JP2006329714A - Lens inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To economically and effectively inspect the definition of a lens, or defects such as presence of a flaw or foreign matter. <P>SOLUTION: The lens inspection apparatus is constituted such that the lens W to be inspected is taken out from the transfer tray 16 with a lens transfer mechanism, and after confirming the attitude of the lens with a lens attitude observation camera 17, delivered to the first adjustment stage 22. The first adjustment stage 22 is made moveable in X direction, and the chart 27 for inspecting the foreign matter and flaw and the chart 29 for inspecting the definition of the lens, and an illumination device are arranged thereon. The inspection of the lens is performed by using these charts 27 and 29, and if determined unacceptable, the defective lens is collected in the recovery tray 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens inspection apparatus that inspects a lens.

  Optical parts such as a photographic lens and a finder lens used in a camera are deteriorated in optical performance if the surface is scratched or air bubbles are contained in the lens during the manufacturing process. Further, if foreign matters such as dust and dirt are attached to the optical component, the optical performance is remarkably deteriorated. For this reason, it is necessary to reliably detect the presence of scratches and foreign matters and to remove such optical components at the manufacturing stage.

Here, as an apparatus for inspecting a lens, a lens inspection apparatus using a projector is known (for example, see Patent Document 1). An outline of a lens inspection apparatus as disclosed in Patent Document 1 will be described with reference to FIG. The lens 104 to be tested that has undergone the cleaning / blowing process is carried on the pallet 102. In a state where the test lens 104 is placed on the pallet 102, the test lens 104 is illuminated by an LED (light emitting diode) 101 provided in a projector 103 fixed to the apparatus main body (not shown). The light passing through 104 is photographed by the imaging apparatus 100, and the photographed image is subjected to image processing by a personal computer (not shown). As a result of the determination, the lens 104 to be tested, which is determined as having no foreign matter attached thereto, is conveyed to another apparatus such as a focus inspection.
JP 2002-90258 A

However, in the lens inspection apparatus as shown in FIG. 8, when the test lens 104 is supplied to the through hole of the pallet 102, the test lens 104 gets on the peripheral part of the through hole even slightly, or the placement position is shifted. In this case, since the illumination light from the LED 101 does not enter the imaging device 100 correctly, it is difficult to check foreign matter and scratches, and the test lens cannot be inspected with high accuracy.
In addition, since foreign objects and scratches are inspected before focus adjustment is performed, it is difficult to accurately perform evaluation at the imaging position of the lens 104 to be measured, which is important in determining the image quality.

Furthermore, since the focus is inspected by another focus inspection device after the foreign matter and scratch inspection, the cost and installation space for two devices are required. Furthermore, in order to inspect with the focus inspection apparatus, it is necessary to replace the lens 104 to be tested with another pallet for the focus inspection apparatus, or to change the setup, which increases the number of steps.
Since the measurement is performed with the pallet 102 moving in the horizontal direction on the transport line, the posture of the lens 104 to be tested is fixed, and foreign matter or scratches are applied to the entire area of the lens 104 to be tested. The inspection could not be performed.
The present invention has been made in view of such circumstances, and has as its main object to inexpensively and effectively detect whether there is a focus inspection and a flaw or a defect of foreign matter.

The invention according to claim 1 of the present invention for solving the above-described problems includes a lens holding means for sucking and holding a test lens, a posture control means for correcting the posture of the test lens held by the lens holding means, Image processing means for capturing an image obtained through the test lens after posture correction, focus position detection means for detecting a focus position of the test lens in cooperation with the image processing means, and the image processing means The lens inspection apparatus includes a foreign matter and a flaw detection means for detecting a foreign matter and a flaw of the lens to be examined by cooperating with the lens.
In this lens inspection apparatus, with the lens holding means held by the lens holding means, the posture control means is used to correct the test lens to a posture suitable for inspection. After the posture correction, the focus position detection means is used and an image obtained through the lens to be examined is acquired by the image processing means. For example, the contrast of the image is calculated, and the position where the contrast value is maximized is recognized as the focus coupling position. Further, an image obtained through the lens to be examined is acquired by the image processing means using the foreign matter and scratch detection means. For example, when the difference in the light intensity distribution of the image is equal to or greater than a set threshold value, it is considered that a foreign object or a scratch exists.

According to a second aspect of the present invention, in the lens inspection apparatus according to the first aspect of the present invention, the inspection inspection stage includes an inspection transfer stage that is movable in a uniaxial direction. An adjustment stage for holding a lens and the image processing means are provided, and the adjustment stage is configured to be able to adjust a distance in the optical axis direction between the image processing means and the lens to be examined. It is characterized by that.
In this lens inspection apparatus, the distance between the image processing means and the lens to be examined is changed on the adjustment stage when the inspection is performed using the focus position detection means or the foreign matter / scratch detection means. In the focus position inspection, the position where the contrast value is maximized is found by moving the lens to be tested along the optical axis on the adjustment stage. In the inspection of foreign matter and scratches, for example, the difference in light intensity distribution obtained by the image processing means is calculated at the front focus position, the rear focus position, and the just focus position, respectively, and this difference exceeds a set threshold value. Sometimes considered as foreign or scratched.

According to a third aspect of the present invention, in the lens inspection apparatus according to the second aspect, the inspection transfer stage includes the focus position detection unit and the focus position detection unit from a transfer position where the adjustment stage is arranged side by side with the posture control unit. The adjustment stage is movably arranged in order to each inspection position where each of the foreign matter and flaw detection means and the optical axis of the lens to be inspected coincide with each other.
In this lens inspection apparatus, the lens to be inspected after posture correction is quickly received, and the inspection by the focus position detection means and the inspection by the foreign matter and scratch detection means are sequentially performed.

According to a fourth aspect of the present invention, in the lens inspection apparatus according to the second aspect, a plurality of the inspection transport stages are laid in parallel, and the focus position detection means, the foreign matter and the flaw detection means are the adjustments. It is configured to be movable in a direction orthogonal to the moving direction of the stage.
In this lens inspection apparatus, the inspection by the focus position detection means and the inspection by the foreign matter and scratch detection means are performed at each of the inspection transfer stages arranged in parallel. For example, when the test lens on the first inspection transport stage is inspected by the focus position detecting means, foreign matter and scratches are detected on the other test lenses on the second inspection transport stage. Inspection by means can be performed.

According to a fifth aspect of the present invention, in the lens inspection apparatus according to the third or fourth aspect, the posture control means includes an imaging means for observing the posture of the lens to be examined, and the imaging means The arrangement direction of the imaging unit and the tray and the moving direction of the stage portion of the inspection transport stage are orthogonal to each other.
In this lens inspection apparatus, the test lens is taken out from the tray and subjected to posture correction, and then the test lens is delivered to the adjustment stage on the first inspection transport stage. While the adjustment stage on the first inspection transport stage is moved to the inspection position, another lens is transferred to the adjustment stage on the second inspection transport stage. Since the movement path of the lens to be examined from the tray to the adjustment stage is orthogonal to the movement path at the time of inspection, the two movement paths hardly interfere with each other.

According to the present invention, by using the posture control means, it becomes possible to correct the posture of the test lens to the designed measurement position before carrying out the inspection, so when inspecting the test lens. Therefore, it is possible to prevent the displacement of the test lens. Therefore, it is possible to accurately detect the focus position and inspect for the presence or absence of foreign matter or scratches.
In addition, since it is possible to inspect foreign matter and scratches after detecting the focus position, foreign matter and scratches can be evaluated at the focus connection position, which is the most important for image quality evaluation.
Since focus inspection, foreign matter and scratch inspection can be performed by one apparatus, the installation space is about ½ compared to the case where two apparatuses are separately installed. Further, the number of components shared by the conventional apparatus for inspecting foreign matter and scratches and the apparatus for inspecting the focus position can be reduced to one. Furthermore, as in the prior art, it is not necessary to transfer the lens to be inspected or to change the setup in order to inspect with a device for inspecting the focus position from a device for inspecting foreign matter and scratches, and the work man-hours can be reduced. Can be reduced.
If the distance in the optical axis direction between the test lens and the image processing means can be adjusted, the test lens can be divided and evaluated in the axial direction. It is possible to inspect all the areas for the presence of foreign matter and scratches. Therefore, the optical performance of the lens to be examined can be evaluated with higher accuracy.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing an outline of the entire lens inspection apparatus, and FIG. 2 is a side view. 3 and 4 show detection charts, and FIG. 5 shows the configuration of the adjustment stage.

  As shown in FIG. 1, the lens inspection apparatus 1 is provided with a lens transport mechanism 3 on an apparatus body 2. The lens transport mechanism 3 has a lens transport Y-direction stage 10 fixed to the apparatus main body 2 by screws. The lens transport Y direction stage 10 has a rail portion 10A laid in the horizontal Y direction and a slide portion 10B movable on the rail portion 10A. The lens transport X direction stage 11 is on the slide portion 10B. Is fixed with screws. The lens transport X-direction stage 11 has a rail portion 11A extending in the X direction, which is a horizontal direction orthogonal to the Y direction, and a slide portion 11B movable on the rail portion 11A, and the lens transport is on the slide portion 11B. The Z direction stage 12 is screw-fixed. The lens transport Z direction stage 12 includes a rail portion 12A extending in a height direction (Z direction) perpendicular to the XY direction, and a slide portion 12B movable with respect to the rail portion 12A. The conveyance θ direction stage 13 is fixed with screws. The lens transport θ-direction stage 13 is configured to be rotatable in the θ direction around the Z axis, and a holding portion 14 is provided as a lens holding means for sucking and holding the lens W to be tested at the lower end thereof. The holding unit 14 is connected to a suction device (not shown).

Within the movement range of the lens transport mechanism 3, a lens transport tray 16, a lens posture observation camera 17, and a defective lens collection tray 18 are arranged in this order along the Y direction.
The lens transport tray 16 and the defective lens collection tray 18 have the same shape. Specifically, a concave recess is formed so that the convex shape of the test lens W can be accommodated, and the test lens W can be placed in four rows and three columns. The lens transport tray 16 and the defective lens collection tray 18 may be carried in and out by a robot (not shown), or an operator may set the test lens W manually.
The lens orientation observation camera 17 has an imaging surface set upward, and an annular light source 19 is attached to an upper end portion thereof.

  Further, the apparatus main body 2 is provided with a first inspection transport stage 20 so as to be aligned with the lens posture observation camera 17 in the X direction. Further, a second inspection transport stage 21 is disposed in parallel to the first inspection transport stage 20 on the defective lens collection tray 18 side of the first inspection transport stage 20. At least a part of the inspection transport stages 20 and 21 is disposed within the movement range of the lens transport mechanism 3. The number of inspection transfer stages 20 and 21 may be one or three or more.

  In the first inspection transport stage 20, a guide part 20A fixed to the apparatus main body 2 by screws is extended in parallel with the X direction, and a slide part 20B is provided on the guide part 20A so as to be movable in the X direction. A first adjustment stage 22 is fixed on the slide portion 20B. Similarly, the second inspection transport stage 21 has a guide portion 21A extending in parallel to the X direction and a slide portion 21B movable on the guide portion 21A. The second adjustment stage 23 is placed on the slide portion 21B. Is fixed.

  Further, a chart transport stage 24 and a chart transport stage 25 are arranged in parallel to the Y direction from the lens transport mechanism 3 side above the first and second inspection transport stages 20 and 21. . The chart transport stage 24 includes a rail portion 24A fixed to the apparatus main body 2 and a slide portion 24B that is movable in the Y direction while being suspended from the rail portion 24A. The slide portion 24B includes an illumination device 26. The foreign matter and scratch detection chart 27 are attached in order from the top. The chart transport stage 25 has a rail portion 25A fixed to the apparatus main body 2 and a slide portion 25B that is movable in the Y direction while being suspended from the rail portion 25A. The slide portion 25B is illuminated. The device 28 and the focus detection chart 29 are attached in order from the top. As illustrated in FIG. 3, the foreign object and scratch detection chart 27 is plain and milky white. As shown in FIG. 4, the focus detection chart 29 is composed of patterns having different pitches in the vertical direction and the horizontal direction.

  Next, details of the configuration of the first adjustment stage 22 will be described with reference to FIGS. 2 and 5 to 7. Since the first adjustment stage 22 and the second adjustment stage 23 have the same configuration, only the first adjustment stage 22 will be described below.

  As shown in FIG. 2, the first adjustment stage 22 has a base plate 30 that is screwed to the upper portion of the slide portion 20 </ b> B, and an adjustment X-direction stage 31 that can move in the X direction is placed on the base plate 30. It is fixed with a screw (not shown). As shown in FIG. 5, an adjustment Y direction stage 32 that is movable in the Y direction with respect to the adjustment X direction stage 31 is fixed on the adjustment X direction stage 31 with a screw (not shown). Further, an adjustment Z direction stage 33 that is movable in the Z direction is fixed to the adjustment Y direction stage 32 with a screw (not shown). A pair of chucks 34 extend in parallel to the Y direction from a slide portion 33A that is movable in the Z direction on the adjustment Z direction stage 33. These chucks 34 are supported so as to be movable in the X direction. A taper 34 </ b> A is formed on the inner side surface of each chuck 34 so as to open upward. The taper 34A is set to an angle that does not block the light beam passing through the inspection target area of the lens W to be inspected when performing a focus position inspection or the like. The chucks 34 are connected to an air actuator built in the slide portion 33A, and the chucks 34 can be brought close to or separated from each other in the X direction.

Further, on the base plate 30, a temporary receiving table 35 on which the test lens W is temporarily mounted when the lens W is transferred from the lens transport tray 16 to the first adjustment stage 22 is fixed with a screw (not shown). As shown in FIG. 2, a concave portion 36 is formed on the upper portion of the temporary support base 35. The shape of the recess 36 is recessed so that the convex shape of the lens W to be tested can be accommodated. The shape of the recess 36 is not limited to the shape shown in FIG. 2 as long as the lens W can be positioned and placed. The central portion of the recess 36 is connected to a cavity 37, and the cavity 37 is connected to a vacuum pump (not shown). The height of the upper surface of the temporary support 35 is substantially equal to the height of the upper surfaces of the trays 16 and 18 and is higher than the upper surface of the light source 19 above the lens posture observation camera 17.
Further, on the upper surface of the base plate 30, a CCD (Charge Coupled Devices) 38 as an image processing means is disposed within the movable range of the adjustment X direction stage 31, the adjustment Y direction stage 32 and the adjustment Z direction stage 33. Yes. The CCD 38 is positioned and fixed so as to be replaceable by four fixing pins 39 attached to the base plate 30. The same CCD 38 may always be used, or may be exchanged according to the lens W to be examined. When the CCD 38 is exchanged, the position is adjusted with the fixing pin 39.

  As shown in FIG. 1, the lens inspection device 1 includes a control device 50 and an operation unit 51 including a button that receives an operation of the operator. The control device 50 is equipped with a CPU (Central Processing Unit), a memory, and the like, and controls the entire device. The control device 50 may be a personal computer.

  As will be described in detail later, the posture control means in this embodiment includes a lens transport mechanism 3, a lens posture observation camera 17, a light source 19, and a control device 50. The foreign matter / scratch detection means includes a chart transport stage 24, an illumination device 26, a foreign matter / scratch detection chart 27, and a control device 50. The focus position detection means includes a chart transport stage 25, an illumination device 28, a focus detection chart 29, and a control device 50.

Next, the operation of this embodiment will be described.
The lens transport tray 16 on which the test lens W is mounted is placed at a predetermined position, and an inspection start button of the operation unit 51 is pressed. The lens transport Y-direction stage 10 and the lens transport X-direction stage 11 of the lens transport mechanism 3 are driven, and the lower surface of the holding unit 14 moves so as to coincide with the position of the first horizontal row and the first vertical column of the lens transport tray 16. To do. Thereafter, the lens conveyance Z-direction stage 12 is lowered, and the holding portion 14 at the lower end of the lens conveyance θ-direction stage 13 is brought into contact with the lens W to be examined. When the holding lens 14 is sucked and held by the holding unit 14, the lens transport mechanism 3 is driven to move the test lens W above the lens posture observation camera 17.

  The light source 19 attached to the tip of the lens posture observation camera 17 is turned on, and the lens posture observation camera 17 performs imaging while illuminating the lens W to be examined. The control device 50 calculates the posture of the lens W currently being held from the image acquired by the lens posture observation camera 17 by image processing, and the lens W to perform measurement. Judge whether it was held in an appropriate posture. For example, when the actual posture of the lens W is shifted in the θ direction compared to the design position stored in advance in the control device 50, or when the position shift occurs in the XY direction. If the state is not appropriate, the lens transport X-direction stage 11, the lens transport Y-direction stage 10, the lens transport Z-direction stage 12 and the lens transport X-direction stage 11, so that the displacement in the XYθ direction is zero. Each axis of the lens conveyance θ direction stage 13 is driven to correct the lens W to be in a posture suitable for inspection. During this time, the first inspection transport stage 20 moves the first adjustment stage 22 to a position where the lens W to be tested can be supplied (delivery position) as shown in FIG. Similarly, the second inspection transport stage 21 moves the second adjustment stage 23 to a delivery position where the test lens W can be supplied.

  When it is confirmed by image processing that the posture of the test lens W has been corrected by the lens posture observation camera 17, the test lens W is horizontally moved in the X direction. At this position, the temporary support 35 of the first adjustment stage 22 of the first inspection transport stage 20 is waiting, so the lens transport Z-direction stage 12 is slightly lowered and the lens W to be tested is placed in the recess 36. Put. After placing the test lens W, suction holding by the concave portion 36 is started, while suction of the holding portion 14 is released, and then the lens transport Z-direction stage 12 is raised, and the lens transport mechanism 3 is moved to the first adjustment stage 22. Evacuate from around. By transferring the test lens W to the first adjustment stage 22 in this way, the positional deviation of the test lens W is prevented.

  The first adjustment stage 22 drives the adjustment X-direction stage 31 and the adjustment Y-direction stage 32 to move the chuck 34 above the lens W to be tested of the temporary support 35 and then lowers the adjustment Z-direction stage 33. Let The chuck 34 connected to the air actuator is moved in the approaching direction, and both ends of the lens W to be tested placed on the temporary support table 35 are sandwiched. After the suction by the concave portion 36 is released, the adjustment Z direction stage 33 is slightly raised. As a result, as shown in FIG. 6, the outer peripheral edge of the lens W to be tested is held while the posture of the lens W is corrected.

  Next, as shown in FIG. 7, the adjustment X direction stage 31 and the adjustment Y direction stage 32 are moved so that the axis (optical axis) S <b> 1 of the lens W to be tested and the center position of the CCD 38 coincide with each other. At this time, the adjustment Z direction stage 33 is moved to a position deviated upward from the designed focus position. This operation is performed while moving the slide portion 20B on which the first adjustment stage 22 is mounted in the X direction, so that the lens W to be tested passes below the foreign object and scratch detection chart 27 and directly below the focus detection chart 29. When the inspection position is reached, the slide portion 20B is stopped. The focus detection chart 29 is illuminated downward by the illumination device 28, and an image of the focus detection chart 29 that forms an image through the lens W is acquired by the CCD 38. The image of the focus detection chart 29 is acquired while moving the lens W to be detected downward, and the control device 50 calculates the contrast of the chart image based on the output signal from the CCD 38, and the focus is determined based on the result. Detect position.

  When the detection of the focus position is completed, the slide unit 20B is moved back in the X direction, and the first adjustment stage 22 is moved to an inspection position corresponding to a position directly below the foreign object and scratch detection chart 27. During this time, the adjustment Z direction stage 33 receives a command from the control device 50 and moves the test lens W to the position where the focus is detected. The illumination device 26 illuminates the foreign matter and scratch detection chart 27 downward, and the CCD 38 acquires an image of the foreign matter and scratch detection chart 27 that forms an image through the lens W to be examined. The output of the CCD 38 is sent to the control device 50. After the image is divided into, for example, 10 × 20 rectangles by image processing, the average luminance is obtained for each rectangle. When the difference between the luminance levels of the rectangles adjacent to each other exceeds a predetermined threshold value, it is determined that there is a foreign object or a scratch in this portion, and the lens W to be tested is determined as a defective product. On the other hand, if the difference in luminance level is within a certain threshold value, the lens W to be tested is determined as non-defective.

  If no foreign object or scratch is found at the focus detection position, the same inspection is performed for 0.15 μm in the front pin direction and 0.15 μm in the rear pin direction based on the focus position. As a result, it is possible to detect foreign matter and scratches that are imaged on the CCD 38 while the focus is shifted. Although the amount of movement from the focus position is 0.15 μm before and after, the amount of movement of the front pin can be set arbitrarily, and the number of measurement points is also 0.15 μm, 0.3 μm on the front pin side, and on the rear pin side Any number such as 0.15 μm and 0.3 μm can be set. In this way, by performing the inspection at the focus position and the position shifted from the focus position in the direction of the axis S1, foreign matter and scratches can be detected for the entire region in the lens W to be tested.

  When the inspection for the presence or absence of foreign matter or scratches is completed, the adjustment stage 22 is returned to the delivery position while returning the lens W to be temporarily returned to the temporary support 35. If the test lens W is received by the holding unit 14 of the lens transport mechanism 3 and the test lens W is determined to be a non-defective product by the control device 50, it is returned to the original position of the lens transport tray 16. On the other hand, in the case where the lens W is determined to be a defective product by the control device 50, it is transported to the defective lens collection tray 18 and placed at a predetermined position on the defective lens collection tray 18. Since the position of the lens W to be inspected that has been inspected is managed on the control device 50 side, the above-described processing until all the uninspected lens W to be inspected is repeated thereafter.

  Here, in this embodiment, since there are two inspection transport stages 20 and 21, the foreign object and scratch detection chart 27 is used for the first lens W in the first inspection transport stage 20. During the inspection, the second inspection conveyance stage 21 can inspect the second lens W to be inspected using the focus detection chart 29. In addition, the inspection can be performed with the reverse combination. In this case, the chart transport stages 24 and 25 move the foreign object / scratch detection chart 27, the focus detection chart 29, and the corresponding illumination devices 28 and 29 in the Y direction, as shown by phantom lines in FIG. Are alternately arranged on either one of the adjustment stages 22 and 23. Further, since the adjustment stages 22 and 23 and the lens transport mechanism 3 are configured so as not to interfere with each other, other stages and the like are not obstructed while the lens W is being transported or during the inspection.

According to this embodiment, since the posture of the test lens W is confirmed by the lens posture observation camera 17 before the focus position is detected, the provisional lens W is temporarily corrected in the corrected state. The test lens W can be set on the cradle 35. Accordingly, since the displacement of the lens W to be detected is prevented, it is possible to accurately detect the focus position and the foreign matter.
Since the chuck 34 is provided with the taper 34 </ b> A, it is possible to detect the focus position and the detection of a foreign substance or the like with respect to all the inspection target areas in the lens W to be tested.
Since the foreign object and scratch detection chart 27 and the focus detection chart 29 are arranged in the movement path of the adjustment stages 22 and 23, the detection of the focus position and the detection of the foreign object and the like can be sequentially performed with one apparatus. Therefore, it is not necessary to transfer the lens W to be tested between these inspections, so that it is possible to prevent the positional shift between them and to shorten the time required for detection. Further, the installation cost can be reduced by reducing the installation area and sharing the components.

The heights of the trays 16 and 18 and the temporary support base 35 are substantially equal, and these heights are close to the height of the lens W to be detected when the posture of the lens W to be detected using the lens posture observation camera 17 is detected. Thus, the vertical movement of the lens transport mechanism 3 can be minimized. Therefore, the inspection time can be shortened.
Since the two inspection transfer stages 20 and 21 are provided, it becomes possible to inspect the two test lenses W separately, and when a large number of the test lenses W are inspected, the inspection time as a whole is shortened. be able to. Here, since the both trays 16 and 18, the arrangement direction of the lens posture observation camera 17 and the movement direction of the adjustment stages 22 and 23 are arranged to be orthogonal to each other, the plurality of test lenses W can be smoothly and It can be moved efficiently. In addition, since the foreign object / scratch detection chart 27 and the focus detection chart 29 and the corresponding illumination devices 26 and 28 are configured to be movable in the Y direction, the inspection transport stages 20 and 21 due to variations in the illumination devices 26 and 28 are configured. An error can be prevented. Furthermore, since the illumination devices 26 and 28 are small, the device cost can be reduced, and the replacement of the lamp for the light source is facilitated.

Note that the present invention can be widely applied without being limited to the above-described embodiment.
For example, although the lens transport tray 16 is arranged in four rows and three columns, the number of test lenses W placed on the lens transport tray 16 can be increased according to the size of the test lens W. Further, in order to obtain the average luminance, the vertical and horizontal rectangular divisions are set to 10 × 20. However, the division number can be arbitrarily set depending on the size of the foreign matter to be extracted and the scratches.
Further, the adjustment stages 22 and 23 may change the CCD 38 according to the lens W to be examined. On the other hand, the CCD 38 may be fixed to the base plate 30 in advance.
One foreign substance / scratch detection chart 27 and one focus detection chart 29 may be provided for each inspection transport stage 20, 21. Further, the arrangement in the X direction with the foreign object / scratch detection chart 27 and the focus detection chart 29 may be reversed.
The lens transport tray 16, the lens orientation observation camera 17, the delivery position of the adjustment stages 22 and 23, and the defective lens collection tray 18 may be arranged in this order in the X direction.

It is a top view which shows schematic structure of the lens inspection apparatus which concerns on embodiment of this invention. It is a side view which shows schematic structure of a lens test | inspection apparatus. It is a figure which shows the chart for a foreign material and a flaw detection. It is a figure which shows the chart for focus detection. It is a perspective view which shows the structure of an adjustment stage. It is a figure explaining the operation | movement which hold | maintains a to-be-tested lens. It is a figure explaining the test | inspection of a foreign material, a damage | wound, and a focus. It is a figure explaining the outline of the conventional lens inspection apparatus.

Explanation of symbols

1 Lens inspection device 3 Lens transport mechanism (attitude control means)
14 Holding part (Lens holding means)
17 Lens posture observation camera (posture control means)
19 Light source (attitude control means)
20 First inspection transport stage 20B, 21B Slide portion 21 Second inspection transport stage 22 First adjustment stage 23 Second adjustment stage 24 Chart transport stage (foreign matter and flaw detection means)
25 Chart transport stage (focus position detection means)
26 Illumination device (foreign matter and flaw detection means)
27 Foreign matter and scratch detection chart (foreign matter and scratch detection means)
28 Illumination device (focus position detection means)
29 Focus detection chart (Focus position detection means)
38 CCD (image processing means)
W Test lens

Claims (5)

  Image processing for picking up an image obtained through a lens holding means for sucking and holding the test lens, a posture control means for correcting the posture of the test lens held by the lens holding means, and the post-correction lens And a focus position detecting means for detecting the focus position of the lens to be tested by cooperating with the image processing means, and detecting foreign matter and scratches on the lens to be tested by cooperating with the image processing means. A lens inspection apparatus comprising a foreign object and a flaw detection means.   An inspection transport stage that is movable in a uniaxial direction is provided, and an adjustment stage that holds the test lens is provided on a movable slide portion of the inspection transport stage, and the image processing means is provided. The lens inspection apparatus according to claim 1, wherein the adjustment stage is configured to be able to adjust a distance in an optical axis direction between the image processing unit and the lens to be examined.   In the inspection transport stage, the optical axis of the lens to be inspected coincides with each of the focus position detection unit, the foreign matter and the flaw detection unit, from a transfer position where the adjustment stage is arranged side by side with the posture control unit. The lens inspection apparatus according to claim 2, wherein the adjustment stage is movably arranged in order to each inspection position.   A plurality of the inspection transfer stages are laid in parallel, and the focus position detection means, the foreign matter and the flaw detection means are configured to be movable in a direction orthogonal to the movement direction of the adjustment stage. The lens inspection device according to claim 2. The posture control means includes an image pickup means for observing the posture of the test lens, and the image pickup means is arranged side by side with a tray on which the test lenses are arranged. The image pickup means and the tray 5. The lens inspection apparatus according to claim 3, wherein the arrangement direction is orthogonal to a moving direction of the stage portion of the inspection transport stage.

Images