axis of the lens L and the axial position of the lens L are detected (this is called tilt adjustment and focus adjustment). Specifically, as shown in FIG. 3, an optical axis adjusting device (chart device) W is disposed above the lens supply region IN, and an imaging device MIN is disposed below. When the lens L is inserted between the optical axis adjustment device W and the imaging device MIN, the test chart image of the optical axis adjustment device W is taken by the imaging device MIN via the lens L. Using this imaging result (imaging information), the attitude adjustment mechanism 40 performs tilt control and various controls on the holding unit 20 to correctly detect the optical axis of the lens L. As a result, the posture adjustment mechanism 40 causes the optical axis of the lens L to be parallel to the inspection reference axis of each inspection region of the lens inspection device 1, and the optical axis center of the lens L is the inspection region of the lens inspection device 1. The posture can be controlled to match the inspection center. In addition, the position of the lens L in the optical axis direction can be detected.

  FIG. 9A shows an example of a test chart F in the optical axis adjusting device (chart device) W. On the test chart F, a striped pattern F1 is drawn. In the video obtained by photographing the striped pattern F1, for example, when the focus is matched, the density of the video (the difference between the black and white of the output signal) becomes large, and when the focus is mismatched (blurred), the density is shaded. Becomes smaller. Thereby, the position of the lens L in the optical axis direction can be detected. Further, the test chart F has a cross pattern F2 for determining the center thereof. Thereby, the plate center F3 can be determined. Further, the rotation angle around the Z axis can be determined by the angle of the stripe pattern F1 or the cross pattern F2.

  FIG. 9B schematically shows a state where the test chart F is photographed by the imaging device MIN. A data area (frame) photographed by the imaging device MIN is defined as G, and is defined as a frame center E of the data area G, and there are a plurality of (four in this case) three or more surroundings with respect to the frame center E. A pixel group is defined as peripheral pixels A to D. The correction condition calculation device calculates errors Gxs and Gys in the XY directions between the frame center E and the plate center F3 projected in the data area G. Also, an error Gzt around the Z axis is calculated from the difference between the intersecting pattern F2 displayed in the data area G and the frame reference lines KX and KY in the X direction and Y direction of the data area G. These errors Gxs, Gys, and Gzt are correction conditions for X shift, Y shift, and Z tilt (rotation around the Z axis) for aligning the center of the lens L with the center of the optical axis adjustment device W.

  Here, the errors Gxs and Gys in the XY direction between the frame center E and the plate center F3 projected in the data area G are used as the X shift and Y shift correction conditions, but the present invention is not limited to this. Not. For example, the center of the lens L is the brightest position in the image of the imaging device MIN, and becomes darker in a stepwise manner as it spreads around. Therefore, by analyzing the image captured by the imaging device MIN, the brightest region in the data region G is determined as the center (lens center) FM of the lens L, and the lens center FM and the frame of the data region G are determined. It is also preferable that the errors Gxs and Gys in the X direction and the Y direction with respect to the center E are used as correction conditions for the X shift and the Y shift. This technique is effective when the lens center of the lens L does not coincide with the center of the focus determination pattern plate F.

  When performing X, Y tilt adjustment or focus adjustment, the posture adjustment unit 10 raises the lens L in the Z-axis direction (moves in the positive direction), while the test chart F is captured at a plurality of locations in the Z-axis direction by the imaging device MIN. Take an image. The correction condition calculation device calculates a density difference value (brightness / darkness difference value) BW in the peripheral pixels A to D, and calculates a tilt error from an output fluctuation of the density difference value BW along the movement in the Z direction. Specifically, as shown in FIGS. 10A to 10D, for each of the peripheral pixels A to D, the peak point of the density difference value (light / dark difference value) BW accompanying the movement in the Z direction (this is the best). AZ, ZB, ZC, and ZD of the Z direction position (referred to as the Z direction focus position) of the focus) are determined. When the best focus timing, that is, the Z-direction focus positions ZA, ZB, ZC, and ZD are shifted from each other in the peripheral pixels A to D, an angle difference is set between the optical axis of the imaging device MIN and the optical axis of the lens L. Therefore, the lens L is tilt-controlled around the Y axis and the X axis so that the Z-direction focus position almost coincides with all the peripheral pixels A to D.

  For example, as shown in FIG. 10E, the analysis is performed on the pixel A and the pixel B having the actual distance Xab in the X-axis direction, and the Z-direction focus position of the pixel A and the pixel B as shown in FIGS. Assume that the actual distance Zab (= ZA−ZB) in the Z-axis direction is calculated as the difference between the two. By calculating the inclination angle of the hypotenuse of the right triangle whose adjacent sides are these two actual distances Xab and Zab, the tilt deviation amount Gyt of the optical axis around the Y axis can be determined by the relational expression of FIG. Similarly, as shown in FIG. 10E, the pixels A and C having the actual distance Yac in the Y-axis direction are analyzed, and the Z-direction focus of the pixels A and C is obtained as shown in FIGS. Assume a case where an actual distance Zac (= ZA−ZC) in the Z-axis direction as a position difference is calculated. Further, the inclination angle Gxt of the optical axis around the X axis is determined by calculating the inclination angle of the hypotenuse of the right triangle having the two actual distances Yac and Zac as the adjacent sides by the relational expression in FIG. it can. These tilt shift amounts Gyt and Gxt are correction conditions for Y tilt and X tilt.

  Here, the case where the correction conditions for the X tilt and the Y tilt are calculated using the Z-direction focus positions ZA, ZB, and ZC of the three pixels A to C is illustrated. That is, when calculating the X tilt and the Y tilt, it is possible to use at least three peripheral pixels A to C constituting the apex of the triangle. On the other hand, it is also possible to calculate using four pixels A to D or more. For example, as shown in FIG. 10E, the average value (ZA + ZC) / 2 of the Z-direction position of the pixel A and the pixel C existing at the same position in the X direction, and the pixel B existing at the same position in the X direction Using the average value (ZB + ZD) / 2 of the pixels D, the amount of tilt deviation around the Y axis (Y tilt correction condition) may be calculated. The same applies when calculating the amount of tilt deviation around the X axis.

  The average value of the Z-direction focus positions of the peripheral pixels A to D is the final Z shift setting condition Gzt. Since the Z shift is an axis for performing a search operation to calculate other correction values, the Z shift is not a concept of correction conditions but a final setting condition.

  As a result, correction conditions for the X shift, Y shift, Z shift, X tilt, Y tilt, and Z tilt (setting conditions for the Z shift) can be output by calculating the correction conditions using the optical axis adjustment device W. it can. That is, the optical axis of the lens L and the position of the lens L in the optical axis direction can be accurately detected. In addition, here, when determining correction conditions for X tilt and Y tilt, a case where geometric calculation is performed using a trigonometric function using a Z-direction focus position difference and an inter-pixel distance between a plurality of pixels is illustrated. However, it goes without saying that the present invention is not limited to this method.

  Furthermore, here, after moving the lens L in the Z-axis direction using the attitude adjustment unit 10 based on the first Z shift correction condition, the test chart F is imaged again using the optical axis adjustment device W, The same Z shift correction condition and tilt correction condition as described above are calculated again. This process is called focus control.

  Specifically, after calculating the second Z shift correction condition, the controller 90 determines whether or not the second Z shift correction condition is within an allowable range by a built-in determination unit. That is, it is determined whether or not the Z shift correction amount is within an allowable range. If it is determined that the second and subsequent Z shift correction conditions are within the allowable range of light irradiation, positioning is completed without performing the Z shift adjustment of the holding unit 20 according to the second Z shift correction condition. Let On the other hand, if the second Z shift correction condition is outside the allowable range, in order to repeat the above process, focus control is performed based on the second Z shift correction condition, and then the test chart is photographed again. That is, (1) execution of predetermined determination processing and setting processing regarding the recalculated Z shift correction condition, (2) Z shift adjustment of the holding unit 20 reflecting the results of the determination processing and setting processing, and (3) Z shift. Repeat the recalculation of the correction conditions.

  FIG. 10 shows a diagram in which the Z-direction focus positions of the peripheral pixels A to D analyzed by the controller 90 are displayed in an overlapping manner. 11A is after the first tilt correction, FIG. 11B is after the second tilt correction, and FIG. 11C is after the third tilt correction. In the first time, the Z-direction focus positions ZA to ZD are greatly shifted, but in the second time, the Z-direction focus positions ZA to ZD approach rapidly. In the third time, the Z-direction focus positions ZA to ZD almost coincide. In the third time, the amount of deviation of the Z direction focus positions ZA to ZD falls within the range of the predetermined range AP, so the focus control is completed. As can be seen from FIG. 11, the search range Zsr for imaging while moving the lens L in the Z direction needs to be set wide in the first time, but in the second and subsequent times, the Z-direction focus position ZA˜ It is preferable to set the ZD average value and the center as narrow, and the imaging time can be shortened. Of course, the imaging device MIN side may be moved in the Z-axis direction.

  Further, the lens supply area IN also serves as a lens inspection area (outer shape inspection area), and inspects the peripheral shape of the lens using an image of the lens L imaged by the imaging device MIN. For example, if the peripheral shape of the lens L is an ellipse, the peripheral edge of the lens L is chipped, or there is an error in the shape of the convex portion LT, and it deviates from a desired threshold value, judge.

  First inspection area A1: As shown in FIG. 12, the first imaging device M1 is disposed above the first inspection area A1. A monochrome (for example, white) background plate P1 is disposed on the opposite side of the first imaging device M1 with respect to the conveyed lens L. Further, the first illumination device S1 is disposed above the first inspection area A1, and the lens L is irradiated with light suitable for inspecting the surface for scratches and foreign matter.

  The first imaging device M1 detects a scratch or a foreign object on the upper surface of the lens L by photographing the upper surface of the lens L from above and analyzing the image. Specifically, here, the first imaging device M1 focuses each surface of the fourth section LK4, the fifth section LK5, and the sixth section LK6, which are part of the lens L, and the respective surface states. Image. At this time, as shown in FIGS. 12B to 12D, the perpendicular direction of the center of each section of each section LK4 to LK6 is parallel to the inspection reference axis J, and each section LK4 to The posture adjustment mechanism 40 is configured so that the section center of LK6 coincides with the imaging center of the first imaging device M1, and further, the surface thereof coincides with the focal position (focus point) of the first imaging device M1. The posture of the holding unit 20 is controlled. As a result, since the image of the upper surface of each of the sections LK4 to LK6 can be taken with high accuracy, it is possible to accurately detect a flaw or a foreign object. In particular, since the posture of the lens L is individually controlled so that the perpendicular direction of the surface of each of the sections LK4 to LK6 is parallel to the imaging axis of the first imaging device M1, scratches or foreign matters obtained from the image data are controlled. The dimensional accuracy is increased, and it is possible to accurately perform the pass / fail determination.

  Second inspection area A2: As shown in FIG. 13, the second imaging device M2 is disposed above the second inspection area A2. A monochrome (for example, white) background plate P2 is disposed on the opposite side of the second imaging device M2 with respect to the conveyed lens L. In addition, a second illumination device S2 is disposed above the second inspection area A2, and the lens L is irradiated with light suitable for inspecting the surface for scratches and foreign matter.

  The second imaging device M2 detects a scratch or a foreign matter on the upper surface of the lens L by photographing the upper surface of the lens L from above and analyzing the image. Specifically, here, the second imaging device M2 focuses on the surfaces of the first section LK1, the second section LK2, and the third section LK3, which are part of the lens L, and the respective surface states. Image. At this time, as shown in FIGS. 13B to 13D, the perpendicular direction of the center of each section of each section LK1 to LK3 is parallel to the inspection reference axis J and each section LK1 to LK1. The posture adjustment mechanism 40 is configured so that the division center of LK3 coincides with the imaging center of the second imaging device M2, and further, the surface thereof coincides with the focal position (focus point) of the second imaging device M2. The posture of the holding unit 20 is controlled. As a result, since the image of the upper surface of each of the sections LK1 to LK1 can be taken with high accuracy, it is possible to accurately detect a flaw or a foreign object. In particular, since the posture of the lens L is individually controlled so that the perpendicular direction of the surface of each of the sections LK1 to LK1 is parallel to the imaging axis of the second imaging device M2, scratches or foreign matters obtained from the image data are controlled. The dimensional accuracy is increased, and it is possible to accurately perform the pass / fail determination.

  Third inspection region A3: As shown in FIG. 14, the third imaging device M3 is disposed above the third inspection region A3. A monochrome (for example, white) background plate P3 is disposed on the opposite side of the third imaging device M3 with respect to the conveyed lens L. In addition, a third illumination device S3 is disposed above the third inspection region A3, and the lens L is irradiated with light suitable for inspecting the surface for scratches and foreign matter.

  The third imaging device M3 detects a scratch or a foreign matter on the upper surface of the lens L by photographing the upper surface of the lens L from above and analyzing the image. Specifically, here, the third imaging device M3 focuses on the surfaces of the seventh section LK7, the eighth section LK8, and the ninth section LK9, which are part of the lens L, and the respective surface states. Image. At this time, as shown in FIGS. 14 (B) to (D), the perpendicular direction of the section center of each surface of each section LK7 to LK9 is parallel to the inspection reference axis J, and each section LK7 to The posture adjustment mechanism 40 is configured so that the section center of LK9 coincides with the imaging center of the third imaging device M3, and further, the surface thereof coincides with the focal position (focus point) of the third imaging device M3. The posture of the holding unit 20 is controlled. As a result, the images of the upper surface of each of the sections LK7 to LK9 can be taken with high accuracy, so that a flaw or a foreign object can be accurately detected. In particular, since the posture of the lens L is individually controlled so that the perpendicular direction of the surface of each of the sections LK7 to LK9 is parallel to the imaging axis of the third imaging device M3, scratches or foreign matters obtained from the image data are controlled. The dimensional accuracy is increased, and it is possible to accurately perform the pass / fail determination.

  Fourth inspection area A4: As shown in FIG. 15, a fourth imaging device M4 is disposed below the fourth inspection area A4. A monochrome (for example, white) background plate P4 is disposed on the opposite side (that is, the upper side) of the fourth imaging device M4 with respect to the conveyed lens L. A fourth illumination device S4 is disposed below the fourth inspection region A4, and the lens L is irradiated with light suitable for inspection of scratches / foreign matter on the bottom surface.

  The fourth imaging device M4 detects a scratch or a foreign object on the lower surface of the lens L by photographing the lower surface of the lens L from below and analyzing the image. Specifically, here, the fourth imaging device M4 focuses on the surfaces of the fourth section LK4, the fifth section LK5, and the sixth section LK6, which are part of the lens L, and the respective surface states. Image. At this time, as shown in FIGS. 15B to 15D, the perpendicular direction of the center of each section of each section LK4 to LK6 is parallel to the inspection reference axis J, and each section LK4 to The posture adjustment mechanism 40 is arranged so that the section center of LK6 coincides with the imaging center of the fourth imaging device M4, and further, the surface thereof coincides with the focal position (focus point) of the fourth imaging device M4. The posture of the holding unit 20 is controlled. As a result, an image of the lower surface of each of the sections LK4 to LK6 can be taken with high accuracy, so that a flaw or a foreign object can be accurately detected. In particular, since the posture of the lens L is individually controlled so that the perpendicular direction of the surface of each of the sections LK4 to LK6 is parallel to the imaging axis of the fourth imaging device M4, scratches or foreign matters obtained from the image data are controlled. The dimensional accuracy is increased, and it is possible to accurately perform the pass / fail determination.

  Fifth inspection area A5: As shown in FIG. 16, the fifth imaging device M5 is disposed below the fifth inspection area A5. A monochrome (for example, white) background plate P5 is disposed on the opposite side of the fifth imaging device M5 with respect to the conveyed lens L. Further, a fifth illumination device S5 is disposed below the fifth inspection region A5, and the lens L is irradiated with light suitable for the inspection of the surface scratches and foreign matters.

  The fifth imaging device M5 detects a scratch or a foreign substance on the lower surface of the lens L by photographing the lower surface of the lens L from below and analyzing the image. Specifically, here, the fifth imaging device M5 focuses each surface of the first section LK1, the second section LK2, and the third section LK3, which are part of the lens L, and the respective surface states. Image. At this time, as shown in FIGS. 16 (B) to (D), the perpendicular direction of the partition center of each surface of each partition LK1 to LK3 is parallel to the inspection reference axis J, and each partition LK1 to LK1. The posture adjustment mechanism 40 is configured so that the section center of LK3 coincides with the imaging center of the fifth imaging device M5, and further, the surface thereof coincides with the focal position (focus point) of the fifth imaging device M5. The posture of the holding unit 20 is controlled. As a result, since the image of the upper surface of each of the sections LK1 to LK1 can be taken with high accuracy, it is possible to accurately detect a flaw or a foreign object. In particular, since the posture of the lens L is individually controlled so that the perpendicular direction of the surface of each of the sections LK1 to LK1 is parallel to the imaging axis of the fifth imaging device M5, scratches or foreign matters obtained from the image data are controlled. The dimensional accuracy is increased, and it is possible to accurately perform the pass / fail determination.

  Sixth inspection area A6: As shown in FIG. 17, a sixth imaging device M6 is disposed below the sixth inspection area A6. A monochrome (for example, white) background plate P6 is disposed on the opposite side of the sixth imaging device M6 with respect to the conveyed lens L. Further, a sixth illumination device S6 is disposed below the sixth inspection area A6, and the lens L is irradiated with light suitable for inspecting the surface for scratches and foreign matter.

  The sixth imaging device M6 detects a scratch or a foreign substance on the lower surface of the lens L by photographing the lower surface of the lens L from below and analyzing the image. Specifically, here, the sixth imaging device M6 focuses on the surfaces of the seventh section LK7, the eighth section LK8, and the ninth section LK9, which are part of the lens L, and the respective surface states. Image. At this time, as shown in FIGS. 17 (B) to (D), the perpendicular direction of the center of each section of each section LK7 to LK9 is parallel to the inspection reference axis J, and each section LK7 to The posture adjustment mechanism 40 is configured so that the section center of LK9 coincides with the imaging center of the sixth imaging device M6, and further, the surface thereof coincides with the focal position (focus point) of the sixth imaging device M6. The posture of the holding unit 20 is controlled. As a result, the images of the upper surface of each of the sections LK7 to LK9 can be taken with high accuracy, so that a flaw or a foreign object can be accurately detected. In particular, since the posture of the lens L is individually controlled so that the perpendicular direction of the surface of each of the sections LK7 to LK9 is parallel to the imaging axis of the sixth imaging device M6, scratches or foreign matters obtained from the image data are controlled. The dimensional accuracy is increased, and it is possible to accurately perform the pass / fail determination.

  Lens carry-out area OUT: As shown in FIG. 18, the imaging device MOUT is arranged above the lens carry-out area OUT. A monochrome (for example, black) background plate POUT is disposed on the opposite side of the imaging device MOUT with respect to the conveyed lens L. An illumination device SOUT is disposed above the lens carry-out area OUT, and the lens L is irradiated with light suitable for inspection of foreign matters such as bubbles inside the lens. As the color of the background plate POUT, a preferable color is selected for the bubble detection.

  The imaging device MOUT captures the inside of the lens L from above in multiple stages in the optical axis direction and analyzes the image to detect bubbles or the like inside the lens L. Specifically, here, as shown in FIGS. 18B to 18D, an upper imaging process in which the imaging device MOUT focuses on the upper vicinity LF1 inside the lens L, and the lens L A central imaging process in which the imaging device MOUT focuses on the inner vicinity LF2 in the optical axis direction and a lower imaging process in which the imaging device MOUT focuses on the lower vicinity LF3 in the lens L. And execute. That is, the posture adjustment mechanism 40 performs posture control so as to move the holding unit 20 in the optical axis direction, and performs the above-described imaging a plurality of times. As a result, since a multi-stage image can be taken with high accuracy in the depth direction inside the lens L, the internal bubbles can be detected accurately, and the pass / fail judgment of the bubbles can be performed accurately.

  Further, in the lens carry-out area OUT, the lens L that has been inspected is carried out by the lens carry-out device 79B. The lens carry-out device 79B sucks and carries the top or bottom surface of the lens L held by the posture adjustment unit 10 with the vacuum chuck BC.

  As described above, according to the lens inspection apparatus 1 of the present embodiment, the plurality of posture adjustment units 10 move together with the lens L from the lens supply area IN to the lens carry-out area OUT, and the inspection area A1 therebetween. In .about.A6, each posture adjustment unit 10 positions the lens L in a different posture, so that various inspections can be efficiently realized simultaneously and in parallel. In particular, since the route (inspection route) through which the lens L passes can be unified, it becomes possible to quickly identify the cause when a trouble occurs on the inspection route. As in the past, when a plurality of inspection units that are fixedly arranged are supplied with lenses L to perform various inspections individually, the path of the lens L branches to a plurality of inspection adjustment units. When trouble occurs in the inspection unit, it takes a long time to identify the cause.

  The lens inspection apparatus 1 has a plurality of inspection areas (lens carry-in area IN, first to sixth inspection areas A1 to A6, and lens carry-out area OUT). The partial surface is inspected concurrently. Thereby, since the inspection item and inspection area of each inspection area can be reduced, the inspection time of each inspection area can be shortened. As a result, inspection efficiency is greatly improved. In addition, since the holding posture of the lens L can be varied in each inspection region, it is possible to inspect with an optimum posture according to the uneven state of the surface of the lens L.

  Further, the lens inspection device 1 positions the posture of the lens L a plurality of times so that the optical axis directions are different from each other in each inspection region, and images the lens with the imaging device for each positioning. That is, various inspections can be performed even in a single inspection region. For example, even in a single inspection region, the focus center of the imaging device is positioned at various positions on the surface of the lens L a plurality of times, and further, tilt and / or focus control is performed, and then the lens L is imaged each time. As a result, the surface of the lens L can be divided into a plurality of sections, and a highly accurate inspection is realized.

  Further, in the lens inspection apparatus 1, during the inspection process (here, the lens supply region OUT), the lens L in the focus direction position (approach / separate direction position), XY adjustment (slide direction, that is, the optical axis center), Since the tilt adjustment (tilt direction, that is, the optical axis angle) is detected for each lens L, the inspection accuracy of each subsequent inspection region can be improved.

  Furthermore, in this lens inspection apparatus 1, the types of the imaging device (camera), the background plate, and the illumination device can be freely selected in each inspection region, and their arrangement can be set independently. That is, it is possible to independently construct an inspection environment that matches the inspection items of each inspection area. For example, in the first to third inspection areas A1 to A3, the imaging devices M1 to M3 are arranged above, and the background plates P1 to P3 are arranged below. On the other hand, in the fourth to sixth inspection areas A4 to A6, the imaging devices M4 to M6 are arranged below, and the background plates P4 to P6 are arranged above. The color and pattern of the background plate may be different for each inspection region.

  In this lens inspection apparatus 1, the transfer device 60 has a rotary table structure, and the posture adjustment units 10 modularized with the base 5 as a base are installed at equal intervals in the circumferential direction of the rotary table. . Therefore, in the manufacturing stage of the lens inspection apparatus 1, it is possible to perform an accuracy inspection and an operation test in units of the posture adjustment unit 10 in advance. Also, when setting up the lens inspection apparatus 1 at an assembly factory or the like, if the base 5 of the attitude adjustment unit 10 is fixed on the rotary table (adjusted), the installation work can be completed in a short time. Can be made. Even when the lens inspection device 1 breaks down, the maintenance becomes easy.

  In the present lens inspection apparatus 1, since the escape portions 25 </ b> A or gaps are formed in the arms 22 and 24 of the holding portion 20 that holds the lens L, interference with the convex portion LT of the lens L can be suppressed. As a result, the positioning accuracy of the lens L by the posture adjustment mechanism 40 can be increased.

  In the lens inspection apparatus 1 described above, the surface area of the lens L is divided by the first to sixth inspection areas A1 to A6, and the inspection is performed while being dispersed in each inspection area. It is not limited to this. For example, the depth direction (optical axis direction) in the lens L may be divided and inspected while being dispersed in each inspection region. That is, the bubble inspection inside the lens L may be dispersed in a plurality of inspection areas.

  Moreover, in the said lens inspection apparatus 1, although the case where a contour shape, a crack | wound of a surface, a foreign material, an internal bubble etc. was test | inspected was illustrated, an inspection item is not limited above. For example, in the case of a film forming lens, the unevenness of film formation and the film thickness can be inspected, and the uneven shape of the lens can be inspected by irradiating a laser displacement meter.

  Furthermore, in the lens supply area IN of the lens inspection device 1, the case where the optical axis center of the lens L and the angle thereof are detected by using the optical axis adjustment device (chart device) W is exemplified. It is not limited. For example, a laser displacement meter (height measuring instrument) or the like is placed in the lens supply area IN, the position of the lens center and / or its height (focus direction position) is detected, and the information is used. At the downstream process, posture control may be performed to perform lens inspection.

  Furthermore, it is preferable that the X tilt mechanism (rotation mechanism) 40XT of the attitude adjustment mechanism 40 can rotate 180 ° or more. In this way, by inverting the front and back of the lens L in a specific inspection region, both surfaces can be inspected with a common imaging device.

  Furthermore, in the lens inspection apparatus 1, the case where the inspection is performed by the plurality of posture adjustment units 10 is illustrated, but the present invention is not limited to this. For example, as shown in FIG. 19, the lens inspection apparatus 1 is fixedly provided with the posture adjustment unit 10, and the lens L is supplied to the holding unit 20 of the posture adjustment unit 10 manually or by a robot. The lens L may be inspected by the imaging device while changing the posture of the lens L. Even in such a case, since the lens L can be inspected in various postures by the posture adjustment mechanism 40 of the posture adjustment unit 10, the inspection accuracy can be increased.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Lens inspection apparatus 5 Base 10 Posture adjustment unit 20 Holding part 22 First arm 24 Second arm 26 Arm moving part 40 Posture adjustment mechanism 40XS Shift mechanism 40XT Tilt mechanism 40YS Shift mechanism 40YT Tilt mechanism 40ZS Shift mechanism 40ZT Tilt mechanism 60 Transfer Device BC Vacuum chuck L Lens

Claims (4)

A lens inspection device for inspecting a lens,
A plurality of posture adjustment units;
A lens supply device for supplying the lens to the posture adjustment unit in a lens supply region;
A lens unloading device for unloading the lens from the posture adjustment unit in a lens unloading region;
A transfer device for moving the plurality of posture adjustment units so as to pass through the lens supply area and the lens carry-out area;
A plurality of inspection regions existing while the posture adjustment unit is moved from the lens supply region to the lens unloading region;
An imaging device that is disposed in each of the plurality of inspection regions and images the lens;
With
Each of the posture adjustment units has a holding portion that holds the periphery of the lens, and a posture adjustment mechanism that adjusts the posture of the holding portion,
The posture adjustment mechanism is
An X shift mechanism for moving the holding portion in the X direction on the XY plane;
A Y shift mechanism for moving the holding portion in the Y direction on the XY plane;
An X tilt mechanism for tilting or rotating the holding portion around the X axis;
A Y tilt mechanism for tilting or rotating the holding portion around the Y axis,
The posture adjustment unit performs posture control of the lens by the posture adjustment mechanism in each of the plurality of inspection regions ;
The plurality of imaging devices arranged in the plurality of inspection regions focus on different sections of the lens and perform imaging.
The posture adjusting mechanism performs tilt control around the X axis and around the Y axis in units of the sections, and performs movement control of the XY plane in units of the sections .
Lens inspection device. A lens inspection device for inspecting a lens,
A plurality of posture adjustment units;
A lens supply device for supplying the lens to the posture adjustment unit in a lens supply region;
A lens unloading device for unloading the lens from the posture adjustment unit in a lens unloading region;
A transfer device for moving the plurality of posture adjustment units so as to pass through the lens supply area and the lens carry-out area;
A plurality of inspection regions existing while the posture adjustment unit is moved from the lens supply region to the lens unloading region;
An imaging device that is disposed in each of the plurality of inspection regions and images the lens;
With
Each of the posture adjustment units has a holding portion that holds the periphery of the lens, and a posture adjustment mechanism that adjusts the posture of the holding portion,
The posture adjustment mechanism is
An X shift mechanism for moving the holding portion in the X direction on the XY plane;
A Y shift mechanism for moving the holding portion in the Y direction on the XY plane;
An X tilt mechanism for tilting or rotating the holding portion around the X axis;
A Y tilt mechanism for tilting or rotating the holding portion around the Y axis,
The posture adjustment unit performs posture control of the lens by the posture adjustment mechanism in each of the plurality of inspection regions ;
The imaging device in the specific inspection region focuses on a plurality of different sections in the lens and images each,
The posture adjustment mechanism performs tilt control around the X axis and the Y axis with the section as a unit for each imaging of the section with the imaging device, and on the XY plane with the section as a unit. It is characterized by performing movement control .
Lens inspection device. In each of the plurality of inspection regions, a background plate is disposed on the side opposite to the imaging surface of the lens,
Lens inspection system according to claim 1 or 2. A lighting device is disposed in each of the plurality of inspection regions,
Lens inspection apparatus according to any one of claims 1 to 3.

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