CN111521617A - Optical detection apparatus, control method of optical detection apparatus, and storage medium - Google Patents
Optical detection apparatus, control method of optical detection apparatus, and storage medium Download PDFInfo
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Abstract
The embodiment of the invention discloses an optical detection device, a control method of the optical detection device and a storage medium, wherein the optical detection device comprises: the controller is used for controlling the defocusing measuring unit to collect defocusing amounts at least two different detection positions on the surface of the inspection product; when the motion platform is controlled to drive the at least two different detection positions of the inspection product to reach the lower part of the camera unit, the height adjustment of the motion platform is completed according to the defocusing amount of the at least two different detection positions, and the camera unit is controlled to acquire images of the at least two different detection positions; and controlling the image processing device to finish the focal depth correction of the images at the at least two different detection positions and the defect identification of the images after the focal depth correction according to the corresponding defocusing amount at the at least two different detection positions and the height adjustment value of the motion platform. The problem of current optical detection equipment exist the defect identification rate of accuracy of inspection product lower is solved.
Description
Technical Field
The embodiment of the invention relates to the field of optical detection, in particular to optical detection equipment, a control method of the optical detection equipment and a storage medium.
Background
Automatic Optical Inspection (AOI) equipment can realize rapid, high-precision and nondestructive Inspection of wafers, chips or other objects to be inspected, and is widely applied to multiple fields such as PCBs (Printed Circuit boards), IC chips (Integrated Circuit chips), LEDs (Light emitting diodes), TFTs (Thin Film transistors, TFTs), and solar panels. In the manufacturing industry of liquid crystal panels such as TFT, etc., because of the large size of the substrate, in order to guarantee the detection speed of the optical detection equipment, a multi-head camera unit is required to detect simultaneously. Simultaneously along with the continuous promotion of panel trade to defect detection accuracy requirement, also more and more strict to camera unit's formation of image resolution ratio, camera unit formation of image depth of focus also is littleer and more.
Because the optical detection equipment has out of focus problem when detecting the defect for the image quality that the camera unit gathered is lower, thereby leads to the defect discernment rate of accuracy to be lower, the condition of erroneous judgement of a large amount of inspection objects appears even. To solve this problem, the focus adjustment accuracy and the adjustment speed of the lens of the camera unit are mainly improved. However, as the focal depth of the detection lens is gradually reduced, the requirement on the adjustment precision of the focusing surface is higher and higher, which greatly increases the manufacturing cost of the optical detection equipment, and the defect identification accuracy of the inspection product is not obviously improved.
In conclusion, the existing optical detection equipment has the problem that the defect identification accuracy rate of the inspection product cannot meet the requirements of users.
Disclosure of Invention
The embodiment of the invention provides optical detection equipment, a control method of the optical detection equipment and a storage medium, and solves the problem that the defect identification accuracy of a detected product of the existing optical detection equipment cannot meet the requirements of users.
In a first aspect, an embodiment of the present invention provides an optical detection apparatus, including:
the motion platform is used for driving the inspection product to move along a first direction;
the defocusing measuring unit is arranged right above the moving table and used for collecting defocusing amount at least two different detection positions on the surface of the inspection object, wherein the at least two different detection positions are distributed along a second direction, and the first direction is vertical to the second direction;
the camera shooting unit is arranged right above the motion table and used for collecting images at the at least two different detection positions, wherein the at least two different detection positions are positioned in the same image;
image processing means for performing focus depth correction of the images at the at least two different detection positions and defect identification of the focus depth-corrected images;
the controller is used for controlling the defocusing measuring unit to acquire defocusing amounts at least two different detection positions of the surface of the inspection object; and controlling the moving platform to drive the inspection product to move along the first direction, finishing the height adjustment of the moving platform according to the defocusing amount of the at least two different detection positions when the at least two different detection positions reach the lower part of the camera unit, simultaneously controlling the camera unit to acquire images of the at least two different detection positions, and controlling the image processing device to finish the focal depth correction of the images of the at least two different detection positions and the defect identification of the images after the focal depth correction according to the defocusing amount corresponding to the at least two different detection positions and the height adjustment value of the moving platform.
In a second aspect, an embodiment of the present invention further provides a method for controlling an optical detection apparatus, where the method is applied to a controller of the optical detection apparatus, and includes:
controlling a defocusing measurement unit to acquire defocusing amounts at least two different detection positions on the surface of the inspection object; controlling a motion platform to drive a test object to move along a first direction, completing height adjustment of the motion platform according to defocusing amount of at least two different detection positions when the at least two different detection positions reach the lower part of a camera unit, and simultaneously controlling the camera unit to acquire images of the at least two different detection positions, wherein the at least two different detection positions are distributed along a second direction and are positioned in the same image, and the first direction is vertical to the second direction;
and controlling the image processing device to finish the focal depth correction of the images at the at least two different detection positions and the defect identification of the images after the focal depth correction according to the corresponding defocusing amount at the at least two different detection positions and the height adjustment value of the motion platform.
Compared with the prior art, the technical scheme of the optical detection equipment provided by the embodiment of the invention has the advantages that the image processing device does not directly identify the defects of the received image, and firstly carries out focal depth correction on the image of the part of the inspection product corresponding to at least two defocusing amounts according to the at least two defocusing amounts of any part of the inspection product and the height adjustment values of the motion table corresponding to the at least two defocusing amounts so as to obtain the image after focal depth correction. The quality of the images of the part of the inspection product corresponding to the at least two defocus amounts is greatly improved through the focal depth correction, so that the defect identification accuracy of the inspection product can be greatly improved by carrying out defect identification on the basis of the images after the focal depth correction, and the hardware cost of equipment does not need to be increased.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an optical detection apparatus according to an embodiment of the present invention;
FIG. 2 is a block diagram of an optical inspection apparatus according to an embodiment of the present invention;
FIG. 3 is a defocused image provided by an embodiment of the present invention;
FIG. 4 is a focal depth corrected image according to an embodiment of the present invention;
fig. 5 is a flowchart of a control method of an optical detection apparatus according to a second embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described through embodiments with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
An embodiment of the present invention provides an optical detection apparatus, as shown in fig. 1 and fig. 2, the apparatus includes a moving stage 11, a defocus measurement unit 12, an image pickup unit 13, an image processing device 14, and a controller 15, where the moving stage 11 is configured to drive the inspection object 2 to move in a first direction; the defocusing measurement unit 12 and the camera unit 13 are both positioned right above the moving table 11; the defocusing measurement unit 12 is used for acquiring defocusing amount at least two different detection positions of the surface of the inspection product, wherein the at least two different detection positions are distributed along a second direction, and the first direction is perpendicular to the second direction; the camera unit 13 is configured to acquire images at least two different detection positions on the surface of the inspection object, where the at least two different detection positions are located in the same image; the image processing device 14 is used for performing the focal depth correction of the images at the at least two different detection positions and the defect identification of the images after the focal depth correction; the controller 15 is used for controlling the defocusing measurement unit 12 to collect defocusing amounts at least two different detection positions of the surface of the inspection product; controlling the motion platform to drive the inspection product to move along a first direction, completing height adjustment of the motion platform 11 according to the defocusing amount of the at least two different detection positions when the at least two different detection positions reach the lower part of the camera unit 13, and simultaneously controlling the camera unit 13 to acquire images of the at least two different detection positions; the image processing device 14 is controlled to complete the focal depth correction of the images at the at least two different detection positions according to the defocus amounts at the at least two different detection positions, and to complete the defect identification of the images after the focal depth correction.
Illustratively, the defocus measurement unit 12 and the camera unit 13 are discretely distributed along a first direction above the motion stage, and the defocus measurement unit 12 includes at least two detection probes discretely distributed along a second direction, and the at least two detection probes preferably acquire defocus amounts at least two different detection positions of the surface of the test object under the control of the same pulse. It can be understood that the coordinates of the first direction at least two different detection positions on the surface of the test object corresponding to the defocus amount acquired by the defocus measurement unit each time are the same, the coordinates of the second direction are different, and the first direction is perpendicular to the second direction.
When the moving table 11 moves along the first direction, the detection object 2 on the moving table is driven to move, and at least two different detection positions where the defocus amount has been detected on the surface of the detection object 2 are located in the visual field area of the camera unit 13, the controller 15 adjusts the height of the moving table 11 according to the defocus amounts at the at least two different detection positions, and simultaneously controls the camera unit 13 to acquire images at the at least two different detection positions; namely, the detection product 2 finishes the defocusing amount acquisition firstly and then finishes the image acquisition in the moving process along with the moving platform 11. Preferably, the lens of the imaging unit 13 is at the same height as the defocus measurement unit 12.
Since the defocus measurement unit 12 can simultaneously collect the defocus amounts of at least two different detection positions on the surface of the specimen, and the defocus amounts of the at least two different detection positions may be the same or different, the adjustment value of the height of the motion stage 11 is determined according to the average value of the defocus amounts of the at least two different detection positions. Specifically, if the mean value of the defocus amounts at the at least two different detection positions is positive M units, the height of the moving stage 11 rising by M units is adjusted when the image capturing unit captures images at the at least two different detection positions; if the mean value of the defocus amounts at the at least two different detection positions is negative N units, when the image acquisition is performed at the at least two different detection positions by the camera unit, the height of the moving table which descends by N units is adjusted, that is, the defocus amounts at the at least two different detection positions of the inspection product are compensated by adjusting the height of the moving table 11, so that clear images at the at least two different detection positions are obtained.
It can be understood that if a large concave area exists on the surface of the test object, the defocusing amount at least two different detection positions in the concave area may have a large range difference, and after the height of the moving table is adjusted according to the method, the defocusing amount at least one detection position may not be completely corrected, so that the image at the detection position still has the problem of being unclear due to defocusing.
In order to solve the above problem, further, the defocus amount obtained in the present embodiment is used to correct the image focal depth in addition to the height of the stage. Specifically, the defocusing measurement unit collects defocusing amounts of at least two different detection positions on the surface of the inspection product in real time, the collected defocusing amounts and coordinates of the detection positions on the surface of the inspection product corresponding to the defocusing amounts are sent to the image processing device, meanwhile, the controller obtains the defocusing amounts of at least two different detection positions based on the defocusing measurement unit to adjust the height of the motion table, so that the image pickup unit collects images of detection position areas on the surface of the inspection product corresponding to the defocusing amounts of the at least two different detection positions, and the image pickup unit sends the collected images of the at least two different detection positions and the coordinates of the detection positions corresponding to the images to the image processing device. The image processing device determines the defocusing amount of at least two different detection positions corresponding to the image according to the coordinates of the detection position corresponding to the image, then takes the difference value of the defocusing amount of each detection position and the corresponding moving table height adjustment value as the corrected defocusing amount of each detection position, so that the corrected defocusing amount of each detection position in the image can be determined, and then performs focus depth correction on the image according to the corrected defocusing amount of each detection position in the image to obtain a focus depth corrected image.
After the image is subjected to focal depth correction, the image quality is greatly improved, so that the accuracy of a defect identification result obtained by defect identification on the image subjected to focal depth correction is far greater than that obtained by directly performing defect identification on the image acquired by the camera unit.
Preferably, the height adjustment value of the motion stage is an average value of defocus amounts at least two different detection positions acquired simultaneously, and a difference value between the defocus amount at each detection position and the average value is used as a corrected defocus amount at each detection position in the corresponding image.
When the image collected by the camera unit is subjected to the focal depth correction, the image processing device performs the focal depth correction on the image according to the point spread function and the corrected defocusing amount of the image at each detection position to obtain an image after the focal depth correction. The point spread function is used for representing a spatial distribution diagram of point image energy formed by sampling an ideal point under different defocusing conditions by the CCD.
The image processing apparatus may be only one image processor, or may be composed of two image processors, and the specific use may be selected according to the data processing amount and the equipment cost. In some embodiments, the image processing apparatus includes a first image processing apparatus and a second image processing apparatus, wherein the first image processing apparatus is configured to calculate a difference between a defocus amount at least two different detection positions of the surface of the test object and a height adjustment value of the motion stage corresponding to the at least two different detection positions as a corrected defocus amount of the image at the at least two different detection positions, and then complete a depth-of-focus correction of the corresponding image according to the corrected defocus amount. And the second image processing device performs defect identification on the image after the focal depth correction to obtain a defect identification result of the inspection product. Note that, the defect identification may be performed by using a conventional defect identification method, and this embodiment is not particularly limited herein.
For example, if the image capturing unit has a defocus problem during image capturing, the obtained image may be blurred, and lines (see fig. 4) that are not originally connected may be connected due to the blurring of the image (see fig. 3), and thus may be erroneously determined as a defect during defect recognition of the image. Before defect identification is performed on fig. 3, the image processing apparatus of this embodiment collects defocus amounts at least two different detection positions on the surface of the inspection product, determines corrected defocus amounts at the at least two different detection positions according to the at least two defocus amounts and height adjustment values of the motion stage corresponding to the at least two defocus amounts, and corrects the image depth according to the corresponding corrected defocus amounts to obtain an image with the corrected depth. And after the image after the focal depth correction is obtained, carrying out defect identification on the image after the focal depth correction to obtain a defect identification result.
Since fig. 3 and fig. 4 are greatly different, the defect identification results of the two are quite opposite, fig. 3 has a line blurring due to defocusing, and fig. 4 restores the original appearance of the inspection product after defocusing correction, so that the defect identification result based on fig. 4 is accurate, and the identification result based on fig. 3 is wrong, and thus, the optical detection device according to the embodiment can greatly improve the accuracy of defect identification of the inspection product.
Compared with the prior art, the technical scheme of the optical detection equipment provided by the embodiment of the invention has the advantages that the image processing device does not directly identify the defects of the received image, and firstly carries out focal depth correction on the image of the part of the inspection product corresponding to at least two defocusing amounts according to the at least two defocusing amounts of any part of the inspection product and the height adjustment values of the motion table corresponding to the at least two defocusing amounts so as to obtain the image after focal depth correction. The quality of the images of the part of the inspection product corresponding to the at least two defocus amounts is greatly improved through the focal depth correction, so that the defect identification accuracy of the inspection product can be greatly improved by carrying out defect identification on the basis of the images after the focal depth correction, and the hardware cost of equipment does not need to be increased.
Example two
Fig. 4 is a flowchart of a control method of an optical detection apparatus according to a second embodiment of the present invention. The technical scheme of the embodiment is suitable for controlling the optical detection equipment to automatically complete the defect identification of the inspected product. The method can be executed by a controller of the optical detection device provided by the embodiment of the invention, and the device can be implemented in a software and/or hardware manner and configured to be applied in a processor. With reference to fig. 1 and 2, the method specifically includes the following steps:
s101, controlling a defocusing measurement unit to collect defocusing amount of at least two different detection positions on the surface of the inspection product; the motion platform is controlled to drive the inspection object to move along a first direction, when the at least two different detection positions reach the lower part of the camera unit, the height of the motion platform is adjusted according to the defocusing amount of the at least two different detection positions, and the camera unit is controlled to collect images of the at least two different detection positions, wherein the at least two different detection positions are distributed along a second direction and are located in the same image, and the first direction is perpendicular to the second direction.
Illustratively, the defocus measurement unit 12 and the camera unit 13 are discretely distributed along a first direction above the motion stage, and the defocus measurement unit 12 includes at least two detection probes discretely distributed along a second direction, and the at least two detection probes preferably acquire defocus amounts at least two different detection positions of the surface of the test object under the control of the same pulse. It can be understood that the coordinates of the first direction at least two different detection positions on the surface of the test object corresponding to the defocus amount acquired by the defocus measurement unit each time are the same, the coordinates of the second direction are different, and the first direction is perpendicular to the second direction.
When the moving table 11 moves along the first direction, the detection object 2 on the moving table is driven to move, and at least two different detection positions where the defocus amount has been detected on the surface of the detection object 2 are located in the visual field area of the camera unit 13, the controller 15 adjusts the height of the moving table 11 according to the defocus amounts at the at least two different detection positions, and simultaneously controls the camera unit 13 to acquire images at the at least two different detection positions; namely, the detection product 2 finishes the defocusing amount acquisition firstly and then finishes the image acquisition in the moving process along with the moving platform 11. Preferably, the lens of the imaging unit 13 is at the same height as the defocus measurement unit 12.
Since the defocus measurement unit 12 can simultaneously collect the defocus amounts of at least two different detection positions on the surface of the specimen, and the defocus amounts of the at least two different detection positions may be the same or different, the adjustment value of the height of the motion stage 11 is determined according to the average value of the defocus amounts of the at least two different detection positions. Specifically, if the mean value of the defocus amounts at the at least two different detection positions is positive M units, the height of the moving stage 11 rising by M units is adjusted when the image capturing unit captures images at the at least two different detection positions; if the mean value of the defocus amounts at the at least two different detection positions is negative N units, when the image acquisition is performed at the at least two different detection positions by the camera unit, the height of the moving table which descends by N units is adjusted, that is, the defocus amounts at the at least two different detection positions of the inspection product are compensated by adjusting the height of the moving table 11, so that clear images at the at least two different detection positions are obtained.
It can be understood that when the controller 15 adjusts the height of a certain portion of the inspection product by the moving stage 11, it is necessary to acquire defocus amounts at least two different inspection positions of the inspection product, then determine an adjustment value of the height of the moving stage 11 according to the defocus amounts at the at least two different inspection positions, and acquire an acquisition time of the defocus amounts at the at least two different inspection positions and an effective movement time at the at least two different inspection positions. In this way, timing is started from when the defocus amounts at the at least two different detection positions are detected, and when the timing reaches the effective movement time, the height adjustment is performed on the moving stage 11. The effective movement time is determined according to the distance between the defocus measurement unit and the imaging unit and the movement speed of the movement table, but under the condition that the distance between the defocus measurement unit and the imaging unit is constant and the movement speed of the movement table is not changed, the effective movement time of the part is the ratio of the distance to the movement speed.
S102, controlling the image processing device to finish the focal depth correction of the images at the at least two different detection positions according to the corresponding defocusing amount at the at least two different detection positions and the height adjustment value of the motion platform, and finishing the defect identification of the images after the focal depth correction.
It can be understood that if a large concave area exists on the surface of the test object, the defocusing amount at least two different detection positions in the concave area may have a large range difference, and after the height of the moving table is adjusted according to the method, the defocusing amount at least one detection position may not be completely corrected, so that the image at the detection position still has the problem of being unclear due to defocusing.
In order to solve the above problem, further, the defocus amount obtained in the present embodiment is used to correct the image focal depth in addition to the height of the stage. Specifically, the defocusing measurement unit collects defocusing amounts of at least two different detection positions on the surface of the inspection product in real time, the collected defocusing amounts and coordinates of the detection positions on the surface of the inspection product corresponding to the defocusing amounts are sent to the image processing device, meanwhile, the controller acquires the defocusing amounts of at least two different detection positions based on the defocusing measurement unit to adjust the height of the motion table, so that the image pickup unit collects images of detection position areas on the surface of the inspection product corresponding to the defocusing amounts of the at least two different detection positions, and the image pickup unit sends the collected images of the at least two different detection positions and the coordinates of the detection positions corresponding to the images to the image processing device. The image processing device determines the defocusing amount of at least two different detection positions corresponding to the image according to the coordinates of the detection position corresponding to the image, then takes the difference value of the defocusing amount of each detection position and the corresponding moving table height adjustment value as the corrected defocusing amount of each detection position, so that the corrected defocusing amount of each detection position in the image can be determined, and then performs focus depth correction on the image according to the corrected defocusing amount of each detection position in the image to obtain a focus depth corrected image.
After the image is subjected to focal depth correction, the image quality is greatly improved, so that the accuracy of a defect identification result obtained by defect identification on the image subjected to focal depth correction is far greater than that obtained by directly performing defect identification on the image acquired by the camera unit.
Preferably, the height adjustment value of the motion stage is an average value of defocus amounts at least two different detection positions acquired simultaneously, and a difference value between the defocus amount at each detection position and the average value is used as a corrected defocus amount at each detection position in the corresponding image.
When the image collected by the camera unit is subjected to the focal depth correction, the image processing device performs the focal depth correction on the image according to the point spread function and the corrected defocusing amount of the image at each detection position to obtain an image after the focal depth correction. The point spread function is used for representing a spatial distribution diagram of point image energy formed by sampling an ideal point under different defocusing conditions by the CCD.
The image processing apparatus may be only one image processor, or may be composed of two image processors, and the specific use may be selected according to the data processing amount and the equipment cost. In some embodiments, the image processing apparatus includes a first image processing apparatus and a second image processing apparatus, wherein the first image processing apparatus is configured to calculate a difference between a defocus amount at least two different detection positions of the surface of the test object and a height adjustment value of the motion stage corresponding to the at least two different detection positions as a corrected defocus amount of the image at the at least two different detection positions, and then complete a depth-of-focus correction of the corresponding image according to the corrected defocus amount. And the second image processing device performs defect identification on the image after the focal depth correction to obtain a defect identification result of the inspection product. Note that, the defect identification may be performed by using a conventional defect identification method, and this embodiment is not particularly limited herein.
For example, if the image capturing unit has a defocus problem during image capturing, the obtained image may be blurred, and lines (see fig. 4) that are not originally connected may be connected due to the blurring of the image (see fig. 3), and thus may be erroneously determined as a defect during defect recognition of the image. Before defect identification is performed on fig. 3, the image processing apparatus of this embodiment collects defocus amounts at least two different detection positions on the surface of the inspection product, then determines corrected defocus amounts at the at least two different detection positions according to the at least two defocus amounts and height adjustment values of the motion stage corresponding to the at least two defocus amounts, and then performs depth correction on the image according to the corresponding corrected defocus amounts to obtain a depth-of-focus corrected image. And after the image after the focal depth correction is obtained, carrying out defect identification on the image after the focal depth correction to obtain a defect identification result.
Since fig. 3 and fig. 4 are greatly different, the defect identification results of the two are quite opposite, fig. 3 has a blurring line due to defocusing, and fig. 4 restores the original appearance of the inspection product after defocusing correction, so that the defect identification result based on fig. 4 is accurate, and the identification result based on fig. 3 is wrong, and thus, the optical detection apparatus according to the embodiment can greatly improve the accuracy of defect identification of the inspection product.
Compared with the prior art, the technical scheme of the control method of the optical detection equipment provided by the embodiment of the invention has the advantages that the image processing device does not directly identify the defects of the received image, and firstly carries out focal depth correction on the image of the part of the inspection product corresponding to at least two defocusing amounts according to the at least two defocusing amounts of any part of the inspection product and the height adjustment values of the motion platform corresponding to the at least two defocusing amounts so as to obtain the image after focal depth correction. The quality of the images of the part of the inspection product corresponding to the at least two defocus amounts is greatly improved through the focal depth correction, so that the defect identification accuracy of the inspection product can be greatly improved by carrying out defect identification on the basis of the images after the focal depth correction, and the hardware cost of equipment does not need to be increased.
EXAMPLE III
A third embodiment of the present invention further provides a storage medium containing computer-executable instructions, which when executed by a computer processor, are configured to perform a method for controlling an optical inspection apparatus, the method including:
controlling a defocusing measurement unit to acquire defocusing amounts at least two different detection positions on the surface of the inspection object; controlling a motion platform to drive a test object to move along a first direction, completing height adjustment of the motion platform according to defocusing amount of at least two different detection positions when the at least two different detection positions reach the lower part of a camera unit, and simultaneously controlling the camera unit to acquire images of the at least two different detection positions, wherein the at least two different detection positions are distributed along a second direction and are positioned in the same image, and the first direction is vertical to the second direction;
and controlling the image processing device to finish the focal depth correction of the images at the at least two different detection positions and the defect identification of the images after the focal depth correction according to the corresponding defocusing amount at the at least two different detection positions and the height adjustment value of the motion platform.
Of course, the storage medium containing the computer-executable instructions provided by the embodiments of the present invention is not limited to the method operations described above, and may also perform related operations in the control method of the optical detection apparatus provided by any embodiments of the present invention.
From the above description of the embodiments, it is obvious for those skilled in the art that the present invention can be implemented by software and necessary general hardware, and certainly, can also be implemented by hardware, but the former is a better embodiment in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, where the computer software product may be stored in a computer-readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, and the like, and includes several instructions to enable a computer device (which may be a personal computer, a server, or a network device, and the like) to execute the control method of the optical detection apparatus according to the embodiments of the present invention.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims (9)
1. An optical inspection apparatus, comprising:
the motion platform is used for driving the inspection product to move along a first direction;
the defocusing measuring unit is arranged right above the moving table and used for collecting defocusing amount at least two different detection positions on the surface of the inspection object, wherein the at least two different detection positions are distributed along a second direction, and the first direction is vertical to the second direction;
the camera shooting unit is arranged right above the motion table and used for collecting images at the at least two different detection positions, wherein the at least two different detection positions are positioned in the same image;
image processing means for performing focus depth correction of the images at the at least two different detection positions and defect identification of the focus depth-corrected images;
the controller is used for controlling the defocusing measuring unit to acquire defocusing amounts at least two different detection positions of the surface of the inspection object; and controlling the moving platform to drive the inspection product to move along the first direction, finishing the height adjustment of the moving platform according to the defocusing amount of the at least two different detection positions when the at least two different detection positions reach the lower part of the camera unit, simultaneously controlling the camera unit to acquire images of the at least two different detection positions, and controlling the image processing device to finish the focal depth correction of the images of the at least two different detection positions and the defect identification of the images after the focal depth correction according to the defocusing amount corresponding to the at least two different detection positions and the height adjustment value of the moving platform.
2. The apparatus according to claim 1, wherein the defocus measuring unit and the imaging unit are discretely distributed along the first direction; the defocusing measuring unit comprises at least two detection probes discretely distributed along the second direction, and the at least two detection probes are used for acquiring defocusing amounts at least two different detection positions of the surface of the inspection object.
3. The apparatus of claim 1, wherein when the motion stage moves the at least two different detection positions of the test object to the position below the image capturing unit, the controller completes the height adjustment of the motion stage according to the average value of the defocus amounts at the at least two different detection positions.
4. The apparatus of claim 1, wherein the method for correcting the focal depth of the image comprises:
taking the difference value between the defocusing amount at the at least two different detection positions in the image and the height adjustment value of the corresponding motion platform as the corrected defocusing amount at each detection position;
and completing the focal depth correction of the corresponding image according to the corrected defocus amount and the point spread function to obtain an image after the focal depth correction.
5. The apparatus according to claim 1, characterized in that the image processing means comprises:
the first image processing device is used for finishing the focal depth correction of the images at the at least two different detection positions according to the defocusing amount at the at least two different detection positions and the height adjustment value of the motion platform corresponding to the at least two defocusing amounts;
and the second image processing device is used for finishing the defect identification of the image after the focal depth correction.
6. A control method of an optical inspection apparatus, characterized in that a controller applied to the optical inspection apparatus includes:
controlling a defocusing measurement unit to acquire defocusing amounts at least two different detection positions on the surface of the inspection object; controlling a motion platform to drive a test object to move along a first direction, completing height adjustment of the motion platform according to defocusing amount of at least two different detection positions when the at least two different detection positions reach the lower part of a camera unit, and simultaneously controlling the camera unit to acquire images of the at least two different detection positions, wherein the at least two different detection positions are distributed along a second direction and are positioned in the same image, and the first direction is vertical to the second direction;
and controlling the image processing device to finish the focal depth correction of the images at the at least two different detection positions and the defect identification of the images after the focal depth correction according to the corresponding defocusing amount at the at least two different detection positions and the height adjustment value of the motion platform.
7. The method of claim 6, wherein the height adjustment of the motion stage comprises:
and when the controller controls the motion platform to drive the at least two different detection positions of the test object to reach the lower part of the camera unit, the height adjustment amount of the motion platform is completed according to the mean value of the defocusing amounts of the at least two different detection positions.
8. The method of claim 6, wherein the image depth-of-focus correction method comprises:
taking the difference value between the defocusing amount at the at least two detection positions in the image and the height adjustment value of the corresponding motion platform as the corrected defocusing amount of the image at each detection position;
and completing the focal depth correction of the corresponding image according to the corrected defocus amount and the point spread function to obtain an image after the focal depth correction.
9. A storage medium containing computer-executable instructions for performing the method of controlling an optical detection apparatus according to any one of claims 6 to 8 when executed by a computer processor.
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