JP4128613B1 - Drill inspection device - Google Patents

Abstract

It is difficult to judge the timing of drill polishing and disposal without variation.
A setting unit is generated by sampling a plurality of pieces of start point information generated by sampling a plurality of pieces of shape information of a cutting edge region of an unused drill and a plurality of pieces of shape information of a cutting edge region of a drill to be used. Set the end point information. The storage unit 36 holds start point information and end point information set by the setting unit 35. The measuring unit 34 measures the shape information of the cutting edge region in the imaged cutting edge image of the drill. The determination unit 38 specifies the degree of wear of the imaged drill by calculation based on the shape information measured by the measurement unit 34 and the start point information and end point information held in the storage unit 36.
[Selection] Figure 3

Description

  The present invention relates to a drill inspection apparatus for inspecting a drill for making a hole in a printed circuit board or the like.

  As semiconductor processes become finer, holes that are drilled in printed circuit boards are required to have higher accuracy. The size and shape of the hole will change when the drill tip wears out or is missing, so it is necessary to inspect the tip of the drill and polish it if necessary to reuse or discard it . Generally, the timing of drill polishing and discarding is determined by the number of drilled holes.

Patent Document 1 discloses a method of determining pass / fail by comparing a reference value with a value obtained from drill blade data.
Japanese Patent Laid-Open No. 1-216752

  When the timing of drill polishing or discarding is determined by the number of holes, it may deviate from the original timing for polishing or discarding due to the difference in hardness or material of the substrate in which the holes are drilled. Moreover, when judging the timing of grinding | polishing and discarding artificially, a skilled inspector is required and work itself is complicated.

  This invention is made | formed in view of such a condition, The objective is to provide the drill test | inspection apparatus which can determine the state of a drill exactly with a simple process.

  A drill inspection apparatus according to an aspect of the present invention determines a state of a cutting edge of a drill from a measuring unit that measures shape information of a cutting edge region in a picked-up image of a cutting edge, and shape information measured by the measuring unit. A determination unit.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, the state of the drill can be accurately determined by a simple process.

  First, before describing the embodiment of the present invention in detail, the life cycle of a drill will be described. As the number of times of use of the drill increases, the respective cutting blades wear and the width of the cutting blade as viewed in the direction along the rotation axis becomes narrower. When the cutting blade is worn to such an extent that the accuracy of the drilled hole is impaired, the cutting edge portion is sharpened by polishing and used repeatedly, thereby extending the life of the drill. Such polishing is often performed multiple times before the drill is discarded to reduce costs. From this viewpoint, the life cycle of the drill can be classified into a plurality of stages according to the number of times of polishing. Moreover, it can classify | categorize into the state which should use the drill which the grinding | polishing of the same number of times was performed, and the state which should not be used because wear progresses.

  FIG. 1 is a diagram for explaining stages on the life cycle of a drill. In FIG. 1, the state of zero polishing is a first stage, the state of one polishing is a second stage, and the state of two polishings is a third stage. When further polishing is performed, the stage is further advanced. Hereinafter, an example of three stages will be described in this specification. In the present specification, the first half of each of the first stage, the second stage, and the third stage is referred to as a first half stage, and the second half of each stage is referred to as a second half stage.

  FIG. 2 is a diagram showing a cutting edge state of a drill having two cutting edges. FIG. 2A is a diagram in which the cutting edge of a new drill (0 polishing) in an unused state is imaged in a direction along the rotation axis, and FIG. 2B shows the cutting edge of a new drill (0 polishing) in a used state. FIG. 2C is an image of the drill tip in an unused state after one polishing, and FIG. 2D is an image of the drill tip in a used state after one polishing. FIG. 2E is a diagram in which the blade edge of the drill after the second polishing is imaged, FIG. 2F is a diagram in which the blade edge of the drill in the used state after the second polishing is imaged, and FIG. 2G is in a defective state. It is the figure which imaged the blade edge of the drill. Here, the used state is not limited to a state in which accuracy cannot withstand use objectively, but may be a state in which the user has determined that the polishing should be subjectively performed. Therefore, even if the drill can objectively withstand use, it can correspond to being used.

  FIG. 3 is a diagram showing a configuration of the drill inspection apparatus 100 according to the embodiment of the present invention. The drill inspection apparatus 100 includes an imaging unit 20, a calculation unit 30, and a display unit 40. The calculation unit 30 includes an image processing unit 32, a measurement unit 34, a setting unit 35, a storage unit 36, and a determination unit 38. The configuration of the arithmetic unit 30 can be realized by a CPU, memory, or other LSI of an arbitrary computer in hardware, and can be realized by an image processing program or a numerical analysis program loaded in the memory in software. Here, however, the functional blocks realized by the cooperation are depicted. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof. The calculation unit 30 may be realized by cooperation of an observation apparatus including the imaging unit 20 and a general-purpose computer. The calculation unit 30 includes the image processing unit 32 and the measurement unit 34 in the observation device, and includes a setting unit 35, a storage unit 36, and a determination unit. The unit 38 may be included in a general purpose computer.

  The imaging unit 20 images the cutting edge of the drill 10 in a direction along the rotation axis. The imaging unit 20 includes a CCD (Charge Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and acquires an image of the cutting edge of the drill 10 projected by a light source (not shown). In this embodiment, since simple parameters are used as will be described later, a low-resolution image may be used. For example, a φ0.5 drill is imaged with about three times the optical power. The imaging unit 20 converts the acquired image including the cutting edge of the drill 10 into an electrical signal and outputs the electrical signal to the image processing unit 32.

  The computing unit 30 identifies a predetermined parameter with reference to an area (hereinafter referred to as a cutting edge area) in which an edge is captured in an image captured by the imaging unit 20, and determines the degree of drill wear or the drill's wear from the parameter. Determine the number of polishes over the life cycle, or both. The predetermined parameter is defined in n (n is a natural number) dimension, and includes at least one of the length, width, and area, average, and variance obtained from the shape curve connecting the cutting edge widths. Moreover, you may include any one of the area obtained from the shape curve which tied the length of the cutting edge, an average, and dispersion | distribution. It may also include the tangent or angle of the contour of the cutting edge region. Further, the information is not limited to the information obtained from the shape of the blade edge, and may include the number of holes formed. Details of these parameters will be described later.

  The image processing unit 32 adjusts the density value of the image input from the imaging unit 20. Specifically, each pixel value is binarized using a predetermined threshold value, and the cutting edge region is adjusted to “0” or “1”, and the background region is adjusted to “1” or “0”.

  The image processing unit 32 aligns binarized images. For example, the position of the tip on the center side of the cutting edge (hereinafter simply referred to as the tip in the present specification) and the position of the tip on the outer peripheral side of the cutting blade (hereinafter referred to as an edge in the specification) in the image are predetermined standards. Move or rotate the cutting edge area to match the position.

  The measuring unit 34 measures the shape information of the cutting edge region in the image processed by the image processing unit 32. The shape information is information obtained from the shape of the blade edge among the above parameters. For example, the length and width of the cutting edge region are applicable.

  The setting unit 35 sets reference data of shape information of the cutting edge region of the drill in the storage unit 36. As this reference data, for example, start point information generated by sampling a plurality of shape information of the cutting edge area of an unused drill, and an end generated by sampling a plurality of shape information of the cutting edge area of a drill that should be used Set point information. The reference data is data generated by learning from a large number of sampling images. The sampling image may be a regular image captured by the system designer or may be captured under conditions actually used by the user. In the latter case, at least one of the start point information and the end point information is generated by imaging a large number of shape information of the cutting edge region of the drill that should be used by the user with the imaging unit 20 of the drill inspection apparatus 100. May be.

  The storage unit 36 holds reference data for shape information of the cutting edge region of the drill set by the setting unit 35. When the start point information and the end point information are set from the setting unit 35, they are held as the reference data.

  The determination unit 38 calculates the degree of wear of the drill imaged by the imaging unit 20 based on the shape information measured by the measurement unit 34 and the start point information and end point information held in the storage unit 36. Specified. For example, the determination unit 38 virtually forms a coordinate space having the elements constituting the shape information as coordinate axes, and in the coordinate space, the start coordinate position of the start point information and the end coordinate position of the end point information are The degree of wear of the imaged drill is specified from the positional relationship with the input coordinate position of the shape information measured by the measurement unit 34.

  When the coordinate space is a two-dimensional space defined by the length and width of the cutting edge region, for example, the start point information and the end point information can be generated as follows. An average value of the length and width of the cutting edge region can be calculated from a plurality of sampling images of unused drills to obtain representative points such as the center of gravity, and this can be used as starting point information. Similarly, the average value of the length and width of the cutting edge region can be calculated from a plurality of sampling images of the drill that should be used, and the center of gravity can be obtained, which can be used as end point information.

  In the coordinate space, the determination unit 38 draws an interpolation line between the start coordinate position and the end coordinate position, draws a perpendicular line from the input coordinate position to the interpolation line, and according to the position of the intersection, The degree of wear can be specified. The degree of wear can be specified by how much the intersection point is located on the interpolation line. For example, when the intersection is located at a point where the interpolation line is divided into 3: 7, the degree of wear can be specified as 30%. The unit to be divided may be 100 divisions, 10 divisions, or others.

  In the above, it is assumed that the interpolation line is a straight line, but a transition line closer to the substance may be used. In this case, the storage unit 36 further holds a transition function indicating the transition state of the shape information of the cutting edge region from the unused state to the used state. The determination unit 38 specifies the degree of wear from the positional relationship between the transition line derived from the transition function and the input coordinate position. Details of this processing will be described later.

  Up to this point, the case where there is one stage in the life cycle, that is, an embodiment that can be applied to a disposable drill has been described. From here, an embodiment that assumes the case where there are multiple stages in the life cycle will be described. To do.

  The memory | storage part 36 hold | maintains the said reference data, for example, the said starting point information and end point information for every several stage on a life cycle corresponding to the frequency | count of grinding | polishing of a drill. Based on the shape information measured by the measurement unit 34, the determination unit 38 identifies the stage to which the imaged drill corresponds and the degree of wear in the stage.

  For example, the stage to which the drill corresponds can be specified as follows. In this case, the storage unit 36 virtually forms a coordinate space having the elements constituting the shape information as coordinate axes, and the start coordinate position of the start point information and the end coordinate position of the end point information in the coordinate space. For each stage. The determination unit 38 specifies the closest coordinate position among the start coordinate position and the end coordinate position held for each stage from the input coordinate position in the coordinate space of the shape information measured by the measurement unit 34. The stage to which the coordinate position belongs is specified as the stage to which the imaged drill corresponds.

  For example, the degree of wear of the stage to which the drill corresponds can be specified as follows. In this case, the memory | storage part 36 further hold | maintains the change characteristic prescribed | regulated by the shape information of the said blade edge | tip area | region by use of a drill, for example, length and width | variety per stage. The determination unit 38 obtains the degree of wear in the stage to which the drill corresponds by checking the shape information measured by the measurement unit 34, for example, the length and width, and the change characteristics held in the storage unit 36. As the change characteristic, the interpolation straight line or the transition line can be used.

  Here, the change characteristic may be generated based on actual sampling data. For example, in a usage mode in which holes are continuously drilled in the same object under the same environment, a large number of change characteristics of the shape information with respect to the increasing direction of the number of holes drilled may be sampled, and the average characteristics may be used.

  So far, the embodiment for identifying the degree of wear of the imaged drill has been described. However, the embodiment for identifying only the corresponding stage without specifying the degree of wear is also effective as an embodiment of the present invention. This will be described below.

  The determination unit 38 identifies the stage on the life cycle reflecting the number of polishings to which the drill corresponds from the shape information measured by the measurement unit 34. This stage may be a stage corresponding to the number of times of polishing, or may be a first half stage or a second half stage obtained by dividing the stage in half.

  The length and width of the cutting edge region can be used as the shape information. In this case, the storage unit 36 holds reference data for the length and width of the edge region of the drill for each stage reflecting the number of polishings in the life cycle of the drill. The reference data can use the start point information and the end point information. The determination unit 38 identifies the stage to which the drill to be inspected corresponds by comparing the length and width of the cutting edge region measured by the measurement unit 34 with the reference data for each stage held in the storage unit 36. . In the embodiment described above, the stage corresponding to the number of times of polishing is specified, but here it is possible to specify whether the stage is located in the first half stage or the second half stage. For example, when the measured length and width of the cutting edge region are closest to the starting point information of the Nth (N is a natural number) stage, it can be identified as the first half stage of the Nth stage.

  In addition, it can be specified by the following method whether it is located in the first half stage or the second half stage of the Nth stage. That is, in the two-dimensional space, the shape information of the cutting edge region obtained from the sampling images of the unused drills and the drills to be used for each polishing number is plotted. Based on the result, a predetermined linear classifier or non-linear classifier such as a neural network or a support vector machine is constructed. Thereby, the two-dimensional space can be divided into a first stage to an Mth (M = maximum polishing count + 1) stage divided into a first half stage and a second half stage, respectively. In this case, data for specifying each region, such as a boundary line of each region, is the reference data. Note that a defect stage may be included when the two-dimensional space is divided into regions. The defect stage can be identified based on the shape information of the cutting edge region obtained from the image of the drill in the defect state. Further, the extension of each stage from the first stage to the M-th stage may be specified, and a region between them may be set as a defective stage. For example, a defect stage may be provided in a region between the first stage and the second stage or a region between the second stage and the third stage. As will be described later, the same applies to a space defined by three or more parameters.

In addition to the length and width of the cutting edge region, the area obtained by a predetermined method can be added as the shape information. In this case, the storage unit 36 uses, as part of the reference data, an area obtained by integrating the width of the cutting blade included in the blade edge region by a predetermined length from the edge of the cutting blade in the longitudinal direction. Hold further with. The measuring unit 34 measures the width of the cutting edge included in the cutting edge region of the drill to be inspected by at least the predetermined length in the longitudinal direction. The determination unit 38 obtains an area by integrating the width of the cutting edge measured by the measurement unit 34, and obtains the length, width, and area measured by the measurement unit 34 and the reference data held in the storage unit 36. Match.
In addition to the length and width of the cutting edge region, a shape curve obtained by a predetermined method can be added as the shape information. In this case, the storage unit 36 further holds a shape curve connecting the widths of the cutting blades included in the blade edge region in the longitudinal direction as a part of the reference data in units of stages. The measuring unit 34 measures a shape curve that connects the widths of the cutting blades included in the cutting edge region of the drill to be inspected in the longitudinal direction. The determination unit 38 collates the length, width, and shape curve measured by the measurement unit 34 with reference data held in the storage unit 36. Further, the length information of the cutting edge region, the area, and the shape curve may be used as the shape information. Details of these processes will be described later.

  The display unit 40 displays the degree of wear specified by the determination unit 38. Alternatively, the stage on the life cycle to which the inspection target drill is specified, which is specified by the determination unit 38, is displayed. For example, it may be displayed that it is located on the Nth stage, or may be displayed if it is located on the first half or the latter half of the Nth stage. Alternatively, the display unit 40 displays the stage on the life cycle to which the drill to be inspected specified by the determination unit 38 and the degree of wear in the stage are displayed. The degree of wear is 0 to 50% for the first half stage and 51 to 100% for the second half stage, and 0 to 100% for the entire stage.

  Further, the display unit 40 may display a message that informs the inspector of the state of the cutting edge and prompts polishing or discarding. Further, an image of the cutting edge region imaged by the imaging unit 20 may be displayed. Alternatively, when inspecting a plurality of cutting edges collectively in a cartridge, the state of each drill may be displayed in a tabular format or the like.

  FIG. 4 is a diagram for explaining parameters specified from an image including a cutting edge region. In FIG. 4, the length L of the cutting edge region constituted by two cutting edges is defined by the length between the coordinate values in the longitudinal direction of the sharpest position on each edge side of the two cutting edges. The It almost matches the diameter of the drill blade. The width W of the blade edge region is defined by the length between the coordinate values in the short direction of the position swelled to the outermost side in the two cutting blades. The two coordinate axes in FIG. 4 are defined by the number of pixels. This number of pixels can be converted to an actual length by referring to the photographing magnification and the enlargement ratio or reduction ratio in image processing.

  The measuring unit 34 may measure the widths X1 to Xm (m is a natural number) of each cutting edge for each row in the longitudinal direction in addition to the length L and the width W of the cutting edge region. Moreover, you may measure length Y1-Yp (p is a natural number) of each cutting blade for every row | line | column in a transversal direction. When the widths X1 to Xm for each row of the cutting blades are connected, a shape curve relating to the widths X1 to Xm described later can be obtained.

  FIG. 5 is a diagram in which sample data is plotted in a two-dimensional parameter space defined by the shape information of the cutting edge region. This two-dimensional parameter space has a width on the vertical axis and a length on the horizontal axis. As the sample data, (1) Length data and width data of the cutting edge area of a new drill (0 polishing) unused, (2) Drill cutting edge of a new (0 polishing) used condition Area length data and width data, (3) Length data and width data of the drill tip area in an unused state after one polishing, and (4) Drill tip in a used state after one polishing. Area length data and width data, (5) Length data and width data of the drill tip area in an unused state after two rounds of polishing, (6) Drill tip in a used state after two rounds of polishing A total of seven types of sample data are plotted, ie, length data and width data of the region, and (7) length data and width data of the cutting edge region of the drill in the missing state.

  Here, when the linear discriminator or the non-linear discriminator is applied to the six types of sample data except for the length data and width data of the cutting edge in the defective state, the two-dimensional parameter space is classified into six regions. be able to. Each area can be set to the first half stage or the second half stage of each Nth stage.

  In FIG. 5, the first region R1 is the first half of the first stage, the second region R2 is the second half of the first stage, the third region R3 is the first half of the second stage, and the fourth region R4 is the second half of the second stage. The stage, the fifth region R5 can be set as the first half stage of the third stage, and the sixth region R6 can be set as the second half stage of the third stage. Thus, if the length and width of the cutting edge region of the drill to be inspected are known, it can be uniquely specified whether the first half stage or the second half stage of the Nth stage is applicable. Naturally, the number of times of polishing can also be specified uniquely. Moreover, you may obtain | require representative points, such as a gravity center, for every sample data of each state (1)-(6). In this case, it is possible to uniquely specify the stage and the number of polishings in the same manner by obtaining the closest representative point from the input data without performing the region division described above.

  FIG. 6 is a diagram for explaining a first processing example for identifying the degree of wear of a drill based on start point information and end point information. A start point P1 and an end point P2 are plotted in a coordinate space in which the length and width of the cutting edge region are respectively set to the X axis and the Y axis. The starting point P1 is a point that samples a plurality of coordinate points defined by the length and width of the cutting edge region of the unused drill and corresponds to the center of gravity of the sampling points. Similarly, the end point P2 is a point corresponding to the center of gravity of a plurality of coordinate points defined by the length and width of the edge region of the drill to be used.

  In the coordinate space, an unused area C1 centered on the start point P1 and a used area C2 centered on the end point P2 are formed. The unused area C1 is a circular area in which the deviation between each of the plurality of sampling coordinate points and the center of gravity in the unused drill is calculated and the average of these is used as the radius. Alternatively, the distance between the coordinate point farthest from the center of gravity and the center of gravity among the plurality of sampling coordinate points may be used as the radius. The used region C2 can be similarly formed.

  The determination unit 38 draws an interpolation line L1 between the start point P1 and the end point P2 when specifying the degree of wear of the inspection target drill. Then, the width and length of the cutting edge region of the drill measured by the measuring unit 34 are plotted as an input point P3, and a perpendicular line L2 is drawn from the input point P3 to the interpolation straight line L1. The degree of wear is specified by how much the intersection point P4 is located on the interpolation straight line L1. In addition, when the intersection P4 is made in the line segment located in the unused area | region C1 among the interpolation straight lines L1, the degree of wear is determined to be 0% in any part of the line segment. Similarly, when the intersection P4 is formed in the line segment located in the used region C2 in the interpolation straight line L1, the degree of wear is determined to be 100% in any part of the line segment.

  An input point P3 that cannot draw a perpendicular line L2 to the interpolation straight line L1 is determined as an error. In order to reduce errors, the interpolation straight line L1 may be extended to the increase direction side of the unused area C1 to provide a margin. The interpolation straight line L1 can be extended also in the decreasing direction side of the used area C2.

  FIG. 7 is a diagram showing the relationship between the aspect ratio (width / length) of sample data and the number of holes drilled in the same object in the same environment. The vertical axis shows the aspect ratio of the sample data, and the horizontal axis shows the number of holes formed. In FIG. 7, the drills located on the first stage are 0 holes, 1000 holes, 2000 holes, 4000 holes, the drills located on the second stage are 0 holes, 1000 holes, 2000 holes, 3333 holes, and are located on the third stage. A plurality of sampled aspect ratios are plotted in each of a total of 11 states, ie, 0 hole, 1000 hole, and 2000 hole. Here, the state to be used is set to 4000 holes in the first stage, 3333 holes in the second stage, and 2000 holes in the third stage.

  In FIG. 7, the average value is obtained for each state, and the average values are connected in each of the first stage, the second stage, and the third stage to derive a transition line. Here, when each transition line is observed, it is understood that the wear is greatly caused at the initial stage when the hole is started, and the wear is reduced as the number of holes to be used is approached.

  FIG. 8 is a diagram for explaining a second processing example for identifying the degree of wear of a drill based on start point information and end point information. In the first processing example shown in FIG. 6, the start point P1 and the end point P2 are connected by an interpolation line. In the second processing example, they are connected by a transition line L3 obtained by the method shown in FIG. . The transition line L3 wears greatly in the region near the start point P1, and the wear of the width decreases as the end point P2 is approached. Although the transition curve is shown in FIG. 8, the representative points (for example, average points) in each state as shown in FIG. 7 may be connected by straight lines.

  The determination unit 38 can identify the degree of wear of the inspection target drill from the positional relationship between the transition line L3 and the input point P3. For example, a line is drawn perpendicularly to the interpolation straight line L1 from the input point P3, and an intersection point P5 between the line and the transition line L3 is obtained. The degree of wear can be specified by how much the intersection point P5 is located on the transition line L3.

  FIG. 9 shows an example of a drill inspection result screen 50 displayed on the display unit 40. This screen 50 displays at least the corresponding stage of the drill to be inspected and the degree of wear at that stage. The stage column 52 indicates the current stage corresponding to the drill to be inspected, and in the example of FIG. 9 indicates that it corresponds to the second stage. The usage status column 54 indicates the usage status of the drill, and displays whether it is unused, in use, or not available. The first wear degree column 56 displays the wear degree in the stage, here the second stage, as a numerical value. The second wear level column 58 displays the wear level at the stage with a gauge.

  FIG. 10 is a flowchart showing the basic operation of the drill inspection apparatus 100 according to the present embodiment. The image processing unit 32 adjusts the density value of the cutting edge image of the drill imaged by the imaging unit 20 (S60). The image processing unit 32 aligns the binarized image by adjusting the density value (S62). The subsequent processing may be performed using the original image without adjusting the density value. The measurement unit 34 measures the shape information of the cutting edge region in the image processed by the image processing unit 32 (S64). The determination unit 38 compares the measured shape information of the cutting edge region with the reference data registered in the storage unit 36 (S66). The determination unit 38 determines the state of the cutting edge of the inspection target drill as a result of the collation (S68). For example, identify which stage in the life cycle the drill is in.

  As described above, according to the present embodiment, the state of the drill can be accurately determined by simple processing. That is, since the stage on the life cycle to which the drill to be inspected can be quantitatively determined using shape information such as the length and width of the cutting edge region, it is possible to accurately determine the timing of polishing and discarding Can do. Since the determination can be made quantitatively, the determination can be made more accurately than the polishing or discard timing determination depending on the number of holes.

  In addition, since a value that can be easily measured, such as shape information including the length and width of the cutting edge region, is used as a parameter, it can be determined by simple processing, and high-speed processing is possible.

  In the present embodiment, the degree of wear can be estimated. The above-mentioned Patent Document 1 only performs processing for detecting defective products, and cannot specify the degree of wear.

  In addition, as shown in FIG. 5, the region divided by the shape information of the cutting edge region statistically obtained from the sample data of each state is good for specifying the stage, and corresponds to the inspection target drill. The stage to be performed can be accurately determined.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  Hereinafter, typical modifications will be described. In this modification, in addition to the shape information such as the length and width of the cutting edge region, the accuracy is further improved by adding other parameters. In this modification, the parameters obtained from the shape curve obtained by measuring the widths X1 to Xm of the cutting blades included in the cutting edge region in the longitudinal direction as shown in FIG. 4 as additional parameters are used. More specifically, an area obtained by integrating the width of the cutting edge included in the blade edge region by a predetermined number of rows in the longitudinal direction is used.

  The storage unit 36 further retains the area obtained by integrating the widths X1 to Xm of the cutting blades included in the cutting edge region by a predetermined number of rows in the longitudinal direction (m rows) as a part of the reference data, in units of stages. To do. Here, the predetermined number of rows may be the number of all pixels from the edge to the tip of each cutting edge, or all the lines from the edge of one cutting edge that is symmetrical to the edge of the other cutting edge. It may be the number of pixels, or about several tens of pixels from the edge of each cutting edge. In addition, you may obtain | require the said area about both among two cutting blades, and you may obtain | require an area only about one side.

  The measuring unit 34 measures the width of the cutting edge included in the cutting edge region of the drill to be inspected by at least a predetermined number of rows in the longitudinal direction.

  The storage unit 36 can use the start point information and the end point information as the reference data. At that time, the information is defined by three parameters obtained by adding the area to the length and width of the cutting edge region. Specifically, the average value of the length, width and area of the cutting edge region can be calculated from a plurality of sampling images of unused drills to obtain the center of gravity, which can be used as starting point information. Similarly, the average value of the length, width and area of the cutting edge region can be calculated from a plurality of sampling images of the drill to be used, and the center of gravity can be obtained, which can be used as end point information.

  The storage unit 36 may further hold, for each stage on the life cycle of the drill, the change characteristics defined by the length, width, and area of the cutting edge region due to the use of the drill. The knowledge considered in the change characteristics in the two-dimensional space defined by the above-described length and width can be extended and used for the change characteristics.

  The determination unit 38 obtains the area by integrating the widths X1 to Xm of the cutting blades corresponding to the number of rows measured by the measurement unit 34. When obtaining this area, the amount of calculation can be reduced by smoothing the shape curve connecting the widths X1 to Xm of the cutting edge using a predetermined filter. Details will be described later.

  The determination unit 38 specifies the stage to which the drill to be inspected corresponds by comparing the length, width, and area measured by the measurement unit 34 with the reference data held in the storage unit 36.

  For example, when the start point information of the first half stage and the end point information of the second half stage are held as reference data for each stage corresponding to the number of polishing times, it can be specified as follows. The determination unit 38 specifies the start point information or end point information defined by the three-dimensional coordinates that is closest to the three-dimensional coordinates defined by the measured length, width, and obtained area of the cutting edge region, and starts the determination. It is specified whether the point information or the end point information is located in the first half stage or the second half stage of the Nth stage. In addition, it can be specified by the following method whether it is located in the first half stage or the second half stage of the Nth stage. That is, the shape information of the cutting edge region obtained from the sampling images of the unused drills and the drills to be used for each polishing number is plotted in the three-dimensional space. Based on the result, a predetermined linear classifier or non-linear classifier such as a neural network or a support vector machine is constructed. Thus, the three-dimensional space can be divided into a first stage to an Mth (M = maximum polishing count + 1) stage divided into a first half stage and a second half stage, respectively. In this case, data for specifying each region, such as a boundary line of each region, is the reference data.

  Further, the determination unit 38 determines the degree of wear in the three-dimensional space defined by the length, width and area with the same knowledge as specifying the degree of wear in the two-dimensional space defined by the length and width described above. Can be identified.

  FIG. 11 is a diagram showing a shape curve connecting the widths X1 to Xm of the cutting blades. The vertical axis represents the width X1 to Xm of the cutting edge as a deviation, and the horizontal axis represents the number of rows in the longitudinal direction of the cutting edge. The deviation here is a value obtained by subtracting the average value of the widths X1 to Xm of the cutting blades from the widths X1 to Xm of the respective cutting blades. Referring to FIG. 11, it can be seen that the edge portion and the tip portion of the cutting edge become thinner. In addition, the determination part 38 can determine with a defect | deletion, when the deviation which exceeds the threshold value calculated | required experimentally and empirically appears. Alternatively, it may be determined that there is a defect when there is a change between adjacent deviations that exceeds an experimentally and empirically determined threshold value.

  FIG. 12 is a diagram illustrating a state in which the area is obtained from the shape curve connecting the cutting blade widths X1 to Xm. FIG. 12 shows an example in which the area is obtained by integrating the widths X1 to Xm of the cutting edge defined by the deviation for 40 lines from the edge. When obtaining this area, the shape curve may be smoothed using a Gaussian filter. Each deviation is normalized to a value from 0 to 1. Alternatively, standard deviation or variance may be used instead of area.

  FIG. 13 is a diagram showing sample data of the area obtained from the shape curve connecting the widths X1 to Xm of the cutting blades. In FIG. 13, sample data is obtained for each of the seven states of the drill including the deficient state described in FIG. Each area is obtained by integrating 40 lines from the edge. It can be seen that there is a certain tendency for each state. Naturally, an unused drill tends to have a large area regardless of the number of times of polishing, and a used drill with advanced wear tends to have a small area.

  As described above, according to the present modification, the accuracy of inspection can be further improved as compared with the above-described embodiment. That is, in addition to the length and width of the cutting edge region, the above-mentioned area that is significant for specifying the stage can be included in the parameter, so that it can be specified with higher accuracy which stage it corresponds to. Moreover, the defect state can be easily detected.

  In the above modification, in addition to the length and width of the cutting edge region, the area obtained from the shape curve connecting the widths X1 to Xm of the cutting edge is used, but other parameters may be adopted. For example, the shape curve itself connecting the widths X1 to Xm of the cutting edge may be used as a parameter. The determination unit 38 compares each point constituting the shape curve measured by the measurement unit 34 with each corresponding point constituting the shape curve stored in the storage unit 36, and the difference is experimental and empirical. It is possible to determine that a region including a point exceeding the threshold value obtained in the above is missing. Moreover, you may use the average value, dispersion | distribution, or standard deviation of the width X1-Xm of a cutting blade as a parameter. Further, the width X1 to Xm of the cutting edge included in the blade edge region obtained from the captured image, the average value of the difference from the width of the corresponding cutting edge of the reference image, the variance, the standard deviation, or the curve connecting these differences An area may be used. Further, instead of the cutting edge widths X1 to Xm, the same parameters may be used for the cutting blade lengths Y1 to Xp. Furthermore, instead of the three-dimensional parameter space, a parameter space of four or more dimensions may be used in combination.

  Another modification will be described. In this modification, in addition to shape information such as the length, width, and area of the cutting edge region, or by using other parameters instead of at least one of them, the accuracy is further improved. is there. In this modification, as an additional parameter, the tangent and angle of the contour of the cutting edge region are measured and used as parameters. Specific examples are shown below.

  As shown in FIG. 2 above, the edge of the drill has a sharp corner before use, whereas the one with advanced wear becomes smooth. This property is extracted as a directional characteristic using a Gabor filter. That is, a horizontal component is extracted by applying a Gabor filter to the blade edge image, and a straight line is extracted by performing a Hough transform on the component. The slope of the straight line is set as the parameter. This parameter can be included as part of the reference data.

Here, the Gabor filter will be described. The following (Formula 1) shows a Gabor function.
F (x, y) = e−π (x2a2 + y2b2) cos (u + v) (Equation 1)
u = f cos θ, v = fsin θ, f: frequency

  The output image F (x, y) is considered to represent the input image with a wavelet of the Gabor function, and the range characteristics of the wavelet can be changed by the parameters a and b, and the periodic characteristics can be changed by the parameters u and v. . As described above, the Gabor filter can have orientation selectivity by changing the filter direction, and can extract from the overall feature to the local feature by changing the filter frequency.

  In the above-described embodiment, the determination unit 38 calculates a simple Euclidean distance when collating the coordinates obtained by measurement with the coordinates corresponding to the start point information or the end point information, and starts the closest Point information or end point information was obtained. In this respect, the Mahalanobis distance may be calculated in consideration of the variance of the learning data, that is, the spread.

  9 shows an example of the inspection result screen 50 of one drill. FIG. 14 is a diagram illustrating an example of a plurality of drill inspection result screens 60 displayed on the display unit 40. This screen 60 is a display method suitable for a case where a plurality of drills are collected in a cartridge and continuously inspected. FIG. 14 shows the inspection result when a total of 16 drills mounted on a 4 × 4 cartridge are continuously inspected on one screen. Each display window 61 indicates the degree of wear of each drill. The degree of wear is visually indicated by the size of the filled area. In addition, the degree of wear may be displayed by color coding. For example, a display method is possible in which the closer to red, the higher the degree of wear is indicated. The display form of FIG. 14 and the display form of FIG. 9 may be displayed together so that the corresponding stage can be recognized on the same screen.

It is a figure for demonstrating the stage on the life cycle of a drill. It is the figure which imaged the cutting-edge of the drill in the unused state of a new article (0 grinding | polishing) in the direction in alignment with a rotating shaft. It is the figure which imaged the blade edge | tip of the drill in the used state of a new article (0 grinding | polishing). It is the figure which imaged the blade edge | tip of the drill in the unused state after one grinding | polishing. It is the figure which imaged the blade edge of the drill in the used state after one grinding. It is the figure which imaged the blade edge | tip of the drill in the unused state after grinding | polishing twice. It is the figure which imaged the blade edge of the drill in the used state after grinding twice. It is the figure which imaged the blade edge of the drill in a deficient state. It is a figure which shows the structure of the drill inspection apparatus in embodiment of this invention. It is a figure for demonstrating the parameter specified from the image containing a blade edge | tip area | region. It is the figure which plotted sample data in the two-dimensional parameter space prescribed | regulated by the shape information of the blade edge | tip area | region. It is a figure for demonstrating the 1st process example for specifying the grade of wear of a drill based on start point information and end point information. It is a figure which shows the relationship between the aspect-ratio (width / length) of sample data, and the number of vacant holes. It is a figure for demonstrating the 2nd process example for specifying the grade of wear of a drill based on start point information and end point information. It is a figure which shows an example of the test result screen of the drill displayed on a display part. It is a flowchart which shows the basic operation | movement of the drill inspection apparatus which concerns on this Embodiment. It is a figure which shows the shape curve which tied the width | variety of the cutting blade. It is a figure which shows a mode that an area is calculated | required from the shape curve which tied the width | variety of a cutting blade. It is a figure which shows the sample data of the area obtained from the shape curve which tied the width | variety of a cutting blade. It is a figure which shows an example of the test result screen of multiple drills displayed on a display part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 drill, 20 imaging part, 30 calculating part, 32 image processing part, 34 measuring part, 35 setting part, 36 memory | storage part, 38 determination part, 40 display part, 100 drill inspection apparatus.

Claims (7)

A setting unit that sets start point information generated by sampling multiple pieces of shape information of the edge area of an unused drill and end point information generated by sampling multiple pieces of shape information of the edge area of a drill that should be used When,
A storage unit configured to store the start point information and the end point information set by the setting unit;
A measuring unit for measuring shape information of the blade edge region in the image of the blade edge of the imaged drill;
Based on the shape information measured by the measurement unit and the start point information and the end point information held in the storage unit, a determination unit that specifies the degree of wear of the imaged drill by calculation,
A drill inspection apparatus comprising:   The determination unit virtually forms a coordinate space with the elements constituting the shape information as coordinate axes, and in the coordinate space, the start coordinate position of the start point information and the end coordinate position of the end point information, The drill inspection apparatus according to claim 1, wherein a degree of wear of the imaged drill is specified from a positional relationship with the input coordinate position of the shape information measured by the measurement unit.   The determination unit draws an interpolation line between the start coordinate position and the end coordinate position, draws a perpendicular line from the input coordinate position to the interpolation line, and specifies the degree of wear according to the position of the intersection. The drill inspection apparatus according to claim 2, wherein: The storage unit further holds a transition function indicating a transition state of shape information of the cutting edge region from an unused state to a used state,
The drill inspection apparatus according to claim 2, wherein the determination unit specifies the degree of wear from a positional relationship between a transition line derived from the transition function and the input coordinate position.   5. The drill inspection apparatus according to claim 2, wherein the coordinate space is a two-dimensional space defined by a length and a width of the cutting edge region. The storage unit holds the start point information and the end point information for each of a plurality of stages on a life cycle corresponding to the number of times of drilling,
6. The determination unit according to claim 1, wherein the determination unit specifies a stage to which the imaged drill corresponds and a degree of wear in the stage based on shape information measured by the measurement unit. The drill inspection device according to Crab. The storage section virtually forms a coordinate space with the elements constituting the shape information as coordinate axes, and in the coordinate space, the start coordinate position of the start point information and the end coordinate position of the end point information are set to the stage. Hold every
The determination unit specifies a coordinate position where the input coordinate position in the coordinate space of the shape information measured by the measurement unit is the closest among the start coordinate position and the end coordinate position held for each stage. The drill inspection apparatus according to claim 6, wherein the stage to which the coordinate position belongs is identified as a stage to which the imaged drill corresponds.