HARDNESS TESTER AND METHOD FOR HARDNESS TEST

The hardness tester includes a data obtainer obtaining sample shape data that can specify a shape of a sample; an image capture controller controlling a CCD camera to capture an image of the surface of the sample and obtaining image data of the sample; a matching performer associating the sample shape data obtained by the data obtainer with the image data of the sample obtained by the CCD camera; an indentation former forming an indentation with an indenter in a test position set on the sample shape data after the sample shape data and the image data of the sample have been associated by the matching performer; and a hardness value calculator calculating a hardness value of the sample based on the indentation captured with the CCD camera after the indentation has been formed by the indentation former.

DETAILED DESCRIPTION OF THE INVENTION

Hereafter, details of an embodiment of the present invention are described with reference to the drawings. Moreover, in the following description, an X direction is defined as a left-right direction, a Y direction is defined as a front-back direction, and a Z direction is defined as an up-down direction inFIG. 1. In addition, an X-Y plane is defined as a horizontal plane.

A hardness tester100is a Vickers hardness tester, for example, that includes an indenter14a(seeFIG. 3) having a rectangular planar shape. As shown inFIGS. 1 to 4, the hardness tester100is configured with a hardness tester main body10, a controller6, an operator7, a monitor8, and a data obtainer9.

As shown inFIG. 2, the tester main body10includes a hardness measurer1measuring hardness of a sample S; a sample stage2on which the sample S is placed; an XY stage3displacing the sample stage2; an AF stage4for focusing on a surface of the sample S; and an elevator mechanism5raising and lowering the sample stage2(the XY stage3and the AF stage4).

As shown inFIG. 3, the hardness measurer1is configured with an illuminating device11illuminating the surface of the sample S; a CCD camera12capturing an image of the surface of the sample S; and a turret16. The turret16includes an indenter column14, which includes the indenter14a,and a field lens15. The turret16is capable of switching between the indenter column14and the field lens15by rotating.

The illuminating device11shines a light to illuminate the surface of the sample S. The light shone by the illuminating device11reaches the surface of the sample S via a lens1a,a half mirror1d, a mirror1e, and the field lens15.

Based on reflected light input from the surface of the sample S via the field lens15, the mirror1e, the half mirror1d, a mirror1g, and a lens1h, the CCD camera12obtains image data by capturing an image of the surface of the sample S as well as the indentation formed in the surface of the sample S by the indenter14a.The CCD camera12outputs to the controller6the obtained image data via a frame grabber17that is capable of simultaneously accumulating and storing image data having a plurality of frames. Thus, the CCD camera12is an image capturer in the present invention.

The indenter column14is displaced toward the sample S placed on the sample stage2by a load mechanism (not shown in the drawings), which is driven in response to a control signal output by the controller6. The indenter14a,provided on a forefront end of the indenter column14, is pressed against the surface of the sample S with a predetermined test force. The present embodiment uses a quadrangular pyramidal Vickers indenter (with opposing angles of 136±0.5°).

The field lens15is a collective lens, each lens being configured with a different magnification. A plurality of the field lenses15are retained on a bottom surface of the turret16. The field lenses15are arranged above the sample S by rotating the turret16. Thereby, the light shone by the illuminating device11uniformly illuminates the surface of the sample S.

The turret16is configured so as to enable the indenter column14and the plurality of field lenses15to be attached to the bottom surface thereof. The turret16is also configured to be capable of arranging any one of the indenter column14and the plurality of field lenses15above the sample S by rotating the turret16around a Z-axis direction. Specifically, the indentation can be formed in the surface of the sample S by arranging the indenter column14above the sample S, and the formed indentation can be observed by arranging the field lenses15above the sample S.

The sample S is placed on an upper surface of the sample stage2and is fixed in place with a sample holder2a.The XY stage3is driven by a drive mechanism (not shown in the drawings) driven in response to the control signal output by the controller6. The XY stage3then displaces the sample stage2in a direction (X and Y directions) perpendicular to the displacement direction (Z direction) of the indenter14a.The AF stage4is driven in response to the control signal output by the controller6. The AF stage4then minutely raises and lowers the sample stage2based on the image data captured by the CCD camera12to focus on the surface of the sample S. The elevator mechanism5is driven in response to the control signal output by the controller6. The elevator mechanism5then changes a relative distance between the sample stage2and the field lens15by displacing the sample stage2(the XY stage3and the AF stage4) in the Z direction.

The operator7is configured with a keyboard71and a mouse72. The operator7receives an operation input by the user during a hardness test. In addition, when a predetermined user input operation is received by the operator7, a predetermined operation signal corresponding to the input operation is generated and output to the controller6. Specifically, the operator7receives the user's operation to select conditions determining a focus position of the indentation. The operator7also receives the user's operation to designate a range of displacement (a range of relative distance between the sample stage2and the field lens15) of the sample stage2(the elevator mechanism5and the AF stage4). In addition, the operator7receives the user's operation to input a test condition value when carrying out the hardness test with the hardness tester100. The input test condition value is sent to the controller6. Herein, the test condition value is a value such as a material of the sample S, a test force (N) loaded on the sample S by the indenter14a,or a magnification power of the field lens15, for example. In addition, the operator7receives the user's operation to select one of a manual mode, in which the focus position of the indentation is manually determined, and an automatic mode, in which the determination is made automatically. Moreover, the operator7receives the user's operation to program a test position when carrying out the hardness test.

The monitor8is configured with a display device such as an LCD, for example. The monitor8displays, for example, settings for the hardness test input on the operator7, results of the hardness test, and an image captured by the CCD camera12of the surface of the sample S and the indentation formed in the surface of the sample S. Thus, the monitor8is a display in the present invention.

The data obtainer9is an interface that performs transmission and reception of various data (video signal and audio signal, for example) with an external device. Examples of the data obtainer9include, for example, a USB, HDMI, Bluetooth, wired LAN, wireless LAN, and the like. The data obtainer9obtains, for example, sample shape data that can specify the shape of the sample S. The sample shape data is, for example, vector data or bitmap data prepared by CAD (Computer Aided Design). The sample shape data is obtained from, for example, a magnetic or optical recording medium such as a CD-ROM (Compact Disk ROM) or DVD-ROM (Digital Versatile Disc ROM) detachably mounted in the data obtainer9, a server connected via wireless communication, and the like. Thus, the data obtainer is a data obtaining component of the present invention.

As shown inFIG. 4, the controller6is configured to include a CPU61, a RAM62, and a memory63. The controller6performs operation control for performance of a predetermined hardness test by executing a predetermined program stored in the memory63.

The CPU61retrieves a processing program stored in the memory63, then opens and executes the processing program in the RAM62. The CPU61thus performs overall control of the hardness tester100. The RAM62opens the processing program executed by the CPU61in a program storage region within the RAM62and stores, in a data storage region, input data and processing results generated when the processing program is executed. The memory63includes, for example, a recording medium (not shown in the drawings) storing a program, data, and the like. The recording medium is configured with a semiconductor memory and the like. In addition, the memory63stores various kinds of data, various kinds of processing programs, and data processed by running the processing programs that allow the CPU61to perform overall control of the hardness tester100. Moreover, the memory63stores the sample shape data obtained by the data obtainer9.

Next, operations of the hardness tester100according to the present embodiment are described with reference to the flow chart ofFIG. 5. First, sample shape data D1 is obtained (step S1: data obtainment). Specifically, the CPU61controls the data obtainer9so that the data obtainer9obtains the sample shape data D1 of the sample S, which is subjected to the hardness test. The sample shape data D1 obtained in step S1is shape data including a contour of the entire sample S and enables determinations to be made for the inside and the outside of the sample S. Further, in the present embodiment, as shown inFIG. 6, test positions P, . . . are programmed on the sample shape data D1 by a user in advance.

Next, image data D2 of the sample S is obtained (step S2: image capturing). Specifically, when the field lens15has been positioned above the sample S by rotating the turret16, first the CPU61displaces the XY stage3so as to position a predetermined area on the surface of the sample S directly beneath the field lens15. Next, the CPU61raises and lowers the AF stage4to perform automatic focusing on the surface of the sample S based on the image data obtained by the CCD camera12. Then, in a state where automatic focusing is performed on the surface of the sample S, the CPU61captures an image of the surface of the sample S with the CCD camera12to obtain the image data D2 of the sample S. The CPU61displays an image G of the surface of the sample S on the monitor8based on the obtained image data D2 of the sample S (seeFIG. 7). Specifically, the CPU61is an image capture controller of the present invention controlling the CCD camera12to capture an image of the surface of the sample S and obtain the image data D2 of the sample S. Further, the CPU61is a display controller of the present invention displaying the image G of the surface of the sample S on the monitor8based on the image data D2 of the sample S captured by the CCD camera12.

Next, a matching process is performed between the sample shape data D1 and the image data D2 of the sample S (step S3: matching). Specifically, the CPU61performs matching that associates the sample shape data D1 obtained in step S1with the image data D2 of the sample S obtained in step S2. In the present embodiment, as shown inFIG. 7, only a portion of the image data D2 of the sample S is obtained due to a field of view of the field lens15. Accordingly, matching is performed by comparing the obtained portion of image data with the contour of the sample S included in the sample shape data D1 and appropriately correcting differences in X and Y directions and a rotation direction. Thereby, as shown inFIG. 8, the test positions set on the sample shape data D1 are displayed on the monitor8overlapped on the image G based on the image data D2 of the sample S. Specifically, the CPU61is a matching performer of the present invention associating the sample shape data D1 obtained by the data obtainer9with the image data D2 of the sample S obtained by the CCD camera12. Since this matching enables reference to the sample shape data D1, it becomes possible to understand not only the test positions in a portion of the sample S but in the entire sample S. Thus, hardness testing with respect to the entire sample S becomes possible without obtaining image data of the entire sample S.

Next, an indentation is formed (step S4: indentation formation) with the indenter14ain the test positions P, . . . set on the sample shape data D1. Specifically, first, the CPU61moves the sample S (sample stage2) by referring to the test positions on the sample shape data D1 so that a predetermined test position (test starting point for an initial cycle) is placed in a position opposite to the indenter14a.The CPU61then forms an indentation in the test position with the indenter14a.Thus, the CPU61is an indentation former of the present invention creating indentations in the test positions P, . . . set on the sample shape data D1 with the indenter14aafter the sample shape data D1 and the image data D2 of the sample S have been associated in step S3.

Next, a hardness value of the sample S is calculated (step S5: hardness value calculation). Specifically, when the field lens15has been positioned above the sample S by rotating the turret16, the CPU61captures an image of the surface of the sample S with the CCD camera12to obtain image data. The CPU61then analyzes the image data of the surface of the sample S output from the CCD camera12to measure the length of the diagonal lines of the indentation formed in the surface of the sample S. Then, the CPU61calculates the hardness value of the sample S based on the measured length of the diagonal lines. Thus, the CPU61is a hardness value calculator of the present invention calculating the hardness value of the sample S based on the indentation captured with the CCD camera12after the indentation has been formed in step S4.

As described above, the hardness tester100according to the present embodiment includes the data obtainer9obtaining the sample shape data D1 capable of specifying the shape of the sample S, the image capture controller (CPU61) controlling the CCD camera12to capture an image of the surface of the sample S and obtain the image data D2 of the sample S, the matching performer (CPU61) associating the sample shape data D1 obtained by the data obtainer9with the image data D2 of the sample S obtained by the CCD camera12, the indentation former (CPU61) forming an indentation with the indenter14ain the test positions P, . . . set on the sample shape data D1 after the sample shape data D1 is associated with the image data D2 of the sample S by the matching performer, and the hardness value calculator (CPU61) calculating the hardness value of the sample S based on the indentation, the image of which is captured by the CCD camera12after the indentation is formed by the indentation former. Thus, according to the hardness tester100of the present embodiment, the sample shape data D1 capable of specifying the shape of the sample S can be obtained and used, and thus the sample shape data D1 prepared before the testing can be effectively utilized, enabling an efficient hardness test.

Further, according to the hardness tester100of the present embodiment, the sample shape data D1 capable of specifying the shape of the sample S can be obtained and used, and thus it is possible to automatically determine the inside and outside of the sample S. Therefore, it is possible to prevent hardness testing from being performed in a position beyond the range of the sample S.

Moreover, according to the hardness tester100of the present embodiment, the sample shape data D1 on which the test positions P, . . . are programmed by the user in advance can be loaded to form an indentation in the test positions P, . . . set on the sample shape data D1.Therefore, it becomes possible to reduce setup for a hardness test and to more efficiently perform the hardness test.

In addition, the hardness tester100according to the present embodiment further includes the display controller (CPU61) displaying on the monitor8the image G of the surface of the sample S based on the image data D2 of the sample S obtained by the CCD camera12. Thus, the image G and the like after matching can be displayed, and the user can visually identify the test positions P, . . . overlapped and displayed on the image G.

Above, a concrete description was given based on the embodiment according to the present invention. However, the present invention is not limited to the above-described embodiment and may be modified without departing from the scope of the invention.

For example, in the above-described embodiment, after the sample shape data D1 is obtained in step S1inFIG. 5, the image data D2 of the sample S is obtained in step S2. However, the present invention is not limited to this. For example, after the image data D2 of the sample S is obtained in step S1, the sample shape data D1 may be obtained in step S2.

In addition, the test positions P, . . . are programmed on the sample shape data D1 in advance by the user in the above-described embodiment. However, the present invention is not limited to this. For example, when the test positions P, . . . are not yet programmed on the sample shape data D1 in step S1inFIG. 5, after the sample shape data D1 is obtained, the sample shape data D1 may be displayed on the monitor8to program the test positions P, . . . on the sample shape data D1 via the operator7. In this case, the operator7is a test position setter of the present invention setting the test positions P, . . . on the sample shape data D1 obtained by the data obtainer9. By programming the test positions P, . . . on the sample shape data D1, programming can be performed on a clearer image without unnecessary patterning, scratches, and the like, as compared to a conventional case in which the test positions P, . . . are programmed on the image data D2 of the sample S.

Moreover, in the above-described embodiment, the monitor8displayed the image G of the surface of the sample S based on the image data D2 of the sample S and the image G after matching the sample shape data D1 with the image data D2 of the sample S. However, the present invention is not limited to this. For example, a configuration is possible in which the monitor8is not included and the above-described image G and the like is not displayed. Moreover, in the above-described embodiment, the monitor8displays the contour of the sample S and the programmed test (planned) positions P, . . . ; however, the present invention is not limited to this. For example, in addition to the above displays, a test execution position, a hardness value, a hardness distribution contour map, or test results such as a color or colored band according to hardness may be displayed based on an indentation captured by the CCD camera12and the hardness value of the sample S calculated by the hardness value calculator. With the monitor8displaying the test results as describe above, the test results can be reported to the user in a detailed and easy to understand manner.

Moreover, in the above-described invention, the matching process is performed by comparing image data of a portion obtained in step S2inFIG. 5with the contour of the sample S included in the sample shape data D1, and by appropriately correcting differences in the X and Y directions and in the rotation direction; however, the present invention is not limited to this. For example, a wide range image capable of showing the entire sample S may be obtained and compared to the sample shape data D1 to perform the matching process. In addition, even when the sample shape data D1 is shape data showing the contour not of the entire sample S but of only a portion of the sample S, the matching process can be performed by comparing the sample shape data D1 with image data of the obtained portion or the wide range image and by making appropriate corrections. Furthermore, a jig may be set on the sample stage2in advance so that the sample S is placed in a position where the obtained image data D2 of the sample S automatically matches with the sample shape data D1. In addition, the matching process may employ any method as long as matching between the sample shape data D1 and the image data D2 of the sample S is possible.

In addition, modifications may also be made as needed to detailed structures and operations of each component configuring the hardness tester100without departing from the scope of the invention.